Photoperiodism and enzyme rhythms: Kinetic characteristics of the photoperiodic induction of Crassulacean acid metabolism.

Science.gov (United States)

Brulfert, J; Guerrier, D; Queiroz, O

1975-01-01

The effect of photoperiod on Crassulacean acid metabolism (CAM) in Kalanchoe blossfeldiana Poellniz, cv. Tom Thumb, has characteristics similar to its effect on flowering in this plant (although these two phenomena are not causally related). The photoperiodic control of CAM is based on (a) dependance on phytochrome, (b) an endogenous circadian rhythm of sensitivity to photoperiodic signals, (c) a balance between specific positive (increase in enzyme capacity) and negative (inhibitory substances) effects of the photoperiod. Variations in malate content, capacity of phosphoenolpyruvate (PEP) carboxylase, and capacity of CAM inhibitors in young leaves were measured under photoperiodic conditions noninductive for CAM and after transfer into photoperiodic conditions inductive for CAM. Essential characteristics of the photoperiodic induction of CAM are: 1) lag time for malate accumulation; 2) after-effect of the inductive photoperiod on the malate accumulation, on the increase in PEP carboxylase capacity, and on the decrease in the level of long-day produced inhibitors; final levels of malate, enzyme capacity and inhibitor are proportional to the number of inductive day-night cycles; 3) cireadian rhythm in PEP carboxylase capacity with a fixed phase under noninductive photoperiods and a continuously shifting phase under inductive photoperiods, after complex advancing and delaying transients. Kinetic similarities indicate that photoperiodic control of different physiological functions, namely, CAM and flowering, may be achieved through similar mechanisms. Preliminary results with species of Bryophyllum and Sedum support this hypothesis. Phase relationships suggest different degrees of coupling between endogenous enzymic rhythm and photoperiod, depending on whether the plants are under long days or short days.

Circadian rhythms, metabolism, and chrononutrition in rodents and humans

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Chrononutrition is an emerging discipline that builds on the intimate relation between endogenous circadian (24-h) rhythms and metabolism. Circadian regulation of metabolic function can be observed from the level of intracellular biochemistry to whole-organism physiology and even postprandial respon...

Seasonal and daily plasma corticosterone rhythms in American toads, Bufo americanus

International Nuclear Information System (INIS)

Pancak, M.K.; Taylor, D.H.

1983-01-01

Concentrations of corticosterone were measured in the plasma of American toads, Bufo americanus, on a seasonal basis using a radioimmunoassay technique. Two populations of toads, maintained under different light conditions, were monitored to observe the effects of photoperiod on the seasonal rhythm of plasma corticosterone. Under a natural photoperiod toads demonstrated a rhythm consisting of a spring peak and a fall peak in corticosterone concentration. Toads maintained under a 12L:12D photoperiod all year round demonstrated a similar rhythm with peaks in the spring and fall. This suggests that an endogenous (circannual) rhythm of corticosterone may be playing an important role in the seasonal change of overt behavior and physiology of Bufo americanus. A daily rhythm of corticosterone was also detected in toads when blood samples were taken every 4 hr. When compared to a previously published circadian rhythm study of locomotor activity, the surge in corticosterone concentration for the day occurred at 1730 just prior to the peak in locomotor activity

Investigations into the differential reactivity of endogenous and exogenous mercury species in coastal sediments.

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Bouchet, S; Rodriguez-Gonzalez, P; Bridou, R; Monperrus, M; Tessier, E; Anschutz, P; Guyoneaud, R; Amouroux, D

2013-03-01

Stable isotopic tracer methodologies now allow the evaluation of the reactivity of the endogenous (ambient) and exogenous (added) Hg to further predict the potential effect of Hg inputs in ecosystems. The differential reactivity of endogenous and exogenous Hg was compared in superficial sediments collected in a coastal lagoon (Arcachon Bay) and in an estuary (Adour River) from the Bay of Biscay (SW France). All Hg species (gaseous, aqueous, and solid fraction) and ancillary data were measured during time course slurry experiments under variable redox conditions. The average endogenous methylation yield was higher in the estuarine (1.2 %) than in the lagoonal sediment (0.5 %), although both methylation and demethylation rates were higher in the lagoonal sediment in relation with a higher sulfate-reducing activity. Demethylation was overall more consistent than methylation in both sediments. The endogenous and exogenous Hg behaviors were always correlated but the exogenous inorganic Hg (IHg) partitioning into water was 2.0-4.3 times higher than the endogenous one. Its methylation was just slightly higher (1.4) in the estuarine sediment while the difference in the lagoonal sediment was much larger (3.6). The relative endogenous and exogenous methylation yields were not correlated to IHg partitioning, demonstrating that the bioavailable species distributions were different for the two IHg pools. In both sediments, the exogenous IHg partitioning equaled the endogenous one within a week, while its higher methylation lasted for months. Such results provide an original assessment approach to compare coastal sediment response to Hg inputs.

Changes in the 5-HT2A receptor system in the pre-mammillary hypothalamus of the ewe are related to regulation of LH pulsatile secretion by an endogenous circannual rhythm

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Karsch Fred J

2003-01-01

Full Text Available Abstract Background We wanted to determine if changes in the expression of serotonin 2A receptor (5HT2A receptor gene in the premammillary hypothalamus are associated with changes in reproductive neuroendocrine status. Thus, we compared 2 groups of ovariectomized-estradiol-treated ewes that expressed high vs low LH pulsatility in two different paradigms (2 groups per paradigm: (a refractoriness (low LH secretion or not (high LH secretion to short days in pineal-intact Ile-de-France ewes (RSD and (b endogenous circannual rhythm (ECR in free-running pinealectomized Suffolk ewes in the active or inactive stage of their reproductive rhythm. Results In RSD ewes, density of 5HT2A receptor mRNA (by in situ hybridization was significantly higher in the high LH group (25.3 ± 1.4 vs 21.4 ± 1.5 grains/neuron, P 3H-Ketanserin binding (a specific radioligand of the median part of the premammillary hypothalamus tended to be higher in the high group (29.1 ± 4.0 vs 24.6 ± 4.2 fmol/mg tissu-equivalent; P A receptor mRNA and 3H-Ketanserin binding were both significantly higher in the high LH group (20.8 ± 1.6 vs 17.0 ± 1.5 grains/neuron, P Conclusions We conclude that these higher 5HT2A receptor gene expression and binding activity of 5HT2A receptor in the premammillary hypothalamus are associated with stimulation of LH pulsatility expressed before the development of refractoriness to short days and prior to the decline of reproductive neuroendocrine activity during expression of the endogenous circannual rhythm.

Biological and psychological rhythms: an integrative approach to rhythm disturbances in autistic disorder.

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Botbol, Michel; Cabon, Philippe; Kermarrec, Solenn; Tordjman, Sylvie

2013-09-01

Biological rhythms are crucial phenomena that are perfect examples of the adaptation of organisms to their environment. A considerable amount of work has described different types of biological rhythms (from circadian to ultradian), individual differences in their patterns and the complexity of their regulation. In particular, the regulation and maturation of the sleep-wake cycle have been thoroughly studied. Its desynchronization, both endogenous and exogenous, is now well understood, as are its consequences for cognitive impairments and health problems. From a completely different perspective, psychoanalysts have shown a growing interest in the rhythms of psychic life. This interest extends beyond the original focus of psychoanalysis on dreams and the sleep-wake cycle, incorporating central theoretical and practical psychoanalytic issues related to the core functioning of the psychic life: the rhythmic structures of drive dynamics, intersubjective developmental processes and psychic containment functions. Psychopathological and biological approaches to the study of infantile autism reveal the importance of specific biological and psychological rhythmic disturbances in this disorder. Considering data and hypotheses from both perspectives, this paper proposes an integrative approach to the study of these rhythmic disturbances and offers an etiopathogenic hypothesis based on this integrative approach. Copyright © 2013 Elsevier Ltd. All rights reserved.

Introduction: circadian rhythm and its disruption: impact on reproductive function.

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Casper, Robert F; Gladanac, Bojana

2014-08-01

Almost all forms of life have predictable daily or circadian rhythms in molecular, endocrine, and behavioral functions. In mammals, a central pacemaker located in the suprachiasmatic nuclei coordinates the timing of these rhythms. Daily light exposure that affects the retina of the eye directly influences this area, which is required to align endogenous processes to the appropriate time of day. The present "Views and Reviews" articles discuss the influence of circadian rhythms, especially nightly secretion of melatonin, on reproductive function and parturition. In addition, an examination is made of problems that arise from recurrent circadian rhythm disruption associated with changes in light exposure patterns common to modern day society. Finally, a possible solution to prevent disruptions in circadian phase markers by filtering out short wavelengths from nocturnal light is reviewed. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Impact of dispersed coupling strength on the free running periods of circadian rhythms

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Gu, Changgui; Rohling, Jos H. T.; Liang, Xiaoming; Yang, Huijie

2016-03-01

The dominant endogenous clock, named the suprachiasmatic nucleus (SCN), regulates circadian rhythms of behavioral and physiological activity in mammals. One of the main characteristics of the SCN is that the animal maintains a circadian rhythm with a period close to 24 h in the absence of a daily light-dark cycle (called the free running period). The free running period varies among species due to heterogeneity of the SCN network. Previous studies have shown that the heterogeneity in cellular coupling as well as in intrinsic neuronal periods shortens the free running period. Furthermore, as derived from experiments, one neuron's coupling strength is negatively associated with its period. It is unknown what the effects of this association between coupling strength and period are on the free running period and how the heterogeneity in coupling strength influences this free running period. In the present study we found that in the presence of a negative relationship between one neuron's coupling strength and its period, surprisingly, the dispersion of coupling strengths increases the free running period. Our present finding may shed new light on the understanding of the heterogeneous SCN network and provides an alternative explanation for the diversity of free running periods between species.

[Melatonin, synthetic analogs, and the sleep/wake rhythm].

Science.gov (United States)

Escames, G; Acuña-Castroviejo, D

Melatonin, a widespread hormone in the animal kingdom, is produced by several organs and tissues besides the pineal gland. Whilst extrapineal melatonin behaves as a cytoprotective molecule, the pineal produces the hormone in a rhythmic manner. The discovery of melatonin in 1958, and the characterization of its synthesis somewhat later, let to the description of its photoperiodic regulation and its relationship with the biological rhythms such as the sleep/wake rhythm. The suprachiasmatic nuclei are the anatomical seat of the biological clock, represented by the clock genes, which code for the period and frequency of the rhythms. The photoperiod synchronizes the activity of the auprachiasmatic biological clock, which in turn induces the melatonin's rhythm. The rhythm of melatonin, peaking at 2-3 am, acts as an endogenous synchronizer that translates the environmental photoperiodic signal in chemical information for the cells. The sleep/wake cycle is a typical biological rhythm synchronized by melatonin, and the sleep/wake cycle alterations of chronobiological origin, are very sensitive to melatonin treatment. Taking advantage of the chronobiotic and antidepressive properties of melatonin, a series of synthetic analogs of this hormone, with high interest in insomnia, are now available. Melatonin is a highly effective chronobiotic in the treatment of chronobiological alterations of the sleep/wake cycle. From a pharmacokinetic point of view, the synthetic drugs derived from melatonin are interesting tools in the therapy of these alterations.

Circadian rhythms, time-restricted feeding, and healthy aging.

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Manoogian, Emily N C; Panda, Satchidananda

2017-10-01

Circadian rhythms optimize physiology and health by temporally coordinating cellular function, tissue function, and behavior. These endogenous rhythms dampen with age and thus compromise temporal coordination. Feeding-fasting patterns are an external cue that profoundly influence the robustness of daily biological rhythms. Erratic eating patterns can disrupt the temporal coordination of metabolism and physiology leading to chronic diseases that are also characteristic of aging. However, sustaining a robust feeding-fasting cycle, even without altering nutrition quality or quantity, can prevent or reverse these chronic diseases in experimental models. In humans, epidemiological studies have shown erratic eating patterns increase the risk of disease, whereas sustained feeding-fasting cycles, or prolonged overnight fasting, is correlated with protection from breast cancer. Therefore, optimizing the timing of external cues with defined eating patterns can sustain a robust circadian clock, which may prevent disease and improve prognosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Alpha Power Modulates Perception Independently of Endogenous Factors

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Sasskia Brüers

2018-04-01

Full Text Available Oscillations are ubiquitous in the brain. Alpha oscillations in particular have been proposed to play an important role in sensory perception. Past studies have shown that the power of ongoing EEG oscillations in the alpha band is negatively correlated with visual outcome. Moreover, it also co-varies with other endogenous factors such as attention, vigilance, or alertness. In turn, these endogenous factors influence visual perception. Therefore, it remains unclear how much of the relation between alpha and perception is indirectly mediated by such endogenous factors, and how much reflects a direct causal influence of alpha rhythms on sensory neural processing. We propose to disentangle the direct from the indirect causal routes by introducing modulations of alpha power, independently of any fluctuations in endogenous factors. To this end, we use white-noise sequences to constrain the brain activity of 20 participants. The cross-correlation between the white-noise sequences and the concurrently recorded EEG reveals the impulse response function (IRF, a model of the systematic relationship between stimulation and brain response. These IRFs are then used to reconstruct rather than record the brain activity linked with new random sequences (by convolution. Interestingly, this reconstructed EEG only contains information about oscillations directly linked to the white-noise stimulation; fluctuations in attention and other endogenous factors may still modulate brain alpha rhythms during the task, but our reconstructed EEG is immune to these factors. We found that the detection of near-perceptual threshold targets embedded within these new white-noise sequences depended on the power of the ~10 Hz reconstructed EEG over parieto-occipital channels. Around the time of presentation, higher power led to poorer performance. Thus, fluctuations in alpha power, induced here by random luminance sequences, can directly influence perception: the relation between

A riot of rhythms: neuronal and glial circadian oscillators in the mediobasal hypothalamus

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Guilding Clare

2009-08-01

Full Text Available Abstract Background In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc now enables us to track molecular oscillations in numerous tissues ex vivo. Consequently we determined both clock activities and responsiveness to metabolic perturbations of cells and tissues within the mediobasal hypothalamus (MBH, a site pivotal for optimal internal homeostatic regulation. Results Here we demonstrate endogenous circadian rhythms of PER2::LUC expression in discrete subdivisions of the arcuate (Arc and dorsomedial nuclei (DMH. Rhythms resolved to single cells did not maintain long-term synchrony with one-another, leading to a damping of oscillations at both cell and tissue levels. Complementary electrophysiology recordings revealed rhythms in neuronal activity in the Arc and DMH. Further, PER2::LUC rhythms were detected in the ependymal layer of the third ventricle and in the median eminence/pars tuberalis (ME/PT. A high-fat diet had no effect on the molecular oscillations in the MBH, whereas food deprivation resulted in an altered phase in the ME/PT. Conclusion Our results provide the first single cell resolution of endogenous circadian rhythms in clock gene expression in any intact tissue outside the SCN, reveal the cellular basis for tissue level damping in extra-SCN oscillators and demonstrate that an oscillator in the ME/PT is responsive to changes in metabolism.

Clinical Trial of the Effect of Exercise on Resetting of the Endogenous Circadian Pacemaker

National Research Council Canada - National Science Library

Czeisler, Charles

2000-01-01

...: test the hypothesis that multiple nightly bouts of exercise will induce significant delays in the endogenous circadian rhythms of core body temperature, plasma - melatonin, reaction time, alertness...

Two mechanisms of rephasal of circadian rhythms in response to a 180 deg phase shift /simulated 12-hr time zone change/

Science.gov (United States)

Deroshia, C. W.; Winget, C. M.; Bond, G. H.

1976-01-01

A model developed by Wever (1966) is considered. The model describes the behavior of circadian rhythms in response to photoperiod phase shifts simulating time zone changes, as a function of endogenous periodicity, light intensity, and direction of phase shift. A description is given of an investigation conducted to test the model upon the deep body temperature rhythm in unrestrained subhuman primates. An evaluation is conducted regarding the applicability of the model in predicting the type and duration of desynchronization induced by simulated time zone changes as a function of endogenous periodicity.

Uncovering different masking factors on wrist skin temperature rhythm in free-living subjects.

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Antonio Martinez-Nicolas

Full Text Available Most circadian rhythms are controlled by a major pacemaker located in the hypothalamic suprachiasmatic nucleus. Some of these rhythms, called marker rhythms, serve to characterize the timing of the internal temporal order. However, these variables are susceptible to masking effects as the result of activity, body position, light exposure, environmental temperature and sleep. Recently, wrist skin temperature (WT has been proposed as a new index for evaluating circadian system status. In light of previous evidence suggesting the important relationship between WT and core body temperature regulation, the aim of this work was to purify the WT pattern in order to obtain its endogenous rhythm with the application of multiple demasking procedures. To this end, 103 subjects (18-24 years old were recruited and their WT, activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. WT demasking by categories or intercepts was applied to simulate a "constant routine" protocol (awakening, dim light, recumbent position, low activity and warm environmental temperature. Although the overall circadian pattern of WT was similar regardless of the masking effects, its amplitude was the rhythmic parameter most affected by environmental conditions. The acrophase and mesor were determined to be the most robust parameters for characterizing this rhythm. In addition, a circadian modulation of the masking effect was found for each masking variable. WT rhythm exhibits a strong endogenous component, despite the existence of multiple external influences. This was evidenced by simultaneously eliminating the influence of activity, body position, light exposure, environmental temperature and sleep. We therefore propose that it could be considered a valuable and minimally-invasive means of recording circadian physiology in ambulatory conditions.

Increase in Synchronization of Autonomic Rhythms between Individuals When Listening to Music

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Bernardi, Nicolò F.; Codrons, Erwan; di Leo, Rita; Vandoni, Matteo; Cavallaro, Filippo; Vita, Giuseppe; Bernardi, Luciano

2017-01-01

In light of theories postulating a role for music in forming emotional and social bonds, here we investigated whether endogenous rhythms synchronize between multiple individuals when listening to music. Cardiovascular and respiratory recordings were taken from multiple individuals (musically trained or music-naïve) simultaneously, at rest and during a live concert comprising music excerpts with varying degrees of complexity of the acoustic envelope. Inter-individual synchronization of cardiorespiratory rhythms showed a subtle but reliable increase during passively listening to music compared to baseline. The low-level auditory features of the music were largely responsible for creating or disrupting such synchronism, explaining ~80% of its variance, over and beyond subjective musical preferences and previous musical training. Listening to simple rhythms and melodies, which largely dominate the choice of music during rituals and mass events, brings individuals together in terms of their physiological rhythms, which could explain why music is widely used to favor social bonds. PMID:29089898

Circadian rhythms in the pineal organ persist in zebrafish larvae that lack ventral brain

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Goldstein-Kral Lauren

2011-01-01

Full Text Available Abstract Background The mammalian suprachiasmatic nucleus (SCN, located in the ventral hypothalamus, is a major regulator of circadian rhythms in mammals and birds. However, the role of the SCN in lower vertebrates remains poorly understood. Zebrafish cyclops (cyc mutants lack ventral brain, including the region that gives rise to the SCN. We have used cyc embryos to define the function of the zebrafish SCN in regulating circadian rhythms in the developing pineal organ. The pineal organ is the major source of the circadian hormone melatonin, which regulates rhythms such as daily rest/activity cycles. Mammalian pineal rhythms are controlled almost exclusively by the SCN. In zebrafish and many other lower vertebrates, the pineal has an endogenous clock that is responsible in part for cyclic melatonin biosynthesis and gene expression. Results We find that pineal rhythms are present in cyc mutants despite the absence of an SCN. The arginine vasopressin-like protein (Avpl, formerly called Vasotocin is a peptide hormone expressed in and around the SCN. We find avpl mRNA is absent in cyc mutants, supporting previous work suggesting the SCN is missing. In contrast, expression of the putative circadian clock genes, cryptochrome 1b (cry1b and cryptochrome 3 (cry3, in the brain of the developing fish is unaltered. Expression of two pineal rhythmic genes, exo-rhodopsin (exorh and serotonin-N-acetyltransferase (aanat2, involved in photoreception and melatonin synthesis, respectively, is also similar between cyc embryos and their wildtype (WT siblings. The timing of the peaks and troughs of expression are the same, although the amplitude of expression is slightly decreased in the mutants. Cyclic gene expression persists for two days in cyc embryos transferred to constant light or constant dark, suggesting a circadian clock is driving the rhythms. However, the amplitude of rhythms in cyc mutants kept in constant conditions decreased more quickly than in their

Rhythms of mammalian body temperature can sustain peripheral circadian clocks.

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Brown, Steven A; Zumbrunn, Gottlieb; Fleury-Olela, Fabienne; Preitner, Nicolas; Schibler, Ueli

2002-09-17

Low-amplitude temperature oscillations can entrain the phase of circadian rhythms in several unicellular and multicellular organisms, including Neurospora and Drosophila. Because mammalian body temperature is subject to circadian variations of 1 degrees C-4 degrees C, we wished to determine whether these temperature cycles could serve as a Zeitgeber for circadian gene expression in peripheral cell types. In RAT1 fibroblasts cultured in vitro, circadian gene expression could be established by a square wave temperature rhythm with a (Delta)T of 4 degrees C (12 hr 37 degrees C/12 hr 33 degrees C). To examine whether natural body temperature rhythms can also affect circadian gene expression, we first measured core body temperature cycles in the peritoneal cavities of mice by radiotelemetry. We then reproduced these rhythms with high precision in the liquid medium of cultured fibroblasts for several days by means of a homemade computer-driven incubator. While these "in vivo" temperature rhythms were incapable of establishing circadian gene expression de novo, they could maintain previously induced rhythms for multiple days; by contrast, the rhythms of control cells kept at constant temperature rapidly dampened. Moreover, circadian oscillations of environmental temperature could reentrain circadian clocks in the livers of mice, probably via the changes they imposed upon both body temperature and feeding behavior. Interestingly, these changes in ambient temperature did not affect the phase of the central circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus. We postulate that both endogenous and environmental temperature cycles can participate in the synchronization of peripheral clocks in mammals.

Biomorphology and rhythm of seasonal development of the relic species Lobelia dortmanna in oligotrophic lakes of Tver region

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A. G. Lapirov

2017-07-01

Full Text Available This article covers the morphology of the vegetative and generative sphere of a rare relic species, Lobelia dortmanna L. (Lobelioideae. This is the first time that using the modular approach a study has analysed the shoot system of this species and described the structures of all three categories: elementary (EM, universal (UM and basic (OM. This paper describes the life form and analyses the rhythm of seasonal development of the species in the lakes of Tver oblast, and provides data on the seed productivity. As a life form, L. dortmanna is a herbaceous polycarpic, un clearly polycentric shallow-rooted plant with a fibrous root system and non-specialized morphological disintegration. The sympodially growing shoot-system of the plant is formed by two types of different-aged anisotropic replacement shoots: dicyclic vegetative-generative semirosette and annual vegetative rosette shoots. The indicator of actual seed productivity equals on average up to 1621 ± 451 seeds per single vegetative-generative shoot. The module structure of L. dortmanna is presented by 10 variants of elementary modules. The main modules are formed on the basis of a monocarpic dicyclic anisotropic monopodial shoot with the following morpho-functional zones distinguished: 1 the lower zone of inhibition; 2 the recovery zone; 3 the upper zone of inhibition 4 the latent generative zone; 5 the main inflorescence. The functional role of the first three morpho-functional zones of a monocarpic shoot is performed by a minimum number of variants of elementary modules. In the rhythm of seasonal development, the authors distinguished 7 consecutive stages: 1 the period of relative rest; 2 vegetative phase; 3 the phase of budding; 4 flowering; 5 frui ting; 6 secondary activities. By the character of rhythm of seasonal development, L. dortmanna belongs to the group of evergreen plants with a long growing season and middle-late summer flowering.

Effects of exercise on circadian rhythms and mobility in aging Drosophila melanogaster.

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Rakshit, Kuntol; Wambua, Rebecca; Giebultowicz, Tomasz M; Giebultowicz, Jadwiga M

2013-11-01

Daily life functions such as sleep and feeding oscillate with circa 24 h period due to endogenous circadian rhythms generated by circadian clocks. Genetic or environmental disruption of circadian rhythms is associated with various aging-related phenotypes. Circadian rhythms decay during normal aging, and there is a need to explore strategies that could avert age-related changes in the circadian system. Exercise was reported to delay aging in mammals. Here, we investigated whether daily exercise via stimulation of upward climbing movement could improve circadian rest/activity rhythms in aging Drosophila melanogaster. We found that repeated exercise regimen did not strengthen circadian locomotor activity rhythms in aging flies and had no effect on their lifespan. We also tested the effects of exercise on mobility and determined that regular exercise lowered age-specific climbing ability in both wild type and clock mutant flies. Interestingly, the climbing ability was most significantly reduced in flies carrying a null mutation in the core clock gene period, while rescue of this gene significantly improved climbing to wild type levels. Our work highlights the importance of period in sustaining endurance in aging flies exposed to physical challenge. © 2013.

Rhythms of locomotion expressed by Limulus polyphemus, the American horseshoe crab: I. Synchronization by artificial tides.

Science.gov (United States)

Chabot, Christopher C; Skinner, Stephen J; Watson, Winsor H

2008-08-01

Limulus polyphemus, the American horseshoe crab, has an endogenous clock that drives circatidal rhythms of locomotor activity. In this study, we examined the ability of artificial tides to entrain the locomotor rhythms of Limulus in the laboratory. In experiments one and two, the activity of 16 individuals of L. polyphemus was monitored with activity boxes and "running wheels." When the crabs were exposed to artificial tides created by changes in water depth, circatidal rhythms were observed in animals exposed to 12.4-h "tidal" cycles of either water depth changes (8 of 8 animals) or inundation (7 of 8 animals). In experiment three, an additional 8 animals were exposed to water depth changes under cyclic conditions of light and dark and then monitored for 10 days with no imposed artificial tides. Most animals (5) clearly synchronized their activity to the imposed artificial tidal cycles, and 3 of these animals showed clear evidence of entrainment after the artificial tides were terminated. Overall, these results demonstrate that the endogenous tidal clock that influences locomotion in Limulus can be entrained by imposed artificial tides. In the laboratory, these tidal cues override the influence of light/dark cycles. In their natural habitat, where both tidal and photoperiod inputs are typically always present, their activity rhythms are likely to be much more complex.

Circadian and circannual rhythms in the metabolism and ventilation of red-eared sliders (Trachemys scripta elegans).

Science.gov (United States)

Reyes, Catalina; Milsom, William K

2010-01-01

Endogenous circadian and circannual rhythms may exist in the metabolism, ventilation, and breathing pattern of turtles that could further prolong dive times during daily and seasonal periods of reduced activity. To test this hypothesis, turtles were held under seasonal or constant environmental conditions over a 1-yr period, and in each season, V(O)(2) and respiratory variables were measured in all animals under both the prevailing seasonal conditions and the constant conditions for 24 h. Endogenous circadian and circannual rhythms in metabolism and ventilation occurred independent of ambient temperature, photoperiod, and activity, although long-term entrainment to daily and seasonal changes in temperature and photoperiod were required for them to be expressed. Metabolism and ventilation were always higher during the photophase, and the day-night difference was greater at any given temperature when the photoperiod was provided. When corrected for temperature, turtles had elevated metabolic and ventilation rates in the fall and spring (corresponding to the reproductive seasons) and suppressed metabolism and ventilation during winter. The strength of the circadian rhythm varied seasonally, with proportionately larger day-night differences in colder seasons. Daily and seasonal cycles in ventilation largely followed metabolism, although daily and seasonal changes did occur in the breathing pattern independent of levels of total ventilation. These endogenous circadian and circannual changes in metabolism, ventilation, and breathing pattern prolonged dive times at night and in winter and may serve to reduce the costs of breathing and transport and risk of predation.

Daily Rhythms of Hunger and Satiety in Healthy Men during One Week of Sleep Restriction and Circadian Misalignment.

Science.gov (United States)

Sargent, Charli; Zhou, Xuan; Matthews, Raymond W; Darwent, David; Roach, Gregory D

2016-01-29

The impact of sleep restriction on the endogenous circadian rhythms of hunger and satiety were examined in 28 healthy young men. Participants were scheduled to 2 × 24-h days of baseline followed by 8 × 28-h days of forced desynchrony during which sleep was either moderately restricted (equivalent to 6 h in bed/24 h; n = 14) or severely restricted (equivalent to 4 h in bed/24 h; n = 14). Self-reported hunger and satisfaction were assessed every 2.5 h during wake periods using visual analogue scales. Participants were served standardised meals and snacks at regular intervals and were not permitted to eat ad libitum. Core body temperature was continuously recorded with rectal thermistors to determine circadian phase. Both hunger and satiety exhibited a marked endogenous circadian rhythm. Hunger was highest, and satiety was lowest, in the biological evening (i.e., ~17:00-21:00 h) whereas hunger was lowest, and satiety was highest in the biological night (i.e., 01:00-05:00 h). The results are consistent with expectations based on previous reports and may explain in some part the decrease in appetite that is commonly reported by individuals who are required to work at night. Interestingly, the endogenous rhythms of hunger and satiety do not appear to be altered by severe--as compared to moderate--sleep restriction.

Daily Rhythms of Hunger and Satiety in Healthy Men during One Week of Sleep Restriction and Circadian Misalignment

Directory of Open Access Journals (Sweden)

Charli Sargent

2016-01-01

Full Text Available The impact of sleep restriction on the endogenous circadian rhythms of hunger and satiety were examined in 28 healthy young men. Participants were scheduled to 2 × 24-h days of baseline followed by 8 × 28-h days of forced desynchrony during which sleep was either moderately restricted (equivalent to 6 h in bed/24 h; n = 14 or severely restricted (equivalent to 4 h in bed/24 h; n = 14. Self-reported hunger and satisfaction were assessed every 2.5 h during wake periods using visual analogue scales. Participants were served standardised meals and snacks at regular intervals and were not permitted to eat ad libitum. Core body temperature was continuously recorded with rectal thermistors to determine circadian phase. Both hunger and satiety exhibited a marked endogenous circadian rhythm. Hunger was highest, and satiety was lowest, in the biological evening (i.e., ~17:00–21:00 h whereas hunger was lowest, and satiety was highest in the biological night (i.e., 01:00–05:00 h. The results are consistent with expectations based on previous reports and may explain in some part the decrease in appetite that is commonly reported by individuals who are required to work at night. Interestingly, the endogenous rhythms of hunger and satiety do not appear to be altered by severe—as compared to moderate—sleep restriction.

An approximation to the temporal order in endogenous circadian rhythms of genes implicated in human adipose tissue metabolism

Science.gov (United States)

Although it is well established that human adipose tissue (AT) shows circadian rhythmicity, published studies have been discussed as if tissues or systems showed only one or few circadian rhythms at a time. To provide an overall view of the internal temporal order of circadian rhythms in human AT in...

Regulation of behavioral circadian rhythms and clock protein PER1 by the deubiquitinating enzyme USP2

DEFF Research Database (Denmark)

Yang, Yaoming; Duguay, David; Bédard, Nathalie

2012-01-01

Endogenous 24-hour rhythms are generated by circadian clocks located in most tissues. The molecular clock mechanism is based on feedback loops involving clock genes and their protein products. Post-translational modifications, including ubiquitination, are important for regulating the clock...

External and internal controls of lunar-related reproductive rhythms in fishes.

Science.gov (United States)

Takemura, A; Rahman, M S; Park, Y J

2010-01-01

Reproductive activities of many fish species are, to some extent, entrained to cues from the moon. During the spawning season, synchronous spawning is repeated at intervals of c. 1 month (lunar spawning cycle) and 2 weeks (semi-lunar spawning cycle) or daily according to tidal changes (tidal spawning cycle). In species showing lunar-related spawning cycles, oocytes in the ovary develop towards and mature around a specific moon phase for lunar spawners, around spring tides for semi-lunar spawners and at daytime high tides for tidal spawners. The production of sex steroid hormones also changes in accordance with synchronous oocyte development. Since the production of the steroid hormones with lunar-related reproductive periodicity is regulated by gonadotropins, it is considered that the higher parts of the hypothalamus-pituitary-gonad axis play important roles in the perception and regulation of lunar-related periodicity. It is likely that fishes perceive cues from the moon by sensory organs; however, it is still unknown how lunar cues are transduced as an endogenous rhythm exerting lunar-related spawning rhythmicity. Recent research has revealed that melatonin fluctuated according to the brightness at night, magnetic fields and the tidal cycle. In addition, cyclic changes in hydrostatic pressure had an effect on monoamine contents in the brain. These factors may be indirectly related to the exertion of lunar-related periodicity. Molecular approaches have revealed that mRNA expressions of light-sensitive clock genes change with moonlight, suggesting that brightness at night plays a role in phase-shifting or resetting of biological clocks. Some species may have evolved biological clocks in relation to lunar cycles, although it is still not known how lunar periodicities are endogenously regulated in fishes. This review demonstrates that lunar-related periodicity is utilized and incorporated by ecological and physiological mechanisms governing the reproductive success

Dissecting Daily and Circadian Expression Rhythms of Clock-Controlled Genes in Human Blood.

Science.gov (United States)

Lech, Karolina; Ackermann, Katrin; Revell, Victoria L; Lao, Oscar; Skene, Debra J; Kayser, Manfred

2016-02-01

The identification and investigation of novel clock-controlled genes (CCGs) has been conducted thus far mainly in model organisms such as nocturnal rodents, with limited information in humans. Here, we aimed to characterize daily and circadian expression rhythms of CCGs in human peripheral blood during a sleep/sleep deprivation (S/SD) study and a constant routine (CR) study. Blood expression levels of 9 candidate CCGs (SREBF1, TRIB1, USF1, THRA1, SIRT1, STAT3, CAPRIN1, MKNK2, and ROCK2), were measured across 48 h in 12 participants in the S/SD study and across 33 h in 12 participants in the CR study. Statistically significant rhythms in expression were observed for STAT3, SREBF1, TRIB1, and THRA1 in samples from both the S/SD and the CR studies, indicating that their rhythmicity is driven by the endogenous clock. The MKNK2 gene was significantly rhythmic in the S/SD but not the CR study, which implies its exogenously driven rhythmic expression. In addition, we confirmed the circadian expression of PER1, PER3, and REV-ERBα in the CR study samples, while BMAL1 and HSPA1B were not significantly rhythmic in the CR samples; all 5 genes previously showed significant expression in the S/SD study samples. Overall, our results demonstrate that rhythmic expression patterns of clock and selected clock-controlled genes in human blood cells are in part determined by exogenous factors (sleep and fasting state) and in part by the endogenous circadian timing system. Knowledge of the exogenous and endogenous regulation of gene expression rhythms is needed prior to the selection of potential candidate marker genes for future applications in medical and forensic settings. © 2015 The Author(s).

Relationship between variations in the level of endogenous thiols and antioxidant activity of lipids and radiosensitivity of animals of different species

International Nuclear Information System (INIS)

Burlakova, E.B.; Graevskaya, B.M.; Ivanenko, G.F.; Shishkina, L.N.; AN SSSR, Moscow. Inst. Ehvolyutsionnoj Morfologii i Ehkologii Zhivotnykh)

1978-01-01

Initial levels of total and nonprotein sulfhydryl groups and antioxidant activity (AOA) of lipids of the spleen and liver are measured in animals of different species. Radiosensitivity of animals is assessed by the value of LDsub(50/30). No reliable correlation has been revealed between initial levels of endogenous thiols and AOA of lipids. There is a positive correlation between AOA of the spleen lipids and LDsub(50/30) as well as between the level of endogenous thiols and radioresistance of the animal species under study. It is likely that the level of endogenous thiols and AOA of lipids reflect various aspects of cellular metabolism which is responsible for radioresistance of the organism

Endogenous Circadian Regulation of Pro-inflammatory Cytokines and Chemokines in the Presence of Bacterial Lipopolysaccharide in Humans

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Rahman, Shadab A.; Castanon-Cervantes, Oscar; Scheer, Frank A.J.L.; Shea, Steven A.; Czeisler, Charles A.; Davidson, Alec J.; Lockley, Steven W.

2015-01-01

Various aspects of immune response exhibit 24-hour variations suggesting that infection susceptibility and treatment efficacy may vary by time of day. Whether these 24-hour variations are endogenous or evoked by changes in environmental or behavioral conditions is not known. We assessed the endogenous circadian control and environmental and behavioral influences on ex-vivo lipopolysaccharide stimulation of whole blood in thirteen healthy participants under 48 hours of baseline conditions with standard sleep-wake schedules and 40–50 hours of constant environmental and behavioral (constant routine; CR) conditions. Significant 24-hour rhythms were observed under baseline conditions in Monocyte Chemotactic Protein, Granulocyte-Macrophage Colony-Stimulating Factor and Interleukin 8 but not Tumor Necrosis Factor alpha whereas significant 24-hour rhythms were observed in all four immune factors under CR conditions. The rhythm amplitudes, expressed as a percentage of mean, were comparable between immune factors and across conditions. In contrast, the acrophase time (time of the fitted peak) was different between immune factors, and included daytime and nighttime peaks and changes across behavioral conditions. These results suggest that the endogenous circadian system underpins the temporal organization of immune responses in humans with additional effects of external environmental and behavioral cycles. These findings have implications for understanding the adverse effects of recurrent circadian disruption and sleep curtailment on immune function. PMID:25452149

Sleep, circadian rhythm and body weight: parallel developments.

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Westerterp-Plantenga, Margriet S

2016-11-01

Circadian alignment is crucial for body-weight management, and for metabolic health. In this context, circadian alignment consists of alignment of sleep, meal patterns and physical activity. During puberty a significant reduction in sleep duration occurs, and pubertal status is inversely associated with sleep duration. A consistent inverse association between habitual sleep duration and body-weight development occurs, independent of possible confounders. Research on misalignment reveals that circadian misalignment affects sleep-architecture and subsequently disturbs glucose-insulin metabolism, substrate oxidation, leptin- and ghrelin concentrations, appetite, food reward, hypothalamic-pituitary-adrenal-axis activity and gut-peptide concentrations enhancing positive energy balance and metabolic disturbance. Not only aligning meals and sleep in a circadian way is crucial, also regular physical activity during the day strongly promotes the stability and amplitude of circadian rhythm, and thus may serve as an instrument to restore poor circadian rhythms. Endogenicity may play a role in interaction of these environmental variables with a genetic predisposition. In conclusion, notwithstanding the separate favourable effects of sufficient daily physical activity, regular meal patterns, sufficient sleep duration and quality sleep on energy balance, the overall effect of the amplitude and stability of the circadian rhythm, perhaps including genetic predisposition, may integrate the separate effects in an additive way.

Circadian rhythms in sports performance--an update.

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Drust, B; Waterhouse, J; Atkinson, G; Edwards, B; Reilly, T

2005-01-01

We discuss current knowledge on the description, impact, and underlying causes of circadian rhythmicity in sports performance. We argue that there is a wealth of information from both applied and experimental work, which, when considered together, suggests that sports performance is affected by time of day in normal entrained conditions and that the variation has at least some input from endogenous mechanisms. Nevertheless, precise information on the relative importance of endogenous and exogenous factors is lacking. No single study can answer both the applied and basic research questions that are relevant to this topic, but an appropriate mixture of real-world research on rhythm disturbances and tightly controlled experiments involving forced desynchronization protocols is needed. Important issues, which should be considered by any chronobiologist interested in sports and exercise, include how representative the study sample and the selected performance tests are, test-retest reliability, as well as overall design of the experiment.

Transcranial electrical currents to probe EEG brain rhythms and memory consolidation during sleep in humans.

Directory of Open Access Journals (Sweden)

Lisa Marshall

Full Text Available Previously the application of a weak electric anodal current oscillating with a frequency of the sleep slow oscillation (∼0.75 Hz during non-rapid eye movement sleep (NonREM sleep boosted endogenous slow oscillation activity and enhanced sleep-associated memory consolidation. The slow oscillations occurring during NonREM sleep and theta oscillations present during REM sleep have been considered of critical relevance for memory formation. Here transcranial direct current stimulation (tDCS oscillating at 5 Hz, i.e., within the theta frequency range (theta-tDCS is applied during NonREM and REM sleep. Theta-tDCS during NonREM sleep produced a global decrease in slow oscillatory activity conjoint with a local reduction of frontal slow EEG spindle power (8-12 Hz and a decrement in consolidation of declarative memory, underlining the relevance of these cortical oscillations for sleep-dependent memory consolidation. In contrast, during REM sleep theta-tDCS appears to increase global gamma (25-45 Hz activity, indicating a clear brain state-dependency of theta-tDCS. More generally, results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies.

The sublethal effects of endosulfan on the circadian rhythms and locomotor activity of two sympatric parasitoid species.

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Delpuech, Jean-Marie; Bussod, Sophie; Amar, Aurelien

2015-08-01

The organochlorine insecticide endosulfan is dispersed worldwide and significantly contributes to environmental pollution. It is an antagonist of the neurotransmitter gamma-aminobutyric acid (GABA), which is also indirectly involved in photoperiodic time measurement. In this study, we show that endosulfan at a dose as low as LC 0.1 modified the rhythm of locomotor activity of two sympatric parasitoid species, Leptopilina boulardi and Leptopilina heterotoma. The insecticide strongly increased the nocturnal activity of both species and synchronized their diurnal activity; these activities were not synchronized under control conditions. Parasitoids are important species in ecosystems because they control the populations of other insects. In this paper, we discuss the possible consequences of these sublethal effects and highlight the importance of such effects in evaluating the consequences of environmental pollution due to insecticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chorusing, synchrony and the evolutionary functions of rhythm

Directory of Open Access Journals (Sweden)

Andrea eRavignani

2014-10-01

Full Text Available A central goal of biomusicology is to understand the biological basis of human musicality. One approach to this problem has been to compare core components of human musicality (relative pitch perception, entrainment, etc. with similar capacities in other animal species. Here we extend and clarify this comparative approach with respect to rhythm. First, whereas most comparisons between human music and animal acoustic behavior have focused on spectral properties (melody and harmony, we argue for the central importance of temporal properties, and propose that this domain is ripe for further comparative research. Second, whereas most rhythm research in non-human animals has examined animal timing in isolation, we consider how chorusing dynamics can shape individual timing, as in human music and dance, making group behavior key to understand the adaptive functions of rhythm. To illustrate the interdependence between individual and chorusing dynamics, we present a computational model of chorusing agents relating individual call timing with synchronous group behavior. Third, we distinguish and clarify mechanistic and functional explanations of rhythmic phenomena, often conflated in the literature, arguing that this distinction is key for understanding the evolution of musicality. Fourth, we expand biomusicological discussions beyond the species typically considered, providing an overview of chorusing and rhythmic behavior across a broad range of taxa (orthopterans, fireflies, frogs, birds, and primates. Finally, we propose an Evolving Signal Timing hypothesis, suggesting that similarities between timing abilities in biological species will be based on comparable chorusing behaviors. We conclude that the comparative study of chorusing species can provide important insights into the adaptive function(s of rhythmic behavior in our proto-musical primate ancestors, and thus inform our understanding of the biology and evolution of rhythm in human music and

Chorusing, synchrony, and the evolutionary functions of rhythm.

Science.gov (United States)

Ravignani, Andrea; Bowling, Daniel L; Fitch, W Tecumseh

2014-01-01

A central goal of biomusicology is to understand the biological basis of human musicality. One approach to this problem has been to compare core components of human musicality (relative pitch perception, entrainment, etc.) with similar capacities in other animal species. Here we extend and clarify this comparative approach with respect to rhythm. First, whereas most comparisons between human music and animal acoustic behavior have focused on spectral properties (melody and harmony), we argue for the central importance of temporal properties, and propose that this domain is ripe for further comparative research. Second, whereas most rhythm research in non-human animals has examined animal timing in isolation, we consider how chorusing dynamics can shape individual timing, as in human music and dance, arguing that group behavior is key to understanding the adaptive functions of rhythm. To illustrate the interdependence between individual and chorusing dynamics, we present a computational model of chorusing agents relating individual call timing with synchronous group behavior. Third, we distinguish and clarify mechanistic and functional explanations of rhythmic phenomena, often conflated in the literature, arguing that this distinction is key for understanding the evolution of musicality. Fourth, we expand biomusicological discussions beyond the species typically considered, providing an overview of chorusing and rhythmic behavior across a broad range of taxa (orthopterans, fireflies, frogs, birds, and primates). Finally, we propose an "Evolving Signal Timing" hypothesis, suggesting that similarities between timing abilities in biological species will be based on comparable chorusing behaviors. We conclude that the comparative study of chorusing species can provide important insights into the adaptive function(s) of rhythmic behavior in our "proto-musical" primate ancestors, and thus inform our understanding of the biology and evolution of rhythm in human music and

A circadian rhythm of conidiation in Neurospora crassa (L-12)

Science.gov (United States)

Miyoshi, Yashuhiro

1993-01-01

Two fungi growth chambers containing six growth tubes each are used in this experiment. One chamber is for the space experiment; the other is for the simultaneous ground control experiment. The hyphae of Neurospora crassa band A mutant are inoculated at one end of each tube. Both the chambers are kept at 3 C plus or minus 1.5 C to stop hyphae growth until the Spacelab is activated. After the activation, each chamber is transferred simultaneously to the Spacelab and a phytotron in KSC and kept in continuous light at the same temperature. After about 24 hours of light exposure, each chamber is inserted into a growth chamber bag to keep it in constant darkness. The circadian rhythm of conidiation is initiated by this light to dark transition. After the dark incubation for 5 days at room temperature, both the growth chambers are kept at 3 C plus or minus 1.5 C to stop growth of the hyphae. After the space shuttle lands, both conidiation patterns are compared and analyzed. It has been known that numerous physiological phenomena show circadian rhythms. They are characterized by the fact that the oscillation can persist under constant conditions of light and temperature. Therefore, it has been accepted by most investigators that the generation mechanism of the circadian rhythm is endogeneous. However, one cannot reject the possibility that these rhythms are caused by some geophysical exogeneous factor having a 24-hour period, such as atmospheric pressure, gravity, or electromagnetic radiation. We use Neurospora crassa band A mutual which shows an obvious circadian rhythm in its spore-forming (conidiation) on the ground, and we intend to attempt the conidation of this mutant in the Spacelab where 24-hour periodicity is severely attenuated and to elucidate the effect of the geophysical exogeneous factor in the generation mechanism of the circadian rhythm.

Host-virus interactions of mammalian endogenous retroviruses

OpenAIRE

Farkašová, Helena

2017-01-01

Endogenous retroviruses (ERVs) originate by germline infection and subsequent mendelian inheritance of their exogenous counterparts. With notable exceptions, all mammalian ERVs are evolutionarily old and fixed in the population of its host species. Some groups of retroviruses were believed not to be able to form endogenous copies. We discovered an additional endogenous Lentivirus and a first endogenous Deltaretrovirus. Both of these groups were previously considered unable to form endogenous ...

Endogenous retroviruses function as species-specific enhancer elements in the placenta.

Science.gov (United States)

Chuong, Edward B; Rumi, M A Karim; Soares, Michael J; Baker, Julie C

2013-03-01

The mammalian placenta is remarkably distinct between species, suggesting a history of rapid evolutionary diversification. To gain insight into the molecular drivers of placental evolution, we compared biochemically predicted enhancers in mouse and rat trophoblast stem cells (TSCs) and found that species-specific enhancers are highly enriched for endogenous retroviruses (ERVs) on a genome-wide level. One of these ERV families, RLTR13D5, contributes hundreds of mouse-specific histone H3 lysine 4 monomethylation (H3K4me1)- and histone H3 lysine 27 acetylation (H3K27ac)-defined enhancers that functionally bind Cdx2, Eomes and Elf5-core factors that define the TSC regulatory network. Furthermore, we show that RLTR13D5 is capable of driving gene expression in rat placental cells. Analysis in other tissues shows that species-specific ERV enhancer activity is generally restricted to hypomethylated tissues, suggesting that tissues permissive for ERV activity gain access to an otherwise silenced source of regulatory variation. Overall, our results implicate ERV enhancer co-option as a mechanism underlying the extensive evolutionary diversification of placental development.

Endogenous rhythm and pattern-generating circuit interactions in cockroach motor centres

Directory of Open Access Journals (Sweden)

Izhak David

2016-09-01

Full Text Available Cockroaches are rapid and stable runners whose gaits emerge from the intricate, and not fully resolved, interplay between endogenous oscillatory pattern-generating networks and sensory feedback that shapes their rhythmic output. Here we studied the endogenous motor output of a brainless, deafferented preparation. We monitored the pilocarpine-induced rhythmic activity of levator and depressor motor neurons in the mesothoracic and metathoracic segments in order to reveal the oscillatory networks’ architecture and interactions. Data analyses included phase relations, latencies between and overlaps of rhythmic bursts, spike frequencies, and the dependence of these parameters on cycle frequency. We found that, overall, ipsilateral connections are stronger than contralateral ones. Our findings revealed asymmetries in connectivity among the different ganglia, in which meta-to-mesothoracic ascending coupling is stronger than meso-to-metathoracic descending coupling. Within-ganglion coupling between the metathoracic hemiganglia is stronger than that in the mesothoracic ganglion. We also report differences in the role and mode of operation of homologue network units (manifested by levator and depressor nerve activity. Many observed characteristics are similar to those exhibited by intact animals, suggesting a dominant role for feedforward control in cockroach locomotion. Based on these data we posit a connectivity scheme among components of the locomotion pattern generating system.

Circadian Rhythm Neuropeptides in Drosophila: Signals for Normal Circadian Function and Circadian Neurodegenerative Disease.

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He, Qiankun; Wu, Binbin; Price, Jeffrey L; Zhao, Zhangwu

2017-04-21

Circadian rhythm is a ubiquitous phenomenon in many organisms ranging from prokaryotes to eukaryotes. During more than four decades, the intrinsic and exogenous regulations of circadian rhythm have been studied. This review summarizes the core endogenous oscillation in Drosophila and then focuses on the neuropeptides, neurotransmitters and hormones that mediate its outputs and integration in Drosophila and the links between several of these (pigment dispersing factor (PDF) and insulin-like peptides) and neurodegenerative disease. These signaling molecules convey important network connectivity and signaling information for normal circadian function, but PDF and insulin-like peptides can also convey signals that lead to apoptosis, enhanced neurodegeneration and cognitive decline in flies carrying circadian mutations or in a senescent state.

Timing Matters: Circadian Rhythm in Sepsis, Obstructive Lung Disease, Obstructive Sleep Apnea, and Cancer.

Science.gov (United States)

Truong, Kimberly K; Lam, Michael T; Grandner, Michael A; Sassoon, Catherine S; Malhotra, Atul

2016-07-01

Physiological and cellular functions operate in a 24-hour cyclical pattern orchestrated by an endogenous process known as the circadian rhythm. Circadian rhythms represent intrinsic oscillations of biological functions that allow for adaptation to cyclic environmental changes. Key clock genes that affect the persistence and periodicity of circadian rhythms include BMAL1/CLOCK, Period 1, Period 2, and Cryptochrome. Remarkable progress has been made in our understanding of circadian rhythms and their role in common medical conditions. A critical review of the literature supports the association between circadian misalignment and adverse health consequences in sepsis, obstructive lung disease, obstructive sleep apnea, and malignancy. Circadian misalignment plays an important role in these disease processes and can affect disease severity, treatment response, and survivorship. Normal inflammatory response to acute infections, airway resistance, upper airway collapsibility, and mitosis regulation follows a robust circadian pattern. Disruption of normal circadian rhythm at the molecular level affects severity of inflammation in sepsis, contributes to inflammatory responses in obstructive lung diseases, affects apnea length in obstructive sleep apnea, and increases risk for cancer. Chronotherapy is an underused practice of delivering therapy at optimal times to maximize efficacy and minimize toxicity. This approach has been shown to be advantageous in asthma and cancer management. In asthma, appropriate timing of medication administration improves treatment effectiveness. Properly timed chemotherapy may reduce treatment toxicities and maximize efficacy. Future research should focus on circadian rhythm disorders, role of circadian rhythm in other diseases, and modalities to restore and prevent circadian disruption.

Dim Light at Night Disrupts Molecular Circadian Rhythms and Affects Metabolism

Science.gov (United States)

Fonken, Laura K.; Aubrecht, Taryn G.; Meléndez-Fernández, O. Hecmarie; Weil, Zachary M.; Nelson, Randy J.

2014-01-01

With the exception of high latitudes, life has evolved under bright days and dark nights. Most organisms have developed endogenously driven circadian rhythms which are synchronized to this daily light/dark cycle. In recent years, humans have shifted away from the naturally occurring solar light cycle in favor of artificial and sometimes irregular light schedules produced by electrical lighting. Exposure to unnatural light cycles is increasingly associated with obesity and metabolic syndrome; however the means by which environmental lighting alters metabolism are poorly understood. Thus, we exposed mice to nighttime light and investigated changes in the circadian system and body weight. Here we report that exposure to ecologically relevant levels of dim (5 lux) light at night attenuate core circadian clock rhythms in the SCN at both the gene and protein level. Moreover, circadian clock rhythms were perturbed in the liver by nighttime light exposure. Changes in the circadian clock were associated with temporal alterations in feeding behavior and increased weight gain. These results are significant because they provide mechanistic evidence for how mild changes in environmental lighting can alter circadian and metabolic function. PMID:23929553

Circadian rhythm phase shifts and endogenous free-running circadian period differ between African-Americans and European-Americans.

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Eastman, Charmane I; Suh, Christina; Tomaka, Victoria A; Crowley, Stephanie J

2015-02-11

Successful adaptation to modern civilization requires the internal circadian clock to make large phase shifts in response to circumstances (e.g., jet travel and shift work) that were not encountered during most of our evolution. We found that the magnitude and direction of the circadian clock's phase shift after the light/dark and sleep/wake/meal schedule was phase-advanced (made earlier) by 9 hours differed in European-Americans compared to African-Americans. European-Americans had larger phase shifts, but were more likely to phase-delay after the 9-hour advance (to phase shift in the wrong direction). The magnitude and direction of the phase shift was related to the free-running circadian period, and European-Americans had a longer circadian period than African-Americans. Circadian period was related to the percent Sub-Saharan African and European ancestry from DNA samples. We speculate that a short circadian period was advantageous during our evolution in Africa and lengthened with northern migrations out of Africa. The differences in circadian rhythms remaining today are relevant for understanding and treating the modern circadian-rhythm-based disorders which are due to a misalignment between the internal circadian rhythms and the times for sleep, work, school and meals.

Circadian Rhythms in Cyanobacteria

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Golden, Susan S.

2015-01-01

SUMMARY Life on earth is subject to daily and predictable fluctuations in light intensity, temperature, and humidity created by rotation of the earth. Circadian rhythms, generated by a circadian clock, control temporal programs of cellular physiology to facilitate adaptation to daily environmental changes. Circadian rhythms are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Here we introduce the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942. We review the current understanding of the cyanobacterial clock, emphasizing recent work that has generated a more comprehensive understanding of how the circadian oscillator becomes synchronized with the external environment and how information from the oscillator is transmitted to generate rhythms of biological activity. These results have changed how we think about the clock, shifting away from a linear model to one in which the clock is viewed as an interactive network of multifunctional components that are integrated into the context of the cell in order to pace and reset the oscillator. We conclude with a discussion of how this basic timekeeping mechanism differs in other cyanobacterial species and how information gleaned from work in cyanobacteria can be translated to understanding rhythmic phenomena in other prokaryotic systems. PMID:26335718

Maternal circadian rhythms and the programming of adult health and disease.

Science.gov (United States)

Varcoe, Tamara J; Gatford, Kathryn L; Kennaway, David J

2018-02-01

The in utero environment is inherently rhythmic, with the fetus subjected to circadian changes in temperature, substrates, and various maternal hormones. Meanwhile, the fetus is developing an endogenous circadian timing system, preparing for life in an external environment where light, food availability, and other environmental factors change predictably and repeatedly every 24 h. In humans, there are many situations that can disrupt circadian rhythms, including shift work, international travel, insomnias, and circadian rhythm disorders (e.g., advanced/delayed sleep phase disorder), with a growing consensus that this chronodisruption can have deleterious consequences for an individual's health and well-being. However, the impact of chronodisruption during pregnancy on the health of both the mother and fetus is not well understood. In this review, we outline circadian timing system ontogeny in mammals and examine emerging research from animal models demonstrating long-term negative implications for progeny health following maternal chronodisruption during pregnancy.

Circadian melatonin rhythm and excessive daytime sleepiness in Parkinson disease.

Science.gov (United States)

Videnovic, Aleksandar; Noble, Charleston; Reid, Kathryn J; Peng, Jie; Turek, Fred W; Marconi, Angelica; Rademaker, Alfred W; Simuni, Tanya; Zadikoff, Cindy; Zee, Phyllis C

2014-04-01

Diurnal fluctuations of motor and nonmotor symptoms and a high prevalence of sleep-wake disturbances in Parkinson disease (PD) suggest a role of the circadian system in the modulation of these symptoms. However, surprisingly little is known regarding circadian function in PD and whether circadian dysfunction is involved in the development of sleep-wake disturbances in PD. To determine the relationship between the timing and amplitude of the 24-hour melatonin rhythm, a marker of endogenous circadian rhythmicity, with self-reported sleep quality, the severity of daytime sleepiness, and disease metrics. A cross-sectional study from January 1, 2009, through December 31, 2012, of 20 patients with PD receiving stable dopaminergic therapy and 15 age-matched control participants. Both groups underwent blood sampling for the measurement of serum melatonin levels at 30-minute intervals for 24 hours under modified constant routine conditions at the Parkinson's Disease and Movement Disorders Center of Northwestern University. Twenty-four hour monitoring of serum melatonin secretion. Clinical and demographic data, self-reported measures of sleep quality (Pittsburgh Sleep Quality Index) and daytime sleepiness (Epworth Sleepiness Scale), and circadian markers of the melatonin rhythm, including the amplitude, area under the curve (AUC), and phase of the 24-hour rhythm. Patients with PD had blunted circadian rhythms of melatonin secretion compared with controls; the amplitude of the melatonin rhythm and the 24-hour AUC for circulating melatonin levels were significantly lower in PD patients (P hour melatonin AUC (P = .001). Disease duration, Unified Parkinson's Disease Rating Scale scores, levodopa equivalent dose, and global Pittsburgh Sleep Quality Index score in the PD group were not significantly related to measures of the melatonin circadian rhythm. Circadian dysfunction may underlie excessive sleepiness in PD. The nature of this association needs to be explored further

Markets, Bodies, Rhythms

DEFF Research Database (Denmark)

Borch, Christian; Bondo Hansen, Kristian; Lange, Ann-Christina

2015-01-01

to respond to a widely perceived problem, namely that market rhythms might be contagious and that some form of separation of bodily and market rhythms might therefore be needed. Finally, we show how current high-frequency trading, despite being purely algorithmic, does not render the traders' bodies......This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre......'s rhythmanalysis, we show how traders seek to calibrate their bodily rhythms to those of the market. We argue that, in the case of early-20th-century open-outcry trading pits, traders tried to enact a total merger of bodily and market rhythms. We also demonstrate how, in the 1920s and '30s, market observers began...

Evaluation of endogenous species involved in brain tumors using multiphoton photoacoustic spectroscopy

Science.gov (United States)

Dahal, Sudhir; Cullum, Brian M.

2013-05-01

It has been shown that using non-resonant multiphoton photoacoustic spectroscopy (NMPPAS), excised brain tumor (grade III astrocytoma) and healthy tissue can be differentiated from each other, even in neighboring biopsy samples[1, 2]. Because of this, this powerful technique offers a great deal of potential for use as a surgical guidance technique for tumor margining with up to cellular level spatial resolution[3]. NMPPAS spectra are obtained by monitoring the non-radiative relaxation pathways via ultrasonic detection, following two-photon excitation with light in the optical diagnostic window (740nm-1100nm). Based upon significant differences in the ratiometric absorption of the tissues following 970nm and 1100nm excitation, a clear classification of the tissue can be made. These differences are the result of variations in composition and oxidation state of certain endogenous biochemical species between healthy and malignant tissues. In this work, NADH, NAD+ and ATP were measured using NMPPAS in model gelatin tissue phantoms to begin to understand which species might be responsible for the observed spectral differences in the tissue. Each species was placed in specific pH environments to provide control over the ratio of oxidized to reduced forms of the species. Ratiometric analyses were then conducted to account for variability caused due to instrumental parameters. This paper will discuss the potential roles of each of the species for tumor determination and their contribution to the spectral signature.

Circadian rhythm and its role in malignancy

Directory of Open Access Journals (Sweden)

Mahmood Saqib

2010-03-01

Full Text Available Abstract Circadian rhythms are daily oscillations of multiple biological processes directed by endogenous clocks. The circadian timing system comprises peripheral oscillators located in most tissues of the body and a central pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus. Circadian genes and the proteins produced by these genes constitute the molecular components of the circadian oscillator which form positive/negative feedback loops and generate circadian rhythms. The circadian regulation extends beyond clock genes to involve various clock-controlled genes (CCGs including various cell cycle genes. Aberrant expression of circadian clock genes could have important consequences on the transactivation of downstream targets that control the cell cycle and on the ability of cells to undergo apoptosis. This may lead to genomic instability and accelerated cellular proliferation potentially promoting carcinogenesis. Different lines of evidence in mice and humans suggest that cancer may be a circadian-related disorder. The genetic or functional disruption of the molecular circadian clock has been found in various cancers including breast, ovarian, endometrial, prostate and hematological cancers. The acquisition of current data in circadian clock mechanism may help chronotherapy, which takes into consideration the biological time to improve treatments by devising new therapeutic approaches for treating circadian-related disorders, especially cancer.

Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

Energy Technology Data Exchange (ETDEWEB)

Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min [Center for Biosignals, Korea Research Institute of Standards and Science(KRISS), Daejeon (Korea, Republic of)

2015-12-15

Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively.

Measurement of the occipital alpha rhythm and temporal tau rhythm by using magnetoencephalography

International Nuclear Information System (INIS)

Kim, J. E.; Gohel, Bakul; Kim, K.; Kwon, H.; An, Kyung Min

2015-01-01

Developing Magnetoencephalography (MEG) based on Superconducting Quantum Interference Device (SQUID) facilitates to observe the human brain functions in non-invasively and high temporal and high spatial resolution. By using this MEG, we studied alpha rhythm (8-13 Hz) that is one of the most predominant spontaneous rhythm in human brain. The 8–13 Hz rhythm is observed in several sensory region in the brain. In visual related region of occipital, we call to alpha rhythm, and auditory related region of temporal call to tau rhythm, sensorimotor related region of parietal call to mu rhythm. These rhythms are decreased in task related region and increased in task irrelevant regions. This means that these rhythms play a pivotal role of inhibition in task irrelevant region. It may be helpful to attention to the task. In several literature about the alpha-band inhibition in multi-sensory modality experiment, they observed this effect in the occipital and somatosensory region. In this study, we hypothesized that we can also observe the alpha-band inhibition in the auditory cortex, mediated by the tau rhythm. Before that, we first investigated the existence of the alpha and tau rhythm in occipital and temporal region, respectively. To see these rhythms, we applied the visual and auditory stimulation, in turns, suppressed in task relevant regions, respectively

The Paradox of Isochrony in the Evolution of Human Rhythm

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Andrea Ravignani

2017-11-01

Full Text Available Isochrony is crucial to the rhythm of human music. Some neural, behavioral and anatomical traits underlying rhythm perception and production are shared with a broad range of species. These may either have a common evolutionary origin, or have evolved into similar traits under different evolutionary pressures. Other traits underlying rhythm are rare across species, only found in humans and few other animals. Isochrony, or stable periodicity, is common to most human music, but isochronous behaviors are also found in many species. It appears paradoxical that humans are particularly good at producing and perceiving isochronous patterns, although this ability does not conceivably confer any evolutionary advantage to modern humans. This article will attempt to solve this conundrum. To this end, we define the concept of isochrony from the present functional perspective of physiology, cognitive neuroscience, signal processing, and interactive behavior, and review available evidence on isochrony in the signals of humans and other animals. We then attempt to resolve the paradox of isochrony by expanding an evolutionary hypothesis about the function that isochronous behavior may have had in early hominids. Finally, we propose avenues for empirical research to examine this hypothesis and to understand the evolutionary origin of isochrony in general.

Evolutionary dynamics of endogenous feline leukemia virus proliferation among species of the domestic cat lineage

International Nuclear Information System (INIS)

Polani, Sagi; Roca, Alfred L.; Rosensteel, Bryan B.; Kolokotronis, Sergios-Orestis; Bar-Gal, Gila Kahila

2010-01-01

Endogenous feline leukemia viruses (enFeLVs) occur in the germ lines of the domestic cat and related wild species (genus Felis). We sequenced the long terminal repeats and part of the env region of enFeLVs in domestic cats and five wild species. A total of 305 enFeLV sequences were generated across 17 individuals, demonstrating considerable diversity within two major clades. Distinct proliferations of enFeLVs occurred before and after the black-footed cat diverged from the other species. Diversity of enFeLVs was limited for the sand cat and jungle cat suggesting that proliferation of enFeLVs occurred within these species after they diverged. Relationships among enFeLVs were congruent with host species relationships except for the jungle cat, which carried only enFeLVs from a lineage that recently invaded the germline (enFeLV-AGTT). Comparison of wildcat and domestic cat enFeLVs indicated that a distinctive germ line invasion of enFeLVs has not occurred since the cat was domesticated.

Burying behaviour of two sympatric crab species: Cancer magister and Cancer productus

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Iain J. McGaw

2005-09-01

Full Text Available The mechanics and emergence patterns associated with burying behaviour were investigated in the Dungeness crab, Cancer magister, and the red rock crab, Cancer productus. Cancer magister used both the legs and chelae to excavate the sand, whereas Cancer productus used the legs to pull and push itself down into the sediment only using the chelae in a final push beneath the sediment. Several individuals of each species remained buried for over 50 h, which was accomplished by alterations in ventilatory physiology. More commonly, both species exhibited an endogenous rhythm of circadian periodicity, with peak periods of emergence from the sand occurring during nocturnal high tides. Although burial may act as a means of predator evasion and to ambush prey, it appears the primary reason may be to conserve energy. These two species of crabs often occur sympatrically; the difference in behaviours is closely related to previously reported differences in physiological mechanisms between the two species when buried.

Circadian melatonin concentration rhythm is lost in pregnant women with altered blood pressure rhythm.

Science.gov (United States)

Tranquilli, A L; Turi, A; Giannubilo, S R; Garbati, E

2004-03-01

We assessed the correlation between the rhythm of melatonin concentration and circadian blood pressure patterns in normal and hypertensive pregnancy. Ambulatory 24-h blood pressure and blood samples every 4 h were monitored in 16 primigravidae who had shown an abnormal circadian blood pressure pattern (eight pre-eclamptic and eight normotensive) in pregnancy and 6-12 months after pregnancy. The circadian rhythm was analyzed by chronobiological measures. Eight normotensive women with maintained blood pressure rhythm served as controls. During pregnancy, melatonin concentration was significantly higher in pre-eclamptic than in normotensive women (pre-eclampsia, 29.4 +/- 1.9 pg/ml, normotensin, altered rhythm, 15.6 +/- 2.1; controls, 22.7 +/- 1.8; p lost in all pregnant women with loss of blood pressure rhythm. After pregnancy, normotensive women showed a reappearance of both melatonin and blood pressure rhythm, whereas pre-eclamptic women showed a reappearance of blood pressure but not melatonin rhythm. The loss of blood pressure rhythm in pregnancy is consistent with the loss of melatonin concentration rhythm. In pre-eclamptic women, the normalization of blood pressure rhythm, while melatonin rhythm remained altered, suggests a temporal or causal priority of circadian concentration of melatonin in the determination of blood pressure trend.

The human endogenous circadian system causes greatest platelet activation during the biological morning independent of behaviors.

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Frank A J L Scheer

Full Text Available Platelets are involved in the thromboses that are central to myocardial infarctions and ischemic strokes. Such adverse cardiovascular events have day/night patterns with peaks in the morning (~9 AM, potentially related to endogenous circadian clock control of platelet activation. The objective was to test if the human endogenous circadian system influences (1 platelet function and (2 platelet response to standardized behavioral stressors. We also aimed to compare the magnitude of any effects on platelet function caused by the circadian system with that caused by varied standardized behavioral stressors, including mental arithmetic, passive postural tilt and mild cycling exercise.We studied 12 healthy adults (6 female who lived in individual laboratory suites in dim light for 240 h, with all behaviors scheduled on a 20-h recurring cycle to permit assessment of endogenous circadian function independent from environmental and behavioral effects including the sleep/wake cycle. Circadian phase was assessed from core body temperature. There were highly significant endogenous circadian rhythms in platelet surface activated glycoprotein (GP IIb-IIIa, GPIb and P-selectin (6-17% peak-trough amplitudes; p ≤ 0.01. These circadian peaks occurred at a circadian phase corresponding to 8-9 AM. Platelet count, ATP release, aggregability, and plasma epinephrine also had significant circadian rhythms but with later peaks (corresponding to 3-8 PM. The circadian effects on the platelet activation markers were always larger than that of any of the three behavioral stressors.These data demonstrate robust effects of the endogenous circadian system on platelet activation in humans--independent of the sleep/wake cycle, other behavioral influences and the environment. The 9 AM timing of the circadian peaks of the three platelet surface markers, including platelet surface activated GPIIb-IIIa, the final common pathway of platelet aggregation, suggests that endogenous

Season-dependent effects of photoperiod and temperature on circadian rhythm of arylalkylamine N-acetyltransferase2 gene expression in pineal organ of an air-breathing catfish, Clarias gariepinus.

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Singh, Kshetrimayum Manisana; Saha, Saurav; Gupta, Braj Bansh Prasad

2017-08-01

Arylalkylamine N-acetyltransferase (AANAT) activity, aanat gene expression and melatonin production have been reported to exhibit prominent circadian rhythm in the pineal organ of most species of fish. Three types of aanat genes are expressed in fish, but the fish pineal organ predominantly expresses aanat2 gene. Increase and decrease in daylength is invariably associated with increase and decrease in temperature, respectively. But so far no attempt has been made to delineate the role of photoperiod and temperature in regulation of the circadian rhythm of aanat2 gene expression in the pineal organ of any fish with special reference to seasons. Therefore, we studied effects of various lighting regimes (12L-12D, 16L-8D, 8L-16D, LL and DD) at a constant temperature (25°C) and effects of different temperatures (15°, 25° and 35°C) under a common photoperiod 12L-12D on circadian rhythm of aanat2 gene expression in the pineal organ of Clarias gariepinus during summer and winter seasons. Aanat2 gene expression in fish pineal organ was studied by measuring aanat2 mRNA levels using Real-Time PCR. Our findings indicate that the pineal organ of C. gariepinus exhibits a prominent circadian rhythm of aanat2 gene expression irrespective of photoperiods, temperatures and seasons, and the circadian rhythm of aanat2 gene expression responds differently to different photoperiods and temperatures in a season-dependent manner. Existence of circadian rhythm of aanat2 gene expression in pineal organs maintained in vitro under 12L-12D and DD conditions as well as a free running rhythm of the gene expression in pineal organ of the fish maintained under LL and DD conditions suggest that the fish pineal organ possesses an endogenous circadian oscillator, which is entrained by light-dark cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression and function of endogenous retroviruses in the placenta.

Science.gov (United States)

Denner, Joachim

2016-01-01

Although the expression of endogenous retroviruses in the placenta of numerous species was observed a long time ago, their physiological function during gestation was demonstrated only very recently. Expression of retroviral envelope proteins, also called syncytins, in the placenta allows generation of the multinuclear syncytiotrophoblast as an outer cellular layer of the placenta by fusion of the trophoblast cells. This fusion process is crucial for the development of the placenta and for successful pregnancy. It is still unclear whether the immunosuppressive properties of the transmembrane envelope protein of the endogenous retroviruses expressed in the placenta contribute to immunosuppression to prevent the rejection of the semiallotransplant embryo. The presence of placenta cells expressing retroviral envelope proteins surrounded by immune cells deep in the maternal tissue supports an immunosuppressive function. It is important to emphasize that during evolution different species utilized ('enslaved') different endogenous retroviruses and that two or more endogenous retroviruses are involved in placentogenesis in each species. © 2016 APMIS. Published by John Wiley & Sons Ltd.

RHYTHM STRUCTURE IN NEWS READING

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Lluís Mas Manchón

2013-06-01

Full Text Available Rhythm is central to news reading in radio and television programs. This paper proposes a three level structure for rhythm in news discourse. It gives a comprehensive definition of rhythm and types of rhythm. Firstly, the Base Rhythm Structure consists of semantic and pragmatic rhythmic accents, coincident with very specific words. Secondly, these accents are grouped together according to type, frequency and order, thereby configuring three types of “rhythmic units” (the Internal Rhythm Structure: starting, main and end units. A last structure level presents four discursive factors that are very important in integrating the overall time structure of news announcing (the Melodic Rhythm Structure. This integral structure for news announcing rhythm should be further tested in acoustic-experimental studies under the criterion of information transmission efficacy.

Dim light at night disrupts molecular circadian rhythms and increases body weight.

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Fonken, Laura K; Aubrecht, Taryn G; Meléndez-Fernández, O Hecmarie; Weil, Zachary M; Nelson, Randy J

2013-08-01

With the exception of high latitudes, life has evolved under bright days and dark nights. Most organisms have developed endogenously driven circadian rhythms that are synchronized to this daily light/dark cycle. In recent years, humans have shifted away from the naturally occurring solar light cycle in favor of artificial and sometimes irregular light schedules produced by electric lighting. Exposure to unnatural light cycles is increasingly associated with obesity and metabolic syndrome; however, the means by which environmental lighting alters metabolism are poorly understood. Thus, we exposed mice to dim light at night and investigated changes in the circadian system and metabolism. Here we report that exposure to ecologically relevant levels of dim (5 lux) light at night altered core circadian clock rhythms in the hypothalamus at both the gene and protein level. Circadian rhythms in clock expression persisted during light at night; however, the amplitude of Per1 and Per2 rhythms was attenuated in the hypothalamus. Circadian oscillations were also altered in peripheral tissues critical for metabolic regulation. Exposure to dimly illuminated, as compared to dark, nights decreased the rhythmic expression in all but one of the core circadian clock genes assessed in the liver. Additionally, mice exposed to dim light at night attenuated Rev-Erb expression in the liver and adipose tissue. Changes in the circadian clock were associated with temporal alterations in feeding behavior and increased weight gain. These results are significant because they provide evidence that mild changes in environmental lighting can alter circadian and metabolic function. Detailed analysis of temporal changes induced by nighttime light exposure may provide insight into the onset and progression of obesity and metabolic syndrome, as well as other disorders involving sleep and circadian rhythm disruption.

Rhythm in language acquisition.

Science.gov (United States)

Langus, Alan; Mehler, Jacques; Nespor, Marina

2017-10-01

Spoken language is governed by rhythm. Linguistic rhythm is hierarchical and the rhythmic hierarchy partially mimics the prosodic as well as the morpho-syntactic hierarchy of spoken language. It can thus provide learners with cues about the structure of the language they are acquiring. We identify three universal levels of linguistic rhythm - the segmental level, the level of the metrical feet and the phonological phrase level - and discuss why primary lexical stress is not rhythmic. We survey experimental evidence on rhythm perception in young infants and native speakers of various languages to determine the properties of linguistic rhythm that are present at birth, those that mature during the first year of life and those that are shaped by the linguistic environment of language learners. We conclude with a discussion of the major gaps in current knowledge on linguistic rhythm and highlight areas of interest for future research that are most likely to yield significant insights into the nature, the perception, and the usefulness of linguistic rhythm. Copyright © 2016 Elsevier Ltd. All rights reserved.

Circadian Rhythms

Indian Academy of Sciences (India)

IAS Admin

thus appear to be simple responses of living beings to cyclic presence/absence of ... For example, during leaf movement rhythms, leaves alternate between open and closed states .... gist of his time, in an elegant experiment (Box 2) to study the navigational .... diurnal rhythms as true biological timekeepers, a question which.

An Approximation to the Temporal Order in Endogenous Circadian Rhythms of Genes Implicated in Human Adipose Tissue Metabolism

Science.gov (United States)

GARAULET, MARTA; ORDOVÁS, JOSÉ M.; GÓMEZ-ABELLÁN, PURIFICACIÓN; MARTÍNEZ, JOSE A.; MADRID, JUAN A.

2015-01-01

Although it is well established that human adipose tissue (AT) shows circadian rhythmicity, published studies have been discussed as if tissues or systems showed only one or few circadian rhythms at a time. To provide an overall view of the internal temporal order of circadian rhythms in human AT including genes implicated in metabolic processes such as energy intake and expenditure, insulin resistance, adipocyte differentiation, dyslipidemia, and body fat distribution. Visceral and subcutaneous abdominal AT biopsies (n = 6) were obtained from morbid obese women (BMI ≥ 40 kg/m2). To investigate rhythmic expression pattern, AT explants were cultured during 24-h and gene expression was analyzed at the following times: 08:00, 14:00, 20:00, 02:00 h using quantitative real-time PCR. Clock genes, glucocorticoid metabolism-related genes, leptin, adiponectin and their receptors were studied. Significant differences were found both in achrophases and relative-amplitude among genes (P 30%). When interpreting the phase map of gene expression in both depots, data indicated that circadian rhythmicity of the genes studied followed a predictable physiological pattern, particularly for subcutaneous AT. Interesting are the relationships between adiponectin, leptin, and glucocorticoid metabolism-related genes circadian profiles. Their metabolic significance is discussed. Visceral AT behaved in a different way than subcutaneous for most of the genes studied. For every gene, protein mRNA levels fluctuated during the day in synchrony with its receptors. We have provided an overall view of the internal temporal order of circadian rhythms in human adipose tissue. PMID:21520059

Preliminary evidences of circadian fan activity rhythm in Sabella spallanzanii (Gmelin, 1791 (Polychaeta: Sabellidae

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Jacopo Aguzzi

2006-12-01

Full Text Available The fan activity rhythm of Sabella spallanzanii (Gmelin, 1791 and its entrainment capability to light were studied. Animals were tested under constant darkness (DD followed by two consecutive 24 h light-darkness regimes: a first 11 h light period (LD and a second 9 h light period, with its phase inverted (DL. An infrared analogical video-camera took shots each 30 s. A number of pictures with open fan were counted every 15 min. In DD a weak free-running periodicity in the circadian range was found, thus reinforcing the matching of the 24 h period under study in both photoperiod regimes. A nocturnal activity was characterised with a consistent anticipation to lightOFF (i.e. entrainment. Moreover, this phase of entrainment differed between DL and LD. The presence of endogenous activity rhythm with a variable phase angle of entrainment is a distinctive feature of circadian pacemakers.

Circadian Rhythms

Indian Academy of Sciences (India)

IAS Admin

and clocks driving such rhythms have been studied for a long time now, our ... passage of time using near 24 h oscillation as a reference process, and (iii) Output .... Bünning's work on circadian rhythms across model systems ranging from ..... E Bünning, The Physiological Clock, Revised 3rd Edition, The English. Universities ...

Visible Battle Rhythm

National Research Council Canada - National Science Library

Cort, Brian; Bouchard, Alain; Gouin, Denis; Proulx, Pascale; Wright, William

2006-01-01

.... Visual Battle Rhythm (VBR) is a software prototype which updates the battle rhythm process with modern technology and careful information design to improve the synchronization, situational awareness and decision making ability of commanders...

How Two Players Negotiate Rhythm in a Shared Rhythm Game

DEFF Research Database (Denmark)

Hansen, Anne-Marie; Andersen, Hans Jørgen; Raudaskoski, Pirkko Liisa

2012-01-01

from each other. Video analysis of user interaction shines light upon how users engaged in a rhythmical relationship, and interviews give information about the user experience in terms of the game play and user collaboration. Based on the findings in this paper we propose design guidelines......In a design and working prototype of a shared music interface eleven teams of two people were to collaborate about filling in holes with tones and beats in an evolving ground rhythm. The hypothesis was that users would tune into each other and have sections of characteristic rhythmical...... relationships that related to the ground rhythm. Results from interaction data show that teams did find a mutual rhythm, and that they were able to keep this rhythm for a while and/or over several small periods. Results also showed that two players engaged in very specific rhythmical relationships that differed...

Entrainment of the Circadian Rhythm in Egg Hatching of the Crab Dyspanopeus sayi by Chemical Cues from Ovigerous Females.

Science.gov (United States)

Forward, Richard B; Sanchez, Kevin G; Riley, Paul P

2016-02-01

The subtidal crab Dyspanopeus sayi has a circadian rhythm in larval release with a free-running period of 24.1 h. Under constant conditions, eggs hatch primarily in the 4-h interval after the time of sunset. The study tested the new model for entrainment in subtidal crabs, which proposes that the female perceives the environmental cycles and entrains the endogenous rhythm in the embryos. Results verified the model for D. sayi. Hatching by embryos collected from the field when they had not yet developed eye pigments, and were kept in constant conditions attached to their mother, exhibited the circadian hatching rhythm. Attached embryos could also be entrained to a new photoperiod in the laboratory before they developed eye pigments. Further, mature embryos removed from the female hatched rhythmically, indicating that a circadian rhythm resides in the embryos. However, if mature embryos with eye pigments were removed from the female and exposed to a new light-dark cycle, they could not be entrained to the new cycle; rather, they hatched according to the timing of the original light-dark cycle. Nevertheless, detached, mature embryos would entrain to a new light-dark cycle if they were in chemical, but not physical, contact with the female. Thus, the female perceives the light-dark cycle, and uses chemical cues to entrain the circadian rhythm of hatching by the embryos. © 2016 Marine Biological Laboratory.

Evaluation of parameters of a plankton community's biological rhythms under the natural environment of the Black Sea using the Fourier transform method.

Science.gov (United States)

Mel'nikova, Ye B

2017-05-01

Night-time changes in bioluminescence intensity in the coastal area of the Black Sea were recorded. It was noted that the biomass of luminous organisms is closely correlated with the biomass of plankton and other pelagic organisms, including commercial pelagic fish. The parameters of plankton communities' basic biological rhythms were determined using the discrete Fourier transform method. These rhythms were manifest as spatial and temporal changes in the bioluminescence intensity. It was shown that changes in the bioluminescence intensity over a 14.0-h period were due to the duration of the light/dark cycles. By contrast, changes in bioluminescence intensity with periods of 4.7 and 2.8 h were due to the endogenous rhythms of the plankton community (feeding and cell division). An original method for evaluating of errors in the calculated periods of the biological rhythms was proposed. A strong correlation (r = 0.906) was observed between the measured and calculated values for the bioluminescence intensity, which provided support for the assumptions made. Copyright © 2016 John Wiley & Sons, Ltd.

Temperature compensation and entrainment in circadian rhythms

International Nuclear Information System (INIS)

Bodenstein, C; Heiland, I; Schuster, S

2012-01-01

To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles. (paper)

Circadian Rhythms, Sleep Deprivation, and Human Performance

Science.gov (United States)

Goel, Namni; Basner, Mathias; Rao, Hengyi; Dinges, David F.

2014-01-01

Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep–wake regulation, which posits a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed. PMID:23899598

PPARα is a potential therapeutic target of drugs to treat circadian rhythm sleep disorders

International Nuclear Information System (INIS)

Shirai, Hidenori; Oishi, Katsutaka; Kudo, Takashi; Shibata, Shigenobu; Ishida, Norio

2007-01-01

Recent progress at the molecular level has revealed that nuclear receptors play an important role in the generation of mammalian circadian rhythms. To examine whether peroxisome proliferator-activated receptor alpha (PPARα) is involved in the regulation of circadian behavioral rhythms in mammals, we evaluated the locomotor activity of mice administered with the hypolipidemic PPARα ligand, bezafibrate. Circadian locomotor activity was phase-advanced about 3 h in mice given bezafibrate under light-dark (LD) conditions. Transfer from LD to constant darkness did not change the onset of activity in these mice, suggesting that bezafibrate advanced the phase of the endogenous clock. Surprisingly, bezafibrate also advanced the phase in mice with lesions of the suprachiasmatic nucleus (SCN; the central clock in mammals). The circadian expression of clock genes such as period2, BMAL1, and Rev-erbα was also phase-advanced in various tissues (cortex, liver, and fat) without affecting the SCN. Bezafibrate also phase-advanced the activity phase that is delayed in model mice with delayed sleep phase syndrome (DSPS) due to a Clock gene mutation. Our results indicated that PPARα is involved in circadian clock control independently of the SCN and that PPARα could be a potent target of drugs to treat circadian rhythm sleep disorders including DSPS

Novel non-indolic melatonin receptor agonists differentially entrain endogenous melatonin rhythm and increase its amplitude

NARCIS (Netherlands)

Drijfhout, W.J; de Vries, J.B; Homan, E.J; Brons, H.F; Copinga, S; Gruppen, G; Beresford, I.J M; Hagan, R.M; Grol, Cor; Westerink, B.H.C.

1999-01-01

In this study we have examined the ability of melatonin and four synthetic melatonin receptor agonists to entrain endogenous melatonin secretion in rats, free running in constant darkness. The circadian melatonin profile was measured by trans-pineal microdialysis, which not only reveals the time of

Circadian Rhythm Shapes the Gut Microbiota Affecting Host Radiosensitivity.

Science.gov (United States)

Cui, Ming; Xiao, Huiwen; Luo, Dan; Zhang, Xin; Zhao, Shuyi; Zheng, Qisheng; Li, Yuan; Zhao, Yu; Dong, Jiali; Li, Hang; Wang, Haichao; Fan, Saijun

2016-10-26

Modern lifestyles, such as shift work, nocturnal social activities, and jet lag, disturb the circadian rhythm. The interaction between mammals and the co-evolved intestinal microbiota modulates host physiopathological processes. Radiotherapy is a cornerstone of modern management of malignancies; however, it was previously unknown whether circadian rhythm disorder impairs prognosis after radiotherapy. To investigate the effect of circadian rhythm on radiotherapy, C57BL/6 mice were housed in different dark/light cycles, and their intestinal bacterial compositions were compared using high throughput sequencing. The survival rate, body weight, and food intake of mice in diverse cohorts were measured following irradiation exposure. Finally, the enteric bacterial composition of irradiated mice that experienced different dark/light cycles was assessed using 16S RNA sequencing. Intriguingly, mice housed in aberrant light cycles harbored a reduction of observed intestinal bacterial species and shifts of gut bacterial composition compared with those of the mice kept under 12 h dark/12 h light cycles, resulting in a decrease of host radioresistance. Moreover, the alteration of enteric bacterial composition of mice in different groups was dissimilar. Our findings provide novel insights into the effects of biological clocks on the gut bacterial composition, and underpin that the circadian rhythm influences the prognosis of patients after radiotherapy in a preclinical setting.

Rhythm and Time in Music Epitomize the Temporal Dynamics of Human Communicative Behavior: The Broad Implications of London's Trinity

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Peter E. Keller

2012-09-01

Full Text Available Three key issues about rhythm and timing in music are drawn to the attention of linguists in a paper by London (2012. In this commentary, I argue that these issues are relevant not only to linguists, but also to those in any field dealing with the temporal dynamics of human communicative behavior. Thus, the distinction between endogenously and exogenously driven mechanisms of perceptual organization, the active nature of perception, and the presence of multiple time scales are topics that also concern experimental psychologists and cognitive neuroscientists. London’s argument that these three issues play a crucial role in the perception of rhythm and timing implies that they should be considered collectively when attempting to understand diverse communicative acts.

Human biological rhythm in traditional Chinese medicine

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Tianxing Zhang

2016-10-01

Full Text Available Traditional Chinese medicine (TCM has a comprehensive and thorough understanding of biological rhythm. Biological rhythm is an inherent connotation of “harmony between human and nature”, one of the thoughts in TCM. TCM discusses emphatically circadian rhythm, syzygial rhythm and seasonal rhythm, and particularly circadian and seasonal rhythms. Theories of Yin Yang and Five Elements are the principles and methods, with which TCM understands biological rhythms. Based on theories in TCM, biological rhythm in essence is a continuous variation of the human body state synchronized with natural rhythms, and theories of Yin Yang and Five Elements are both language tools to describe this continuous variation and theoretical tools for its investigation and application. The understandings of biological rhythm in TCM can be applied to etiology, health care, disease control and treatment. Many understandings in TCM have been confirmed by modern research and clinical reports, but there are still some pending issues. TCM is distinguished for its holistic viewpoint on biological rhythms.

Sympathetic rhythms and nervous integration.

Science.gov (United States)

Gilbey, Michael P

2007-04-01

1. The present review focuses on some of the processes producing rhythms in sympathetic nerves influencing cardiovascular functions and considers their potential relevance to nervous integration. 2. Two mechanisms are considered that may account for rhythmic sympathetic discharges. First, neuronal elements of peripheral or central origin produce rhythmic activity by phasically exciting and/or inhibiting neurons within central sympathetic networks. Second, rhythms arise within central sympathetic networks. Evidence is considered that indicates the operation of both mechanisms; the first in muscle and the second in skin sympathetic vasoconstrictor networks. 3. Sympathetic activity to the rat tail, a model for the nervous control of skin circulation, is regulated by central networks involved in thermoregulation and those associated with fear and arousal. In an anaesthetized preparation, activity displays an apparently autonomous rhythm (T-rhythm; 0.4-1.2 Hz) and the level of activity can be manipulated by regulating core body temperature. This model has been used to study rhythm generation in central sympathetic networks and possible functional relevance. 4. A unique insight provided by the T rhythm, into possible physiological function(s) underlying rhythmic sympathetic discharges is that the activity of single sympathetic post-ganglionic neurons within a population innervating the same target can have different rhythm frequencies. Therefore, the graded and dynamic entrainment of the rhythms by inputs, such as central respiratory drive and/or lung inflation-related afferent activity, can produce graded and dynamic synchronization of sympathetic discharges. The degree of synchronization may influence the efficacy of transmission in a target chain of excitable cells. 5. The T-rhythm may be generated within the spinal cord because the intrathecal application of 5-hydroxytryptamine at the L1 level of the spinal cord of a rat spinalized at T10-T11 produces a T-like rhythm

Cycling of clock genes entrained to the solar rhythm enables plants to tell time: data from arabidopsis

OpenAIRE

Yeang, Hoong-Yeet

2015-01-01

Background and Aims An endogenous rhythm synchronized to dawn cannot time photosynthesis-linked genes to peak consistently at noon since the interval between sunrise and noon changes seasonally. In this study, a solar clock model that circumvents this limitation is proposed using two daily timing references synchronized to noon and midnight. Other rhythmic genes that are not directly linked to photosynthesis, and which peak at other times, also find an adaptive advantage in entrainment to the...

Cumulative effect of X-ray radiation and inflammatory reaction on the circadian rhythm of tyrosine aminotransferase in the liver of mice

International Nuclear Information System (INIS)

Jungowska-Klin, B.

1980-01-01

The activity of tyrosine aminotransferase (TAT) in the liver of mice subjected simultaneously to ionizing radiation and to local inflammatory process showed in the first 24 hours of the experiment statistically significant changes resulting from summation of the harmful effects of both factors. In the second 24-hour period an evident tendency was observed for return of a normal circadian rhythm of the enzyme. This points to presence of an endogenous mechanism of suppression of the manifestations of significant desynchronization of the circadian rhythm. The paper contains also a trial of mathematical analysis of changes in TAT activity in the circadian rhythm, a description and analysis or the suppression process, qualitative and quantitative determination of the phenomenon of cumulation of the effects of powerful stress factors acting on the animal organism. The obtained results were compared with the results of investigations of TAT activity changes obtained in the case of separate application of the stress factors selected for this experiment. (author)

Serial binary interval ratios improve rhythm reproduction

Directory of Open Access Journals (Sweden)

Xiang eWu

2013-08-01

Full Text Available Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8, non-binary integer (1:3:5:6, and non-integer (1:2.3:5.3:6.4 ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

Serial binary interval ratios improve rhythm reproduction.

Science.gov (United States)

Wu, Xiang; Westanmo, Anders; Zhou, Liang; Pan, Junhao

2013-01-01

Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8), non-binary integer (1:3:5:6), and non-integer (1:2.3:5.3:6.4) ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

Circadian Rhythm Connections to Oxidative Stress: Implications for Human Health

Science.gov (United States)

Wilking, Melissa; Ndiaye, Mary; Mukhtar, Hasan

2013-01-01

Abstract Significance: Oxygen and circadian rhythmicity are essential in a myriad of physiological processes to maintain homeostasis, from blood pressure and sleep/wake cycles, down to cellular signaling pathways that play critical roles in health and disease. If the human body or cells experience significant stress, their ability to regulate internal systems, including redox levels and circadian rhythms, may become impaired. At cellular as well as organismal levels, impairment in redox regulation and circadian rhythms may lead to a number of adverse effects, including the manifestation of a variety of diseases such as heart diseases, neurodegenerative conditions, and cancer. Recent Advances: Researchers have come to an understanding as to the basics of the circadian rhythm mechanism, as well as the importance of the numerous species of oxidative stress components. The effects of oxidative stress and dysregulated circadian rhythms have been a subject of intense investigations since they were first discovered, and recent investigations into the molecular mechanisms linking the two have started to elucidate the bases of their connection. Critical Issues: While much is known about the mechanics and importance of oxidative stress systems and circadian rhythms, the front where they interact has had very little research focused on it. This review discusses the idea that these two systems are together intricately involved in the healthy body, as well as in disease. Future Directions: We believe that for a more efficacious management of diseases that have both circadian rhythm and oxidative stress components in their pathogenesis, targeting both systems in tandem would be far more successful. Antioxid. Redox Signal. 19, 192–208 PMID:23198849

Dissipative structures and biological rhythms

Science.gov (United States)

Goldbeter, Albert

2017-10-01

Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.

The role of feeding rhythm, adrenal hormones and neuronal inputs in synchronizing daily clock gene rhythms in the liver.

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Su, Yan; Cailotto, Cathy; Foppen, Ewout; Jansen, Remi; Zhang, Zhi; Buijs, Ruud; Fliers, Eric; Kalsbeek, Andries

2016-02-15

The master clock in the hypothalamic suprachiasmatic nucleus (SCN) is assumed to distribute rhythmic information to the periphery via neural, humoral and/or behavioral connections. Until now, feeding, corticosterone and neural inputs are considered important signals for synchronizing daily rhythms in the liver. In this study, we investigated the necessity of neural inputs as well as of the feeding and adrenal hormone rhythms for maintaining daily hepatic clock gene rhythms. Clock genes kept their daily rhythm when only one of these three signals was disrupted, or when we disrupted hepatic neuronal inputs together with the adrenal hormone rhythm or with the daily feeding rhythm. However, all clock genes studied lost their daily expression rhythm after simultaneous disruption of the feeding and adrenal hormone rhythm. These data indicate that either a daily rhythm of feeding or adrenal hormones should be present to synchronize clock gene rhythms in the liver with the SCN. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The role of the daily feeding rhythm in the regulation of the day/night rhythm in triglyceride secretion in rats.

Science.gov (United States)

Su, Yan; Foppen, Ewout; Mansur Machado, Frederico Sander; Fliers, Eric; Kalsbeek, Andries

2018-02-15

Plasma triglyceride (TG) levels show a clear daily rhythm, however, thus far it is still unknown whether this rhythm results from a daily rhythm in TG production, TG uptake or both. Previous studies have shown that feeding activity affects plasma TG concentrations, but it is not clear how the daily rhythm in feeding activity affects plasma TG concentrations. In the present study, we measured plasma TG concentrations and TG secretion rates in rats at 6 Zeitgeber times to investigate whether plasma TG concentrations and TG secretion show a daily rhythm. We found that plasma TG concentrations and TG secretion show a significant day/night rhythm. Next, we removed the daily rhythm in feeding behavior by introducing a 6-meals-a-day (6M) feeding schedule to investigate whether the daily rhythm in feeding behavior is necessary to maintain the daily rhythm in TG secretion. We found that the day/night rhythm in TG secretion was abolished under 6M feeding conditions. Hepatic apolipoprotein B (ApoB) and microsomal TG transfer protein (Mttp), which are both involved in TG secretion, also lost their daily rhythmicity under 6M feeding conditions. Together, these results indicate that: (1) the daily rhythm in TG secretion contributes to the formation of a day/night rhythm in plasma TG levels and (2) a daily feeding rhythm is essential for maintaining the daily rhythm in TG secretion.

Sleep and circadian rhythm disruption in social jetlag and mental illness.

Science.gov (United States)

Foster, Russell G; Peirson, Stuart N; Wulff, Katharina; Winnebeck, Eva; Vetter, Céline; Roenneberg, Till

2013-01-01

Sleep and wake represent two profoundly different states of physiology that arise within the brain from a complex interaction between multiple neural circuits and neurotransmitter systems. These neural networks are, in turn, adjusted by three key drivers that collectively determine the duration, quality, and efficiency of sleep. Two of these drivers are endogenous, namely, the circadian system and a homeostatic hourglass oscillator, while the third is exogenous-our societal structure (social time). In this chapter, we outline the neuroscience of sleep and highlight the links between sleep, mood, cognition, and mental health. We emphasize that the complexity of sleep/wake generation and regulation makes this behavioral cycle very vulnerable to disruption and then explore this concept by examining sleep and circadian rhythm disruption (SCRD) when the exogenous and endogenous drivers of sleep are in conflict. SCRD can be particularly severe when social timing forces an abnormal pattern of sleep and wake upon our endogenous sleep biology. SCRD is also very common in mental illness, and although well known, this association is poorly understood or treated. Recent studies suggest that the generation of sleep and mental health shares overlapping neural mechanisms such that defects in these endogenous pathways result in pathologies to both behaviors. The evidence for this association is examined in some detail. We conclude this review by suggesting that the emerging understanding of the neurobiology of sleep/wake behavior, and of the health consequences of sleep disruption, will provide new ways to decrease the conflict between biological and societal timing in both the healthy and individuals with mental illness. © 2013, Elsevier Inc. All Rights Reserved.

Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine.

Science.gov (United States)

Pagel, René; Bär, Florian; Schröder, Torsten; Sünderhauf, Annika; Künstner, Axel; Ibrahim, Saleh M; Autenrieth, Stella E; Kalies, Kathrin; König, Peter; Tsang, Anthony H; Bettenworth, Dominik; Divanovic, Senad; Lehnert, Hendrik; Fellermann, Klaus; Oster, Henrik; Derer, Stefanie; Sina, Christian

2017-11-01

Endogenous circadian clocks regulate 24-h rhythms of physiology and behavior. Circadian rhythm disruption (CRD) is suggested as a risk factor for inflammatory bowel disease. However, the underlying molecular mechanisms remain unknown. Intestinal biopsies from Per1/2 mutant and wild-type (WT) mice were investigated by electron microscopy, immunohistochemistry, and bromodeoxyuridine pulse-chase experiments. TNF-α was injected intraperitoneally, with or without necrostatin-1, into Per1/2 mice or rhythmic and externally desynchronized WT mice to study intestinal epithelial cell death. Experimental chronic colitis was induced by oral administration of dextran sodium sulfate. In vitro , caspase activity was assayed in Per1/2-specific small interfering RNA-transfected cells. Wee1 was overexpressed to study antiapoptosis and the cell cycle. Genetic ablation of circadian clock function or environmental CRD in mice increased susceptibility to severe intestinal inflammation and epithelial dysregulation, accompanied by excessive necroptotic cell death and a reduced number of secretory epithelial cells. Receptor-interacting serine/threonine-protein kinase (RIP)-3-mediated intestinal necroptosis was linked to increased mitotic cell cycle arrest via Per1/2-controlled Wee1, resulting in increased antiapoptosis via cellular inhibitor of apoptosis-2. Together, our data suggest that circadian rhythm stability is pivotal for the maintenance of mucosal barrier function. CRD increases intestinal necroptosis, thus rendering the gut epithelium more susceptible to inflammatory processes.-Pagel, R., Bär, F., Schröder, T., Sünderhauf, A., Künstner, A., Ibrahim, S. M., Autenrieth, S. E., Kalies, K., König, P., Tsang, A. H., Bettenworth, D., Divanovic, S., Lehnert, H., Fellermann, K., Oster, H., Derer, S., Sina, C. Circadian rhythm disruption impairs tissue homeostasis and exacerbates chronic inflammation in the intestine. © FASEB.

Endogenous activation of adenosine A(1) receptors accelerates ischemic suppression of spontaneous electrocortical activity

DEFF Research Database (Denmark)

Ilie, Andrei; Ciocan, Dragos; Zagrean, Ana-Maria

2006-01-01

Cerebral ischemia induces a rapid suppression of spontaneous brain rhythms prior to major alterations in ionic homeostasis. It was found in vitro during ischemia that the rapidly formed adenosine, resulting from the intracellular breakdown of ATP, may inhibit synaptic transmission via the A(1......) receptor subtype. The link between endogenous A(1) receptor activation during ischemia and the suppression of spontaneous electrocortical activity has not yet been established in the intact brain. The aim of this study was to investigate in vivo the effects of A(1) receptor antagonism by 8-cyclopentyl-1...

Deciphering the Function of the Blunt Circadian Rhythm of Melatonin in the Newborn Lamb: Impact on Adrenal and Heart.

Science.gov (United States)

Seron-Ferre, Maria; Torres-Farfan, Claudia; Valenzuela, Francisco J; Castillo-Galan, Sebastian; Rojas, Auristela; Mendez, Natalia; Reynolds, Henry; Valenzuela, Guillermo J; Llanos, Anibal J

2017-09-01

Neonatal lambs, as with human and other neonates, have low arrhythmic endogenous levels of melatonin for several weeks until they start their own pineal rhythm of melatonin production at approximately 2 weeks of life. During pregnancy, daily rhythmic transfer of maternal melatonin to the fetus has important physiological roles in sheep, nonhuman primates, and rats. This melatonin rhythm provides a circadian signal and also participates in adjusting the physiology of several organs in preparation for extrauterine life. We propose that the ensuing absence of a melatonin rhythm plays a role in neonatal adaptation. To test this hypothesis, we studied the effects of imposing a high-amplitude melatonin rhythm in the newborn lamb on (1) clock time-related changes in cortisol and plasma variables and (2) clock time-related changes of gene expression of clock genes and selected functional genes in the adrenal gland and heart. We treated newborn lambs with a daily oral dose of melatonin (0.25 mg/kg) from birth to 5 days of age, recreating a high-amplitude melatonin rhythm. This treatment suppressed clock time-related changes of plasma adrenocorticotropic hormone, cortisol, clock gene expression, and functional genes in the newborn adrenal gland. In the heart, it decreased heart/body weight ratio, increased expression of Anp and Bnp, and resulted in different heart gene expression from control newborns. The interference of this postnatal melatonin treatment with the normal postnatal pattern of adrenocortical function and heart development support a physiological role for the window of flat postnatal melatonin levels during the neonatal transition. Copyright © 2017 Endocrine Society.

Factors influencing circadian rhythms in acetaminophen lethality.

Science.gov (United States)

Schnell, R C; Bozigian, H P; Davies, M H; Merrick, B A; Park, K S; McMillan, D A

1984-01-01

Experiments were conducted to examine the effects of changes in lighting schedules and food consumption on circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice. Under a normal lighting schedule (light: 06.00-18.00 h), male mice exhibited a circadian rhythm in acetaminophen lethality (peak: 18.00 h; nadir: 06.00, 10.00 h) and an inverse rhythm in hepatic glutathione concentrations (peak: 06.00, 10.00 h; nadir: 18.00 h). Under a reversed lighting schedule (light: 18.00-06.00 h) the glutathione rhythm was reversed and the rhythm in acetaminophen lethality was altered showing greater sensitivity to the drug. Under continuous light, there was a shift in the acetaminophen lethality and the hepatic glutathione rhythms. Under continuous dark, both rhythms were abolished. Under a normal lighting regimen, hepatic glutathione levels were closely correlated with food consumption; i.e., both were increased during the dark phase and decreased during the light phase. Fasting the mice for 12 h abolished the rhythms in acetaminophen lethality and hepatic glutathione levels; moreover, the lethality was increased and the hepatic glutathione levels were decreased. These experiments show that both lighting schedules and feeding can alter the circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice.

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F.

2018-02-26

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host’s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host’s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F

2017-12-07

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host\\'s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host\\'s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

The evolutionary biology of musical rhythm: was Darwin wrong?

Science.gov (United States)

Patel, Aniruddh D

2014-03-01

In The Descent of Man, Darwin speculated that our capacity for musical rhythm reflects basic aspects of brain function broadly shared among animals. Although this remains an appealing idea, it is being challenged by modern cross-species research. This research hints that our capacity to synchronize to a beat, i.e., to move in time with a perceived pulse in a manner that is predictive and flexible across a broad range of tempi, may be shared by only a few other species. Is this really the case? If so, it would have important implications for our understanding of the evolution of human musicality.

Cognitive performance as a zeitgeber: cognitive oscillators and cholinergic modulation of the SCN entrain circadian rhythms.

Directory of Open Access Journals (Sweden)

Howard J Gritton

Full Text Available The suprachiasmatic nucleus (SCN is the primary circadian pacemaker in mammals that can synchronize or entrain to environmental cues. Although light exerts powerful influences on SCN output, other non-photic stimuli can modulate the SCN as well. We recently demonstrated that daily performance of a cognitive task requiring sustained periods of attentional effort that relies upon basal forebrain (BF cholinergic activity dramatically alters circadian rhythms in rats. In particular, normally nocturnal rats adopt a robust diurnal activity pattern that persists for several days in the absence of cognitive training. Although anatomical and pharmacological data from non-performing animals support a relationship between cholinergic signaling and circadian rhythms, little is known about how endogenous cholinergic signaling influences SCN function in behaving animals. Here we report that BF cholinergic projections to the SCN provide the principal signal allowing for the expression of cognitive entrainment in light-phase trained animals. We also reveal that oscillator(s outside of the SCN drive cognitive entrainment as daily timed cognitive training robustly entrains SCN-lesioned arrhythmic animals. Ablation of the SCN, however, resulted in significant impairments in task acquisition, indicating that SCN-mediated timekeeping benefits new learning and cognitive performance. Taken together, we conclude that cognition entrains non-photic oscillators, and cholinergic signaling to the SCN serves as a temporal timestamp attenuating SCN photic-driven rhythms, thereby permitting cognitive demands to modulate behavior.

Circadian rhythmicity of active GSK3 isoforms modulates molecular clock gene rhythms in the suprachiasmatic nucleus.

Science.gov (United States)

Besing, Rachel C; Paul, Jodi R; Hablitz, Lauren M; Rogers, Courtney O; Johnson, Russell L; Young, Martin E; Gamble, Karen L

2015-04-01

The suprachiasmatic nucleus (SCN) drives and synchronizes daily rhythms at the cellular level via transcriptional-translational feedback loops comprising clock genes such as Bmal1 and Period (Per). Glycogen synthase kinase 3 (GSK3), a serine/threonine kinase, phosphorylates at least 5 core clock proteins and shows diurnal variation in phosphorylation state (inactivation) of the GSK3β isoform. Whether phosphorylation of the other primary isoform (GSK3α) varies across the subjective day-night cycle is unknown. The purpose of this study was to determine if the endogenous rhythm of GSK3 (α and β) phosphorylation is critical for rhythmic BMAL1 expression and normal amplitude and periodicity of the molecular clock in the SCN. Significant circadian rhythmicity of phosphorylated GSK3 (α and β) was observed in the SCN from wild-type mice housed in constant darkness for 2 weeks. Importantly, chronic activation of both GSK3 isoforms impaired rhythmicity of the GSK3 target BMAL1. Furthermore, chronic pharmacological inhibition of GSK3 with 20 µM CHIR-99021 enhanced the amplitude and shortened the period of PER2::luciferase rhythms in organotypic SCN slice cultures. These results support the model that GSK3 activity status is regulated by the circadian clock and that GSK3 feeds back to regulate the molecular clock amplitude in the SCN. © 2015 The Author(s).

Uncovering the mystery of opposite circadian rhythms between mouse and human leukocytes in humanized mice.

Science.gov (United States)

Zhao, Yue; Liu, Min; Chan, Xue Ying; Tan, Sue Yee; Subramaniam, Sharrada; Fan, Yong; Loh, Eva; Chang, Kenneth Tou En; Tan, Thiam Chye; Chen, Qingfeng

2017-11-02

Many immune parameters show circadian rhythms during the 24-hour day in mammals. The most striking circadian oscillation is the number of circulating immune cells that display an opposite rhythm between humans and mice. The physiological roles and mechanisms of circadian variations in mouse leukocytes are well studied, whereas for humans they remain unclear because of the lack of a proper model. In this study, we found that consistent with their natural host species, mouse and human circulating leukocytes exhibited opposite circadian oscillations in humanized mice. This cyclic pattern of trafficking correlated well with the diurnal expression levels of C-X-C chemokine receptor 4, which were controlled by the intracellular hypoxia-inducible factor 1α/aryl hydrocarbon receptor nuclear translocator-like heterodimer. Furthermore, we also discovered that p38 mitogen-activated protein kinases/mitogen-activated 2 had opposite effects between mice and humans in generating intracellular reactive oxygen species, which subsequently regulated HIF-1α expression. In conclusion, we propose humanized mice as a robust model for human circadian studies and reveal insights on a novel molecular clock network in the human circadian rhythm. © 2017 by The American Society of Hematology.

Moscatilin Inhibits Lung Cancer Cell Motility and Invasion via Suppression of Endogenous Reactive Oxygen Species

Directory of Open Access Journals (Sweden)

Akkarawut Kowitdamrong

2013-01-01

Full Text Available Lung cancer is the leading cause of death among cancer patients worldwide, and most of them have died from metastasis. Migration and invasion are prerequisite processes associated with high metastasis potential in cancers. Moscatilin, a bibenzyl derivative isolated from the Thai orchid Dendrobium pulchellum, has been shown to have anticancer effect against numerous cancer cell lines. However, little is known regarding the effect of moscatilin on cancer cell migration and invasion. The present study demonstrates that nontoxic concentrations of moscatilin were able to inhibit human nonsmall cell lung cancer H23 cell migration and invasion. The inhibitory effect of moscatilin was associated with an attenuation of endogenous reactive oxygen species (ROS, in which hydroxyl radical (OH∙ was identified as a dominant species in the suppression of filopodia formation. Western blot analysis also revealed that moscatilin downregulated activated focal adhesion kinase (phosphorylated FAK, Tyr 397 and activated ATP-dependent tyrosine kinase (phosphorylated Akt, Ser 473, whereas their parental counterparts were not detectable changed. In conclusion, our results indicate the novel molecular basis of moscalitin-inhibiting lung cancer cell motility and invasion and demonstrate a promising antimetastatic potential of such an agent for lung cancer therapy.

Circadian Rhythm Disruption Promotes Lung Tumorigenesis.

Science.gov (United States)

Papagiannakopoulos, Thales; Bauer, Matthew R; Davidson, Shawn M; Heimann, Megan; Subbaraj, Lakshmipriya; Bhutkar, Arjun; Bartlebaugh, Jordan; Vander Heiden, Matthew G; Jacks, Tyler

2016-08-09

Circadian rhythms are 24-hr oscillations that control a variety of biological processes in living systems, including two hallmarks of cancer, cell division and metabolism. Circadian rhythm disruption by shift work is associated with greater risk for cancer development and poor prognosis, suggesting a putative tumor-suppressive role for circadian rhythm homeostasis. Using a genetically engineered mouse model of lung adenocarcinoma, we have characterized the effects of circadian rhythm disruption on lung tumorigenesis. We demonstrate that both physiologic perturbation (jet lag) and genetic mutation of the central circadian clock components decreased survival and promoted lung tumor growth and progression. The core circadian genes Per2 and Bmal1 were shown to have cell-autonomous tumor-suppressive roles in transformation and lung tumor progression. Loss of the central clock components led to increased c-Myc expression, enhanced proliferation, and metabolic dysregulation. Our findings demonstrate that both systemic and somatic disruption of circadian rhythms contribute to cancer progression. Copyright © 2016 Elsevier Inc. All rights reserved.

The evolutionary biology of musical rhythm: was Darwin wrong?

Directory of Open Access Journals (Sweden)

Aniruddh D Patel

2014-03-01

Full Text Available In The Descent of Man, Darwin speculated that our capacity for musical rhythm reflects basic aspects of brain function broadly shared among animals. Although this remains an appealing idea, it is being challenged by modern cross-species research. This research hints that our capacity to synchronize to a beat, i.e., to move in time with a perceived pulse in a manner that is predictive and flexible across a broad range of tempi, may be shared by only a few other species. Is this really the case? If so, it would have important implications for our understanding of the evolution of human musicality.

The Rhetorical Nature of Rhythm

NARCIS (Netherlands)

Balint, Mihaela; Dascalu, Mihai; Trausan-Matu, Stefan

2017-01-01

Up to date, linguistic rhythm has been studied for speech, but the rhythm of written texts has been merely recognized, and not analyzed or interpreted in connection to natural language tasks. We provide an extension of the textual rhythmic features we proposed in previous work, and

Learning by joining the rhythm

DEFF Research Database (Denmark)

Lund, Ole; Ravn, Susanne; Christensen, Mette Krogh

2012-01-01

This article aims to explore how a joint rhythm is learned. The exploration is based on a combination of a case study of training in elite rowing and theoretical considerations concerning mutual incorporation of skills in learning. In 2009 Juliane and Anne start to row the double sculler together....... The two rowers’ aim is to be among the exclusive group of teams that qualify for the Olympic Games three years later. However Anne is not a rower, and has to be apprenticed by Juliane, who is an experienced elite rower. One important learning goal in the apprenticeship is to find a good joint rhythm......, to be able to put optimal effort into the rowing. Thus the apprenticeship is about developing a sense for a good rhythm in Anne which corresponds to Juliane’s fine-grained sense of what a good rhythm should feel like. Our study suggests that apprenticeship learning has to be understood as an embodied...

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F.; van der Veen, Daan R.; O’ Donnell, Aidan J.; Cumnock, Katherine; Schneider, David; Pain, Arnab; Subudhi, Amit; Ramaprasad, Abhinay; Rund, Samuel S. C.; Savill, Nicholas J.; Reece, Sarah E.

2018-01-01

by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms

Modulation of Somatosensory Alpha Rhythm by Transcranial Alternating Current Stimulation at Mu-Frequency

Directory of Open Access Journals (Sweden)

Christopher Gundlach

2017-08-01

Full Text Available Introduction: Transcranial alternating current stimulation (tACS is emerging as an interventional tool to modulate different functions of the brain, potentially by interacting with intrinsic ongoing neuronal oscillations. Functionally different intrinsic alpha oscillations are found throughout the cortex. Yet it remains unclear whether tACS is capable of specifically modulating the somatosensory mu-rhythm in amplitude.Objectives: We used tACS to modulate mu-alpha oscillations in amplitude. When compared to sham stimulation we expected a modulation of mu-alpha oscillations but not visual alpha oscillations by tACS.Methods: Individual mu-alpha frequencies were determined in 25 participants. Subsequently, blocks of tACS with individual mu-alpha frequency and sham stimulation were applied over primary somatosensory cortex (SI. Electroencephalogram (EEG was recorded before and after either stimulation or sham. Modulations of mu-alpha and, for control, visual alpha amplitudes were then compared between tACS and sham.Results: Somatosensory mu-alpha oscillations decreased in amplitude after tACS was applied at participants’ individual mu-alpha frequency. No changes in amplitude were observed for sham stimulation. Furthermore, visual alpha oscillations were not affected by tACS or sham, respectively.Conclusion: Our results demonstrate the capability of tACS to specifically modulate the targeted somatosensory mu-rhythm when the tACS frequency is tuned to the individual endogenous rhythm and applied over somatosensory areas. Our results are in contrast to previously reported amplitude increases of visual alpha oscillations induced by tACS applied over visual cortex. Our results may point to a specific interaction between our stimulation protocol and the functional architecture of the somatosensory system.

RNAi of the circadian clock gene period disrupts the circadian rhythm but not the circatidal rhythm in the mangrove cricket

OpenAIRE

Takekata, Hiroki; Matsuura, Yu; Goto, Shin G.; Satoh, Aya; Numata, Hideharu

2012-01-01

The clock mechanism for circatidal rhythm has long been controversial, and its molecular basis is completely unknown. The mangrove cricket, Apteronemobius asahinai, shows two rhythms simultaneously in its locomotor activity: a circatidal rhythm producing active and inactive phases as well as a circadian rhythm modifying the activity intensity of circatidal active phases. The role of the clock gene period (per), one of the key components of the circadian clock in insects, was investigated in t...

The discoveries of molecular mechanisms for the circadian rhythm: The 2017 Nobel Prize in Physiology or Medicine.

Science.gov (United States)

Huang, Rong-Chi

2018-02-01

Circadian clocks evolved to allow plants and animals to adapt their behaviors to the 24-hr change in the external environment due to the Earth's rotation. While the first scientific observation of circadian rhythm in the plant leaf movement may be dated back to the early 18th century, it took 200 years to realize that the leaf movement is controlled by an endogenous circadian clock. The cloning and characterization of the first Drosophila clock gene period in the early 1980s, independently by Jeffery C. Hall and Michael Rosbash at Brandeis University and Michael Young at Rockefeller University, paved the way for their further discoveries of additional genes and proteins, culminating in establishing the so-called transcriptional translational feedback loop (TTFL) model for the generation of autonomous oscillator with a period of ∼24 h. The 2017 Nobel Prize in Physiology or Medicine was awarded to honor their discoveries of molecular mechanisms controlling the circadian rhythm. Copyright © 2018 Chang Gung University. Published by Elsevier B.V. All rights reserved.

Cross-Cultural Influences on Rhythm Processing: Reproduction, Discrimination, and Beat Tapping

Directory of Open Access Journals (Sweden)

Daniel J Cameron

2015-04-01

Full Text Available The structures of musical rhythm differ between cultures, despite the fact that the ability to synchronize one’s movements to musical rhythms appears to be universal. To measure the influence of culture on rhythm processing, we tested East African and North American adults on the perception, production, and beat tapping of rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced both by the culture of the participant and by the culture of the rhythm. Specifically, we predicted that a participant’s ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than unfamiliar rhythms. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

Exogenous vs. Endogenous Separation

OpenAIRE

Ramey, Garey

2008-01-01

This paper assesses how various approaches to modelling the separation margin a¤ect the ability of the Mortensen-Pissarides job matching model to explain key facts about the aggregate labor market. Allowing for realistic time variation in the separation rate, whether exogenous or endogenous, greatly in- creases the unemployment variability generated by the model. Speci…cations with exogenous separation rates, whether constant or time-varying, fail to pro- duce realistic volatility and prod...

Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping.

Science.gov (United States)

Cameron, Daniel J; Bentley, Jocelyn; Grahn, Jessica A

2015-01-01

The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced by the culture of the participant and the culture of the rhythm. Specifically, we predicted that a participant's ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

Endogenous bile acid disposition in rat and human sandwich-cultured hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Marion, Tracy L., E-mail: tracylmarion@qualyst.com [Curriculum in Toxicology, UNC School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7270 (United States); Perry, Cassandra H., E-mail: cassandraperry@qualyst.com [Qualyst, Inc., Durham, NC 27713 (United States); St Claire, Robert L., E-mail: bobstclaire@qualyst.com [Qualyst, Inc., Durham, NC 27713 (United States); Brouwer, Kim L.R., E-mail: kbrouwer@unc.edu [Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, CB 7569 Kerr Hall, Chapel Hill, NC 27599-7569 (United States)

2012-05-15

Sandwich-cultured hepatocytes (SCH) are used commonly to investigate hepatic transport protein-mediated uptake and biliary excretion of substrates. However, little is known about the disposition of endogenous bile acids (BAs) in SCH. In this study, four endogenous conjugated BAs common to rats and humans [taurocholic acid (TCA), glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), and glycochenodeoxycholic acid (GCDCA)], as well as two BA species specific to rodents (α- and β-tauromuricholic acid; α/β TMCA), were profiled in primary rat and human SCH. Using B-CLEAR{sup ®} technology, BAs were measured in cells + bile canaliculi, cells, and medium of SCH by LC-MS/MS. Results indicated that, just as in vivo, taurine-conjugated BA species were predominant in rat SCH, while glycine-conjugated BAs were predominant in human SCH. Total intracellular BAs remained relatively constant over days in culture in rat SCH. Total BAs in control (CTL) cells + bile, cells, and medium were approximately 3.4, 2.9, and 8.3-fold greater in human than in rat. The estimated intracellular concentrations of the measured total BAs were 64.3 ± 5.9 μM in CTL rat and 183 ± 56 μM in CTL human SCH, while medium concentrations of the total BAs measured were 1.16 ± 0.21 μM in CTL rat SCH and 9.61 ± 6.36 μM in CTL human SCH. Treatment of cells for 24 h with 10 μM troglitazone (TRO), an inhibitor of the bile salt export pump (BSEP) and the Na{sup +}-taurocholate cotransporting polypeptide (NTCP), had no significant effect on endogenous BAs measured at the end of the 24-h culture period, potentially due to compensatory mechanisms that maintain BA homeostasis. These data demonstrate that BAs in SCH are similar to in vivo, and that SCH may be a useful in vitro model to study alterations in BA disposition if species differences are taken into account. -- Highlights: ► Bile acids (BAs) were measured in rat and human sandwich-cultured hepatocytes (SCH). ► Cell and medium BA

Endogenous bile acid disposition in rat and human sandwich-cultured hepatocytes

International Nuclear Information System (INIS)

Marion, Tracy L.; Perry, Cassandra H.; St Claire, Robert L.; Brouwer, Kim L.R.

2012-01-01

Sandwich-cultured hepatocytes (SCH) are used commonly to investigate hepatic transport protein-mediated uptake and biliary excretion of substrates. However, little is known about the disposition of endogenous bile acids (BAs) in SCH. In this study, four endogenous conjugated BAs common to rats and humans [taurocholic acid (TCA), glycocholic acid (GCA), taurochenodeoxycholic acid (TCDCA), and glycochenodeoxycholic acid (GCDCA)], as well as two BA species specific to rodents (α- and β-tauromuricholic acid; α/β TMCA), were profiled in primary rat and human SCH. Using B-CLEAR ® technology, BAs were measured in cells + bile canaliculi, cells, and medium of SCH by LC-MS/MS. Results indicated that, just as in vivo, taurine-conjugated BA species were predominant in rat SCH, while glycine-conjugated BAs were predominant in human SCH. Total intracellular BAs remained relatively constant over days in culture in rat SCH. Total BAs in control (CTL) cells + bile, cells, and medium were approximately 3.4, 2.9, and 8.3-fold greater in human than in rat. The estimated intracellular concentrations of the measured total BAs were 64.3 ± 5.9 μM in CTL rat and 183 ± 56 μM in CTL human SCH, while medium concentrations of the total BAs measured were 1.16 ± 0.21 μM in CTL rat SCH and 9.61 ± 6.36 μM in CTL human SCH. Treatment of cells for 24 h with 10 μM troglitazone (TRO), an inhibitor of the bile salt export pump (BSEP) and the Na + -taurocholate cotransporting polypeptide (NTCP), had no significant effect on endogenous BAs measured at the end of the 24-h culture period, potentially due to compensatory mechanisms that maintain BA homeostasis. These data demonstrate that BAs in SCH are similar to in vivo, and that SCH may be a useful in vitro model to study alterations in BA disposition if species differences are taken into account. -- Highlights: ► Bile acids (BAs) were measured in rat and human sandwich-cultured hepatocytes (SCH). ► Cell and medium BA concentrations

The importance of hormonal circadian rhythms in daily feeding patterns: An illustration with simulated pigs.

Science.gov (United States)

Boumans, Iris J M M; de Boer, Imke J M; Hofstede, Gert Jan; la Fleur, Susanne E; Bokkers, Eddie A M

2017-07-01

The interaction between hormonal circadian rhythms and feeding behaviour is not well understood. This study aimed to deepen our understanding of mechanisms underlying circadian feeding behaviour in animals, using pigs, Sus scrofa, as a case study. Pigs show an alternans feeding pattern, that is, a small peak of feed intake at the beginning of the day and a larger peak at the end of the day. We simulated the feeding behaviour of pigs over a 24h period. The simulation model contained mechanisms that regulate feeding behaviour of animals, including: processing of feed in the gastrointestinal tract, fluctuation in energy balance, circadian rhythms of melatonin and cortisol and motivational decision-making. From the interactions between these various processes, feeding patterns (e.g. feed intake, meal frequency, feeding rate) emerge. These feeding patterns, as well as patterns for the underlying mechanisms (e.g. energy expenditure), fitted empirical data well, indicating that our model contains relevant mechanisms. The circadian rhythms of cortisol and melatonin explained the alternans pattern of feeding in pigs. Additionally, the timing and amplitude of cortisol peaks affected the diurnal and nocturnal peaks in feed intake. Furthermore, our results suggest that circadian rhythms of other hormones, such as leptin and ghrelin, are less important in circadian regulation of feeding behaviour than previously thought. These results are relevant to animal species with a metabolic and endocrine system similar to that of pigs, such as humans. Moreover, the modelling approach to understand feeding behaviour can be applied to other animal species. Copyright © 2017 Elsevier Inc. All rights reserved.

Circadian Rhythms

Indian Academy of Sciences (India)

IAS Admin

nature of the system underlying such rhythms and inspired one of the ... behaviours and physiological processes were discovered in a wide range of animals. ... is thought to coordinate internal physiology, and thereby confer benefits to living ...

Endogenous viral elements in animal genomes.

Directory of Open Access Journals (Sweden)

Aris Katzourakis

2010-11-01

Full Text Available Integration into the nuclear genome of germ line cells can lead to vertical inheritance of retroviral genes as host alleles. For other viruses, germ line integration has only rarely been documented. Nonetheless, we identified endogenous viral elements (EVEs derived from ten non-retroviral families by systematic in silico screening of animal genomes, including the first endogenous representatives of double-stranded RNA, reverse-transcribing DNA, and segmented RNA viruses, and the first endogenous DNA viruses in mammalian genomes. Phylogenetic and genomic analysis of EVEs across multiple host species revealed novel information about the origin and evolution of diverse virus groups. Furthermore, several of the elements identified here encode intact open reading frames or are expressed as mRNA. For one element in the primate lineage, we provide statistically robust evidence for exaptation. Our findings establish that genetic material derived from all known viral genome types and replication strategies can enter the animal germ line, greatly broadening the scope of paleovirological studies and indicating a more significant evolutionary role for gene flow from virus to animal genomes than has previously been recognized.

Dysrhythmia: a specific congenital rhythm perception deficit

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Jacques eLaunay

2014-02-01

Full Text Available Why do some people have problems ‘feeling the beat’? Here we investigate participants with congenital impairments in musical rhythm perception and production. A web-based version of the Montreal Battery of Evaluation of Amusia (MBEA was used to screen for difficulties with rhythmic processing in a large sample and we identified three ‘dysrhythmic’ individuals who scored below cut-off for the rhythm subtest, but not the pitch-based subtests. Follow-up testing in the laboratory was conducted to characterize the nature of both rhythm perception and production deficits in these dysrhythmic individuals. We found that they differed from control participants when required to synchronize their tapping to an external stimulus with a metrical pulse, but not when required to tap spontaneously (with no external stimulus or to tap in time to an isochronous stimulus. Dysrhythmics exhibited a general tendency to tap at half the expected tempo when asked to synchronize to the beat of strongly metrical rhythms. These results suggest that the individuals studied here did not have motor production problems, but suffer from a selective rhythm perception deficit that influences the ability to entrain to metrical rhythms.

Dim nighttime illumination interacts with parametric effects of bright light to increase the stability of circadian rhythm bifurcation in hamsters.

Science.gov (United States)

Evans, Jennifer A; Elliott, Jeffrey A; Gorman, Michael R

2011-07-01

The endogenous circadian pacemaker of mammals is synchronized to the environmental day by the ambient cycle of relative light and dark. The present studies assessed the actions of light in a novel circadian entrainment paradigm where activity rhythms are bifurcated following exposure to a 24-h light:dark:light:dark (LDLD) cycle. Bifurcated entrainment under LDLD reflects the temporal dissociation of component oscillators that comprise the circadian system and is facilitated when daily scotophases are dimly lit rather than completely dark. Although bifurcation can be stably maintained in LDLD, it is quickly reversed under constant conditions. Here the authors examine whether dim scotophase illumination acts to maintain bifurcated entrainment under LDLD through potential interactions with the parametric actions of bright light during the two daily photophases. In three experiments, wheel-running rhythms of Syrian hamsters were bifurcated under LDLD with dimly lit scotophases, and after several weeks, dim scotophase illumination was either retained or extinguished. Additionally, "full" and "skeleton" photophases were employed under LDLD cycles with dimly lit or completely dark scotophases to distinguish parametric from nonparametric effects of bright light. Rhythm bifurcation was more stable in full versus skeleton LDLD cycles. Dim light facilitated the maintenance of bifurcated entrainment under full LDLD cycles but did not prevent the loss of rhythm bifurcation in skeleton LDLD cycles. These studies indicate that parametric actions of bright light maintain the bifurcated entrainment state; that dim scotophase illumination increases the stability of the bifurcated state; and that dim light interacts with the parametric effects of bright light to increase the stability of rhythm bifurcation under full LDLD cycles. A further understanding of the novel actions of dim light may lead to new strategies for understanding, preventing, and treating chronobiological

Acquisition of speech rhythm in first language.

Science.gov (United States)

Polyanskaya, Leona; Ordin, Mikhail

2015-09-01

Analysis of English rhythm in speech produced by children and adults revealed that speech rhythm becomes increasingly more stress-timed as language acquisition progresses. Children reach the adult-like target by 11 to 12 years. The employed speech elicitation paradigm ensured that the sentences produced by adults and children at different ages were comparable in terms of lexical content, segmental composition, and phonotactic complexity. Detected differences between child and adult rhythm and between rhythm in child speech at various ages cannot be attributed to acquisition of phonotactic language features or vocabulary, and indicate the development of language-specific phonetic timing in the course of acquisition.

The role of the daily feeding rhythm in the regulation of the day/night rhythm in triglyceride secretion in rats

NARCIS (Netherlands)

Su, Yan; Foppen, Ewout; Mansur Machado, Frederico Sander; Fliers, Eric; Kalsbeek, A.

2018-01-01

Plasma triglyceride (TG) levels show a clear daily rhythm, however, thus far it is still unknown whether this rhythm results from a daily rhythm in TG production, TG uptake or both. Previous studies have shown that feeding activity affects plasma TG concentrations, but it is not clear how the daily

Spontaneous internal desynchronization of locomotor activity and body temperature rhythms from plasma melatonin rhythm in rats exposed to constant dim light

Directory of Open Access Journals (Sweden)

Bullock Nicole M

2006-04-01

Full Text Available Abstract Background We have recently reported that spontaneous internal desynchronization between the locomotor activity rhythm and the melatonin rhythm may occur in rats (30% of tested animals when they are maintained in constant dim red light (LLdim for 60 days. Previous work has also shown that melatonin plays an important role in the modulation of the circadian rhythms of running wheel activity (Rw and body temperature (Tb. The aim of the present study was to investigate the effect that desynchronization of the melatonin rhythm may have on the coupling and expression of circadian rhythms in Rw and Tb. Methods Rats were maintained in a temperature controlled (23–24°C ventilated lightproof room under LLdim (red dim light 1 μW/cm2 [5 Lux], lower wavelength cutoff at 640 nm. Animals were individually housed in cages equipped with a running wheel and a magnetic sensor system to detect wheel rotation; Tb was monitored by telemetry. Tb and Rw data were recorded in 5-min bins and saved on disk. For each animal, we determined the mesor and the amplitude of the Rw and Tb rhythm using waveform analysis on 7-day segments of the data. After sixty days of LLdim exposure, blood samples (80–100 μM were collected every 4 hours over a 24-hrs period from the tail artery, and serum melatonin levels were measured by radioimmunoassay. Results Twenty-one animals showed clear circadian rhythms Rw and Tb, whereas one animal was arrhythmic. Rw and Tb rhythms were always strictly associated and we did not observe desynchronization between these two rhythms. Plasma melatonin levels showed marked variations among individuals in the peak levels and in the night-to-day ratio. In six rats, the night-to-day ratio was less than 2, whereas in the rat that showed arrhythmicity in Rw and Tb melatonin levels were high and rhythmic with a large night-to-day ratio. In seven animals, serum melatonin levels peaked during the subjective day (from CT0 to CT8, thus suggesting

Diurnal rhythms in psychological reward functioning in healthy young men: 'Wanting', liking, and learning.

Science.gov (United States)

Byrne, Jamie E M; Murray, Greg

2017-01-01

A range of evidence suggests that human reward functioning is partly driven by the endogenous circadian system, generating 24-hour rhythms in behavioural measures of reward activation. Reward functioning is multifaceted but literature to date is largely limited to measures of self-reported positive mood states. The aim of this study was to advance the field by testing for hypothesised diurnal variation in previously unexplored components of psychological reward: 'wanting', liking, and learning using subjective and behavioural measures. Risky decision making (automatic Balloon Analogue Risk Task), affective responsivity to positive images (International Affective Pictures System), uncued self-reported discrete emotions, and learning-contingent reward (Iowa Gambling Task) were measured at 10.00 hours, 14.00 hours, and 19.00 hours in a counterbalanced repeated measures design with 50 healthy male participants (aged 18-30). As hypothesised, risky decision making (unconscious 'wanting') and ratings of arousal towards positive images (conscious wanting) exhibited a diurnal waveform with indices highest at 14.00 hours. No diurnal rhythm was observed for liking (pleasure ratings to positive images, discrete uncued positive emotions) or in a learning-contingent reward task. Findings reaffirm that diurnal variation in human reward functioning is most pronounced in the motivational 'wanting' components of reward.

Circadian Rhythms

Indian Academy of Sciences (India)

IAS Admin

Early studies on circadian rhythms focussed on unravelling the fundamental .... careful analysis revealed that deaths of most arrhythmic indi- viduals were due to .... is no more a sci-fi movie script and is achievable through a technique called ...

Rhythm information represented in the fronto-parieto-cerebellar motor system.

Science.gov (United States)

Konoike, Naho; Kotozaki, Yuka; Miyachi, Shigehiro; Miyauchi, Carlos Makoto; Yomogida, Yukihito; Akimoto, Yoritaka; Kuraoka, Koji; Sugiura, Motoaki; Kawashima, Ryuta; Nakamura, Katsuki

2012-10-15

Rhythm is an essential element of human culture, particularly in language and music. To acquire language or music, we have to perceive the sensory inputs, organize them into structured sequences as rhythms, actively hold the rhythm information in mind, and use the information when we reproduce or mimic the same rhythm. Previous brain imaging studies have elucidated brain regions related to the perception and production of rhythms. However, the neural substrates involved in the working memory of rhythm remain unclear. In addition, little is known about the processing of rhythm information from non-auditory inputs (visual or tactile). Therefore, we measured brain activity by functional magnetic resonance imaging while healthy subjects memorized and reproduced auditory and visual rhythmic information. The inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum exhibited significant activations during both encoding and retrieving rhythm information. In addition, most of these areas exhibited significant activation also during the maintenance of rhythm information. All of these regions functioned in the processing of auditory and visual rhythms. The bilateral inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum are thought to be essential for motor control. When we listen to a certain rhythm, we are often stimulated to move our body, which suggests the existence of a strong interaction between rhythm processing and the motor system. Here, we propose that rhythm information may be represented and retained as information about bodily movements in the supra-modal motor brain system. Copyright © 2012 Elsevier Inc. All rights reserved.

Photoperiodism and circadian rhythms in relation to the hazards of environmental pollutants

International Nuclear Information System (INIS)

Attia, A.M.; Ali, M.M.; Abdou, M.M.

1999-01-01

The duration, intensity and wavelengths of light to which vertebrates and invertebrates are exposed vary widely over a 24-hour period as well as throughout the year. Species, by means of their behavioral patterns, differentially control in part the photoperiodic environment to which they are exposed. It is essential that mammals, probably including humans, adjust their physiology with changes in the makeup of the photoperiod. Numerous body functions undergo variations recurring at about 24-hour intervals in the presence or absence of known environmental changes with similar periods. This applies to continuos but rhythmic phenomena, with a peak and trough repeating itself every 24-hours, as well as to discrete events occurring about once a day. The time intervals separating these consecutive periodic events are similar but often not identical. Such periods are called circadian. Rhythms have been reported in cell growth, hormonal levels, and so on. Rhythms are generally resistant to a variety of chemical substances including stimulants and depressants. photoperiodism and circadian rhythms, in relation to the hazardous effects of environmental pollutants, as pesticides; which may directly or indirectly affect or alter physiologocal processes in living things, are summarized

Basic Principles of Interpersonal Social Rhythm Therapy in Bipolar Disorder

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Gokben Hizli Sayar

2014-08-01

Full Text Available Interpersonal Social Rhythm Therapy is a psychotherapy modality that helps the patient recognize the relationship between disruptions in social rhythms and the onset of previous episodes of psychiatric disorders. It uses psychoeducation and behavioral techniques to maintain social rhythm and sleep/wake regularity. It is closely related to and ldquo;social zeitgeber theory and rdquo; that emphasizes the importance that social rhythm regularity may play in synchronization of circadian rhythms in individuals with or at risk for bipolar spectrum disorders. Interpersonal and social rhythm therapy have been shown to stabilize social rhythms and enhance course and outcome in bipolar disorder. This review focuses on the theoretical principles and the basic steps of interpersonal and social rhythm therapy as a psychotherapy approach in bipolar disorder. PubMed, Scopus, Google Scholar databases were searched without temporal restriction. Search terms included interpersonal social rhythm therapy, bipolar, mood disorders. Abstracts were reviewed for relevance, and randomized controlled trials of interpersonal and social rhythm therapy in bipolar disorder selected. These researches also summarized on the final part of this review. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 438-446

Circadian Rhythms

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 11. Circadian Rhythms ... M Vaze1 Vijay Kumar Sharma1. Chronobiology Laboratory Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, PO Box 6436, Bangalore 560 064, India.

Circadian Rhythms

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Circadian Rhythms: Why do ... Nikhil Vijay Kumar Sharma1. Chronobiology Laboratory Evolutionary and Organismal Biology Unit Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, PO Box 6436, Bangalore 560 064, India.

Daily Rhythms in Mobile Telephone Communication.

Science.gov (United States)

Aledavood, Talayeh; López, Eduardo; Roberts, Sam G B; Reed-Tsochas, Felix; Moro, Esteban; Dunbar, Robin I M; Saramäki, Jari

2015-01-01

Circadian rhythms are known to be important drivers of human activity and the recent availability of electronic records of human behaviour has provided fine-grained data of temporal patterns of activity on a large scale. Further, questionnaire studies have identified important individual differences in circadian rhythms, with people broadly categorised into morning-like or evening-like individuals. However, little is known about the social aspects of these circadian rhythms, or how they vary across individuals. In this study we use a unique 18-month dataset that combines mobile phone calls and questionnaire data to examine individual differences in the daily rhythms of mobile phone activity. We demonstrate clear individual differences in daily patterns of phone calls, and show that these individual differences are persistent despite a high degree of turnover in the individuals' social networks. Further, women's calls were longer than men's calls, especially during the evening and at night, and these calls were typically focused on a small number of emotionally intense relationships. These results demonstrate that individual differences in circadian rhythms are not just related to broad patterns of morningness and eveningness, but have a strong social component, in directing phone calls to specific individuals at specific times of day.

Ischemic stroke destabilizes circadian rhythms

Directory of Open Access Journals (Sweden)

Borjigin Jimo

2008-10-01

Full Text Available Abstract Background The central circadian pacemaker is a remarkably robust regulator of daily rhythmic variations of cardiovascular, endocrine, and neural physiology. Environmental lighting conditions are powerful modulators of circadian rhythms, but regulation of circadian rhythms by disease states is less clear. Here, we examine the effect of ischemic stroke on circadian rhythms in rats using high-resolution pineal microdialysis. Methods Rats were housed in LD 12:12 h conditions and monitored by pineal microdialysis to determine baseline melatonin timing profiles. After demonstration that the circadian expression of melatonin was at steady state, rats were subjected to experimental stroke using two-hour intralumenal filament occlusion of the middle cerebral artery. The animals were returned to their cages, and melatonin monitoring was resumed. The timing of onset, offset, and duration of melatonin secretion were calculated before and after stroke to determine changes in circadian rhythms of melatonin secretion. At the end of the monitoring period, brains were analyzed to determine infarct volume. Results Rats demonstrated immediate shifts in melatonin timing after stroke. We observed a broad range of perturbations in melatonin timing in subsequent days, with rats exhibiting onset/offset patterns which included: advance/advance, advance/delay, delay/advance, and delay/delay. Melatonin rhythms displayed prolonged instability several days after stroke, with a majority of rats showing a day-to-day alternation between advance and delay in melatonin onset and duration. Duration of melatonin secretion changed in response to stroke, and this change was strongly determined by the shift in melatonin onset time. There was no correlation between infarct size and the direction or amplitude of melatonin phase shifting. Conclusion This is the first demonstration that stroke induces immediate changes in the timing of pineal melatonin secretion, indicating

Monkey Lipsmacking Develops Like the Human Speech Rhythm

Science.gov (United States)

Morrill, Ryan J.; Paukner, Annika; Ferrari, Pier F.; Ghazanfar, Asif A.

2012-01-01

Across all languages studied to date, audiovisual speech exhibits a consistent rhythmic structure. This rhythm is critical to speech perception. Some have suggested that the speech rhythm evolved "de novo" in humans. An alternative account--the one we explored here--is that the rhythm of speech evolved through the modification of rhythmic facial…

CRISPR/Cas9 and active genetics-based trans-species replacement of the endogenous Drosophila kni-L2 CRM reveals unexpected complexity.

Science.gov (United States)

Xu, Xiang-Ru Shannon; Gantz, Valentino Matteo; Siomava, Natalia; Bier, Ethan

2017-12-23

The knirps ( kni ) locus encodes transcription factors required for induction of the L2 wing vein in Drosophila . Here, we employ diverse CRISPR/Cas9 genome editing tools to generate a series of targeted lesions within the endogenous cis-regulatory module (CRM) required for kni expression in the L2 vein primordium. Phenotypic analysis of these ' in locus ' mutations based on both expression of Kni protein and adult wing phenotypes, reveals novel unexpected features of L2-CRM function including evidence for a chromosome pairing-dependent process that promotes transcription. We also demonstrate that self-propagating active genetic elements (CopyCat elements) can efficiently delete and replace the L2-CRM with orthologous sequences from other divergent fly species. Wing vein phenotypes resulting from these trans-species enhancer replacements parallel features of the respective donor fly species. This highly sensitive phenotypic readout of enhancer function in a native genomic context reveals novel features of CRM function undetected by traditional reporter gene analysis. © 2017, Xu et al.

A carnivore species (Canis familiaris) expresses circadian melatonin rhythm in the peripheral blood and melatonin receptors in the brain

International Nuclear Information System (INIS)

Stankov, B.; Moeller, M.; Lucini, V.; Capsono, S.; Fraschini, F.

1994-01-01

Dogs kept under controlled photoperiodic conditions of 12h light and 12h dark expressed a clear diurnal melatonin rhythm in the peripheral blood, with a swift peak restricted to the late part of the scotophase. The highest density of high-affinity, G-protein-linked 2-[ 125 I]iodomelatonin binding sites was found in the pars tuberalis of the pituitary gland. Binding sites were found also in the pars distalis, and light microscopy/high-resolution autoradiography showed that binding was located exclusively over the chromophobe and basophilic cells forming the adenopituitary zona tuberalis, well developed in the species, and extending into the gland as a continuation of pars tuberalis. Cords of basophilic cells located in the pars distalis proper also expressed high receptor density. Quantitative autoradiography inhibition experiments revealed that the apparent melatonin inhibitory constant in all those areas was around 0.1 nmol/l, which is a physiologically appropriate value considering the peripheral blood melatonin levels. Co-incubation with guanosine 3-thiotriphosphate led to a consequential decrease in the binding density. Collectively, these data show that the dog possesses all the prerequisites for an efficient network adapted to photoperiodic time measurements. A circadian melatonin signal in the peripheral blood and an apparently functional readout receptor system located in key positions within the brain are both present in this species. 43 refs. 6 figs., 1 tabs

Mu rhythm desynchronization by tongue thrust observation

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Kotoe eSakihara

2015-09-01

Full Text Available We aimed to investigate the mu rhythm in the sensorimotor area during tongue thrust observation and to obtain an answer to the question as to how subtle non-verbal orofacial movement observation activates the sensorimotor area. Ten healthy volunteers performed finger tap execution, tongue thrust execution, and tongue thrust observation. The electroencephalogram was recorded from 128 electrodes placed on the scalp, and regions of interest were set at sensorimotor areas. The event-related desynchronization (ERD and event-related synchronization (ERS for the mu rhythm (8–13 Hz and beta (13−25 Hz bands were measured. Tongue thrust observation induced mu rhythm ERD, and the ERD was detected at the left hemisphere regardless whether the observed tongue thrust was toward the left or right. Mu rhythm ERD was also recorded during tongue thrust execution. However, temporal analysis revealed that the ERD associated with tongue thrust observation preceded that associated with execution by approximately 2 s. Tongue thrust observation induces mu rhythm ERD in sensorimotor cortex with left hemispheric dominance.

Are endogenous feline leukemia viruses really endogenous?

Science.gov (United States)

Stewart, H; Jarrett, O; Hosie, M J; Willett, B J

2011-10-15

Full length endogenous feline leukemia virus (FeLV) proviruses exist within the genomes of many breeds of domestic cat raising the possibility that they may also exist in a transmissible exogenous form. Such viruses would share receptor usage with the recombinant FeLV-B subgroup, a viral subgroup that arises in vivo by recombination between exogenous subgroup A virus (FeLV-A) and endogenous FeLV. Accordingly, all isolates of FeLV-B made to date have contained a "helper" FeLV-A, consistent with their recombinatorial origin. In order to assess whether endogenous viruses are transmitted between cats, we examined primary isolates of FeLV for which the viral subgroup had been determined for the presence of a subgroup B virus that lacked an FeLV-A. Here we describe the identification of two primary field isolates of FeLV (2518 and 4314) that appeared to contain subgroup B virus only by classical interference assays, raising the possibility of between-host transmission of endogenous FeLV. Sequencing of the env gene and U3 region of the 3' long terminal repeat (LTR) confirmed that both viral genomes contained endogenous viral env genes. However the viral 3' LTRs appeared exogenous in origin with a putative 3' recombination breakpoint residing at the 3' end of the env gene. Further, the FeLV-2518 virions also co-packaged a truncated FeLV-A genome containing a defective env gene, termed FeLV-2518(A) whilst no helper subgroup A viral genome was detected in virions of FeLV-4314. The acquisition of an exogenous LTR by the endogenous FeLV in 4314 may have allowed a recombinant FeLV variant to outgrow an exogenous FeLV-A virus that was presumably present during first infection. Given time, a similar evolution may also occur within the 2518 isolate. The data suggest that endogenous FeLVs may be mobilised by acquisition of exogenous LTRs yielding novel viruses that type biologically as FeLV-B. Copyright © 2011 Elsevier B.V. All rights reserved.

‘Ragged Time’ in Intra-panel Comics Rhythms

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Corry Shores

2016-07-01

Full Text Available A phenomenological method of comics analysis can be useful when we need to uncover the structural features of the comics experience itself. One fruitful application would be in the study of irregular intra-panel rhythms, where the temporalized divisions are not visibly indicated but rather are only experienced. By means of Gilles Deleuze’s notion of rhythmic repetition and his elaboration of it through Olivier Messiaen’s theory of ‘kinetic’ rhythm, we will formulate a conception of visual rhythm as being based on metrical irregularity. We further explicate this concept of irregular rhythm by drawing upon the notion of ‘ragged time’ in the early jazz musical form, ragtime. We finally test its usefulness by examining how the ‘jazzy’ rhythms of Cubist-styled panels by Art Spiegelman and Mary Fleener generate an experience of ragged time.

Endogenous antipyretics.

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Roth, Joachim

2006-09-01

The febrile increase of body temperature is regarded as a component of the complex host response to infection or inflammation that accompanies the activation of the immune system. Late phases of fever appear mediated by pro-inflammatory cytokines called endogenous pyrogens. The rise of body temperature is beneficial because it accelerates several components of the activated immune system. To prevent an excessive and dangerous rise of body temperature the febrile response is controlled, limited in strength and duration, and sometimes even prevented by the actions of endogenous antipyretic substances liberated systemically or within the brain during fever. In most cases the antipyretic effects are achieved by an inhibitory influence on the formation or action of endogenous pyrogens, or by effects on neuronal thermoregulatory circuits that are activated during fever. Endogenous antipyretic substances include steroid hormones, neuropeptides, cytokines and other molecules. It is the purpose of this review to consider the current state in the research on endogenous antipyretic systems.

The epigenetic alterations of endogenous retroelements in aging.

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Cardelli, Maurizio

2018-02-16

Endogenous retroelements, transposons that mobilize through RNA intermediates, include some of the most abundant repetitive sequences of the human genome, such as Alu and LINE-1 sequences, and human endogenous retroviruses. Recent discoveries demonstrate that these mobile genetic elements not only act as intragenomic parasites, but also exert regulatory roles in living cells. The risk of genomic instability represented by endogenous retroelements is normally counteracted by a series of epigenetic control mechanisms which include, among the most important, CpG DNA methylation. Indeed, most of the genomic CpG sites subjected to DNA methylation in the nuclear DNA are carried by these repetitive elements. As other parts of the genome, endogenous retroelements and other transposable elements are subjected to deep epigenetic alterations during aging, repeatedly observed in the context of organismal and cellular senescence, in human and other species. This review summarizes the current status of knowledge about the epigenetic alterations occurring in this large, non-genic portion of the genome in aging and age-related conditions, with a focus on the causes and the possible functional consequences of these alterations. Copyright © 2018 Elsevier B.V. All rights reserved.

Combining Semi-Endogenous and Fully Endogenous Growth: a Generalization.

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Cozzi, Guido

2017-01-01

This paper shows that combining the semi-endogenous and the fully endogenous growth mechanisms with a general CES aggregator, either growth process can prevail in the balanced growth path depending on their degree of complementarity/substitutability. Policy-induced long-run economic switches to the fully endogenous steady state as the R&D employment ratio surpasses a positive threshold are possible if the two growth engines are gross substitutes.

Human endogenous retrovirus-R (ERV 3) env-like antigens ...

African Journals Online (AJOL)

Background: A substantial component of the vertebrate genome comprise of retrovirusrelated sequences named as endogenous retroviruses (ERVs). The role of these ERVrelated sequences in the biological processes of the host species is still unknown. However, they have been associated with tumourigenesis, ...

Mobilization of endogenous retroviruses in mice after infection with an exogenous retrovirus.

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Evans, Leonard H; Alamgir, A S M; Owens, Nick; Weber, Nick; Virtaneva, Kimmo; Barbian, Kent; Babar, Amenah; Malik, Frank; Rosenke, Kyle

2009-03-01

Mammalian genomes harbor a large number of retroviral elements acquired as germ line insertions during evolution. Although many of the endogenous retroviruses are defective, several contain one or more intact viral genes that are expressed under certain physiological or pathological conditions. This is true of the endogenous polytropic retroviruses that generate recombinant polytropic murine leukemia viruses (MuLVs). In these recombinants the env gene sequences of exogenous ecotropic MuLVs are replaced with env gene sequences from an endogenous polytropic retrovirus. Although replication-competent endogenous polytropic retroviruses have not been observed, the recombinant polytropic viruses are capable of replicating in numerous species. Recombination occurs during reverse transcription of a virion RNA heterodimer comprised of an RNA transcript from an endogenous polytropic virus and an RNA transcript from an exogenous ecotropic MuLV RNA. It is possible that homodimers corresponding to two full-length endogenous RNA genomes are also packaged. Thus, infection by an exogenous virus may result not only in recombination with endogenous sequences, but also in the mobilization of complete endogenous retrovirus genomes via pseudotyping within exogenous retroviral virions. We report that the infection of mice with an ecotropic virus results in pseudotyping of intact endogenous viruses that have not undergone recombination. The endogenous retroviruses infect and are integrated into target cell genomes and subsequently replicate and spread as pseudotyped viruses. The mobilization of endogenous retroviruses upon infection with an exogenous retrovirus may represent a major interaction of exogenous retroviruses with endogenous retroviruses and may have profound effects on the pathogenicity of retroviral infections.

A Reliable Method for Rhythm Analysis during Cardiopulmonary Resuscitation

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U. Ayala

2014-01-01

Full Text Available Interruptions in cardiopulmonary resuscitation (CPR compromise defibrillation success. However, CPR must be interrupted to analyze the rhythm because although current methods for rhythm analysis during CPR have high sensitivity for shockable rhythms, the specificity for nonshockable rhythms is still too low. This paper introduces a new approach to rhythm analysis during CPR that combines two strategies: a state-of-the-art CPR artifact suppression filter and a shock advice algorithm (SAA designed to optimally classify the filtered signal. Emphasis is on designing an algorithm with high specificity. The SAA includes a detector for low electrical activity rhythms to increase the specificity, and a shock/no-shock decision algorithm based on a support vector machine classifier using slope and frequency features. For this study, 1185 shockable and 6482 nonshockable 9-s segments corrupted by CPR artifacts were obtained from 247 patients suffering out-of-hospital cardiac arrest. The segments were split into a training and a test set. For the test set, the sensitivity and specificity for rhythm analysis during CPR were 91.0% and 96.6%, respectively. This new approach shows an important increase in specificity without compromising the sensitivity when compared to previous studies.

Fluctuation of biological rhythm in finger tapping

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Yoshinaga, H.; Miyazima, S.; Mitake, S.

2000-06-01

By analyzing biological rhythms obtained from finger tapping, we have investigated the differences of two biological rhythms between healthy and handicapped persons caused by Parkinson, brain infraction, car accident and so on. In this study, we have observed the motion of handedness of all subjects and obtained a slope a which characterizes a power-law relation between frequency and amplitude of finger-tapping rhythm. From our results, we have estimated that the slope a=0.06 is a rough criterion in order to distinguish healthy and handicapped persons.

Methodic of perfection of higher pedagogical educational establishments girl students’ rhythm

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A.N. Kolumbet

2016-06-01

Full Text Available Purpose: to study influence of methodic of rhythm perfection on girl students’ coordination abilities. Material: in the research 264 girl students participated. We assessed individual and collective rhythm, internal and external motor rhythm; rhythm in exercises with musical accompaniment. Results: we have determined that creative motor tasks require variable conditions for their realization. We have proved demand in appropriate criteria for their assessment. It is noted that there is a demand in development of rhythm, considering its main kinds and manifestations, which are formed with some peculiarities. Individual rhythm is determined by activation of attention and its level. It is perfected more successfully rather with stimulated development than with natural. It was found that with age the character of natural progressing of rhythm preserves. Conclusions: it is recommended to develop rhythm in compliance with its kinds and manifestations. Progressing and perfection of rhythm is a long lasted process and shall be realized during all period of girl students’ studying. Such approach forms girl students’ demand in finding of purposeful motor rhythm in all their new motor actions. It ensures optimality of their fulfillment.

Polymorphic integrations of an endogenous gammaretrovirus in the mule deer genome.

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Elleder, Daniel; Kim, Oekyung; Padhi, Abinash; Bankert, Jason G; Simeonov, Ivan; Schuster, Stephan C; Wittekindt, Nicola E; Motameny, Susanne; Poss, Mary

2012-03-01

Endogenous retroviruses constitute a significant genomic fraction in all mammalian species. Typically they are evolutionarily old and fixed in the host species population. Here we report on a novel endogenous gammaretrovirus (CrERVγ; for cervid endogenous gammaretrovirus) in the mule deer (Odocoileus hemionus) that is insertionally polymorphic among individuals from the same geographical location, suggesting that it has a more recent evolutionary origin. Using PCR-based methods, we identified seven CrERVγ proviruses and demonstrated that they show various levels of insertional polymorphism in mule deer individuals. One CrERVγ provirus was detected in all mule deer sampled but was absent from white-tailed deer, indicating that this virus originally integrated after the split of the two species, which occurred approximately one million years ago. There are, on average, 100 CrERVγ copies in the mule deer genome based on quantitative PCR analysis. A CrERVγ provirus was sequenced and contained intact open reading frames (ORFs) for three virus genes. Transcripts were identified covering the entire provirus. CrERVγ forms a distinct branch of the gammaretrovirus phylogeny, with the closest relatives of CrERVγ being endogenous gammaretroviruses from sheep and pig. We demonstrated that white-tailed deer (Odocoileus virginianus) and elk (Cervus canadensis) DNA contain proviruses that are closely related to mule deer CrERVγ in a conserved region of pol; more distantly related sequences can be identified in the genome of another member of the Cervidae, the muntjac (Muntiacus muntjak). The discovery of a novel transcriptionally active and insertionally polymorphic retrovirus in mammals could provide a useful model system to study the dynamic interaction between the host genome and an invading retrovirus.

Interactive Rhythm Learning System by Combining Tablet Computers and Robots

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Chien-Hsing Chou

2017-03-01

Full Text Available This study proposes a percussion learning device that combines tablet computers and robots. This device comprises two systems: a rhythm teaching system, in which users can compose and practice rhythms by using a tablet computer, and a robot performance system. First, teachers compose the rhythm training contents on the tablet computer. Then, the learners practice these percussion exercises by using the tablet computer and a small drum set. The teaching system provides a new and user-friendly score editing interface for composing a rhythm exercise. It also provides a rhythm rating function to facilitate percussion training for children and improve the stability of rhythmic beating. To encourage children to practice percussion exercises, a robotic performance system is used to interact with the children; this system can perform percussion exercises for students to listen to and then help them practice the exercise. This interaction enhances children’s interest and motivation to learn and practice rhythm exercises. The results of experimental course and field trials reveal that the proposed system not only increases students’ interest and efficiency in learning but also helps them in understanding musical rhythms through interaction and composing simple rhythms.

Circadian rhythm in idiopathic normal pressure hydrocephalus.

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Eleftheriou, Andreas; Ulander, Martin; Lundin, Fredrik

2018-01-01

The pathogenesis of idiopathic normal pressure hydrocephalus (iNPH) takes place in structures close to the cerebral ventricular system. Suprachiasmatic nucleus (SCN), situated close to the third ventricle, is involved in circadian rhythm. Diurnal disturbances are well-known in demented patients. The cognitive decline in iNPH is potentially reversible after a shunt operation. Diurnal rhythm has never been studied in iNPH. We hypothesize that there is a disturbance of circadian rhythm in iNPH-patients and the aim was to study any changes of the diurnal rhythm (mesor and circadian period) as well as any changes of the diurnal amplitude and acrophase of the activity in iNPH-patients before and after a shunt operation. Twenty consecutive iNPH-patients fulfilling the criteria of the American iNPH-guidelines, 9 males and 11 females, mean age 73 (49-81) years were included. The patients underwent a pre-operative clinical work-up including 10m walk time (w10mt) steps (w10ms), TUG-time (TUGt) and steps (TUGs) and for cognitive function an MMSE score was measured. In order to receive circadian rhythm data actigraphic recordings were performed using the SenseWear 2 (BodyMedia Inc Pittsburgh, PA, USA) actigraph. Cosinor analyses of accelerometry data were performed in "R" using non-linear regression with Levenburg- Marquardt estimation. Pre- and post-operative data regarding mesor, amplitude and circadian period were compared using Wilcoxon-Mann-Whitney test for paired data. Twenty patients were evaluated before and three month post-operatively. Motor function (w10mt, w10ms, TUGt, TUGs) was significantly improved while MMSE was not significantly changed. Actigraphic measurements (mesor, amplitude and circadian period) showed no significant changes after shunt operation. This is the first systematic study of circadian rhythm in iNPH-patients. We found no significant changes in circadian rhythm after shunt surgery. The conceptual idea of diurnal rhythm changes in hydrocephalus is

A circadian rhythm regulating hyphal melanization in Cercospora kikuchii.

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Bluhm, Burton H; Burnham, A Michele; Dunkle, Larry D

2010-01-01

Many metabolic and developmental processes in fungi are controlled by biological rhythms. Circadian rhythms approximate a daily (24 h) cycle and have been thoroughly studied in the model fungus, Neurospora crassa. However relatively few examples of true circadian rhythms have been documented among other filamentous fungi. In this study we describe a circadian rhythm underlying hyphal melanization in Cercospora kikuchii, an important pathogen of soybean. After growth in light or light : dark cycles, colonies transferred to darkness produced zonate bands of melanized hyphae interspersed with bands of hyaline hyphae. Rhythmic production of bands was remarkably persistent in the absence of external cues, lasting at least 7 d after transfer to darkness, and was compensated over a range of temperatures. As in N. crassa, blue light but not red light was sufficient to entrain the circadian rhythm in C. kikuchii, and a putative ortholog of white collar-1, one of the genes required for light responses in N. crassa, was identified in C. kikuchii. Circadian regulation of melanization is conserved in other members of the genus: Similar rhythms were identified in another field isolate of C. kikuchii as well as field isolates of C. beticola and C. sorghi, but not in wild-type strains of C. zeae-maydis or C. zeina. This report represents the first documented circadian rhythm among Dothideomycete fungi and provides a new opportunity to dissect the molecular basis of circadian rhythms among filamentous fungi.

Regulation of behavioral circadian rhythms and clock protein PER1 by the deubiquitinating enzyme USP2

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Yaoming Yang

2012-06-01

Endogenous 24-hour rhythms are generated by circadian clocks located in most tissues. The molecular clock mechanism is based on feedback loops involving clock genes and their protein products. Post-translational modifications, including ubiquitination, are important for regulating the clock feedback mechanism. Previous work has focused on the role of ubiquitin ligases in the clock mechanism. Here we show a role for the rhythmically-expressed deubiquitinating enzyme ubiquitin specific peptidase 2 (USP2 in clock function. Mice with a deletion of the Usp2 gene (Usp2 KO display a longer free-running period of locomotor activity rhythms and altered responses of the clock to light. This was associated with altered expression of clock genes in synchronized Usp2 KO mouse embryonic fibroblasts and increased levels of clock protein PERIOD1 (PER1. USP2 can be coimmunoprecipitated with several clock proteins but directly interacts specifically with PER1 and deubiquitinates it. Interestingly, this deubiquitination does not alter PER1 stability. Taken together, our results identify USP2 as a new core component of the clock machinery and demonstrate a role for deubiquitination in the regulation of the circadian clock, both at the level of the core pacemaker and its response to external cues.

Respiratory ultradian rhythms of mean and low frequencies: a comparative physiological approach.

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Stupfel, M; Pletan, Y

1983-01-01

Recent developments in human rhythmic respiratory pathology lead to this review of the literature for ultradian rhythms of middle and low frequencies, that is having periods longer than the usual respiratory rates, whose periods are seconds or fractions of seconds. Ultradian respiratory movements for respiratory periods (5 less than tau less than 50 min) have been reported in many species of small laboratory animals (mice, rats, guinea-pigs, rabbits, quails). Long-period respiratory rates (20 less than tau less than 90 min) have been found in human fetuses and infants. But they are more difficult to detect in human adults, except during sleep where they have been related to REM and NONREM activities. These respiratory rhythms of middle and low frequencies are supposed to result from dissipative energy structures related to surface-volume relationships, with interlocking chemical clocks, and to be relevant to a basic rest-activity cycle.

Circadian rhythm and sleep influences on digestive physiology and disorders

OpenAIRE

Vaughn, Bradley; Rotolo,Sean; Roth,Heidi

2014-01-01

Bradley V Vaughn, Sean Rotolo, Heidi L Roth Division of Sleep Medicine, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Abstract: Circadian rhythms and sleep influence a variety of physiological functions, including the digestive system. The digestive system also has intrinsic rhythms that interact dynamically with circadian rhythms. New advances in understanding the interaction of these rhythms and sleep provide the prospect of evaluating their...

A Statistical Analysis of Rhythm Patterns in Ghaleb Dehlavi’s Sonnets

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M. Ghazanfari

Full Text Available Ghaleb Dehlavi is considered as the best-known 13th century Indian poet. Also a writer and researcher, he was a Muslim originally from Touran with Eibak Turk ancestors. He was a pioneer of new styles in Urdu poetry. His poems are written in Urdu as well as Persian. His elaborate prose apart, Dehlavi’s odes and lyrics denote the poet’s noble thoughts and lofty nature. In spite of such traits and amazing proficiency in writing Persian poems, though a non-Persian speaker, the man has remained unknown or ignored in Iran. The present paper seeks to make orientations to Ghaleb Dehlavi by examining the rhythm patterns of his sonnets.Making references to the Indian style, the paper offers a typology and a computational account of rhythms as used in Ghaleb’s poems. It is found that 20 different rhythms are employed to versify a totality of 334 sonnets of which 85 percent are in only six rhythms. These six happen to be so frequently used in Persian too.The most frequent rhythm used by Ghaleb is ‘mafoolon faelaton mafaelon faelon’. Highly employed in Persian sonnets too, this rhythm is so capable of expressing the intended concepts. ‘Mafaelon faalaton mafaelna falon’ is another rhythm of his interest used more frequently in his anthology than in Persian poetry. The rhythm ‘mafoolon mafaelon mafaelon faolon’, vastly used by Saadi and Hafiz, also appeals to Ghaleb.Ghaleb’s application of the octave rhythms ‘raml’ and ‘hazj’, which sound so grave in Persian, suggests his tendency for the Indian style in poetry. However, the rise and fall in the frequency of certain rhythms in his anthology may be viewed as an indication of a retreat from his previously practiced literary style. The only rare rhythm in Ghaleb’s poems is ‘faelaton mafoolon faelaton mafoolon’ first tried in Attar’s sonnets. This rhythm has also been tried by Hafiz, Khajou Kermani, Saeb, Kalim, Feyz Kashani, and Bidel Dehlavi. The rhythm has given a stylistic

On the classification and evolution of endogenous retrovirus: human endogenous retroviruses may not be 'human' after all.

Science.gov (United States)

Escalera-Zamudio, Marina; Greenwood, Alex D

2016-01-01

Retroviruses, as part of their replication cycle, become integrated into the genome of their host. When this occurs in the germline the integrated proviruses can become an endogenous retrovirus (ERV) which may eventually become fixed in the population. ERVs are present in the genomes of all vertebrates including humans, where more than 50 groups of human endogenous retrovirus (HERVs) have been described within the last 30 years. Despite state-of-the-art genomic tools available for retroviral discovery and the large number of retroviral sequences described to date, there are still gaps in understanding retroviral macroevolutionary patterns and host-retrovirus interactions and a lack of a coherent systematic classification particularly for HERVs. Here, we discuss the current knowledge on ERV (and HERV) classification, distribution and origins focusing on the role of cross-species transmission in retroviral diversity. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Development of cortisol circadian rhythm in infancy.

NARCIS (Netherlands)

Weerth, C. de; Zijl, R.H.

2003-01-01

BACKGROUND AND AIMS: Cortisol is the final product of the hypothalamus-pituitary-adrenal (HPA) axis. It is secreted in a pulsatile fashion that displays a circadian rhythm. Infants are born without a circadian rhythm in cortisol and they acquire it during their first year of life. Studies do not

Mother-infant circadian rhythm: development of individual patterns and dyadic synchrony.

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Thomas, Karen A; Burr, Robert L; Spieker, Susan; Lee, Jungeun; Chen, Jessica

2014-12-01

Mutual circadian rhythm is an early and essential component in the development of maternal-infant physiological synchrony. The aim of this to examine the longitudinal pattern of maternal-infant circadian rhythm and rhythm synchrony as measured by rhythm parameters. In-home dyadic actigraphy monitoring at infant age 4, 8, and 12 weeks. Forty-three healthy mother-infant pairs. Circadian parameters derived from cosinor and non-parametric analysis including mesor, magnitude, acrophase, L5 and M10 midpoints (midpoint of lowest 5 and highest 10h of activity), amplitude, interdaily stability (IS), and intradaily variability (IV). Mothers experienced early disruption of circadian rhythm, with re-establishment of rhythm over time. Significant time effects were noted in increasing maternal magnitude, amplitude, and IS and decreasing IV (pcircadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (pcircadian rhythm. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Circadian rhythms in cognitive performance: implications for neuropsychological assessment

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Valdez P

2012-12-01

Full Text Available Pablo Valdez, Candelaria Ramírez, Aída GarcíaLaboratory of Psychophysiology, School of Psychology, University of Nuevo León, Monterrey, Nuevo León, MéxicoAbstract: Circadian variations have been found in human performance, including the efficiency to execute many tasks, such as sensory, motor, reaction time, time estimation, memory, verbal, arithmetic calculations, and simulated driving tasks. Performance increases during the day and decreases during the night. Circadian rhythms have been found in three basic neuropsychological processes (attention, working memory, and executive functions, which may explain oscillations in the performance of many tasks. The time course of circadian rhythms in cognitive performance may be modified significantly in patients with brain disorders, due to chronotype, age, alterations of the circadian rhythm, sleep deprivation, type of disorder, and medication. This review analyzes the recent results on circadian rhythms in cognitive performance, as well as the implications of these rhythms for the neuropsychological assessment of patients with brain disorders such as traumatic head injury, stroke, dementia, developmental disorders, and psychiatric disorders.Keywords: human circadian rhythms, cognitive performance, neuropsychological assessment, attention, working memory, executive functions

Endogenous fertility and development traps with endogenous lifetime

OpenAIRE

Fanti, Luciano; Gori, Luca

2010-01-01

We extend the literature on endogenous lifetime and economic growth by Chakraborty (2004) and Bunzel and Qiao (2005) to endogenous fertility. We show that development traps due to underinvestments in health cannot appear when fertility is an economic decision variable and the costs of children are represented by a constant fraction of the parents' income used for their upbringing.

Endogenous Retrovirus 3 – History, Physiology, and Pathology

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Bustamante Rivera, Yomara Y.; Brütting, Christine; Schmidt, Caroline; Volkmer, Ines; Staege, Martin S.

2018-01-01

Endogenous viral elements (EVE) seem to be present in all eukaryotic genomes. The composition of EVE varies between different species. The endogenous retrovirus 3 (ERV3) is one of these elements that is present only in humans and other Catarrhini. Conservation of ERV3 in most of the investigated Catarrhini and the expression pattern in normal tissues suggest a putative physiological role of ERV3. On the other hand, ERV3 has been implicated in the pathogenesis of auto-immunity and cancer. In the present review we summarize knowledge about this interesting EVE. We propose the model that expression of ERV3 (and probably other EVE loci) under pathological conditions might be part of a metazoan SOS response. PMID:29379485

Endogenous Retrovirus 3 – History, Physiology, and Pathology

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Yomara Y. Bustamante Rivera

2018-01-01

Full Text Available Endogenous viral elements (EVE seem to be present in all eukaryotic genomes. The composition of EVE varies between different species. The endogenous retrovirus 3 (ERV3 is one of these elements that is present only in humans and other Catarrhini. Conservation of ERV3 in most of the investigated Catarrhini and the expression pattern in normal tissues suggest a putative physiological role of ERV3. On the other hand, ERV3 has been implicated in the pathogenesis of auto-immunity and cancer. In the present review we summarize knowledge about this interesting EVE. We propose the model that expression of ERV3 (and probably other EVE loci under pathological conditions might be part of a metazoan SOS response.

Further comparisons of endogenous pyrogens and leukocytic endogenous mediators.

Science.gov (United States)

Kampschmidt, R F; Upchurch, H F; Worthington, M L

1983-07-01

It was recently shown (Murphy et al., Infect. Immun. 34:177-183), that rabbit macrophages produce two biochemically and immunologically distinct endogenous pyrogens. One of these has or copurifies with substances having a molecular weight of 13,000 and a pI of 7.3. This protein was produced by blood monocytes or inflammatory cells elicited in 16-h rabbit peritoneal exudates. These acute peritoneal exudates were produced by the intraperitoneal injection of large volumes of saline containing shellfish glycogen. When the leukocytes in these exudates were washed and incubated at 37 degrees C in saline, they released an endogenous pyrogen. The injection of this pyrogen into rabbits, rats, or mice caused the biological manifestations which have been attributed to leukocytic endogenous mediator. These effects were increases in blood neutrophils, the lowering of plasma iron and zinc levels, and the increased synthesis of the acute-phase proteins. The other rabbit endogenous pyrogen seems to be a family of proteins with isoelectric points between 4.5 and 5.0. These proteins are produced by macrophages in the lung, liver, or in chronic peritoneal exudates. In these experiments, the lower-isoelectric-point endogenous pyrogens were produced by macrophages from the peritoneal cavity of rabbits that had been injected 4 days earlier with 50 ml of light mineral oil. These rabbit pyrogens were found to have leukocytic endogenous mediator activity in mice but to be completely inactive in rats. When injected into rabbits, these proteins produced fever, lowered plasma iron, increased blood neutrophils, but failed to elevate plasma fibrinogen.

Circadian rhythm and sleep influences on digestive physiology and disorders

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Vaughn BV

2014-09-01

Full Text Available Bradley V Vaughn, Sean Rotolo, Heidi L Roth Division of Sleep Medicine, Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Abstract: Circadian rhythms and sleep influence a variety of physiological functions, including the digestive system. The digestive system also has intrinsic rhythms that interact dynamically with circadian rhythms. New advances in understanding the interaction of these rhythms and sleep provide the prospect of evaluating their role in normal physiology and the link of their disruption to pathological conditions. Recent work has demonstrated that sleep and circadian factors influence appetite, nutrient absorption, and metabolism. Disruption of sleep and circadian rhythms may increase vulnerability to digestive disorders, including reflux, ulcers, inflammatory bowel issues, irritable bowel disease, and gastrointestinal cancer. As our knowledge of the link between circadian timing and gastrointestinal physiology grows, so do our opportunities to provide promising diagnostic and therapeutic approaches for gastrointestinal disorders. Keywords: digestion, digestive diseases, gastrointestinal reflux, sleep, circadian rhythm 

Alpha-band rhythm suppression during memory recall reflecting memory performance.

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Yokosawa, Koichi; Kimura, Keisuke; Chitose, Ryota; Momiki, Takuya; Kuriki, Shinya

2016-08-01

Alpha-band rhythm is thought to be involved in memory processes, similarly to other spontaneous brain rhythms. Ten right-handed healthy volunteers participated in our proposed sequential short-term memory task that provides a serial position effect in accuracy rate. We recorded alpha-band rhythms by magnetoencephalography during performance of the task and observed that the amplitude of the rhythm was suppressed dramatically in the memory recall period. The suppressed region was estimated to be in the occipital lobe, suggesting that alpha-band rhythm is suppressed by activation of the occipital attentional network. Additionally, the alpha-band suppression reflected accuracy rate, that is, the amplitude was suppressed more when recalling items with higher accuracy rate. The sensors with a significant correlation between alpha-band amplitude and accuracy rate were located widely from the frontal to occipital regions mainly in the right hemisphere. The results suggests that alpha-band rhythm is involved in memory recall and can be index of memory performance.

Analysis of Handwriting based on Rhythm Perception

Science.gov (United States)

Saito, Kazuya; Uchida, Masafumi; Nozawa, Akio

Humanity fluctuation was reported in some fields. In handwriting process, fluctuation appears on handwriting-velocity. In this report, we focused attention on human rhythm perception and analyzed fluctuation in handwriting process. As a result, 1/f noise related to rhythm perception and features may caused by Kahneman's capacity model were measured on handwriting process.

α-Syntrophin stabilizes catalase to reduce endogenous reactive oxygen species levels during myoblast differentiation.

Science.gov (United States)

Moon, Jae Yun; Choi, Su Jin; Heo, Cheol Ho; Kim, Hwan Myung; Kim, Hye Sun

2017-07-01

α-Syntrophin is a component of the dystrophin-glycoprotein complex that interacts with various intracellular signaling proteins in muscle cells. The α-syntrophin knock-down C2 cell line (SNKD), established by infecting lentivirus particles with α-syntrophin shRNA, is characterized by a defect in terminal differentiation and increase in cell death. Since myoblast differentiation is accompanied by intensive mitochondrial biogenesis, the generation of intracellular reactive oxygen species (ROS) is also increased during myogenesis. Two-photon microscopy imaging showed that excessive intracellular ROS accumulated during the differentiation of SNKD cells as compared with control cells. The formation of 4-hydroxynonenal adduct, a byproduct of lipid peroxidation during oxidative stress, significantly increased in differentiated SNKD myotubes and was dramatically reduced by epigallocatechin-3-gallate, a well-known ROS scavenger. Among antioxidant enzymes, catalase was significantly decreased during differentiation of SNKD cells without changes at the mRNA level. Of interest was the finding that the degradation of catalase was rescued by MG132, a proteasome inhibitor, in the SNKD cells. This study demonstrates a novel function of α-syntrophin. This protein plays an important role in the regulation of oxidative stress from endogenously generated ROS during myoblast differentiation by modulating the protein stability of catalase. © 2017 Federation of European Biochemical Societies.

Unexpected diversity in socially synchronized rhythms of shorebirds

NARCIS (Netherlands)

Bulla, Martin; Valcu, Mihai; Dokter, Adriaan M; Dondua, Alexei G; Kosztolányi, András; Helm, Barbara; Sandercock, Brett K; Casler, Bruce; Ens, Bruno J.; Spiegel, Caleb S; Hassell, Chris J; Küpper, Clemens; Minton, Clive; Burgas, Daniel; Lank, David B; Payer, David C; Loktionov, Egor Y; Nol, Erica; Kwon, Eunbi; Smith, Fletcher; Gates, H River; Vitnerová, Hana; Prüter, Hanna; Johnson, James A; St Clair, James J H; Lamarre, Jean-François; Rausch, Jennie; Reneerkens, Jeroen; Conklin, Jesse R; Burger, Joanna; Liebezeit, Joe; Bêty, Joël; Coleman, Jonathan T; Figuerola, Jordi; Hooijmeijer, Joslyn; Alves, José A; Smith, Joseph A M; Weidinger, Karel; Koivula, Kari; Gosbell, Ken; Exo, Klaus-Michael; Niles, Larry; Koloski, Laura; McKinnon, Laura; Praus, Libor; Klaassen, Marcel; Giroux, Marie-Andrée; Sládeček, Martin; Boldenow, Megan L; Goldstein, Michael I; Šálek, Miroslav; Senner, Nathan; Rönkä, Nelli; Lecomte, Nicolas; Gilg, Olivier; Vincze, Orsolya; Johnson, Oscar W; Smith, Paul A; Woodard, Paul F; Tomkovich, Pavel S; Battley, Phil F; Bentzen, Rebecca; Lanctot, Richard B; Porter, Ron; Saalfeld, Sarah T; Freeman, Scott; Brown, Stephen C; Yezerinac, Stephen; Székely, Tamás; Montalvo, Tomás; Piersma, Theunis; Loverti, Vanessa; Pakanen, Veli-Matti; Tijsen, Wim; Kempenaers, Bart

2016-01-01

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities

Reviewing the musical component of rhythm of "poetry" and the factors influencing it

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Ma’sumeh Ma’dankan

2017-04-01

Full Text Available ‘Rhythm’ is the most important component in the music of poetry. In this paper, in addition to defining rhythm, we have studied relative components which have most influence on the music of poetry. ‘Rhythm’ is the first common factor in different arts especially music and poetry. Poetry has always been along with rhythm. A short and complete definition of ‘rhythm’ is: “Rhythm is the balance resulting from sequence of letters or rhythms at certain limited times”.The most important factors affecting rhythm are: Proportion of syllables at prosodic rhythms: Every syllable has its special musical load at prosodic rhythms. It is clear that if each of them is mostly used at one rhythm, it will mostly and clearly show its own special state. Sequence of syllables at prosodic rhythms: Succession of long or short syllables because of their special vocal effect on rhythm is very effective on the musical quality of rhythm. Application of long syllable: The most the number of long syllables in a verse, the heavier will be the rhythm of the verse. Because in this way the number of syllables of every verse will be decreased and their temporal duration will be increased. Conformity of the end of words with the end of elements (space between words with space between elements: conformity of the end of words and elements because of the repeated sequence of an element highly strengthens the effect of that prosodic element at the mind of the listener. These constant and repeated scansions make the poem rhythmic and enrich its music. Making accidental or the second rhythm: one way for innovation and overcoming the natural music of a rhythm is making a special rhythm other than the main prosodic rhythm of poem by arranging the words in a special order in a way that it conforms to the other scansion of the same prosodic rhythm. Using regular space between words other than space of elements: sometimes the poet without using a different scansion of the

Chronotype and circadian rhythm in bipolar disorder: A systematic review.

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Melo, Matias C A; Abreu, Rafael L C; Linhares Neto, Vicente B; de Bruin, Pedro F C; de Bruin, Veralice M S

2017-08-01

Despite a complex relationship between mood, sleep and rhythm, the impact of circadian disruptions on bipolar disorder (BD) has not been clarified. The purpose of this systematic review was to define current evidence regarding chronotype and circadian rhythm patterns in BD patients. 42 studies were included, involving 3432 BD patients. Disruption of the biological rhythm was identified, even in drug-naïve BD patients and independently of mood status. Daily profiles of melatonin levels and cortisol indicated a delayed phase. Depression was more frequently associated with circadian alterations than euthymia. Few studies evaluated mania, demonstrating irregular rhythms. Evening type was more common in BD adults. Studies about the influence of chronotype on depressive symptoms showed conflicting results. Only one investigation observed the influences of chronotype in mania, revealing no significant association. Effects of psychoeducation and lithium on rhythm in BD patients were poorly studied, demonstrating no improvement of rhythm parameters. Studies about genetics are incipient. In conclusion, disruption in circadian rhythm and eveningness are common in BD. Prospective research evaluating the impact of circadian disruption on mood symptoms, metabolism, seasonality, the influence of age and the effects of mood stabilizers are needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Endogenous cellulases in animals: Isolation of β-1,4-endoglucanase genes from two species of plant-parasitic cyst nematodes

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Smant, Geert; Stokkermans, Jack P. W. G.; Yan, Yitang; de Boer, Jan M.; Baum, Thomas J.; Wang, Xiaohong; Hussey, Richard S.; Gommers, Fred J.; Henrissat, Bernard; Davis, Eric L.; Helder, Johannes; Schots, Arjen; Bakker, Jaap

1998-01-01

β-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing β-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the cyst nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37–44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3′ end precluded the EGases from being of bacterial origin. Cyst nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation. PMID:9560201

Circadian Sleep-Wake Rhythm of Older Adults with Intellectual Disabilities

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Maaskant, Marijke; van de Wouw, Ellen; van Wijck, Ruud; Evenhuis, Heleen M.; Echteld, Michael A.

2013-01-01

The circadian sleep-wake rhythm changes with aging, resulting in a more fragmented sleep-wake pattern. In individuals with intellectual disabilities (ID), brain structures regulating the sleep-wake rhythm might be affected. The aims of this study were to compare the sleep-wake rhythm of older adults with ID to that of older adults in the general…

Impaired endogenous nighttime melatonin secretion relates to intrarenal renin-angiotensin system activation and renal damage in patients with chronic kidney disease.

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Ishigaki, Sayaka; Ohashi, Naro; Isobe, Shinsuke; Tsuji, Naoko; Iwakura, Takamasa; Ono, Masafumi; Sakao, Yukitoshi; Tsuji, Takayuki; Kato, Akihiko; Miyajima, Hiroaki; Yasuda, Hideo

2016-12-01

Activation of the intrarenal renin-angiotensin system (RAS) plays a critical role in the pathophysiology of chronic kidney disease (CKD) and hypertension. The circadian rhythm of intrarenal RAS activation leads to renal damage and hypertension, which are associated with diurnal blood pressure (BP) variation. The activation of intrarenal RAS following reactive oxygen species (ROS) activation, sympathetic hyperactivity and nitric oxide (NO) inhibition leads to the development of renal damage. Melatonin is a hormone regulating the circadian rhythm, and has multiple functions such as anti-oxidant and anti-adrenergic effects and enhancement of NO bioavailability. Nocturnal melatonin concentrations are lower in CKD patients. However, it is not known if impaired endogenous melatonin secretion is related to BP, intrarenal RAS, or renal damage in CKD patients. We recruited 53 CKD patients and conducted 24-h ambulatory BP monitoring. urine was collected during the daytime and nighttime. We investigated the relationship among the melatonin metabolite urinary 6-sulphatoxymelatonin (U-aMT6s), BP, renal function, urinary angiotensinogen (U-AGT), and urinary albumin (U-Alb). Patients' U-aMT6s levels were significantly and negatively correlated with clinical parameters such as renal function, systolic BP, U-AGT, and U-Alb, during both day and night. Multiple regression analyses for U-aMT6s levels were performed using age, gender, renal function, and each parameter (BPs, U-AGT or U-Alb), at daytime and nighttime. U-aMT6s levels were significantly associated with U-AGT (β = -0.31, p = 0.044) and U-Alb (β = -0.25, p = 0.025) only at night. Impaired nighttime melatonin secretion may be associated with nighttime intrarenal RAS activation and renal damage in CKD patients.

Sensorimotor rhythm neurofeedback as adjunct therapy for Parkinson's disease.

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Philippens, Ingrid H C H M; Wubben, Jacqueline A; Vanwersch, Raymond A P; Estevao, Dave L; Tass, Peter A

2017-08-01

Neurofeedback may enhance compensatory brain mechanisms. EEG-based sensorimotor rhythm neurofeedback training was suggested to be beneficial in Parkinson's disease. In a placebo-controlled study in parkinsonian nonhuman primates we here show that sensorimotor rhythm neurofeedback training reduces MPTP-induced parkinsonian symptoms and both ON and OFF scores during classical L-DOPA treatment. Our findings encourage further development of sensorimotor rhythm neurofeedback training as adjunct therapy for Parkinson's disease which might help reduce L-DOPA-induced side effects.

Rhythms in the endocrine system of fish: a review.

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Cowan, Mairi; Azpeleta, Clara; López-Olmeda, Jose Fernando

2017-12-01

The environment which living organisms inhabit is not constant and many factors, such as light, temperature, and food availability, display cyclic and predictable variations. To adapt to these cyclic changes, animals present biological rhythms in many of their physiological variables, timing their functions to occur when the possibility of success is greatest. Among these variables, many endocrine factors have been described as displaying rhythms in vertebrates. The aim of the present review is to provide a thorough review of the existing knowledge on the rhythms of the endocrine system of fish by examining the hormones that show rhythmicity, how environmental factors control these rhythms and the variation in the responses of the endocrine system depending on the time of the day. We mainly focused on the hypothalamic-pituitary axis, which can be considered as the master axis of the endocrine system of vertebrates and regulates a great variety of functions, including reproduction, growth, metabolism, energy homeostasis, stress response, and osmoregulation. In addition, the rhythms of other hormones, such as melatonin and the factors, produced in the gastrointestinal system of fish are reviewed.

Neural responses to complex auditory rhythms: the role of attending

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Heather L Chapin

2010-12-01

Full Text Available The aim of this study was to explore the role of attention in pulse and meter perception using complex rhythms. We used a selective attention paradigm in which participants attended to either a complex auditory rhythm or a visually presented word list. Performance on a reproduction task was used to gauge whether participants were attending to the appropriate stimulus. We hypothesized that attention to complex rhythms – which contain no energy at the pulse frequency – would lead to activations in motor areas involved in pulse perception. Moreover, because multiple repetitions of a complex rhythm are needed to perceive a pulse, activations in pulse related areas would be seen only after sufficient time had elapsed for pulse perception to develop. Selective attention was also expected to modulate activity in sensory areas specific to the modality. We found that selective attention to rhythms led to increased BOLD responses in basal ganglia, and basal ganglia activity was observed only after the rhythms had cycled enough times for a stable pulse percept to develop. These observations suggest that attention is needed to recruit motor activations associated with the perception of pulse in complex rhythms. Moreover, attention to the auditory stimulus enhanced activity in an attentional sensory network including primary auditory, insula, anterior cingulate, and prefrontal cortex, and suppressed activity in sensory areas associated with attending to the visual stimulus.

The Rest-Activity Rhythm and Physical Activity in Early-Onset Dementia

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Hooghiemstra, A.M.; Eggermont, L.H.P.; Scheltens, P.; van der Flier, W.M.; Scherder, E.J.A.

2015-01-01

Background: A substantial part of elderly persons with dementia show rest-activity rhythm disturbances. The rest-activity rhythm is important to study in people with early-onset dementia (EOD) for rest-activity rhythm disturbances are predictive of institutionalization, and caregivers of young

Effects of Chronic Social Defeat Stress on Sleep and Circadian Rhythms Are Mitigated by Kappa-Opioid Receptor Antagonism.

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Wells, Audrey M; Ridener, Elysia; Bourbonais, Clinton A; Kim, Woori; Pantazopoulos, Harry; Carroll, F Ivy; Kim, Kwang-Soo; Cohen, Bruce M; Carlezon, William A

2017-08-09

Stress plays a critical role in the neurobiology of mood and anxiety disorders. Sleep and circadian rhythms are affected in many of these conditions. Here we examined the effects of chronic social defeat stress (CSDS), an ethological form of stress, on sleep and circadian rhythms. We exposed male mice implanted with wireless telemetry transmitters to a 10 day CSDS regimen known to produce anhedonia (a depressive-like effect) and social avoidance (an anxiety-like effect). EEG, EMG, body temperature, and locomotor activity data were collected continuously during the CSDS regimen and a 5 day recovery period. CSDS affected numerous endpoints, including paradoxical sleep (PS) and slow-wave sleep (SWS), as well as the circadian rhythmicity of body temperature and locomotor activity. The magnitude of the effects increased with repeated stress, and some changes (PS bouts, SWS time, body temperature, locomotor activity) persisted after the CSDS regimen had ended. CSDS also altered mRNA levels of the circadian rhythm-related gene mPer2 within brain areas that regulate motivation and emotion. Administration of the κ-opioid receptor (KOR) antagonist JDTic (30 mg/kg, i.p.) before CSDS reduced stress effects on both sleep and circadian rhythms, or hastened their recovery, and attenuated changes in mPer2 Our findings show that CSDS produces persistent disruptions in sleep and circadian rhythmicity, mimicking attributes of stress-related conditions as they appear in humans. The ability of KOR antagonists to mitigate these disruptions is consistent with previously reported antistress effects. Studying homologous endpoints across species may facilitate the development of improved treatments for psychiatric illness. SIGNIFICANCE STATEMENT Stress plays a critical role in the neurobiology of mood and anxiety disorders. We show that chronic social defeat stress in mice produces progressive alterations in sleep and circadian rhythms that resemble features of depression as it appears in

Educating the sense of rhythm in primary education students

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Silvia GRĂDINARU

2017-03-01

Full Text Available Background: Rhythm as a core element of complex coordination is the key to efficient moulding of motor skills specific to sports activities in curricula. Practicing physical exercise in a varied rhythm and tempo in primary school students moulds the skill of achieving correct movement basics (direction, span, coordination, and expressivity. The use of music in sports classes improves kinetics and vestibular sensitivity. The sense of rhythm and tempo are imperative criteria in vocational schools. Purpose: This paper aims to describe a pattern of means selected to develop the sense of rhythm and to allow movements in different sports branches with increased efficiency. Methods: The test battery was applied on a sample of 15 students from the 4th grade of the “Ion Vidu” National Arts College in Timisoara, Romania, aged 9-10 years, over an entire school year, using different rhythms and tempos during sports classes, which were later used in gymnastics, athletic events, and basketball. Results: Data recorded after the application tests, processed and interpreted confirms the proposed assumption and validates the motor contents used. Conclusions: Sense of rhythm is a component of coordinative capacity that is required to be educated from an early age. Rhythmic movements are easier to automate saving energy and motivating students to an active and conscious participation.

Implications of Circadian Rhythm in Dopamine and Mood Regulation.

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Kim, Jeongah; Jang, Sangwon; Choe, Han Kyoung; Chung, Sooyoung; Son, Gi Hoon; Kim, Kyungjin

2017-07-31

Mammalian physiology and behavior are regulated by an internal time-keeping system, referred to as circadian rhythm. The circadian timing system has a hierarchical organization composed of the master clock in the suprachiasmatic nucleus (SCN) and local clocks in extra-SCN brain regions and peripheral organs. The circadian clock molecular mechanism involves a network of transcription-translation feedback loops. In addition to the clinical association between circadian rhythm disruption and mood disorders, recent studies have suggested a molecular link between mood regulation and circadian rhythm. Specifically, genetic deletion of the circadian nuclear receptor Rev-erbα induces mania-like behavior caused by increased midbrain dopaminergic (DAergic) tone at dusk. The association between circadian rhythm and emotion-related behaviors can be applied to pathological conditions, including neurodegenerative diseases. In Parkinson's disease (PD), DAergic neurons in the substantia nigra pars compacta progressively degenerate leading to motor dysfunction. Patients with PD also exhibit non-motor symptoms, including sleep disorder and neuropsychiatric disorders. Thus, it is important to understand the mechanisms that link the molecular circadian clock and brain machinery in the regulation of emotional behaviors and related midbrain DAergic neuronal circuits in healthy and pathological states. This review summarizes the current literature regarding the association between circadian rhythm and mood regulation from a chronobiological perspective, and may provide insight into therapeutic approaches to target psychiatric symptoms in neurodegenerative diseases involving circadian rhythm dysfunction.

Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

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Li, Ying; Liu, Zengrong

MicroRNAs (miRNAs) interact with 3‧untranslated region (UTR) elements of target genes to regulate mRNA stability or translation, and play a crucial role in regulating many different biological processes. bantam, a conserved miRNA, is involved in several functions, such as regulating Drosophila growth and circadian rhythm. Recently, it has been discovered that bantam plays a crucial role in the core circadian pacemaker. In this paper, based on experimental observations, a detailed dynamical model of bantam-regulated circadian clock system is developed to show the post-transcriptional behaviors in the modulation of Drosophila circadian rhythm, in which the regulation of bantam is incorporated into a classical model. The dynamical behaviors of the model are consistent with the experimental observations, which shows that bantam is an important regulator of Drosophila circadian rhythm. The sensitivity analysis of parameters demonstrates that with the regulation of bantam the system is more sensitive to perturbations, indicating that bantam regulation makes it easier for the organism to modulate its period against the environmental perturbations. The effectiveness in rescuing locomotor activity rhythms of mutated flies shows that bantam is necessary for strong and sustained rhythms. In addition, the biological mechanisms of bantam regulation are analyzed, which may help us more clearly understand Drosophila circadian rhythm regulated by other miRNAs.

Effects of Resveratrol on Daily Rhythms of Locomotor Activity and Body Temperature in Young and Aged Grey Mouse Lemurs

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Fabien Pifferi

2013-01-01

Full Text Available In several species, resveratrol, a polyphenolic compound, activates sirtuin proteins implicated in the regulation of energy balance and biological clock processes. To demonstrate the effect of resveratrol on clock function in an aged primate, young and aged mouse lemurs (Microcebus murinus were studied over a 4-week dietary supplementation with resveratrol. Spontaneous locomotor activity and daily variations in body temperature were continuously recorded. Reduction in locomotor activity onset and changes in body temperature rhythm in resveratrol-supplemented aged animals suggest an improved synchronisation on the light-dark cycle. Resveratrol could be a good candidate to restore the circadian rhythms in the elderly.

Circadian Activity Rhythms, Time Urgency, and Achievement Concerns.

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Watts, Barbara L.

Many physiological and psychological processes fluctuate throughout the day in fairly stable, rhythmic patterns. The relationship between individual differences in circadian activity rhythms and a sense of time urgency were explored as well as a number of achievement-related variables. Undergraduates (N=308), whose circadian activity rhythms were…

Endogenous Lunar Volatiles

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McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Anand, M.; Boyce, J. W.; Burney, D.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Klima, R. L.; Magna, T.; Ni, P.; Steenstra, E.; Tartèse, R.; Vander Kaaden, K. E.

2018-04-01

This abstract discusses numerous outstanding questions on the topic of endogenous lunar volatiles that will need to be addressed in the coming years. Although substantial insights into endogenous lunar volatiles have been gained, more work remains.

Circadian Rhythm Sleep-Wake Disorders in Older Adults.

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Kim, Jee Hyun; Duffy, Jeanne F

2018-03-01

The timing, duration, and consolidation of sleep result from the interaction of the circadian timing system with a sleep-wake homeostatic process. When aligned and functioning optimally, this allows wakefulness throughout the day and a long consolidated sleep episode at night. Mismatch between the desired timing of sleep and the ability to fall and remain asleep is a hallmark of the circadian rhythm sleep-wake disorders. This article discusses changes in circadian regulation of sleep with aging; how age influences the prevalence, diagnosis, and treatment of circadian rhythm sleep-wake disorders; and how neurologic diseases in older patients affect circadian rhythms and sleep. Copyright © 2017 Elsevier Inc. All rights reserved.

[Interpersonal and social rhythm therapy (IPSRT)].

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Bottai, T; Biloa-Tang, M; Christophe, S; Dupuy, C; Jacquesy, L; Kochman, F; Meynard, J-A; Papeta, D; Rahioui, H; Adida, M; Fakra, E; Kaladjian, A; Pringuey, D; Azorin, J-M

2010-12-01

Bipolar disorder is common, recurrent, often severe and debiliting disorder. All types of bipolar disorder have a common determinant: depressive episode. It is justify to propose a psychotherapy which shown efficacy in depression. Howewer, perturbations in circadian rhythms have been implicated in the genesis of each episode of the illness. Biological circadian dysregulation can be encouraged by alteration of time-givers (Zeitgebers) or occurrence of time-disturbers (Zeitstörers). Addition of social rhythm therapy to interpersonal psychotherapy leads to create a new psychotherapy adaptated to bipolar disorders: InterPersonal and Social Rhythm Therapy (IPSRT). IPSRT, in combinaison with medication, has demonstrated efficacy as a treatment for bipolar disorders. IPSRT combines psychoeducation, behavioral strategy to regularize daily routines and interpersonal psychotherapy which help patients cope better with the multiple psychosocial and relationship problems associated with this chronic disorder. The main issues of this psychotherapy are: to take the history of the patient's illness and review of medication, to help patient for "grief for the lost healthy self" translated in the french version in "acceptance of a long-term medical condition", to give the sick role, to examinate the current relationships and changes proximal to the emergence of mood symptoms in the four problem areas (unresolved grief, interpersonal disputes, role transitions, role déficits), to examinate and increase daily routines and social rhythms. French version of IPSRT called TIPARS (with few differences), a time-limited psychotherapy, in 24 sessions during approximatively 6 months, is conducted in three phases. In the initial phase, the therapist takes a thorough history of previous episodes and their interpersonal context and a review of previous medication, provides psychoeducation, evaluates social rhythms, introduces the Social Rhythm Metric, identifies the patient's main interpersonal

RHYTHM DISTURBANCES DURING COLONOSCOPY

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D. Jordanov

2012-08-01

Full Text Available Purpose: The purpose of this study is to assess the risk of inducing rhythm disturbances of the heart during colonoscopy.Patients and methods used: 80 patients had undergone colonoscopyper formed by two experienced specialists of endoscopy for the period from March to December 2011. The endoscopies were performed without premedication and sedation. Holter was placed on each patient one hour before the endoscopic examination, and the record continued one hour after the manipulation. The blood pressure was measured before, during and after the procedure.Results: During colonoscopy 25 patients (31,25% manifested rhythm disorders. In 15 patients (18,75% sinus tachycardia occurred. In 7 patients (8,75% suptraventricular extra systoles were observed and in 3 patients (3,75% - ventricular extra systoles. No ST-T changes were found. Highest values of the blood pressure were measured before and during the endoscopy, but the values did not exceed 160/105 mmHg. In 10 patients (12,5% a hypotensive reaction was observed, bur the values were not lower than 80/ 50. In 2 patients there was a short bradycardia with a heart frequency 50-55 /min.Conclusions: Our results showed that the rhythm disorders during lower colonoscopy occur in approximately 1/3 of the examined patients, there is an increase or decrease of the blood pressure in some patients, but that doesn’t require physician’s aid and the examination can be carried out safely without monitoring.

Speech-like rhythm in a voiced and voiceless orangutan call.

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Adriano R Lameira

Full Text Available The evolutionary origins of speech remain obscure. Recently, it was proposed that speech derived from monkey facial signals which exhibit a speech-like rhythm of ∼5 open-close lip cycles per second. In monkeys, these signals may also be vocalized, offering a plausible evolutionary stepping stone towards speech. Three essential predictions remain, however, to be tested to assess this hypothesis' validity; (i Great apes, our closest relatives, should likewise produce 5Hz-rhythm signals, (ii speech-like rhythm should involve calls articulatorily similar to consonants and vowels given that speech rhythm is the direct product of stringing together these two basic elements, and (iii speech-like rhythm should be experience-based. Via cinematic analyses we demonstrate that an ex-entertainment orangutan produces two calls at a speech-like rhythm, coined "clicks" and "faux-speech." Like voiceless consonants, clicks required no vocal fold action, but did involve independent manoeuvring over lips and tongue. In parallel to vowels, faux-speech showed harmonic and formant modulations, implying vocal fold and supralaryngeal action. This rhythm was several times faster than orangutan chewing rates, as observed in monkeys and humans. Critically, this rhythm was seven-fold faster, and contextually distinct, than any other known rhythmic calls described to date in the largest database of the orangutan repertoire ever assembled. The first two predictions advanced by this study are validated and, based on parsimony and exclusion of potential alternative explanations, initial support is given to the third prediction. Irrespectively of the putative origins of these calls and underlying mechanisms, our findings demonstrate irrevocably that great apes are not respiratorily, articulatorilly, or neurologically constrained for the production of consonant- and vowel-like calls at speech rhythm. Orangutan clicks and faux-speech confirm the importance of rhythmic speech

Maternal and infant activity: Analytic approaches for the study of circadian rhythm.

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Thomas, Karen A; Burr, Robert L; Spieker, Susan

2015-11-01

The study of infant and mother circadian rhythm entails choice of instruments appropriate for use in the home environment as well as selection of analytic approach that characterizes circadian rhythm. While actigraphy monitoring suits the needs of home study, limited studies have examined mother and infant rhythm derived from actigraphy. Among this existing research a variety of analyses have been employed to characterize 24-h rhythm, reducing ability to evaluate and synthesize findings. Few studies have examined the correspondence of mother and infant circadian parameters for the most frequently cited approaches: cosinor, non-parametric circadian rhythm analysis (NPCRA), and autocorrelation function (ACF). The purpose of this research was to examine analytic approaches in the study of mother and infant circadian activity rhythm. Forty-three healthy mother and infant pairs were studied in the home environment over a 72h period at infant age 4, 8, and 12 weeks. Activity was recorded continuously using actigraphy monitors and mothers completed a diary. Parameters of circadian rhythm were generated from cosinor analysis, NPCRA, and ACF. The correlation among measures of rhythm center (cosinor mesor, NPCRA mid level), strength or fit of 24-h period (cosinor magnitude and R(2), NPCRA amplitude and relative amplitude (RA)), phase (cosinor acrophase, NPCRA M10 and L5 midpoint), and rhythm stability and variability (NPCRA interdaily stability (IS) and intradaily variability (IV), ACF) was assessed, and additionally the effect size (eta(2)) for change over time evaluated. Results suggest that cosinor analysis, NPCRA, and autocorrelation provide several comparable parameters of infant and maternal circadian rhythm center, fit, and phase. IS and IV were strongly correlated with the 24-h cycle fit. The circadian parameters analyzed offer separate insight into rhythm and differing effect size for the detection of change over time. Findings inform selection of analysis and

Biology and evolution of the endogenous koala retrovirus.

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Tarlinton, R; Meers, J; Young, P

2008-11-01

Although endogenous retroviruses are ubiquitous features of all mammalian genomes, the process of initial germ line invasion and subsequent inactivation from a pathogenic element has not yet been observed in a wild species. Koala retrovirus (KoRV) provides a unique opportunity to study this process of endogenisation in action as it still appears to be spreading through the koala population. Ongoing expression of the endogenous sequence and consequent high levels of viraemia have been linked to neoplasia and immunosuppression in koalas. This apparently recent invader of the koala genome shares a remarkably close sequence relationship with the pathogenic exogenous Gibbon ape leukaemia virus (GALV), and comparative analyses of KoRV and GALVare helping to shed light on how retroviruses in general adapt to a relatively benign or at least less pathogenic existence within a new host genome. (Part of a multi-author review).

Social Rhythm and Mental Health: A Cross-Cultural Comparison.

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Jürgen Margraf

Full Text Available Social rhythm refers to the regularity with which one engages in social activities throughout the week, and has established links with bipolar disorder, as well as some links with depression and anxiety. The aim of the present study is to examine social rhythm and its relationship to various aspects of health, including physical health, negative mental health, and positive mental health.Questionnaire data were obtained from a large-scale multi-national sample of 8095 representative participants from the U.S., Russia, and Germany.Results indicated that social rhythm irregularity is related to increased reporting of health problems, depression, anxiety, and stress. In contrast, greater regularity is related to better overall health state, life satisfaction, and positive mental health. The effects are generally small in size, but hold even when controlling for gender, marital status, education, income, country, and social support. Further, social rhythm means differ across Russia, the U.S., and Germany. Relationships with mental health are present in all three countries, but differ in magnitude.Social rhythm irregularity is related to mental health in Russia, the U.S., and Germany.

Are circadian rhythms new pathways to understand Autism Spectrum Disorder?

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Geoffray, M-M; Nicolas, A; Speranza, M; Georgieff, N

2016-11-01

Autism Spectrum Disorder (ASD) is a frequent neurodevelopmental disorder. ASD is probably the result of intricate interactions between genes and environment altering progressively the development of brain structures and functions. Circadian rhythms are a complex intrinsic timing system composed of almost as many clocks as there are body cells. They regulate a variety of physiological and behavioral processes such as the sleep-wake rhythm. ASD is often associated with sleep disorders and low levels of melatonin. This first point raises the hypothesis that circadian rhythms could have an implication in ASD etiology. Moreover, circadian rhythms are generated by auto-regulatory genetic feedback loops, driven by transcription factors CLOCK and BMAL1, who drive transcription daily patterns of a wide number of clock-controlled genes (CCGs) in different cellular contexts across tissues. Among these, are some CCGs coding for synapses molecules associated to ASD susceptibility. Furthermore, evidence emerges about circadian rhythms control of time brain development processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Speech rhythm in Kannada speaking adults who stutter.

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Maruthy, Santosh; Venugopal, Sahana; Parakh, Priyanka

2017-10-01

A longstanding hypothesis about the underlying mechanisms of stuttering suggests that speech disfluencies may be associated with problems in timing and temporal patterning of speech events. Fifteen adults who do and do not stutter read five sentences, and from these, the vocalic and consonantal durations were measured. Using these, pairwise variability index (raw PVI for consonantal intervals and normalised PVI for vocalic intervals) and interval based rhythm metrics (PercV, DeltaC, DeltaV, VarcoC and VarcoV) were calculated for all the participants. Findings suggested higher mean values in adults who stutter when compared to adults who do not stutter for all the rhythm metrics except for VarcoV. Further, statistically significant difference between the two groups was found for all the rhythm metrics except for VarcoV. Combining the present results with consistent prior findings based on rhythm deficits in children and adults who stutter, there appears to be strong empirical support for the hypothesis that individuals who stutter may have deficits in generation of rhythmic speech patterns.

Time-Dependent Trapping of Pollinators Driven by the Alignment of Floral Phenology with Insect Circadian Rhythms

Directory of Open Access Journals (Sweden)

Jenny Y. Y. Lau

2017-06-01

Full Text Available Several evolutionary lineages in the early divergent angiosperm family Annonaceae possess flowers with a distinctive pollinator trapping mechanism, in which floral phenological events are very precisely timed in relation with pollinator activity patterns. This contrasts with previously described angiosperm pollinator traps, which predominantly function as pitfall traps. We assess the circadian rhythms of pollinators independently of their interactions with flowers, and correlate these data with detailed assessments of floral phenology. We reveal a close temporal alignment between patterns of pollinator activity and the floral phenology driving the trapping mechanism (termed ‘circadian trapping’ here. Non-trapping species with anthesis of standard duration (c. 48 h cannot be pollinated effectively by pollinators with a morning-unimodal activity pattern; non-trapping species with abbreviated anthesis (23–27 h face limitations in utilizing pollinators with a bimodal circadian activity; whereas species that trap pollinators (all with short anthesis can utilize a broader range of potential pollinators, including those with both unimodal and bimodal circadian rhythms. In addition to broadening the range of potential pollinators based on their activity patterns, circadian trapping endows other selective advantages, including the possibility of an extended staminate phase to promote pollen deposition, and enhanced interfloral movement of pollinators. The relevance of the alignment of floral phenological changes with peaks in pollinator activity is furthermore evaluated for pitfall trap pollination systems.

[A complex of blood-sucking mosquitoes (Diptera, Culicidae) in the focus of West Nile fever in the Volgograd Region. III. Species feeding on birds and man and the rhythms of their nocturnal activity].

Science.gov (United States)

Lopatina, Iu V; Bezzhonova, O V; Fedorova, M V; Bulgakova, T V; Platonov, A E

2007-01-01

The rate and nocturnal rhythm of mosquito attacks of birds and human beings were studied in the open biotopes of Volgograd and its vicinity in 2004. Thirteen and 11 species of the subfamily Culicinae were collected under the Berezantsev bell and from the traps containing a chicken (a hen), respectively; of them 9 species were common. The mosquitoes of an Anopheles maculipennis complex were caught in a small portion to the traps of both types. Most species of Aedes were highly anthropophilic, showed the minimum activity at night and their abundance considerably decreased by the early transmission period. Among the species that were active during the transmission period, Ae. vexans, Coq. richiardii, and Cx. modestus more intensively attacked a human being than birds and Cx. pipiens was frequently attracted into the hen traps. The attraction of each species of the caught varied during the transmission period. The maximum attacks of Cx. modestus and Cx. pipiens on man and birds coincide and those of Coq. Richiardii and Cx. pipiens on man was observed earlier than on birds. A possible role of mosquitoes of different species in the epizootic and epidemiological processes is discussed.

Rhythm Perception and Its Role in Perception and Learning of Dysrhythmic Speech.

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Borrie, Stephanie A; Lansford, Kaitlin L; Barrett, Tyson S

2017-03-01

The perception of rhythm cues plays an important role in recognizing spoken language, especially in adverse listening conditions. Indeed, this has been shown to hold true even when the rhythm cues themselves are dysrhythmic. This study investigates whether expertise in rhythm perception provides a processing advantage for perception (initial intelligibility) and learning (intelligibility improvement) of naturally dysrhythmic speech, dysarthria. Fifty young adults with typical hearing participated in 3 key tests, including a rhythm perception test, a receptive vocabulary test, and a speech perception and learning test, with standard pretest, familiarization, and posttest phases. Initial intelligibility scores were calculated as the proportion of correct pretest words, while intelligibility improvement scores were calculated by subtracting this proportion from the proportion of correct posttest words. Rhythm perception scores predicted intelligibility improvement scores but not initial intelligibility. On the other hand, receptive vocabulary scores predicted initial intelligibility scores but not intelligibility improvement. Expertise in rhythm perception appears to provide an advantage for processing dysrhythmic speech, but a familiarization experience is required for the advantage to be realized. Findings are discussed in relation to the role of rhythm in speech processing and shed light on processing models that consider the consequence of rhythm abnormalities in dysarthria.

Circadian rhythm disturbance after radiotherapy for brain tumor in infantile period

International Nuclear Information System (INIS)

Kubota, Masaya; Shinozaki, Masako; Sasaki, Hideo.

1993-01-01

We report a 19-year-old man suffering from circadian sleep-wake (S-W) rhythm disturbance after total tumor resection and whole brain irradiation. The patient was diagnosed as having astrocytoma in the right temporal lobe by CT scan and angiography at the age of 6 months. After total tumor resection and whole brain irradiation ( 60 Co 60 Gy), he showed profound psychomotor retardation, endoclinologic dysfunction including hypothyroidism and growth hormone deficiency, and S-W rhythm disturbance. At the age of 19, brain MRI revealed asymmetrical low intensity in the hypothalamic region. On endoclinological examination panhypopituitarism due to primary hypothalamic lesion was evident. His S-W rhythm was disturbed; i.e., sleep periods were dispersedly distributed throughout 24 hours. So he showed a lethargic tendency in the daytime. All-day polysomnography revealed abnormal sleep structure such as the absence of sleep spindle and hump, peripheral apnea, snoring and low oxygen saturation. After L-thyroxine supplementation his daily activity improved gradually. The decrease in short time sleep and tendency of a free-running rhythm were observed and oxygen saturation improved remarkably. Peripheral apnea and snoring disappeared. This wakening effect of L-thyroxine administration may be due to improvement of hypothyroidism symptom such as myxoedematous pharynx. It also seems related to the alteration of the central S-W rhythm regulation, because free-running rhythm appeared after L-thyroxine administration. Vitamin B 12 (VB 12 ), which has been reported to be effective for S-W rhythm disorders, was not effective for our patient's free-running rhythm. Compared with the patients responding to VB 12 , our patient's organic brain damage was more evident radiologically and endoclinologically. Following the hypothesis that VB 12 has a potential to reinforce the entrainment of circadian rhythm, our patient's organic brain damage may include entrainment system. (author)

Musical rhythm spectra from Bach to Joplin obey a 1/f power law.

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Levitin, Daniel J; Chordia, Parag; Menon, Vinod

2012-03-06

Much of our enjoyment of music comes from its balance of predictability and surprise. Musical pitch fluctuations follow a 1/f power law that precisely achieves this balance. Musical rhythms, especially those of Western classical music, are considered highly regular and predictable, and this predictability has been hypothesized to underlie rhythm's contribution to our enjoyment of music. Are musical rhythms indeed entirely predictable and how do they vary with genre and composer? To answer this question, we analyzed the rhythm spectra of 1,788 movements from 558 compositions of Western classical music. We found that an overwhelming majority of rhythms obeyed a 1/f(β) power law across 16 subgenres and 40 composers, with β ranging from ∼0.5-1. Notably, classical composers, whose compositions are known to exhibit nearly identical 1/f pitch spectra, demonstrated distinctive 1/f rhythm spectra: Beethoven's rhythms were among the most predictable, and Mozart's among the least. Our finding of the ubiquity of 1/f rhythm spectra in compositions spanning nearly four centuries demonstrates that, as with musical pitch, musical rhythms also exhibit a balance of predictability and surprise that could contribute in a fundamental way to our aesthetic experience of music. Although music compositions are intended to be performed, the fact that the notated rhythms follow a 1/f spectrum indicates that such structure is no mere artifact of performance or perception, but rather, exists within the written composition before the music is performed. Furthermore, composers systematically manipulate (consciously or otherwise) the predictability in 1/f rhythms to give their compositions unique identities.

[Psychoeducation and interpersonal and social rhythm therapy for bipolar disorder].

Science.gov (United States)

Mizushima, Hiroko

2011-01-01

In treating bipolar disorder, specific psychotherapies in adjunct to pharmacotherapy have been shown to be effective in preventing new episodes and treating depressive episodes. Among those, interpersonal and social rhythm therapy (IPSRT) developed by Frank, amalgamation of interpersonal psychotherapy (IPT) with behavioral therapy focused on social rhythm has been shown to be an efficacious adjunct to mediation in preventing new episodes in bipolar I patients and in treating depression in bipolar I arid II disorder. IPSRT has also been shown to enhance total functioning, relationship functioning and life satisfaction among patients with bipolar disorder, even after pretreatment functioning and concurrent depression were covaried. IPSRT was designed to directly address the major pathways to recurrence in bipolar disorder, namely medication nonadherence, stressful life events, and disruptions in social rhythms. IPT, originated by Klerman et al., is a strategic time-limited psychotherapy focused on one or two of four current interpersonal problem areas (ie, grief, interpersonal role disputes, role transitions, and interpersonal dificits). In IPSRT, the fifth problem area "grief for the lost healthy self" has been added in order to promote acceptance of the diagnosis and the need for life-long treatment. Social rhythm therapy is a behavioral approach aiming at increasing regularity of social rhythms using the Social Rhythm Metric (SRM), a chart to record daily social activities including how stimulating they were, developed from observation that disruptions in social rhythms often trigger affective episodes in patients with bipolar disorder. IPSRT also appears to be a promising intervention for a subset of individuals with bipolar II depression as monotherapy for the acute treatment.

Light Rhythms in Architecture

DEFF Research Database (Denmark)

Bülow, Katja

2013-01-01

formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...

The Endogenous Exposome

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Nakamura, Jun; Mutlu, Esra; Sharma, Vyom; Collins, Leonard; Bodnar, Wanda; Yu, Rui; Lai, Yongquan; Moeller, Benjamin; Lu, Kun; Swenberg, James

2014-01-01

The concept of the Exposome, is a compilation of diseases and one’s lifetime exposure to chemicals, whether the exposure comes from environmental, dietary, or occupational exposures; or endogenous chemicals that are formed from normal metabolism, inflammation, oxidative stress, lipid peroxidation, infections, and other natural metabolic processes such as alteration of the gut microbiome. In this review, we have focused on the Endogenous Exposome, the DNA damage that arises from the production of endogenous electrophilic molecules in our cells. It provides quantitative data on endogenous DNA damage and its relationship to mutagenesis, with emphasis on when exogenous chemical exposures that produce identical DNA adducts to those arising from normal metabolism cause significant increases in total identical DNA adducts. We have utilized stable isotope labeled chemical exposures of animals and cells, so that accurate relationships between endogenous and exogenous exposures can be determined. Advances in mass spectrometry have vastly increased both the sensitivity and accuracy of such studies. Furthermore, we have clear evidence of which sources of exposure drive low dose biology that results in mutations and disease. These data provide much needed information to impact quantitative risk assessments, in the hope of moving towards the use of science, rather than default assumptions. PMID:24767943

A Circadian Rhythm Regulating Hyphal Melanization in Cercospora Kikuchii

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Circadian rhythms, biochemical or developmental processes with a period length of approximately 24 hours, are thoroughly documented in plants and animals. However, virtually all of what is currently known about circadian rhythms in fungi is derived from the model fungus, Neurospora crassa, including...

Calculating activation energies for temperature compensation in circadian rhythms

International Nuclear Information System (INIS)

Bodenstein, C; Heiland, I; Schuster, S

2011-01-01

Many biological species possess a circadian clock, which helps them anticipate daily variations in the environment. In the absence of external stimuli, the rhythm persists autonomously with a period of approximately 24 h. However, single pulses of light, nutrients, chemicals or temperature can shift the clock phase. In the case of light- and temperature-cycles, this allows entrainment of the clock to cycles of exactly 24 h. Circadian clocks have the remarkable property of temperature compensation, that is, the period of the circadian rhythm remains relatively constant within a physiological range of temperatures. For several organisms, temperature-regulated processes within the circadian clock have been identified in recent years. However, how these processes contribute to temperature compensation is not fully understood. Here, we theoretically investigate temperature compensation in general oscillatory systems. It is known that every oscillator can be locally temperature compensated around a reference temperature, if reactions are appropriately balanced. A balancing is always possible if the control coefficient with respect to the oscillation period of at least one reaction in the oscillator network is positive. However, for global temperature compensation, the whole physiological temperature range is relevant. Here, we use an approach which leads to an optimization problem subject to the local balancing principle. We use this approach to analyse different circadian clock models proposed in the literature and calculate activation energies that lead to temperature compensation

Production of endogenous pyrogen.

Science.gov (United States)

Dinarello, C A

1979-01-01

The production and release of endogenous pyrogen by the host is the first step in the pathogenesis of fever. Endogenous pyrogen is a low-molecular-weight protein released from phagocytic leukocytes in response to several substances of diverse nature. Some of these agents stimulate production of endogenous pyrogen because they are toxic; others act as antigens and interact with either antibody or sensitized lymphocytes in order to induce its production. Some tumors of macrophage origin produce the molecule spontaneously. Whatever the mechanism involved, endogenous pyrogen is synthesized following transcription of new DNA and translation of mRNA into new protein. Once synthesis is completed, the molecule is released without significant intracellular storage. Recent evidence suggests that following release, molecular aggregates form which are biologically active. In its monomer form, endogenous pyrogen is a potent fever-producing substance and mediates fever by its action on the thermoregulatory center.

Familial circadian rhythm disorder in the diurnal primate, Macaca mulatta.

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Irina V Zhdanova

Full Text Available In view of the inverse temporal relationship of central clock activity to physiological or behavioral outputs in diurnal and nocturnal species, understanding the mechanisms and physiological consequences of circadian disorders in humans would benefit from studies in a diurnal animal model, phylogenetically close to humans. Here we report the discovery of the first intrinsic circadian disorder in a family of diurnal non-human primates, the rhesus monkey. The disorder is characterized by a combination of delayed sleep phase, relative to light-dark cycle, mutual desynchrony of intrinsic rhythms of activity, food intake and cognitive performance, enhanced nighttime feeding or, in the extreme case, intrinsic asynchrony. The phenotype is associated with normal length of intrinsic circadian period and requires an intact central clock, as demonstrated by an SCN lesion. Entrainment to different photoperiods or melatonin administration does not eliminate internal desynchrony, though melatonin can temporarily reinstate intrinsic activity rhythms in the animal with intrinsic asynchrony. Entrainment to restricted feeding is highly effective in animals with intrinsic or SCN lesion-induced asynchrony. The large isolated family of rhesus macaques harboring the disorder provides a powerful new tool for translational research of regulatory circuits underlying circadian disorders and their effective treatment.

Daily rhythm of phosphoenolpyruvate carboxylase in Crassulacean acid metabolism plants : Immunological evidence for the absence of a rhythm in protein synthesis.

Science.gov (United States)

Brulfert, J; Vidal, J; Gadal, P; Queiroz, O

1982-11-01

Immunotitration of phosphoenolpyruvate carboxylase (EC 4.1.1.31) extracted from leaves of Kalanchoe blossfeldiana v. Poelln. cv. Tom Thumb. It was established that at different times of the day-night cycle the daily rhythm of enzyme capacity does not result from a rhythm in protein synthesis, but rather from changes in the specific activity of the enzyme.

Autism as a disorder of biological and behavioral rhythms: Towards new therapeutic perspectives

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Sylvie eTordjman

2015-02-01

Full Text Available There is a growing interest in the role of biological and behavioral rhythms in typical and atypical development. Recent studies in cognitive and developmental psychology have highlighted the importance of rhythmicity and synchrony of motor, emotional and relational rhythms in early development of social communication. The synchronization of rhythms allows tuning and adaptation to the external environment. The role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of peripheral oscillators suggests that this hormone might be also involved in the synchrony of motor, emotional and relational rhythms. Autism provides a challenging model of physiological and behavioral rhythm disturbances and their possible effects on the development of social communication impairments and repetitive behaviors or interests. This article situates autism as a disorder of biological and behavioral rhythms and reviews the recent literature on the role of rhythmicity and synchrony of rhythms in child development. Finally, the hypothesis is developed that an integrated approach focusing on biological, motor, emotional and relational rhythms may open interesting therapeutic perspectives for children with autism. More specifically, promising avenues are discussed for potential therapeutic benefits in autism spectrum disorder of melatonin combined with developmental behavioral interventions that emphasize synchrony such as the Early Start Denver Model (ESDM.

Autism as a disorder of biological and behavioral rhythms: toward new therapeutic perspectives.

Science.gov (United States)

Tordjman, Sylvie; Davlantis, Katherine S; Georgieff, Nicolas; Geoffray, Marie-Maude; Speranza, Mario; Anderson, George M; Xavier, Jean; Botbol, Michel; Oriol, Cécile; Bellissant, Eric; Vernay-Leconte, Julie; Fougerou, Claire; Hespel, Anne; Tavenard, Aude; Cohen, David; Kermarrec, Solenn; Coulon, Nathalie; Bonnot, Olivier; Dawson, Geraldine

2015-01-01

There is a growing interest in the role of biological and behavioral rhythms in typical and atypical development. Recent studies in cognitive and developmental psychology have highlighted the importance of rhythmicity and synchrony of motor, emotional, and interpersonal rhythms in early development of social communication. The synchronization of rhythms allows tuning and adaptation to the external environment. The role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of the circadian clocks network suggests that this hormone might be also involved in the synchrony of motor, emotional, and interpersonal rhythms. Autism provides a challenging model of physiological and behavioral rhythm disturbances and their possible effects on the development of social communication impairments and repetitive behaviors and interests. This article situates autism as a disorder of biological and behavioral rhythms and reviews the recent literature on the role of rhythmicity and synchrony of rhythms in child development. Finally, the hypothesis is developed that an integrated approach focusing on biological, motor, emotional, and interpersonal rhythms may open interesting therapeutic perspectives for children with autism. More specifically, promising avenues are discussed for potential therapeutic benefits in autism spectrum disorder of melatonin combined with developmental behavioral interventions that emphasize synchrony, such as the Early Start Denver Model.

Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

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Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

2015-01-01

Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum) and auditory rhythms (e.g., hearing music while walking). Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse), suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

Internal Medicine Physicians’ Perceptions Regarding Rate versus Rhythm Control for Atrial Fibrillation

Science.gov (United States)

McCabe, James M.; Johnson, Colleen J; Marcus, Gregory M

2011-01-01

Atrial fibrillation (AF) is often managed by general internal medicine physicians. Available data suggest that guidelines regarding AF management are often not followed, but the reasons for this remain unknown. We sought to assess the knowledge and beliefs of internists regarding strategies to treat AF. We conducted a national electronic survey of internal medicine physicians regarding their perceptions of optimal AF management, with an emphasis on the rationale for choosing a rhythm or rate control strategy. One hundred and forty-eight physicians from 36 different states responded (representing at least 19% of unique e-mails opened). Half of the respondents reported managing their AF patients independently without referral to a cardiologist. Seventy-three percent of participants believe a rhythm control strategy conveys a decreased stroke risk, 64% believe there is a mortality benefit to rhythm control, and 55% think that it would help avoid long term anticoagulation. Comparing those who prefer a rhythm control strategy to everyone else, those who favor rhythm control statistically significantly more often believe that rhythm control reduces the risk for stroke (96% versus 67%, p=0.009) and that rhythm control allows for the discontinuation of anticoagulation therapy (76% versus 49%, p=0.045). In conclusion, contrary to available data in clinical trials and recent guidelines regarding the rationale for choosing a rhythm control strategy in treating AF, the majority of study participants believe that rhythm control decreases stroke risk, decreases mortality, and allows for discontinuation of anticoagulation therapy. These prevalent misconceptions may substantially contribute to guideline non-adherence. PMID:19195516

Endogenous Locus Reporter Assays.

Science.gov (United States)

Liu, Yaping; Hermes, Jeffrey; Li, Jing; Tudor, Matthew

2018-01-01

Reporter gene assays are widely used in high-throughput screening (HTS) to identify compounds that modulate gene expression. Traditionally a reporter gene assay is built by cloning an endogenous promoter sequence or synthetic response elements in the regulatory region of a reporter gene to monitor transcriptional activity of a specific biological process (exogenous reporter assay). In contrast, an endogenous locus reporter has a reporter gene inserted in the endogenous gene locus that allows the reporter gene to be expressed under the control of the same regulatory elements as the endogenous gene, thus more accurately reflecting the changes seen in the regulation of the actual gene. In this chapter, we introduce some of the considerations behind building a reporter gene assay for high-throughput compound screening and describe the methods we have utilized to establish 1536-well format endogenous locus reporter and exogenous reporter assays for the screening of compounds that modulate Myc pathway activity.

Northern Elephant Seals Memorize the Rhythm and Timbre of Their Rivals' Voices.

Science.gov (United States)

Mathevon, Nicolas; Casey, Caroline; Reichmuth, Colleen; Charrier, Isabelle

2017-08-07

The evolutionary origin of rhythm perception, a cognitive ability essential to musicality, remains unresolved [1-5]. The ability to perceive and memorize rhythmic sounds is widely shared among humans [6] but seems rare among other mammals [7, 8]. Although the perception of temporal metrical patterns has been found in a few species, this ability has only been demonstrated through behavioral training [9] (but see [10] for an example of spontaneous tempo coordination in a bonobo), and there is no experimental evidence to indicate its biological function. Furthermore, there is no example of a non-human mammal able to remember and recognize auditory rhythmic patterns among a wide range of tempi. In the northern elephant seal Mirounga angustirostris, the calls of mature males comprise a rhythmic series of pulses, with the call of each individual characterized by its tempo and timbre; these individual vocal signatures are stable over years and across contexts [11]. Here, we report that northern elephant seal males routinely memorize and recognize the unique tempo and timbre of their rivals' voices and use this rhythmic information to individually identify competitors, which facilitates navigation within the social network of the rookery. By performing playbacks with natural and modified vocalizations, we show that males are sensitive to call rhythm disruption independently of modification of spectral features and that they use both temporal and spectral cues to identify familiar rivals. While spectral features of calls typically encode individual identity in mammalian vocalizations [12], this is the first example of this phenomenon involving sound rhythm. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relation between functional connectivity and rhythm discrimination in children who do and do not stutter

Directory of Open Access Journals (Sweden)

Soo-Eun Chang

2016-01-01

Full Text Available Our ability to perceive and produce rhythmic patterns in the environment supports fundamental human capacities ranging from music and language processing to the coordination of action. This article considers whether spontaneous correlated brain activity within a basal ganglia-thalamocortical (rhythm network is associated with individual differences in auditory rhythm discrimination. Moreover, do children who stutter with demonstrated deficits in rhythm perception have weaker links between rhythm network functional connectivity and rhythm discrimination? All children in the study underwent a resting-state fMRI session, from which functional connectivity measures within the rhythm network were extracted from spontaneous brain activity. In a separate session, the same children completed an auditory rhythm-discrimination task, where behavioral performance was assessed using signal detection analysis. We hypothesized that in typically developing children, rhythm network functional connectivity would be associated with behavioral performance on the rhythm discrimination task, but that this relationship would be attenuated in children who stutter. Results supported our hypotheses, lending strong support for the view that (1 children who stutter have weaker rhythm network connectivity and (2 the lack of a relation between rhythm network connectivity and rhythm discrimination in children who stutter may be an important contributing factor to the etiology of stuttering.

Right- and left-brain hemisphere. Rhythm in reaction time to light signals is task-load-dependent: age, gender, and handgrip strength rhythm comparisons.

Science.gov (United States)

Reinberg, Alain; Bicakova-Rocher, Alena; Mechkouri, Mohamed; Ashkenazi, Israel

2002-11-01

In healthy mature subjects simple reaction time (SRT) to a single light signal (an easy task) is associated with a prominent rhythm with tau = 24 h of dominant (DH) as well as nondominant (NDH) hand performance, while three-choice reaction time (CRT), a complex task, is associated with tau = 24 h of the DH but tau gender on the difference in tau of the NDH and DH, as it relates to the corresponding cortical hemisphere of the brain, in comparison to the rhythm in handgrip strength. Healthy subjects, 9 (5 M and 4 F) adolescents 10-16 yr of age and 15 (8 M and 7 F) adults 18-67 yr of age, active between 08:00 +/- 1 h and 23:00 +/- 1:30 h and free of alcohol, tobacco, and drug consumption volunteered. Data were gathered longitudinally at home and work 4-7 times daily for 11-20 d. At each test time the following variables were assessed: grip strength of both hands (Dynamometer: Colin-Gentile, Paris, France); single reaction time to a yellow signal (SRT); and CRT to randomized yellow, red, or green signal series with varying instruction from test to test (Psycholog-24: Biophyderm, France). Rhythms in the performance in SRT, CRT, and handgrip strength of both DH and NDH were explored. The sleep-wake rhythm was assessed by sleep-logs, and in a subset of 14 subjects it was also assessed by wrist actigraphy (Mini-Motionlogger: AMI, Ardsley NY). Exploration of the prominent period tau of time series was achieved by a special power spectra analysis for unequally spaced data. Cosinor analysis was used to quantify the rhythm amplitude A and rhythm-adjusted mean M of the power spectral analysis determined trial tau. A 24h sleep-wake rhythm was detected in almost all cases. In adults, a prominent tau of 24 h characterized the performance of the easy task by both the DH and NDH. In adults a prominent tau of 24 h was also detected in the complex CRT task performed by the DH, but for the NDH the tau was gender-related but was age-related since it was seldom observed in adolescent

Mood Disorders, Circadian Rhythms, Melatonin and Melatonin Agonists

Directory of Open Access Journals (Sweden)

M.A. Quera Salva

2012-04-01

Full Text Available Recent advances in the understanding of circadian rhythms have led to an interest in the treatment of major depressive disorder with chronobiotic agents. Many tissues have autonomous circadian rhythms, which are orchestrated by the master clock, situated in the suprachiasmatic nucleus (SNC. Melatonin (N-acetyl-5-hydroxytryptamine is secreted from the pineal gland during darkness. Melatonin acts mainly on MT1 and MT2 receptors, which are present in the SNC, regulating physiological and neuroendocrine functions, including circadian entrainment, referred to as the chronobiotic effet. Circadian rhythms has been shown to be either misaligned or phase shifted or decreased in amplitude in both acute episodes and relapse of major depressive disorder (MDD and bipolar disorder. Manipulation of circadian rhythms either using physical treatments (such as high intensity light or behavioral therapy has shown promise in improving symptoms. Pharmacotherapy using melatonin and pure melatonin receptor agonists, while improving sleep, has not been shown to improve symptoms of depression. A novel antidepressant, agomelatine, combines 5HT2c antagonist and melatonin agonist action, and has shown promise in both acute treatment of MDD and in preventing relapse.

Circadian rhythms on skin function of hairless rats: light and thermic influences.

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Flo, Ana; Díez-Noguera, Antoni; Calpena, Ana C; Cambras, Trinitat

2014-03-01

Circadian rhythms are present in most functions of living beings. We have demonstrated the presence of circadian rhythms in skin variables (transepidermal water loss, TEWL; stratum corneum hydration, SCH; and skin temperature) in hairless rats under different environmental conditions of light and temperature. Circadian rhythms in TEWL and SCH showed mean amplitudes of about 20% and 14% around the mean, respectively, and appeared under light-dark cycles as well as under constant darkness. Environmental temperature was able to override TEWL, but not SCH rhythm, evidencing the dependency of TEWL on the temperature. Mean daily values of TEWL and SCH, and also the amplitude of TEWL rhythm, increased with the age of the animal. Under constant light, situation that induces arrhythmicity in rats, SCH and TEWL were inversely correlated. The results suggest the importance to take into account the functional skin rhythms in research in dermatological sciences. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Circadian rhythm of urinary potassium excretion during treatment with an angiotensin receptor blocker.

Science.gov (United States)

Ogiyama, Yoshiaki; Miura, Toshiyuki; Watanabe, Shuichi; Fuwa, Daisuke; Tomonari, Tatsuya; Ota, Keisuke; Kato, Yoko; Ichikawa, Tadashi; Shirasawa, Yuichi; Ito, Akinori; Yoshida, Atsuhiro; Fukuda, Michio; Kimura, Genjiro

2014-12-01

We have reported that the circadian rhythm of urinary potassium excretion (U(K)V) is determined by the rhythm of urinary sodium excretion (U(Na)V) in patients with chronic kidney disease (CKD). We also reported that treatment with an angiotensin receptor blocker (ARB) increased the U(Na)V during the daytime, and restored the non-dipper blood pressure (BP) rhythm into a dipper pattern. However, the circadian rhythm of U(K)V during ARB treatment has not been reported. Circadian rhythms of U(Na)V and U(K)V were examined in 44 patients with CKD undergoing treatment with ARB. Whole-day U(Na)V was not altered by ARB whereas whole-day U(K)V decreased. Even during the ARB treatment, the significant relationship persisted between the night/day ratios of U(Na)V and U(K)V (r=0.56, pcircadian rhythm of U(K)V was determined by the rhythm of UNaV even during ARB treatment. Changes in the circadian U(K)V rhythm were not determined by aldosterone but by U(Na)V. © The Author(s) 2013.

Ultradian activity rhythms in large groups of newly hatched chicks (Gallus gallus domesticus).

Science.gov (United States)

Nielsen, B L; Erhard, H W; Friggens, N C; McLeod, J E

2008-07-01

A clutch of young chicks housed with a mother hen exhibit ultradian (within day) rhythms of activity corresponding to the brooding cycle of the hen. In the present study clear evidence was found of ultradian activity rhythms in newly hatched domestic chicks housed in groups larger than natural clutch size without a mother hen or any other obvious external time-keeper. No consistent synchrony was found between groups housed in different pens within the same room. The ultradian rhythms disappeared with time and little evidence of group rhythmicity remained by the third night. This disappearance over time suggests that the presence of a mother hen may be pivotal for the long-term maintenance of these rhythms. The ultradian rhythm of the chicks may also play an important role in the initiation of brooding cycles during the behavioural transition of the mother hen from incubation to brooding. Computer simulations of individual activity rhythms were found to reproduce the observations made on a group basis. This was achievable even when individual chick rhythms were modelled as independent of each other, thus no assumptions of social facilitation are necessary to obtain ultradian activity rhythms on a group level.

Identification of a chicken (Gallus gallus) endogenous reference gene (Actb) and its application in meat adulteration.

Science.gov (United States)

Xiang, Wenjin; Shang, Ying; Wang, Qin; Xu, Yuancong; Zhu, Pengyu; Huang, Kunlun; Xu, Wentao

2017-11-01

The genes commonly used to determine meat species are mainly mitochondrial, but the copy numbers of such genes are high, meaning they cannot be accurately quantified. In this paper, for the first time, the chromosomal gene Actb was selected as an endogenous reference gene for chicken species. It was assayed in four different chicken varieties and 16 other species using both qualitative and quantitative PCR. No amplification of the Actb gene was found in species other than chicken and no allelic variations were detected in chicken. Southern blot and digital-PCR confirmed the Actb gene was present as a single copy in the chicken genome. The quantitative detection limit was 10pg of DNA, which is equivalent to eight copies. All experiments indicated that the Actb gene is a useful endogenous reference gene for chicken, and provides a convenient and accurate approach for detection of chicken in feed and food. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans

Science.gov (United States)

Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

2015-01-01

Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum) and auditory rhythms (e.g., hearing music while walking). Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse), suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement. PMID:26132703

Distractor Effect of Auditory Rhythms on Self-Paced Tapping in Chimpanzees and Humans.

Directory of Open Access Journals (Sweden)

Yuko Hattori

Full Text Available Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum and auditory rhythms (e.g., hearing music while walking. Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse, suggesting a tight link between the auditory and motor systems in the human brain. However, the evolutionary origin of spontaneous responses to auditory rhythms is unclear. Here, we report that chimpanzees and humans show a similar distractor effect in perceiving isochronous rhythms during rhythmic movement. We used isochronous auditory rhythms as distractor stimuli during self-paced alternate tapping of two keys of an electronic keyboard by humans and chimpanzees. When the tempo was similar to their spontaneous motor tempo, tapping onset was influenced by intermittent entrainment to auditory rhythms. Although this effect itself is not an advanced rhythmic ability such as dancing or singing, our results suggest that, to some extent, the biological foundation for spontaneous responses to auditory rhythms was already deeply rooted in the common ancestor of chimpanzees and humans, 6 million years ago. This also suggests the possibility of a common attentional mechanism, as proposed by the dynamic attending theory, underlying the effect of perceiving external rhythms on motor movement.

Effects of Some Aspects of Rhythm on Tempo Perception.

Science.gov (United States)

Wang, Cecilia Chu

1984-01-01

Results indicated that significantly more time is needed to perceive tempo increase than tempo decrease, uneven rhythm then even rhythm, and melody alone than melody with accompaniment. Furthermore, significant interaction effects involving beat locations of tempo change suggest that differential groupings may be a factor in tempo discrimination.…

Effects of tempo and timing of simple musical rhythms

NARCIS (Netherlands)

Repp, B.H.; Windsor, W.L.; Desain, P.W.M.

2002-01-01

In this study we investigated whether and how the timing of musical rhythms changes with tempo. Twelve skilled pianists played a monophonic 8-bar melody in 21 different rhythmic versions at 4 different tempi. Within bars, the rhythms represented all possible ordered pairs and triplets of note values

Rhythm generation through period concatenation in rat somatosensory cortex.

Directory of Open Access Journals (Sweden)

Mark A Kramer

2008-09-01

Full Text Available Rhythmic voltage oscillations resulting from the summed activity of neuronal populations occur in many nervous systems. Contemporary observations suggest that coexistent oscillations interact and, in time, may switch in dominance. We recently reported an example of these interactions recorded from in vitro preparations of rat somatosensory cortex. We found that following an initial interval of coexistent gamma ( approximately 25 ms period and beta2 ( approximately 40 ms period rhythms in the superficial and deep cortical layers, respectively, a transition to a synchronous beta1 ( approximately 65 ms period rhythm in all cortical layers occurred. We proposed that the switch to beta1 activity resulted from the novel mechanism of period concatenation of the faster rhythms: gamma period (25 ms+beta2 period (40 ms = beta1 period (65 ms. In this article, we investigate in greater detail the fundamental mechanisms of the beta1 rhythm. To do so we describe additional in vitro experiments that constrain a biologically realistic, yet simplified, computational model of the activity. We use the model to suggest that the dynamic building blocks (or motifs of the gamma and beta2 rhythms combine to produce a beta1 oscillation that exhibits cross-frequency interactions. Through the combined approach of in vitro experiments and mathematical modeling we isolate the specific components that promote or destroy each rhythm. We propose that mechanisms vital to establishing the beta1 oscillation include strengthened connections between a population of deep layer intrinsically bursting cells and a transition from antidromic to orthodromic spike generation in these cells. We conclude that neural activity in the superficial and deep cortical layers may temporally combine to generate a slower oscillation.

Sleep, 24-hour activity rhythms, and brain structure : A population-based study

NARCIS (Netherlands)

L.A. Zuurbier (Lisette)

2016-01-01

markdownabstractIn this thesis, Chapter 2 focuses on sleep, 24-hour activity rhythms and health. Chapter 2.1 describes the influence of demographics, lifestyle and sleep on 24-hour activity rhythms. In Chapter 2.2 sleep and 24-hour activity rhythms are used to predict mortality. This chapter is

Rhythm Perception and Its Role in Perception and Learning of Dysrhythmic Speech

Science.gov (United States)

Borrie, Stephanie A.; Lansford, Kaitlin L.; Barrett, Tyson S.

2017-01-01

Purpose: The perception of rhythm cues plays an important role in recognizing spoken language, especially in adverse listening conditions. Indeed, this has been shown to hold true even when the rhythm cues themselves are dysrhythmic. This study investigates whether expertise in rhythm perception provides a processing advantage for perception…

Impact of chronodisruption during primate pregnancy on the maternal and newborn temperature rhythms.

Directory of Open Access Journals (Sweden)

María Serón-Ferré

Full Text Available Disruption of the maternal environment during pregnancy is a key contributor to offspring diseases that develop in adult life. To explore the impact of chronodisruption during pregnancy in primates, we exposed pregnant capuchin monkeys to constant light (eliminating the maternal melatonin rhythm from the last third of gestation to term. Maternal temperature and activity circadian rhythms were assessed as well as the newborn temperature rhythm. Additionally we studied the effect of daily maternal melatonin replacement during pregnancy on these rhythms. Ten pregnant capuchin monkeys were exposed to constant light from 60% of gestation to term. Five received a daily oral dose of melatonin (250 µg kg/body weight at 1800 h (LL+Mel and the other five a placebo (LL. Six additional pregnant females were maintained in a 14∶10 light:dark cycles and their newborns were used as controls (LD. Rhythms were recorded 96 h before delivery in the mother and at 4-6 days of age in the newborn. Exposure to constant light had no effect on the maternal body temperature rhythm however it delayed the acrophase of the activity rhythm. Neither rhythm was affected by melatonin replacement. In contrast, maternal exposure to constant light affected the newborn body temperature rhythm. This rhythm was entrained in control newborns whereas LL newborns showed a random distribution of the acrophases over 24-h. In addition, mean temperature was decreased (34.0±0.6 vs 36.1±0.2°C, in LL and control, respectively P<0.05. Maternal melatonin replacement during pregnancy re-synchronized the acrophases and restored mean temperature to the values in control newborns. Our findings demonstrate that prenatal melatonin is a Zeitgeber for the newborn temperature rhythm and supports normal body temperature maintenance. Altogether these prenatal melatonin effects highlight the physiological importance of the maternal melatonin rhythm during pregnancy for the newborn primate.

Using Rhythms of Relationships to Understand Email Archives

National Research Council Canada - National Science Library

Perer, Adam; Shneiderman, Ben; Oard, Douglas W

2005-01-01

...: analyzing the temporal rhythms of social relationships. We provide methods for constructing meaningful rhythms from the email headers by identifying relationships and interpreting their attributes. With these visualization techniques, email archive explorers can uncover insights that may have been otherwise hidden in the archive. We apply our methods to an individual's fifteen-year email archive, which consists of about 45,000 messages and over 4,000 relationships.

Vegetative rhythm of some woody species

International Nuclear Information System (INIS)

Gagnaire, J.

1965-01-01

In laboratory conditions from march 1963 to april 1964, variations of calcium absorption by roots and translocation speed towards aerial parts of young norway spruce (Picea excelsa) in hydroponic growing, present fixed stages in a vegetative cycle: 1. from early april until end may a rapid rising of minerals from roots to young parts of the tree, associated with a redistribution of calcium formerly fixed in tissues; 2. in June-July, an equilibrium in mineral exchanges between the different parts of the tree; 3. from early august to end of October, a pre-dormancy phase marked by a slowing of translocation; 4. in november-december, an absolute dormancy period; 5. from January to march, a post-dormancy phase in which root absorption and translocation to aerial parts recover. In outdoors conditions and for a determined climate these stages start and end on dates linked to species and variety: - in Grenoble, absolute dormancy starts in September for thuyas, early October for maple-trees, middle October for norway spruce and novembers for poplars. (authors) [fr

Daily and seasonal rhythms in immune responses of splenocytes in the freshwater snake, Natrix piscator.

Science.gov (United States)

Tripathi, Manish Kumar; Singh, Ramesh; Pati, Atanu Kumar

2015-01-01

Present study was designed to examine daily and seasonal variability in the innate immune responses of splenocytes in the fresh water snake, Natrix piscator. Animals were mildly anesthetized and spleen was aseptically isolated and processed for macrophage phagocytosis, NBT reduction, nitrite production, splenocyte proliferation and serum lysozyme activity. Samples were collected at seven time points, viz., 0000, 0400, 0800, 1200, 1600, 2000 and 0000 h during three different seasons, namely summer, winter and spring. Cosinor analysis revealed that percent phagocytosis had a significant 24-h rhythm during summer and spring seasons. The peaks of rhythms in NBT reduction and nitrite release occurred in the morning hours at 10.88 h and 8.31 h, respectively, in winter. A significant 24-h rhythm was also observed in lysozyme concentration and splenocyte proliferation (both Basal and Concanavalin A stimulated) in all three seasons. A significant phase shift in splenocyte proliferation was obtained with a trend of delayed phase shift from winter to spring and from spring to summer. Of the nine variables, significant annual (seasonal) rhythms were detected in almost all variables, excluding phagocytic and splenosomatic indices. All rhythmic variables, except spleen cellularity, exhibited tightly synchronized peaks coinciding with the progressive and recrudescence phases of annual reproductive cycle. It is concluded that the snake synchronizes its daily and seasonal immune activity with the corresponding external time cues. The enhancement of immune function coinciding with one of its crucial reproductive phases might be helping it to cope with the seasonal stressors, including abundance of pathogens, which would otherwise jeopardize the successful reproduction and eventual survival of the species.

[The influence of interfered circadian rhythm on pregnancy and neonatal rats].

Science.gov (United States)

Chen, Wen-Jun; Sheng, Wen-Jie; Guo, Yin-Hua; Tan, Yong

2015-10-25

The aim of this study was to observe the influence of interfered circadian rhythm on pregnancy of rats and growth of neonatal rats, and to explore the relationship between the interfered circadian rhythm and the changes of melatonin and progesterone. Continuous light was used to inhibit melatonin secretion and therefore the interfered circadian rhythm animal model was obtained. The influence of interfered circadian rhythm on delivery of pregnant rats was observed. Serum was collected from rats during different stages of pregnancy to measure the concentrations of melatonin and progesterone. In order to observe the embryo resorption rate, half of pregnant rats were randomly selected to undergo a laparotomy, and the remainder was used to observe delivery and assess the growth of neonatal rats after delivery. The results showed that the interfered circadian rhythm induced adverse effects on pregnancy outcomes, including an increase of embryo resorption rate and a decrease in the number of live births; inhibited the secretion of melatonin along with decreased serum progesterone level; prolonged the stage of labor, but not the duration of pregnancy; and disturbed the fetal intrauterine growth and the growth of neonatal rats. The results suggest that interfered circadian rhythm condition made by continuous light could make adverse effects on both pregnant rats and neonatal rats. The results of our study may provide a way to modulate pregnant women's circadian rhythm and a possibility of application of melatonin on pregnant women.

The aesthetic value of the golden ratio and rhythm of the photographs

Directory of Open Access Journals (Sweden)

Ivan Budimir

2015-05-01

Full Text Available The study analyzes the aesthetic value of rhythm of the photos as opposed to the form in which the rhythm is subjected. With the method of experimental aesthetics, the visual aesthetics experiment is conducted in which the tested quality of the different forms of proportional rhythm due to the shape and length of the interval as a part of the rhythmic matrix. The experimental part consisted of an assessment of visual quality of the 5 photos containing different variations of proportional rate. On all the photographs the rhythm is constituted of cigarettes situated on the surface of the old concrete. Spacing between cigarettes and interval length is successively reduced to accurately defined proportions. In one photograph, the relations between the neighboring intervals are in line with the ratio of the golden section. The experiment involved 32 subjects who had the task of assessing the level of the aesthetic qualities of rhythm on the Likert scale from 1 to 5 where the grades cannot be repeated. Measurement of the quality of a particular form of rhythm is defined as the arithmetic mean score of all respondents. The highest mean is given to the test image with uniform rhythm when the second place is reserved for a photograph whose rhythm is aligned with the golden section. Conducted analysis of repeated measures ANOVA showed that the obtained arithmetic means differ significantly (F = 3.430, p = 0.011 with a significance level of p 0.05.

Recent Advances in Circadian Rhythms in Cardiovascular System

Directory of Open Access Journals (Sweden)

Lihong eChen

2015-04-01

Full Text Available Growing evidence shows that intrinsic circadian clocks are tightly related to cardiovascular functions. The diurnal changes in blood pressure and heart rate are well known circadian rhythms. Endothelial function, platelet aggregation and thrombus formation exhibit circadian changes as well. The onset of many cardiovascular diseases (CVDs or events, such as myocardial infarction, stroke, arrhythmia, and sudden cardiac death, also exhibits temporal trends. Furthermore, there is strong evidence from animal models and epidemiological studies showing that disruption of circadian rhythms is a significant risk factor for many CVDs, and the intervention of CVDs may have a time dependent effect. In this mini review, we summarized recent advances in our understanding of the relationship between circadian rhythm and cardiovascular physiology and diseases including blood pressure regulation and myocardial infarction.

Crosslinguistic Application of English-Centric Rhythm Descriptors in Motor Speech Disorders

Science.gov (United States)

Liss, Julie M.; Utianski, Rene; Lansford, Kaitlin

2014-01-01

Background Rhythmic disturbances are a hallmark of motor speech disorders, in which the motor control deficits interfere with the outward flow of speech and by extension speech understanding. As the functions of rhythm are language-specific, breakdowns in rhythm should have language-specific consequences for communication. Objective The goals of this paper are to (i) provide a review of the cognitive- linguistic role of rhythm in speech perception in a general sense and crosslinguistically; (ii) present new results of lexical segmentation challenges posed by different types of dysarthria in American English, and (iii) offer a framework for crosslinguistic considerations for speech rhythm disturbances in the diagnosis and treatment of communication disorders associated with motor speech disorders. Summary This review presents theoretical and empirical reasons for considering speech rhythm as a critical component of communication deficits in motor speech disorders, and addresses the need for crosslinguistic research to explore language-universal versus language-specific aspects of motor speech disorders. PMID:24157596

The full moon as a synchronizer of circa-monthly biological rhythms: Chronobiologic perspectives based on multidisciplinary naturalistic research.

Science.gov (United States)

Reinberg, Alain; Smolensky, Michael H; Touitou, Yvan

Biological rhythmicity is presumed to be an advantageous genetic adaptation of fitness and survival value resulting from evolution of life forms in an environment that varies predictably-in-time during the 24 h, month, and year. The 24 h light/dark cycle is the prime synchronizer of circadian periodicities, and its modulation over the course of the year, in terms of daytime photoperiod length, is a prime synchronizer of circannual periodicities. Circadian and circannual rhythms have been the major research focus of most scientists. Circa-monthly rhythms triggered or synchronized by the 29.5 day lunar cycle of nighttime light intensity, or specifically the light of the full moon, although explored in waterborne and certain other species, have received far less study, perhaps because of associations with ancient mythology and/or an attitude naturalistic studies are of lesser merit than ones that entail molecular mechanisms. In this editorial, we cite our recent discovery through multidisciplinary naturalistic investigation of a highly integrated circadian, circa-monthly, and circannual time structure, synchronized by the natural ambient nyctohemeral, lunar, and annual light cycles, of the Peruvian apple cactus (C. peruvianus) flowering and reproductive processes that occur in close temporal coordination with like rhythms of the honey bee as its pollinator. This finding led us to explore the preservation of this integrated biological time structure, synchronized and/or triggered by environmental light cues and cycles, in the reproduction of other species, including Homo sapiens, and how the artificial light environment of today in which humans reside may be negatively affecting human reproduction efficiency.

Sustained Accelerated Idioventricular Rhythm in a Centrifuge-Simulated Suborbital Spaceflight.

Science.gov (United States)

Suresh, Rahul; Blue, Rebecca S; Mathers, Charles; Castleberry, Tarah L; Vanderploeg, James M

2017-08-01

Hypergravitational exposures during human centrifugation are known to provoke dysrhythmias, including sinus dysrhythmias/tachycardias, premature atrial/ventricular contractions, and even atrial fibrillations or flutter patterns. However, events are generally short-lived and resolve rapidly after cessation of acceleration. This case report describes a prolonged ectopic ventricular rhythm in response to high G exposure. A previously healthy 30-yr-old man voluntarily participated in centrifuge trials as a part of a larger study, experiencing a total of 7 centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak +3.5 Gz, run 2) and two +Gx runs (peak +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Hemodynamic data collected included blood pressure, heart rate, and continuous three-lead electrocardiogram. Following the final acceleration exposure of the last Day 2 run (peak +4.5 Gx and +4.0 Gz combined, resultant +6.0 G), during a period of idle resting centrifuge activity (resultant vector +1.4 G), the subject demonstrated a marked change in his three-lead electrocardiogram from normal sinus rhythm to a wide-complex ectopic ventricular rhythm at a rate of 91-95 bpm, consistent with an accelerated idioventricular rhythm (AIVR). This rhythm was sustained for 2 m, 24 s before reversion to normal sinus. The subject reported no adverse symptoms during this time. While prolonged, the dysrhythmia was asymptomatic and self-limited. AIVR is likely a physiological response to acceleration and can be managed conservatively. Vigilance is needed to ensure that AIVR is correctly distinguished from other, malignant rhythms to avoid inappropriate treatment and negative operational impacts.Suresh R, Blue RS, Mathers C, Castleberry TL, Vanderploeg JM. Sustained accelerated idioventricular rhythm in a centrifuge-simulated suborbital spaceflight. Aerosp Med Hum Perform. 2017; 88(8):789-793.

The maturation of cortical sleep rhythms and networks over early development

OpenAIRE

Chu, Catherine Jean; Leahy, J.; Pathmanathan, Jay Sriram; Kramer, M.A.; Cash, Sydney S.

2014-01-01

Objective: Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development. Methods: We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state. ...

The Impact of Instrument-Specific Musical Training on Rhythm Perception and Production.

Science.gov (United States)

Matthews, Tomas E; Thibodeau, Joseph N L; Gunther, Brian P; Penhune, Virginia B

2016-01-01

Studies comparing musicians and non-musicians have shown that musical training can improve rhythmic perception and production. These findings tell us that training can result in rhythm processing advantages, but they do not tell us whether practicing a particular instrument could lead to specific effects on rhythm perception or production. The current study used a battery of four rhythm perception and production tasks that were designed to test both higher- and lower-level aspects of rhythm processing. Four groups of musicians (drummers, singers, pianists, string players) and a control group of non-musicians were tested. Within-task differences in performance showed that factors such as meter, metrical complexity, tempo, and beat phase significantly affected the ability to perceive and synchronize taps to a rhythm or beat. Musicians showed better performance on all rhythm tasks compared to non-musicians. Interestingly, our results revealed no significant differences between musician groups for the vast majority of task measures. This was despite the fact that all musicians were selected to have the majority of their training on the target instrument, had on average more than 10 years of experience on their instrument, and were currently practicing. These results suggest that general musical experience is more important than specialized musical experience with regards to perception and production of rhythms.

The impact of instrument-specific musical training on rhythm perception and production

Directory of Open Access Journals (Sweden)

Tomas Edward Matthews

2016-02-01

Full Text Available Various studies have shown that musical training can improve rhythmic perception and production. These findings tell us that music training can result in rhythm processing advantages but they do not tell us whether practicing a particular instrument could lead to specific effects on rhythm perception or production. The current study used a battery of four rhythm perception and production tasks that were designed to test both higher- and lower-level aspects of rhythm processing. Four groups of musicians (drummers, singers, pianists, string players and a control group of non-musicians were tested. Within-task differences in performance showed that factors such as meter, metrical complexity, tempo and beat phase significantly affected the ability to perceive and synchronize taps to a rhythm or beat. Musicians showed better performance on all rhythm tasks compared to non-musicians. Interestingly, our results revealed no significant differences between musician groups for the vast majority of task measures. This is despite the fact that all musicians were selected to have the majority of their training on the target instrument, had on average more than ten years of experience on their instrument, and were currently practicing. These results suggest that general musical experience is more important than specialized musical experience with regards to perception and production of rhythms.

Find a Heart Rhythm Specialist

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Endogenous Prospect Theory

OpenAIRE

Schmidt, Ulrich; Zank, Horst

2010-01-01

In previous models of (cumulative) prospect theory reference-dependence of preferences is imposed beforehand and the location of the reference point is exogenously determined. This paper provides an axiomatization of a new specification of cumulative prospect theory, termed endogenous prospect theory, where reference-dependence is derived from preference conditions and a unique reference point arises endogenously.

Quantitative tissue-specific dynamics of in vivo GILZ mRNA expression and regulation by endogenous and exogenous glucocorticoids.

Science.gov (United States)

Ayyar, Vivaswath S; Almon, Richard R; Jusko, William J; DuBois, Debra C

2015-06-01

Glucocorticoids (GC) are steroid hormones, which regulate metabolism and immune function. Synthetic GCs, or corticosteroids (CS), have appreciable clinical utility via their ability to suppress inflammation in immune-mediated diseases like asthma and rheumatoid arthritis. Recent work has provided insight to novel GC-induced genes that mediate their anti-inflammatory effects, including glucocorticoid-induced leucine zipper (GILZ). Since GILZ comprises an important part of GC action, its regulation by both drug and hormone will influence CS therapy. In addition, GILZ expression is often employed as a biomarker of GC action, which requires judicious selection of sampling time. Understanding the in vivo regulation of GILZ mRNA expression over time will provide insight into both the physiological regulation of GILZ by endogenous GC and the dynamics of its enhancement by CS. A highly quantitative qRT-PCR assay was developed for measuring GILZ mRNA expression in tissues obtained from normal and CS-treated rats. This assay was applied to measure GILZ mRNA expression in eight tissues; to determine its endogenous regulation over time; and to characterize its dynamics in adipose tissue, muscle, and liver following treatment with CS. We demonstrate that GILZ mRNA is expressed in several tissues. GILZ mRNA expression in adipose tissue displayed a robust circadian rhythm that was entrained with the circadian oscillation of endogenous corticosterone; and is strongly enhanced by acute and chronic dosing. Single dosing also enhanced GILZ mRNA in muscle and liver, but the dynamics varied. In conclusion, GILZ is widely expressed in the rat and highly regulated by endogenous and exogenous GCs. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Biological Clocks & Circadian Rhythms

Science.gov (United States)

Robertson, Laura; Jones, M. Gail

2009-01-01

The study of biological clocks and circadian rhythms is an excellent way to address the inquiry strand in the National Science Education Standards (NSES) (NRC 1996). Students can study these everyday phenomena by designing experiments, gathering and analyzing data, and generating new experiments. As students explore biological clocks and circadian…

Endogenous Turnover of Cyanogenic Glycosides in Plants

DEFF Research Database (Denmark)

Picmanova, Martina

, there is strong evidence that CNglcs serve a no less significant purpose as a transport and storage form of reduced nitrogen which may be remobilized and recycled to balance the needs of primary metabolism during certain developmental events. Reduced nitrogen from CNglcs may be recovered either via HCN refixation...... revealed the formation of glycosides of amides, carboxylic acids and "anitriles", including their di- and triglycosides, evidently derived from CNglcs. Based on results common to the three phylogenetically unrelated plant species, a recycling endogenous turnover pathway for CNglcs was suggested in which...

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers.

Science.gov (United States)

Yon, Felipe; Joo, Youngsung; Cortés Llorca, Lucas; Rothe, Eva; Baldwin, Ian T; Kim, Sang-Gyu

2016-02-01

The rhythmic opening/closing and volatile emissions of flowers are known to attract pollinators at specific times. That these rhythms are maintained under constant light or dark conditions suggests a circadian clock involvement. Although a forward and reverse genetic approach has led to the identification of core circadian clock components in Arabidopsis thaliana, the involvement of these clock components in floral rhythms has remained untested, probably because of the weak diurnal rhythms in A. thaliana flowers. Here, we addressed the role of these core clock components in the flowers of the wild tobacco Nicotiana attenuata, whose flowers open at night, emit benzyl acetone (BA) scents and move vertically through a 140° arc. We first measured N. attenuata floral rhythms under constant light conditions. The results suggest that the circadian clock controls flower opening, BA emission and pedicel movement, but not flower closing. We generated transgenic N. attenuata lines silenced in the homologous genes of Arabidopsis LATE ELONGATED HYPOCOTYL (LHY) and ZEITLUPE (ZTL), which are known to be core clock components. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

An analysis of heart rhythm dynamics using a three-coupled oscillator model

International Nuclear Information System (INIS)

Gois, Sandra R.F.S.M.; Savi, Marcelo A.

2009-01-01

Rhythmic phenomena represent one of the most striking manifestations of the dynamic behavior in biological systems. Understanding the mechanisms responsible for biological rhythms is crucial for the comprehension of the dynamics of life. Natural rhythms could be either regular or irregular over time and space. Each kind of dynamical behavior may be related to both normal and pathological physiological functioning. The cardiac conducting system can be treated as a network of self-excitatory elements and, since these elements exhibit oscillatory behavior, they can be modeled as nonlinear oscillators. This paper proposes a mathematical model to describe heart rhythms considering three modified Van der Pol oscillators connected with time delay couplings. Therefore, the heart dynamics is represented by a system of differential difference equations. Numerical simulations are carried out presenting qualitative agreement with the general heart rhythm behavior. Normal and pathological rhythms represented by the ECG signals are reproduced. Pathological rhythms are generated by either the coupling alterations that represents communications aspects in the heart electric system or forcing excitation representing external pacemaker excitation.

Comparison of febrile responsiveness of rats and rabbits to endogenous pyrogen.

Science.gov (United States)

Stitt, J T; Shimada, S G; Bernheim, H A

1985-12-01

The fever responses of rats and rabbits were compared in detail using a single common source of semipurified endogenous pyrogen prepared from human monocytes. The characteristics and dynamics of the fever-response curves for each species were examined and their dose-response curves were determined and compared. The fevers displayed by rats were qualitatively similar to those of rabbits, but, typically, they developed and terminated more rapidly than those of rabbits. Rabbits were much more sensitive to the endogenous pyrogen than rats. The threshold dose of pyrogen required to elicit a fever was 5 times lower in the rabbit, and the slope of the rabbit's dose-response curve was 1.5 times steeper than that of the rat. The maximum fevers attainable in rabbits were approximately twice those attainable in rats. It was also shown that the more rapid febrile responses of the rat were not due to the 10-fold smaller mass of the rat; instead, we proposed that this difference was more likely due to a closer diffusional proximity of the pyrogen receptor sites to the circulation in rats. The lower sensitivity of the rat to endogenous pyrogen was attributed to a relative insensitivity of the pyrogen receptor sites in rats in the translation of the endogenous pyrogen stimulus into fever.

Induction of apoptosis in human multiple myeloma cell lines by ebselen via enhancing the endogenous reactive oxygen species production.

Science.gov (United States)

Zhang, Liang; Zhou, Liwei; Du, Jia; Li, Mengxia; Qian, Chengyuan; Cheng, Yi; Peng, Yang; Xie, Jiayin; Wang, Dong

2014-01-01

Ebselen a selenoorganic compound showing glutathione peroxidase like activity is an anti-inflammatory and antioxidative agent. Its cytoprotective activity has been investigated in recent years. However, experimental evidence also shows that ebselen causes cell death in several cancer cell types whose mechanism has not yet been elucidated. In this study, we examined the effect of ebselen on multiple myeloma (MM) cell lines in vitro. The results showed that ebselen significantly enhanced the production of reactive oxygen species (ROS) accompanied by cell viability decrease and apoptosis rate increase. Further studies revealed that ebselen can induce Bax redistribution from the cytosol to mitochondria leading to mitochondrial membrane potential ΔΨm changes and cytochrome C release from the mitochondria to cytosol. Furtherly, we found that exogenous addition of N-acetyl cysteine (NAC) completely diminished the cell damage induced by ebselen. This result suggests that relatively high concentration of ebselen can induce MM cells apoptosis in culture by enhancing the production of endogenous ROS and triggering mitochondria mediated apoptotic pathway.

[Circadian rhythm : Influence on Epworth Sleepiness Scale score].

Science.gov (United States)

Herzog, M; Bedorf, A; Rohrmeier, C; Kühnel, T; Herzog, B; Bremert, T; Plontke, S; Plößl, S

2017-02-01

The Epworth Sleepiness Scale (ESS) is frequently used to determine daytime sleepiness in patients with sleep-disordered breathing. It is still unclear whether different levels of alertness induced by the circadian rhythm influence ESS score. The aim of this study is to investigate the influence of circadian rhythm-dependent alertness on ESS performance. In a monocentric prospective noninterventional observation study, 97 patients with suspected sleep-disordered breathing were investigated with respect to daytime sleepiness in temporal relationship to polysomnographic examination and treatment. The Karolinska Sleepiness Scale (KSS) and the Stanford Sleepiness Scale (SSS) served as references for the detection of present sleepiness at three different measurement times (morning, noon, evening), prior to and following a diagnostic polysomnography night as well as after a continuous positive airway pressure (CPAP) titration night (9 measurements in total). The KSS, SSS, and ESS were performed at these times in a randomized order. The KSS and SSS scores revealed a circadian rhythm-dependent curve with increased sleepiness at noon and in the evening. Following a diagnostic polysomnography night, the scores were increased compared to the measurements prior to the night. After the CPAP titration night, sleepiness in the morning was reduced. KSS and SSS reflect the changes in alertness induced by the circadian rhythm. The ESS score war neither altered by the intra-daily nor by the inter-daily changes in the level of alertness. According to the present data, the ESS serves as a reliable instrument to detect the level of daytime sleepiness independently of the circadian rhythm-dependent level of alertness.

Movement-related theta rhythm in humans: coordinating self-directed hippocampal learning.

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Raphael Kaplan

Full Text Available The hippocampus is crucial for episodic or declarative memory and the theta rhythm has been implicated in mnemonic processing, but the functional contribution of theta to memory remains the subject of intense speculation. Recent evidence suggests that the hippocampus might function as a network hub for volitional learning. In contrast to human experiments, electrophysiological recordings in the hippocampus of behaving rodents are dominated by theta oscillations reflecting volitional movement, which has been linked to spatial exploration and encoding. This literature makes the surprising cross-species prediction that the human hippocampal theta rhythm supports memory by coordinating exploratory movements in the service of self-directed learning. We examined the links between theta, spatial exploration, and memory encoding by designing an interactive human spatial navigation paradigm combined with multimodal neuroimaging. We used both non-invasive whole-head Magnetoencephalography (MEG to look at theta oscillations and Functional Magnetic Resonance Imaging (fMRI to look at brain regions associated with volitional movement and learning. We found that theta power increases during the self-initiation of virtual movement, additionally correlating with subsequent memory performance and environmental familiarity. Performance-related hippocampal theta increases were observed during a static pre-navigation retrieval phase, where planning for subsequent navigation occurred. Furthermore, periods of the task showing movement-related theta increases showed decreased fMRI activity in the parahippocampus and increased activity in the hippocampus and other brain regions that strikingly overlap with the previously observed volitional learning network (the reverse pattern was seen for stationary periods. These fMRI changes also correlated with participant's performance. Our findings suggest that the human hippocampal theta rhythm supports memory by coordinating

Biologic Rhythms Derived from Siberian Mammoths Hairs

Energy Technology Data Exchange (ETDEWEB)

M Spilde; A Lanzirotti; C Qualls; G Phillips; A Ali; L Agenbroad; O Appenzeller

2011-12-31

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

Biologic rhythms derived from Siberian mammoths' hairs.

Directory of Open Access Journals (Sweden)

Mike Spilde

Full Text Available Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios, which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

The Examination of Relationship between Life Rhythm and Parent's Consciousness among Young Children

OpenAIRE

Tanaka, Saori

2008-01-01

The social background of child care and rearing has changed rapidly today in Japan. Also young children's life rhythm has changed compared with before. These disorders of life rhythm cause big influence to young children's mind and body health. To improve young child's mind and body health, it is effective that parents improve the life rhythm at home. Therefore, the educational campaign to parents about young child's life rhythm was held. In this research, the relationship between improvement...

Circadian rhythms of women with fibromyalgia

Science.gov (United States)

Klerman, E. B.; Goldenberg, D. L.; Brown, E. N.; Maliszewski, A. M.; Adler, G. K.

2001-01-01

Fibromyalgia syndrome is a chronic and debilitating disorder characterized by widespread nonarticular musculoskeletal pain whose etiology is unknown. Many of the symptoms of this syndrome, including difficulty sleeping, fatigue, malaise, myalgias, gastrointestinal complaints, and decreased cognitive function, are similar to those observed in individuals whose circadian pacemaker is abnormally aligned with their sleep-wake schedule or with local environmental time. Abnormalities in melatonin and cortisol, two hormones whose secretion is strongly influenced by the circadian pacemaker, have been reported in women with fibromyalgia. We studied the circadian rhythms of 10 women with fibromyalgia and 12 control healthy women. The protocol controlled factors known to affect markers of the circadian system, including light levels, posture, sleep-wake state, meals, and activity. The timing of the events in the protocol were calculated relative to the habitual sleep-wake schedule of each individual subject. Under these conditions, we found no significant difference between the women with fibromyalgia and control women in the circadian amplitude or phase of rhythms of melatonin, cortisol, and core body temperature. The average circadian phases expressed in hours posthabitual bedtime for women with and without fibromyalgia were 3:43 +/- 0:19 and 3:46 +/- 0:13, respectively, for melatonin; 10:13 +/- 0:23 and 10:32 +/- 0:20, respectively for cortisol; and 5:19 +/- 0:19 and 4:57 +/- 0:33, respectively, for core body temperature phases. Both groups of women had similar circadian rhythms in self-reported alertness. Although pain and stiffness were significantly increased in women with fibromyalgia compared with healthy women, there were no circadian rhythms in either parameter. We suggest that abnormalities in circadian rhythmicity are not a primary cause of fibromyalgia or its symptoms.

Wheel-running activity modulates circadian organization and the daily rhythm of eating behavior

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Pendergast, Julie S.; Branecky, Katrina L.; Huang, Roya; Niswender, Kevin D.; Yamazaki, Shin

2014-01-01

Consumption of high-fat diet acutely alters the daily rhythm of eating behavior and circadian organization (the phase relationship between oscillators in central and peripheral tissues) in mice. Voluntary wheel-running activity counteracts the obesogenic effects of high-fat diet and also modulates circadian rhythms in mice. In this study, we sought to determine whether voluntary wheel-running activity could prevent the proximate effects of high-fat diet consumption on circadian organization and behavioral rhythms in mice. Mice were housed with locked or freely rotating running wheels and fed chow or high-fat diet for 1 week and rhythms of locomotor activity, eating behavior, and molecular timekeeping (PERIOD2::LUCIFERASE luminescence rhythms) in ex vivo tissues were measured. Wheel-running activity delayed the phase of the liver rhythm by 4 h in both chow- and high-fat diet-fed mice. The delayed liver phase was specific to wheel-running activity since an enriched environment without the running wheel did not alter the phase of the liver rhythm. In addition, wheel-running activity modulated the effect of high-fat diet consumption on the daily rhythm of eating behavior. While high-fat diet consumption caused eating events to be more evenly dispersed across the 24 h-day in both locked-wheel and wheel-running mice, the effect of high-fat diet was much less pronounced in wheel-running mice. Together these data demonstrate that wheel-running activity is a salient factor that modulates liver phase and eating behavior rhythms in both chow- and high-fat-diet fed mice. Wheel-running activity in mice is both a source of exercise and a self-motivating, rewarding behavior. Understanding the putative reward-related mechanisms whereby wheel-running activity alters circadian rhythms could have implications for human obesity since palatable food and exercise may modulate similar reward circuits. PMID:24624109

A novel animal model linking adiposity to altered circadian rhythms

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Researchers have provided evidence for a link between obesity and altered circadian rhythms (e.g., shift work, disrupted sleep), but the mechanism for this association is still unknown. Adipocytes possess an intrinsic circadian clock, and circadian rhythms in adipocytokines and adipose tissue metab...

Biological Rhythms in the Skin

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Mary S. Matsui

2016-05-01

Full Text Available Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus, which directs an organism’s rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional–translational autoregulatory loops. This master clock, following environmental cues, regulates an organism’s sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin.

Pharmacologic Rhythm Control versus Rate Control in Heart Failure and Atrial Fibrillation

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Gladys Gladys

2017-01-01

Full Text Available Heart failure (HF with atrial fibrillation (AF is correlated with worse prognosis requiring special approach.Rate control has been the first line of treatment in cases of HF and HF. On the other hand, rhythm controlhas been proven to be effective in returning sinus rhythm resulting in better prognosis for patients with HFbut not HF. Its role in cocurring cases of HF and AF is not fully understood. Thus, this study aims to analysewhether pharmacologic rhythm control can be applied to cases of HF and AF to reduce mortality. A searchwas conducted via PubMed, Medline, ProQuest, and Cochrane Database on January 2016. One study wasselected after filtering process by inclusion and exclusion criteria and critical appraisal was performed. It wasfound that there was rhythm control and rate control do no have favouring effect towards mortality shown byRR 1.03 (95% CI 0.90-1.17, p=0.69. Rate control has protective effect towards hospitalizations by RR of 0.92(95% CI 0.86 – 0.98, p=0.008, NNT=19. To conclude, rhythm control is not superior to rate control in reducingmortality and rate control should be still be considered as first line treatment of HF and AF. Keywords: heart failure, pharmacologic rhythm control, rate control, atrial fibrillation   Farmakologis Rhythm Control Dibandingkan dengan Rate Control padaKasus Gagal Jantung dan Atrial Fibrilasi Abstrak Gagal jantung dengan atrial fibrilasi berhubungan dengan prognosis yang lebih buruk dan membutuhkanpenanganan khusus. Saat ini strategi rate control merupakan terapi lini pertama pada kasus gagal jantungdan atrial fibrilasi. Rhythm control memberikan prognosis yang lebih baik pada pasien gagal jantung denganmengembalikan sinus ritme. Kegunaan rhythm control pada kasus gagal jantung dan atrial fibrilasi sampaisaat ini belum sepenuhnya dimengerti. Tujuan studi ini adalah menelaah apakah terapi farmakologis rhythmcontrol dapat menurunkan mortalitas gagal jantung dan atrial fibrilasi. Pencarian data

Rhythmic behaviour of marine benthopelagic species and the synchronous dynamics of benthic communities

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Aguzzi, Jacopo; Sbragaglia, Valerio; Tecchio, Samuele; Navarro, Joan; Company, Joan B.

2015-01-01

Light-intensity cycles drive the relentless motion of species in the oceans, and water column migrants may cyclically make contact with the seabed, hence influencing the temporal dynamism of benthic ecosystems. The influence of light on this process remains largely unknown to date. In this study, we focus on the occurrence of day-night changes in benthic communities on the western Mediterranean continental shelf (100 m depth) and slope (400 m depth) as a potential result of a behaviourally sustained benthopelagic coupling. We analysed fluctuations in species abundance based on trawling at hourly intervals over a 4-day period as a proxy of activity rhythms at the seabed. We also measured light in situ to assess how the depth-related decrease of its intensity influences species rhythms and the occurrence of the putative benthopelagic synchronisation. Temporal similarities in the catch patterns for different species were screened by dendrogram analysis. On the continental shelf, species performing diel migrations (i.e., over a 24 h period) that were either vertical (i.e., benthopelagic) or horizontal across depths (i.e., nektobenthic) clustered together separately from the more sedentary endobenthic and epibenthic species. At the same depth, waveform analysis showed a significant diurnal increase in the catch of water column species and benthic species at night. Such coupling was absent on the continental slope, where light intensity was several orders of magnitude lower than that on the shelf. Our data indicate that diel activity rhythms, which are well known for vertical pelagic migrators, are also evident in the benthos. We discuss the role of light as a major evolutionary driver shaping the composition and biodiversity of benthic communities via visual predation.

Circadian rhythm of the Leydig cells endocrine function is attenuated during aging.

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Baburski, Aleksandar Z; Sokanovic, Srdjan J; Bjelic, Maja M; Radovic, Sava M; Andric, Silvana A; Kostic, Tatjana S

2016-01-01

Although age-related hypofunction of Leydig cells is well illustrated across species, its circadian nature has not been analyzed. Here we describe changes in circadian behavior in Leydig cells isolated from adult (3-month) and aged (18- and 24-month) rats. The results showed reduced circadian pattern of testosterone secretion in both groups of aged rats despite unchanged LH circadian secretion. Although arrhythmic, the expression of Insl3, another secretory product of Leydig cells, was decreased in both groups. Intracellular cAMP and most important steroidogenic genes (Star, Cyp11a1 and Cyp17a1), together with positive steroidogenic regulator (Nur77), showed preserved circadian rhythm in aging although rhythm robustness and expression level were attenuated in both aged groups. Aging compromised cholesterol mobilization and uptake by Leydig cells: the oscillatory transcription pattern of genes encoding HDL-receptor (Scarb1), hormone sensitive lipase (Lipe, enzyme that converts cholesterol esters from lipid droplets into free cholesterol) and protein responsible for forming the cholesterol esters (Soat2) were flattened in 24-month group. The majority of examined clock genes displayed circadian behavior in expression but only a few of them (Bmal1, Per1, Per2, Per3 and Rev-Erba) were reduced in 24-month-old group. Furthermore, aging reduced oscillatory expression pattern of Sirt1 and Nampt, genes encoding key enzymes that connect cellular metabolism and circadian network. Altogether circadian amplitude of Leydig cell's endocrine function decreased during aging. The results suggest that clock genes are more resistant to aging than genes involved in steroidogenesis supporting the hypothesis about peripheral clock involvement in rhythm maintenance during aging. Copyright © 2015 Elsevier Inc. All rights reserved.

Temporal repression of endogenous pluripotency genes during reprogramming of porcine induced pluripotent stem cells

DEFF Research Database (Denmark)

Hall, Vanessa Jane; Christensen, Marianne; Rasmussen, Mikkel Aabech

2012-01-01

Porcine induced pluripotent stem cells (piPSCs) have the capacity to differentiate in vitro and in vivo and form chimeras. However, the lack of transgene silencing of exogenous DNA integrated into the genome and the inability of cells to proliferate in the absence of transgene expression...... pluripotency in the pig. This may help to explain the difficulties in producing stable piPSCs and bona fide embryonic stem cell lines in this species....... transgenes on the expression of the porcine endogenous pluripotency machinery. Endogenous and exogenous gene expression of OCT4, NANOG, SOX2, KLF4, and cMYC was determined at passages 5, 10, 15, and 20, both in cells cultured at 1¿µg/mL doxycycline or 4¿µg/mL doxycycline. Our results revealed that endogenous...

Ecological assessment of seasonal bioclimatic and production rhythms in agrosystems of the Republic of Armenia

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Arsen Grigoryan

2017-06-01

Full Text Available In the article the time features of occurrence of bioclimatic and industrial rhythms according to altitudinal belts are analyzed, a nomogram is composed and spatial and time patterns of rhythms are revealed, the ways of the rational use of seasonal rhythms and greening agrosystems of the Republic of Armenia (RA are shown. The paper summarizes 80–100-year summer monitoring data on onset timing of the main seasonal bioclimatic rhythms of animate and inanimate nature in the RA. The definition of bioclimatic rhythms is given. The importance of studies of seasonal rhythms of nature and society, especially in the non-tropical zones of the Earth is shown. Besides, the special importance of bioclimatic seasonal rhythms' study in order to optimize agro-zootechnical activities and to green agricultural systems is emphasized. Continuous chain of natural rhythms leads to the formation of adequate seasonal rhythms in the production activities of all sectors of the economy, ensuring the functioning of the biosphere and society. The regularities of the timing of seasonal bioclimatic rhythms' onset by the vertical zones in Armenia taking into account the atmospheric moisture of regions is set, vertical gradients are calculated and a nomogram allowing to develop calendars of seasonal works being carried out in certain regions is drawn.

On the origins of endogenous thoughts.

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Tillas, Alexandros

2017-05-01

Endogenous thoughts are thoughts that we activate in a top-down manner or in the absence of the appropriate stimuli. We use endogenous thoughts to plan or recall past events. In this sense, endogenous thinking is one of the hallmarks of our cognitive lives. In this paper, I investigate how it is that we come to possess endogenous control over our thoughts. Starting from the close relation between language and thinking, I look into speech production-a process motorically controlled by the inferior frontal gyrus (IFG). Interestingly, IFG is also closely related to silent talking, as well as volition. The connection between IFG and volition is important given that endogenous thoughts are or at least greatly resemble voluntary actions. Against this background, I argue that IFG is key to understanding the origins of conscious endogenous thoughts. Furthermore, I look into goal-directed thinking and show that IFG plays a key role also in unconscious endogenous thinking.

The effect of lens aging and cataract surgery on circadian rhythm.

Science.gov (United States)

Yan, Shen-Shen; Wang, Wei

2016-01-01

Many organisms have evolved an approximately 24-hour circadian rhythm that allows them to achieve internal physiological homeostasis with external environment. Suprachiasmatic nucleus (SCN) is the central pacemaker of circadian rhythm, and its activity is entrained to the external light-dark cycle. The SCN controls circadian rhythm through regulating the synthesis of melatonin by pineal gland via a multisynaptic pathway. Light, especially short-wavelength blue light, is the most potent environmental time cue in circadian photoentrainment. Recently, the discovery of a novel type of retinal photoreceptors, intrinsically photosensitive retinal ganglion cells, sheds light on the mechanism of circadian photoentrainment and raises concerns about the effect of ocular diseases on circadian system. With age, light transmittance is significantly decreased due to the aging of crystalline lens, thus possibly resulting in progressive loss of circadian photoreception. In the current review, we summarize the circadian physiology, highlight the important role of light in circadian rhythm regulation, discuss about the correlation between age-related cataract and sleep disorders, and compare the effect of blue light- filtering intraocular lenses (IOLs) and ultraviolet only filtering IOLs on circadian rhythm.

Seasonal rhythms of seed rain and seedling emergence in two tropical rain forests in southern Brazil.

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Marques, M C M; Oliveira, P E A M

2008-09-01

Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.

Cycling of clock genes entrained to the solar rhythm enables plants to tell time: data from arabidopsis

Science.gov (United States)

Yeang, Hoong-Yeet

2015-01-01

Background and Aims An endogenous rhythm synchronized to dawn cannot time photosynthesis-linked genes to peak consistently at noon since the interval between sunrise and noon changes seasonally. In this study, a solar clock model that circumvents this limitation is proposed using two daily timing references synchronized to noon and midnight. Other rhythmic genes that are not directly linked to photosynthesis, and which peak at other times, also find an adaptive advantage in entrainment to the solar rhythm. Methods Fourteen datasets extracted from three published papers were used in a meta-analysis to examine the cyclic behaviour of the Arabidopsis thaliana photosynthesis-related gene CAB2 and the clock oscillator genes TOC1 and LHY in T cycles and N–H cycles. Key Results Changes in the rhythms of CAB2, TOC1 and LHY in plants subjected to non-24-h light:dark cycles matched the hypothesized changes in their behaviour as predicted by the solar clock model, thus validating it. The analysis further showed that TOC1 expression peaked ∼5·5 h after mid-day, CAB2 peaked close to noon, while LHY peaked ∼7·5 h after midnight, regardless of the cycle period, the photoperiod or the light:dark period ratio. The solar clock model correctly predicted the zeitgeber timing of these genes under 11 different lighting regimes comprising combinations of seven light periods, nine dark periods, four cycle periods and four light:dark period ratios. In short cycles that terminated before LHY could be expressed, the solar clock correctly predicted zeitgeber timing of its expression in the following cycle. Conclusions Regulation of gene phases by the solar clock enables the plant to tell the time, by which means a large number of genes are regulated. This facilitates the initiation of gene expression even before the arrival of sunrise, sunset or noon, thus allowing the plant to ‘anticipate’ dawn, dusk or mid-day respectively, independently of the photoperiod. PMID:26070640

Maternal exercise, season and sex modify the human fetal circadian rhythm.

Science.gov (United States)

Sletten, Julie; Cornelissen, Germaine; Assmus, Jørg; Kiserud, Torvid; Albrechtsen, Susanne; Kessler, Jörg

2018-05-13

The knowledge on circadian rhythmicity is rapidly expanding. We aimed to define the longitudinal development of the circadian heart rate rhythm in the human fetus in an unrestricted, out-of-hospital setting, and to examine the effects of maternal physical activity, season and fetal sex. We recruited 48 women with low-risk singleton pregnancies. Using a portable monitor for continuous fetal electrocardiography, fetal heart rate recordings were obtained around gestational weeks 24, 28, 32 and 36. Circadian rhythmicity in fetal heart rate and fetal heart rate variation was detected by cosinor analysis; developmental trends were calculated by population-mean cosinor and multilevel analysis. For the fetal heart rate and fetal heart rate variation, a significant circadian rhythm was present in 122/123 (99.2%) and 116/121 (95.9%) of the individual recordings, respectively. The rhythms were best described by combining cosine waves with periods of 24 and 8 hours. With increasing gestational age, the magnitude of the fetal heart rate rhythm increased, and the peak of the fetal heart rate variation rhythm shifted from a mean of 14:25 (24 weeks) to 20:52 (36 weeks). With advancing gestation, the rhythm-adjusted mean value of the fetal heart rate decreased linearly in females (prhythm diversity was found in male fetuses, during higher maternal physical activity and during the summer season. The dynamic development of the fetal circadian heart rate rhythm during the second half of pregnancy is modified by fetal sex, maternal physical activity and season. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Gamification Quest: Rhythm. Music as a game mechanic

OpenAIRE

Granell Díaz, Marina

2017-01-01

Treball Final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2016/2017 This document constitutes the Technical Report for the project Gamification Quest: Rhythm, music as a game mechanic for the Videogame Design and Development bachelor degree. The project consists on the design and implementation of rhythm game mechanics integrated in a gamification environment applied to education. The video game will be implemented on the game engine Unity (10), ...

Interactions between thalamic and cortical rhythms during semantic memory recall in human

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Slotnick, Scott D.; Moo, Lauren R.; Kraut, Michael A.; Lesser, Ronald P.; Hart, John, Jr.

2002-04-01

Human scalp electroencephalographic rhythms, indicative of cortical population synchrony, have long been posited to reflect cognitive processing. Although numerous studies employing simultaneous thalamic and cortical electrode recording in nonhuman animals have explored the role of the thalamus in the modulation of cortical rhythms, direct evidence for thalamocortical modulation in human has not, to our knowledge, been obtained. We simultaneously recorded from thalamic and scalp electrodes in one human during performance of a cognitive task and found a spatially widespread, phase-locked, low-frequency rhythm (7-8 Hz) power decrease at thalamus and scalp during semantic memory recall. This low-frequency rhythm power decrease was followed by a spatially specific, phase-locked, fast-rhythm (21-34 Hz) power increase at thalamus and occipital scalp. Such a pattern of thalamocortical activity reflects a plausible neural mechanism underlying semantic memory recall that may underlie other cognitive processes as well.

Air Travel, Circadian Rhythms/Hormones, and Autoimmunity.

Science.gov (United States)

Torres-Ruiz, J; Sulli, A; Cutolo, M; Shoenfeld, Y

2017-08-01

Biological rhythms are fundamental for homeostasis and have recently been involved in the regulatory processes of various organs and systems. Circadian cycle proteins and hormones have a direct effect on the inflammatory response and have shown pro- or anti-inflammatory effects in animal models of autoimmune diseases. The cells of the immune system have their own circadian rhythm, and the light-dark cycle directly influences the inflammatory response. On the other hand, patients with autoimmune diseases characteristically have sleep disorders and fatigue, and in certain disease, such as rheumatoid arthritis (RA), a frank periodicity in the signs and symptoms is recognized. The joint symptoms predominate in the morning, and apparently, subjects with RA have relative adrenal insufficiency, with a cortisol peak unable to control the late night load of pro-inflammatory cytokines. Transatlantic flights represent a challenge in the adjustment of biological rhythms, since they imply sleep deprivation, time zone changes, and potential difficulties for drug administration. In patients with autoimmune diseases, the use of DMARDs and prednisone at night is probably best suited to lessen morning symptoms. It is also essential to sleep during the trip to improve adaptation to the new time zone and to avoid, as far as possible, works involving flexible or nocturnal shifts. The study of proteins and hormones related to biological rhythms will demonstrate new pathophysiological pathways of autoimmune diseases, which will emphasize the use of general measures for sleep respect and methods for drug administration at key daily times to optimize their anti-inflammatory and immune modulatory effects.

Protection of honeybee Apis mellifera by its endogenous and exogenous lactic flora against bacterial infections

Directory of Open Access Journals (Sweden)

Irakli Janashia

2016-09-01

Three exogenous bacteriocin-producing LAB strains were tested against the same pathogens and against 25 endogenous bacterial isolates representing 11 different LAB species. The screening showed that all the tested exogenous bacteriocin-producing strains inhibited the tested P. larvae strains. The endogenous LAB strains exhibited varied sensitivity profiles when treated with bacteriocin-producing strains. This raises similar challenges to those observed in antibiotic applications leading to dysbacteriosis, even though the efficacy of these bacteriocins against P. larvae in an in vitro system is evident.

SwePep, a database designed for endogenous peptides and mass spectrometry.

Science.gov (United States)

Fälth, Maria; Sköld, Karl; Norrman, Mathias; Svensson, Marcus; Fenyö, David; Andren, Per E

2006-06-01

A new database, SwePep, specifically designed for endogenous peptides, has been constructed to significantly speed up the identification process from complex tissue samples utilizing mass spectrometry. In the identification process the experimental peptide masses are compared with the peptide masses stored in the database both with and without possible post-translational modifications. This intermediate identification step is fast and singles out peptides that are potential endogenous peptides and can later be confirmed with tandem mass spectrometry data. Successful applications of this methodology are presented. The SwePep database is a relational database developed using MySql and Java. The database contains 4180 annotated endogenous peptides from different tissues originating from 394 different species as well as 50 novel peptides from brain tissue identified in our laboratory. Information about the peptides, including mass, isoelectric point, sequence, and precursor protein, is also stored in the database. This new approach holds great potential for removing the bottleneck that occurs during the identification process in the field of peptidomics. The SwePep database is available to the public.

Rhythm and timing in autism: Learning to dance

Directory of Open Access Journals (Sweden)

Pat eAmos

2013-04-01

Full Text Available In recent years, a significant body of research has focused on challenges to neural connectivity as a key to understanding autism. In contrast to attempts to identify a single static, primarily brain-based deficit, children and adults diagnosed with autism are increasingly perceived as out of sync with their internal and external environments in dynamic ways that must also involve operations of the peripheral nervous systems. The noisiness that seems to occur in both directions of neural flow may help explain challenges to movement and sensing, and ultimately to entrainment with circadian rhythms and social interactions. across the autism spectrum. Profound differences in the rhythm and timing of movement have been tracked to infancy. Difficulties with self-synchrony inhibit praxis, and can disrupt the dance of relationships through which caregiver and child build meaning. Different sensory aspects of a situation may fail to match up; ultimately, intentions and actions themselves may be uncoupled. This uncoupling may help explain the expressions of alienation from the actions of one’s body which recur in the autobiographical autism literature. Multi-modal/cross-modal coordination of different types of sensory information into coherent events may be difficult to achieve because amodal properties (e.g. rhythm and tempo that help unite perceptions are unreliable. One question posed to the connectivity research concerns the role of rhythm and timing in this operation, and whether these can be mobilized to reduce overload and enhance performance. A case is made for developmental research addressing how people with autism actively explore and make sense of their environments. The parent/author recommends investigating approaches such as scaffolding interactions via rhythm, following the person’s lead, slowing the pace, discriminating between intentional communication and stray motor patterns, and organizing information through one sensory mode at

Circadian rhythms in healthy aging--effects downstream from the pacemaker

Science.gov (United States)

Monk, T. H.; Kupfer, D. J.

2000-01-01

Using both previously published findings and entirely new data, we present evidence in support of the argument that the circadian dysfunction of advancing age in the healthy human is primarily one of failing to transduce the circadian signal from the circadian timing system (CTS) to rhythms "downstream" from the pacemaker rather than one of failing to generate the circadian signal itself. Two downstream rhythms are considered: subjective alertness and objective performance. For subjective alertness, we show that in both normal nychthemeral (24 h routine, sleeping at night) and unmasking (36 h of constant wakeful bed rest) conditions, advancing age, especially in men, leads to flattening of subjective alertness rhythms, even when circadian temperature rhythms are relatively robust. For objective performance, an unmasking experiment involving manual dexterity, visual search, and visual vigilance tasks was used to demonstrate that the relationship between temperature and performance is strong in the young, but not in older subjects (and especially not in older men).

Biological rhythm in 1/f fluctuations of heart rate in asthmatic children

Directory of Open Access Journals (Sweden)

Norio Kazuma

2004-01-01

Conclusion: During an asthma attack, the rhythm of 1/f fluctuations is ultradian (cycle length under 20 h, compared with various rhythms during a non-attack period. In future, we will clarify the relevance of the ultradian rhythm of 1/f fluctuations over a 24 h period and the biological life-support system at a point of time of an asthma attack.

Rhythm-based segmentation of Popular Chinese Music

DEFF Research Database (Denmark)

Jensen, Karl Kristoffer

2005-01-01

We present a new method to segment popular music based on rhythm. By computing a shortest path based on the self-similarity matrix calculated from a model of rhythm, segmenting boundaries are found along the di- agonal of the matrix. The cost of a new segment is opti- mized by matching manual...... and automatic segment boundaries. We compile a small song database of 21 randomly selected popular Chinese songs which come from Chinese Mainland, Taiwan and Hong Kong. The segmenting results on the small corpus show that 78% manual segmentation points are detected and 74% auto- matic segmentation points...

Circadian rhythm asynchrony in man during hypokinesis.

Science.gov (United States)

Winget, C. M.; Vernikos-Danellis, J.; Cronin, S. E.; Leach, C. S.; Rambaut, P. C.; Mack, P. B.

1972-01-01

Posture and exercise were investigated as synchronizers of certain physiologic rhythms in eight healthy male subjects in a defined environment. Four subjects exercised during bed rest. Body temperature (BT), heart rate, plasma thyroid hormone, and plasma steroid data were obtained from the subjects for a 6-day ambulatory equilibration period before bed rest, 56 days of bed rest, and a 10-day recovery period after bed rest. The results indicate that the mechanism regulating the circadian rhythmicity of the cardiovascular system is rigorously controlled and independent of the endocrine system, while the BT rhythm is more closely aligned to the endocrine system.

Circadian rhythms in mitochondrial respiration

NARCIS (Netherlands)

de Goede, Paul; Wefers, Jakob; Brombacher, Eline Constance; Schrauwen, P; Kalsbeek, A.

2018-01-01

Many physiological processes are regulated with a 24h periodicity to anticipate the environmental changes of day to nighttime and vice versa. These 24h regulations, commonly termed circadian rhythms, amongst others control the sleep-wake cycle, locomotor activity and preparation for food

Habits, aspirations and endogenous fertility

OpenAIRE

Luciano Fanti

2012-01-01

Motivated by the increasing literature on endogenous preferences as well as on endogenous fertility, this paper investigates the implications of the interaction of the endogenous determination of the number of children with habit and aspiration formation in an OLG model. In contrast with the previous literature, we show that greater aspirations may lead to higher savings, and more interestingly, always increase the neoclassical economic growth.

Enhanced timing abilities in percussionists generalize to rhythms without a musical beat.

Science.gov (United States)

Cameron, Daniel J; Grahn, Jessica A

2014-01-01

The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

Enhanced Timing Abilities in Percussionists Generalize to Rhythms Without a Musical Beat

Directory of Open Access Journals (Sweden)

Daniel J Cameron

2014-12-01

Full Text Available The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played, continuation of the beat (as a second sequence was introduced and played simultaneously, and switching to a second beat (the initial sequence finished, leaving only the second. The metres of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals. In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists’ superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

The evolution of rhythm cognition: Timing in music and speech

NARCIS (Netherlands)

Ravignani, A.; Honing, H.; Kotz, S.A.

This editorial serves a number of purposes. First, it aims at summarizing and discussing 33 accepted contributions to the special issue ‘The evolution of rhythm cognition: Timing in music and speech’. The major focus of the issue is the cognitive neuroscience of rhythm, intended as a neurobehavioral

Interaction with Mass Media: The Importance of Rhythm and Tempo.

Science.gov (United States)

Snow, Robert P.

1987-01-01

Stresses that understanding the impact of interaction with mass media requires conceptualizing media as an institutionalized social form. A critical feature of this process is the grammatical character of media interaction in the form of rhythm and tempo, because these rhythms and tempos become established in everyday routine. (SKC)

Circadian Rhythm Control: Neurophysiological Investigations

Science.gov (United States)

Glotzbach, S. F.

1985-01-01

The suprachiasmatic nucleus (SCN) was implicated as a primary component in central nervous system mechanisms governing circadian rhythms. Disruption of the normal synchronization of temperature, activity, and other rhythms is detrimental to health. Sleep wake disorders, decreases in vigilance and performance, and certain affective disorders may result from or be exacerbated by such desynchronization. To study the basic neurophysiological mechanisms involved in entrainment of circadian systems by the environment, Parylene-coated, etched microwire electrode bundles were used to record extracellular action potentials from the small somata of the SCN and neighboring hypothalamic nuclei in unanesthetized, behaving animals. Male Wistar rats were anesthetized and chronically prepared with EEG ane EMG electrodes in addition to a moveable microdrive assembly. The majority of cells had firing rates 10 Hz and distinct populations of cells which had either the highest firing rate or lowest firing rate during sleep were seen.

The Clock gene clone and its circadian rhythms in Pelteobagrus vachelli

Science.gov (United States)

Qin, Chuanjie; Shao, Ting

2015-05-01

The Clock gene, a key molecule in circadian systems, is widely distributed in the animal kingdom. We isolated a 936-bp partial cDNA sequence of the Clock gene ( Pva-clock) from the darkbarbel catfish Pelteobagrus vachelli that exhibited high identity with Clock genes of other species of fish and animals (65%-88%). The putative domains included a basic helix-loop-helix (bHLH) domain and two period-ARNT-single-minded (PAS) domains, which were also similar to those in other species of fish and animals. Pva-Clock was primarily expressed in the brain, and was detected in all of the peripheral tissues sampled. Additionally, the pattern of Pva-Clock expression over a 24-h period exhibited a circadian rhythm in the brain, liver and intestine, with the acrophase at zeitgeber time 21:35, 23:00, and 23:23, respectively. Our results provide insight into the function of the molecular Clock of P. vachelli.

Children's Aural and Kinesthetic Understanding of Rhythm: Developing an Instructional Model

Science.gov (United States)

Foley, Adam D.

2013-01-01

The purpose of this study was to develop a deeper understanding of aural and kinesthetic rhythm skill development in elementary school-age children. In this study, I examined my curriculum model for rhythm understanding, which included creating and implementing assessments of movement skills in meter and rhythm. The research questions were: 1.…

Rhythm perturbations in acoustically paced treadmill walking after stroke.

Science.gov (United States)

Roerdink, Melvyn; Lamoth, Claudine J C; van Kordelaar, Joost; Elich, Peter; Konijnenbelt, Manin; Kwakkel, Gert; Beek, Peter J

2009-09-01

In rehabilitation, acoustic rhythms are often used to improve gait after stroke. Acoustic cueing may enhance gait coordination by creating a stable coupling between heel strikes and metronome beats and provide a means to train the adaptability of gait coordination to environmental changes, as required in everyday life ambulation. To examine the stability and adaptability of auditory-motor synchronization in acoustically paced treadmill walking in stroke patients. Eleven stroke patients and 10 healthy controls walked on a treadmill at preferred speed and cadence under no metronome, single-metronome (pacing only paretic or nonparetic steps), and double-metronome (pacing both footfalls) conditions. The stability of auditory-motor synchronization was quantified by the variability of the phase relation between footfalls and beats. In a separate session, the acoustic rhythms were perturbed and adaptations to restore auditory-motor synchronization were quantified. For both groups, auditory-motor synchronization was more stable for double-metronome than single-metronome conditions, with stroke patients exhibiting an overall weaker coupling of footfalls to metronome beats than controls. The recovery characteristics following rhythm perturbations corroborated the stability findings and further revealed that stroke patients had difficulty in accelerating their steps and instead preferred a slower-step response to restore synchronization. In gait rehabilitation practice, the use of acoustic rhythms may be more effective when both footfalls are paced. In addition, rhythm perturbations during acoustically paced treadmill walking may not only be employed to evaluate the stability of auditory-motor synchronization but also have promising implications for evaluation and training of gait adaptations in neurorehabilitation practice.

Circadian Rhythm Management System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The value of measuring sleep-wake cycles is significantly enhanced by measuring other physiological signals that depend on circadian rhythms (such as heart rate and...

Endogenous Monetary Policy Regime Change

OpenAIRE

Troy Davig; Eric M. Leeper

2006-01-01

This paper makes changes in monetary policy rules (or regimes) endogenous. Changes are triggered when certain endogenous variables cross specified thresholds. Rational expectations equilibria are examined in three models of threshold switching to illustrate that (i) expectations formation effects generated by the possibility of regime change can be quantitatively important; (ii) symmetric shocks can have asymmetric effects; (iii) endogenous switching is a natural way to formally model preempt...

Alteration of circadian rhythm during epileptogenesis: implications for the suprachiasmatic nucleus circuits.

Science.gov (United States)

Xiang, Yan; Li, Zhi-Xiao; Zhang, Ding-Yu; He, Zhi-Gang; Hu, Ji; Xiang, Hong-Bing

2017-01-01

It is important to realize that characterization of the circadian rhythm patterns of seizure occurrence can implicate in diagnosis and treatment of selected types of epilepsy. Evidence suggests a role for the suprachiasmatic nucleus (SCN) circuits in overall circadian rhythm and seizure susceptibility both in animals and humans. Thus, we conclude that SCN circuits may exert modifying effects on circadian rhythmicity and neuronal excitability during epileptogenesis. SCN circuits will be studied in our brain centre and collaborating centres to explore further the interaction between the circadian rhythm and epileptic seizures. More and thorough research is warranted to provide insight into epileptic seizures with circadian disruption comorbidities such as disorders of cardiovascular parameters and core body temperature circadian rhythms.

Composition and functional property of photosynthetic pigments under circadian rhythm in the cyanobacterium Spirulina platensis.

Science.gov (United States)

Kumar, Deepak; Kannaujiya, Vinod K; Richa; Pathak, Jainendra; Sundaram, Shanthy; Sinha, Rajeshwar P

2018-05-01

Circadian rhythm is an important endogenous biological signal for sustainable growth and development of cyanobacteria in natural ecosystems. Circadian effects of photosynthetically active radiation (PAR), ultraviolet-A (UV-A) and ultraviolet-B (UV-B) radiations on pigment composition have been studied in the cyanobacterium Spirulina platensis under light (L)/dark (D) oscillation with a combination of 4/20, 8/16, 12/12, 16/8, 20/4 and 24/24 h time duration. Circadian exposure of PAR + UV-A (PA) and PAR + UV-A + UV-B (PAB) showed more than twofold decline in Chl a, total protein and phycocyanin (PC) in light phase and significant recovery was achieved in dark phase. The fluorescence emission wavelength of PC was shifted towards lower wavelengths in the light phase of PAB in comparison to P and PA whereas the same wavelength was retrieved in the dark phase. The production of free radicals was accelerated twofold in the light phase (24 h L) whereas the same was retrieved to the level of control during the dark phase. Oxidatively induced damage was alleviated by antioxidative enzymes such as catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and ascorbate peroxidase (APX) in the light phase (0-24-h L) whereas the dark phase showed significant inhibition of the same enzymes. Similar characteristic inhibition of free radicals and recovery of PC was observed inside cellular filament after circadian rhythm of 24/24 h (L/D). Circadian exposure of P, PA and PAB significantly altered the synthesis and recovery of pigments that could be crucial for optimization and sustainable production of photosynthetic products for human welfare.

Sleep and circadian rhythm disruption in neuropsychiatric illness.

Science.gov (United States)

Jagannath, Aarti; Peirson, Stuart N; Foster, Russell G

2013-10-01

Sleep and circadian rhythm disruption (SCRD) is a common feature in many neuropsychiatric diseases including schizophrenia, bipolar disorder and depression. Although the precise mechanisms remain unclear, recent evidence suggests that this comorbidity is not simply a product of medication or an absence of social routine, but instead reflects commonly affected underlying pathways and mechanisms. For example, several genes intimately involved in the generation and regulation of circadian rhythms and sleep have been linked to psychiatric illness. Further, several genes linked to mental illness have recently been shown to also play a role in normal sleep and circadian behaviour. Here we describe some of the emerging common mechanisms that link circadian rhythms, sleep and SCRD in severe mental illnesses. A deeper understanding of these links will provide not only a greater understanding of disease mechanisms, but also holds the promise of novel avenues for therapeutic intervention. Copyright © 2013. Published by Elsevier Ltd.

A New Perspective for Parkinson's Disease: Circadian Rhythm.

Science.gov (United States)

Li, Siyue; Wang, Yali; Wang, Fen; Hu, Li-Fang; Liu, Chun-Feng

2017-02-01

Circadian rhythm is manifested by the behavioral and physiological changes from day to night, which is controlled by the pacemaker and its regulator. The former is located at the suprachiasmatic nuclei (SCN) in the anterior hypothalamus, while the latter is composed of clock genes present in all tissues. Circadian desynchronization influences normal patterns of day-night rhythms such as sleep and alertness cycles, rest and activity cycles. Parkinson's disease (PD) exhibits diurnal fluctuations. Circadian dysfunction has been observed in PD patients and animal models, which may result in negative consequences to the homeostasis and even exacerbate the disease progression. Therefore, circadian therapies, including light stimulation, physical activity, dietary and social schedules, may be helpful for PD patients. However, the cellular and molecular mechanisms that underlie the circadian dysfunction in PD remain elusive. Further research on circadian patterns is needed. This article summarizes the existing research on the circadian rhythms in PD, focusing on the clinical symptom variations, molecular changes, as well as the available treatment options.

Responses of endogenous proline in rice seedlings under chromium exposure

Directory of Open Access Journals (Sweden)

X.Z. Yu

2016-12-01

Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p

[NEUROSEMANTIC AND PSYCHOPHYSIOLOGICAL CORRELATES OF RHYTHM-SUGGESTIVE CORRECTION OF STRESS CONDITIONS].

Science.gov (United States)

Ushakov, I B; Ivanov, A V; Kvasovets, S V; Bubeev, Yu A

2015-01-01

Correlates of successful rhythm-suggestive compensation of stress in sportsmen with neurotic symptoms developed in consequence of painful experience of failure were studied. Effectiveness of the rhythm-suggestive and rational psychological methods was compared by measuring the evoked potentials response to emotionally significant extramental verbal stimuli and images, and using psychophysiological test MASTER to track dynamics of a number of body functional parameters. The rational compensation has been shown to reduce the psychic tension and to set right the voluntary control process. Rhythm-suggestive programs are good for compensation of post-stress emotions and affectations, and the involuntary control process. It was found that correction potentialities of the rhythm-suggestive programs together with the psychodiagnostic advantages of test MASTER are promising instruments for dynamic monitoring of the mental state with the aim to prevent workplace stresses and to provide rehabilitation treatment of aftermaths.

Endogenous MOV10 inhibits the retrotransposition of endogenous retroelements but not the replication of exogenous retroviruses.

Science.gov (United States)

Arjan-Odedra, Shetal; Swanson, Chad M; Sherer, Nathan M; Wolinsky, Steven M; Malim, Michael H

2012-06-22

The identification of cellular factors that regulate the replication of exogenous viruses and endogenous mobile elements provides fundamental understanding of host-pathogen relationships. MOV10 is a superfamily 1 putative RNA helicase that controls the replication of several RNA viruses and whose homologs are necessary for the repression of endogenous mobile elements. Here, we employ both ectopic expression and gene knockdown approaches to analyse the role of human MOV10 in the replication of a panel of exogenous retroviruses and endogenous retroelements. MOV10 overexpression substantially decreased the production of infectious retrovirus particles, as well the propagation of LTR and non-LTR endogenous retroelements. Most significantly, RNAi-mediated silencing of endogenous MOV10 enhanced the replication of both LTR and non-LTR endogenous retroelements, but not the production of infectious retrovirus particles demonstrating that natural levels of MOV10 suppress retrotransposition, but have no impact on infection by exogenous retroviruses. Furthermore, functional studies showed that MOV10 is not necessary for miRNA or siRNA-mediated mRNA silencing. We have identified novel specificity for human MOV10 in the control of retroelement replication and hypothesise that MOV10 may be a component of a cellular pathway or process that selectively regulates the replication of endogenous retroelements in somatic cells.

Sleep, Rhythms, and the Endocrine Brain: Influence of Sex and Gonadal Hormones

Science.gov (United States)

Mong, Jessica A.; Baker, Fiona C.; Mahoney, Megan M.; Paul, Ketema N.; Schwartz, Michael D.; Semba, Kazue; Silver, Rae

2011-01-01

While much is known about the mechanisms that underlie sleep and circadian rhythms, the investigation into sex differences and gonadal steroid modulation of sleep and biological rhythms is in its infancy. There is a growing recognition of sex disparities in sleep and rhythm disorders. Understanding how neuroendocrine mediators and sex differences influence sleep and biological rhythms is central to advancing our understanding of sleep-related disorders. While it is known that ovarian steroids affect circadian rhythms in rodents, the role of androgen is less understood. Surprising findings that androgens, acting via androgen receptors in the master “circadian clock” within the suprachiasmatic nucleus (SCN), modulate photic effects on activity in males points to novel mechanisms of circadian control. Work in aromatase deficient (ArKO) mice suggests that some sex differences in photic responsiveness are independent of gonadal hormone effects during development. In parallel, aspects of sex differences in sleep are also reported to be independent of gonadal steroids and may involve sex chromosome complement. This a summary of recent work illustrating how sex differences and gonadal hormones influence sleep and circadian rhythms that was presented at a mini-symposium at the 2011 annual meeting of the Society for Neuroscience. PMID:22072663

The rhythm and tempo of the game of highly qualified teams

Directory of Open Access Journals (Sweden)

V’yacheslav Mulik

2015-06-01

Full Text Available Purpose: to set indicators of rhythm and tempo of the game teams of high qualification. Material and Methods: analysis of the scientific-methodical literature, registration of technical-tactical actions, methods of mathematical statistics. The study of competitive activities was conducted with participating teams of world championship 2014. Results: the acticle shows indicators of the rhythm and tempo of the game of well-qualified teams. Conclusions: teams-winners have surpassed teams that concede in terms of indicators of passes the ball, shots at goal, the rhythm of the game, tempo of game.

Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

Science.gov (United States)

Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

2017-01-01

African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

Circadian locomotor rhythms in the cricket, Gryllodes sigillatus. I. Localization of the pacemaker and the photoreceptor.

Science.gov (United States)

Abe, Y; Ushirogawa, H; Tomioka, K

1997-10-01

Circadian locomotor rhythm and its underlying mechanism were investigated in the cricket, Gryllodes sigillatus. Adult male crickets showed a nocturnal locomotor rhythm peaking early in the dark phase of a light to dark cycle. This rhythm persisted under constant darkness (DD) with a free-running period averaging 23.1 +/- 0.3 hr. Although constant bright light made most animals arrhythmic, about 40% of the animals showed free-running rhythms with a period longer than 24 hr under constant dim light condition. On transfer to DD, all arrhythmic animals restored the locomotor rhythm. Bilateral optic nerve severance resulted in free-running of the rhythm even under light-dark cycles. The free-running period of the optic nerve severed animals was significantly longer than sham operated crickets in DD, suggesting that the compound eye plays some role in determining the free-running period. Removal of bilateral lamina-medulla portion of the optic lobe abolished the rhythm under DD. These results demonstrate that the photoreceptor for entrainment is the compound eye and the optic lobe is indispensable for persistence of the rhythm. However, 75% and 54% of the optic lobeless animals showed aberrant rhythms with a period very close to 24 hr under light and temperature cycles, respectively, suggesting that there are neural and/or humoral mechanisms for the aberrant rhythms outside of the optic lobe. Since ocelli removal did not affect the photoperiodically induced rhythm, it is likely that the photoreception for the rhythm is performed through an extraretinal photoreceptor.

Development of a Low-cost, Comprehensive Recording System for Circadian Rhythm Behavior.

Science.gov (United States)

Kwon, Jea; Park, Min Gu; Lee, Seung Eun; Lee, C Justin

2018-02-01

Circadian rhythm is defined as a 24-hour biological oscillation, which persists even without any external cues but also can be re-entrained by various environmental cues. One of the widely accepted circadian rhythm behavioral experiment is measuring the wheel-running activity (WRA) of rodents. However, the price for commercially available WRA recording system is not easily affordable for researchers due to high-cost implementation of sensors for wheel rotation. Here, we developed a cost-effective and comprehensive system for circadian rhythm recording by measuring the house-keeping activities (HKA). We have monitored animal's HKA as electrical signal by simply connecting animal housing cage with a standard analog/digital converter: input to the metal lid and ground to the metal grid floor. We show that acquired electrical signals are combined activities of eating, drinking and natural locomotor behaviors which are well-known indicators of circadian rhythm. Post-processing of measured electrical signals enabled us to draw actogram, which verifies HKA to be reliable circadian rhythm indicator. To provide easy access of HKA recording system for researchers, we have developed user-friendly MATLAB-based software, Circa Analysis. This software provides functions for easy extraction of scalable "touch activity" from raw data files by automating seven steps of post-processing and drawing actograms with highly intuitive user-interface and various options. With our cost-effective HKA circadian rhythm recording system, we have estimated the cost of our system to be less than $150 per channel. We anticipate our system will benefit many researchers who would like to study circadian rhythm.

Nocturnal polyuria is related to absent circadian rhythm of glomerular filtration rate.

Science.gov (United States)

De Guchtenaere, A; Vande Walle, C; Van Sintjan, P; Raes, A; Donckerwolcke, R; Van Laecke, E; Hoebeke, P; Vande Walle, J

2007-12-01

Monosymptomatic nocturnal enuresis is frequently associated with nocturnal polyuria and low urinary osmolality during the night. Initial studies found decreased vasopressin levels associated with low urinary osmolality overnight. Together with the documented desmopressin response, this was suggestive of a primary role for vasopressin in the pathogenesis of enuresis in the absence of bladder dysfunction. Recent studies no longer confirm this primary role of vasopressin. Other pathogenetic factors such as disordered renal sodium handling, hypercalciuria, increased prostaglandins and/or osmotic excretion might have a role. So far, little attention has been given to abnormalities in the circadian rhythm of glomerular filtration rate. We evaluated the circadian rhythm of glomerular filtration rate and diuresis in children with desmopressin resistant monosymptomatic nocturnal enuresis and nocturnal polyuria. We evaluated 15 children (9 boys) 9 to 14 years old with monosymptomatic nocturnal enuresis and nocturnal polyuria resistant to desmopressin treatment. The control group consisted of 25 children (12 boys) 9 to 16 years old with monosymptomatic nocturnal enuresis without nocturnal polyuria. Compared to the control population, children with nocturnal polyuria lost their circadian rhythm not only for diuresis and sodium excretion but also for glomerular filtration rate. Patients with monosymptomatic nocturnal enuresis and nocturnal polyuria lack a normal circadian rhythm for diuresis and sodium excretion, and the circadian rhythm of glomerular filtration rate is absent. This absence of circadian rhythm of glomerular filtration rate and/or sodium handling cannot be explained by a primary role of vasopressin, but rather by a disorder in circadian rhythm of renal glomerular and/or tubular functions.

Endogenous hydrogen peroxide production in the epithelium of the developing embryonic lens.

Science.gov (United States)

Basu, Subhasree; Rajakaruna, Suren; Dickinson, Bryan C; Chang, Christopher J; Menko, A Sue

2014-01-01

Hydrogen peroxide (H2O2) is an endogenously produced reactive oxygen species (ROS) present in a variety of mammalian systems. This particular ROS can play dichotomous roles, being beneficial in some cases and deleterious in others, which reflects the level and location of H2O2 production. While much is known about the redox regulation of ROS by antioxidant and repair systems in the lens, little is known about the endogenous production of H2O2 in embryonic lens tissue or the physiologic relevance of endogenous H2O2 to lens development. This gap in knowledge exists primarily from a lack of reagents that can specifically detect endogenous H2O2 in the intact lens. Here, using a recently developed chemoselective fluorescent boronate probe, peroxyfluor-6 acetoxymethyl ester (PF6-AM), which selectively detects H2O2 over related ROS, we examined the endogenous H2O2 signals in the embryonic lens. Embryonic day 10 chick whole lenses in ex vivo organ culture and lens epithelial cells in primary culture were loaded with the H2O2 probe PF6-AM. To determine the relationship between localization of mitochondria with active membrane potential and the region of H2O2 production in the lens, cells were exposed to the mitochondrial probe MitoTracker Red CMXRos together with PF6-AM. Diphenyleneiodonium (DPI), a flavin inhibitor that blocks generation of intracellular ROS production, was used to confirm that the signal from PF6-AM was due to endogenous ROS production. All imaging was performed by live confocal microscopy. PF6-AM detected endogenous H2O2 in lens epithelial cells in whole lenses in ex vivo culture and in lens epithelial cells grown in primary culture. No endogenous H2O2 signal could be detected in differentiating lens fiber cells with this probe. Treatment with DPI markedly attenuated the fluorescence signal from the peroxide-specific probe PF6-AM in the lens epithelium, suggesting that basal generation of ROS occurs in this region. The lens epithelial cells producing an

Mycobacterium tuberculosis has diminished capacity to counteract redox stress induced by elevated levels of endogenous superoxide.

Science.gov (United States)

Tyagi, Priyanka; Dharmaraja, Allimuthu T; Bhaskar, Ashima; Chakrapani, Harinath; Singh, Amit

2015-07-01

Mycobacterium tuberculosis (Mtb) has evolved protective and detoxification mechanisms to maintain cytoplasmic redox balance in response to exogenous oxidative stress encountered inside host phagocytes. In contrast, little is known about the dynamic response of this pathogen to endogenous oxidative stress generated within Mtb. Using a noninvasive and specific biosensor of cytoplasmic redox state of Mtb, we for first time discovered a surprisingly high sensitivity of this pathogen to perturbation in redox homeostasis induced by elevated endogenous reactive oxygen species (ROS). We synthesized a series of hydroquinone-based small molecule ROS generators and found that ATD-3169 permeated mycobacteria to reliably enhance endogenous ROS including superoxide radicals. When Mtb strains including multidrug-resistant (MDR) and extensively drug-resistant (XDR) patient isolates were exposed to this compound, a dose-dependent, long-lasting, and irreversible oxidative shift in intramycobacterial redox potential was detected. Dynamic redox potential measurements revealed that Mtb had diminished capacity to restore cytoplasmic redox balance in comparison with Mycobacterium smegmatis (Msm), a fast growing nonpathogenic mycobacterial species. Accordingly, Mtb strains were extremely susceptible to inhibition by ATD-3169 but not Msm, suggesting a functional linkage between dynamic redox changes and survival. Microarray analysis showed major realignment of pathways involved in redox homeostasis, central metabolism, DNA repair, and cell wall lipid biosynthesis in response to ATD-3169, all consistent with enhanced endogenous ROS contributing to lethality induced by this compound. This work provides empirical evidence that the cytoplasmic redox poise of Mtb is uniquely sensitive to manipulation in steady-state endogenous ROS levels, thus revealing the importance of targeting intramycobacterial redox metabolism for controlling TB infection. Copyright © 2015 The Authors. Published by

Temporal interactions between cortical rhythms

Directory of Open Access Journals (Sweden)

Anita K Roopun

2008-12-01

Full Text Available Multiple local neuronal circuits support different, discrete frequencies of network rhythm in neocortex. Relationships between different frequencies correspond to mechanisms designed to minimise interference, couple activity via stable phase interactions, and control the amplitude of one frequency relative to the phase of another. These mechanisms are proposed to form a framework for spectral information processing. Individual local circuits can also transform their frequency through changes in intrinsic neuronal properties and interactions with other oscillating microcircuits. Here we discuss a frequency transformation in which activity in two coactive local circuits may combine sequentially to generate a third frequency whose period is the concatenation sum of the original two. With such an interaction, the intrinsic periodicity in each component local circuit is preserved – alternate, single periods of each original rhythm form one period of a new frequency - suggesting a robust mechanism for combining information processed on multiple concurrent spatiotemporal scales.

ENDOGENEITY OF INDONESIAN MONEY SUPPLY

Directory of Open Access Journals (Sweden)

Meutia Safrina Rachma

2011-09-01

Full Text Available There has been a long debate about the endogeneity of money supply. The main objective of this article is to identify whether money supply in Indonesia is an exogenous or an endogenous variable. Using a Vector Autoregressive model and monthly data 1997(5-2010(6, the estimation result shows that money supply in Indonesia is an endogenous variable. The movement of broad money supply does influence the movement of base money and Consumer Price Index. Consequently, the central bank does not have control power on money supply. The bank is only able to maintain the stability and control the movement of broad money supply. Keywords: Endogenous variable, money supply, vector autoregressionJEL classification numbers: E51, E52, E58

Sleep, Memory & Brain Rhythms.

Science.gov (United States)

Watson, Brendon O; Buzsáki, György

2015-01-01

Sleep occupies roughly one-third of our lives, yet the scientific community is still not entirely clear on its purpose or function. Existing data point most strongly to its role in memory and homeostasis: that sleep helps maintain basic brain functioning via a homeostatic mechanism that loosens connections between overworked synapses, and that sleep helps consolidate and re-form important memories. In this review, we will summarize these theories, but also focus on substantial new information regarding the relation of electrical brain rhythms to sleep. In particular, while REM sleep may contribute to the homeostatic weakening of overactive synapses, a prominent and transient oscillatory rhythm called "sharp-wave ripple" seems to allow for consolidation of behaviorally relevant memories across many structures of the brain. We propose that a theory of sleep involving the division of labor between two states of sleep-REM and non-REM, the latter of which has an abundance of ripple electrical activity-might allow for a fusion of the two main sleep theories. This theory then postulates that sleep performs a combination of consolidation and homeostasis that promotes optimal knowledge retention as well as optimal waking brain function.

Resonance of about-weekly human heart rate rhythm with solar activity change.

Science.gov (United States)

Cornelissen, G; Halberg, F; Wendt, H W; Bingham, C; Sothern, R B; Haus, E; Kleitman, E; Kleitman, N; Revilla, M A; Revilla, M; Breus, T K; Pimenov, K; Grigoriev, A E; Mitish, M D; Yatsyk, G V; Syutkina, E V

1996-12-01

In several human adults, certain solar activity rhythms may influence an about 7-day rhythm in heart rate. When no about-weekly feature was found in the rate of change in sunspot area, a measure of solar activity, the double amplitude of a circadian heart rate rhythm, approximated by the fit of a 7-day cosine curve, was lower, as was heart rate corresponds to about-weekly features in solar activity and/or relates to a sunspot cycle.

Endogenous MOV10 inhibits the retrotransposition of endogenous retroelements but not the replication of exogenous retroviruses

Science.gov (United States)

2012-01-01

Background The identification of cellular factors that regulate the replication of exogenous viruses and endogenous mobile elements provides fundamental understanding of host-pathogen relationships. MOV10 is a superfamily 1 putative RNA helicase that controls the replication of several RNA viruses and whose homologs are necessary for the repression of endogenous mobile elements. Here, we employ both ectopic expression and gene knockdown approaches to analyse the role of human MOV10 in the replication of a panel of exogenous retroviruses and endogenous retroelements. Results MOV10 overexpression substantially decreased the production of infectious retrovirus particles, as well the propagation of LTR and non-LTR endogenous retroelements. Most significantly, RNAi-mediated silencing of endogenous MOV10 enhanced the replication of both LTR and non-LTR endogenous retroelements, but not the production of infectious retrovirus particles demonstrating that natural levels of MOV10 suppress retrotransposition, but have no impact on infection by exogenous retroviruses. Furthermore, functional studies showed that MOV10 is not necessary for miRNA or siRNA-mediated mRNA silencing. Conclusions We have identified novel specificity for human MOV10 in the control of retroelement replication and hypothesise that MOV10 may be a component of a cellular pathway or process that selectively regulates the replication of endogenous retroelements in somatic cells. PMID:22727223

Induction of Apoptosis in Human Multiple Myeloma Cell Lines by Ebselen via Enhancing the Endogenous Reactive Oxygen Species Production

Directory of Open Access Journals (Sweden)

Liang Zhang

2014-01-01

Full Text Available Ebselen a selenoorganic compound showing glutathione peroxidase like activity is an anti-inflammatory and antioxidative agent. Its cytoprotective activity has been investigated in recent years. However, experimental evidence also shows that ebselen causes cell death in several cancer cell types whose mechanism has not yet been elucidated. In this study, we examined the effect of ebselen on multiple myeloma (MM cell lines in vitro. The results showed that ebselen significantly enhanced the production of reactive oxygen species (ROS accompanied by cell viability decrease and apoptosis rate increase. Further studies revealed that ebselen can induce Bax redistribution from the cytosol to mitochondria leading to mitochondrial membrane potential ΔΨm changes and cytochrome C release from the mitochondria to cytosol. Furtherly, we found that exogenous addition of N-acetyl cysteine (NAC completely diminished the cell damage induced by ebselen. This result suggests that relatively high concentration of ebselen can induce MM cells apoptosis in culture by enhancing the production of endogenous ROS and triggering mitochondria mediated apoptotic pathway.

Characteristics and classification of hippocampal θ rhythm induced by passive translational displacement.

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Xie, Kangning; Yan, Yili; Fang, Xiaolei; Gao, Shangkai; Hong, Bo

2012-04-25

Theta rhythms in the hippocampus are believed to be the "metric" relating to various behavior patterns for free roaming rats. In this study, the theta rhythms were studied while rats either walked or were passively translated by a toy car on a linear track (referred to as WALK and TRANS respectively). For the similar running speeds in WALK and TRANS conditions, theta frequency and amplitude were both reduced during TRANS. Theta modulation of pyramidal cells during TRANS was reduced compared to that during WALK. Theta frequency was positively correlated with translation speed during TRANS. Theta rhythm remained apparent during TRANS and WALK after large dose of atropine sulfate (blocking the cholinergic pathway) was injected compared to still states. The present study demonstrated the patterns of theta rhythm induced by passive translation in rats and suggested that the Type I theta rhythm could occur during non-voluntary locomotion. We further argued that the perception of actual self-motion may be the underlying mechanism that initiates and modulates type I theta. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Molecular cloning and characterization of the light-regulation and circadian-rhythm of the VDE gene promoter from Zingiber officinale.

Science.gov (United States)

Zhao, Wenchao; Wang, Shaohui; Li, Xin; Huang, Hongyu; Sui, Xiaolei; Zhang, Zhenxian

2012-08-01

Ginger (Zingiber officinale Rosc.) is prone to photoinhibition under intense sunlight. Excessive light can be dissipated by the xanthophyll cycle, where violaxanthin de-epoxidase (VDE) plays a critical role in protecting the photosynthesis apparatus from the damage of excessive light. We isolated ~2.0 kb of ginger VDE (GVDE) gene promoter, which contained the circadian box, I-box, G-box and GT-1 motif. Histochemical staining of Arabidopsis indicated the GVDE promoter was active in almost all organs, especially green tissues. β-glucuronidase (GUS) activity driven by GVDE promoter was repressed rather than activated by high light. GUS activity was altered by hormones, growth regulators and abiotic stresses, which increased with 2,4-dichlorophenoxyacetic acid and decreased with abscisic acid, salicylic acid, zeatin, salt (sodium chloride) and polyethylene glycol. Interestingly, GUS activities with gibberellin or indole-3-acetic acid increased in the short-term (24 h) and decreased in the long-term (48 and 72 h). Analysis of 5' flank deletion found two crucial functional regions residing in -679 to -833 and -63 to -210. Northern blotting analysis found transcription to be regulated by the endogenous circadian clock. Finally, we found a region necessary for regulating the circadian rhythm and another for the basic promoter activity. Key message A novel promoter, named GVDE promoter, was first isolated and analyzed in this study. We have determined one region crucial for promoter activity and another responsible for keeping circadian rhythms.

Weak circadian rhythm increases neutropenia risk among breast cancer patients undergoing adjuvant chemotherapy.

Science.gov (United States)

Li, Wentao; Kwok, Carol Chi-Hei; Chan, Dominic Chun-Wan; Wang, Feng; Tse, Lap Ah

2018-04-01

Severe neutropenia is a common dose-limiting side effect of adjuvant breast cancer chemotherapy. We aimed to test the hypothesis that weak circadian rhythm is associated with an increased risk of neutropenia using a cohort study. We consecutively recruited 193 breast cancer patients who received adjuvant chemotherapy (5-fluorouracil, epirubicin, and cyclophosphamide followed by docetaxel; doxorubicin and cyclophosphamide; docetaxel and cyclophosphamide). Participants wore a wrist actigraph continuously for 168 h at the beginning of chemotherapy. Values of percent rhythm and double amplitude below medians represented weak circadian rhythm. Mesor measured the mean activity level and acrophase symboled the peak time of the rhythm. We used Cox proportional hazard regression model to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) of grade 4 neutropenia and febrile neutropenia in relation to actigraphy-derived parameters. Low levels of percent rhythm (HR:2.59, 95% CI 1.50-4.72), double amplitude (HR:2.70, 95% CI 1.51-4.85), and mesor (HR: 2.48, 95% CI 1.44-4.29) were positively associated with the risk of grade 4 neutropenia during chemotherapy. Low levels of percent rhythm (HR: 2.41, 95% CI 1.02-5.69) and double amplitude (HR:2.49, 95% CI 1.05-5.90) were also associated with increased risks of febrile neutropenia. The HRs for acrophase were not statistically significant. This study provides the first epidemiological evidence that increased risks of grade 4 neutropenia and febrile neutropenia are associated with weak circadian rhythm among adjuvant breast cancer patients. The results suggest that circadian rhythm might be one potential target for the prevention of chemotherapy-induced neutropenia among cancer patients.

Intracerebral evidence of rhythm transform in the human auditory cortex.

Science.gov (United States)

Nozaradan, Sylvie; Mouraux, André; Jonas, Jacques; Colnat-Coulbois, Sophie; Rossion, Bruno; Maillard, Louis

2017-07-01

Musical entrainment is shared by all human cultures and the perception of a periodic beat is a cornerstone of this entrainment behavior. Here, we investigated whether beat perception might have its roots in the earliest stages of auditory cortical processing. Local field potentials were recorded from 8 patients implanted with depth-electrodes in Heschl's gyrus and the planum temporale (55 recording sites in total), usually considered as human primary and secondary auditory cortices. Using a frequency-tagging approach, we show that both low-frequency (30 Hz) neural activities in these structures faithfully track auditory rhythms through frequency-locking to the rhythm envelope. A selective gain in amplitude of the response frequency-locked to the beat frequency was observed for the low-frequency activities but not for the high-frequency activities, and was sharper in the planum temporale, especially for the more challenging syncopated rhythm. Hence, this gain process is not systematic in all activities produced in these areas and depends on the complexity of the rhythmic input. Moreover, this gain was disrupted when the rhythm was presented at fast speed, revealing low-pass response properties which could account for the propensity to perceive a beat only within the musical tempo range. Together, these observations show that, even though part of these neural transforms of rhythms could already take place in subcortical auditory processes, the earliest auditory cortical processes shape the neural representation of rhythmic inputs in favor of the emergence of a periodic beat.

Heart rhythm analysis using ECG recorded with a novel sternum based patch technology

DEFF Research Database (Denmark)

Saadi, Dorthe Bodholt; Fauerskov, Inge; Osmanagic, Armin

2013-01-01

, reliable long-term ECG recordings. The device is designed for high compliance and low patient burden. This novel patch technology is CE approved for ambulatory ECG recording of two ECG channels on the sternum. This paper describes a clinical pilot study regarding the usefulness of these ECG signals...... for heart rhythm analysis. A clinical technician with experience in ECG interpretation selected 200 noise-free 7 seconds ECG segments from 25 different patients. These 200 ECG segments were evaluated by two medical doctors according to their usefulness for heart rhythm analysis. The first doctor considered...... 98.5% of the segments useful for rhythm analysis, whereas the second doctor considered 99.5% of the segments useful for rhythm analysis. The conclusion of this pilot study indicates that two channel ECG recorded on the sternum is useful for rhythm analysis and could be used as input to diagnosis...

REFERENCE MODELS OF ENDOGENOUS ECONOMIC GROWTH

OpenAIRE

GEAMĂNU MARINELA

2012-01-01

The new endogenous growth theories are a very important research area for shaping the most effective policies and long term sustainable development strategies. Endogenous growth theory has emerged as a reaction to the imperfections of neoclassical theory, by the fact that the economic growth is the endogenous product of an economical system.

ENDOGENEITY OF INDONESIAN MONEY SUPPLY

OpenAIRE

Rachma, Meutia Safrina

2011-01-01

There has been a long debate about the endogeneity of money supply. The main objective of this article is to identify whether money supply in Indonesia is an exogenous or an endogenous variable. Using a Vector Autoregressive model and monthly data 1997(5)-2010(6), the estimation result shows that money supply in Indonesia is an endogenous variable. The movement of broad money supply does influence the movement of base money and Consumer Price Index. Consequently, the central bank does not hav...

Endogeneity Of Indonesian Money Supply

OpenAIRE

Rachma, Meutia Safrina

2010-01-01

There has been a long debate about the endogeneity of money supply. The main objective of this article is to identify whether money supply in Indonesia is an exogenous or an endogenous variable. Using a Vector Autoregressive model and monthly data 1997(5)-2010(6), the estimation result shows that money supply in Indonesia is an endogenous variable. The movement of broad money supply does influence the movement of base money and Consumer Price Index. Consequently, the central bank does not hav...

Circadian Rhythm of Glomerular Filtration and Solute Handling Related to Nocturnal Enuresis.

Science.gov (United States)

Dossche, L; Raes, A; Hoebeke, P; De Bruyne, P; Vande Walle, J

2016-01-01

Although nocturnal polyuria in patients with monosymptomatic enuresis can largely be explained by the decreased nocturnal vasopressin secretion hypothesis, other circadian rhythms in the kidney also seem to have a role. We recently documented an absent day/night rhythm in a subgroup of desmopressin refractory cases. We explore the importance of abnormal circadian rhythm of glomerular filtration and tubular (sodium, potassium) parameters in patients with monosymptomatic enuresis. In this retrospective study of a tertiary enuresis population we collected data subsequent to a standardized screening (International Children's Continence Society questionnaire), 14-day diary for nocturnal enuresis and diuresis, and 24-hour concentration profile. The study population consisted of 139 children with nocturnal enuresis who were 5 years or older. Children with nonmonosymptomatic nocturnal enuresis were used as controls. There was a maintained circadian rhythm of glomerular filtration, sodium, osmotic excretion and diuresis rate in children with monosymptomatic and nonmonosymptomatic nocturnal enuresis, and there was no difference between the 2 groups. Secondary analysis revealed that in patients with nocturnal polyuria (with monosymptomatic or nonmonosymptomatic nocturnal enuresis) circadian rhythm of glomerular filtration, sodium and osmotic excretion, and diuresis rate was diminished in contrast to those without nocturnal polyuria (p Circadian rhythm of the kidney does not differ between patients with nonmonosymptomatic and monosymptomatic enuresis. However, the subgroup with enuresis and nocturnal polyuria has a diminished circadian rhythm of nocturnal diuresis, sodium excretion and glomerular filtration in contrast to children without nocturnal polyuria. This observation cannot be explained by the vasopressin theory alone. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Melanopsin resets circadian rhythms in cells by inducing clock gene Period1

Science.gov (United States)

Yamashita, Shuhei; Uehara, Tomoe; Matsuo, Minako; Kikuchi, Yo; Numano, Rika

2014-02-01

The biochemical, physiological and behavioral processes are under the control of internal clocks with the period of approximately 24 hr, circadian rhythms. The expression of clock gene Period1 (Per1) oscillates autonomously in cells and is induced immediately after a light pulse. Per1 is an indispensable member of the central clock system to maintain the autonomous oscillator and synchronize environmental light cycle. Per1 expression could be detected by Per1∷luc and Per1∷GFP plasmid DNA in which firefly luciferase and Green Fluorescence Protein were rhythmically expressed under the control of the mouse Per1 promoter in order to monitor mammalian circadian rhythms. Membrane protein, MELANOPSIN is activated by blue light in the morning on the retina and lead to signals transduction to induce Per1 expression and to reset the phase of circadian rhythms. In this report Per1 induction was measured by reporter signal assay in Per1∷luc and Per1∷GFP fibroblast cell at the input process of circadian rhythms. To the result all process to reset the rhythms by Melanopsin is completed in single cell like in the retina projected to the central clock in the brain. Moreover, the phase of circadian rhythm in Per1∷luc cells is synchronized by photo-activated Melanopsin, because the definite peak of luciferase activity in one dish was found one day after light illumination. That is an available means that physiological circadian rhythms could be real-time monitor as calculable reporter (bioluminescent and fluorescent) chronological signal in both single and groups of cells.

From the Cover: Musical rhythm spectra from Bach to Joplin obey a 1/f power law

Science.gov (United States)

Levitin, Daniel J.; Chordia, Parag; Menon, Vinod

2012-03-01

Much of our enjoyment of music comes from its balance of predictability and surprise. Musical pitch fluctuations follow a 1/f power law that precisely achieves this balance. Musical rhythms, especially those of Western classical music, are considered highly regular and predictable, and this predictability has been hypothesized to underlie rhythm's contribution to our enjoyment of music. Are musical rhythms indeed entirely predictable and how do they vary with genre and composer? To answer this question, we analyzed the rhythm spectra of 1,788 movements from 558 compositions of Western classical music. We found that an overwhelming majority of rhythms obeyed a 1/fβ power law across 16 subgenres and 40 composers, with β ranging from ∼0.5-1. Notably, classical composers, whose compositions are known to exhibit nearly identical 1/f pitch spectra, demonstrated distinctive 1/f rhythm spectra: Beethoven's rhythms were among the most predictable, and Mozart's among the least. Our finding of the ubiquity of 1/f rhythm spectra in compositions spanning nearly four centuries demonstrates that, as with musical pitch, musical rhythms also exhibit a balance of predictability and surprise that could contribute in a fundamental way to our aesthetic experience of music. Although music compositions are intended to be performed, the fact that the notated rhythms follow a 1/f spectrum indicates that such structure is no mere artifact of performance or perception, but rather, exists within the written composition before the music is performed. Furthermore, composers systematically manipulate (consciously or otherwise) the predictability in 1/f rhythms to give their compositions unique identities.

Circadian rhythm disruption was observed in hand, foot, and mouth disease patients.

Science.gov (United States)

Zhu, Yu; Jiang, Zhou; Xiao, Guoguang; Cheng, Suting; Wen, Yang; Wan, Chaomin

2015-03-01

Hand, foot, and mouth disease (HFMD) with central nerve system complications may rapidly progress to fulminated cardiorespiratory failure, with higher mortality and worse prognosis. It has been reported that circadian rhythms of heart rate (HR) and respiratory rate are useful in predicting prognosis of severe cardiovascular and neurological diseases. The present study aims to investigate the characteristics of the circadian rhythms of HR, respiratory rate, and temperature in HFMD patients with neurological complications. Hospitalized HFMD patients including 33 common cases (common group), 61 severe cases (severe group), and 9 critical cases (critical group) were contrasted retrospectively. Their HR, respiratory rate, and temperatures were measured every 4 hours during the first 48-hour in the hospital. Data were analyzed with the least-squares fit of a 24-hour cosine function by the single cosinor and population-mean cosinor method. Results of population-mean cosinor analysis demonstrated that the circadian rhythm of HR, respiratory rate, and temperature was present in the common and severe group, but absent in the critical group. The midline-estimating statistic of rhythm (MESOR) (P = 0.016) and acrophase (P circadian characteristics of HR among 3 groups. Compared with the common group, the MESOR of temperature and respiratory rate was significantly higher, and acrophase of temperature and respiratory rate was 2 hours ahead in the severe group, critical HFMD patients lost their population-circadian rhythm of temperature, HR, and respiratory rate. The high values of temperature and respiratory rate for the common group were concentrated between 3 and 9 PM, whereas those for the severe group were more dispersive. And the high values for the critical group were equally distributed in 24 hours of the day. Circadian rhythm of patients' temperature in the common group was the same as the normal rhythm of human body temperature. Circadian rhythm of patients

Sleep and Sleep-wake Rhythm in Older Adults with Intellectual Disabilities

NARCIS (Netherlands)

E. van de Wouw-Van Dijk (Ellen)

2013-01-01

textabstractEveryone who has experienced poor sleep knows how it affects daytime functioning and wellbeing. A good night’s rest and a stable sleep-wake rhythm are therefore very important. The sleep-wake rhythm is regulated by several brain structures. People with an intellectual disability (ID) all

Endogenous lycopene improves ethanol production under acetic acid stress in Saccharomyces cerevisiae.

Science.gov (United States)

Pan, Shuo; Jia, Bin; Liu, Hong; Wang, Zhen; Chai, Meng-Zhe; Ding, Ming-Zhu; Zhou, Xiao; Li, Xia; Li, Chun; Li, Bing-Zhi; Yuan, Ying-Jin

2018-01-01

Acetic acid, generated from the pretreatment of lignocellulosic biomass, is a significant obstacle for lignocellulosic ethanol production. Reactive oxidative species (ROS)-mediated cell damage is one of important issues caused by acetic acid. It has been reported that decreasing ROS level can improve the acetic acid tolerance of Saccharomyces cerevisiae . Lycopene is known as an antioxidant. In the study, we investigated effects of endogenous lycopene on cell growth and ethanol production of S. cerevisiae in acetic acid media. By accumulating endogenous lycopene during the aerobic fermentation of the seed stage, the intracellular ROS level of strain decreased to 1.4% of that of the control strain during ethanol fermentation. In the ethanol fermentation system containing 100 g/L glucose and 5.5 g/L acetic acid, the lag phase of strain was 24 h shorter than that of control strain. Glucose consumption rate and ethanol titer of yPS002 got to 2.08 g/L/h and 44.25 g/L, respectively, which were 2.6- and 1.3-fold of the control strain. Transcriptional changes of INO1 gene and CTT1 gene confirmed that endogenous lycopene can decrease oxidative stress and improve intracellular environment. Biosynthesis of endogenous lycopene is first associated with enhancing tolerance to acetic acid in S. cerevisiae . We demonstrate that endogenous lycopene can decrease intracellular ROS level caused by acetic acid, thus increasing cell growth and ethanol production. This work innovatively   puts forward a new strategy for second generation bioethanol production during lignocellulosic fermentation.

Electrochemical Detection of Circadian Redox Rhythm in Cyanobacterial Cells via Extracellular Electron Transfer.

Science.gov (United States)

Nishio, Koichi; Pornpitra, Tunanunkul; Izawa, Seiichiro; Nishiwaki-Ohkawa, Taeko; Kato, Souichiro; Hashimoto, Kazuhito; Nakanishi, Shuji

2015-06-01

Recent research on cellular circadian rhythms suggests that the coupling of transcription-translation feedback loops and intracellular redox oscillations is essential for robust circadian timekeeping. For clarification of the molecular mechanism underlying the circadian rhythm, methods that allow for the dynamic and simultaneous detection of transcription/translation and redox oscillations in living cells are needed. Herein, we report that the cyanobacterial circadian redox rhythm can be electrochemically detected based on extracellular electron transfer (EET), a process in which intracellular electrons are exchanged with an extracellular electrode. As the EET-based method is non-destructive, concurrent detection with transcription/translation rhythm using bioluminescent reporter strains becomes possible. An EET pathway that electrochemically connected the intracellular region of cyanobacterial cells with an extracellular electrode was constructed via a newly synthesized electron mediator with cell membrane permeability. In the presence of the mediator, the open circuit potential of the culture medium exhibited temperature-compensated rhythm with approximately 24 h periodicity. Importantly, such circadian rhythm of the open circuit potential was not observed in the absence of the electron mediator, indicating that the EET process conveys the dynamic information regarding the intracellular redox state to the extracellular electrode. These findings represent the first direct demonstration of the intracellular circadian redox rhythm of cyanobacterial cells. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Standing down Straight: Jump Rhythm Technique's Rhythm-Driven, Community-Directed Approach to Dance Education

Science.gov (United States)

Siegenfeld, Billy

2009-01-01

"Standing down straight" means to stand on two feet with both stability and relaxation. Using standing down straight as the foundation of class work, Jump Rhythm Technique offers a fresh alternative to conventional systems of dance study. It bases its pedagogy on three behaviors: grounding the body so that it can move with power and efficiency,…

Sleep and circadian rhythm disturbance in bipolar disorder.

Science.gov (United States)

Bradley, A J; Webb-Mitchell, R; Hazu, A; Slater, N; Middleton, B; Gallagher, P; McAllister-Williams, H; Anderson, K N

2017-07-01

Subjective reports of insomnia and hypersomnia are common in bipolar disorder (BD). It is unclear to what extent these relate to underlying circadian rhythm disturbance (CRD). In this study we aimed to objectively assess sleep and circadian rhythm in a cohort of patients with BD compared to matched controls. Forty-six patients with BD and 42 controls had comprehensive sleep/circadian rhythm assessment with respiratory sleep studies, prolonged accelerometry over 3 weeks, sleep questionnaires and diaries, melatonin levels, alongside mood, psychosocial functioning and quality of life (QoL) questionnaires. Twenty-three (50%) patients with BD had abnormal sleep, of whom 12 (52%) had CRD and 29% had obstructive sleep apnoea. Patients with abnormal sleep had lower 24-h melatonin secretion compared to controls and patients with normal sleep. Abnormal sleep/CRD in BD was associated with impaired functioning and worse QoL. BD is associated with high rates of abnormal sleep and CRD. The association between these disorders, mood and functioning, and the direction of causality, warrants further investigation.

Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

Directory of Open Access Journals (Sweden)

Maria Paula Roncaglia-Denissen

Full Text Available In the current event-related potential (ERP study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first. Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing.

Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

Science.gov (United States)

Roncaglia-Denissen, Maria Paula; Schmidt-Kassow, Maren; Kotz, Sonja A

2013-01-01

In the current event-related potential (ERP) study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first). Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing.

Clinical skills: cardiac rhythm recognition and monitoring.

Science.gov (United States)

Sharman, Joanna

With technological advances, changes in provision of healthcare services and increasing pressure on critical care services, ward patients' severity of illness is ever increasing. As such, nurses need to develop their skills and knowledge to care for their client group. Competency in cardiac rhythm monitoring is beneficial to identify changes in cardiac status, assess response to treatment, diagnosis and post-surgical monitoring. This paper describes the basic anatomy and physiology of the heart and its conduction system, and explains a simple and easy to remember process of analysing cardiac rhythms (Resuscitation Council UK, 2000) that can be used in first-line assessment to assist healthcare practitioners in providing care to their patients.

V3 spinal neurons establish a robust and balanced locomotor rhythm during walking.

Science.gov (United States)

Zhang, Ying; Narayan, Sujatha; Geiman, Eric; Lanuza, Guillermo M; Velasquez, Tomoko; Shanks, Bayle; Akay, Turgay; Dyck, Jason; Pearson, Keir; Gosgnach, Simon; Fan, Chen-Ming; Goulding, Martyn

2008-10-09

A robust and well-organized rhythm is a key feature of many neuronal networks, including those that regulate essential behaviors such as circadian rhythmogenesis, breathing, and locomotion. Here we show that excitatory V3-derived neurons are necessary for a robust and organized locomotor rhythm during walking. When V3-mediated neurotransmission is selectively blocked by the expression of the tetanus toxin light chain subunit (TeNT), the regularity and robustness of the locomotor rhythm is severely perturbed. A similar degeneration in the locomotor rhythm occurs when the excitability of V3-derived neurons is reduced acutely by ligand-induced activation of the allatostatin receptor. The V3-derived neurons additionally function to balance the locomotor output between both halves of the spinal cord, thereby ensuring a symmetrical pattern of locomotor activity during walking. We propose that the V3 neurons establish a regular and balanced motor rhythm by distributing excitatory drive between both halves of the spinal cord.

Core temperature rhythms in normal and tumor-bearing mice.

Science.gov (United States)

Griffith, D J; Busot, J C; Lee, W E; Djeu, D J

1993-01-01

The core temperature temporal behavior of DBA/2 mice (11 normal and 13 with an ascites tumor) was studied using surgically implanted radio telemetry transmitters. Normal mice continuously displayed a stable 24 hour temperature rhythm. Tumor-bearers displayed a progressive deterioration of the temperature rhythm following inoculation with tumor cells. While such disruptions have been noted by others, details on the dynamics of the changes have been mostly qualitative, often due to time-averaging or steady-state analysis of the data. The present study attempts to quantify the dynamics of the disruption of temperature rhythm (when present) by continuously monitoring temperatures over periods up to a month. Analysis indicated that temperature regulation in tumor-bearers was adversely affected during the active period only. Furthermore, it appears that the malignancy may be influencing temperature regulation via pathways not directly attributable to the energy needs of the growing tumor.

Sleep, circadian rhythms, and athletic performance.

Science.gov (United States)

Thun, Eirunn; Bjorvatn, Bjørn; Flo, Elisabeth; Harris, Anette; Pallesen, Ståle

2015-10-01

Sleep deprivation and time of day are both known to influence performance. A growing body of research has focused on how sleep and circadian rhythms impact athletic performance. This review provides a systematic overview of this research. We searched three different databases for articles on these issues and inspected relevant reference lists. In all, 113 articles met our inclusion criteria. The most robust result is that athletic performance seems to be best in the evening around the time when the core body temperature typically is at its peak. Sleep deprivation was negatively associated with performance whereas sleep extension seems to improve performance. The effects of desynchronization of circadian rhythms depend on the local time at which performance occurs. The review includes a discussion of differences regarding types of skills involved as well as methodological issues. Copyright © 2014 Elsevier Ltd. All rights reserved.

Calcium Channel Genes Associated with Bipolar Disorder Modulate Lithium's Amplification of Circadian Rhythms

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McCarthy, Michael J.; LeRoux, Melissa; Wei, Heather; Beesley, Stephen; Kelsoe, John R.; Welsh, David K.

2015-01-01

Bipolar disorder (BD) is associated with mood episodes and low amplitude circadian rhythms. Previously, we demonstrated that fibroblasts grown from BD patients show weaker amplification of circadian rhythms by lithium compared to control cells. Since calcium signals impact upon the circadian clock, and L-type calcium channels (LTCC) have emerged as genetic risk factors for BD, we examined whether loss of function in LTCCs accounts for the attenuated response to lithium in BD cells. We used fluorescent dyes to measure Ca2+ changes in BD and control fibroblasts after lithium treatment, and bioluminescent reporters to measure Per2∷luc rhythms in fibroblasts from BD patients, human controls, and mice while pharmacologically or genetically manipulating calcium channels. Longitudinal expression of LTCC genes (CACNA1C, CACNA1D and CACNB3) was then measured over 12-24 hr in BD and control cells. Our results indicate that independently of LTCCs, lithium stimulated intracellular Ca2+ less effectively in BD vs. control fibroblasts. In longitudinal studies, pharmacological inhibition of LTCCs or knockdown of CACNA1A, CACNA1C, CACNA1D and CACNB3 altered circadian rhythm amplitude. Diltiazem and knockdown of CACNA1C or CACNA1D eliminated lithium's ability to amplify rhythms. Knockdown of CACNA1A or CACNB3 altered baseline rhythms, but did not affect rhythm amplification by lithium. In human fibroblasts, CACNA1C genotype predicted the amplitude response to lithium, and the expression profiles of CACNA1C, CACNA1D and CACNB3 were altered in BD vs. controls. We conclude that in cells from BD patients, calcium signaling is abnormal, and that LTCCs underlie the failure of lithium to amplify circadian rhythms. PMID:26476274

Perceiving Speech Rhythm in Music: Listeners Classify Instrumental Songs According to Language of Origin

Science.gov (United States)

Hannon, Eric E.

2009-01-01

Recent evidence suggests that the musical rhythm of a particular culture may parallel the speech rhythm of that culture's language (Patel, A. D., & Daniele, J. R. (2003). "An empirical comparison of rhythm in language and music." "Cognition, 87," B35-B45). The present experiments aimed to determine whether listeners actually perceive such rhythmic…

Cytokines as endogenous pyrogens.

Science.gov (United States)

Dinarello, C A

1999-03-01

Cytokines are pleiotropic molecules mediating several pathologic processes. Long before the discovery of cytokines as immune system growth factors or as bone marrow stimulants, investigators learned a great deal about cytokines when they studied them as the endogenous mediators of fever. The terms "granulocytic" or "endogenous pyrogen" were used to describe substances with the biologic property of fever induction. Today, we recognize that pyrogenicity is a fundamental biologic property of several cytokines and hence the clinically recognizeable property of fever links host perturbations during disease with fundamental perturbations in cell biology. In this review, the discoveries made on endogenous pyrogens are revisited, with insights into the importance of the earlier work to the present-day understanding of cytokines in health and in disease.

Chapter 11 - Electrical Coupling in the Generation of Vertebrate Motor Rhythms

DEFF Research Database (Denmark)

Li, W.C.; Rekling, Jens Christian

2017-01-01

Many forms of vertebrate motor activity like chewing, breathing, and locomotion are rhythmic. This requires synchronized discharges of motoneurons controlling different muscle groups in an orchestrated manner. We provide a brief review of the presence and role of electrical coupling in a few well...... of electrical coupling in vertebrate motor rhythms appears to be critically dependent on developmental age, with more crucial functions in the early postnatal period than in the adult.......-studied systems: the pacemaker nucleus in weakly electric fish; mesencephalic trigeminal nucleus involved in chewing rhythms; mammalian spinal motoneurons and excitatory interneurons in the Xenopus tadpole swimming circuit, brainstem circuits underlying breathing rhythm, and central respiratory chemosensitivity...

Later endogenous circadian temperature nadir relative to an earlier wake time in older people

Science.gov (United States)

Duffy, J. F.; Dijk, D. J.; Klerman, E. B.; Czeisler, C. A.

1998-01-01

The contribution of the circadian timing system to the age-related advance of sleep-wake timing was investigated in two experiments. In a constant routine protocol, we found that the average wake time and endogenous circadian phase of 44 older subjects were earlier than that of 101 young men. However, the earlier circadian phase of the older subjects actually occurred later relative to their habitual wake time than it did in young men. These results indicate that an age-related advance of circadian phase cannot fully account for the high prevalence of early morning awakening in healthy older people. In a second study, 13 older subjects and 10 young men were scheduled to a 28-h day, such that they were scheduled to sleep at many circadian phases. Self-reported awakening from scheduled sleep episodes and cognitive throughput during the second half of the wake episode varied markedly as a function of circadian phase in both groups. The rising phase of both rhythms was advanced in the older subjects, suggesting an age-related change in the circadian regulation of sleep-wake propensity. We hypothesize that under entrained conditions, these age-related changes in the relationship between circadian phase and wake time are likely associated with self-selected light exposure at an earlier circadian phase. This earlier exposure to light could account for the earlier clock hour to which the endogenous circadian pacemaker is entrained in older people and thereby further increase their propensity to awaken at an even earlier time.

THEORY AND PRACTICE OF RHYTHM IN THE PROFESSIONAL TRAINING SYSTEM FOR ATHLETES AND TEACHING STAFF

Directory of Open Access Journals (Sweden)

Olga Aftimichuk

2015-09-01

Full Text Available Background . Rhythm is important for the implementation of all processes as in nature and in living organisms. It organizes motor human activity making it more productive and rational. On teaching working and sports motions the process of the impellent work correct rhythm assimilation plays an important role because it determines the movement performance optimum that is shown in its automation process reduction. As a result, man’s physical strength and nervous energy are saved. Rhythm category acquires a special status for the physical training specialist. All his activity including the motor component depends on the rhythm. The aim of the research is to study the physiology of rhythm and justify the more efficient training process for future teachers and coaches. Methods . The following theoretical research methods were used: the abstract and axiomatic methods, analysis and synthesis, induction and deduction, idealization, comparison and generalization. Results. As a result of study of materials from the natural sciences, numerology, psychology, music, cybernetics, synergetic, physiology, was found that the change of different states, as in nature and in living organisms, is an undulating rhythmic character. Physiological basis of the same rhythm is dynamic change excitation and inhibition processes occurring in the central nervous system. In this paper features of rhythm were identified. To accelerate the assimilation of motor action rational rhythm it is necessary to develop a sense of rhythm which is successfully formed in during the musical-motor activities. Conclusions. For today the study of the rhythm phenomenon in professional preparation on physical education and sport, in our opinion, requires the further study. Adding exercises involving certain motor skills elements similar in rhythmic structure with professional and technical actions to the coaches and teachers education and the competitive technology formation should be

The daily rhythm of body temperature, heart and respiratory rate in newborn dogs.

Science.gov (United States)

Piccione, Giuseppe; Giudice, Elisabetta; Fazio, Francesco; Mortola, Jacopo P

2010-08-01

We asked whether, during the postnatal period, the daily patterns of body temperature (Tb), heart rate (HR) and breathing frequency (f) begin and develop in synchrony. To this end, measurements of HR, f and Tb were performed weekly, on two consecutive days, for the first two postnatal months on puppies of three breeds of dogs (Rottweiler, Cocker Spaniel and Carlino dogs) with very different birth weights and postnatal growth patterns. Ambient conditions and feeding habits were constant for all puppies. The results indicated that (1) the 24-h average Tb increased and average HR and f decreased with growth, (2) the daily rhythms in Tb were apparent by 4 weeks, irrespective of the puppy's growth pattern, (3) the daily rhythm of Tb in the puppy was not necessarily following that of the mother; in fact, it could anticipate it. (4) The daily rhythms in HR and f were not apparent for the whole study period. We conclude that in neonatal dogs the onset of the daily rhythms of Tb has no obvious relationship with body size or rate of growth and is not cued by the maternal Tb rhythm. The daily rhythms of HR and f do not appear before 2 months of age. Hence, they are not in synchrony with those of Tb.

Rhythm recognition is accountable for the majority of hands-off time during cardiopulmonary resuscitation

DEFF Research Database (Denmark)

Hansen, Lars Koch; Brabrand, Mikkel

2014-01-01

or not was 3.4 s [95% confidence interval (CI): 2.8-3.9] for shockable and 4.4 s (95% CI: 3.6-5.3) for nonshockable rhythms (P4.0 s (95% CI: 3.5-4.5). Of all shockable rhythms, 95.2 % were correctly diagnosed as shockable, compared with 88.6 % of nonshockable rhythms...

Meditations on the unitary rhythm of dying-grieving.

Science.gov (United States)

Malinski, Violet M

2012-07-01

When someone faces loss of a loved one, that person simultaneously grieves and dies a little, just as the one dying also grieves. The author's personal conceptualization of dying and grieving as a unitary rhythm is explored based primarily on her interpretation of Rogers' science of unitary human beings, along with selected examples from related nursing literature and from the emerging focus on continuing bonds in other disciplines. Examples from contemporary songwriters that depict such a unitary conceptualization are given along with personal examples. The author concludes with her description of the unitary rhythm of dying-grieving.

Cortical plasticity induced by short-term multimodal musical rhythm training.

Directory of Open Access Journals (Sweden)

Claudia Lappe

Full Text Available Performing music is a multimodal experience involving the visual, auditory, and somatosensory modalities as well as the motor system. Therefore, musical training is an excellent model to study multimodal brain plasticity. Indeed, we have previously shown that short-term piano practice increase the magnetoencephalographic (MEG response to melodic material in novice players. Here we investigate the impact of piano training using a rhythmic-focused exercise on responses to rhythmic musical material. Musical training with non musicians was conducted over a period of two weeks. One group (sensorimotor-auditory, SA learned to play a piano sequence with a distinct musical rhythm, another group (auditory, A listened to, and evaluated the rhythmic accuracy of the performances of the SA-group. Training-induced cortical plasticity was evaluated using MEG, comparing the mismatch negativity (MMN in response to occasional rhythmic deviants in a repeating rhythm pattern before and after training. The SA-group showed a significantly greater enlargement of MMN and P2 to deviants after training compared to the A- group. The training-induced increase of the rhythm MMN was bilaterally expressed in contrast to our previous finding where the MMN for deviants in the pitch domain showed a larger right than left increase. The results indicate that when auditory experience is strictly controlled during training, involvement of the sensorimotor system and perhaps increased attentional recources that are needed in producing rhythms lead to more robust plastic changes in the auditory cortex compared to when rhythms are simply attended to in the auditory domain in the absence of motor production.

Endogenous growth and the environment

NARCIS (Netherlands)

Withagen, C.A.A.M.; Vellinga, N.

2001-01-01

This paper examines the relationship between environmental policy and growth, from the perspective of endogenous growth theory. In particular three standard endogenous growth models are supplemented with environmental issues, such as pollution and exhaustibility of natural resources. It is found

Endogenous growth and environmental policy

NARCIS (Netherlands)

Withagen, C.A.A.M.; Vellinga, N.

2001-01-01

This paper examines the relationship between environmental policy and growth, from the perspective of endogenous growth theory. In particular three standard endogenous growth models are supplemented with environmental issues, such as pollution and exhaustibility of natural resources. It is found

The maturation of cortical sleep rhythms and networks over early development.

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Chu, C J; Leahy, J; Pathmanathan, J; Kramer, M A; Cash, S S

2014-07-01

Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development. We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state. We found that the emergence of brain rhythms follows a stereotyped sequence over early development. In general, higher frequencies increase in prominence with striking regional specificity throughout development. The coordination of these rhythmic activities across brain regions follows a general pattern of maturation in which broadly distributed networks of low-frequency oscillations increase in density while networks of high frequency oscillations become sparser and more highly clustered. Our results indicate that a predictable program directs the development of key rhythmic components and physiological brain networks over early development. This work expands our knowledge of normal cortical development. The stereotyped neurophysiological processes observed at the level of rhythms and networks may provide a scaffolding to support critical periods of cognitive growth. Furthermore, these conserved patterns could provide a sensitive biomarker for cortical health across development. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Infectious Entry Pathway Mediated by the Human Endogenous Retrovirus K Envelope Protein.

Science.gov (United States)

Robinson, Lindsey R; Whelan, Sean P J

2016-01-20

Endogenous retroviruses (ERVs), the majority of which exist as degraded remnants of ancient viruses, comprise approximately 8% of the human genome. The youngest human ERVs (HERVs) belong to the HERV-K(HML-2) subgroup and were endogenized within the past 1 million years. The viral envelope protein (ENV) facilitates the earliest events of endogenization (cellular attachment and entry), and here, we characterize the requirements for HERV-K ENV to mediate infectious cell entry. Cell-cell fusion assays indicate that a minimum of two events are required for fusion, proteolytic processing by furin-like proteases and exposure to acidic pH. We generated an infectious autonomously replicating recombinant vesicular stomatitis virus (VSV) in which the glycoprotein was replaced by HERV-K ENV. HERV-K ENV imparts an endocytic entry pathway that requires dynamin-mediated membrane scission and endosomal acidification but is distinct from clathrin-dependent or macropinocytic uptake pathways. The lack of impediments to the replication of the VSV core in eukaryotic cells allowed us to broadly survey the HERV-K ENV-dictated tropism. Unlike extant betaretroviral envelopes, which impart a narrow species tropism, we found that HERV-K ENV mediates broad tropism encompassing cells from multiple mammalian and nonmammalian species. We conclude that HERV-K ENV dictates an evolutionarily conserved entry pathway and that the restriction of HERV-K to primate genomes reflects downstream stages of the viral replication cycle. Approximately 8% of the human genome is of retroviral origin. While many of those viral genomes have become inactivated, some copies of the most recently endogenized human retrovirus, HERV-K, can encode individual functional proteins. Here, we characterize the envelope protein (ENV) of the virus to define how it mediates infection of cells. We demonstrate that HERV-K ENV undergoes a proteolytic processing step and triggers membrane fusion in response to acidic pH--a strategy

[Effects of acupuncture on circadian rhythm of blood pressure in patients with essential hypertension].

Science.gov (United States)

Lei, Yun; Jin, Jiu; Ban, Haipeng; Du, Yuzheng

2017-11-12

To observe the effects of acupuncture combined with medication on circadian rhythm of blood pressure in patients with essential hypertension. Sixty-four patients of essential hypertension were randomly divided into an observation group and a control group, 32 cases in each group. All the patients maintained original treatment (taking antihypertensive medication); the patients in the observation group were treated with acupuncture method of " Huoxue Sanfeng , Shugan Jianpi ", once a day, five times per week, for totally 6 weeks (30 times). The circadian rhythm of blood pressure and related dynamic parameters were observed before and after treatment in the two groups. (1) The differences of daytime average systolic blood pressure (dASBP), daytime average diastolic blood pressure (dADBP), nighttime average systolic blood pressure (nASBP) and circadian rhythm of systolic blood pressure before and after treatment were significant in the observation group (all P circadian rhythm of blood pressure and related dynamic parameters before and after treatment were insignificant in the control group (all P >0.05). The nASBP and circadian rhythm of systolic blood pressure in the observation group were significantly different from those in the control group (all P circadian rhythm of blood pressure in the observation group was higher than that in the control group ( P circadian rhythm of blood pressure and related dynamic parameters in patients with essential hypertension.

Endogenous pyrogen-like substance produced by reptiles.

Science.gov (United States)

Bernheim, H A; Kluger, M J

1977-06-01

1. Injection of lizards (Dipsosaurus dorsalis) with rabbit endogenous pyrogen led to a fever. Injections with denatured endogenous pyrogen did not affect body temperature. 2. Injection of lizards with lizard endogenous pyrogen led to a fever of short duration, while injection of denatured lizard endogenous pyrogen produced no change in body temperature. 3. These data support the hypothesis that the febrile mechanism observed in the higher vertebrates has its origins in some primitive vertebrate.

Rhythm Deficits in "Tone Deafness"

Science.gov (United States)

Foxton, Jessica M.; Nandy, Rachel K.; Griffiths, Timothy D.

2006-01-01

It is commonly observed that "tone deaf" individuals are unable to hear the beat of a tune, yet deficits on simple timing tests have not been found. In this study, we investigated rhythm processing in nine individuals with congenital amusia ("tone deafness") and nine controls. Participants were presented with pairs of 5-note sequences, and were…

Circadian rhythm resynchronization improved isoflurane-induced cognitive dysfunction in aged mice.

Science.gov (United States)

Song, Jia; Chu, Shuaishuai; Cui, Yin; Qian, Yue; Li, Xiuxiu; Xu, Fangxia; Shao, Xueming; Ma, Zhengliang; Xia, Tianjiao; Gu, Xiaoping

2018-04-13

Postoperative cognitive dysfunction (POCD) is a common clinical phenomenon characterized by cognitive deficits in patients after anesthesia and surgery. Advanced age is a significant independent risk factor for POCD. We previously reported that in young mice, sleep-wake rhythm is involved in the isoflurane-induced memory impairment. In present study, we sought to determine whether advanced age increased the risk of POCD through aggravated and prolonged post-anesthetic circadian disruption in the elderly. We constructed POCD model by submitting the mice to 5-h 1.3% isoflurane anesthesia from Zeitgeber Time (ZT) 14 to ZT19. Under novel object recognition assay (NOR) and Morris water maze (MWM) test, We found 5-h isoflurane anesthesia impaired the cognition of young mice for early 3 days after anesthesia but damaged the aged for at least 1 week. With Mini-Mitter continuously monitoring, a 3.22 ± 0.75 h gross motor activity acrophase delay was manifested in young mice on D1, while in the aged mice, the gross motor activity phase shift lasted for 3 days, consistent with the body temperature rhythm trends of change. Melatonin has been considered as an effective remedy for circadian rhythm shift. In aged mice, melatonin was pretreated intragastrically at the dose of 10 mg/kg daily for 7 consecutive days before anesthesia. We found that melatonin prevented isoflurane-induced cognitive impairments by restoring the locomotor activity and temperature circadian rhythm via clock gene resynchronization. Overall, these results indicated that Long-term isoflurane anesthesia induced more aggravated and prolonged memory deficits and circadian rhythms disruption in aged mice. Melatonin could prevent isoflurane-induced cognitive impairments by circadian rhythm resynchronization. Copyright © 2018. Published by Elsevier Inc.

Stochastic Alternating Dynamics for Synchronous EAD-Like Beating Rhythms in Cultured Cardiac Myocytes

Institute of Scientific and Technical Information of China (English)

ZHANG Ning; ZHANG Hui-Min; LIU Zhi-Qiang; DING Xue-Li; YANG Ming-Hao; GU Hua-Guang; REN Wei

2009-01-01

Dissolved cardiac myocytes can couple together and generate synchronous beatings in culture. We observed a synchronized early after-depolarization(EAD)-like rhythm in cultured cardiac myocytes and reproduced the experimental observation in a network mathematical model whose dynamics are close to a Hopf bifurcation. The mechanism for this EAD-like rhythm is attributed to noised-induced stochastic alternatings between the focus and the limit cycle. These results provide novel understandings for pathological heart rhythms like the early immature beatings.

Indirect bright light improves circadian rest-activity rhythm disturbances in demented patients

NARCIS (Netherlands)

van Someren, E. J.; Kessler, A.; Mirmiran, M.; Swaab, D. F.

1997-01-01

Light is known to be an important modulator of circadian rhythms. We tested the hypothesis than an enduring increase in the daytime environmental illumination level improves rest-activity rhythm disturbances in demented patients. Actigraphy was performed before, during, and after 4 weeks of

Two Coupled Oscillators : Simulations of the Circadian Pacemaker in Mammalian Activity Rhythms

NARCIS (Netherlands)

Daan, Serge; Berde, Charles

1978-01-01

In the activity rhythms of captive small mammals a variety of features, most notably “splitting”, sugges that two coupled oscillators may constitute the pacemaker system which underlies the rhythms. A proposed phenomenological model is developed and expanded here using an explicit quantitative

Circadian activity rhythms during the last days of Nothobranchius rachovii's life: a descriptive model of circadian system breakdown.

Science.gov (United States)

Lucas-Sánchez, Alejandro; Martínez-Nicolás, Antonio; Madrid, Juan Antonio; Almaida-Pagán, Pedro Francisco; Mendiola, Pilar; de Costa, Jorge

2015-04-01

Several studies have been performed to identify age-related changes in the circadian system (CS) but the impairment of the CS and its chronodisruption at the end of an organism life have not been studied in depth. Aging commonly affects the input pathways into the biological clock or restraints their processing, therefore simplifying the system output, the overt rhythms. The purpose of this work was to do a complete characterization of changes that occurs in the CS in the last stage of a vertebrate organism life and to develop tools able to detect in which moment of the last days of life is the animal, using an overt rhythm, the rest-activity rhythm (RAR). For that, a fish species proposed as model for aging studies, Nothobranchius rachovii, has been used. A progressive and sequential CS breakdown has been described for the last 22 d of life of N. rachovii (∼7% of total life), suffering a general RAR impairment mainly reflected by changes in phase regularity, complexity, amplitude and the ability to stay synchronized to the LD cycle. Also, an equation of days remaining of life, based on the RAR description, has been calculated and proposed as a tool to identify close-to-death individuals which could be subjected to an adequate restoring treatment to enhance the CS function and improve their well-being.

Circadian Rhythm of Ambient Noise Off the Southeast Coast of India

Science.gov (United States)

Kannan, R.; Latha, G.; Prashanthi Devi, M.

An ambient noise system consisting of a vertical linear hydrophone array was deployed in the shallow waters off Chennai, southeast coast of India from 1 August to 16 September 2013 to record ambient ocean noise of frequencies up to 10kHz. Biological sounds, which are broadband, short duration signals resulting from Terapon theraps, a native species, are a prominent feature of the ocean soundscape. Terapon activity peaks at 8pm and 11pm, and its presence is not observed after 12 midnight in both the months. In the other period, the ambient noise fluctuation is due to wind and vessel traffic. Hence, the present study focuses on the description of the ambient noise fluctuation over two 12h periods, i.e., 12 midnight-12 noon considered as period I, and 12 noon-12 midnight as period II in order to show the circadian rhythm of ambient noise. In this study area, Terapon vocalization reached 25dB above the ambient noise level and it dominates the short-term spectra records in the 0.4-4kHz range. All Terapon signals had daily patterns of sound production with highest levels of activity after dusk during the study period. The result shows that the circadian rhythm of ambient noise is mainly of biological sound generated by Terapon and it is reported first time in the shallow waters off the southeast coast of India.

Cycling of clock genes entrained to the solar rhythm enables plants to tell time: data from Arabidopsis.

Science.gov (United States)

Yeang, Hoong-Yeet

2015-07-01

An endogenous rhythm synchronized to dawn cannot time photosynthesis-linked genes to peak consistently at noon since the interval between sunrise and noon changes seasonally. In this study, a solar clock model that circumvents this limitation is proposed using two daily timing references synchronized to noon and midnight. Other rhythmic genes that are not directly linked to photosynthesis, and which peak at other times, also find an adaptive advantage in entrainment to the solar rhythm. Fourteen datasets extracted from three published papers were used in a meta-analysis to examine the cyclic behaviour of the Arabidopsis thaliana photosynthesis-related gene CAB2 and the clock oscillator genes TOC1 and LHY in T cycles and N-H cycles. Changes in the rhythms of CAB2, TOC1 and LHY in plants subjected to non-24-h light:dark cycles matched the hypothesized changes in their behaviour as predicted by the solar clock model, thus validating it. The analysis further showed that TOC1 expression peaked ∼5·5 h after mid-day, CAB2 peaked close to noon, while LHY peaked ∼7·5 h after midnight, regardless of the cycle period, the photoperiod or the light:dark period ratio. The solar clock model correctly predicted the zeitgeber timing of these genes under 11 different lighting regimes comprising combinations of seven light periods, nine dark periods, four cycle periods and four light:dark period ratios. In short cycles that terminated before LHY could be expressed, the solar clock correctly predicted zeitgeber timing of its expression in the following cycle. Regulation of gene phases by the solar clock enables the plant to tell the time, by which means a large number of genes are regulated. This facilitates the initiation of gene expression even before the arrival of sunrise, sunset or noon, thus allowing the plant to 'anticipate' dawn, dusk or mid-day respectively, independently of the photoperiod. © The Author 2015. Published by Oxford University Press on behalf of the

Shared Components of Rhythm Generation for Locomotion and Scratching Exist Prior to Motoneurons

Directory of Open Access Journals (Sweden)

Zhao-Zhe Hao

2017-08-01

Full Text Available Does the spinal cord use a single network to generate locomotor and scratching rhythms or two separate networks? Previous research showed that simultaneous swim and scratch stimulation (“dual stimulation” in immobilized, spinal turtles evokes a single rhythm in hindlimb motor nerves with a frequency often greater than during swim stimulation alone or scratch stimulation alone. This suggests that the signals that trigger swimming and scratching converge and are integrated within the spinal cord. However, these results could not determine whether the integration occurs in motoneurons themselves or earlier, in spinal interneurons. Here, we recorded intracellularly from hindlimb motoneurons during dual stimulation. Motoneuron membrane potentials displayed regular oscillations at a higher frequency during dual stimulation than during swim or scratch stimulation alone. In contrast, arithmetic addition of the oscillations during swimming alone and scratching alone with various delays always generated irregular oscillations. Also, the standard deviation of the phase-normalized membrane potential during dual stimulation was similar to those during swimming or scratching alone. In contrast, the standard deviation was greater when pooling cycles of swimming alone and scratching alone for two of the three forms of scratching. This shows that dual stimulation generates a single rhythm prior to motoneurons. Thus, either swimming and scratching largely share a rhythm generator or the two rhythms are integrated into one rhythm by strong interactions among interneurons.

Circadian rhythm in QT interval is preserved in mice deficient of potassium channel interacting protein 2

DEFF Research Database (Denmark)

Gottlieb, Lisa A; Lubberding, Anniek; Larsen, Anders Peter

2017-01-01

Potassium Channel Interacting Protein 2 (KChIP2) is suggested to be responsible for the circadian rhythm in repolarization duration, ventricular arrhythmias, and sudden cardiac death. We investigated the hypothesis that there is no circadian rhythm in QT interval in the absence of KChIP2. Implanted...... cardiac deaths were observed. We find similar diurnal (light:dark) and circadian (darkness) rhythms of RR intervals in WT and KChIP2(-/-) mice. Circadian rhythms in QT100 intervals are present in both groups, but at physiological small amplitudes: 1.6 ± 0.2 and 1.0 ± 0.3 ms in WT and KChIP2......(-/-), respectively (p = 0.15). A diurnal rhythm in QT100 intervals was only found in WT mice. QTmean-RR intervals display clear diurnal and circadian rhythms in both WT and KChIP2(-/-). The amplitude of the circadian rhythm in QTmean-RR is 4.0 ± 0.3 and 3.1 ± 0.5 ms in WT and KChIP2(-/-), respectively (p = 0...

Egg-laying rhythm in Drosophila melanogaster

Indian Academy of Sciences (India)

2008-12-31

Dec 31, 2008 ... production of oocytes to egg-laying on selected sites (Alle- mand 1976b; Yang et al. .... (vii) Is the egg-laying rhythm regulated by hormones? .... were shown to be induced by factors synthesized in the re- productive tract of the ...

Tests of the disrupted behavioral rhythms hypothesis for accelerated summer weight gain

Science.gov (United States)

The school-summer paradigm offers an opportunity to explore school-summer differences in children's behavioral rhythms and their association with seasonal changes in BMI. In the absence of the environmental demands and cues associated with the school year, children's behavioral rhythms (e.g., sleep...

Basal ganglia and cortical networks for sequential ordering and rhythm of complex movements

Directory of Open Access Journals (Sweden)

Jeffery G. Bednark

2015-07-01

Full Text Available Voluntary actions require the concurrent engagement and coordinated control of complex temporal (e.g. rhythm and ordinal motor processes. Using high-resolution functional magnetic resonance imaging (fMRI and multi-voxel pattern analysis (MVPA, we sought to determine the degree to which these complex motor processes are dissociable in basal ganglia and cortical networks. We employed three different finger-tapping tasks that differed in the demand on the sequential temporal rhythm or sequential ordering of submovements. Our results demonstrate that sequential rhythm and sequential order tasks were partially dissociable based on activation differences. The sequential rhythm task activated a widespread network centered around the SMA and basal-ganglia regions including the dorsomedial putamen and caudate nucleus, while the sequential order task preferentially activated a fronto-parietal network. There was also extensive overlap between sequential rhythm and sequential order tasks, with both tasks commonly activating bilateral premotor, supplementary motor, and superior/inferior parietal cortical regions, as well as regions of the caudate/putamen of the basal ganglia and the ventro-lateral thalamus. Importantly, within the cortical regions that were active for both complex movements, MVPA could accurately classify different patterns of activation for the sequential rhythm and sequential order tasks. In the basal ganglia, however, overlapping activation for the sequential rhythm and sequential order tasks, which was found in classic motor circuits of the putamen and ventro-lateral thalamus, could not be accurately differentiated by MVPA. Overall, our results highlight the convergent architecture of the motor system, where complex motor information that is spatially distributed in the cortex converges into a more compact representation in the basal ganglia.

Development of Salivary Cortisol Circadian Rhythm and Reference Intervals in Full-Term Infants.

Science.gov (United States)

Ivars, Katrin; Nelson, Nina; Theodorsson, Annette; Theodorsson, Elvar; Ström, Jakob O; Mörelius, Evalotte

2015-01-01

Cortisol concentrations in plasma display a circadian rhythm in adults and children older than one year. Earlier studies report divergent results regarding when cortisol circadian rhythm is established. The present study aims to investigate at what age infants develop a circadian rhythm, as well as the possible influences of behavioral regularity and daily life trauma on when the rhythm is established. Furthermore, we determine age-related reference intervals for cortisol concentrations in saliva during the first year of life. 130 healthy full-term infants were included in a prospective, longitudinal study with saliva sampling on two consecutive days, in the morning (07:30-09:30), noon (10:00-12:00) and evening (19:30-21:30), each month from birth until the infant was twelve months old. Information about development of behavioral regularity and potential exposure to trauma was obtained from the parents through the Baby Behavior Questionnaire and the Life Incidence of Traumatic Events checklist. A significant group-level circadian rhythm of salivary cortisol secretion was established at one month, and remained throughout the first year of life, although there was considerable individual variability. No correlation was found between development of cortisol circadian rhythm and the results from either the Baby Behavior Questionnaire or the Life Incidence of Traumatic Events checklist. The study presents salivary cortisol reference intervals for infants during the first twelve months of life. Cortisol circadian rhythm in infants is already established by one month of age, earlier than previous studies have shown. The current study also provides first year age-related reference intervals for salivary cortisol levels in healthy, full-term infants.

Period concatenation underlies interactions between gamma and beta rhythms in neocortex

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Anita K Roopun

2008-04-01

Full Text Available The neocortex generates rhythmic electrical activity over a frequency range covering many decades. Specific cognitive and motor states are associated with oscillations in discrete frequency bands within this range, but it is not known whether interactions and transitions between distinct frequencies are of functional importance. When coexpressed rhythms have frequencies that differ by a factor of two or more interactions can be seen in terms of phase synchronization. Larger frequency differences can result in interactions in the form of nesting of faster frequencies within slower ones by a process of amplitude modulation. It is not known how coexpressed rhythms, whose frequencies differ by less than a factor of two may interact. Here we show that two frequencies (gamma – 40 Hz and beta2 – 25 Hz, coexpressed in superficial and deep cortical laminae with low temporal interaction, can combine to generate a third frequency (beta1 – 15 Hz showing strong temporal interaction. The process occurs via period concatenation, with basic rhythm-generating microcircuits underlying gamma and beta2 rhythms forming the building blocks of the beta1 rhythm by a process of addition. The mean ratio of adjacent frequency components was a constant – approximately the golden mean – which served to both minimize temporal interactions, and permit multiple transitions, between frequencies. The resulting temporal landscape may provide a framework for multiplexing – parallel information processing on multiple temporal scales.

Mapping absolute tissue endogenous fluorophore concentrations with chemometric wide-field fluorescence microscopy

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Xu, Zhang; Reilley, Michael; Li, Run; Xu, Min

2017-06-01

We report chemometric wide-field fluorescence microscopy for imaging the spatial distribution and concentration of endogenous fluorophores in thin tissue sections. Nonnegative factorization aided by spatial diversity is used to learn both the spectral signature and the spatial distribution of endogenous fluorophores from microscopic fluorescence color images obtained under broadband excitation and detection. The absolute concentration map of individual fluorophores is derived by comparing the fluorescence from "pure" fluorophores under the identical imaging condition following the identification of the fluorescence species by its spectral signature. This method is then demonstrated by characterizing the concentration map of endogenous fluorophores (including tryptophan, elastin, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide) for lung tissue specimens. The absolute concentrations of these fluorophores are all found to decrease significantly from normal, perilesional, to cancerous (squamous cell carcinoma) tissue. Discriminating tissue types using the absolute fluorophore concentration is found to be significantly more accurate than that achievable with the relative fluorescence strength. Quantification of fluorophores in terms of the absolute concentration map is also advantageous in eliminating the uncertainties due to system responses or measurement details, yielding more biologically relevant data, and simplifying the assessment of competing imaging approaches.

A circadian rhythm orchestrated by histone deacetylase 3 controls hepatic lipid metabolism

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Feng, Dan; Liu, Tao; Sun, Zheng

2011-01-01

Disruption of the circadian clock exacerbates metabolic diseases, including obesity and diabetes. We show that histone deacetylase 3 (HDAC3) recruitment to the genome displays a circadian rhythm in mouse liver. Histone acetylation is inversely related to HDAC3 binding, and this rhythm is lost whe...

The role of stress and accent in the perception of speech rhythm

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Grover, C.N.; Terken, J.M.B.

1995-01-01

Modelling rhythmic characteristics of speech is expected to contribute to the acceptability of synthetic speech. However, before rules for the control of speech rhythm in synthetic speech can be developed, we need to know which properties of speech give rise to the perception of speech rhythm. An

Molecular genetic characterization of the RD-114 gene family of endogenous feline retroviral sequences.

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Reeves, R H; O'Brien, S J

1984-01-01

RD-114 is a replication-competent, xenotropic retrovirus which is homologous to a family of moderately repetitive DNA sequences present at ca. 20 copies in the normal cellular genome of domestic cats. To examine the extent and character of genomic divergence of the RD-114 gene family as well as to assess their positional association within the cat genome, we have prepared a series of molecular clones of endogenous RD-114 DNA segments from a genomic library of cat cellular DNA. Their restriction endonuclease maps were compared with each other as well as to that of the prototype-inducible RD-114 which was molecularly cloned from a chronically infected human cell line. The endogenous sequences analyzed were similar to each other in that they were colinear with RD-114 proviral DNA, were bounded by long terminal redundancies, and conserved many restriction sites in the gag and pol regions. However, the env regions of many of the sequences examined were substantially deleted. Several of the endogenous RD-114 genomes contained a novel envelope sequence which was unrelated to the env gene of the prototype RD-114 env gene but which, like RD-114 and endogenous feline leukemia virus provirus, was found only in species of the genus Felis, and not in other closely related Felidae genera. The endogenous RD-114 sequences each had a distinct cellular flank which indicates that these sequences are not tandem but dispersed nonspecifically throughout the genome. Southern analysis of cat cellular DNA confirmed the conclusions about conserved restriction sites in endogenous sequences and indicated that a single locus may be responsible for the production of the major inducible form of RD-114. Images PMID:6090693

Top-down beta rhythms support selective attention via interlaminar interaction: a model.

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Jung H Lee

Full Text Available Cortical rhythms have been thought to play crucial roles in our cognitive abilities. Rhythmic activity in the beta frequency band, around 20 Hz, has been reported in recent studies that focused on neural correlates of attention, indicating that top-down beta rhythms, generated in higher cognitive areas and delivered to earlier sensory areas, can support attentional gain modulation. To elucidate functional roles of beta rhythms and underlying mechanisms, we built a computational model of sensory cortical areas. Our simulation results show that top-down beta rhythms can activate ascending synaptic projections from L5 to L4 and L2/3, responsible for biased competition in superficial layers. In the simulation, slow-inhibitory interneurons are shown to resonate to the 20 Hz input and modulate the activity in superficial layers in an attention-related manner. The predicted critical roles of these cells in attentional gain provide a potential mechanism by which cholinergic drive can support selective attention.

Computational and Statistical Analyses of Insertional Polymorphic Endogenous Retroviruses in a Non-Model Organism

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Le Bao

2014-11-01

Full Text Available Endogenous retroviruses (ERVs are a class of transposable elements found in all vertebrate genomes that contribute substantially to genomic functional and structural diversity. A host species acquires an ERV when an exogenous retrovirus infects a germ cell of an individual and becomes part of the genome inherited by viable progeny. ERVs that colonized ancestral lineages are fixed in contemporary species. However, in some extant species, ERV colonization is ongoing, which results in variation in ERV frequency in the population. To study the consequences of ERV colonization of a host genome, methods are needed to assign each ERV to a location in a species’ genome and determine which individuals have acquired each ERV by descent. Because well annotated reference genomes are not widely available for all species, de novo clustering approaches provide an alternative to reference mapping that are insensitive to differences between query and reference and that are amenable to mobile element studies in both model and non-model organisms. However, there is substantial uncertainty in both identifying ERV genomic position and assigning each unique ERV integration site to individuals in a population. We present an analysis suitable for detecting ERV integration sites in species without the need for a reference genome. Our approach is based on improved de novo clustering methods and statistical models that take the uncertainty of assignment into account and yield a probability matrix of shared ERV integration sites among individuals. We demonstrate that polymorphic integrations of a recently identified endogenous retrovirus in deer reflect contemporary relationships among individuals and populations.

Circadian rhythms and obesity in mammals.

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Froy, Oren

2012-01-01

Obesity has become a serious public health problem and a major risk factor for the development of illnesses, such as insulin resistance and hypertension. Attempts to understand the causes of obesity and develop new therapeutic strategies have mostly focused on caloric intake and energy expenditure. Recent studies have shown that the circadian clock controls energy homeostasis by regulating the circadian expression and/or activity of enzymes, hormones, and transport systems involved in metabolism. Moreover, disruption of circadian rhythms leads to obesity and metabolic disorders. Therefore, it is plausible that resetting of the circadian clock can be used as a new approach to attenuate obesity. Feeding regimens, such as restricted feeding (RF), calorie restriction (CR), and intermittent fasting (IF), provide a time cue and reset the circadian clock and lead to better health. In contrast, high-fat (HF) diet leads to disrupted circadian expression of metabolic factors and obesity. This paper focuses on circadian rhythms and their link to obesity.

Neural Correlates of Phrase Rhythm: An EEG Study of Bipartite vs. Rondo Sonata Form

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Antonio Fernández-Caballero

2017-04-01

Full Text Available This paper introduces the neural correlates of phrase rhythm. In short, phrase rhythm is the rhythmic aspect of phrase construction and the relationships between phrases. For the sake of establishing the neural correlates, a musical experiment has been designed to induce music-evoked stimuli related to phrase rhythm. Brain activity is monitored through electroencephalography (EEG by using a brain–computer interface. The power spectral value of each EEG channel is estimated to obtain how power variance distributes as a function of frequency. Our experiment shows statistical differences in theta and alpha bands in the phrase rhythm variations of two classical sonatas, one in bipartite form and the other in rondo form.

Therapeutic strategies for circadian rhythm and sleep disturbances in Huntington disease.

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van Wamelen, Daniel J; Roos, Raymund Ac; Aziz, Nasir A

2015-12-01

Aside from the well-known motor, cognitive and psychiatric signs and symptoms, Huntington disease (HD) is also frequently complicated by circadian rhythm and sleep disturbances. Despite the observation that these disturbances often precede motor onset and have a high prevalence, no studies are available in HD patients which assess potential treatments. In this review, we will briefly outline the nature of circadian rhythm and sleep disturbances in HD and subsequently focus on potential treatments based on findings in other neurodegenerative diseases with similarities to HD, such as Parkinson and Alzheimer disease. The most promising treatment options to date for circadian rhythm and sleep disruption in HD include melatonin (agonists) and bright light therapy, although further corroboration in clinical trials is warranted.

Alterations in the circadian rhythm of salivary melatonin begin during middle-age

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Zhou, Jiang-Ning; Liu, Rong-Yu; van Heerikhuize, Joop; Hofman, Michel A.; Swaab, Dick F.

2003-01-01

To investigate whether free melatonin may be better suited to reveal age-related changes, we studied the circadian rhythm alterations in saliva melatonin levels during aging. Special attention was paid to the question as to how the free melatonin rhythms change in aging and when such changes take

Evidence of circadian rhythm, oxygen regulation capacity, metabolic repeatability and positive correlations between forced and spontaneous maximal metabolic rates in lake sturgeon Acipenser fulvescens.

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Jon C Svendsen

Full Text Available Animal metabolic rate is variable and may be affected by endogenous and exogenous factors, but such relationships remain poorly understood in many primitive fishes, including members of the family Acipenseridae (sturgeons. Using juvenile lake sturgeon (Acipenser fulvescens, the objective of this study was to test four hypotheses: 1 A. fulvescens exhibits a circadian rhythm influencing metabolic rate and behaviour; 2 A. fulvescens has the capacity to regulate metabolic rate when exposed to environmental hypoxia; 3 measurements of forced maximum metabolic rate (MMR(F are repeatable in individual fish; and 4 MMR(F correlates positively with spontaneous maximum metabolic rate (MMR(S. Metabolic rates were measured using intermittent flow respirometry, and a standard chase protocol was employed to elicit MMR(F. Trials lasting 24 h were used to measure standard metabolic rate (SMR and MMR(S. Repeatability and correlations between MMR(F and MMR(S were analyzed using residual body mass corrected values. Results revealed that A. fulvescens exhibit a circadian rhythm in metabolic rate, with metabolism peaking at dawn. SMR was unaffected by hypoxia (30% air saturation (O(2sat, demonstrating oxygen regulation. In contrast, MMR(F was affected by hypoxia and decreased across the range from 100% O(2sat to 70% O(2sat. MMR(F was repeatable in individual fish, and MMR(F correlated positively with MMR(S, but the relationships between MMR(F and MMR(S were only revealed in fish exposed to hypoxia or 24 h constant light (i.e. environmental stressor. Our study provides evidence that the physiology of A. fulvescens is influenced by a circadian rhythm and suggests that A. fulvescens is an oxygen regulator, like most teleost fish. Finally, metabolic repeatability and positive correlations between MMR(F and MMR(S support the conjecture that MMR(F represents a measure of organism performance that could be a target of natural selection.

Variation in nocturnality and circadian activity rhythms between photoresponsive F344 and nonphotoresponsive Sprague Dawley rats

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Johnson Cynthia E

2008-09-01

Full Text Available Abstract Background Variation in circadian rhythms and nocturnality may, hypothetically, be related to or independent of genetic variation in photoperiodic mediation of seasonal changes in physiology and behavior. We hypothesized that strain variation in photoperiodism between photoperiodic F344 rats and nonphotoperiodic Harlan Sprague Dawley (HSD rats might be caused by underlying variation in clock function. We predicted that HSD rats would have more activity during the day or subjective day, longer free-running rhythms, poor entrainment to short day length, and shorter duration of activity, traits that have been associated with nonphotoperiodism in other laboratory rodent species, relative to F344 rats. An alternative hypothesis, that differences are due to variation in melatonin secretion or responses to melatonin, predicts either no such differences or inconsistent combinations of differences. Methods We tested these predictions by examining activity rhythms of young male F344 and HSD rats given access to running wheels in constant dark (DD, short day length (L8:D16; SD, and long day length (L16:D8; LD. We compared nocturnality (the proportion of activity during night or subjective night, duration of activity (alpha, activity onset and offset, phase angle of entrainment, and free running rhythms (tau of F344 and HSD rats. Results HSD rats had significantly greater activity during the day, were sometimes arrhythmic in DD, and had significantly longer tau than F344 rats, consistent with predictions. However, HSD rats had significantly longer alpha than F344 rats and both strains entrained to SD, inconsistent with predictions. Conclusion The ability of HSD rats to entrain to SD, combined with longer alpha than F344 rats, suggests that the circadian system of HSD rats responds correctly to SD. These data offer best support for the alternative hypothesis, that differences in photoresponsiveness between F344 and HSD rats are caused by non

Demonstration of a day-night rhythm in human skeletal muscle oxidative capacity.

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van Moorsel, Dirk; Hansen, Jan; Havekes, Bas; Scheer, Frank A J L; Jörgensen, Johanna A; Hoeks, Joris; Schrauwen-Hinderling, Vera B; Duez, Helene; Lefebvre, Philippe; Schaper, Nicolaas C; Hesselink, Matthijs K C; Staels, Bart; Schrauwen, Patrick

2016-08-01

A disturbed day-night rhythm is associated with metabolic perturbations that can lead to obesity and type 2 diabetes mellitus (T2DM). In skeletal muscle, a reduced oxidative capacity is also associated with the development of T2DM. However, whether oxidative capacity in skeletal muscle displays a day-night rhythm in humans has so far not been investigated. Lean, healthy subjects were enrolled in a standardized living protocol with regular meals, physical activity and sleep to reflect our everyday lifestyle. Mitochondrial oxidative capacity was examined in skeletal muscle biopsies taken at five time points within a 24-hour period. Core-body temperature was lower during the early night, confirming a normal day-night rhythm. Skeletal muscle oxidative capacity demonstrated a robust day-night rhythm, with a significant time effect in ADP-stimulated respiration (state 3 MO, state 3 MOG and state 3 MOGS, p < 0.05). Respiration was lowest at 1 PM and highest at 11 PM (state 3 MOGS: 80.6 ± 4.0 vs. 95.8 ± 4.7 pmol/mg/s). Interestingly, the fluctuation in mitochondrial function was also observed in whole-body energy expenditure, with peak energy expenditure at 11 PM and lowest energy expenditure at 4 AM (p < 0.001). In addition, we demonstrate rhythmicity in mRNA expression of molecular clock genes in human skeletal muscle. Our results suggest that the biological clock drives robust rhythms in human skeletal muscle oxidative metabolism. It is tempting to speculate that disruption of these rhythms contribute to the deterioration of metabolic health associated with circadian misalignment.

Melatonin Entrains PER2::LUC Bioluminescence Circadian Rhythm in the Mouse Cornea

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Baba, Kenkichi; Davidson, Alec J.; Tosini, Gianluca

2015-01-01

Purpose Previous studies have reported the presence of a circadian rhythm in PERIOD2::LUCIFERASE (PER2::LUC) bioluminescence in mouse photoreceptors, retina, RPE, and cornea. Melatonin (MLT) modulates many physiological functions in the eye and it is believed to be one of the key circadian signals within the eye. The aim of the present study was to investigate the regulation of the PER2::LUC circadian rhythm in mouse cornea and to determine the role played by MLT. Methods Corneas were obtained from PER2::LUC mice and cultured to measure bioluminescence rhythmicity in isolated tissue using a Lumicycle or CCD camera. To determine the time-dependent resetting of the corneal circadian clocks in response to MLT or IIK7 (a melatonin type 2 receptor, MT2, agonist) was added to the cultured corneas at different times of the day. We also defined the location of the MT2 receptor within different corneal layers using immunohistochemistry. Results A long-lasting bioluminescence rhythm was recorded from cultured PER2::LUC cornea and PER2::LUC signal was localized to the corneal epithelium and endothelium. MLT administration in the early night delayed the cornea rhythm, whereas administration of MLT at late night to early morning advanced the cornea rhythm. Treatment with IIK7 mimicked the MLT phase-shifting effect. Consistent with these results, MT2 immunoreactivity was localized to the corneal epithelium and endothelium. Conclusions Our work demonstrates that MLT entrains the PER2::LUC bioluminescence rhythm in the cornea. Our data indicate that the cornea may represent a model to study the molecular mechanisms by which MLT affects the circadian clock. PMID:26207312

Got Rhythm...For Better and for Worse. Cross-Modal Effects of Auditory Rhythm on Visual Word Recognition

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Brochard, Renaud; Tassin, Maxime; Zagar, Daniel

2013-01-01

The present research aimed to investigate whether, as previously observed with pictures, background auditory rhythm would also influence visual word recognition. In a lexical decision task, participants were presented with bisyllabic visual words, segmented into two successive groups of letters, while an irrelevant strongly metric auditory…

Alpha-Band Rhythms in Visual Task Performance: Phase-Locking by Rhythmic Sensory Stimulation

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de Graaf, Tom A.; Gross, Joachim; Paterson, Gavin; Rusch, Tessa; Sack, Alexander T.; Thut, Gregor

2013-01-01

Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8–12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles. PMID:23555873

Hydrodynamic, non-photic modulation of biorhythms in the Norway lobster, Nephrops norvegicus (L.)

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Aguzzi, J.; Puig, P.; Company, J. B.

2009-03-01

Data on biological rhythms of the Norway lobster Nephrops norvegicus (L.) are compared with new findings on inertial currents, a non-photic geophysical hydrodynamic fluctuation. Laboratory experiments on animal endogenous cardiac activity and locomotor rhythms using individuals from the middle slope (400-600 m depth) of the Mediterranean Sea revealed a consistent proportion of ultradian 18-h animals (20.6% and 12.0% of the studied cases for cardiac and locomotor tests, respectively). This characteristic, not reported in similar experiments with individuals from shallower depths (20-200 m) in the Atlantic Ocean, was initially considered meaningless from an ecological point of view. However, a close comparison with in situ oceanographic measurements over 1 year revealed a clear relationship between inertial current fluctuations and the observed 18-h behavioural and physiological rhythms. We propose a novel scenario involving potential non-photic (i.e. hydrodynamic) modulation of Nephrops biorhythms, and suggest that this may provide a paradigm for other benthic species in deep-water areas.

Current Conceptual Challenges in the Study of Rhythm Processing Deficits

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Pauline eTranchant

2015-06-01

Full Text Available Interest in the study of rhythm processing deficits (RPD is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher’s ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization.

Human endogenous retroviruses in neurologic disease.

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Christensen, Tove

2016-01-01

Endogenous retroviruses are pathogenic - in other species than the human. Disease associations for Human Endogenous RetroViruses (HERVs) are emerging, but so far an unequivocal pathogenetic cause-effect relationship has not been established. A role for HERVs has been proposed in neurological and neuropsychiatric diseases as diverse as multiple sclerosis (MS) and schizophrenia (SCZ). Particularly for MS, many aspects of the activation and involvement of specific HERV families (HERV-H/F and HERV-W/MSRV) have been reported, both for cells in the circulation and in the central nervous system. Notably envelope genes and their gene products (Envs) appear strongly associated with the disease. For SCZ, for ALS, and for HIV-associated dementia (HAD), indications are accumulating for involvement of the HERV-K family, and also HERV-H/F and/or HERV-W. Activation is reasonably a prerequisite for causality as most HERV sequences remain quiescent in non-pathological conditions, so the importance of regulatory pathways and epigenetics involved in regulating HERV activation, derepression, and also involvement of retroviral restriction factors, is emerging. HERV-directed antiretrovirals have potential as novel therapeutic paradigms in neurologic disease, particularly in MS. The possible protective or ameliorative effects of antiretroviral therapy in MS are substantiated by reports that treatment of HIV infection may be associated with a significantly decreased risk of MS. Further studies of HERVs, their role in neurologic diseases, and their potential as therapeutic targets are essential. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Nitric oxide from both exogenous and endogenous sources activates mitochondria-dependent events and induces insults to human chondrocytes.

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Wu, Gong-Jhe; Chen, Tyng-Guey; Chang, Huai-Chia; Chiu, Wen-Ta; Chang, Chia-Chen; Chen, Ruei-Ming

2007-08-15

During inflammation, overproduction of nitric oxide (NO) can damage chondrocytes. In this study, we separately evaluated the toxic effects of exogenous and endogenous NO on human chondrocytes and their possible mechanisms. Human chondrocytes were exposed to sodium nitroprusside (SNP), an NO donor, or a combination of lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) as the exogenous and endogenous sources of NO, respectively. Administration of SNP or a combination of LPS and IFN-gamma in human chondrocytes increased cellular NO levels but decreased cell viability. Exposure to exogenous or endogenous NO significantly induced apoptosis of human chondrocytes. When treated with exogenous or endogenous NO, the mitochondrial membrane potential time-dependently decreased. Exposure to exogenous or endogenous NO significantly enhanced cellular reactive oxygen species (ROS) and cytochrome c (Cyt c) levels. Administration of exogenous or endogenous NO increased caspase-3 activity and consequently induced DNA fragmentation. Suppression of caspase-3 activation by Z-DEVD-FMK decreased NO-induced DNA fragmentation and cell apoptosis. Similar to SNP, exposure of human chondrocytes to S-nitrosoglutathione (GSNO), another NO donor, caused significant increases in Cyt c levels, caspase-3 activity, and DNA fragmentation, and induced cell apoptosis. Pretreatment with N-monomethyl arginine (NMMA), an inhibitor of NO synthase, significantly decreased cellular NO levels, and lowered endogenous NO-induced alterations in cellular Cyt c amounts, caspase-3 activity, DNA fragmentation, and cell apoptosis. Results of this study show that NO from exogenous and endogenous sources can induce apoptotic insults to human chondrocytes via a mitochondria-dependent mechanism.

Effect of age, gender and exercise on salivary dehydroepiandrosterone circadian rhythm profile in human volunteers.

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Al-Turk, Walid; Al-Dujaili, Emad A S

2016-02-01

There has been a lot of effort by scientists to elucidate the multi functions of the naturally occurring hormone, dehydroepiandrosterone (DHEA). However, to plan research experiments optimally, it is important first to characterize the diurnal rhythm in healthy individuals. The aim of this research was to investigate the daily circadian rhythms of DHEA among the 2 genders, and the effect of age and exercise on salivary DHEA circadian rhythms. Volunteers (20-39 and 40-60 years) were recruited for 2 studies investigating the salivary DHEA circadian rhythm. The first study looked at the effect of gender and age on DHEA levels on 2 non-consecutive days, and the second study explored the effect of exercise on DHEA circadian rhythm in males. DHEA levels were estimated by a sensitive and specific ELISA method. The results showed a clear daily circadian rhythm in salivary DHEA in all participants groups, however the profile was flatter in the older female group. There was a significant difference between age and gender groups particularly at 8.00 h. In young males DHEA reduced from 541.1 ± 101.3 (mean ± sd) at 8.00 h to 198.9 ± 90.7 pg/mL at 18.00 h; pcircadian rhythm in salivary DHEA in all participants was observed, but the profile was flatter in the older groups. Copyright © 2016. Published by Elsevier Inc.

Fluoxetine normalizes disrupted light-induced entrainment, fragmented ultradian rhythms and altered hippocampal clock gene expression in an animal model of high trait anxiety- and depression-related behavior.

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Schaufler, Jörg; Ronovsky, Marianne; Savalli, Giorgia; Cabatic, Maureen; Sartori, Simone B; Singewald, Nicolas; Pollak, Daniela D

2016-01-01

Disturbances of circadian rhythms are a key symptom of mood and anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) - commonly used antidepressant drugs - also modulate aspects of circadian rhythmicity. However, their potential to restore circadian disturbances in depression remains to be investigated. The effects of the SSRI fluoxetine on genetically based, depression-related circadian disruptions at the behavioral and molecular level were examined using mice selectively bred for high anxiety-related and co-segregating depression-like behavior (HAB) and normal anxiety/depression behavior mice (NAB). The length of the circadian period was increased in fluoxetine-treated HAB as compared to NAB mice while the number of activity bouts and light-induced entrainment were comparable. No difference in hippocampal Cry2 expression, previously reported to be dysbalanced in untreated HAB mice, was observed, while Per2 and Per3 mRNA levels were higher in HAB mice under fluoxetine treatment. The present findings provide evidence that fluoxetine treatment normalizes disrupted circadian locomotor activity and clock gene expression in a genetic mouse model of high trait anxiety and depression. An interaction between the molecular mechanisms mediating the antidepressant response to fluoxetine and the endogenous regulation of circadian rhythms in genetically based mood and anxiety disorders is proposed.

Endogenous zinc excretion in relation to various levels of dietary zinc intake in the mink (Mustela vison)

International Nuclear Information System (INIS)

Mejborn, H.

1990-01-01

Endogenous zinc excretion was studied in adult male mink fed experimental diets for 73 d, including a collection period from d 69 to 73. Dietary zinc levels were 2.8, 26 or 121 mg/kg wet weight. In accordance with the results of a methodological study, also reported here, the animals had an intramuscular injection of 65ZnCl2 12 d before the start of the collection period. Total fecal (endogenous + unabsorbed) zinc excretion for d 69-73 in the three groups was 2.3, 20.4 and 91.0 mg. The endogenous zinc excretion was 1.3, 2.0 and 6.4 mg, corresponding to 80.8, 10.6 and 6.4% of the zinc intake. Thus, the endogenous excretion was mainly important for the zinc homeostasis at low zinc intake, whereas at high intake the homeostasis was regulated via absorption from the digestive tract. The overall conclusion of the experiment was that mink are comparable to other species (including man) in regard to mechanisms controlling zinc homeostasis

Fos expression in the suprachiasmatic nucleus in response to light stimulation in a solitary and social species of African mole-rat (family Bathyergidae).

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Oosthuizen, M K; Bennett, N C; Cooper, H M

2005-01-01

Mole-rats are strictly subterranean rodents that are rarely exposed to environmental light. They are well adapted to their environment and have reduced eyes and a severely regressed visual system. It has been shown, however, that mole-rats do exhibit endogenous circadian rhythms that can be entrained, suggesting an intact and functional circadian system. To determine whether light is the entraining agent in these animals, Fos expression in response to light pulses at different circadian times was investigated to obtain phase response curves. Light is integrated effectively in the suprachiasmatic nucleus of the Cape mole-rat (Georychus capensis), and Fos expression is gated according to the phase of the circadian clock. The Fos response in the Cape mole-rat was comparable to that of aboveground rodents. In contrast, the highveld mole-rat (Cryptomys hottentotus pretoriae) was less sensitive to light and did not show a selective Fos response according to the phase of the circadian cycle. Social species appear to be less sensitive to light than their solitary counterparts, which compares well with results from locomotor activity studies.

Gypsy endogenous retrovirus maintains potential infectivity in several species of Drosophilids

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de Frutos Rosa

2008-10-01

Full Text Available Abstract Background Sequences homologous to the gypsy retroelement from Drosophila melanogaster are widely distributed among drosophilids. The structure of gypsy includes an open reading frame resembling the retroviral gene env, which is responsible for the infectious properties of retroviruses. Results In this study we report molecular and phylogeny analysis of the complete env gene from ten species of the obscura group of the genus Drosophila and one species from the genus Scaptomyza. Conclusion The results indicate that in most cases env sequences could produce a functional Env protein and therefore maintain the infectious capability of gypsy in these species.

Circadian Rhythm Disturbances in Mood Disorders: Insights into the Role of the Suprachiasmatic Nucleus

Science.gov (United States)

2017-01-01

Circadian rhythm disturbances are a common symptom among individuals with mood disorders. The suprachiasmatic nucleus (SCN), in the ventral part of the anterior hypothalamus, orchestrates physiological and behavioral circadian rhythms. The SCN consists of self-sustaining oscillators and receives photic and nonphotic cues, which entrain the SCN to the external environment. In turn, through synaptic and hormonal mechanisms, the SCN can drive and synchronize circadian rhythms in extra-SCN brain regions and peripheral tissues. Thus, genetic or environmental perturbations of SCN rhythms could disrupt brain regions more closely related to mood regulation and cause mood disturbances. Here, we review clinical and preclinical studies that provide evidence both for and against a causal role for the SCN in mood disorders. PMID:29230328

Endogenous Fluorescence Signatures in Living Pluripotent Stem Cells Change with Loss of Potency

Science.gov (United States)

Squirrell, Jayne M.; Fong, Jimmy J.; Ariza, Carlos A.; Mael, Amber; Meyer, Kassondra; Shevde, Nirupama K.; Roopra, Avtar; Lyons, Gary E.; Kamp, Timothy J.; Eliceiri, Kevin W.; Ogle, Brenda M.

2012-01-01

The therapeutic potential of stem cells is limited by the non-uniformity of their phenotypic state. Thus it would be advantageous to noninvasively monitor stem cell status. Driven by this challenge, we employed multidimensional multiphoton microscopy to quantify changes in endogenous fluorescence occurring with pluripotent stem cell differentiation. We found that global and cellular-scale fluorescence lifetime of human embryonic stem cells (hESC) and murine embryonic stem cells (mESC) consistently decreased with differentiation. Less consistent were trends in endogenous fluorescence intensity with differentiation, suggesting intensity is more readily impacted by nuances of species and scale of analysis. What emerges is a practical and accessible approach to evaluate, and ultimately enrich, living stem cell populations based on changes in metabolism that could be exploited for both research and clinical applications. PMID:22952742

Circadian rhythms in handwriting kinematics and legibility.

Science.gov (United States)

Jasper, Isabelle; Gordijn, Marijke; Häussler, Andreas; Hermsdörfer, Joachim

2011-08-01

The aim of the present study was to analyze the circadian rhythmicity in handwriting kinematics and legibility and to compare the performance between Dutch and German writers. Two subject groups underwent a 40 h sleep deprivation protocol under Constant Routine conditions either in Groningen (10 Dutch subjects) or in Berlin (9 German subjects). Both groups wrote every 3h a test sentence of similar structure in their native language. Kinematic handwriting performance was assessed with a digitizing tablet and evaluated by writing speed, writing fluency, and script size. Writing speed (frequency of strokes and average velocity) revealed a clear circadian rhythm, with a parallel decline during night and a minimum around 3:00 h in the morning for both groups. Script size and movement fluency did not vary with time of day in neither group. Legibility of handwriting was evaluated by intra-individually ranking handwriting specimens of the 13 sessions by 10 German and 10 Dutch raters. Whereas legibility ratings of the German handwriting specimens deteriorated during night in parallel with slower writing speed, legibility of the Dutch handwriting deteriorated not until the next morning. In conclusion, the circadian rhythm of handwriting kinematics seems to be independent of script language at least among the two tested western countries. Moreover, handwriting legibility is also subject to a circadian rhythm which, however, seems to be influenced by variations in the assessment protocol. Copyright © 2010 Elsevier B.V. All rights reserved.

Circadian rhythm of temperature selection in a nocturnal lizard.

Science.gov (United States)

Refinetti, R; Susalka, S J

1997-08-01

We recorded body temperature and locomotor activity of Tokay geckos (Gekko gecko) with free access to a heat source under a 14:10 light-dark cycle and in constant darkness. Under the light-dark cycle, the lizards selected higher temperatures during the light phase, when locomotor activity was less intense. Rhythmicity in temperature selection was transiently disrupted but later resumed when the animals were placed in constant darkness. These results demonstrate the existence of a circadian rhythm of temperature selection in nocturnal ectotherms and extend previous findings of a temporal mismatch between the rhythms of locomotor activity and temperature selection in nocturnal rodents.

Clock Genes and Altered Sleep-Wake Rhythms: Their Role in the Development of Psychiatric Disorders.

Science.gov (United States)

Charrier, Annaëlle; Olliac, Bertrand; Roubertoux, Pierre; Tordjman, Sylvie

2017-04-29

In mammals, the circadian clocks network (central and peripheral oscillators) controls circadian rhythms and orchestrates the expression of a range of downstream genes, allowing the organism to anticipate and adapt to environmental changes. Beyond their role in circadian rhythms, several studies have highlighted that circadian clock genes may have a more widespread physiological effect on cognition, mood, and reward-related behaviors. Furthermore, single nucleotide polymorphisms in core circadian clock genes have been associated with psychiatric disorders (such as autism spectrum disorder, schizophrenia, anxiety disorders, major depressive disorder, bipolar disorder, and attention deficit hyperactivity disorder). However, the underlying mechanisms of these associations remain to be ascertained and the cause-effect relationships are not clearly established. The objective of this article is to clarify the role of clock genes and altered sleep-wake rhythms in the development of psychiatric disorders (sleep problems are often observed at early onset of psychiatric disorders). First, the molecular mechanisms of circadian rhythms are described. Then, the relationships between disrupted circadian rhythms, including sleep-wake rhythms, and psychiatric disorders are discussed. Further research may open interesting perspectives with promising avenues for early detection and therapeutic intervention in psychiatric disorders.

Clock Genes and Altered Sleep–Wake Rhythms: Their Role in the Development of Psychiatric Disorders

Directory of Open Access Journals (Sweden)

Annaëlle Charrier

2017-04-01

Full Text Available In mammals, the circadian clocks network (central and peripheral oscillators controls circadian rhythms and orchestrates the expression of a range of downstream genes, allowing the organism to anticipate and adapt to environmental changes. Beyond their role in circadian rhythms, several studies have highlighted that circadian clock genes may have a more widespread physiological effect on cognition, mood, and reward-related behaviors. Furthermore, single nucleotide polymorphisms in core circadian clock genes have been associated with psychiatric disorders (such as autism spectrum disorder, schizophrenia, anxiety disorders, major depressive disorder, bipolar disorder, and attention deficit hyperactivity disorder. However, the underlying mechanisms of these associations remain to be ascertained and the cause–effect relationships are not clearly established. The objective of this article is to clarify the role of clock genes and altered sleep–wake rhythms in the development of psychiatric disorders (sleep problems are often observed at early onset of psychiatric disorders. First, the molecular mechanisms of circadian rhythms are described. Then, the relationships between disrupted circadian rhythms, including sleep–wake rhythms, and psychiatric disorders are discussed. Further research may open interesting perspectives with promising avenues for early detection and therapeutic intervention in psychiatric disorders.

Serial recall of rhythms and verbal sequences: Impacts of concurrent tasks and irrelevant sound.

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Hall, Debbora; Gathercole, Susan E

2011-08-01

Rhythmic grouping enhances verbal serial recall, yet very little is known about memory for rhythmic patterns. The aim of this study was to compare the cognitive processes supporting memory for rhythmic and verbal sequences using a range of concurrent tasks and irrelevant sounds. In Experiment 1, both concurrent articulation and paced finger tapping during presentation and during a retention interval impaired rhythm recall, while letter recall was only impaired by concurrent articulation. In Experiments 2 and 3, irrelevant sound consisted of irrelevant speech or tones, changing-state or steady-state sound, and syncopated or paced sound during presentation and during a retention interval. Irrelevant speech was more damaging to rhythm and letter recall than was irrelevant tone sound, but there was no effect of changing state on rhythm recall, while letter recall accuracy was disrupted by changing-state sound. Pacing of sound did not consistently affect either rhythm or letter recall. There are similarities in the way speech and rhythms are processed that appear to extend beyond reliance on temporal coding mechanisms involved in serial-order recall.

Cancer Clocks Out for Lunch: Disruption of Circadian Rhythm and Metabolic Oscillation in Cancer.

Science.gov (United States)

Altman, Brian J

2016-01-01

Circadian rhythms are 24-h oscillations present in most eukaryotes and many prokaryotes that synchronize activity to the day-night cycle. They are an essential feature of organismal and cell physiology that coordinate many of the metabolic, biosynthetic, and signal transduction pathways studied in biology. The molecular mechanism of circadian rhythm is controlled both by signal transduction and gene transcription as well as by metabolic feedback. The role of circadian rhythm in cancer cell development and survival is still not well understood, but as will be discussed in this Review, accumulated research suggests that circadian rhythm may be altered or disrupted in many human cancers downstream of common oncogenic alterations. Thus, a complete understanding of the genetic and metabolic alterations in cancer must take potential circadian rhythm perturbations into account, as this disruption itself will influence how gene expression and metabolism are altered in the cancer cell compared to its non-transformed neighbor. It will be important to better understand these circadian changes in both normal and cancer cell physiology to potentially design treatment modalities to exploit this insight.

Silver resistance in Gram-negative bacteria: a dissection of endogenous and exogenous mechanisms.

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Randall, Christopher P; Gupta, Arya; Jackson, Nicole; Busse, David; O'Neill, Alex J

2015-04-01

To gain a more detailed understanding of endogenous (mutational) and exogenous (horizontally acquired) resistance to silver in Gram-negative pathogens, with an emphasis on clarifying the genetic bases for resistance. A suite of microbiological and molecular genetic techniques was employed to select and characterize endogenous and exogenous silver resistance in several Gram-negative species. In Escherichia coli, endogenous resistance arose after 6 days of exposure to silver, a consequence of two point mutations that were both necessary and sufficient for the phenotype. These mutations, in ompR and cusS, respectively conferred loss of the OmpC/F porins and derepression of the CusCFBA efflux transporter, both phenotypic changes previously linked to reduced intracellular accumulation of silver. Exogenous resistance involved derepression of the SilCFBA efflux transporter as a consequence of mutation in silS, but was additionally contingent on expression of the periplasmic silver-sequestration protein SilE. Silver resistance could be selected at high frequency (>10(-9)) from Enterobacteriaceae lacking OmpC/F porins or harbouring the sil operon and both endogenous and exogenous resistance were associated with modest fitness costs in vitro. Both endogenous and exogenous silver resistance are dependent on the derepressed expression of closely related efflux transporters and are therefore mechanistically similar phenotypes. The ease with which silver resistance can become selected in some bacterial pathogens in vitro suggests that there would be benefit in improved surveillance for silver-resistant isolates in the clinic, along with greater control over use of silver-containing products, in order to best preserve the clinical utility of silver. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Estimation of Circadian Body Temperature Rhythm Based on Heart Rate in Healthy, Ambulatory Subjects.

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Sim, Soo Young; Joo, Kwang Min; Kim, Han Byul; Jang, Seungjin; Kim, Beomoh; Hong, Seungbum; Kim, Sungwan; Park, Kwang Suk

2017-03-01

Core body temperature is a reliable marker for circadian rhythm. As characteristics of the circadian body temperature rhythm change during diverse health problems, such as sleep disorder and depression, body temperature monitoring is often used in clinical diagnosis and treatment. However, the use of current thermometers in circadian rhythm monitoring is impractical in daily life. As heart rate is a physiological signal relevant to thermoregulation, we investigated the feasibility of heart rate monitoring in estimating circadian body temperature rhythm. Various heart rate parameters and core body temperature were simultaneously acquired in 21 healthy, ambulatory subjects during their routine life. The performance of regression analysis and the extended Kalman filter on daily body temperature and circadian indicator (mesor, amplitude, and acrophase) estimation were evaluated. For daily body temperature estimation, mean R-R interval (RRI), mean heart rate (MHR), or normalized MHR provided a mean root mean square error of approximately 0.40 °C in both techniques. The mesor estimation regression analysis showed better performance than the extended Kalman filter. However, the extended Kalman filter, combined with RRI or MHR, provided better accuracy in terms of amplitude and acrophase estimation. We suggest that this noninvasive and convenient method for estimating the circadian body temperature rhythm could reduce discomfort during body temperature monitoring in daily life. This, in turn, could facilitate more clinical studies based on circadian body temperature rhythm.

Controlling Circadian Rhythms by Dark-Pulse Perturbations in Arabidopsis thaliana

Science.gov (United States)

Fukuda, Hirokazu; Murase, Haruhiko; Tokuda, Isao T.

2013-01-01

Plant circadian systems are composed of a large number of self-sustained cellular circadian oscillators. Although the light-dark signal in the natural environment is known to be the most powerful Zeitgeber for the entrainment of cellular oscillators, its effect is too strong to control the plant rhythm into various forms of synchrony. Here, we show that the application of pulse perturbations, i.e., short-term injections of darkness under constant light, provides a novel technique for controlling the synchronized behavior of plant rhythm in Arabidopsis thaliana. By destroying the synchronized cellular activities, circadian singularity was experimentally induced. The present technique is based upon the theory of phase oscillators, which does not require prior knowledge of the detailed dynamics of the plant system but only knowledge of its phase and amplitude responses to the pulse perturbation. Our approach can be applied to diverse problems of controlling biological rhythms in living systems. PMID:23524981

A multimodal spectral approach to characterize rhythm in natural speech.

Science.gov (United States)

Alexandrou, Anna Maria; Saarinen, Timo; Kujala, Jan; Salmelin, Riitta

2016-01-01

Human utterances demonstrate temporal patterning, also referred to as rhythm. While simple oromotor behaviors (e.g., chewing) feature a salient periodical structure, conversational speech displays a time-varying quasi-rhythmic pattern. Quantification of periodicity in speech is challenging. Unimodal spectral approaches have highlighted rhythmic aspects of speech. However, speech is a complex multimodal phenomenon that arises from the interplay of articulatory, respiratory, and vocal systems. The present study addressed the question of whether a multimodal spectral approach, in the form of coherence analysis between electromyographic (EMG) and acoustic signals, would allow one to characterize rhythm in natural speech more efficiently than a unimodal analysis. The main experimental task consisted of speech production at three speaking rates; a simple oromotor task served as control. The EMG-acoustic coherence emerged as a sensitive means of tracking speech rhythm, whereas spectral analysis of either EMG or acoustic amplitude envelope alone was less informative. Coherence metrics seem to distinguish and highlight rhythmic structure in natural speech.

Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress

Science.gov (United States)

Magdalou, Indiana; Machon, Christelle; Dardillac, Elodie; Técher, Hervé; Guitton, Jérôme; Debatisse, Michelle; Lopez, Bernard S.

2016-01-01

Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3%) rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing), and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and senescence initiation

Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress.

Directory of Open Access Journals (Sweden)

Therese Wilhelm

2016-05-01

Full Text Available Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es. Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3% rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing, and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and

Slow Replication Fork Velocity of Homologous Recombination-Defective Cells Results from Endogenous Oxidative Stress.

Science.gov (United States)

Wilhelm, Therese; Ragu, Sandrine; Magdalou, Indiana; Machon, Christelle; Dardillac, Elodie; Técher, Hervé; Guitton, Jérôme; Debatisse, Michelle; Lopez, Bernard S

2016-05-01

Replications forks are routinely hindered by different endogenous stresses. Because homologous recombination plays a pivotal role in the reactivation of arrested replication forks, defects in homologous recombination reveal the initial endogenous stress(es). Homologous recombination-defective cells consistently exhibit a spontaneously reduced replication speed, leading to mitotic extra centrosomes. Here, we identify oxidative stress as a major endogenous source of replication speed deceleration in homologous recombination-defective cells. The treatment of homologous recombination-defective cells with the antioxidant N-acetyl-cysteine or the maintenance of the cells at low O2 levels (3%) rescues both the replication fork speed, as monitored by single-molecule analysis (molecular combing), and the associated mitotic extra centrosome frequency. Reciprocally, the exposure of wild-type cells to H2O2 reduces the replication fork speed and generates mitotic extra centrosomes. Supplying deoxynucleotide precursors to H2O2-exposed cells rescued the replication speed. Remarkably, treatment with N-acetyl-cysteine strongly expanded the nucleotide pool, accounting for the replication speed rescue. Remarkably, homologous recombination-defective cells exhibit a high level of endogenous reactive oxygen species. Consistently, homologous recombination-defective cells accumulate spontaneous γH2AX or XRCC1 foci that are abolished by treatment with N-acetyl-cysteine or maintenance at 3% O2. Finally, oxidative stress stimulated homologous recombination, which is suppressed by supplying deoxynucleotide precursors. Therefore, the cellular redox status strongly impacts genome duplication and transmission. Oxidative stress should generate replication stress through different mechanisms, including DNA damage and nucleotide pool imbalance. These data highlight the intricacy of endogenous replication and oxidative stresses, which are both evoked during tumorigenesis and senescence initiation

Evaluation of circadian phenotypes utilizing fibroblasts from patients with circadian rhythm sleep disorders.

Science.gov (United States)

Hida, A; Ohsawa, Y; Kitamura, S; Nakazaki, K; Ayabe, N; Motomura, Y; Matsui, K; Kobayashi, M; Usui, A; Inoue, Y; Kusanagi, H; Kamei, Y; Mishima, K

2017-04-25

We evaluated the circadian phenotypes of patients with delayed sleep-wake phase disorder (DSWPD) and non-24-hour sleep-wake rhythm disorder (N24SWD), two different circadian rhythm sleep disorders (CRSDs) by measuring clock gene expression rhythms in fibroblast cells derived from individual patients. Bmal1-luciferase (Bmal1-luc) expression rhythms were measured in the primary fibroblast cells derived from skin biopsy samples of patients with DSWPD and N24SWD, as well as control subjects. The period length of the Bmal1-luc rhythm (in vitro period) was distributed normally and was 22.80±0.47 (mean±s.d.) h in control-derived fibroblasts. The in vitro periods in DSWPD-derived fibroblasts and N24SWD-derived fibroblasts were 22.67±0.67 h and 23.18±0.70 h, respectively. The N24SWD group showed a significantly longer in vitro period than did the control or DSWPD group. Furthermore, in vitro period was associated with response to chronotherapy in the N24SWD group. Longer in vitro periods were observed in the non-responders (mean±s.d.: 23.59±0.89 h) compared with the responders (mean±s.d.: 22.97±0.47 h) in the N24SWD group. Our results indicate that prolonged circadian periods contribute to the onset and poor treatment outcome of N24SWD. In vitro rhythm assays could be useful for predicting circadian phenotypes and clinical prognosis in patients with CRSDs.

Orchestrating intensities and rhythms

DEFF Research Database (Denmark)

Staunæs, Dorthe; Juelskjær, Malou

2016-01-01

environmentality and learning-centered governance standards has dramatic and performative effects for the production of (educational) subjectivities. This implies a shift from governing identities, categories and structures towards orchestrating affective intensities and rhythms. Finally, the article discusses...... and the making of subjects have held sway for many years; and it is also well known that schools have been some of the most regular purchasers of psychological methods, tests and classifications. Following but also elaborating upon governmentality studies, it is suggested that a current shift towards...

Limited evidence for affective and diurnal rhythm responses to dim light-at-night in male and female C57Bl/6 mice.

Science.gov (United States)

Cleary-Gaffney, Michael; Coogan, Andrew N

2018-05-15

Circadian rhythms are recurring patterns in a range of behavioural, physiological and molecular parameters that display periods of near 24 h, and are underpinned by an endogenous biological timekeeping system. Circadian clocks are increasingly recognised as being key for health. Environmental light is the key stimulus that synchronises the internal circadian system with the external time cues. There are emergent health concerns regarding increasing worldwide prevalence of electric lighting, especially man-made light-at-night, and light's impact on the circadian system may be central to these effects. A number of previous studies have demonstrated increased depression-like behaviour in various rodent experimental models exposed to dim light-at-night. In this study we set out to study the impact of dim light-at-night on circadian and affective behaviours in C57Bl/6 mice. We set out specifically to examine the impact of sex on light at night's effects, as well as the impact of housing conditions. We report minimal impact of light-at-night on circadian and affective behaviours, as measured by the tail suspension test, the forced swim test, the sucrose preference test and the elevated plus maze. Light-at-night was also not associated with an increase in body weight, but was associated with a decrease in the cell proliferation marker Ki-67 in the dentate gyrus. In summary, we conclude that experimental contextual factors, such as model species or strain, may be considerable importance in the investigation of the impact of light at night on mood-related parameters. Copyright © 2018 Elsevier Inc. All rights reserved.

The population history of endogenous retroviruses in mule deer (Odocoileus heminous)

Science.gov (United States)

Kamath, Pauline L.; Elleder, Daniel; Bao, Le; Cross, Paul C.; Powell, John H.; Poss, Mary

2013-01-01

Mobile elements are powerful agents of genomic evolution and can be exceptionally informative markers for investigating species and population-level evolutionary history. While several studies have utilized retrotransposon-based insertional polymorphisms to resolve phylogenies, few population studies exist outside of humans. Endogenous retroviruses are LTR-retrotransposons derived from retroviruses that have become stably integrated in the host genome during past infections and transmitted vertically to subsequent generations. They offer valuable insight into host-virus co-evolution and a unique perspective on host evolutionary history because they integrate into the genome at a discrete point in time. We examined the evolutionary history of a cervid endogenous gammaretrovirus (CrERVγ) in mule deer (Odocoileus hemionus). We sequenced 14 CrERV proviruses (CrERV-in1 to -in14), and examined the prevalence and distribution of 13 proviruses in 262 deer among 15 populations from Montana, Wyoming, and Utah. CrERV absence in white-tailed deer (O. virginianus), identical 5′ and 3′ long terminal repeat (LTR) sequences, insertional polymorphism, and CrERV divergence time estimates indicated that most endogenization events occurred within the last 200000 years. Population structure inferred from CrERVs (F ST = 0.008) and microsatellites (θ = 0.01) was low, but significant, with Utah, northwestern Montana, and a Helena herd being particularly differentiated. Clustering analyses indicated regional structuring, and non-contiguous clustering could often be explained by known translocations. Cluster ensemble results indicated spatial localization of viruses, specifically in deer from northeastern and western Montana. This study demonstrates the utility of endogenous retroviruses to elucidate and provide novel insight into both ERV evolutionary history and the history of contemporary host populations.

The population history of endogenous retroviruses in mule deer (Odocoileus hemionus).

Science.gov (United States)

Kamath, Pauline L; Elleder, Daniel; Bao, Le; Cross, Paul C; Powell, John H; Poss, Mary

2014-01-01

Mobile elements are powerful agents of genomic evolution and can be exceptionally informative markers for investigating species and population-level evolutionary history. While several studies have utilized retrotransposon-based insertional polymorphisms to resolve phylogenies, few population studies exist outside of humans. Endogenous retroviruses are LTR-retrotransposons derived from retroviruses that have become stably integrated in the host genome during past infections and transmitted vertically to subsequent generations. They offer valuable insight into host-virus co-evolution and a unique perspective on host evolutionary history because they integrate into the genome at a discrete point in time. We examined the evolutionary history of a cervid endogenous gammaretrovirus (CrERVγ) in mule deer (Odocoileus hemionus). We sequenced 14 CrERV proviruses (CrERV-in1 to -in14), and examined the prevalence and distribution of 13 proviruses in 262 deer among 15 populations from Montana, Wyoming, and Utah. CrERV absence in white-tailed deer (O. virginianus), identical 5' and 3' long terminal repeat (LTR) sequences, insertional polymorphism, and CrERV divergence time estimates indicated that most endogenization events occurred within the last 200000 years. Population structure inferred from CrERVs (F ST = 0.008) and microsatellites (θ = 0.01) was low, but significant, with Utah, northwestern Montana, and a Helena herd being particularly differentiated. Clustering analyses indicated regional structuring, and non-contiguous clustering could often be explained by known translocations. Cluster ensemble results indicated spatial localization of viruses, specifically in deer from northeastern and western Montana. This study demonstrates the utility of endogenous retroviruses to elucidate and provide novel insight into both ERV evolutionary history and the history of contemporary host populations.

Ciliary neurotrophic factor is an endogenous pyrogen.

Science.gov (United States)

Shapiro, L; Zhang, X X; Rupp, R G; Wolff, S M; Dinarello, C A

1993-09-15

Fever is initiated by the action of polypeptide cytokines called endogenous pyrogens, which are produced by the host during inflammation, trauma, or infection and which elevate the thermoregulatory set point in the hypothalamus. Ciliary neurotrophic factor (CNTF) supports the differentiation and survival of central and peripheral neurons. We describe the activity of CNTF as intrinsically pyrogenic in the rabbit. CNTF induced a monophasic fever which rose rapidly (within the first 12 min) following intravenous injection; CNTF fever was blocked by pretreatment with indomethacin. The fever induced by CNTF was not due to contaminating endotoxins. Increasing doses of CNTF resulted in prolongation of the fever, suggesting the subsequent induction of additional endogenous pyrogenic activity. After passive transfer of plasma obtained during CNTF-induced fever, endogenous pyrogen activity was not present in the circulation; CNTF also did not induce the endogenous pyrogens interleukin 1, tumor necrosis factor, or interleukin 6 in vitro. Nevertheless, a second endogenous pyrogen may originate within the central nervous system following the systemic injection of CNTF. Of the four endogenous pyrogens described to date (interleukin 1, tumor necrosis factor, interferon, and interleukin 6), CNTF, like interleukin 6, utilizes the cell-surface gp 130 signal-transduction apparatus.

[Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation].

Science.gov (United States)

Ben Khalfallah, A; Sanaa, I

2007-09-01

Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, ppredict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and Pe

EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

Directory of Open Access Journals (Sweden)

Karagul Osman

2017-09-01

Full Text Available Introduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material and

Clinical predictors of shockable versus non-shockable rhythms in patients with out-of-hospital cardiac arrest

DEFF Research Database (Denmark)

Granfeldt, Asger; Wissenberg, Mads; Hansen, Steen Møller

2016-01-01

Aim To identify factors associated with a non-shockable rhythm as first recorded heart rhythm. Methods Patients ≥18 years old suffering out-of-hospital cardiac arrest between 2001 and 2012 were identified in the population-based Danish Cardiac Arrest Registry. Danish administrative registries were...... used to identify chronic diseases (within 10 years) and drug prescriptions (within 180 days). A multivariable logistic regression model, including patient related and cardiac arrest related characteristics, was used to estimate odds ratios (OR) for factors associated with non-shockable rhythm. Results...... compared to patients with shockable rhythm. In the adjusted multivariable regression model, pre-existing non-cardiovascular disease and drug prescription were associated with a non-shockable rhythm e.g. chronic obstructive lung disease (OR 1.44 [95% CI: 1.32–1.58]); and the prescription for antidepressants...

Lighting, sleep and circadian rhythm: An intervention study in the intensive care unit.

Science.gov (United States)

Engwall, Marie; Fridh, Isabell; Johansson, Lotta; Bergbom, Ingegerd; Lindahl, Berit

2015-12-01

Patients in an intensive care unit (ICU) may risk disruption of their circadian rhythm. In an intervention research project a cycled lighting system was set up in an ICU room to support patients' circadian rhythm. Part I aimed to compare experiences of the lighting environment in two rooms with different lighting environments by lighting experiences questionnaire. The results indicated differences in advantage for the patients in the intervention room (n=48), in perception of daytime brightness (p=0.004). In nighttime, greater lighting variation (p=0.005) was found in the ordinary room (n=52). Part II aimed to describe experiences of lighting in the room equipped with the cycled lighting environment. Patients (n=19) were interviewed and the results were presented in categories: "A dynamic lighting environment", "Impact of lighting on patients' sleep", "The impact of lighting/lights on circadian rhythm" and "The lighting calms". Most had experiences from sleep disorders and half had nightmares/sights and circadian rhythm disruption. Nearly all were pleased with the cycled lighting environment, which together with daylight supported their circadian rhythm. In night's actual lighting levels helped patients and staff to connect which engendered feelings of calm. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Spinal Hb9::Cre-derived excitatory interneurons contribute to rhythm generation in the mouse

DEFF Research Database (Denmark)

Caldeira, Vanessa; Dougherty, Kimberly J.; Borgius, Lotta

2017-01-01

Rhythm generating neurons are thought to be ipsilaterally-projecting excitatory neurons in the thoracolumbar mammalian spinal cord. Recently, a subset of Shox2 interneurons (Shox2 non-V2a INs) was found to fulfill these criteria and make up a fraction of the rhythm-generating population. Here we...... than in cords from controls. Collectively, our findings indicate that excitatory Hb9::Cre-derived INs constitute a distinct population of neurons that participates in the rhythm generating kernel for spinal locomotion....... use Hb9::Cre mice to genetically manipulate Hb9::Cre-derived excitatory interneurons (INs) in order to determine the role of these INs in rhythm generation. We demonstrate that this line captures a consistent population of spinal INs which is mixed with respect to neurotransmitter phenotype...

Acquisition of speech rhythm in a second language by learners with rhythmically different native languages.

Science.gov (United States)

Ordin, Mikhail; Polyanskaya, Leona

2015-08-01

The development of speech rhythm in second language (L2) acquisition was investigated. Speech rhythm was defined as durational variability that can be captured by the interval-based rhythm metrics. These metrics were used to examine the differences in durational variability between proficiency levels in L2 English spoken by French and German learners. The results reveal that durational variability increased as L2 acquisition progressed in both groups of learners. This indicates that speech rhythm in L2 English develops from more syllable-timed toward more stress-timed patterns irrespective of whether the native language of the learner is rhythmically similar to or different from the target language. Although both groups showed similar development of speech rhythm in L2 acquisition, there were also differences: German learners achieved a degree of durational variability typical of the target language, while French learners exhibited lower variability than native British speakers, even at an advanced proficiency level.

Effects of adrenaline on rhythm transitions in out-of-hospital cardiac arrest.

Science.gov (United States)

Neset, Andres; Nordseth, Trond; Kramer-Johansen, Jo; Wik, Lars; Olasveengen, Theresa M

2013-11-01

We wanted to study the effects of intravenous (i.v.) adrenaline (epinephrine) on rhythm transitions during cardiac arrest with initial or secondary ventricular fibrillation/tachycardia (VF/VT). Post hoc analysis of patients included in a randomised controlled trial of i.v. drugs in adult, non-traumatic out-of-hospital cardiac arrest patients who were defibrillated and had a readable electrocardiography recording. Patients who received adrenaline were compared with patients who did not. Cardiac rhythms were annotated manually using the defibrillator data. Eight hundred and forty-nine patients were included in the randomised trial of which 223 were included in this analysis; 119 in the adrenaline group and 104 in the no-adrenaline group. The proportion of patients with one or more VF/VT episodes after temporary return of spontaneous circulation (ROSC) was higher in the adrenaline than in the no-adrenaline group, 24% vs. 12%, P = 0.03. Most relapses from ROSC to VF/VT in the no-adrenaline group occurred during the first 20 min of resuscitation, whereas patients in the adrenaline group experienced such relapses even after 20 min. Fibrillations from asystole or pulseless electrical activity, shock resistant VF/VT and the number of rhythm transitions per patient was higher in the adrenalin group compared with the no-adrenalin group: 90% vs. 69%, P adrenaline had more rhythm transitions from ROSC and non-shockable rhythms to VF/VT. © 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Word-by-word entrainment of speech rhythm during joint story building

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Tommi eHimberg

2015-06-01

Full Text Available Movements and behaviour synchronise during social interaction at many levels, often unintentionally. During smooth conversation, for example, participants adapt to each others' speech rates. Here we aimed to find out to which extent speakers adapt their turn-taking rhythms during a story-building game.Nine sex-matched dyads of adults (12 males, 6 females created two 5-min stories by contributing to them alternatingly one word at a time. The participants were located in different rooms, with audio connection during one story and audiovisual during the other. They were free to select the topic of the story.Although the participants received no instructions regarding the timing of the story building, their word rhythms were highly entrained (R ̅ = 0.70, p < 0.001 even though the rhythms as such were unstable (R ̅ = 0.14 for pooled data. Such high entrainment in the absence of steady word rhythm occurred in every individual story, independently of whether the subjects were connected via audio-only or audiovisual link.The observed entrainment was of similar strength as typical entrainment in finger-tapping tasks where participants are specifically instructed to synchronize their behaviour. Thus speech seems to spontaneously induce strong entrainment between the conversation partners, likely reflecting automatic alignment of their semantic and syntactic processes.

Circadian rhythms regulate amelogenesis.

Science.gov (United States)

Zheng, Li; Seon, Yoon Ji; Mourão, Marcio A; Schnell, Santiago; Kim, Doohak; Harada, Hidemitsu; Papagerakis, Silvana; Papagerakis, Petros

2013-07-01

Ameloblasts, the cells responsible for making enamel, modify their morphological features in response to specialized functions necessary for synchronized ameloblast differentiation and enamel formation. Secretory and maturation ameloblasts are characterized by the expression of stage-specific genes which follows strictly controlled repetitive patterns. Circadian rhythms are recognized as key regulators of the development and diseases of many tissues including bone. Our aim was to gain novel insights on the role of clock genes in enamel formation and to explore the potential links between circadian rhythms and amelogenesis. Our data shows definitive evidence that the main clock genes (Bmal1, Clock, Per1 and Per2) oscillate in ameloblasts at regular circadian (24 h) intervals both at RNA and protein levels. This study also reveals that the two markers of ameloblast differentiation i.e. amelogenin (Amelx; a marker of secretory stage ameloblasts) and kallikrein-related peptidase 4 (Klk4, a marker of maturation stage ameloblasts) are downstream targets of clock genes. Both, Amelx and Klk4 show 24h oscillatory expression patterns and their expression levels are up-regulated after Bmal1 over-expression in HAT-7 ameloblast cells. Taken together, these data suggest that both the secretory and the maturation stages of amelogenesis might be under circadian control. Changes in clock gene expression patterns might result in significant alterations of enamel apposition and mineralization. Copyright © 2013 Elsevier Inc. All rights reserved.

Social memory in the rat: circadian variation and effect of circadian rhythm disruption

NARCIS (Netherlands)

Reijmers, L.G.J.E.; Leus, I.E.; Burbach, J.P.H.; Spruijt, B.M.; Ree, van J.M.

2001-01-01

Disruption of circadian rhythm can impair long-term passive avoidance memory of rats and mice. The present study investigated whether disruption of circadian rhythm can also impair social memory of male rats. Social memory was assessed using the social discrimination test, in which a short-term

The role of feeding rhythm, adrenal hormones and neuronal inputs in synchronizing daily clock gene rhythms in the liver

NARCIS (Netherlands)

Su, Yan; Cailotto, Cathy; Foppen, Ewout; Jansen, Remi; Zhang, Zhi; Buijs, Ruud; Fliers, Eric; Kalsbeek, Andries

2016-01-01

The master clock in the hypothalamic suprachiasmatic nucleus (SCN) is assumed to distribute rhythmic information to the periphery via neural, humoral and/or behavioral connections. Until now, feeding, corticosterone and neural inputs are considered important signals for synchronizing daily rhythms

Rhythms of EEG and cognitive processes

Directory of Open Access Journals (Sweden)

Novikova S.I.

2015-06-01

Full Text Available The study of cognitive processes is regarded to be more effective if it combines a psychological approach with a neurophysiological one. This approach makes it possible to come closer to understanding of the basic mechanisms of different cognitive processes, to describe the patterns of forming these mechanisms in ontogenesis, to investigate the origin of cognitive impairments, and to develop intervention techniques. The promising way of investigating the mechanisms of cognitive functions is the electroencephalography (EEG. This is a non-invasive, safe, and relatively cheap method of research of the functional condition of the brain. The characteristics of EEG rhythms, recorded with different cognitive loads, reflect the processes of functional modulation of neural network activity of the cortex, which serves the neurophysiologic basis for attention, memory and other cognitive processes. The article provides an overview of works containing the analysis of the alpha and theta rhythms’ dynamics in various states of wakefulness. It also introduces the substantiation of methodology of functional regulatory approach to the interpretation of behaviors of EEG rhythms.

Action experience, more than observation, influences mu rhythm desynchronization.

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Erin N Cannon

Full Text Available Since the discovery of mirror neurons in premotor and parietal areas of the macaque monkey, the idea that action and perception may share the same neural code has been of central interest in social, developmental, and cognitive neurosciences. A fundamental question concerns how a putative human mirror neuron system may be tuned to the motor experiences of the individual. The current study tested the hypothesis that prior motor experience modulated the sensorimotor mu and beta rhythms. Specifically, we hypothesized that these sensorimotor rhythms would be more desynchronized after active motor experience compared to passive observation experience. To test our hypothesis, we collected EEG from adult participants during the observation of a relatively novel action: an experimenter used a claw-like tool to pick up a toy. Prior to EEG collection, we trained one group of adults to perform this action with the tool (performers. A second group comprised trained video coders, who only had experience observing the action (observers. Both the performers and the observers had no prior motor and visual experience with the action. A third group of novices was also tested. Performers exhibited the greatest mu rhythm desynchronization in the 8-13 Hz band, particularly in the right hemisphere compared to observers and novices. This study is the first to contrast active tool-use experience and observation experience in the mu rhythm and to show modulation with relatively shorter amounts of experience than prior mirror neuron expertise studies. These findings are discussed with respect to its broader implication as a neural signature for a mechanism of early social learning.

Depletion of endogenous germ cells in tree shrews in preparation for spermatogonial transplantation.

Science.gov (United States)

Liu, Tingting; Guo, Ying; Yan, Lanzhen; Sun, Bin; Zheng, Ping; Zhao, Xudong

2017-09-01

To achieve successful spermatogonial transplantation, endogenous germ cells must be depleted in recipient animals to allow donor germ cells to colonize efficiently. Busulfan is commonly used for the depletion of endogenous germ cells in recipient males. However, the optimal dose of busulfan is species-specific, and the optimal dose in tree shrews is yet to be determined. The current study aimed to determine the optimal dose of busulfan for effective suppression of endogenous spermatogenesis in tree shrews. Different doses (15, 20, 25, 30, 35, 40 and 45 mg/kg) of busulfan were injected into tree shrews intraperitoneally. Survival rates of the different treatment groups were calculated at 2 weeks and body weights were measured at 4, 6, 8, 10 and 28 weeks post-busulfan treatment. The testes were also removed and weighed at 4, 6, 8, 10 and 28 weeks post-treatment, and the cross and longitude diameters of the testes and diameters of the seminiferous tubules were measured and histologically evaluated. It was observed that there were no significant differences in the survival rates between the 15-35 mg/kg treatment groups and the control group (P>0.05), while the survival rate of the 40 mg/kg treatment group significantly decreased relative to the control group (Pendogenous germ cells in tree shrews. This dose led to maximum suppression of endogenous spermatogenesis while maintaining an acceptable survival rate of >50% of the lethal dose of busulfan for tree shrews.

Circadian rhythm of pineal uptake of 32P in domestic fowl

International Nuclear Information System (INIS)

Sackman, J.W.

1977-01-01

The uptake of radioactive phosphorus by the pineal gland in White Leghorn cockerels (Gallus domesticus) showed a diurnal variation with maxima in the light phase and minima in the dark phase of the light: dark cycle. Constant light caused the rhythm to disappear while constant dark had no effect other than lowering the amplitude of the variations. These data indicate that the rhythm in pineal uptake of 32 P is circadian. (author)

Adrenal, thyroid, and testicular hormone rhythms in male golden hamsters on long and short days

International Nuclear Information System (INIS)

Ottenweller, J.E.; Tapp, W.N.; Pitman, D.L.; Natelson, B.H.

1987-01-01

Plasma concentrations of adrenal, thyroid, and testicular hormones were measured at 4-h intervals around the clock in male hamsters on long (14:10-h light-dark cycle) and short (10:14-h light-dark cycle) days. Plasma corticosterone, cortisol, thyroxine (T 4 ), triiodothyronine (T 3 ), and testosterone rhythms were present on long days. The only one of these hormones to have a significant rhythm on short days was cortisol, but even its amplitude was suppressed compared with the cortisol rhythm on long days. Short days also lowered mean plasma levels of cortisol, T 4 , T 3 , and testosterone. Finally, short days raised the ratio of corticosterone to cortisol and lowered the ratio of T 4 to T 3 . Both ratios had significant rhythms on long days but not on short days. Because of the many interactions among adrenal, thyroid, and testicular hormone axes, it is unclear whether the primary effect of short days is on one of these endocrine systems or on another factor that has separate effects on each of the hormone rhythms that was measured. Nonetheless, it is clear that a major effect of short day lengths in hamsters is to suppress hormone rhythms. Explanations of photoperiodic effects that depend on endocrine mediation should take this into account

Feeding cycle-dependent circulating insulin fluctuation is not a dominant Zeitgeber for mouse peripheral clocks except in the liver: Differences between endogenous and exogenous insulin effects.

Science.gov (United States)

Oishi, Katsutaka; Yasumoto, Yuki; Higo-Yamamoto, Sayaka; Yamamoto, Saori; Ohkura, Naoki

2017-01-29

The master clock in the suprachiasmatic nucleus synchronizes peripheral clocks via humoral and neural signals in mammals. Insulin is thought to be a critical Zeitgeber (synchronizer) for peripheral clocks because it induces transient clock gene expression in cultured cells. However, the extent to which fluctuations in feeding-dependent endogenous insulin affect the temporal expression of clock genes remains unclear. We therefore investigated the temporal expression profiles of clock genes in the peripheral tissues of mice fed for 8 h during either the daytime (DF) or the nighttime (NF) for one week to determine the involvement of feeding cycle-dependent endogenous insulin rhythms in the circadian regulation of peripheral clocks. The phase of circulating insulin fluctuations was reversed in DF compared with NF mice, although those of circulating corticosterone fluctuations and nocturnal locomotor activity were identical between these mice. The reversed feeding cycle affected the circadian phases of Per1 and Per2 gene expression in the liver and not in heart, lung, white adipose and skeletal muscle tissues. On the other hand, injected exogenous insulin significantly induced Akt phosphorylation in the heart and skeletal muscle as well as the liver, and significantly induced Per1 and Per2 gene expression in all examined tissues. These findings suggest that feeding cycles and feeding cycle-dependent endogenous insulin fluctuations are not dominant entrainment signals for peripheral clocks other than the liver, although exogenous insulin might reset peripheral oscillators in mammals. Copyright © 2016 Elsevier Inc. All rights reserved.

Time management in a co-housed social rodent species (Arvicanthis niloticus).

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Castillo-Ruiz, Alexandra; Indic, Premananda; Schwartz, William J

2018-01-19

Sociality has beneficial effects on fitness, and timing the activities of animals may be critical. Social cues could influence daily rhythmic activities via direct effects on the circadian clock or on processes that bypass it (masking), but these possibilities remain incompletely addressed. We investigated the effects of social cues on the circadian body temperature (Tb) rhythms in pairs of co-housed and isolated grass rats, Arvicanthis niloticus (a social species), in constant darkness (DD). Cohabitation did not induce synchronization of circadian Tb rhythms. However, socio-sexual history did affect circadian properties: accelerating the clock in sexually experienced males and females in DD and advancing rhythm phase in the females in a light-dark cycle. To address whether synchronization occurs at an ultradian scale, we analyzed Tb and activity rhythms in pairs of co-housed sisters or couples in DD. Regardless of pair type, co-housing doubled the percentage of time individuals were simultaneously active without increasing individual activity levels, suggesting that activity bouts were synchronized by redistribution over 24 h. Together, our laboratory findings show that social cues affect individual "time allocation" budgets via mechanisms at multiple levels of biological organization. We speculate that in natural settings these effects could be adaptive, especially for group-living animals.

A Norway spruce FLOWERING LOCUS T homolog is implicated in control of growth rhythm in conifers.

Science.gov (United States)

Gyllenstrand, Niclas; Clapham, David; Källman, Thomas; Lagercrantz, Ulf

2007-05-01

Growth in perennial plants possesses an annual cycle of active growth and dormancy that is controlled by environmental factors, mainly photoperiod and temperature. In conifers and other nonangiosperm species, the molecular mechanisms behind these responses are currently unknown. In Norway spruce (Picea abies L. Karst.) seedlings, growth cessation and bud set are induced by short days and plants from southern latitudes require at least 7 to 10 h of darkness, whereas plants from northern latitudes need only 2 to 3 h of darkness. Bud burst, on the other hand, is almost exclusively controlled by temperature. To test the possible role of Norway spruce FLOWERING LOCUS T (FT)-like genes in growth rhythm, we have studied expression patterns of four Norway spruce FT family genes in two populations with a divergent bud set response under various photoperiodic conditions. Our data show a significant and tight correlation between growth rhythm (both bud set and bud burst), and expression pattern of one of the four Norway spruce phosphatidylethanolamine-binding protein gene family members (PaFT4) over a variety of experimental conditions. This study strongly suggests that one Norway spruce homolog to the FT gene, which controls flowering in angiosperms, is also a key integrator of photoperiodic and thermal signals in the control of growth rhythms in gymnosperms. The data also indicate that the divergent adaptive bud set responses of northern and southern Norway spruce populations, both to photoperiod and light quality, are mediated through PaFT4. These results provide a major advance in our understanding of the molecular control of a major adaptive trait in conifers and a tool for further molecular studies of adaptive variation in plants.

Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate.

Science.gov (United States)

Koch, Sabine C; Rautner, Helena

2017-11-29

In the context of embodiment research, there has been a growing interest in phenomena of interpersonal resonance. Given that haptic communication is particularly under-researched, we focused on the phenomenon of embracing. When we embrace a dear friend to say good-bye at the end of a great evening, we typically first employ smooth and yielding movements with round transitions between muscular tensing and relaxing ( smooth , indulging rhythms ), and when the embrace is getting too long, we start to use slight patting ( sharp , fighting rhythms with sharp transitions) on the back or the shoulders of the partner in order to indicate that we now want to end the embrace. On the ground of interpersonal resonance, most persons (per-sonare, latin = to sound through) understand these implicit nonverbal signals, expressed in haptic tension-flow changes, and will react accordingly. To experimentally test the hypothesis that smooth, indulgent rhythms signal the wish to continue, and sharp, fighting rhythms signal the wish to separate from an embrace, we randomly assigned 64 participants, all students at the University of Heidelberg, to two differently sequenced embrace conditions: (a) with the fighting rhythm at the end of the sequence of two indulgent rhythms (Sequence A: smooth-smooth-sharp); and (b) with the fighting rhythm between two indulgent rhythms (Sequence B: smooth-sharp-smooth). Participants were embraced for 30 s by a female confe-derate with their eyes blindfolded to focus on haptic and kinesthetic cues without being distracted by visual cues. They were instructed to let go of a handkerchief that they held between the fingers of their dominant hand during the embrace, when they felt that the embracer signaled the wish to finish the embrace. Participants significantly more often dropped the handkerchief in the phase of the fighting rhythm, no matter in which location it occurred in the embrace sequence. We assume that we learn such rhythmic behaviors and their

Absence of Circadian Rhythms of Preterm Premature Rupture of Membranes and Preterm Placental Abruption

Science.gov (United States)

Luque-Fernandez, Miguel Angel; Ananth, Cande V.; Sanchez, Sixto E.; Qiu, Chun-fang; Hernandez-Diaz, Sonia; Valdimarsdottir, Unnur; Gelaye, Bizu; Williams, Michelle A.

2014-01-01

Purpose Data regarding circadian rhythm in the onset of spontaneous preterm premature rupture of membranes (PROM) and placental abruption (PA) cases are conflicting. We modeled the time of onset of preterm PROM and PA cases and examined if the circadian profiles varied based on the gestational age at delivery. Methods We used parametric and nonparametric methods, including trigonometric regression in the framework of generalized linear models, to test the presence of circadian rhythms in the time of onset of preterm PROM and PA cases, among 395 women who delivered a singleton between 2009 and 2010 in Lima, Peru. Results We found a diurnal circadian pattern, with a morning peak at 07h:32’ (95%CI:05h:46’ – 09h:18’) among moderate preterm PROM cases (P-value<0.001), and some evidence of a diurnal circadian periodicity among PA cases in term infants (P-value=0.067). However, we did not find evidence of circadian rhythms in the time of onset of extremely or very preterm PROM (P-value=0.259) and preterm PA (P-value=0.224). Conclusions The circadian rhythms of the time of onset of preterm PROM and PA cases varied based on gestational weeks at delivery. While circadian rhythms were presented among moderate preterm PROM and term PA cases, there was no evidence of circadian rhythms among preterm PA and very or extremely preterm PROM cases, underlying other mechanisms associated with the time of onset. PMID:25453346

Interaction between endogenous and exogenous orienting in crossmodal attention.

Science.gov (United States)

Chen, Xiaoxi; Chen, Qi; Gao, Dingguo; Yue, Zhenzhu

2012-08-01

Using a cue-target paradigm, we investigated the interaction between endogenous and exogenous orienting in cross-modal attention. A peripheral (exogenous) cue was presented after a central (endogenous) cue with a variable time interval. The endogenous and exogenous cues were presented in one sensory modality (auditory in Experiment 1 and visual in Experiment 2) whereas the target was presented in another modality. Both experiments showed a significant endogenous cuing effect (longer reaction times in the invalid condition than in the valid condition). However, exogenous cuing produced a facilitatory effect in both experiments in response to the target when endogenous cuing was valid, but it elicited a facilitatory effect in Experiment 1 and an inhibitory effect in Experiment 2 when endogenous cuing was invalid. These findings indicate that endogenous and exogenous cuing can co-operate in orienting attention to the crossmodal target. Moreover, the interaction between endogenous and exogenous orienting of attention is modulated by the modality between the cue and the target. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

Effect of Spaceflight on the Circadian Rhythm, Lifespan and Gene Expression of Drosophila melanogaster

Science.gov (United States)

Xu, Kanyan

2015-01-01

Space travelers are reported to experience circadian rhythm disruption during spaceflight. However, how the space environment affects circadian rhythm is yet to be determined. The major focus of this study was to investigate the effect of spaceflight on the Drosophila circadian clock at both the behavioral and molecular level. We used China’s Shenzhou-9 spaceship to carry Drosophila. After 13 days of spaceflight, behavior tests showed that the flies maintained normal locomotor activity rhythm and sleep pattern. The expression level and rhythm of major clock genes were also unaffected. However, expression profiling showed differentially regulated output genes of the circadian clock system between space flown and control flies, suggesting that spaceflight affected the circadian output pathway. We also investigated other physiological effects of spaceflight such as lipid metabolism and lifespan, and searched genes significantly affected by spaceflight using microarray analysis. These results provide new information on the effects of spaceflight on circadian rhythm, lipid metabolism and lifespan. Furthermore, we showed that studying the effect of spaceflight on gene expression using samples collected at different Zeitgeber time could obtain different results, suggesting the importance of appropriate sampling procedures in studies on the effects of spaceflight. PMID:25798821

Effect of spaceflight on the circadian rhythm, lifespan and gene expression of Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Lingling Ma

Full Text Available Space travelers are reported to experience circadian rhythm disruption during spaceflight. However, how the space environment affects circadian rhythm is yet to be determined. The major focus of this study was to investigate the effect of spaceflight on the Drosophila circadian clock at both the behavioral and molecular level. We used China's Shenzhou-9 spaceship to carry Drosophila. After 13 days of spaceflight, behavior tests showed that the flies maintained normal locomotor activity rhythm and sleep pattern. The expression level and rhythm of major clock genes were also unaffected. However, expression profiling showed differentially regulated output genes of the circadian clock system between space flown and control flies, suggesting that spaceflight affected the circadian output pathway. We also investigated other physiological effects of spaceflight such as lipid metabolism and lifespan, and searched genes significantly affected by spaceflight using microarray analysis. These results provide new information on the effects of spaceflight on circadian rhythm, lipid metabolism and lifespan. Furthermore, we showed that studying the effect of spaceflight on gene expression using samples collected at different Zeitgeber time could obtain different results, suggesting the importance of appropriate sampling procedures in studies on the effects of spaceflight.

Identification of pyrG Used as an Endogenous Reference Gene in Qualitative and Real-Time Quantitative PCR Detection of Pleurotus ostreatus.

Science.gov (United States)

Zheng, Shi; Shan, Luying; Zhuang, Yongliang; Shang, Ying

2018-03-01

As a well-known edible fungus rich in nutrients, Pleurotus ostreatus has been used as an alternative to expensive wild edible fungi. Specifically, the fact that using P. ostreatus instead of other expensive wild edible fungi has damaged the rights and interests of consumers. Among the existing methods for detection of food adulteration, the amplification of endogenous reference gene is the most accurate method. However, an ideal endogenous reference gene for P. ostreatus has yet to be developed. In this study, a DNA extraction method for P. ostreatus was optimized, and pyrG was selected as a species-specific gene through sequence alignment. This gene was subsequently subjected to qualitative and quantitative Polymerase Chain Reaction (PCR) assays with 3 different P. ostreatus varieties and 7 other species. A low detection limit of 5 pg/μL was obtained by TaqMan quantitative PCR, and no pyrG amplification product was observed in the 7 other species. No allelic variation was detected in P. ostreatus varieties. These experiments confirmed that pyrG was an ideal endogenous reference gene for the qualitative and real-time quantitative PCR detection of P. ostreatus. This method was also suitable for the examination of processed P. ostreatus samples and determination of adulteration in wild mushrooms. The pyrG gene was chosen as an ideal endogenous reference gene for the qualitative and real-time quantitative PCR detection of P. ostreatus, and the detection limit was 5 pg/μL for the quantification. This method is used not only for raw materials but also for processed P. ostreatus products and other processed mushroom foods. © 2018 Institute of Food Technologists®.

Rhythm-based Analysis As A Different Way Of Viewing Work Life In A School

DEFF Research Database (Denmark)

Clausen, Jacob

This abstract is about rhythms and how professionals struggle to balance two categories of rhythms in a public school. The teachers at this school clearly expressed that they had a common denominator in regards to their work life, being that they did not have enough time to do their work....... Their understanding of time were always audible and they were very verbal about their frustrations in relation to time (pressure). The full article is about rhythms in a specific public school as a way to gather a new perspective on work life....

Are human endogenous retroviruses triggers of autoimmune diseases?

DEFF Research Database (Denmark)

Nexø, Bjørn A; Villesen, Palle; Nissen, Kari K

2016-01-01

factors. Viruses including human endogenous retroviruses have long been linked to the occurrence of autoimmunity, but never proven to be causative factors. Endogenous viruses are retroviral sequences embedded in the host germline DNA and transmitted vertically through successive generations in a Mendelian...... manner. In this study by means of genetic epidemiology, we have searched for the involvement of endogenous retroviruses in three selected autoimmune diseases: multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. We found that at least one human endogenous retroviral locus...

Contagion risk in endogenous financial networks

International Nuclear Information System (INIS)

Li, Shouwei; Sui, Xin

2016-01-01

Highlights: • We propose an endogenous financial network model. • Endogenous networks include interbank networks, inter-firm networks and bank-firm networks. • We investigate contagion risk in endogenous financial networks. - Abstract: In this paper, we investigate contagion risk in an endogenous financial network, which is characterized by credit relationships connecting downstream and upstream firms, interbank credit relationships and credit relationships connecting firms and banks. The findings suggest that: increasing the number of potential lenders randomly selected can lead to an increase in the number of bank bankruptcies, while the number of firm bankruptcies presents a trend of increase after the decrease; after the intensity of choice parameter rises beyond a threshold, the number of bankruptcies in three sectors (downstream firms, upstream firms and banks) shows a relatively large margin of increase, and keeps at a relatively high level; there exists different trends for bankruptcies in different sectors with the change of the parameter of credits’ interest rates.

Endogenous price flexibility and optimal monetary policy

OpenAIRE

Ozge Senay; Alan Sutherland

2014-01-01

Much of the literature on optimal monetary policy uses models in which the degree of nominal price flexibility is exogenous. There are, however, good reasons to suppose that the degree of price flexibility adjusts endogenously to changes in monetary conditions. This article extends the standard new Keynesian model to incorporate an endogenous degree of price flexibility. The model shows that endogenizing the degree of price flexibility tends to shift optimal monetary policy towards complete i...

Temporal correlation between auditory neurons and the hippocampal theta rhythm induced by novel stimulations in awake guinea pigs.

Science.gov (United States)

Liberman, Tamara; Velluti, Ricardo A; Pedemonte, Marisa

2009-11-17

The hippocampal theta rhythm is associated with the processing of sensory systems such as touch, smell, vision and hearing, as well as with motor activity, the modulation of autonomic processes such as cardiac rhythm, and learning and memory processes. The discovery of temporal correlation (phase locking) between the theta rhythm and both visual and auditory neuronal activity has led us to postulate the participation of such rhythm in the temporal processing of sensory information. In addition, changes in attention can modify both the theta rhythm and the auditory and visual sensory activity. The present report tested the hypothesis that the temporal correlation between auditory neuronal discharges in the inferior colliculus central nucleus (ICc) and the hippocampal theta rhythm could be enhanced by changes in sensory stimulation. We presented chronically implanted guinea pigs with auditory stimuli that varied over time, and recorded the auditory response during wakefulness. It was observed that the stimulation shifts were capable of producing the temporal phase correlations between the theta rhythm and the ICc unit firing, and they differed depending on the stimulus change performed. Such correlations disappeared approximately 6 s after the change presentation. Furthermore, the power of the hippocampal theta rhythm increased in half of the cases presented with a stimulation change. Based on these data, we propose that the degree of correlation between the unitary activity and the hippocampal theta rhythm varies with--and therefore may signal--stimulus novelty.

Reducing language to rhythm: Amazonian Bora drummed language exploits speech rhythm for long-distance communication

Science.gov (United States)

Seifart, Frank; Meyer, Julien; Grawunder, Sven; Dentel, Laure

2018-04-01

Many drum communication systems around the world transmit information by emulating tonal and rhythmic patterns of spoken languages in sequences of drumbeats. Their rhythmic characteristics, in particular, have not been systematically studied so far, although understanding them represents a rare occasion for providing an original insight into the basic units of speech rhythm as selected by natural speech practices directly based on beats. Here, we analyse a corpus of Bora drum communication from the northwest Amazon, which is nowadays endangered with extinction. We show that four rhythmic units are encoded in the length of pauses between beats. We argue that these units correspond to vowel-to-vowel intervals with different numbers of consonants and vowel lengths. By contrast, aligning beats with syllables, mora or only vowel length yields inconsistent results. Moreover, we also show that Bora drummed messages conventionally select rhythmically distinct markers to further distinguish words. The two phonological tones represented in drummed speech encode only few lexical contrasts. Rhythm thus appears to crucially contribute to the intelligibility of drummed Bora. Our study provides novel evidence for the role of rhythmic structures composed of vowel-to-vowel intervals in the complex puzzle concerning the redundancy and distinctiveness of acoustic features embedded in speech.

Crude fucoidan content in two North Atlantic kelp species, Saccharina latissima and Laminaria digitata - seasonal variation and impact of environmental factors

DEFF Research Database (Denmark)

Bruhn, Annette; Janicek, Tina; Manns, Dirk Martin

2017-01-01

, the biochemical composition of brown algae displays a seasonal fluctuation driven by environmental factors and endogenous rhythms. To cultivate and harvest kelps with high yields of fucoidans, knowledge is needed on seasonal variation and impact of environmental conditions on the fucoidan content of brown algae....... The relations between the fucoidan content and key environmental factors (irradiance, nutrient availability, salinity and exposure) were examined by sampling natural populations of the common North Atlantic kelps, Saccharina latissima and Laminaria digitata, over a full year at Hanstholm in the North Sea...

The Role of Rhythm in Speech and Language Rehabilitation: The SEP Hypothesis.

Science.gov (United States)

Fujii, Shinya; Wan, Catherine Y

2014-01-01

For thousands of years, human beings have engaged in rhythmic activities such as drumming, dancing, and singing. Rhythm can be a powerful medium to stimulate communication and social interactions, due to the strong sensorimotor coupling. For example, the mere presence of an underlying beat or pulse can result in spontaneous motor responses such as hand clapping, foot stepping, and rhythmic vocalizations. Examining the relationship between rhythm and speech is fundamental not only to our understanding of the origins of human communication but also in the treatment of neurological disorders. In this paper, we explore whether rhythm has therapeutic potential for promoting recovery from speech and language dysfunctions. Although clinical studies are limited to date, existing experimental evidence demonstrates rich rhythmic organization in both music and language, as well as overlapping brain networks that are crucial in the design of rehabilitation approaches. Here, we propose the "SEP" hypothesis, which postulates that (1) "sound envelope processing" and (2) "synchronization and entrainment to pulse" may help stimulate brain networks that underlie human communication. Ultimately, we hope that the SEP hypothesis will provide a useful framework for facilitating rhythm-based research in various patient populations.

Sleep- and circadian rhythm-associated pathways as therapeutic targets in bipolar disorder.

Science.gov (United States)

Bellivier, Frank; Geoffroy, Pierre-Alexis; Etain, Bruno; Scott, Jan

2015-06-01

Disruptions in sleep and circadian rhythms are observed in individuals with bipolar disorders (BD), both during acute mood episodes and remission. Such abnormalities may relate to dysfunction of the molecular circadian clock and could offer a target for new drugs. This review focuses on clinical, actigraphic, biochemical and genetic biomarkers of BDs, as well as animal and cellular models, and highlights that sleep and circadian rhythm disturbances are closely linked to the susceptibility to BDs and vulnerability to mood relapses. As lithium is likely to act as a synchronizer and stabilizer of circadian rhythms, we will review pharmacogenetic studies testing circadian gene polymorphisms and prophylactic response to lithium. Interventions such as sleep deprivation, light therapy and psychological therapies may also target sleep and circadian disruptions in BDs efficiently for treatment and prevention of bipolar depression. We suggest that future research should clarify the associations between sleep and circadian rhythm disturbances and alterations of the molecular clock in order to identify critical targets within the circadian pathway. The investigation of such targets using human cellular models or animal models combined with 'omics' approaches are crucial steps for new drug development.

Circadian disc shedding in Xenopus retina in vitro

International Nuclear Information System (INIS)

Flannery, J.G.; Fisher, S.K.

1984-01-01

To further examine the endogenous rhythm of disc shedding and phagocytosis observed in several species, adult Xenopus were entrained to a 12 hr light/12 hr dark cycle and then placed in constant darkness. At various times during a 3-day period of constant darkness, eyes were explanted and placed into culture medium, then processed for light and electron microscopy. A clear rhythmicity of disc shedding was observed, with pronounced peaks at the times light onset occurred in the original entrainment cycle. Modification of the HCO 3 - ion concentration in the medium was found to raise the amplitude of the peak of endogenous disc shedding. Explants maintained in culture medium containing deuterium oxide (a compound known to perturb circadian oscillators) were found to shed with a longer interval between peaks. The addition of the protein synthesis inhibitor, anisomycin, to this preparation suppressed the shedding rhythm. The action of anisomycin was investigated by autoradiographic examination of the pattern of 3 H-leucine uptake and protein synthesis by the explant. The findings suggest the presence of a circadian oscillator for rhythmic disc shedding within the amphibian eye

Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment

Energy Technology Data Exchange (ETDEWEB)

Kaper, Tasso J., E-mail: tasso@bu.edu; Kramer, Mark A., E-mail: mak@bu.edu [Department of Mathematics and Statistics, Boston University, Boston, Massachusetts 02215 (United States); Rotstein, Horacio G., E-mail: horacio@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

2013-12-15

Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases.

Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment

International Nuclear Information System (INIS)

Kaper, Tasso J.; Kramer, Mark A.; Rotstein, Horacio G.

2013-01-01

Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases

Mozart, Mozart Rhythm and Retrograde Mozart Effects: Evidences from Behaviours and Neurobiology Bases.

Science.gov (United States)

Xing, Yingshou; Xia, Yang; Kendrick, Keith; Liu, Xiuxiu; Wang, Maosen; Wu, Dan; Yang, Hua; Jing, Wei; Guo, Daqing; Yao, Dezhong

2016-01-21

The phenomenal finding that listening to Mozart K.448 enhances performance on spatial tasks has motivated a continuous surge in promoting music education over the past two decades. But there have been inconsistent reports in previous studies of the Mozart effect. Here conducted was a systematic study, with Mozart and retrograde Mozart music, Mozart music rhythm and pitch, behaviours and neurobiology tests, rats and humans subjects. We show that while the Mozart K.448 has positive cognitive effects, the retrograde version has a negative effect on rats' performance in the Morris water maze test and on human subjects' performance in the paper folding and cutting test and the pencil-and-paper maze test. Such findings are further confirmed by subsequent immunohistochemical analyses in rats on the neurogenesis and protein levels of BDNF and its receptor, TrkB. Furthermore, when the rhythm and pitch of the normal and retrograde Mozart music are manipulated independently, the learning performance of the rats in the Morris water maze test indicated that rhythm is a crucial element in producing the behavioural effects. These findings suggest that the nature of Mozart effect is the Mozart rhythm effect, and indicate that different music may have quite different to opposite effects. Further study on rhythm effect may provide clues to understand the common basis over animals from rats to humans.

Endogenous Pyrogen Physiology.

Science.gov (United States)

Beisel, William R.

1980-01-01

Discusses the physiology of endogenous pyrogen (EP), the fever-producing factor of cellular origin. Included are: its hormone-like role, its molecular nature, bioassay procedures, cellular production and mechanisms of EP action. (SA)

Parkinsonian syndromes presenting with circadian rhythm sleep disorder- advanced sleep-phase type.

Science.gov (United States)

Shukla, Garima; Kaul, Bhavna; Gupta, Anupama; Goyal, Vinay; Behari, Madhuri

2015-01-01

Circadian rhythm sleep disorder-advanced sleep-phase type is a relatively uncommon disorder, mostly seen among the elderly population. Impaired circadian rhythms have been reported in neurodegenerative conditions; however, there are no reports of any circadian rhythm sleep disorder among patients with Parkinsonian syndromes. We report two patients who presented with this circadian rhythm disorder, and were then diagnosed with a Parkinsonian syndrome. The cases. A 65-year-old retired man presented with history of abrupt change in sleep schedules, sleeping around 6.30-7 p.m. and waking up around 3-4 a.m. for the last 2 months. On detailed examination, the patient was observed to have symmetrical bradykinesia and cogwheel rigidity of limbs. A diagnosis of multiple system atrophy was made, supported by MRI findings and evidence of autonomic dysfunction. Symptoms of change in sleep-wake cycles resolved over the next 1 year, while the patient was treated with dopaminergic therapy. A 47-year-old man, who was being evaluated for presurgical investigation for refractory temporal lobe epilepsy, presented with complaints suggestive of dysarthria, bradykinesia of limbs and frequent falls for 5 months. Simultaneously, he began to sleep around 7 p.m. and wake up at about 2-3 a.m. Examination revealed severe axial rigidity, restricted vertical gaze and bradykinesia of limbs. A diagnosis of progressive supranuclear palsy was made. This is the first report of Parkinson's plus syndromes presenting with a circadian rhythm sleep disorder-advanced sleep-phase type. More prospective assessment for circadian sleep disorders may introduce useful insights into similar associations. Copyright 2015, NMJI.