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Results 201 - 250 of 1344
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Vaze Koustubh M - - 2013
Circadian rhythms are believed to be an evolutionary adaptation to daily environmental cycles resulting from Earth's rotation about its axis. A trait evolved through a process of natural selection is considered as adaptation; therefore, rigorous demonstration of adaptation requires evidence suggesting evolution of a trait by natural selection. Like any ...
Brooks Elisabeth - - 2013
BROOKS, E. and M. M. Canal. Development of circadian rhythms: Role of postnatal light environment. NEUROSCI BIOBEHAV REV XX(X) XXX-XXX, 2013.-Mammals are born with an immature circadian system, which completes its development postnatally. Evidence suggests that the environment experienced by a newborn will impact and shape its development, which will ...
Anderson George - - 2013
Life forms populating the Earth must face environmental challenges to assure individual and species survival. The strategies predisposed to maintain organismal homeostasis and grant selective advantage rely on anticipatory phenomena facing periodic modifications, and compensatory phenomena facing unpredictable changes. Biological processes bringing about these responses are respectively driven by the ...
Kinmonth-Schultz Hannah A HA Department of Biology, University of Washington, Seattle, WA 98195-1800, - - 2013
The plant circadian clock is involved in the regulation of numerous processes. It serves as a timekeeper to ensure that the onset of key developmental events coincides with the appropriate conditions. Although internal oscillating clock mechanisms likely evolved in response to the earth's predictable day and night cycles, organisms must ...
Weigl Yuval - - 2013
The circadian system of mammals regulates the timing of occurrence of behavioral and physiological events, thereby optimizing adaptation to their surroundings. This system is composed of a single master pacemaker located in the suprachiasmatic nucleus (SCN) and a population of peripheral clocks. The SCN integrates time information from exogenous sources ...
Ji Lin - - 2013
The effect of common noise on the collective behavior of circadian oscillation systems was studied in an elementary circadian clock model. It is shown that common noise could induce synchronous oscillations in two uncoupled non-identical systems in the deterministic stable steady state region. The synchronicity of common noise induced oscillations ...
Nierhaus Till - - 2013
During simultaneous EEG-fMRI acquisition, the EEG signal suffers from tremendous artifacts caused by the scanner "environment". Particularly, gradient artifacts and the ballistocardiogram have been well characterized, along with methods to eliminate them. Here, we describe another systematic artifact in the EEG signal, which is induced by the internal ventilation system ...
Negoro Hiromitsu - - 2013
PURPOSE: Mammals urinate less frequently during sleep period than during awake period, which is modulated by triad factors; decreased arousal level in the brain, decreased urine production rate from the kidneys, and increased functional bladder capacity during sleep. The circadian clock ('the clock') is genetic transcription-translation feedback machinery. The clock ...
Battelle Barbara-Anne BA The Whitney Laboratory for Marine Bioscience, 9505 Ocean Shore Blvd, St Augustine, FL 32080-8610, USA. - - 2013
Dark and light adaptation in photoreceptors involve multiple processes including those that change protein concentrations at photosensitive membranes. Light- and dark-adaptive changes in protein levels at rhabdoms have been described in detail in white-eyed Drosophila maintained under artificial light. Here we tested whether protein levels at rhabdoms change significantly in ...
Hart Gerald W GW Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205-2185, USA. - - 2013
While cellular circadian clocks are set by the light/dark cycle, these clocks can be reset by what we eat. Two papers in this issue of Cell Metabolism reveal that O-GlcNAcylation of clock proteins, which is dependent on nutrients, adjusts our circadian clock (Kaasik et al., 2013; Li et al., 2013).
Guo Qing-Hua - - 2013
A photonic angular momentum state (PAMS) with a topological charge of m≠±1 is dipole forbidden at all polarizations of free-space incidence due to the existence of a unique helical phase. We show that by indirectly exciting dark PAMSs through coupling with a bright resonant element, a sharply variant transmission behavior ...
Abraham U - - 2013
Many physiological and behavioral processes such as sleep and wakefulness, hormone secretion, and olfactory sensitivity exhibit a 24-h rhythmicity that persists in constant conditions with a period close to (circa) 24 h. These circadian rhythms are driven by a network of endogenous clocks residing in various tissues, including the olfactory ...
Breslow Emily R - - 2013
Melatonin is endogenously produced and released in humans during nighttime darkness and is suppressed by ocular light exposure. Exogenous melatonin is used to induce circadian phase shifts and sleep. The circadian phase-shifting ability of a stimulus (e.g., melatonin or light) relative to its timing may be displayed as a phase ...
Zhao Xuan - - 2013
Central circadian clock oscillators, located in the suprachiasmatic nucleus (SCN) of the hypothalamus, align peripheral clock systems with geosynchronous time. Gerber et al. (2013) identify actin polymerization and serum response factor (SRF) activation as key steps linking the central master clock to peripheral oscillators.
Bechtold David A DA University of Manchester, Manchester, UK. - - 2013
Daily rhythms are evident across our physiology, ranging from overt behavioural patterns like sleep to intricate molecular rhythms in epigenetic coding. Driving these rhythms at an anatomical and cellular level are circadian clock networks comprising core clock genes and an ever-expanding list of clock-controlled genes. Research over the past decade ...
Juárez Claudia - - 2013
In rabbit pups, nursing by the mother is the prevailing entraining signal for their circadian rhythms during at least the first two weeks of life. Therefore, they are considered a natural model of food anticipatory activity. However, the photic entrainment of the circadian system in rabbit pups during this developmental ...
Rund-Kangisser Shlomit - - 2013
The circadian (~24 h) clock has an enormous influence on the biology of plants and controls a plethora of processes including growth, photosynthesis, photoperiodic flowering and transcription of more than 30% of the genome. The oscillator mechanism that generates these circadian rhythms consists of interlocking feedback loops. CIRCADIAN CLOCK ASSOCIATED ...
Bonsall David R - - 2013
The environmental day-night cycle provides the principal synchronizing signal for behavioral activity in most mammals. Light information is relayed to the master circadian pacemaker, the suprachiasmatic nucleus (SCN), via synaptic transmission from the retina directly to the SCN, where a predominately glutamate-driven cellular signaling pathway is able to reset biochemical, ...
Roenneberg Till - - 2013
The circadian clock can only reliably fulfil its function if it is stably entrained. Most clocks use the light-dark cycle as environmental signal (zeitgeber) for this active synchronisation. How we think about clock function and entrainment has been strongly influenced by the early concepts of the field's pioneers, and the ...
Paladino Natalia - - 2013
The relation between circadian dysregulation and cancer incidence and progression has become a topic of major interest over the last decade. Also, circadian timing has gained attention regarding the use of chronopharmacology-based therapeutics. Given its lack of functional T lymphocytes, due to a failure in thymus development, mice carrying ...
Song Chunyang - - 2013
The score is a symbolic encoding that describes a piece of music, written according to the conventions of music theory, which must be rendered as sound (e.g., by a performer) before it may be perceived as music by the listener. In this paper we provide a step towards unifying music ...
Buhr Ethan D - - 2013
Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. This is achieved by ocular photoreception relaying signals to the suprachiasmatic nucleus (SCN) in the hypothalamus. Signals from the SCN cause the synchronization of independent circadian clocks throughout the body to appropriate phases. Signals ...
Wu Xiang - - 2013
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 ...
Middleton Benita - - 2013
Melatonin is an indole hormone secreted by the pineal gland during the hours of darkness in a normally entrained individual. There is a clear circadian rhythm in its production with low levels during the day and a peak in the early hours of the morning. The timing of sample collection ...
O'Neill John S JS Department of Clinical Neurosciences, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, UK. - - 2013
Circadian clocks drive the daily rhythms in our physiology and behaviour that adapt us to the 24-h solar and social worlds. Because they impinge upon every facet of metabolism, their acute or chronic disruption compromises performance (both physical and mental) and systemic health, respectively. Equally, the presence of such rhythms ...
Sinam Boynao B Center for Biological Rhythm Research; Ahmednagar College; Ahmednagar, - - 2013
Jetlag results from the misalignment between the endogenous circadian timing and the civil timing after a transmeridian flight. Efficacy of the dim nocturnal illumination (0.03 lx) in accelerating the reentrainment following simulated jetlags in Drosophila biarmipes was examined by subjecting the flies to 24 h light-dark cycles in which the ...
Ruiz Santiago - - 2013
Previous studies have shown that the morphology of the neuromuscular junction of the flight motor neuron MN5 in Drosophila melanogaster undergoes daily rhythmical changes, with smaller synaptic boutons during the night, when the fly is resting, than during the day, when the fly is active. With electron microscopy and laser ...
Semple-Rowland Susan S Department of Neuroscience, University of Florida, Gainesville, Florida, United States of - - 2013
Many aspects of retinal photoreceptor function and physiology are regulated by the circadian clocks in these cells. It is well established that light is the primary stimulus that entrains these clocks; yet, the biochemical cascade(s) mediating light's effects on these clocks remains unknown. This deficiency represents a significant gap in ...
Volpato Gilson L - - 2013
Nile tilapia fish were individually reared under similar light levels for 8 weeks under five colored light spectra (maximum wavelength absorbance): white (full light spectrum), blue (∼452 nm), green (∼516 nm), yellow (∼520 nm) or red (∼628 nm). The effects of light on feeding, latency to begin feeding, growth and ...
Cullen Joshua A - - 2013
Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated ...
Verwey Michael - - 2013
When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day(1-5). Nocturnal rodents, including rats, hamsters, and mice, are active during the night and relatively inactive during the day. Many other behavioral and physiological measures also ...
Destici Eugin E Department of Genetics, Center for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The - - 2013
The mammalian circadian system is composed of a light-entrainable central clock in the suprachiasmatic nuclei (SCN) of the brain and peripheral clocks in virtually any other tissue. It allows the organism to optimally adjust metabolic, physiological and behavioral functions to the physiological needs it will have at specific time of ...
Martinez-Nicolas Antonio - - 2013
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 ...
Sorek Michal - - 2013
Biological clocks are self-sustained endogenous timers that enable organisms (from cyanobacteria to humans) to anticipate daily environmental rhythms, and adjust their physiology and behaviour accordingly. Symbiotic corals play a central role in the creation of biologically rich ecosystems based on mutualistic symbioses between the invertebrate coral and dinoflagellate protists from ...
Aramendy Marie M Department of Biology, Unit of Biochemistry, University of Fribourg, Fribourg, Switzerland. - - 2013
Mammals can adapt to changing light/dark conditions by advancing or delaying their circadian clock phase. Light pulses evoke changes in gene expression and neuronal activity in the suprachiasmatic nuclei (SCN), the central pacemaker of the circadian system. Alterations in neuronal activity are partially mediated by changes in synaptic vesicle (SV) ...
Emens Jonathan S - - 2013
To assess the interindividual and intraindividual variability in the circadian rhythms of blind individuals with non-24-h disorder and to quantify the influence of environmental time cues in blind subjects lacking entrainment (non-24-h individuals or N-24s). An observational study of 21 N-24s (11 females and 10 males, age 9-78 years) who ...
Soltész Fruzsina - - 2013
Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language), has been associated with behavioural entrainment deficits. It has ...
Chu Cheng - - 2013
The biochemical activity of mammals is controlled by an internal timekeeping mechanism driving a clock to run in approximate 24-hour (circadian) cycles. In mammals, this circadian clock is located both in the suprachiasmatic nuclei (SCN) and peripheral oscillators. Recently, microRNAs have emerged as significant players in circadian clock timing. The ...
Leman Marc - - 2013
Inspired by a theory of embodied music cognition, we investigate whether music can entrain the speed of beat synchronized walking. If human walking is in synchrony with the beat and all musical stimuli have the same duration and the same tempo, then differences in walking speed can only be the ...
Flôres Danilo E F L - - 2013
Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in environmental variables. Our observations of tuco-tucos (Ctenomys aff. knighti) in a field enclosure indicated that these animals perceive the aboveground light-dark cycle by several bouts of light-exposure at irregular times during the light ...
Brown Steven A - - 2013
Although circadian rhythms in mammalian physiology and behavior are dependent upon a biological clock in the suprachiasmatic nuclei (SCN) of the hypothalamus, the molecular mechanism of this clock is in fact cell autonomous and conserved in nearly all cells of the body. Thus, the SCN serves in part as a ...
Bordyugov G - - 2013
Circadian clocks are autonomous oscillators entrained by external Zeitgebers such as light-dark and temperature cycles. On the cellular level, rhythms are generated by negative transcriptional feedback loops. In mammals, the suprachiasmatic nucleus (SCN) in the anterior part of the hypothalamus plays the role of the central circadian pacemaker. Coupling between ...
Zoefel Benedikt - - 2013
Low-frequency oscillations in the electroencephalogram (EEG) are thought to reflect periodic excitability changes of large neural networks. Consistent with this notion, detection probability of near-threshold somatosensory, visual, and auditory targets has been reported to co-vary with the phase of oscillations in the EEG. In audition, entrainment of δ-oscillations to the ...
Challet Etienne - - 2013
Circadian rhythmicity that has been shaped by evolution over millions of years generates an internal timing controlling the sleep-wake and metabolism cycles. The daily variations between sleep/fasting/catabolism and wakefulness/feeding/anabolism are coordinated by a master hypothalamic clock, mainly reset by ambient light. Secondary clocks, including liver and adipose tissue, are normally ...
Goldbogen Jeremy A - - 2013
Mid-frequency military (1-10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera ...
Haeri Mohammad - - 2013
The rod outer segment (OS), comprised of tightly stacked disk membranes packed with rhodopsin, is in a dynamic equilibrium governed by a diurnal rhythm with newly synthesized membrane inserted at the OS base balancing membrane loss from the distal tip via disk shedding. Using transgenic Xenopus and live cell confocal ...
Kim J K JK Department of Mathematics, University of Michigan, Ann Arbor, Michigan, - - 2013
Circadian rhythms can be entrained by a light-dark (LD) cycle and can also be reset pharmacologically, for example, by the CK1δ/ε inhibitor PF-670462. Here, we determine how these two independent signals affect circadian timekeeping from the molecular to the behavioral level. By developing a systems pharmacology model, we predict and ...
Gin Elan E Division of Theoretical Systems Biology, German Cancer Research Center-DKFZ, Heidelberg, - - 2013
The light response in Neurospora is mediated by the photoreceptor and circadian transcription factor White Collar Complex (WCC). The expression rate of the WCC target genes adapts in daylight and remains refractory to moonlight, despite the extraordinary light sensitivity of the WCC. To explain this photoadaptation, feedback inhibition by the ...
Wood Nigel I - - 2013
The R6/2 transgenic mouse model of Huntington's disease (HD) shows a disintegration of circadian rhythms that can be delayed by pharmacological and non-pharmacological means. Since the molecular machinery underlying the circadian clocks is intact, albeit progressively dysfunctional, we wondered if light phase shifts could modulate the deterioration in daily rhythms ...
Patton Danica F - - 2013
Restricted daily feeding schedules entrain circadian oscillators that generate food anticipatory activity (FAA) rhythms in nocturnal rodents. The location of food-entrainable oscillators (FEOs) necessary for FAA remains uncertain. The most common procedure for inducing circadian FAA is to limit food access to a few hours in the middle of the ...
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