Do changes in subjective sleep and biological rhythms predict worsening in postpartum depressive symptoms? A prospective study across the perinatal period.

PubMed

Krawczak, Elizabeth M; Minuzzi, Luciano; Hidalgo, Maria Paz; Frey, Benicio N

2016-08-01

Abnormalities of sleep and biological rhythms have been widely implicated in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD). However, less is known about the influence of biological rhythm disruptions across the perinatal period on postpartum depression (PPD). The objective of this study was to prospectively evaluate the relationship between subjective changes in both sleep and biological rhythms and worsening of depressive symptoms from pregnancy to the postpartum period in women with and without mood disorders. Eighty-three participants (38 euthymic women with a history of a mood disorder and 45 healthy controls) were studied. Participants completed subjective assessments of sleep (Pittsburgh Sleep Quality Index), biological rhythm disturbances (Biological Rhythms Interview of Assessment in Neuropsychiatry), and depressive symptoms (Edinburgh Postnatal Depression Scale) prospectively at two time points: third trimester of pregnancy and at 6-12 weeks postpartum. Multivariate regression analyses showed that changes in biological rhythms across the perinatal period predicted worsening of depressive symptoms in both groups. Moreover, women with a history of a mood disorder showed higher levels of sleep and biological rhythm disruption during both pregnancy and the postpartum period. These findings suggest that disruptions in biological rhythms during the perinatal period increase the risk for postpartum mood worsening in healthy pregnant as well as in pregnant women with a history of mood disorders.

Adaptation of sleep and circadian rhythms to the Antarctic summer - A question of zeitgeber strength

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Macdonald, John A.; Montgomery, John C.; Paulin, Michael G.

1991-01-01

Adaptation of sleep and circadian rhythms was examined in three temperate zone dwellers arriving in Antarctica during summer. Rectal temperature, wrist activity, and heart rate were monitored continuously, sleep timing and quality noted on awakening, and mood and fatigue rated every 2 h while awake. Sleep was poorer in 2/3 subjects in Antarctica, where all subjects reported more difficulty rising. Sleep occurred at the same clock times in New Zealand and Antarctica, however, the rhythms of temperature, activity, and heart rate underwent a delay of about of 2 h. The subject with the most Antarctic experience had the least difficulty adapting to sleeping during constant daylight. The subject with the most delayed circadian rhythms had the most difficulty. The delay in the circadian system with respect to sleep and clock time is hypothesized to be due to differences in zeitgeber strength and/or zeitgeber exposure between Antarctica and New Zealand.

Chorusing, synchrony, and the evolutionary functions of rhythm

PubMed Central

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

Chorusing, synchrony, and the evolutionary functions of rhythm.

PubMed

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

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

PubMed

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.

Society for Research on Biological Rhythms (1st) Held on May 11-14, 1988 in Charleston, South Carolina

DTIC Science & Technology

1988-08-10

and applied research in all aspects of biological 8:00 a.m. to 1:00 p.m., May 12-14 and from 4:30 - 6 :30 rhythms , to disseminate important research...NUCLEUS (SCN) NEU- RONS IN VITRO WITHOUT ALTERING THE GLUCOSE Workshop 6 : UTILIZATION RHYTHM OR PHASE OF THE RHYTHM Involvement of Protein Synthesis in...Medical Science, Seta-Tsukinowa, Otsu- city, Shiga, Japan. Circadian Rhythms 74 RUNNING WHEEL AVAILABILITY ENTRAINS SLEEP- 65 PHASE RESPONSE CURVES AS

Biological rhythms: the taste-time continuum.

PubMed

Krupp, Joshua J; Levine, Joel D

2010-02-23

The gustatory system allows the fly to assess food quality, eliciting either acceptance or avoidance behaviors. A new study demonstrates that circadian clocks in gustatory receptor neurons regulate rhythms in taste sensitivity, drive rhythms in appetitive behavior and influence feeding. Copyright 2010 Elsevier Ltd. All rights reserved.

[Alteration of biological rhythms causes metabolic diseases and obesity].

PubMed

Saderi, Nadia; Escobar, Carolina; Salgado-Delgado, Roberto

2013-07-16

The incidence of obesity worldwide has become a serious, constantly growing public health issue that reaches alarming proportions in some countries. To date none of the strategies developed to combat obesity have proved to be decisive, and hence there is an urgent need to address the problem with new approaches. Today, studies in the field of chronobiology have shown that our physiology continually adapts itself to the cyclical changes in the environment, regard-less of whether they are daily or seasonal. This is possible thanks to the existence of a biological clock in our hypothalamus which regulates the expression and/or activity of enzymes and hormones involved in regulating our metabolism, as well as all the homeostatic functions. It has been observed that this clock can be upset as a result of today's modern lifestyle, which involves a drop in physical activity during the day and the abundant ingestion of food during the night, among other factors, which together promote metabolic syndrome and obesity. Hence, the aim of this review is to summarise the recent findings that show the effect that altering the circadian rhythms has on the metabolism and how this can play a part in the development of metabolic diseases.

Air Travel, Circadian Rhythms/Hormones, and Autoimmunity.

PubMed

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.

Ethics and methods for biological rhythm research on animals and human beings.

PubMed

Portaluppi, Francesco; Smolensky, Michael H; Touitou, Yvan

2010-10-01

This article updates the ethical standards and methods for the conduct of high-quality animal and human biological rhythm research, which should be especially useful for new investigators of the rhythms of life. The editors of Chronobiology International adhere to and endorse the Code of Conduct and Best Practice Guidelines of the Committee On Publication Ethics (COPE), which encourages communication of such updates at regular intervals in the journal. The journal accepts papers representing original work, no part of which was previously submitted for publication elsewhere, except as brief abstracts, as well as in-depth reviews. The majority of research papers published in Chronobiology International entails animal and human investigations. The editors and readers of the journal expect authors of submitted manuscripts to have made an important contribution to the research of biological rhythms and related phenomena using ethical methods/procedures and unbiased, accurate, and honest reporting of findings. Authors of scientific papers are required to declare all potential conflicts of interest. The journal and its editors endorse compliance of investigators to the Guide for the Care and Use of Laboratory Animals of the Institute for Laboratory Animal Research of the National Research Council, relating to the conduct of ethical research on laboratory and other animals, and the principles of the Declaration of Helsinki of the World Medical Association, relating to the conduct of ethical research on human beings. The peer review of manuscripts by Chronobiology International thus includes judgment as to whether or not the protocols and methods conform to ethical standards. Authors are expected to show mastery of the basic methods and procedures of biological rhythm research and proper statistical assessment of data, including the appropriate application of time series data analyses, as briefly reviewed in this article. The journal editors strive to consistently achieve

Rhythms in the endocrine system of fish: a review.

PubMed

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.

Ethical and methodological standards for laboratory and medical biological rhythm research.

PubMed

Portaluppi, Francesco; Touitou, Yvan; Smolensky, Michael H

2008-11-01

The main objectives of this article are to update the ethical standards for the conduct of human and animal biological rhythm research and recommend essential elements for quality chronobiological research information, which should be especially useful for new investigators of the rhythms of life. A secondary objective is to provide for those with an interest in the results of chronobiology investigations, but who might be unfamiliar with the field, an introduction to the basic methods and standards of biological rhythm research and time series data analysis. The journal and its editors endorse compliance of all investigators to the principles of the Declaration of Helsinki of the World Medical Association, which relate to the conduct of ethical research on human beings, and the Guide for the Care and Use of Laboratory Animals of the Institute for Laboratory Animal Research of the National Research Council, which relate to the conduct of ethical research on laboratory and other animals. The editors and the readers of the journal expect the authors of submitted manuscripts to have adhered to the ethical standards dictated by local, national, and international laws and regulations in the conduct of investigations and to be unbiased and accurate in reporting never-before-published research findings. Authors of scientific papers are required to disclose all potential conflicts of interest, particularly when the research is funded in part or in full by the medical and pharmaceutical industry, when the authors are stock-holders of the company that manufactures or markets the products under study, or when the authors are a recent or current paid consultant to the involved company. It is the responsibility of the authors of submitted manuscripts to clearly present sufficient detail about the synchronizer schedule of the studied subjects (i.e., the sleep-wake schedule, ambient light-dark cycle, intensity and spectrum of ambient light exposure, seasons when the research was

Circadian Rhythms in Cyanobacteria

PubMed Central

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

Circadian rhythm adaptation to simulated night shift work: effect of nocturnal bright-light duration.

PubMed

Eastman, C I; Liu, L; Fogg, L F

1995-07-01

We compared bright-light durations of 6, 3 and 0 hours (i.e. dim light) during simulated night shifts for phase shifting the circadian rectal temperature rhythm to align with a 12-hour shift of the sleep schedule. After 10 baseline days there were 8 consecutive night-work, day-sleep days, with 8-hour sleep (dark) periods. The bright light (about 5,000 lux, around the baseline temperature minimum) was used during all 8 night shifts, and dim light was < 500 lux. This was a field study in which subjects (n = 46) went outside after the night shifts and slept at home. Substantial circadian adaptation (i.e. a large cumulative temperature rhythm phase shift) was produced in many subjects in the bright light groups, but not in the dim light group. Six and 3 hours of bright light were each significantly better than dim light for phase shifting the temperature rhythm, but there was no significant difference between 6 and 3 hours. Thus, durations > 3 hours are probably not necessary in similar shift-work situations. Larger temperature rhythm phase shifts were associated with better subjective daytime sleep, less subjective fatigue and better overall mood.

The study of synchronization of rhythms of microvascular blood flow and oxygen saturation during adaptive changes

NASA Astrophysics Data System (ADS)

Dunaev, Andrey V.; Sidorov, Victor V.; Krupatkin, Alexander I.; Rafailov, Ilya E.; Palmer, Scott G.; Sokolovski, Sergei G.; Stewart, Neil A.; Rafailov, Edik U.

2014-02-01

Multi-functional laser non-invasive diagnostic systems, such as "LAKK-M", allow the study of a number of microcirculatory parameters, including blood microcirculatory index (Im) (by laser Doppler flowmetry, LDF) and oxygen saturation (StO2) of skin tissue (by tissue reflectance oximetry, TRO). Such systems may provide significant information relevant to physiology and clinical medicine. The aim of this research was to use such a system to study the synchronization of microvascular blood flow and oxygen saturation rhythms under normal and adaptive change conditions. Studies were conducted with 8 healthy volunteers - 3 females and 5 males of 21-49 years. Each volunteer was subjected to basic 3 minute tests. The volunteers were observed for between 1-4 months each, totalling 422 basic tests. Measurements were performed on the palmar surface of the right middle finger and the forearm medial surface. Wavelet analysis was used to study rhythmic oscillations in LDF- and TRO-data. Tissue oxygen consumption (from arterial and venal blood oxygen saturation and nutritive flux volume) was calculated for all volunteers during "adaptive changes" as (617+/-123 AU) and (102+/-38 AU) with and without arteriovenous anastomoses (AVAs) respectively. This demonstrates increased consumption compared to normal (495+/-170 AU) and (69+/-40 AU) with and without AVAs respectively. Data analysis demonstrated the emergence of resonance and synchronization of rhythms of microvascular blood flow and oxygen saturation as an adaptive change in myogenic oscillation (vasomotion) resulting from exercise and potentially from psychoemotional stress. Synchronization of myogenic rhythms during adaptive changes suggest increased oxygen consumption resulting from increased microvascular blood flow velocity.

Design and analysis of large-scale biological rhythm studies: a comparison of algorithms for detecting periodic signals in biological data

PubMed Central

Deckard, Anastasia; Anafi, Ron C.; Hogenesch, John B.; Haase, Steven B.; Harer, John

2013-01-01

Motivation: To discover and study periodic processes in biological systems, we sought to identify periodic patterns in their gene expression data. We surveyed a large number of available methods for identifying periodicity in time series data and chose representatives of different mathematical perspectives that performed well on both synthetic data and biological data. Synthetic data were used to evaluate how each algorithm responds to different curve shapes, periods, phase shifts, noise levels and sampling rates. The biological datasets we tested represent a variety of periodic processes from different organisms, including the cell cycle and metabolic cycle in Saccharomyces cerevisiae, circadian rhythms in Mus musculus and the root clock in Arabidopsis thaliana. Results: From these results, we discovered that each algorithm had different strengths. Based on our findings, we make recommendations for selecting and applying these methods depending on the nature of the data and the periodic patterns of interest. Additionally, these results can also be used to inform the design of large-scale biological rhythm experiments so that the resulting data can be used with these algorithms to detect periodic signals more effectively. Contact: anastasia.deckard@duke.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24058056

Biological Rhythms in the Skin

PubMed Central

Matsui, Mary S.; Pelle, Edward; Dong, Kelly; Pernodet, Nadine

2016-01-01

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. PMID:27231897

Children with developmental coordination disorder (DCD) can adapt to perceptible and subliminal rhythm changes but are more variable.

PubMed

Roche, Renuka; Viswanathan, Priya; Clark, Jane E; Whitall, Jill

2016-12-01

Children with DCD demonstrate impairments in bimanual finger tapping during self-paced tapping and tapping in synchrony to different frequencies. In this study, we investigated the ability of children with DCD to adapt motorically to perceptible or subliminal changes of the auditory stimuli without a change in frequency, and compared their performance to typically developing controls (TDC). Nineteen children with DCD between ages 6-11years (mean age±SD=114±21months) and 17 TDC (mean age±SD=113±21months) participated in this study. Auditory perceptual threshold was established. Children initially tapped bimanually to an antiphase beat and then to either a perceptible change in rhythm or to gradual subliminal changes in rhythm. Children with DCD were able to perceive changes in rhythm similar to TDC. They were also able to adapt to both perceptible and subliminal changes in rhythms similar to their age- and gender- matched TDC. However, these children were significantly more variable compared with TDC in all phasing conditions. The results suggest that the performance impairments in bilateral tapping are not a result of poor conscious or sub-conscious perception of the auditory cue. The increased motor variability may be associated with cerebellar dysfunction but further behavioral and neurophysiological studies are needed. Copyright © 2016 Elsevier B.V. All rights reserved.

Amelioration of psychiatric symptoms through exposure to music individually adapted to brain rhythm disorders - a randomised clinical trial on the basis of fundamental research.

PubMed

Müller, Wolf; Haffelder, Günter; Schlotmann, Angelika; Schaefers, Andrea T U; Teuchert-Noodt, Gertraud

2014-01-01

This pilot study examined, whether long-term exposure of psychiatric patients to music that was individually adapted to brain rhythm disorders associated with psychoticism could act to ameliorate psychiatric symptoms. A total of 50 patients with various psychiatric diagnoses were randomised in a 1:1 ratio to listen to CDs containing either music adapted to brain rhythm anomalies associated with psychoticism - measured via a specific spectral analysis - or standard classical music. Participants were instructed to listen to the CDs over the next 18 months. Psychiatric symptoms in both groups were assessed at baseline and at 4, 8 and 18 months, using the Brief Symptom Inventory (BSI). At 18 months, patients in the experimental group showed significantly decreased BSI scores compared to control patients. Intriguingly, this effect was not only seen for symptoms of psychoticism and paranoia but also for anxiety, phobic anxiety and somatisation. Exposure to the adapted music was effective in ameliorating psychotic, anxiety and phobic anxiety symptoms. Based on the theories of neuroplasticity and brain rhythms, it can be hypothesised that this intervention may be enhancing brain-rhythm synchronisation and plasticity in prefrontal-hippocampal circuits that are implicated in both psychosis/paranoia and anxiety/phobic anxiety.

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

PubMed

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.

Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value

PubMed Central

Bloch, Guy; Barnes, Brian M.; Gerkema, Menno P.; Helm, Barbara

2013-01-01

Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles. PMID:23825202

Characterisation of circadian rhythms of various duckweeds.

PubMed

Muranaka, T; Okada, M; Yomo, J; Kubota, S; Oyama, T

2015-01-01

The plant circadian clock controls various physiological phenomena that are important for adaptation to natural day-night cycles. Many components of the circadian clock have been identified in Arabidopsis thaliana, the model plant for molecular genetic studies. Recent studies revealed evolutionary conservation of clock components in green plants. Homologues of clock-related genes have been isolated from Lemna gibba and Lemna aequinoctialis, and it has been demonstrated that these homologues function in the clock system in a manner similar to their functioning in Arabidopsis. While clock components are widely conserved, circadian phenomena display diversity even within the Lemna genus. In order to survey the full extent of diversity in circadian rhythms among duckweed plants, we characterised the circadian rhythms of duckweed by employing a semi-transient bioluminescent reporter system. Using a particle bombardment method, circadian bioluminescent reporters were introduced into nine strains representing five duckweed species: Spirodela polyrhiza, Landoltia punctata, Lemna gibba, L. aequinoctialis and Wolffia columbiana. We then monitored luciferase (luc+) reporter activities driven by AtCCA1, ZmUBQ1 or CaMV35S promoters under entrainment and free-running conditions. Under entrainment, AtCCA1::luc+ showed similar diurnal rhythms in all strains. This suggests that the mechanism of biological timing under day-night cycles is conserved throughout the evolution of duckweeds. Under free-running conditions, we observed circadian rhythms of AtCCA1::luc+, ZmUBQ1::luc+ and CaMV35S::luc+. These circadian rhythms showed diversity in period length and sustainability, suggesting that circadian clock mechanisms are somewhat diversified among duckweeds. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

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

PubMed

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.

Suicide attempts in children and adolescents: The place of clock genes and early rhythm dysfunction.

PubMed

Olliac, Bertrand; Ouss, Lisa; Charrier, Annaëlle

2016-11-01

Suicide remains one of the leading causes of death among young people, and suicidal ideation and behavior are relatively common in healthy and clinical populations. Suicide risk in childhood and adolescence is often approached from the perspective of nosographic categories to which predictive variables for suicidal acts are often linked. The cascading effects resulting from altered clock genes in a pediatric population could participate in biological rhythm abnormalities and the emergence of suicide attempts through impaired regulation of circadian rhythms and emotional states with neurodevelopmental effects. Also, early trauma and stressful life events can alter the expression of clock genes and contribute to the emergence of suicide attempts. Alteration of clock genes might lead to desynchronized and abnormal circadian rhythms impairing in turn the synchronization between external and internal rhythms and therefore the adaptation of the individual to his/her internal and external environment with the development of psychiatric disorders associated with increased risk for suicide attempts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Circadian Rhythm Sleep Disorders

PubMed Central

Zhu, Lirong; Zee, Phyllis C.

2012-01-01

There have been remarkable advances in our understanding of the molecular, cellular and physiological mechanisms underlying the regulation of circadian rhythms, as well as the impact of circadian dysfunction on health and disease. This information has transformed our understanding of the effect of circadian rhythm sleep disorders (CRSD) on health, performance and safety. CRSDs are caused by alterations of the central circadian time-keeping system, or a misalignment of the endogenous circadian rhythm and the external environment. In this section, we provide a review of circadian biology and discuss the pathophysiology, clinical features, diagnosis, and treatment of the most commonly encountered CRSDs in clinical practice. PMID:23099133

Biological Rhythms During Residence in Polar Regions

PubMed Central

2012-01-01

At Arctic and Antarctic latitudes, personnel are deprived of natural sunlight in winter and have continuous daylight in summer: light of sufficient intensity and suitable spectral composition is the main factor that maintains the 24-h period of human circadian rhythms. Thus, the status of the circadian system is of interest. Moreover, the relatively controlled artificial light conditions in winter are conducive to experimentation with different types of light treatment. The hormone melatonin and/or its metabolite 6-sulfatoxymelatonin (aMT6s) provide probably the best index of circadian (and seasonal) timing. A frequent observation has been a delay of the circadian system in winter. A skeleton photoperiod (2 × 1-h, bright white light, morning and evening) can restore summer timing. A single 1-h pulse of light in the morning may be sufficient. A few people desynchronize from the 24-h day (free-run) and show their intrinsic circadian period, usually >24 h. With regard to general health in polar regions, intermittent reports describe abnormalities in various physiological processes from the point of view of daily and seasonal rhythms, but positive health outcomes are also published. True winter depression (SAD) appears to be rare, although subsyndromal SAD is reported. Probably of most concern are the numerous reports of sleep problems. These have prompted investigations of the underlying mechanisms and treatment interventions. A delay of the circadian system with “normal” working hours implies sleep is attempted at a suboptimal phase. Decrements in sleep efficiency, latency, duration, and quality are also seen in winter. Increasing the intensity of ambient light exposure throughout the day advanced circadian phase and was associated with benefits for sleep: blue-enriched light was slightly more effective than standard white light. Effects on performance remain to be fully investigated. At 75°S, base personnel adapt the circadian system to night work within

Adaptive filtering in biological signal processing.

PubMed

Iyer, V K; Ploysongsang, Y; Ramamoorthy, P A

1990-01-01

The high dependence of conventional optimal filtering methods on the a priori knowledge of the signal and noise statistics render them ineffective in dealing with signals whose statistics cannot be predetermined accurately. Adaptive filtering methods offer a better alternative, since the a priori knowledge of statistics is less critical, real time processing is possible, and the computations are less expensive for this approach. Adaptive filtering methods compute the filter coefficients "on-line", converging to the optimal values in the least-mean square (LMS) error sense. Adaptive filtering is therefore apt for dealing with the "unknown" statistics situation and has been applied extensively in areas like communication, speech, radar, sonar, seismology, and biological signal processing and analysis for channel equalization, interference and echo canceling, line enhancement, signal detection, system identification, spectral analysis, beamforming, modeling, control, etc. In this review article adaptive filtering in the context of biological signals is reviewed. An intuitive approach to the underlying theory of adaptive filters and its applicability are presented. Applications of the principles in biological signal processing are discussed in a manner that brings out the key ideas involved. Current and potential future directions in adaptive biological signal processing are also discussed.

Another place, another timer: Marine species and the rhythms of life

PubMed Central

Tessmar-Raible, Kristin; Raible, Florian; Arboleda, Enrique

2011-01-01

The marine ecosystem is governed by a multitude of environmental cycles, all of which are linked to the periodical recurrence of the sun or the moon. In accordance with these cycles, marine species exhibit a variety of biological rhythms, ranging from circadian and circatidal rhythms to circalunar and seasonal rhythms. However, our current molecular understanding of biological rhythms and clocks is largely restricted to solar-controlled circadian and seasonal rhythms in land model species. Here, we discuss the first molecular data emerging for circalunar and circatidal rhythms and present selected species suitable for further molecular analyses. We argue that a re-focus on marine species will be crucial to understand the principles, interactions and evolution of rhythms that govern a broad range of eukaryotes, including ourselves. PMID:21254149

The Scorpion An ideal animal model to study long-term microgravity effects on circadian rhythms

NASA Astrophysics Data System (ADS)

Riewe, Pascal C.; Horn, Eberhard R.

2000-01-01

The temporal pattern of light and darkness is basic for the coordination of circadian rhythms and establishment of homoeostasis. The 24th frequency of zeitgebers is probably a function of the Earth's rotation. The only way to eliminate its influence on organisms is to study their behavior in space because the reduced day length during orbiting the Earth might disrupt synchronizing mechanisms based on the 24th rhythm. The stability of microgravity induced disturbances of synchronization as well as the extent of adaptation of different physiological processes to this novel environment can only be studied during long-term exposures to microgravity, i.e., on the International Space Station. Biological studies within the long-term domain on ISS demand the use of experimental models which can be exposed to automatic handling of measurements and which need less or no nutritional care. Scorpions offer these features. We describe a fully automatic recording device for the simultaneous collection of data regarding the sensorimotor system and homoeostatic mechanisms. In particular, we record sensitivity changes of the eyes, motor activity and heart beat and/or respiratory activity. The advantage of the scorpion model is supported by the fact that data can be recorded preflight, inflight and postflight from the same animal. With this animal model, basic insights will be obtained about the de-coupling of circadian rhythms of multiple oscillators and their adaptation to the entraining zeitgeber periodicity during exposure to microgravity for at least three biological parameters recorded simultaneously. .

Spontaneous circadian rhythms in a cold-adapted natural isolate of Aureobasidium pullulans.

PubMed

Franco, Diana L; Canessa, Paulo; Bellora, Nicolás; Risau-Gusman, Sebastián; Olivares-Yañez, Consuelo; Pérez-Lara, Rodrigo; Libkind, Diego; Larrondo, Luis F; Marpegan, Luciano

2017-10-23

Circadian systems enable organisms to synchronize their physiology to daily and seasonal environmental changes relying on endogenous pacemakers that oscillate with a period close to 24 h even in the absence of external timing cues. The oscillations are achieved by intracellular transcriptional/translational feedback loops thoroughly characterized for many organisms, but still little is known about the presence and characteristics of circadian clocks in fungi other than Neurospora crassa. We sought to characterize the circadian system of a natural isolate of Aureobasidium pullulans, a cold-adapted yeast bearing great biotechnological potential. A. pullulans formed daily concentric rings that were synchronized by light/dark cycles and were also formed in constant darkness with a period of 24.5 h. Moreover, these rhythms were temperature compensated, as evidenced by experiments conducted at temperatures as low as 10 °C. Finally, the expression of clock-essential genes, frequency, white collar-1, white collar-2 and vivid was confirmed. In summary, our results indicate the existence of a functional circadian clock in A. pullulans, capable of sustaining rhythms at very low temperatures and, based on the presence of conserved clock-gene homologues, suggest a molecular and functional relationship to well-described circadian systems.

Rhythm perturbations in acoustically paced treadmill walking after stroke.

PubMed

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 rhythms and the effects of long-distance flights.

DOT National Transportation Integrated Search

1968-01-01

Air travelers crossing four or more time zones experience significant desynchronization of certain daily biologic rhythms. Until rephasing of the rhythms occurs relative to the solar cycle at the destination, some subjective discomfort and disruption...

[Individual peculiarities of adaptation to long-term space flights: 24-hour heart rhythm monitoring

NASA Technical Reports Server (NTRS)

Baevskii, R. M.; Bogomolov, V. V.; Gol'dberger, A. L.; Nikulina, G. A.; Charl'z, D. B.; Goldberger, A. L. (Principal Investigator); Charles, J. B. (Principal Investigator)

2000-01-01

Presented are results of studying 24-hr variability of the cardiac rhythm which characterizes individual difference in reactions of two crew members to the same set of stresses during a 115-day MIR mission. Spacelab (USA) cardiorecorders were used. Data of monitoring revealed significantly different baseline health statuses of the cosmonauts. These functional differences were also observed in the mission. In one of the cosmonauts, the cardiac regulation changed over to a more economic functioning with the autonomous balance shifted towards enhanced sympathetic activity. After 2-3 months on mission he had almost recovered pre-launch level of regulation. In the other, the regulatory system was appreciably strained at the beginning of the mission as compared with preflight baseline. Later on, on flight months 2-3, this strain kept growing till a drastic depletion of the functional reserve. On return to Earth, this was manifested by a strong stress reaction with a sharp decline in power of high-frequency and grow in power of very low frequency components of the heart rhythm. The data suggest that adaptation to space flight and reactions in the readaptation period are dependent on initial health status of crew members, and functional reserve.

Studying Biological Rhythms of Person's Skin-galvanic Reaction and Dynamics of Light Transmission by Isomeric Substance in Space Flight Conditions

NASA Technical Reports Server (NTRS)

Glushko, Vladimir

2004-01-01

Intensity and amplitude of human functional systems and human most important organs are wavelike, rhythmic by nature. These waves have constant periodicity, phase and amplitude. The mentioned characteristics can vary, however their variations have a pronounced reiteration in the course of time. This indicates a hashing of several wave processes and their interference. Stochastic changes in wave processes characteristics of a human organism are explained either by 'pulsations' associated with hashing (superposition) of several wave processes and their interference, or by single influence of environmental physical factors on a human organism. Human beings have respectively periods of higher and lower efficiency, state of health and so on, depending not only of environmental factors, but also of 'internal' rhythmic factor. Sometimes peaks and falls periodicity of some or other characteristics is broken. Disturbance of steady-state biological rhythms is usually accompanied by reduction of activity steadiness of the most important systems of a human organism. In its turn this has an effect on organism's adaptation to changing living conditions as well as on general condition and efficiency of a human being. The latter factor is very important for space medicine. Biological rhythmology is a special branch of biology and medicine, it studies rhythmic activity mechanisms of organs, their systems, individuals and species. Appropriate researches were also carried out in space medicine.

An Overview of Monthly Rhythms and Clocks

PubMed Central

Raible, Florian; Takekata, Hiroki; Tessmar-Raible, Kristin

2017-01-01

Organisms have evolved to cope with geophysical cycles of different period lengths. In this review, we focus on the adaptations of animals to the lunar cycle, specifically, on the occurrence of biological rhythms with monthly (circalunar) or semi-monthly (circasemilunar) period lengths. Systematic experimental investigation, starting in the early twentieth century, has allowed scientists to distinguish between mythological belief and scientific facts concerning the influence of the lunar cycle on animals. These studies revealed that marine animals of various taxa exhibit circalunar or circasemilunar reproductive rhythms. Some of these rely on endogenous oscillators (circalunar or circasemilunar clocks), whereas others are directly driven by external cues, such as the changes in nocturnal illuminance. We review current insight in the molecular and cellular mechanisms involved in circalunar rhythms, focusing on recent work in corals, annelid worms, midges, and fishes. In several of these model systems, the transcript levels of some core circadian clock genes are affected by both light and endogenous circalunar oscillations. How these and other molecular changes relate to the changes in physiology or behavior over the lunar cycle remains to be determined. We further review the possible relevance of circalunar rhythms for terrestrial species, with a particular focus on mammalian reproduction. Studies on circalunar rhythms of conception or birth rates extend to humans, where the lunar cycle was suggested to also affect sleep and mental health. While these reports remain controversial, factors like the increase in “light pollution” by artificial light might contribute to discrepancies between studies. We finally discuss the existence of circalunar oscillations in mammalian physiology. We speculate that these oscillations could be the remnant of ancient circalunar oscillators that were secondarily uncoupled from a natural entrainment mechanism, but still maintained

Detecting Rhythms in Time Series with RAIN

PubMed Central

Thaben, Paul F.; Westermark, Pål O.

2014-01-01

A fundamental problem in research on biological rhythms is that of detecting and assessing the significance of rhythms in large sets of data. Classic methods based on Fourier theory are often hampered by the complex and unpredictable characteristics of experimental and biological noise. Robust nonparametric methods are available but are limited to specific wave forms. We present RAIN, a robust nonparametric method for the detection of rhythms of prespecified periods in biological data that can detect arbitrary wave forms. When applied to measurements of the circadian transcriptome and proteome of mouse liver, the sets of transcripts and proteins with rhythmic abundances were significantly expanded due to the increased detection power, when we controlled for false discovery. Validation against independent data confirmed the quality of these results. The large expansion of the circadian mouse liver transcriptomes and proteomes reflected the prevalence of nonsymmetric wave forms and led to new conclusions about function. RAIN was implemented as a freely available software package for R/Bioconductor and is presently also available as a web interface. PMID:25326247

Circadian Rhythm Disruption Promotes Lung Tumorigenesis.

PubMed

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.

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

PubMed Central

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

2016-01-01

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. PMID:27104378

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

PubMed

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.

Detecting phase-amplitude coupling with high frequency resolution using adaptive decompositions

PubMed Central

Pittman-Polletta, Benjamin; Hsieh, Wan-Hsin; Kaur, Satvinder; Lo, Men-Tzung; Hu, Kun

2014-01-01

Background Phase-amplitude coupling (PAC) – the dependence of the amplitude of one rhythm on the phase of another, lower-frequency rhythm – has recently been used to illuminate cross-frequency coordination in neurophysiological activity. An essential step in measuring PAC is decomposing data to obtain rhythmic components of interest. Current methods of PAC assessment employ narrowband Fourier-based filters, which assume that biological rhythms are stationary, harmonic oscillations. However, biological signals frequently contain irregular and nonstationary features, which may contaminate rhythms of interest and complicate comodulogram interpretation, especially when frequency resolution is limited by short data segments. New method To better account for nonstationarities while maintaining sharp frequency resolution in PAC measurement, even for short data segments, we introduce a new method of PAC assessment which utilizes adaptive and more generally broadband decomposition techniques – such as the empirical mode decomposition (EMD). To obtain high frequency resolution PAC measurements, our method distributes the PAC associated with pairs of broadband oscillations over frequency space according to the time-local frequencies of these oscillations. Comparison with existing methods We compare our novel adaptive approach to a narrowband comodulogram approach on a variety of simulated signals of short duration, studying systematically how different types of nonstationarities affect these methods, as well as on EEG data. Conclusions Our results show: (1) narrowband filtering can lead to poor PAC frequency resolution, and inaccuracy and false negatives in PAC assessment; (2) our adaptive approach attains better PAC frequency resolution and is more resistant to nonstationarities and artifacts than traditional comodulograms. PMID:24452055

Biological and environmental rhythms in (dark) deep-sea hydrothermal ecosystems

NASA Astrophysics Data System (ADS)

Cuvelier, Daphne; Legendre, Pierre; Laës-Huon, Agathe; Sarradin, Pierre-Marie; Sarrazin, Jozée

2017-06-01

During 2011, two deep-sea observatories focusing on hydrothermal vent ecology were up and running in the Atlantic (Eiffel Tower, Lucky Strike vent field) and the Northeast Pacific Ocean (NEP) (Grotto, Main Endeavour Field). Both ecological modules recorded imagery and environmental variables jointly for a time span of 23 days (7-30 October 2011) and environmental variables for up to 9 months (October 2011-June 2012). Community dynamics were assessed based on imagery analysis and rhythms in temporal variation for both fauna and environment were revealed. Tidal rhythms were found to be at play in the two settings and were most visible in temperature and tubeworm appearances (at NEP). A ˜ 6 h lag in tidal rhythm occurrence was observed between Pacific and Atlantic hydrothermal vents, which corresponds to the geographical distance and time delay between the two sites.

[Interpersonal and social rhythm therapy (IPSRT)].

PubMed

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

Environmental factors influencing biological rhythms in newborns: From neonatal intensive care units to home.

PubMed

Bueno, Clarissa; Menna-Barreto, Luiz

2016-01-01

Photic and non-photic environmental factors are suggested to modulate the development of circadian rhythms in infants. Our aim is to evaluate the development of biological rhythms (circadian or ultradian) in newborns in transition from Neonatal Intensive Care Units (NICU) to home and along the first 6 months of life, to identify masking and entraining environment factors along development. Ten newborns were evaluated in their last week inside the NICU and in the first week after being delivered home; 6 babies were also followed until 6 months of corrected age. Activity, recorded with actimeters, wrist temperature and observed sleep and feeding behavior were recorded continuously along their last week inside the NICU and in the first week at home and also until 6 months of corrected age for the subjects who remained in the study. Sleep/wake and activity/rest cycle showed ultradian patterns and the sleep/wake was strongly influenced by the 3 h feeding schedule inside the NICU, while wrist temperature showed a circadian pattern that seemed no to be affected by environmental cycles. A circadian rhythm emerges for sleep/wake behavior in the first week at home, whereas the 3 h period vanishes. Both activity/rest and wrist temperature presented a sudden increase in the contribution of the circadian component immediately after babies were delivered home, also suggesting a masking effect of the NICU environment. We found a positive correlation of postconceptional age and the increase in the daily component of activity and temperature along the following 6 months, while feeding behavior became arrhythmic.

Biological Rhythms Modelisation of Vigilance and Sleep in Microgravity State with COSINOR and Volterra's Kernels Methods

NASA Astrophysics Data System (ADS)

Gaudeua de Gerlicz, C.; Golding, J. G.; Bobola, Ph.; Moutarde, C.; Naji, S.

2008-06-01

The spaceflight under microgravity cause basically biological and physiological imbalance in human being. Lot of study has been yet release on this topic especially about sleep disturbances and on the circadian rhythms (alternation vigilance-sleep, body, temperature...). Factors like space motion sickness, noise, or excitement can cause severe sleep disturbances. For a stay of longer than four months in space, gradual increases in the planned duration of sleep were reported. [1] The average sleep in orbit was more than 1.5 hours shorter than the during control periods on earth, where sleep averaged 7.9 hours. [2] Alertness and calmness were unregistered yield clear circadian pattern of 24h but with a phase delay of 4h.The calmness showed a biphasic component (12h) mean sleep duration was 6.4 structured by 3-5 non REM/REM cycles. Modelisations of neurophysiologic mechanisms of stress and interactions between various physiological and psychological variables of rhythms have can be yet release with the COSINOR method. [3

Is a SIMPLe smartphone application capable of improving biological rhythms in bipolar disorder?

PubMed

Hidalgo-Mazzei, Diego; Reinares, María; Mateu, Ainoa; Juruena, Mario F; Young, Allan H; Pérez-Sola, Víctor; Vieta, Eduard; Colom, Francesc

2017-12-01

Biological rhythms (BR) disturbance has been suggested as a potential mediator of mood episodes in Bipolar Disorder (BD). The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) was designed as an assessment tool to evaluate BR domains comprehensively. In the context of a trial evaluating a smartphone application delivering personalized psychoeducational contents for BD (SIMPLe 1.0), the main aim of this study is to evaluate the potential impact of SIMPLe 1.0 in BR regulation using the BRIAN scale. 51 remitted BD patients were asked to use the application for 3 months. Paired t-test analyses were employed to compare baseline and follow-up BRIAN´s total and domains scores. The sample was divided into completers and non-completers of the study to evaluate differences between groups regarding BRIAN scores using ANCOVA analyses. The BRIAN's mean total score of the whole sample significantly decreased from baseline to post-intervention (35.89 (SD 6.64) vs. 31.18 (SD 6.33), t = 4.29, p = 0.001). At post-intervention, there was a significant difference between groups regarding the total BRIAN mean score (29.47 (SD 6.21) completers vs. 35.92 (SD 3.90) non-completers, t = 2.50, p = 0.02). This difference was maintained after conducting a one-way ANCOVA controlling for pre-intervention BRIAN scores, F (1, 46) = 10.545, p=0.002. A limited sample, pre-post measures, and a short study timeframe could have affected the results. Additional factors affecting BR, such as medication, could not be ruled out. Our results suggest that there are potential positive effects of a psychoeducational smartphone application as an adjunctive to treatment as usual on BD patients' BR. Copyright © 2017 Elsevier B.V. All rights reserved.

Age, circadian rhythms, and sleep loss in flight crews

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Nguyen, DE; Rosekind, Mark R.; Connell, Linda J.

1993-01-01

Age-related changes in trip-induced sleep loss, personality, and the preduty temperature rhythm were analyzed in crews from various flight operations. Eveningness decreased with age. The minimum of the baseline temperature rhythm occurred earlier with age. The amplitude of the baseline temperature rhythm declined with age. Average daily percentage sleep loss during trips increased with age. Among crewmembers flying longhaul flight operations, subjects aged 50-60 averaged 3.5 times more sleep loss per day than subjects aged 20-30. These studies support previous findings that evening types and subjects with later peaking temperature rhythms adapt better to shift work and time zone changes. Age and circadian type may be important considerations for duty schedules and fatigue countermeasures.

Physical models of biological information and adaptation.

PubMed

Stuart, C I

1985-04-07

The bio-informational equivalence asserts that biological processes reduce to processes of information transfer. In this paper, that equivalence is treated as a metaphor with deeply anthropomorphic content of a sort that resists constitutive-analytical definition, including formulation within mathematical theories of information. It is argued that continuance of the metaphor, as a quasi-theoretical perspective in biology, must entail a methodological dislocation between biological and physical science. It is proposed that a general class of functions, drawn from classical physics, can serve to eliminate the anthropomorphism. Further considerations indicate that the concept of biological adaptation is central to the general applicability of the informational idea in biology; a non-anthropomorphic treatment of adaptive phenomena is suggested in terms of variational principles.

An Endogenous Circadian Rhythm in Sleep Inertia Results in Greatest Cognitive Impairment upon Awakening during the Biological Night

PubMed Central

Scheer, Frank A. J. L.; Shea, Thomas J.; Hilton, Michael F.; Shea, Steven A.

2011-01-01

Sleep inertia is the impaired cognitive performance immediately upon awakening, which decays over tens of minutes. This phenomenon has relevance to people who need to make important decisions soon after awakening, such as on-call emergency workers. Such awakenings can occur at varied times of day or night, so the objective of the study was to determine whether or not the magnitude of sleep inertia varies according to the phase of the endogenous circadian cycle. Twelve adults (mean, 24 years; 7 men) with no medical disorders other than mild asthma were studied. Following 2 baseline days and nights, subjects underwent a forced desynchrony protocol composed of seven 28-h sleep/wake cycles, while maintaining a sleep/wakefulness ratio of 1:2 throughout. Subjects were awakened by a standardized auditory stimulus 3 times each sleep period for sleep inertia assessments. The magnitude of sleep inertia was quantified as the change in cognitive performance (number of correct additions in a 2-min serial addition test) across the first 20 min of wakefulness. Circadian phase was estimated from core body temperature (fitted temperature minimum assigned 0°). Data were segregated according to: (1) circadian phase (60° bins); (2) sleep stage; and (3) 3rd of the night after which awakenings occurred (i.e., tertiary 1, 2, or 3). To control for any effect of sleep stage, the circadian rhythm of sleep inertia was initially assessed following awakenings from Stage 2 (62% of awakening occurred from this stage; n = 110). This revealed a significant circadian rhythm in the sleep inertia of cognitive performance (p = 0.007), which was 3.6 times larger during the biological night (circadian bin 300°, ~2300–0300 h in these subjects) than during the biological day (bin 180°, ~1500–1900 h). The circadian rhythm in sleep inertia was still present when awakenings from all sleep stages were included (p = 0.004), and this rhythm could not be explained by changes in underlying sleep drive

An endogenous circadian rhythm in sleep inertia results in greatest cognitive impairment upon awakening during the biological night.

PubMed

Scheer, Frank A J L; Shea, Thomas J; Hilton, Michael F; Shea, Steven A

2008-08-01

Sleep inertia is the impaired cognitive performance immediately upon awakening, which decays over tens of minutes. This phenomenon has relevance to people who need to make important decisions soon after awakening, such as on-call emergency workers. Such awakenings can occur at varied times of day or night, so the objective of the study was to determine whether or not the magnitude of sleep inertia varies according to the phase of the endogenous circadian cycle. Twelve adults (mean, 24 years; 7 men) with no medical disorders other than mild asthma were studied. Following 2 baseline days and nights, subjects underwent a forced desynchrony protocol composed of seven 28-h sleep/wake cycles, while maintaining a sleep/wakefulness ratio of 1:2 throughout. Subjects were awakened by a standardized auditory stimulus 3 times each sleep period for sleep inertia assessments. The magnitude of sleep inertia was quantified as the change in cognitive performance (number of correct additions in a 2-min serial addition test) across the first 20 min of wakefulness. Circadian phase was estimated from core body temperature (fitted temperature minimum assigned 0 degrees ). Data were segregated according to: (1) circadian phase (60 degrees bins); (2) sleep stage; and (3) 3rd of the night after which awakenings occurred (i.e., tertiary 1, 2, or 3). To control for any effect of sleep stage, the circadian rhythm of sleep inertia was initially assessed following awakenings from Stage 2 (62% of awakening occurred from this stage; n = 110). This revealed a significant circadian rhythm in the sleep inertia of cognitive performance (p = 0.007), which was 3.6 times larger during the biological night (circadian bin 300 degrees , approximately 2300-0300 h in these subjects) than during the biological day (bin 180 degrees , approximately 1500-1900 h). The circadian rhythm in sleep inertia was still present when awakenings from all sleep stages were included (p = 0.004), and this rhythm could not be

Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

NASA Astrophysics Data System (ADS)

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.

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells.

PubMed

Fang, Mingzhu; Kang, Hwan-Goo; Park, Youngil; Estrella, Brian; Zarbl, Helmut

2017-09-28

The circadian rhythm is a fundamental physiological process present in all organisms that regulates biological processes ranging from gene expression to sleep behavior. In vertebrates, circadian rhythm is controlled by a molecular oscillator that functions in both the suprachiasmatic nucleus (SCN; central pacemaker) and individual cells comprising most peripheral tissues. More importantly, disruption of circadian rhythm by exposure to light-at-night, environmental stressors and/or toxicants is associated with increased risk of chronic diseases and aging. The ability to identify agents that can disrupt central and/or peripheral biological clocks, and agents that can prevent or mitigate the effects of circadian disruption, has significant implications for prevention of chronic diseases. Although rodent models can be used to identify exposures and agents that induce or prevent/mitigate circadian disruption, these experiments require large numbers of animals. In vivo studies also require significant resources and infrastructure, and require researchers to work all night. Thus, there is an urgent need for a cell-type appropriate in vitro system to screen for environmental circadian disruptors and enhancers in cell types from different organs and disease states. We constructed a vector that drives transcription of the destabilized luciferase in eukaryotic cells under the control of the human PERIOD 2 gene promoter. This circadian reporter construct was stably transfected into human mammary epithelial cells, and circadian responsive reporter cells were selected to develop the in vitro bioluminescence assay. Here, we present a detailed protocol to establish and validate the assay. We further provide details for proof of concept experiments demonstrating the ability of our in vitro assay to recapitulate the in vivo effects of various chemicals on the cellular biological clock. The results indicate that the assay can be adapted to a variety of cell types to screen for both

Circadian Rhythm Sleep-Wake Disorders.

PubMed

Abbott, Sabra M; Reid, Kathryn J; Zee, Phyllis C

2015-12-01

The circadian system regulates the timing and expression of nearly all biological processes, most notably, the sleep-wake cycle, and disruption of this system can result in adverse effects on both physical and mental health. The circadian rhythm sleep-wake disorders (CRSWDs) consist of 5 disorders that are due primarily to pathology of the circadian clock or to a misalignment of the timing of the endogenous circadian rhythm with the environment. This article outlines the nature of these disorders, the association of many of these disorders with psychiatric illness, and available treatment options. Copyright © 2015 Elsevier Inc. All rights reserved.

A Qualitative Investigation of Early Childhood Teachers' Experiences of Rhythm as Pedagogy

ERIC Educational Resources Information Center

Matthews, Douglas R; Ubbes, Valerie A; Freysinger, Valeria J

2016-01-01

Rhythm has been found to enhance not only biological functioning (e.g. balance, timing and coordination), but also to facilitate learning across sociocultural contexts. That is, rhythm may be a method of supporting child development and well-being. Hence, to the extent that children are not exposed to or engaged with rhythm, their development or…

Circadian Rhythm Sleep-Wake Disorders.

PubMed

Pavlova, Milena

2017-08-01

The endogenous circadian rhythms are one of the cardinal processes that control sleep. They are self-sustaining biological rhythms with a periodicity of approximately 24 hours that may be entrained by external zeitgebers (German for time givers), such as light, exercise, and meal times. This article discusses the physiology of the circadian rhythms, their relationship to neurologic disease, and the presentation and treatment of circadian rhythm sleep-wake disorders. Classic examples of circadian rhythms include cortisol and melatonin secretion, body temperature, and urine volume. More recently, the impact of circadian rhythm on several neurologic disorders has been investigated, such as the timing of occurrence of epileptic seizures as well as neurobehavioral functioning in dementia. Further updates include a more in-depth understanding of the symptoms, consequences, and treatment of circadian sleep-wake disorders, which may occur because of extrinsic misalignment with clock time or because of intrinsic dysfunction of the brain. An example of extrinsic misalignment occurs with jet lag during transmeridian travel or with intrinsic circadian rhythm sleep-wake disorders such as advanced or delayed sleep-wake phase disorders. In advanced sleep-wake phase disorder, which is most common in elderly individuals, sleep onset and morning arousal are undesirably early, leading to impaired evening function with excessive sleepiness and sleep-maintenance insomnia with early morning awakening. By contrast, delayed sleep-wake phase disorder is characterized by an inability to initiate sleep before the early morning hours, with subsequent delayed rise time, leading to clinical symptoms of severe sleep-onset insomnia coupled with excessive daytime sleepiness in the morning hours, as patients are unable to "sleep in" to attain sufficient sleep quantity. Irregular sleep-wake rhythm disorder is misentrainment with patches of brief sleep and wakefulness spread throughout the day

Tide-associated biological rhythms of some White Sea littoral invertebrates.

PubMed

Gusev, O A; Golubev, A I

2001-01-01

We report the results from two years of laboratory observations of the tide-associated rhythms of activity of White Sea intertidal invertebrates, Mya arenaria (Bivalvia) and Gammarus finmarchicus (Amphipoda). The tidal associated activity of these invertebrates could not be estimate as a clear circatidal clock. Gammarus activity could be phase shifted by a 0.5 h exposure to turbulent water twice a day for 2-3 days. Mya's rhythm could be changed by a single drainage of aquariums lasting about 15 min. This kind of timing system may be a relatively primitive evolution feature. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Evolution of circadian rhythms in Drosophila melanogaster populations reared in constant light and dark regimes for over 330 generations.

PubMed

Shindey, Radhika; Varma, Vishwanath; Nikhil, K L; Sharma, Vijay Kumar

2017-01-01

Organisms are believed to have evolved circadian clocks as adaptations to deal with cyclic environmental changes, and therefore it has been hypothesized that evolution in constant environments would lead to regression of such clocks. However, previous studies have yielded mixed results, and evolution of circadian clocks under constant conditions has remained an unsettled topic of debate in circadian biology. In continuation of our previous studies, which reported persistence of circadian rhythms in Drosophila melanogaster populations evolving under constant light, here we intended to examine whether circadian clocks and the associated properties evolve differently under constant light and constant darkness. In this regard, we assayed activity-rest, adult emergence and oviposition rhythms of D. melanogaster populations which have been maintained for over 19 years (~330 generations) under three different light regimes - constant light (LL), light-dark cycles of 12:12 h (LD) and constant darkness (DD). We observed that while circadian rhythms in all the three behaviors persist in both LL and DD stocks with no differences in circadian period, they differed in certain aspects of the entrained rhythms when compared to controls reared in rhythmic environment (LD). Interestingly, we also observed that DD stocks have evolved significantly higher robustness or power of free-running activity-rest and adult emergence rhythms compared to LL stocks. Thus, our study, in addition to corroborating previous results of circadian clock evolution in constant light, also highlights that, contrary to the expected regression of circadian clocks, rearing in constant darkness leads to the evolution of more robust circadian clocks which may be attributed to an intrinsic adaptive advantage of circadian clocks and/or pleiotropic functions of clock genes in other traits.

Sleep, rhythms, and the endocrine brain: influence of sex and gonadal hormones.

PubMed

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

2011-11-09

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, modulate photic effects on activity in males point to novel mechanisms of circadian control. Work in aromatase-deficient 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.

Light pollution modifies the expression of daily rhythms and behavior patterns in a nocturnal primate.

PubMed

Le Tallec, Thomas; Perret, Martine; Théry, Marc

2013-01-01

Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14(th) night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes.

Light Pollution Modifies the Expression of Daily Rhythms and Behavior Patterns in a Nocturnal Primate

PubMed Central

Le Tallec, Thomas; Perret, Martine; Théry, Marc

2013-01-01

Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14th night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes. PMID:24236115

Biological dysrhythm in remitted bipolar I disorder.

PubMed

Iyer, Aishwarya; Palaniappan, Pradeep

2017-12-01

Recent treatment guidelines support treatment of biological rhythm abnormalities as a part of treatment of bipolar disorder, but still, literature examining various domains (Sleep, Activity, Social, and Eating) of biological rhythm and its clinical predictors are less. The main aim of our study is to compare various domains of biological rhythm among remitted bipolar I subjects and healthy controls. We also explored for any association between clinical variables and biological rhythm among bipolar subjects. 40 subjects with Bipolar I disorder and 40 healthy controls who met inclusion and exclusion criteria were recruited for the study. Diagnoses were ascertained by a qualified psychiatrist using MINI 5.0. Sociodemographic details, biological rhythm (BRIAN-Biological Rhythm Interview of assessment in Neuropsychiatry) and Sleep functioning (PSQI- Pittsburgh Sleep Quality Index) were assessed in all subjects. Mean age of the Bipolar subjects and controls were 41.25±11.84years and 38.25±11.25 years respectively. Bipolar subjects experienced more biological rhythm disturbance when compared to healthy controls (total BRIAN score being 34.25±9.36 vs 28.2±6.53) (p=0.002). Subsyndromal depressive symptoms (HDRS) had significant positive correlation with BRIAN global scores(r=0.368, p=0.02). Linear regression analysis showed that number of episodes which required hospitalization (β=0.601, t=3.106, P=0.004), PSQI (β=0.394, t=2.609, p=0.014), HDRS (β=0.376, t=2.34, t=0.036) explained 31% of variance in BRIAN scores in remitted bipolar subjects. Biological rhythm disturbances seem to persist even after clinical remission of bipolar illness. More studies to look into the impact of subsyndromal depressive symptoms on biological rhythm are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Field chronobiology of a molluscan bivalve: how the moon and sun cycles interact to drive oyster activity rhythms.

PubMed

Tran, Damien; Nadau, Arnaud; Durrieu, Gilles; Ciret, Pierre; Parisot, Jean-Paul; Massabuau, Jean-Charles

2011-05-01

The present study reports new insights into the complexity of environmental drivers in aquatic animals. The focus of this study was to determine the main forces that drive mollusc bivalve behavior in situ. To answer this question, the authors continuously studied the valve movements of permanently immersed oysters, Crassostrea gigas, during a 1-year-long in situ study. Valve behavior was monitored with a specially build valvometer, which allows continuously recording of up to 16 bivalves at high frequency (10 Hz). The results highlight a strong relationship between the rhythms of valve behavior and the complex association of the sun-earth-moon orbital positions. Permanently immersed C. gigas follows a robust and strong behavior primarily driven by the tidal cycle. The intensity of this tidal driving force is modulated by the neap-spring tides (i.e., synodic moon cycle), which themselves depend of the earth-moon distance (i.e., anomalistic moon cycle). Light is a significant driver of the oysters' biological rhythm, although its power is limited by the tides, which remain the predominant driver. More globally, depending where in the world the bivalves reside, the results suggest their biological rhythms should vary according to the relative importance of the solar cycle and different lunar cycles associated with tide generation. These results highlight the high plasticity of these oysters to adapt to their changing environment.

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

PubMed Central

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

Rain reverses diel activity rhythms in an estuarine teleost

PubMed Central

Payne, Nicholas L.; van der Meulen, Dylan E.; Gannon, Ruan; Semmens, Jayson M.; Suthers, Iain M.; Gray, Charles A.; Taylor, Matthew D.

2013-01-01

Activity rhythms are ubiquitous in nature, and generally synchronized with the day–night cycle. Several taxa have been shown to switch between nocturnal and diurnal activity in response to environmental variability, and these relatively uncommon switches provide a basis for greater understanding of the mechanisms and adaptive significance of circadian (approx. 24 h) rhythms. Plasticity of activity rhythms has been identified in association with a variety of factors, from changes in predation pressure to an altered nutritional or social status. Here, we report a switch in activity rhythm that is associated with rainfall. Outside periods of rain, the estuarine-associated teleost Acanthopagrus australis was most active and in shallower depths during the day, but this activity and depth pattern was reversed in the days following rain, with diurnality restored as estuarine conductivity and turbidity levels returned to pre-rain levels. Although representing the first example of a rain-induced reversal of activity rhythm in an aquatic animal of which we are aware, our results are consistent with established models on the trade-offs between predation risk and foraging efficiency. PMID:23173211

Acoustic pressure reduction at rhythm deviants causes magnetoencephalographic response.

PubMed

Takeshita, Yuya; Yokosawa, Koichi

2015-01-01

Rhythm is an element of music and is important for determining the impression of the music. To investigate the mechanism by which musical rhythmic changes are perceived, magnetoencephalographic responses to rhythm deviants were recorded from 11 healthy volunteers. Auditory stimuli consisting of physically controlled tones were adapted from a song. The auditory stimuli had a steady rhythm, but "early" and "late" deviants were inserted. Only the "early" deviant, which was a tone with a short duration, caused N100m-like prominent transient responses at around the offset of the deviant tone. The latency of the prominent response depended on the descending sound pressure of the deviant tone and was 65 ms after 50% descent. The results suggest that unexpected shortening of tone in a continuous rhythm evokes a transient response and that the response is caused by descending sound pressure of the shortened tone itself, not by the following tones.

Multiscale adaptive analysis of circadian rhythms and intradaily variability: Application to actigraphy time series in acute insomnia subjects

PubMed Central

Rivera, Ana Leonor; Toledo-Roy, Juan C.; Ellis, Jason; Angelova, Maia

2017-01-01

Circadian rhythms become less dominant and less regular with chronic-degenerative disease, such that to accurately assess these pathological conditions it is important to quantify not only periodic characteristics but also more irregular aspects of the corresponding time series. Novel data-adaptive techniques, such as singular spectrum analysis (SSA), allow for the decomposition of experimental time series, in a model-free way, into a trend, quasiperiodic components and noise fluctuations. We compared SSA with the traditional techniques of cosinor analysis and intradaily variability using 1-week continuous actigraphy data in young adults with acute insomnia and healthy age-matched controls. The findings suggest a small but significant delay in circadian components in the subjects with acute insomnia, i.e. a larger acrophase, and alterations in the day-to-day variability of acrophase and amplitude. The power of the ultradian components follows a fractal 1/f power law for controls, whereas for those with acute insomnia this power law breaks down because of an increased variability at the 90min time scale, reminiscent of Kleitman’s basic rest-activity (BRAC) cycles. This suggests that for healthy sleepers attention and activity can be sustained at whatever time scale required by circumstances, whereas for those with acute insomnia this capacity may be impaired and these individuals need to rest or switch activities in order to stay focused. Traditional methods of circadian rhythm analysis are unable to detect the more subtle effects of day-to-day variability and ultradian rhythm fragmentation at the specific 90min time scale. PMID:28753669

Desynchronization of Biological Rhythms in Athletes: Jet Lag

DTIC Science & Technology

1988-10-17

Institute of Mental Health, 1970. 6. Shepard RJ. Sleep, biorhythms and human performance . Sports Medicine 1:11-37, 1984. 7. Stephenson LA, Wenger CB...Medicine 55:1085- 1096, 1984. 10. Winget CM, DeRoshia CW, Holley DC. Circadian rhythms and athletic performance . Medicine and Science in Sports and Exercise...USARIEM, Natick, HA So. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION (if apoikabl) USARIEN, Nat ick MA SGRD-UE-HR

Dark goggles and bright light improve circadian rhythm adaptation to night-shift work.

PubMed

Eastman, C I; Stewart, K T; Mahoney, M P; Liu, L; Fogg, L F

1994-09-01

We compared the contributions of bright light during the night shift and dark goggles during daylight for phase shifting the circadian rhythm of temperature to realign with a 12-hour shift of sleep. After 10 baseline days there were 8 night-work/day-sleep days. Temperature was continuously recorded from 50 subjects. There were four groups in a 2 x 2 design: light (bright, dim), goggles (yes, no). Subjects were exposed to bright light (about 5,000 lux) for 6 hours on the first 2 night shifts. Dim light was < 500 lux. Both bright light and goggles were significant factors for producing circadian rhythm phase shifts. The combination of bright light plus goggles was the most effective, whereas the combination of dim light and no goggles was the least effective. The temperature rhythm either phase advanced or phase delayed when it aligned with daytime sleep. However, when subjects did not have goggles only phase advances occurred. Goggles were necessary for producing phase delays. The most likely explanation is that daylight during the travel-home window after a night shift inhibits phase-delay shifts, and goggles can prevent this inhibition. Larger temperature-rhythm phase shifts were associated with better subjective daytime sleep, less subjective fatigue and better mood.

Adaptation aftereffects in the perception of gender from biological motion.

PubMed

Troje, Nikolaus F; Sadr, Javid; Geyer, Henning; Nakayama, Ken

2006-07-28

Human visual perception is highly adaptive. While this has been known and studied for a long time in domains such as color vision, motion perception, or the processing of spatial frequency, a number of more recent studies have shown that adaptation and adaptation aftereffects also occur in high-level visual domains like shape perception and face recognition. Here, we present data that demonstrate a pronounced aftereffect in response to adaptation to the perceived gender of biological motion point-light walkers. A walker that is perceived to be ambiguous in gender under neutral adaptation appears to be male after adaptation with an exaggerated female walker and female after adaptation with an exaggerated male walker. We discuss this adaptation aftereffect as a tool to characterize and probe the mechanisms underlying biological motion perception.

A review of human physiological and performance changes associated with desynchronosis of biological rhythms

NASA Technical Reports Server (NTRS)

Winget, C. M.; Deroshia, C. W.; Markley, C. L.; Holley, D. C.

1984-01-01

This review discusses the effects, in the aerospace environment, of alterations in approximately 24-h periodicities (circadian rhythms) upon physiological and psychological functions and possible therapies for desynchronosis induced by such alterations. The consequences of circadian rhythm alteration resulting from shift work, transmeridian flight, or altered day lengths are known as desynchronosis, dysrhythmia, dyschrony, jet lag, or jet syndrome. Considerable attention is focused on the ability to operate jet aircraft and manned space vehicles. The importance of environmental cues, such as light-dark cycles, which influence physiological and psychological rhythms is discussed. A section on mathematical models is presented to enable selection and verification of appropriate preventive and corrective measures and to better understand the problem of dysrhythmia.

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

PubMed

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.

Synchronous circadian voltage rhythms with asynchronous calcium rhythms in the suprachiasmatic nucleus

PubMed Central

Enoki, Ryosuke; Oda, Yoshiaki; Mieda, Michihiro; Ono, Daisuke; Honma, Sato; Honma, Ken-ichi

2017-01-01

The suprachiasmatic nucleus (SCN), the master circadian clock, contains a network composed of multiple types of neurons which are thought to form a hierarchical and multioscillator system. The molecular clock machinery in SCN neurons drives membrane excitability and sends time cue signals to various brain regions and peripheral organs. However, how and at what time of the day these neurons transmit output signals remain largely unknown. Here, we successfully visualized circadian voltage rhythms optically for many days using a genetically encoded voltage sensor, ArcLightD. Unexpectedly, the voltage rhythms are synchronized across the entire SCN network of cultured slices, whereas simultaneously recorded Ca2+ rhythms are topologically specific to the dorsal and ventral regions. We further found that the temporal order of these two rhythms is cell-type specific: The Ca2+ rhythms phase-lead the voltage rhythms in AVP neurons but Ca2+ and voltage rhythms are nearly in phase in VIP neurons. We confirmed that circadian firing rhythms are also synchronous and are coupled with the voltage rhythms. These results indicate that SCN networks with asynchronous Ca2+ rhythms produce coherent voltage rhythms. PMID:28270612

NASA Workshop on Biological Adaptation

NASA Technical Reports Server (NTRS)

Morey-Holton, Emily (Editor); Tischler, Marc (Editor)

1988-01-01

A workshop was convened to review the current program in Space Biology Biological Adaptation Research and its objectives and to identify future research directions. Two research areas emerged from these deliberations: gravitational effects on structures and biomineralization and gravity affected regulatory mechanisms. The participants also recommended that research concentrate on rapidly growing animals, since gravity effects may be more pronounced during growth and development. Both research areas were defined and future research directions were identified. The recommendations of the workshop will assist the Life Sciences Division of NASA in it assessment and long-range planning of these areas of space biology. Equally important, the workshop was intended to stimulate thought and research among those attending so that they would, in turn, interest, excite, and involve other members of the academic community in research efforts relevant to these programs.

Rhythm Pattern of Sole through Electrification of the Human Body When Walking

NASA Astrophysics Data System (ADS)

Takiguchi, Kiyoaki; Wada, Takayuki; Tohyama, Shigeki

The rhythm of automatic cyclic movements such as walking is known to be generated by a rhythm generator called CPG in the spinal cord. The measurement of rhythm characteristics in walking is considered to be important for analyzing human bipedal walking and adaptive walking on irregular terrain. In particular, the soles that contact the terrain surface perform flexible movements similar to the movement of the fins of a lungfish, which is considered to be the predecessor of land animals. The sole movements are believed to be a basic movement acquired during prehistoric times. The detailed rhythm pattern of sole motion is considered to be important. We developed a method for measuring electrification without installing device on a subject's body and footwear for stabilizing the electrification of the human body. We measured the rhythm pattern of 20 subjects including 4 infants when walking by using this system and the corresponding equipment. Therefore, we confirmed the commonality of the correlative rhythm patterns of 20 subjects. Further, with regard to an individual subject, the reproducibility of a rhythm pattern with strong correlation coefficient > 0.93 ± 0.5 (mean ± SD) concerning rhythms of trials that are differently conducted on adult subjects could be confirmed.

Circadian rhythm and menopause.

PubMed

Pines, A

2016-12-01

Circadian rhythm is an internal biological clock which initiates and monitors various physiological processes with a fixed time-related schedule. The master circadian pacemaker is located in the suprachiasmatic nucleus in the hypothalamus. The circadian clock undergoes significant changes throughout the life span, at both the physiological and molecular levels. This cyclical physiological process, which is very complex and multifactorial, may be associated with metabolic alterations, atherosclerosis, impaired cognition, mood disturbances and even development of cancer. Sex differences do exist, and the well-known sleep disturbances associated with menopause are a good example. Circadian rhythm was detected in the daily pattern of hot flushes, with a peak in the afternoons. Endogenous secretion of melatonin decreases with aging across genders, and, among women, menopause is associated with a significant reduction of melatonin levels, affecting sleep. Although it might seem that hot flushes and melatonin secretion are likely related, there are not enough data to support such a hypothesis.

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

PubMed

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.

The effect of the number of consecutive night shifts on diurnal rhythms in cortisol, melatonin and heart rate variability (HRV): a systematic review of field studies.

PubMed

Jensen, Marie Aarrebo; Garde, Anne Helene; Kristiansen, Jesper; Nabe-Nielsen, Kirsten; Hansen, Åse Marie

2016-05-01

The purpose of this review is to summarize the current knowledge from field studies on how many consecutive night shifts are required for adaptation of diurnal rhythms in cortisol, melatonin and heart rate variability (HRV) to night work. A systematic search of the databases PubMed and Web of Science resulted in 18 studies selected for review. Cortisol was measured in five studies, melatonin in 11 studies and HRV in four studies. Diurnal rhythms were assessed by use of several different measures based on three to eight samples per day for cortisol and melatonin and 24-h recordings for HRV. Most of the studies in the review were small studies with less than 30 participants, and most studies evaluated diurnal rhythms after only two consecutive night shifts whereas only six studies used seven or more consecutive night shifts. The majority of studies found that adaptation to night work had not occurred after two consecutive night shifts, whereas a small number found evidence for full adaptation after seven consecutive night shifts based on diurnal rhythms in cortisol and melatonin. There are methodological differences in the field studies analyzing diurnal rhythms and large diversity in the occupational fields studied. Nevertheless, we conclude that diurnal rhythms in cortisol, melatonin and HRV are not adapted to night work after 1-3 consecutive night shifts. Studies are needed to establish how many consecutive night shifts are needed for full adaptation of diurnal rhythms to night work.

Evolution of circadian rhythms: from bacteria to human.

PubMed

Bhadra, Utpal; Thakkar, Nirav; Das, Paromita; Pal Bhadra, Manika

2017-07-01

The human body persists in its rhythm as per its initial time zone, and transition always occur according to solar movements around the earth over 24 h. While traveling across different latitudes and longitudes, at the pace exceeding the earth's movement, the changes in the external cues exceed the level of toleration of the body's biological clock. This poses an alteration in our physiological activities of sleep-wake pattern, mental alertness, organ movement, and eating habits, causing them to temporarily lose the track of time. This is further re-synchronized with the physiological cues of the destination over time. The mechanism of resetting of the clocks with varying time zones and cues occur in organisms from bacteria to humans. It is the result of the evolution of different pathways and molecular mechanisms over the time. There has been evolution of numerous comprehensive mechanisms using various research tools to get a deeper insight into the rapid turnover of molecular mechanisms in various species. This review reports insights into the evolution of the circadian mechanism and its evolutionary shift which is vital and plays a major role in assisting different organisms to adapt in different zones and controls their internal biological clocks with changing external cues. Copyright © 2017 Elsevier B.V. All rights reserved.

The volcano mouse Neotomodon alstoni of central Mexico, a biological model in the study of breeding, obesity and circadian rhythms.

PubMed

Miranda-Anaya, M; Pérez-Mendoza, M; Juárez-Tapia, C R; Carmona-Castro, A

2018-04-24

The "Mexican volcano mouse" Neotomodon alstoni, is endemic of the Transverse Neovolcanic Ridge in central Mexico. It is considered as least concern species and has been studied as a potential laboratory model from different perspectives. Two lines of research in neuroendocrinology have been addressed: reproduction and parental care, particularly focused on paternal attention and the influence of testosterone, and studies on physiology and behavior of circadian rhythms, focused on the circadian biology of the species, its circadian locomotor activity and daily neuroendocrine regulation of metabolic parameters related to energy balance. Some mice, when captive, spontaneously develop obesity, which allows for comparisons between lean and obese mice of daily changes in neuronal and metabolic parameters associated with changes in food intake and locomotor activity. This review includes studies that consider this species an attractive animal model where the alteration of circadian rhythms influences the pathogenesis of obesity, specifically with the basic regulation of food intake and metabolism and differences related to sex. This study can be considered as a reference to the comparative animal physiology among rodents. Copyright © 2018. Published by Elsevier Inc.

Glial Cells in the Genesis and Regulation of Circadian Rhythms

PubMed Central

Chi-Castañeda, Donají; Ortega, Arturo

2018-01-01

Circadian rhythms are biological oscillations with a period of ~24 h. These rhythms are orchestrated by a circadian timekeeper in the suprachiasmatic nucleus of the hypothalamus, the circadian “master clock,” which exactly adjusts clock outputs to solar time via photic synchronization. At the molecular level, circadian rhythms are generated by the interaction of positive and negative feedback loops of transcriptional and translational processes of the so-called “clock genes.” A large number of clock genes encode numerous proteins that regulate their own transcription and that of other genes, collectively known as “clock-controlled genes.” In addition to the sleep/wake cycle, many cellular processes are regulated by circadian rhythms, including synaptic plasticity in which an exquisite interplay between neurons and glial cells takes place. In particular, there is compelling evidence suggesting that glial cells participate in and regulate synaptic plasticity in a circadian fashion, possibly representing the missing cellular and physiological link between circadian rhythms with learning and cognition processes. Here we review recent studies in support of this hypothesis, focusing on the interplay between glial cells, synaptic plasticity, and circadian rhythmogenesis. PMID:29483880

Circadian rhythms, athletic performance, and jet lag

PubMed Central

Manfredini, R.; Manfredini, F.; Fersini, C.; Conconi, F.

1998-01-01

Rapid air travel across several time zones exposes the traveller to a shift in his/her internal biological clock. The result is a transient desynchronisation of the circadian rhythm, called jet lag, lasting until the rhythm is rephased to the new environmental conditions. The most commonly experienced symptoms are sleep disorders, difficulties with concentrating, irritability, depression, fatigue, disorientation, loss of appetite, and gastrointestinal disturbance. Apart from the decrements in mental and physical performance directly consequent on such symptoms, competitive athletes are also exposed to the additional negative consequences of a shift from the optimal circadian window of performance. A brief summary of the possible negative effects of jet lag on athletic performance and potentially alleviating strategies is given. 




 PMID:9631214

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

PubMed Central

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

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

PubMed

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 < 0.001). This difference faded after pregnancy, owing to the fall observed in pre-eclampsia (11.8 +/- 3.2 pg/ml, 9.8 +/- 2.1, and 11.1 +/- 2.0, respectively; NS). The rhythm of melatonin concentration was 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 effects of individual biological rhythm differences on sleep quality, daytime sleepiness, and dissociative experiences.

PubMed

Selvi, Yavuz; Kandeger, Ali; Boysan, Murat; Akbaba, Nursel; Sayin, Ayca A; Tekinarslan, Emine; Koc, Basak O; Uygur, Omer F; Sar, Vedat

2017-10-01

Individuals who differ markedly by sleep chronotype, i.e., morning-type or evening-type also differ on a number of psychological, behavioral, and biological variables. Among several other psychological functions, dissociation may also lead to disruption and alteration of consciousness, which may facilitate dream-like experiences. Our study was aimed at an inquiry into the effects of individual biological rhythm differences on sleep quality and daytime sleepiness in conjunction with dissociative experiences. Participants were 372 undergraduate college students, completed a package of psychological instruments, including the Morningness-Eveningness Questionnaire, Dissociative Experiences Scale, Insomnia Severity Index, and Epworth Sleepiness Scale. Using logistic regression models, direct relations of pathological dissociation with sleepiness, sleep quality and circadian preferences were investigated. Poor sleep quality and sleepiness significantly contributed to the variance of dissociative symptomatology. Although there was no substantial linear association between circadian preferences and pathological dissociation, having evening-type preferences of sleep was indirectly associated with higher dissociation mediated by poor sleep quality. Poor sleep quality and daytime sleepiness seems to be significant antecedents of pathological dissociation. Sleep chronotype preferences underlie this relational pattern that chronobiological characteristics seem to influence indirectly on dissociative tendency via sleep quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Development as adaptation: a paradigm for gravitational and space biology

NASA Technical Reports Server (NTRS)

Alberts, Jeffrey R.; Ronca, April E.

2005-01-01

Adaptation is a central precept of biology; it provides a framework for identifying functional significance. We equate mammalian development with adaptation, by viewing the developmental sequence as a series of adaptations to a stereotyped sequence of habitats. In this way development is adaptation. The Norway rat is used as a mammalian model, and the sequence of habitats that is used to define its adaptive-developmental sequence is (a) the uterus, (b) the mother's body, (c) the huddle, and (d) the coterie of pups as they gain independence. Then, within this framework and in relation to each of the habitats, we consider problems of organismal responses to altered gravitational forces (micro-g to hyper-g), especially those encountered during space flight and centrifugation. This approach enables a clearer identification of simple "effects" and active "responses" with respect to gravity. It focuses our attention on functional systems and brings to the fore the manner in which experience shapes somatic adaptation. We argue that this basic developmental approach is not only central to basic issues in gravitational biology, but that it provides a natural tool for understanding the underlying processes that are vital to astronaut health and well-being during long duration flights that will involve adaptation to space flight conditions and eventual re-adaptation to Earth's gravity.

In the darkness of the polar night, scallops keep on a steady rhythm

NASA Astrophysics Data System (ADS)

Tran, Damien; Sow, Mohamedou; Camus, Lionel; Ciret, Pierre; Berge, Jorgen; Massabuau, Jean-Charles

2016-08-01

Although the prevailing paradigm has held that the polar night is a period of biological quiescence, recent studies have detected noticeable activity levels in marine organisms. In this study, we investigated the circadian rhythm of the scallop Chlamys islandica by continuously recording the animal’s behaviour over 3 years in the Arctic (Svalbard). Our results showed that a circadian rhythm persists throughout the polar night and lasts for at least 4 months. Based on observations across three polar nights, we showed that the robustness and synchronicity of the rhythm depends on the angle of the sun below the horizon. The weakest rhythm occurred at the onset of the polar night during the nautical twilight. Surprisingly, the circadian behaviour began to recover during the darkest part of the polar night. Because active rhythms optimize the fitness of an organism, our study brings out that the scallops C. islandica remain active even during the polar night.

Maternal exercise, season and sex modify the daily fetal heart rate rhythm.

PubMed

Sletten, J; Cornelissen, G; Assmus, J; Kiserud, T; Albrechtsen, S; Kessler, J

2018-05-13

The knowledge on biological rhythms is rapidly expanding. We aimed to define the longitudinal development of the daily (24-hour) fetal heart rate rhythm 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. Daily rhythms in fetal heart rate and fetal heart rate variation were 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 daily 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 (P < .001) and nonlinearly in males (quadratic function, P = .001). At 32 and 36 weeks, interindividual rhythm diversity was found in male fetuses during higher maternal physical activity and during the summer season. The dynamic development of the daily fetal heart rate rhythm during the second half of pregnancy is modified by fetal sex, maternal physical activity and season. © 2018 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Biological versus Electronic Adaptive Coloration: How Can One Inform the Other?

DTIC Science & Technology

2012-01-01

Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators. Proc. Natl Acad. Sci. USA 108, 9148–9153. (doi...Patrick B. Dennis, Rajesh R. Naik, Eric Forsythe and inform the other? Biological versus electronic adaptive coloration : how can one References...TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Biological versus electronic adaptive coloration : how can one inform the

Circadian systems biology in Metazoa.

PubMed

Lin, Li-Ling; Huang, Hsuan-Cheng; Juan, Hsueh-Fen

2015-11-01

Systems biology, which can be defined as integrative biology, comprises multistage processes that can be used to understand components of complex biological systems of living organisms and provides hierarchical information to decoding life. Using systems biology approaches such as genomics, transcriptomics and proteomics, it is now possible to delineate more complicated interactions between circadian control systems and diseases. The circadian rhythm is a multiscale phenomenon existing within the body that influences numerous physiological activities such as changes in gene expression, protein turnover, metabolism and human behavior. In this review, we describe the relationships between the circadian control system and its related genes or proteins, and circadian rhythm disorders in systems biology studies. To maintain and modulate circadian oscillation, cells possess elaborative feedback loops composed of circadian core proteins that regulate the expression of other genes through their transcriptional activities. The disruption of these rhythms has been reported to be associated with diseases such as arrhythmia, obesity, insulin resistance, carcinogenesis and disruptions in natural oscillations in the control of cell growth. This review demonstrates that lifestyle is considered as a fundamental factor that modifies circadian rhythm, and the development of dysfunctions and diseases could be regulated by an underlying expression network with multiple circadian-associated signals. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level.

PubMed

Alimohammadi, Nasrollah; Maleki, Bibi; Shahriari, Mohsen; Chitsaz, Ahmad

2015-01-01

Stroke is a stressful event with several functional, physical, psychological, social, and economic problems that affect individuals' different living balances. With coping strategies, patients try to control these problems and return to their natural life. The aim of this study is to investigate the effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level. This study is a clinical trial in which 50 patients, affected by brain stroke and being admitted in the neurology ward of Kashani and Alzahra hospitals, were randomly assigned to control and study groups in Isfahan in 2013. Roy adaptation model care plan was administered in biological dimension in the form of four sessions and phone call follow-ups for 1 month. The forms related to Roy adaptation model were completed before and after intervention in the two groups. Chi-square test and t-test were used to analyze the data through SPSS 18. There was a significant difference in mean score of adaptation in physiological dimension in the study group after intervention (P < 0.001) compared to before intervention. Comparison of the mean scores of changes of adaptation in the patients affected by brain stroke in the study and control groups showed a significant increase in physiological dimension in the study group by 47.30 after intervention (P < 0.001). The results of study showed that Roy adaptation model biological dimension care plan can result in an increase in adaptation in patients with stroke in physiological dimension. Nurses can use this model for increasing patients' adaptation.

The evolutionary biology of musical rhythm: was Darwin wrong?

PubMed

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.

Sirtuins, Melatonin and Circadian Rhythms: Building a Bridge between Aging and Cancer

PubMed Central

Jung-Hynes, Brittney; Reiter, Russel J.; Ahmad, Nihal

2010-01-01

Histone deacetylases (HDACs) have been under intense scientific investigation for a number of years. However, only recently the unique class III HDACs, sirtuins, have gained increasing investigational momentum. Originally linked to longevity in yeast, sirtuins and more specifically, SIRT1 have been implicated in numerous biological processes having both protective and/or detrimental effects. SIRT1 appears to play a critical role in the process of carcinogenesis, especially in age-related neoplasms. Similarly, alterations in circadian rhythms as well as production of the pineal hormone melatonin have been linked to aging and cancer risk. Melatonin has been found act as a differentiating agent in some cancer cells and to lower their invasive and metastatic status. In addition, melatonin synthesis and release occurs in a circadian rhythm fashion and it has been linked to the core circadian machinery genes (Clock, Bmal1, Periods, and Cryptochromes). Melatonin has also been associated with chronotherapy, the timely administration of chemotherapy agents to optimize trends in biological cycles. Interestingly, a recent set of studies have linked SIRT1 to the circadian rhythm machinery through direct deacetylation activity as well as through the NAD+ salvage pathway. In this review, we provide evidence for a possible connection between sirtuins, melatonin, and the circadian rhythm circuitry and their implications in aging, chronomodulation and cancer. PMID:20025641

Rhythm in language acquisition.

PubMed

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.

Gravitational biology and the mammalian circadian timing system

NASA Astrophysics Data System (ADS)

Fuller, Charles A.; Murakami, Dean M.; Sulzman, Frank M.

Mammals have evolved under the influence of many selective pressures. Two of these pressures have been the static force of gravity and the daily variations in the environment due to the rotation of the earth. It is now clear that each of these pressures has led to specific adaptations which influence how organisms respond to changes in either gravity or daily time cues. However, several unpredicted responses to altered gravitational environments occur within the homeostatic and circadian control systems. These results may be particularly relevant to biological and medical issues related to spaceflight. This paper demonstrates that the homeostatic regulation of rat body temperature, heart rate, and activity become depressed following exposure to a 2 G hyperdynamic field, and recovers within 5-6 days. In addition, the circadian rhythms of these same variables exhibit a depression of rhythm amplitude; however, recovery required a minimum of 7 days.

Completing and Adapting Models of Biological Processes

NASA Technical Reports Server (NTRS)

Margaria, Tiziana; Hinchey, Michael G.; Raffelt, Harald; Rash, James L.; Rouff, Christopher A.; Steffen, Bernhard

2006-01-01

We present a learning-based method for model completion and adaptation, which is based on the combination of two approaches: 1) R2D2C, a technique for mechanically transforming system requirements via provably equivalent models to running code, and 2) automata learning-based model extrapolation. The intended impact of this new combination is to make model completion and adaptation accessible to experts of the field, like biologists or engineers. The principle is briefly illustrated by generating models of biological procedures concerning gene activities in the production of proteins, although the main application is going to concern autonomic systems for space exploration.

Short-term influence of cataract surgery on circadian biological rhythm and related health outcomes (CLOCK-IOL trial): study protocol for a randomized controlled trial.

PubMed

Saeki, Keigo; Obayashi, Kenji; Nishi, Tomo; Miyata, Kimie; Maruoka, Shinji; Ueda, Tetsuo; Okamoto, Masahiro; Hasegawa, Taiji; Matsuura, Toyoaki; Tone, Nobuhiro; Ogata, Nahoko; Kurumatani, Norio

2014-12-29

Light information is the most important cue of circadian rhythm which synchronizes biological rhythm with external environment. Circadian misalignment of biological rhythm and external environment is associated with increased risk of depression, insomnia, obesity, diabetes, cardiovascular disease, and cancer. Increased light transmission by cataract surgery may improve circadian misalignment and related health outcomes. Although some observational studies have shown improvement of depression and insomnia after cataract surgery, randomized controlled trials are lacking. We will conduct a parallel-group, assessor-blinded, simple randomized controlled study comparing a cataract surgery group at three months after surgery with a control group to determine whether cataract surgery improves depressive symptoms, sleep quality, body mass regulation, and glucose and lipid metabolism. We will recruit patients who are aged 60 years and over, scheduled to receive their first cataract surgery, and have grade 2 or higher nuclear opacification as defined by the lens opacities classification system III. Exclusion criteria will be patients with major depression, severe corneal opacity, severe glaucoma, vitreous haemorrhage, proliferative diabetic retinopathy, macular oedema, age-related macular degeneration, and patients needing immediate or combined cataract surgery. After baseline participants will be randomized to two groups. Outcomes will be measured at three months after surgery among the intervention group, and three months after baseline among the control group. We will assess depressive symptoms as a primary outcome, using the short version geriatric depression scale (GDS-15). Secondary outcomes will be subjective and actigraph-measured sleep quality, sleepiness, glycated haemoglobin, fasting plasma glucose and triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, body mass index, abdominal circumference, circadian rhythms of physical

Adaptive Laplacian filtering for sensorimotor rhythm-based brain-computer interfaces.

PubMed

Lu, Jun; McFarland, Dennis J; Wolpaw, Jonathan R

2013-02-01

Sensorimotor rhythms (SMRs) are 8-30 Hz oscillations in the electroencephalogram (EEG) recorded from the scalp over sensorimotor cortex that change with movement and/or movement imagery. Many brain-computer interface (BCI) studies have shown that people can learn to control SMR amplitudes and can use that control to move cursors and other objects in one, two or three dimensions. At the same time, if SMR-based BCIs are to be useful for people with neuromuscular disabilities, their accuracy and reliability must be improved substantially. These BCIs often use spatial filtering methods such as common average reference (CAR), Laplacian (LAP) filter or common spatial pattern (CSP) filter to enhance the signal-to-noise ratio of EEG. Here, we test the hypothesis that a new filter design, called an 'adaptive Laplacian (ALAP) filter', can provide better performance for SMR-based BCIs. An ALAP filter employs a Gaussian kernel to construct a smooth spatial gradient of channel weights and then simultaneously seeks the optimal kernel radius of this spatial filter and the regularization parameter of linear ridge regression. This optimization is based on minimizing the leave-one-out cross-validation error through a gradient descent method and is computationally feasible. Using a variety of kinds of BCI data from a total of 22 individuals, we compare the performances of ALAP filter to CAR, small LAP, large LAP and CSP filters. With a large number of channels and limited data, ALAP performs significantly better than CSP, CAR, small LAP and large LAP both in classification accuracy and in mean-squared error. Using fewer channels restricted to motor areas, ALAP is still superior to CAR, small LAP and large LAP, but equally matched to CSP. Thus, ALAP may help to improve the accuracy and robustness of SMR-based BCIs.

Adaptive Laplacian filtering for sensorimotor rhythm-based brain-computer interfaces

NASA Astrophysics Data System (ADS)

Lu, Jun; McFarland, Dennis J.; Wolpaw, Jonathan R.

2013-02-01

Objective. Sensorimotor rhythms (SMRs) are 8-30 Hz oscillations in the electroencephalogram (EEG) recorded from the scalp over sensorimotor cortex that change with movement and/or movement imagery. Many brain-computer interface (BCI) studies have shown that people can learn to control SMR amplitudes and can use that control to move cursors and other objects in one, two or three dimensions. At the same time, if SMR-based BCIs are to be useful for people with neuromuscular disabilities, their accuracy and reliability must be improved substantially. These BCIs often use spatial filtering methods such as common average reference (CAR), Laplacian (LAP) filter or common spatial pattern (CSP) filter to enhance the signal-to-noise ratio of EEG. Here, we test the hypothesis that a new filter design, called an ‘adaptive Laplacian (ALAP) filter’, can provide better performance for SMR-based BCIs. Approach. An ALAP filter employs a Gaussian kernel to construct a smooth spatial gradient of channel weights and then simultaneously seeks the optimal kernel radius of this spatial filter and the regularization parameter of linear ridge regression. This optimization is based on minimizing the leave-one-out cross-validation error through a gradient descent method and is computationally feasible. Main results. Using a variety of kinds of BCI data from a total of 22 individuals, we compare the performances of ALAP filter to CAR, small LAP, large LAP and CSP filters. With a large number of channels and limited data, ALAP performs significantly better than CSP, CAR, small LAP and large LAP both in classification accuracy and in mean-squared error. Using fewer channels restricted to motor areas, ALAP is still superior to CAR, small LAP and large LAP, but equally matched to CSP. Significance. Thus, ALAP may help to improve the accuracy and robustness of SMR-based BCIs.

The effect of real and simulated time-zone shifts upon the circadian rhythms of body temperature, plasma 11-hydroxycorticosteroids, and renal excretion in human subjects

PubMed Central

Elliott, Ann L.; Mills, J. N.; Minors, D. S.; Waterhouse, J. M.

1972-01-01

1. Observations were made upon five subjects who flew through 4½-6 time zones, four of them returning later to their starting point, and upon twenty-three subjects experiencing simulated 6 or 8 hr time zones shifts in either direction in an isolation unit. 2. Measurements were made of plasma concentration of 11-hydroxycorticosteroids, of body temperature, and of urinary excretion of sodium, potassium and chloride. Their rhythm was defined, where possible, by fitting a sine curve of period 24 hr to each separate 24-hr stretch of data and computing the acrophase, or maximum predicted by the sine curve. 3. The adaptation of the plasma steroid rhythm was assessed by the presence of a sharp fall in concentration after the sample collected around 08.00 hr. The time course of adaptation varied widely between individuals; it was usually largely complete by the fourth day after westward, and rather later after eastward, flights. After time shift the pattern often corresponded neither to an adapted nor to an unadapted one, and in a subject followed for many months after a real flight a normal amplitude only appeared 2-3 months after flight. 4. Temperature rhythm adapted by a movement of the acrophase, without change in amplitude, although on some days no rhythm could be observed. This movement was always substantial even on the first day, and was usually nearly complete by the fifth. 5. High nocturnal excretion of electrolyte was often seen in the early days after time shift, more notably after simulated westward flights. Adaptation of urinary electrolyte rhythms usually proceeded as with temperature, but the movement of the acrophase was slower, more variable between individuals, more erratic, and sometimes reversed after partial adaptation. On a few days there were two maxima corresponding to those expected on real and on experimental time. 6. Sodium excretion was much less regular than that of potassium, but adapted more rapidly to time shift, so that the two often

Endocannabinoid signalling: has it got rhythm?

PubMed Central

Vaughn, Linda K; Denning, Gerene; Stuhr, Kara L; de Wit, Harriet; Hill, Matthew N; Hillard, Cecilia J

2010-01-01

Endogenous cannabinoid signalling is widespread throughout the body, and considerable evidence supports its modulatory role in many fundamental physiological processes. The daily and seasonal cycles of the relationship of the earth and sun profoundly affect the terrestrial environment. Terrestrial species have adapted to these cycles in many ways, most well studied are circadian rhythms and hibernation. The purpose of this review was to examine literature support for three hypotheses: (i) endocannabinoid signalling exhibits brain region-specific circadian rhythms; (ii) endocannabinoid signalling modulates the rhythm of circadian processes in mammals; and (iii) changes in endocannabinoid signalling contribute to the state of hibernation. The results of two novel studies are presented. First, we report the results of a study of healthy humans demonstrating that plasma concentrations of the endocannabinoid, N-arachidonylethanolamine (anandamide), exhibit a circadian rhythm. Concentrations of anandamide are threefold higher at wakening than immediately before sleep, a relationship that is dysregulated by sleep deprivation. Second, we investigated differences in endocannabinoids and congeners in plasma from Marmota monax obtained in the summer and during the torpor state of hibernation. We report that 2-arachidonoylglycerol is below detection in M. monax plasma and that concentrations of anandamide are not different. However, plasma concentrations of the anorexigenic lipid oleoylethanolamide were significantly lower in hibernation, while the concentrations of palmitoylethanolamide and 2-oleoylglycerol were significantly greater in hibernation. We conclude that available data support a bidirectional relationship between endocannabinoid signalling and circadian processes, and investigation of the contribution of endocannabinoid signalling to the dramatic physiological changes that occur during hibernation is warranted. This article is part of a themed issue on

Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

ERIC Educational Resources Information Center

Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

2015-01-01

This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

Circadian Rhythm Shapes the Gut Microbiota Affecting Host Radiosensitivity.

PubMed

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.

The Evolutionary Biology of Musical Rhythm: Was Darwin Wrong?

PubMed Central

Patel, Aniruddh D.

2014-01-01

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. PMID:24667562

Biological PET-guided adaptive radiotherapy for dose escalation in head and neck cancer: a systematic review.

PubMed

Hamming-Vrieze, Olga; Navran, Arash; Al-Mamgani, Abrahim; Vogel, Wouter V

2018-06-04

In recent years, the possibility of adapting radiotherapy to changes in biological tissue parameters has emerged. It is hypothesized that early identification of radio-resistant parts of the tumor during treatment provides the possibility to adjust the radiotherapy plan to improve outcome. The aim of this systematic literature review was to evaluate the current state of the art of biological PET-guided adaptive radiotherapy, focusing on dose escalation to radio-resistant tumor. A structured literature search was done to select clinical trials including patients with head and neck cancer of the oral cavity, oropharynx, hypopharynx or larynx, with a PET performed during treatment used to develop biological adaptive radiotherapy by i) delineation of sub-volumes suitable for adaptive re-planning, ii) in silico adaptive treatment planning or iii) treatment of patients with PET based dose escalated adaptive radiotherapy. Nineteen articles were selected, 12 articles analyzing molecular imaging signal during treatment and 7 articles focused on biological adaptive treatment planning, of which two were clinical trials. Studied biological pathways include metabolism (FDG), hypoxia (MISO, FAZA and HX4) and proliferation (FLT). In the development of biological dose adaptation in radiotherapy for head-neck tumors, many aspects of the procedure remain ambiguous. Patient selection, tracer selection for detection of the radio-resistant sub-volumes, timing of adaptive radiotherapy, workflow and treatment planning aspects are discussed in a clinical context.

Clock Genes and Altered Sleep-Wake Rhythms: Their Role in the Development of Psychiatric Disorders.

PubMed

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

PubMed Central

Charrier, Annaëlle; Olliac, Bertrand; Roubertoux, Pierre; Tordjman, Sylvie

2017-01-01

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. PMID:28468274

Toward University Modeling Instruction—Biology: Adapting Curricular Frameworks from Physics to Biology

PubMed Central

Manthey, Seth; Brewe, Eric

2013-01-01

University Modeling Instruction (UMI) is an approach to curriculum and pedagogy that focuses instruction on engaging students in building, validating, and deploying scientific models. Modeling Instruction has been successfully implemented in both high school and university physics courses. Studies within the physics education research (PER) community have identified UMI's positive impacts on learning gains, equity, attitudinal shifts, and self-efficacy. While the success of this pedagogical approach has been recognized within the physics community, the use of models and modeling practices is still being developed for biology. Drawing from the existing research on UMI in physics, we describe the theoretical foundations of UMI and how UMI can be adapted to include an emphasis on models and modeling for undergraduate introductory biology courses. In particular, we discuss our ongoing work to develop a framework for the first semester of a two-semester introductory biology course sequence by identifying the essential basic models for an introductory biology course sequence. PMID:23737628

Toward university modeling instruction--biology: adapting curricular frameworks from physics to biology.

PubMed

Manthey, Seth; Brewe, Eric

2013-06-01

University Modeling Instruction (UMI) is an approach to curriculum and pedagogy that focuses instruction on engaging students in building, validating, and deploying scientific models. Modeling Instruction has been successfully implemented in both high school and university physics courses. Studies within the physics education research (PER) community have identified UMI's positive impacts on learning gains, equity, attitudinal shifts, and self-efficacy. While the success of this pedagogical approach has been recognized within the physics community, the use of models and modeling practices is still being developed for biology. Drawing from the existing research on UMI in physics, we describe the theoretical foundations of UMI and how UMI can be adapted to include an emphasis on models and modeling for undergraduate introductory biology courses. In particular, we discuss our ongoing work to develop a framework for the first semester of a two-semester introductory biology course sequence by identifying the essential basic models for an introductory biology course sequence.

Five Hundred Years of Mercury Exposure and Adaptation

PubMed Central

Lombardi, Guido; Lanzirotti, Antonio; Qualls, Clifford; Socola, Francisco; Ali, Abdul-Mehdi; Appenzeller, Otto

2012-01-01

Mercury is added to the biosphere by anthropogenic activities raising the question of whether changes in the human chromatin, induced by mercury, in a parental generation could allow adaptation of their descendants to mercury. We review the history of Andean mining since pre-Hispanic times in Huancavelica, Peru. Despite the persistent degradation of the biosphere today, no overt signs of mercury toxicity could be discerned in present day inhabitants. However, mercury is especially toxic to the autonomic nervous system (ANS). We, therefore, tested ANS function and biologic rhythms, under the control of the ANS, in 5 Huancavelicans and examined the metal content in their hair. Mercury levels varied from none to 1.014 ppm, significantly less than accepted standards. This was confirmed by microfocused synchrotron X-ray fluorescence analysis. Biologic rhythms were abnormal and hair growth rate per year, also under ANS control, was reduced (P < 0.001). Thus, evidence of mercury's toxicity in ANS function was found without other signs of intoxication. Our findings are consistent with the hypothesis of partial transgenerational inheritance of tolerance to mercury in Huancavelica, Peru. This would generally benefit survival in the Anthropocene, the man-made world, we now live in. PMID:22910643

Evidence of Adaptive Evolutionary Divergence during Biological Invasion

PubMed Central

Lucek, Kay; Sivasundar, Arjun; Seehausen, Ole

2012-01-01

Rapid phenotypic diversification during biological invasions can either arise by adaptation to alternative environments or by adaptive phenotypic plasticity. Where experimental evidence for adaptive plasticity is common, support for evolutionary diversification is rare. Here, we performed a controlled laboratory experiment using full-sib crosses between ecologically divergent threespine stickleback populations to test for a genetic basis of adaptation. Our populations are from two very different habitats, lake and stream, of a recently invaded range in Switzerland and differ in ecologically relevant morphological traits. We found that in a lake-like food treatment lake fish grow faster than stream fish, resembling the difference among wild type individuals. In contrast, in a stream-like food treatment individuals from both populations grow similarly. Our experimental data suggest that genetically determined diversification has occurred within less than 140 years after the arrival of stickleback in our studied region. PMID:23152900

Impairment of heme biosynthesis induces short circadian period in body temperature rhythms in mice.

PubMed

Iwadate, Reiko; Satoh, Yoko; Watanabe, Yukino; Kawai, Hiroshi; Kudo, Naomi; Kawashima, Yoichi; Mashino, Tadahiko; Mitsumoto, Atsushi

2012-07-01

It has been demonstrated that the function of mammalian clock gene transcripts is controlled by the binding of heme in vitro. To examine the effects of heme on biological rhythms in vivo, we measured locomotor activity (LA) and core body temperature (T(b)) in a mouse model of porphyria with impaired heme biosynthesis by feeding mice a griseofulvin (GF)-containing diet. Mice fed with a 2.0% GF-containing diet (GF2.0) transiently exhibited phase advance or phase advance-like phenomenon by 1-3 h in terms of the biological rhythms of T(b) or LA, respectively (both, P < 0.05) while mice were kept under conditions of a light/dark cycle (12 h:12 h). We also observed a transient, ~0.3 h shortening of the period of circadian T(b) rhythms in mice kept under conditions of constant darkness (P < 0.01). Interestingly, the observed duration of abnormal circadian rhythms in GF2.0 mice lasted between 1 and 3 wk after the onset of GF ingestion; this finding correlated well with the extent of impairment of heme biosynthesis. When we examined the effects of therapeutic agents for acute porphyria, heme, and hypertonic glucose on the pathological status of GF2.0 mice, it was found that the intraperitoneal administration of heme (10 mg·kg(-1)·day(-1)) or glucose (9 g·kg(-1)·day(-1)) for 7 days partially reversed (50%) increases in urinary δ-aminolevulinic acids levels associated with acute porphyria. Treatment with heme, but not with glucose, suppressed the phase advance (-like phenomenon) in the diurnal rhythms (P < 0.05) and restored the decrease of heme (P < 0.01) in GF2.0 mice. These results suggest that impairments of heme biosynthesis, in particular a decrease in heme, may affect phase and period of circadian rhythms in animals.

Induction, adaptation and recovery of biological responses: implications for environmental monitoring.

PubMed

Wu, Rudolf S S; Siu, William H L; Shin, Paul K S

2005-01-01

A wide range of biological responses have been used to identify exposure to contaminants, monitor spatial and temporal changes in contamination levels, provide early warning of environmental deterioration and indicate occurrences of adverse ecological consequences. To be useful in environmental monitoring, a biological response must reflect the environmental stress over time in a quantitative way. We here argue that the time required for initial induction, maximum induction, adaptation and recovery of these stress responses must first be fully understood and considered before they can be used in environmental monitoring, or else erroneous conclusions (both false-negative and false-positive) may be drawn when interpreting results. In this study, data on initial induction, maximum induction, adaptation and recovery of stress responses at various biological hierarchies (i.e., molecular, biochemical, physiological, behavioral, cytological, population and community responses) upon exposure to environmentally relevant levels of contaminants (i.e., metals, oil, polycyclic aromatic hydrocarbons (PAHs), organochlorines, organophosphates, endocrine disruptors) were extracted from 922 papers in the biomarker literature and analyzed. Statistical analyses showed that: (a) many stress responses may decline with time after induction (i.e., adaptation), even if the level of stress remains constant; (b) times for maximum induction and recovery of biochemical responses are positively related; (c) there is no evidence to support the general belief that time for induction of responses at a lower biological hierarchy (i.e., molecular responses and biochemical responses) is shorter than that at higher hierarchy (i.e., physiological, cytological and behavioral responses), although longer recovery time is found for population and community responses; (d) there are significant differences in times required for induction and adaptation of biological responses caused by different types of

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

PubMed

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.

Circadian-Rhythm Sleep Disorders in Persons Who Are Totally Blind.

ERIC Educational Resources Information Center

Sack, R. L.; Blood, M. L.; Hughes, R. J.; Lewy, A. J.

1998-01-01

Discusses the diagnosis and management of "non-24-hour sleep-wake syndrome," a form of cyclic insomnia to which people who are totally blind are prone. Covered are incidence and clinical features, formal diagnostic criteria, the biological basis of circadian sleep disorders, circadian rhythms in blind people, pharmacological entrainment,…

Cancer Clocks Out for Lunch: Disruption of Circadian Rhythm and Metabolic Oscillation in Cancer.

PubMed

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.

Cancer Clocks Out for Lunch: Disruption of Circadian Rhythm and Metabolic Oscillation in Cancer

PubMed Central

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. PMID:27500134

Treatment guidelines for Circadian Rhythm Sleep-Wake Disorders of the Polish Sleep Research Society and the Section of Biological Psychiatry of the Polish Psychiatric Association. Part I. Physiology, assessment and therapeutic methods.

PubMed

Wichniak, Adam; Jankowski, Konrad S; Skalski, Michal; Skwarło-Sońta, Krystyna; Zawilska, Jolanta B; Żarowski, Marcin; Poradowska, Ewa; Jernajczyk, Wojciech

2017-10-29

Majority of the physiological processes in the human organism are rhythmic. The most common are the diurnal changes that repeat roughly every 24 hours, called circadian rhythms. Circadian rhythms disorders have negative influence on human functioning. The aim of this article is to present the current understanding of the circadian rhythms physiological role, with particular emphasis on the circadian rhythm sleep-wake disorders (CRSWD), principles of their diagnosis and chronobiological therapy. The guidelines are based on the review of recommendations from the scientific societies involved in sleep medicine and the clinical experiences of the authors. Researchers participating in the preparation of guidelines were invited by the Polish Sleep Research Society and the Section of Biological Psychiatry of the Polish Psychiatric Association, based on their significant contributions in circadian rhythm research and/or clinical experience in the treatment of such disorders. Finally, the guidelines were adjusted to the questions and comments given by the members of both Societies. CRSWD have a significant negative impact on human health and functioning. Standard methods used to assess CRSWD are sleep diaries and sleep logs, while the actigraphy, when available, should be also used. The most effective methods of CRSWD treatment are melatonin administration and light therapy. Behavioral interventions are also recommended. Afourteen-day period of sleep-wake rhythm assessment in CRSWD enables accurate diagnosis, adequate selection of chronobiological interventions, and planning adequate diurnal timing of their application. This type of assessment is quite easy, low-cost, and provides valuable indications how to adjust the therapeutic approach to the circadian phase of the particular patient.

Chronobiological studies of chicken IgY: monitoring of infradian, circadian and ultradian rhythms of IgY in blood and yolk of chickens.

PubMed

He, Jin-Xin; Thirumalai, Diraviyam; Schade, Rüdiger; Zhang, Xiao-Ying

2014-08-15

IgY is the functional equivalent of mammalian IgG found in birds, reptiles and amphibians. Many of its biological aspects have been explored with different approaches. In order to evaluate the rhythmicity of serum and yolk IgY, four chickens were examined and reared under the same conditions. To monitor biological oscillations of IgY in yolk and serum, the eggs and blood samples were collected over a 60 day period and the rhythm of yolk and serum IgY was determined by direct-ELISA. Results indicated that, there is a significant circaseptan rhythm in yolk IgY and circaquattran rhythm in serum IgY. The serum IgY concentration reached a peak in the morning, decreased to a minimum during the daytime and increased again at night revealing a significant circadian rhythm was superimposed by an ultradian rhythm. These data are suited to address the controversies concerning the IgY concentration in egg yolk and blood of laying hens. In addition, this study raised new questions, if the different rhythms in yolk and serum are concerned. Copyright © 2014 Elsevier B.V. All rights reserved.

Serial binary interval ratios improve rhythm reproduction.

PubMed

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.

Serial binary interval ratios improve rhythm reproduction

PubMed Central

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. PMID:23964258

Light and Gravity Effects on Circadian Rhythms of Rhesus Macaques

NASA Technical Reports Server (NTRS)

Fuller, Charles

1997-01-01

Temporal integration of a biological organism's physiological, behavioral and biochemical systems depends upon its circadian timing system. The endogenous period of this timing system is typically synchronized to the 24- hour day by environmental cues. The daily alternation of light and dark has long been known as one of the most potent environmental synchronizers influencing the circadian timing system. Alterations in the lighting environment (length or intensity of light exposure) can also affect the homeostatic state of the organism. A series of experiments was performed using rhesus monkeys with the objective of defining the fundamental properties of the circadian rhythm of body temperature. Three major experiments were performed in addition to several preliminary studies. These experiments explored 1.) the response of the rhesus body temperature rhythm to varying day length and light intensity; 2.) the response of the body temperature rhythm to light exposure as a function of time of day; and 3.) the characteristics of the metabolic heat production rhythm which is responsible for the daily cycle in body temperature. Results of these three completed experiments will be reported here. In addition, preliminary experiments were also performed in social entrainment of rhesus circadian rhythms and the properties of rhesus body temperature rhythms in constant conditions, where no external time cues were provided. Four adult male rhesus monkeys served as subjects in all experiments. All experiments were performed at the California Regional Primate Research Center. Each animal was implanted with a biotelemetry unit that measured deep body temperature. All surgeries were performed by a board certified veterinary surgeon under sterile conditions. The biotelemetry implants also provided an index of activity level in each animal. For metabolic heat production measurements, oxygen consumption and carbon dioxide production were measured and the caloric equivalent of these

Primary Molecular Disorders and Secondary Biological Adaptations in Bartter Syndrome

PubMed Central

Deschênes, Georges; Fila, Marc

2011-01-01

Bartter syndrome is a hereditary disorder that has been characterized by the association of hypokalemia, alkalosis, and the hypertrophy of the juxtaglomerular complex with secondary hyperaldosteronism and normal blood pressure. By contrast, the genetic causes of Bartter syndrome primarily affect molecular structures directly involved in the sodium reabsorption at the level of the Henle loop. The ensuing urinary sodium wasting and chronic sodium depletion are responsible for the contraction of the extracellular volume, the activation of the renin-aldosterone axis, the secretion of prostaglandins, and the biological adaptations of downstream tubular segments, meaning the distal convoluted tubule and the collecting duct. These secondary biological adaptations lead to hypokalemia and alkalosis, illustrating a close integration of the solutes regulation in the tubular structures. PMID:21941653

Circadian Rhythms, the Molecular Clock, and Skeletal Muscle

PubMed Central

Lefta, Mellani; Wolff, Gretchen; Esser, Karyn A.

2015-01-01

Almost all organisms ranging from single cell bacteria to humans exhibit a variety of behavioral, physiological, and biochemical rhythms. In mammals, circadian rhythms control the timing of many physiological processes over a 24-h period, including sleep-wake cycles, body temperature, feeding, and hormone production. This body of research has led to defined characteristics of circadian rhythms based on period length, phase, and amplitude. Underlying circadian behaviors is a molecular clock mechanism found in most, if not all, cell types including skeletal muscle. The mammalian molecular clock is a complex of multiple oscillating networks that are regulated through transcriptional mechanisms, timed protein turnover, and input from small molecules. At this time, very little is known about circadian aspects of skeletal muscle function/metabolism but some progress has been made on understanding the molecular clock in skeletal muscle. The goal of this chapter is to provide the basic terminology and concepts of circadian rhythms with a more detailed review of the current state of knowledge of the molecular clock, with reference to what is known in skeletal muscle. Research has demonstrated that the molecular clock is active in skeletal muscles and that the muscle-specific transcription factor, MyoD, is a direct target of the molecular clock. Skeletal muscle of clock-compromised mice, Bmal1−/− and ClockΔ19 mice, are weak and exhibit significant disruptions in expression of many genes required for adult muscle structure and metabolism. We suggest that the interaction between the molecular clock, MyoD, and metabolic factors, such as PGC-1, provide a potential system of feedback loops that may be critical for both maintenance and adaptation of skeletal muscle. PMID:21621073

Sleep and circadian rhythms

NASA Technical Reports Server (NTRS)

Monk, Timothy H.

1991-01-01

Three interacting processes are involved in the preservation of circadian rhythms: (1) endogenous rhythm generation mechanisms, (2) entrainment mechanisms to keep these rhythms 'on track', and (3) exogenous masking processes stemming from changes in environment and bahavior. These processes, particularly the latter two, can be dramatically affected in individuals of advanced age and in space travelers, with a consequent disruption in sleep and daytime functioning. This paper presents results of a phase-shift experiment investigating the age-related effects of the exogeneous component of circadian rhythms in various physiological and psychological functions by comparing these functions in middle aged and old subjects. Dramatic differences were found between the two age groups in measures of sleep, mood, activation, and performance efficiency.

Seasonal variations in daily rhythms of activity in athletic horses.

PubMed

Bertolucci, C; Giannetto, C; Fazio, F; Piccione, G

2008-07-01

Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses.

Folding into being: early embryology and the epistemology of rhythm.

PubMed

Wellmann, Janina

2015-03-01

Historians have often described embryology and concepts of development in the period around 1800 in terms of "temporalization" or "dynamization". This paper, in contrast, argues that a central epistemological category in the period was "rhythm", which played a major role in the establishment of the emerging discipline of biology. I show that Caspar Friedrich Wolff's epigenetic theory of development was based on a rhythmical notion, namely the hypothesis that organic development occurs as a series of ordered rhythmical repetitions and variations. Presenting Christian Heinrich Pander's and Karl Ernst von Baer's theory of germ layers, I argue that Pander and Baer regarded folding as an organizing principle of ontogenesis, and that the principle's explanatory power stems from their understanding of folding as a rhythmical figuration. In a brief discussion of the notion of rhythm in contemporary music theory, I identify an underlying physiological epistemology in the new musical concept of rhythm around 1800. The paper closes with a more general discussion of the relationship between the rhythmic episteme, conceptions of life, and aesthetic theory at the end of the eighteenth century.

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

PubMed

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 parathyroid hormone circadian rhythm is truly endogenous--a general clinical research center study

NASA Technical Reports Server (NTRS)

el-Hajj Fuleihan, G.; Klerman, E. B.; Brown, E. N.; Choe, Y.; Brown, E. M.; Czeisler, C. A.

1997-01-01

While circulating levels of PTH follow a diurnal pattern, it has been unclear whether these changes are truly endogenous or are dictated by external factors that themselves follow a diurnal pattern, such as sleep-wake cycles, light-dark cycles, meals, or posture. We evaluated the diurnal rhythm of PTH in 11 normal healthy male volunteers in our Intensive Physiologic Monitoring Unit. The first 36 h spent under baseline conditions were followed by 28-40 h of constant routine conditions (CR; enforced wakefulness in the strict semirecumbent position, with the consumption of hourly snacks). During baseline conditions, PTH levels followed a bimodal diurnal rhythm with an average amplitude of 4.2 pg/mL. A primary peak (t1max) occurred at 0314 h, and the secondary peak (t2max) occurred at 1726 h, whereas the primary and secondary nadirs (t1min and t2min) took place, on the average, at 1041 and 2103 h, respectively. This rhythm was preserved under CR conditions, albeit with different characteristics, thus confirming its endogenous nature. The serum ionized calcium (Cai) demonstrated a rhythm in 3 of the 5 subjects studied that varied widely between individuals and did not have any apparent relation to PTH. Urinary calcium/creatinine (UCa/Cr), phosphate/Cr (UPO4/Cr), and sodium/Cr (UNa/Cr) ratios all followed a diurnal rhythm during the baseline day. These rhythms persisted during the CR, although with different characteristics for the first two parameters, whereas that of UNa/Cr was unchanged. In general, the temporal pattern for the UCa/Cr curve was a mirror image of the PTH curve, whereas the UPO4/Cr pattern moved in parallel with the PTH curve. In conclusion, PTH levels exhibit a diurnal rhythm that persists during a CR, thereby confirming that a large component of this rhythm is an endogenous circadian rhythm. The clinical relevance of this rhythm is reflected in the associated rhythms of biological markers of PTH effect at the kidney, namely UCa/Cr and UPO4/Cr.

Vasculature on the clock: Circadian rhythm and vascular dysfunction.

PubMed

Crnko, Sandra; Cour, Martin; Van Laake, Linda W; Lecour, Sandrine

2018-05-17

The master mammalian circadian clock (i.e. central clock), located in the suprachiasmatic nucleus of the hypothalamus, orchestrates the synchronization of the daily behavioural and physiological rhythms to better adapt the organism to the external environment in an anticipatory manner. This central clock is entrained by a variety of signals, the best established being light and food. However, circadian cycles are not simply the consequences of these two cues but are generated by endogenous circadian clocks. Indeed, clock machinery is found in mainly all tissues and cell types, including cells of the vascular system such as endothelial cells, fibroblasts, smooth muscle cells and stem cells. This machinery physiologically contributes to modulate the daily vascular function, and its disturbance therefore plays a major role in the pathophysiology of vascular dysfunction. Therapies targeting the circadian rhythm may therefore be of benefit against vascular disease. Copyright © 2018 Elsevier Inc. All rights reserved.

Biological versus electronic adaptive coloration: how can one inform the other?

PubMed Central

Kreit, Eric; Mäthger, Lydia M.; Hanlon, Roger T.; Dennis, Patrick B.; Naik, Rajesh R.; Forsythe, Eric; Heikenfeld, Jason

2013-01-01

Adaptive reflective surfaces have been a challenge for both electronic paper (e-paper) and biological organisms. Multiple colours, contrast, polarization, reflectance, diffusivity and texture must all be controlled simultaneously without optical losses in order to fully replicate the appearance of natural surfaces and vividly communicate information. This review merges the frontiers of knowledge for both biological adaptive coloration, with a focus on cephalopods, and synthetic reflective e-paper within a consistent framework of scientific metrics. Currently, the highest performance approach for both nature and technology uses colourant transposition. Three outcomes are envisioned from this review: reflective display engineers may gain new insights from millions of years of natural selection and evolution; biologists will benefit from understanding the types of mechanisms, characterization and metrics used in synthetic reflective e-paper; all scientists will gain a clearer picture of the long-term prospects for capabilities such as adaptive concealment and signalling. PMID:23015522

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

PubMed

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.

Rhythms that Speed You Up

ERIC Educational Resources Information Center

Sanabria, Daniel; Capizzi, Mariagrazia; Correa, Angel

2011-01-01

This study investigates whether a rhythm can orient attention to specific moments enhancing people's reaction times (RT). We used a modified version of the temporal orienting paradigm in which an auditory isochronous rhythm was presented prior to an auditory single target. The rhythm could have a fast pace (450 ms Inter-Onset-Interval or IOI) or a…

MicroRNA-433 Dampens Glucocorticoid Receptor Signaling, Impacting Circadian Rhythm and Osteoblastic Gene Expression.

PubMed

Smith, Spenser S; Dole, Neha S; Franceschetti, Tiziana; Hrdlicka, Henry C; Delany, Anne M

2016-10-07

Serum glucocorticoids play a critical role in synchronizing circadian rhythm in peripheral tissues, and multiple mechanisms regulate tissue sensitivity to glucocorticoids. In the skeleton, circadian rhythm helps coordinate bone formation and resorption. Circadian rhythm is regulated through transcriptional and post-transcriptional feedback loops that include microRNAs. How microRNAs regulate circadian rhythm in bone is unexplored. We show that in mouse calvaria, miR-433 displays robust circadian rhythm, peaking just after dark. In C3H/10T1/2 cells synchronized with a pulse of dexamethasone, inhibition of miR-433 using a tough decoy altered the period and amplitude of Per2 gene expression, suggesting that miR-433 regulates rhythm. Although miR-433 does not directly target the Per2 3'-UTR, it does target two rhythmically expressed genes in calvaria, Igf1 and Hif1α. miR-433 can target the glucocorticoid receptor; however, glucocorticoid receptor protein abundance was unaffected in miR-433 decoy cells. Rather, miR-433 inhibition dramatically enhanced glucocorticoid signaling due to increased nuclear receptor translocation, activating glucocorticoid receptor transcriptional targets. Last, in calvaria of transgenic mice expressing a miR-433 decoy in osteoblastic cells (Col3.6 promoter), the amplitude of Per2 and Bmal1 mRNA rhythm was increased, confirming that miR-433 regulates circadian rhythm. miR-433 was previously shown to target Runx2, and mRNA for Runx2 and its downstream target, osteocalcin, were also increased in miR-433 decoy mouse calvaria. We hypothesize that miR-433 helps maintain circadian rhythm in osteoblasts by regulating sensitivity to glucocorticoid receptor signaling. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Diurnal rhythms of the neuroendocrine system in professional riveters with different constitutional types.

PubMed

Gritsko, N; Shulga, V; Ivanova, L

1995-01-01

us to suppose that constitutional dependence of changes of diurnal rhythm of HPA and HPG systems probably underlines the adaptive processes to long time vibration exposure.

Whipworm kinomes reflect a unique biology and adaptation to the host animal.

PubMed

Stroehlein, Andreas J; Young, Neil D; Korhonen, Pasi K; Chang, Bill C H; Nejsum, Peter; Pozio, Edoardo; La Rosa, Giuseppe; Sternberg, Paul W; Gasser, Robin B

2017-11-01

Roundworms belong to a diverse phylum (Nematoda) which is comprised of many parasitic species including whipworms (genus Trichuris). These worms have adapted to a biological niche within the host and exhibit unique morphological characteristics compared with other nematodes. Although these adaptations are known, the underlying molecular mechanisms remain elusive. The availability of genomes and transcriptomes of some whipworms now enables detailed studies of their molecular biology. Here, we defined and curated the full complement of an important class of enzymes, the protein kinases (kinomes) of two species of Trichuris, using an advanced and integrated bioinformatic pipeline. We investigated the transcription of Trichuris suis kinase genes across developmental stages, sexes and tissues, and reveal that selectively transcribed genes can be linked to central roles in developmental and reproductive processes. We also classified and functionally annotated the curated kinomes by integrating evidence from structural modelling and pathway analyses, and compared them with other curated kinomes of phylogenetically diverse nematode species. Our findings suggest unique adaptations in signalling processes governing worm morphology and biology, and provide an important resource that should facilitate experimental investigations of kinases and the biology of signalling pathways in nematodes. Copyright © 2017 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Endogenous circadian rhythm in vasovagal response to head-up tilt

PubMed Central

Hu, Kun; Scheer, Frank AJL; Laker, Michael; Smales, Carolina; Shea, Steven A

2011-01-01

Background The incidence of syncope exhibits a daily pattern with more occurrences in the morning, possibly due to influences from the endogenous circadian system and/or the daily pattern of behavioral/emotional stimuli. This study tested the hypothesis that the circadian system modulates cardiovascular responses to postural stress, leading to increased susceptibility to syncope at specific times of day. Methods and Results Twelve subjects underwent a 13-day in-laboratory protocol, in which subjects’ sleep-wake cycles were adjusted to 20 hours for 12 cycles. A 15-minute title-table test (60° head-up) was performed ~4.5 hours after scheduled awakening in each cycle so that twelve tests in each subject were distributed evenly across the circadian cycle. Out of 144 tests, signs/symptoms of presyncope were observed in 21 tests in 6 subjects. These presyncope events displayed a clear circadian rhythm (P=0.028) with 17 cases (81%) in the circadian phase range corresponding to ~22:30-10:30 (4.25 times of the probability from the other half of the circadian cycle). Significant circadian rhythms were also observed in hemodynamic and autonomic function markers (blood pressure, heart rate, epinephrine, norepinephrine, and indices of cardiac vagal tone) that may underlie the circadian rhythm of presyncope susceptibility. Conclusion The circadian system affects cardiovascular responses to postural stressors resulting in greater susceptibility to presyncope during the biological night. This finding suggests that night-shift workers and people with disrupted sleep at night may have great risk of syncope due to their exposure to postural stressors during the biological night. PMID:21339480

The Rhythm of Perception: Entrainment to Acoustic Rhythms Induces Subsequent Perceptual Oscillation.

PubMed

Hickok, Gregory; Farahbod, Haleh; Saberi, Kourosh

2015-07-01

Acoustic rhythms are pervasive in speech, music, and environmental sounds. Recent evidence for neural codes representing periodic information suggests that they may be a neural basis for the ability to detect rhythm. Further, rhythmic information has been found to modulate auditory-system excitability, which provides a potential mechanism for parsing the acoustic stream. Here, we explored the effects of a rhythmic stimulus on subsequent auditory perception. We found that a low-frequency (3 Hz), amplitude-modulated signal induces a subsequent oscillation of the perceptual detectability of a brief nonperiodic acoustic stimulus (1-kHz tone); the frequency but not the phase of the perceptual oscillation matches the entrained stimulus-driven rhythmic oscillation. This provides evidence that rhythmic contexts have a direct influence on subsequent auditory perception of discrete acoustic events. Rhythm coding is likely a fundamental feature of auditory-system design that predates the development of explicit human enjoyment of rhythm in music or poetry. © The Author(s) 2015.

The circadian clock controls toll-like receptor 9-mediated innate and adaptive immunity

PubMed Central

Silver, Adam C.; Arjona, Alvaro; Walker, Wendy E.; Fikrig, Erol

2012-01-01

Circadian rhythms refer to biologic processes that oscillate with a period of approximately 24 hours. These rhythms are sustained by a molecular clock and provide a temporal matrix that ensures the coordination of homeostatic processes with the periodicity of environmental challenges. We demonstrate the circadian molecular clock controls the expression and function of toll like receptor 9 (TLR9). In a vaccination model using TLR9 ligand as adjuvant, mice immunized at the time of enhanced TLR9 responsiveness presented weeks later with an improved adaptive immune response. In a TLR9-dependent mouse model of sepsis, we found that disease severity was dependent on the timing of sepsis induction, coinciding with the daily changes in TLR9 expression and function. These findings unveil a direct molecular link between the circadian and innate immune systems with important implications for immunoprophylaxis and immunotherapy. PMID:22342842

Inherited variation in circadian rhythm genes and risks of prostate cancer and three other cancer sites in combined cancer consortia.

PubMed

Gu, Fangyi; Zhang, Han; Hyland, Paula L; Berndt, Sonja; Gapstur, Susan M; Wheeler, William; Ellipse Consortium, The; Amos, Christopher I; Bezieau, Stephane; Bickeböller, Heike; Brenner, Hermann; Brennan, Paul; Chang-Claude, Jenny; Conti, David V; Doherty, Jennifer Anne; Gruber, Stephen B; Harrison, Tabitha A; Hayes, Richard B; Hoffmeister, Michael; Houlston, Richard S; Hung, Rayjean J; Jenkins, Mark A; Kraft, Peter; Lawrenson, Kate; McKay, James; Markt, Sarah; Mucci, Lorelei; Phelan, Catherine M; Qu, Conghui; Risch, Angela; Rossing, Mary Anne; Wichmann, H-Erich; Shi, Jianxin; Schernhammer, Eva; Yu, Kai; Landi, Maria Teresa; Caporaso, Neil E

2017-11-01

Circadian disruption has been linked to carcinogenesis in animal models, but the evidence in humans is inconclusive. Genetic variation in circadian rhythm genes provides a tool to investigate such associations. We examined associations of genetic variation in nine core circadian rhythm genes and six melatonin pathway genes with risk of colorectal, lung, ovarian and prostate cancers using data from the Genetic Associations and Mechanisms in Oncology (GAME-ON) network. The major results for prostate cancer were replicated in the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial, and for colorectal cancer in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). The total number of cancer cases and controls was 15,838/18,159 for colorectal, 14,818/14,227 for prostate, 12,537/17,285 for lung and 4,369/9,123 for ovary. For each cancer site, we conducted gene-based and pathway-based analyses by applying the summary-based Adaptive Rank Truncated Product method (sARTP) on the summary association statistics for each SNP within the candidate gene regions. Aggregate genetic variation in circadian rhythm and melatonin pathways were significantly associated with the risk of prostate cancer in data combining GAME-ON and PLCO, after Bonferroni correction (p pathway  < 0.00625). The two most significant genes were NPAS2 (p gene  = 0.0062) and AANAT (p gene  = 0.00078); the latter being significant after Bonferroni correction. For colorectal cancer, we observed a suggestive association with the circadian rhythm pathway in GAME-ON (p pathway  = 0.021); this association was not confirmed in GECCO (p pathway  = 0.76) or the combined data (p pathway  = 0.17). No significant association was observed for ovarian and lung cancer. These findings support a potential role for circadian rhythm and melatonin pathways in prostate carcinogenesis. Further functional studies are needed to better understand the underlying biologic

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

PubMed

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

2002-11-01

< 24 h. This phenomenon was not gender-related but was age-related since it was seldom observed in adolescent subjects. Hand-side differences in the grip strength rhythms in the same individuals were detected, the tau being ultradian rather than circadian in adolescent subjects while in mature subjects the tau frequently differed from that of the rhythm in CRT. These findings further support the hypothesis that functional biological clocks exist in both the left and right hemispheres of the human cortex.

Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure

NASA Technical Reports Server (NTRS)

Duffy, J. F.; Kronauer, R. E.; Czeisler, C. A.

1996-01-01

1. Both the timing of behavioural events (activity, sleep and social interactions) and the environmental light-dark cycle have been reported to contribute to entrainment of human circadian rhythms to the 24 h day. Yet, the relative contribution of those putative behavioural synchronizers to that of light exposure remains unclear. 2. To investigate this, we inverted the schedule of rest, sedentary activity and social contact of thirty-two young men either with or without exposure to bright light. 3. On this inverted schedule, the endogenous component of the core temperature rhythm of subjects who were exposed to bright light showed a significant phase shift, demonstrating that they were adapting to the new schedule. In contrast, the core temperature rhythm of subjects who were not exposed to bright light moved on average 0.2 h later per day and after 10 days had not significantly adapted to the new schedule. 4. The direction of phase shift in the groups exposed to bright light was dependent on the time of bright light exposure, while control subjects drifted to a later hour regardless of the timing of their schedule of sleep timing, social contact and meals. 5. These results support the concept that the light-dark cycle is the most important synchronizer of the human circadian system. They suggest that inversion of the sleep-wake, rest-activity and social contact cycles provides relatively minimal drive for resetting the human circadian pacemaker. 6. These data indicate that interventions designed to phase shift human circadian rhythms for adjustment to time zone changes or altered work schedules should focus on properly timed light exposure.

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

PubMed

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.

Adaptively Selecting Biology Questions Generated from a Semantic Network

ERIC Educational Resources Information Center

Zhang, Lishan; VanLehn, Kurt

2017-01-01

The paper describes a biology tutoring system with adaptive question selection. Questions were selected for presentation to the student based on their utilities, which were estimated from the chance that the student's competence would increase if the questions were asked. Competence was represented by the probability of mastery of a set of biology…

Redox rhythm reinforces the circadian clock to gate immune response.

PubMed

Zhou, Mian; Wang, Wei; Karapetyan, Sargis; Mwimba, Musoki; Marqués, Jorge; Buchler, Nicolas E; Dong, Xinnian

2015-07-23

Recent studies have shown that in addition to the transcriptional circadian clock, many organisms, including Arabidopsis, have a circadian redox rhythm driven by the organism's metabolic activities. It has been hypothesized that the redox rhythm is linked to the circadian clock, but the mechanism and the biological significance of this link have only begun to be investigated. Here we report that the master immune regulator NPR1 (non-expressor of pathogenesis-related gene 1) of Arabidopsis is a sensor of the plant's redox state and regulates transcription of core circadian clock genes even in the absence of pathogen challenge. Surprisingly, acute perturbation in the redox status triggered by the immune signal salicylic acid does not compromise the circadian clock but rather leads to its reinforcement. Mathematical modelling and subsequent experiments show that NPR1 reinforces the circadian clock without changing the period by regulating both the morning and the evening clock genes. This balanced network architecture helps plants gate their immune responses towards the morning and minimize costs on growth at night. Our study demonstrates how a sensitive redox rhythm interacts with a robust circadian clock to ensure proper responsiveness to environmental stimuli without compromising fitness of the organism.

Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions.

PubMed

Al-Haidary, Ahmed A; Abdoun, Khalid A; Samara, Emad M; Okab, Aly B; Sani, Mamane; Refinetti, Roberto

2016-08-01

Camels are well adapted to hot arid environments and can contribute significantly to the economy of developing countries in arid regions of the world. Full understanding of the physiology of camels requires understanding of the internal temporal order of the body, as reflected in daily or circadian rhythms. In the current study, we investigated the daily rhythmicity of 20 physiological variables in camels exposed to natural oscillations of ambient temperature in a desert environment and compared the daily temporal courses of the variables. We also studied the rhythm of core body temperature under experimental conditions with constant ambient temperature in the presence and absence of a light-dark cycle. The obtained results indicated that different physiological variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day, starting with plasma cholesterol, which peaks 24min after midnight, and ending with plasma calcium, which peaks 3h before midnight. Furthermore, the rhythm of core body temperature persisted in the absence of environmental rhythmicity, thus confirming its endogenous nature. The observed delay in the acrophase of core body temperature rhythm under constant conditions suggests that the circadian period is longer than 24h. Further studies with more refined experimental manipulation of different variables are needed to fully elucidate the causal network of circadian rhythms in dromedary camels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Children's Ability to Learn Evolutionary Explanations for Biological Adaptation

ERIC Educational Resources Information Center

Shtulman, Andrew; Neal, Cara; Lindquist, Gabrielle

2016-01-01

Research Findings: Evolution by natural selection is often relegated to the high school curriculum on the assumption that younger students cannot grasp its complexity. We sought to test that assumption by teaching children ages 4-12 (n = 96) a selection-based explanation for biological adaptation and comparing their success to that of adults…

Alignment strategies for the entrainment of music and movement rhythms.

PubMed

Moens, Bart; Leman, Marc

2015-03-01

Theories of entrainment assume that spontaneous entrainment emerges from dynamic laws that operate via mediators on interactions, whereby entrainment is facilitated if certain conditions are fulfilled. In this study, we show that mediators can be built that affect the entrainment of human locomotion to music. More specifically, we built D-Jogger, a music player that functions as a mediator between music and locomotion rhythms. The D-Jogger makes it possible to manipulate the timing differences between salient moments of the rhythms (beats and footfalls) through the manipulation of the musical period and phase, which affect the condition in which entrainment functions. We conducted several experiments to explore different strategies for manipulating the entrainment of locomotion and music. The results of these experiments showed that spontaneous entrainment can be manipulated, thereby suggesting different strategies on how to embark. The findings furthermore suggest a distinction among different modalities of entrainment: finding the beat (the most difficult part of entrainment), keeping the beat (easier, as a temporal scheme has been established), and being in phase (no entrainment is needed because the music is always adapted to the human rhythm). This study points to a new avenue of research on entrainment and opens new perspectives for the neuroscience of music. © 2014 New York Academy of Sciences.

Adaptable data management for systems biology investigations.

PubMed

Boyle, John; Rovira, Hector; Cavnor, Chris; Burdick, David; Killcoyne, Sarah; Shmulevich, Ilya

2009-03-06

Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry). We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community.

Adaptable data management for systems biology investigations

PubMed Central

Boyle, John; Rovira, Hector; Cavnor, Chris; Burdick, David; Killcoyne, Sarah; Shmulevich, Ilya

2009-01-01

Background Within research each experiment is different, the focus changes and the data is generated from a continually evolving barrage of technologies. There is a continual introduction of new techniques whose usage ranges from in-house protocols through to high-throughput instrumentation. To support these requirements data management systems are needed that can be rapidly built and readily adapted for new usage. Results The adaptable data management system discussed is designed to support the seamless mining and analysis of biological experiment data that is commonly used in systems biology (e.g. ChIP-chip, gene expression, proteomics, imaging, flow cytometry). We use different content graphs to represent different views upon the data. These views are designed for different roles: equipment specific views are used to gather instrumentation information; data processing oriented views are provided to enable the rapid development of analysis applications; and research project specific views are used to organize information for individual research experiments. This management system allows for both the rapid introduction of new types of information and the evolution of the knowledge it represents. Conclusion Data management is an important aspect of any research enterprise. It is the foundation on which most applications are built, and must be easily extended to serve new functionality for new scientific areas. We have found that adopting a three-tier architecture for data management, built around distributed standardized content repositories, allows us to rapidly develop new applications to support a diverse user community. PMID:19265554

ROS signaling pathways and biological rhythms: perspectives in crustaceans.

PubMed

Fanjul-Moles, Maria Luisa

2013-01-01

This work reviews concepts regarding the endogenous circadian clock and the relationship between oxidative stress (OS), light and entrainment in different organisms including crustaceans, particularly crayfish. In the first section, the molecular control of circadian rhythms in invertebrates, particularly in Drosophila, is reviewed, and this model is contrasted with recent reports on the circadian genes and proteins in crayfish. Second, the redox mechanisms and signaling pathways that participate in the entrainment of the circadian clock in different organisms are reviewed. Finally, the light signals and transduction pathways involved in the entrainment of the circadian clock, specifically in relation to cryptochromes (CRYs) and their dual role in the circadian clock of different animal groups and their possible relationship to the circadian clock and redox mechanisms in crustaceans is discussed. The relationship between metabolism, ROS signals and transcription factors, such as HIF-1 alpha in crayfish, as well as the possibility that HIF-1 alpha participates in the regulation of circadian control genes (ccgs) in crustaceans is discussed.

Receptors as a master key for synchronization of rhythms

NASA Astrophysics Data System (ADS)

Nagano, Seido

2004-03-01

A simple, but general scheme to achieve synchronization of rhythms was derived. The scheme has been inductively generalized from the modelling study of cellular slime mold. It was clarified that biological receptors work as apparatuses that can convert external stimulus to the form of nonlinear interaction within individual oscillators. Namely, the mathematical model receptor works as a nonlinear coupling apparatus between nonlinear oscillators. Thus, synchronization is achieved as a result of competition between two kinds of non-linearities, and to achieve synchronization, even a small external stimulation via model receptors can change the characteristics of individual oscillators significantly. The derived scheme is very simple mathematically, but it is a very powerful scheme as numerically demonstrated. The biological receptor scheme should significantly help understanding of synchronization phenomena in biology since groups of limit cycle oscillators and receptors are ubiquitous in biological systems. Reference: S. Nagano, Phys Rev. E67, 056215(2003)

Timing of host feeding drives rhythms in parasite replication

PubMed Central

Cumnock, Katherine; Schneider, David; Subudhi, Amit; Savill, Nicholas J.

2018-01-01

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

Quantum Information Biology: From Theory of Open Quantum Systems to Adaptive Dynamics

NASA Astrophysics Data System (ADS)

Asano, Masanari; Basieva, Irina; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro

This chapter reviews quantum(-like) information biology (QIB). Here biology is treated widely as even covering cognition and its derivatives: psychology and decision making, sociology, and behavioral economics and finances. QIB provides an integrative description of information processing by bio-systems at all scales of life: from proteins and cells to cognition, ecological and social systems. Mathematically QIB is based on the theory of adaptive quantum systems (which covers also open quantum systems). Ideologically QIB is based on the quantum-like (QL) paradigm: complex bio-systems process information in accordance with the laws of quantum information and probability. This paradigm is supported by plenty of statistical bio-data collected at all bio-scales. QIB re ects the two fundamental principles: a) adaptivity; and, b) openness (bio-systems are fundamentally open). In addition, quantum adaptive dynamics provides the most generally possible mathematical representation of these principles.

The Effects of the Mars Exploration Rovers (MER) Work Schedule Regime on Locomotor Activity Circadian Rhythms, Sleep and Fatigue

NASA Technical Reports Server (NTRS)

DeRoshia, Charles W.; Colletti, Laura C.; Mallis, Melissa M.

2008-01-01

This study assessed human adaptation to a Mars sol by evaluating sleep metrics obtained by actigraphy and subjective responses in 22 participants, and circadian rhythmicity in locomotor activity in 9 participants assigned to Mars Exploration Rover (MER) operational work schedules (24.65 hour days) at the Jet Propulsion Laboratory in 2004. During MER operations, increased work shift durations and reduced sleep durations and time in bed were associated with the appearance of pronounced 12-hr (circasemidian) rhythms with reduced activity levels. Sleep duration, workload, and circadian rhythm stability have important implications for adaptability and maintenance of operational performance not only of MER operations personnel but also in space crews exposed to a Mars sol of 24.65 hours during future Mars missions.

Rhythms at the bottom of the deep sea: Cyclic current flow changes and melatonin patterns in two species of demersal fish

NASA Astrophysics Data System (ADS)

Wagner, H.-J.; Kemp, K.; Mattheus, U.; Priede, I. G.

2007-11-01

We have studied physical and biological rhythms in the deep demersal habitat of the Northeastern Atlantic. Current velocity and direction changes occurred at intervals of 12.4 h, demonstrating that they could have an impact of tidal activity, and also showed indications of other seasonal changes. As an indicator of biological rhythms, we measured the content of pineal and retinal melatonin in the grenadier Coryphaenoides armatus and the deep-sea eel Synaphobranchus kaupii, and determined the spontaneous release of melatonin in long-term (52 h minimum) cultures of isolated pineal organs and retinae in S. kaupii. The results of the release experiments show statistically significant signs of synchronicity and periodicity suggesting the presence of an endogenous clock. The melatonin content data show large error bars typical of cross-sectional population studies. When the data are plotted according to a lunar cycle, taken as indication of a tidal rhythm, both species show peak values at the beginning of the lunar day and night and lower values during the second half of lunar day and night and during moonrise and moonset. Statistical analysis, however, shows that the periodicity of the melatonin content is not significant. Taken together these observations strongly suggest that (1) biological rhythms are present in demersal fish, (2) the melatonin metabolism shows signs of periodicity, and (3) tidal currents may act as zeitgeber at the bottom of the deep sea.

Management and outcome of patients with acute myocardial infarction presenting with pacemaker rhythm.

PubMed

Bertel, Noemi; Witassek, Fabienne; Puhan, Milo; Erne, Paul; Rickli, Hans; Naegeli, Barbara; Pedrazzini, Giovanni; Stauffer, Jean-Christophe; Radovanovic, Dragana

2017-03-01

Diagnosis of acute myocardial infarction (MI) is challenging in pacemaker patients. Little is known about this patient group. Patients with MI enrolled in the Swiss national AMIS Plus registry between January 2005 and December 2015 were analyzed. All patients with either paced ventricular rhythm or sinus rhythm with intrinsic ventricular conduction (IVC) were included in this study. Outcomes using crude data and propensity score matching were compared between patients with pacemaker rhythm and patients with IVC. The primary endpoint was in-hospital death. Data from 300 patients with paced rhythm and 27,595 with IVC were analyzed. Patients with pacemaker rhythm were older (78.2y vs 65.4y; p<0.001), had more comorbidities (Charlson Index (CCI)>1: 54.0% vs 21.1%; p<0.001) and a higher rate of heart failure upon presentation (Killip class>2, 11.0% vs 5.9%; p<0.001) compared to patients with IVC. Door to balloon time in patients undergoing acute PCI is markedly delayed in contrast to patients with IVC (280min vs 85min; p<0.001). Consequently, crude mortality in patients with pacemakers was high (11.3% vs 4.6%; p<0.001). However, when analyzed with propensity matching for gender, age, CCI>1 and Killip>2, mortality was similar (11.2% vs 10.5%; p=0.70). Pacemaker patients with acute MI represent a high-risk group with doubled crude mortality compared to patients without pacemakers, due to higher age and higher Killip class. Diagnosis is difficult and results in delayed treatment. Treatment algorithms for MI with paced rhythm should possibly be adapted to those used for STEMI or new left bundle branch block. NCT01305785. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

How do precision medicine and system biology response to human body's complex adaptability?

PubMed

Yuan, Bing

2016-12-01

In the field of life sciences, although system biology and "precision medicine" introduce some complex scientifific methods and techniques, it is still based on the "analysis-reconstruction" of reductionist theory as a whole. Adaptability of complex system increase system behaviour uncertainty as well as the difficulties of precise identifification and control. It also put systems biology research into trouble. To grasp the behaviour and characteristics of organism fundamentally, systems biology has to abandon the "analysis-reconstruction" concept. In accordance with the guidelines of complexity science, systems biology should build organism model from holistic level, just like the Chinese medicine did in dealing with human body and disease. When we study the living body from the holistic level, we will fifind the adaptability of complex system is not the obstacle that increases the diffificulty of problem solving. It is the "exceptional", "right-hand man" that helping us to deal with the complexity of life more effectively.

Multiple-scale neuroendocrine signals connect brain and pituitary hormone rhythms

PubMed Central

Romanò, Nicola; Guillou, Anne; Martin, Agnès O; Mollard, Patrice

2017-01-01

Small assemblies of hypothalamic “parvocellular” neurons release their neuroendocrine signals at the median eminence (ME) to control long-lasting pituitary hormone rhythms essential for homeostasis. How such rapid hypothalamic neurotransmission leads to slowly evolving hormonal signals remains unknown. Here, we show that the temporal organization of dopamine (DA) release events in freely behaving animals relies on a set of characteristic features that are adapted to the dynamic dopaminergic control of pituitary prolactin secretion, a key reproductive hormone. First, locally generated DA release signals are organized over more than four orders of magnitude (0.001 Hz–10 Hz). Second, these DA events are finely tuned within and between frequency domains as building blocks that recur over days to weeks. Third, an integration time window is detected across the ME and consists of high-frequency DA discharges that are coordinated within the minutes range. Thus, a hierarchical combination of time-scaled neuroendocrine signals displays local–global integration to connect brain–pituitary rhythms and pace hormone secretion. PMID:28193889

Statistical methods for detecting and comparing periodic data and their application to the nycthemeral rhythm of bodily harm: A population based study

PubMed Central

2010-01-01

Background Animals, including humans, exhibit a variety of biological rhythms. This article describes a method for the detection and simultaneous comparison of multiple nycthemeral rhythms. Methods A statistical method for detecting periodic patterns in time-related data via harmonic regression is described. The method is particularly capable of detecting nycthemeral rhythms in medical data. Additionally a method for simultaneously comparing two or more periodic patterns is described, which derives from the analysis of variance (ANOVA). This method statistically confirms or rejects equality of periodic patterns. Mathematical descriptions of the detecting method and the comparing method are displayed. Results Nycthemeral rhythms of incidents of bodily harm in Middle Franconia are analyzed in order to demonstrate both methods. Every day of the week showed a significant nycthemeral rhythm of bodily harm. These seven patterns of the week were compared to each other revealing only two different nycthemeral rhythms, one for Friday and Saturday and one for the other weekdays. PMID:21059197

Disturbed mouse circadian rhythm before the Kobe EQ in 1995

NASA Astrophysics Data System (ADS)

Yokoi, Sayoko

2013-04-01

Legends of macro-anomalies before large earthquakes have been passed down for generations in Asia. Most of the statements on earthquake precursors are considered unreliable afterthoughts by traditional scientists. However, disturbed biological rhythms in mice were observed before the Kobe EQ in 1995 (Yokoi et al, 2003). The records of unusual mouse behavior before the earthquake were obtained to study biological clock at Institute for Protein Research, Osaka University. It is clarified that the disturbance was very rare phenomena statistically. Similar phenomenon was observed before the Wenchuan earthquake in 2008, too (Li et al, 2009). In the presentation, I will discuss the phenomena as one example of preseismic unusual animal behaviors.

Molecular Approach to Hypothalamic Rhythms: Isolation of Novel Indoleamine Receptor Genes

DTIC Science & Technology

1993-03-14

well PCR Cloning, Library Screening, and Sequence Analysis. as the lateral geniculate and superior colliculus. Serotonergic Poly(A)-enriched RNA was...CAMP, one negatively (G) and one positively (Gs). The latter is a candidate for the serotonin receptor that mediates phase advances in circadian rhythms...Texas (Sutcliffe, Erlander) Concepts in Biology and Medicine, Scripps Faculty Lecture Series (Sutcliffe) Advances in the Pharmacology and Clinical

The Validity and Reliability of Rhythm Measurements in Automatically Scoring the English Rhythm Proficiency of Chinese EFL Learners

ERIC Educational Resources Information Center

Chen, Jin; Lin, Jianghao; Li, Xinguang

2015-01-01

This article aims to find out the validity of rhythm measurements to capture the rhythmic features of Chinese English. Besides, the reliability of the valid rhythm measurements applied in automatically scoring the English rhythm proficiency of Chinese EFL learners is also explored. Thus, two experiments were carried out. First, thirty students of…

Speech rhythm: a metaphor?

PubMed Central

Nolan, Francis; Jeon, Hae-Sung

2014-01-01

Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep ‘prominence gradient’, i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a ‘stress-timed’ language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow ‘syntagmatic contrast’ between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms. PMID:25385774

Cardiac rhythm management devices

PubMed

Stevenson, Irene; Voskoboinik, Alex

2018-05-01

The last decade has seen ongoing evolution and use of cardiac rhythm management devices, including pacemakers, cardiac resynchronisation therapy, implantable cardioverter defibrillators and loop recorders. General practitioners are increasingly involved in follow-up and management of patients with these devices. The aim of this article is to provide an overview of different cardiac rhythm management devices, including their role, implant procedure, post-procedural care, potential complications and follow‑up. We also include practical advice for patients regarding driving, exercise, sexual intimacy and precautions with regards to electromagnetic interference. Cardiac rhythm management devices perform many functions, including bradycardia pacing, monitoring for arrhythmias, cardiac resynchronisation for heart failure, defibrillation and anti-tachycardia pacing for tachyarrhythmias. Concerns regarding potential device-related complications should be discussed with the implanting physician. In the post-implant period, patients with cardiac rhythm management devices can expect to lead normal, active lives. However, caution must occasionally be exercised in certain situations, such as near appliances with electromagnetic interference. Future innovations will move away from transvenous leads to leadless designs with combinations of different components on a 'modular' basis according to the function required.

The evolution of floral biology in basal angiosperms

PubMed Central

Endress, Peter K.

2010-01-01

In basal angiosperms (including ANITA grade, magnoliids, Choranthaceae, Ceratophyllaceae) almost all bisexual flowers are dichogamous (with male and female functions more or less separated in time), and nearly 100 per cent of those are protogynous (with female function before male function). Movements of floral parts and differential early abscission of stamens in the male phase are variously associated with protogyny. Evolution of synchronous dichogamy based on the day/night rhythm and anthesis lasting 2 days is common. In a few clades in Magnoliales and Laurales heterodichogamy has also evolved. Beetles, flies and thrips are the major pollinators, with various degrees of specialization up to large beetles and special flies in some large-flowered Nymphaeaceae, Magnoliaceae, Annonaceae and Aristolochiaceae. Unusual structural specializations are involved in floral biological adaptations (calyptras, inner staminodes, synandria and food bodies, and secretory structures on tepals, stamens and staminodes). Numerous specializations that are common in monocots and eudicots are absent in basal angiosperms. Several families are poorly known in their floral biology. PMID:20047868

Development of cortisol circadian rhythm in infancy.

PubMed

de Weerth, Carolina; Zijl, Robbert H; Buitelaar, Jan K

2003-08-01

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 agree on the age of appearance of the circadian rhythm (varying between 2 weeks till the age of 9 months) nor on whether it is related to the appearance of the sleep-wake circadian rhythm. The object of the present study was to find evidence of the age of appearance of the diurnal rhythm of cortisol and to compare the results obtained by several different analysis methods on a new data set. Cortisol was determined in salival samples of 14 normally developing infants who were followed monthly between the ages of 2 and 5 months. The data were analyzed with several previously published analysis methods as well as with Multilevel Analysis (Hierarchical Linear Modeling). The previously published analysis methods each produced different results when applied to the current data set. Moreover, our results indicate striking differences between young infants in both age of appearance and stability of the diurnal cortisol rhythm. Also, a link was found between the appearance of the sleep-wake circadian rhythm and the cortisol circadian rhythm. An important intraindividual variability in cortisol levels was found even after correcting for the different variables that affect cortisol (i.e. time of sampling, feeding, etc.). Although the choice of analysis method influences the age of appearance obtained, our use of HLM shows that the infants' own variability in onset and stability of the cortisol circadian rhythm greatly contributes to the different results.

RAD-ADAPT: Software for modelling clonogenic assay data in radiation biology.

PubMed

Zhang, Yaping; Hu, Kaiqiang; Beumer, Jan H; Bakkenist, Christopher J; D'Argenio, David Z

2017-04-01

We present a comprehensive software program, RAD-ADAPT, for the quantitative analysis of clonogenic assays in radiation biology. Two commonly used models for clonogenic assay analysis, the linear-quadratic model and single-hit multi-target model, are included in the software. RAD-ADAPT uses maximum likelihood estimation method to obtain parameter estimates with the assumption that cell colony count data follow a Poisson distribution. The program has an intuitive interface, generates model prediction plots, tabulates model parameter estimates, and allows automatic statistical comparison of parameters between different groups. The RAD-ADAPT interface is written using the statistical software R and the underlying computations are accomplished by the ADAPT software system for pharmacokinetic/pharmacodynamic systems analysis. The use of RAD-ADAPT is demonstrated using an example that examines the impact of pharmacologic ATM and ATR kinase inhibition on human lung cancer cell line A549 after ionizing radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

A simple model of circadian rhythms based on dimerization and proteolysis of PER and TIM

PubMed Central

Tyson, JJ; Hong, CI; Thron, CD; Novak, B

1999-01-01

Many organisms display rhythms of physiology and behavior that are entrained to the 24-h cycle of light and darkness prevailing on Earth. Under constant conditions of illumination and temperature, these internal biological rhythms persist with a period close to 1 day ("circadian"), but it is usually not exactly 24 h. Recent discoveries have uncovered stunning similarities among the molecular circuitries of circadian clocks in mice, fruit flies, and bread molds. A consensus picture is coming into focus around two proteins (called PER and TIM in fruit flies), which dimerize and then inhibit transcription of their own genes. Although this picture seems to confirm a venerable model of circadian rhythms based on time-delayed negative feedback, we suggest that just as crucial to the circadian oscillator is a positive feedback loop based on stabilization of PER upon dimerization. These ideas can be expressed in simple mathematical form (phase plane portraits), and the model accounts naturally for several hallmarks of circadian rhythms, including temperature compensation and the per(L) mutant phenotype. In addition, the model suggests how an endogenous circadian oscillator could have evolved from a more primitive, light-activated switch. PMID:20540926

Adoption: biological and social processes linked to adaptation.

PubMed

Grotevant, Harold D; McDermott, Jennifer M

2014-01-01

Children join adoptive families through domestic adoption from the public child welfare system, infant adoption through private agencies, and international adoption. Each pathway presents distinctive developmental opportunities and challenges. Adopted children are at higher risk than the general population for problems with adaptation, especially externalizing, internalizing, and attention problems. This review moves beyond the field's emphasis on adoptee-nonadoptee differences to highlight biological and social processes that affect adaptation of adoptees across time. The experience of stress, whether prenatal, postnatal/preadoption, or during the adoption transition, can have significant impacts on the developing neuroendocrine system. These effects can contribute to problems with physical growth, brain development, and sleep, activating cascading effects on social, emotional, and cognitive development. Family processes involving contact between adoptive and birth family members, co-parenting in gay and lesbian adoptive families, and racial socialization in transracially adoptive families affect social development of adopted children into adulthood.

Quantifying the Relative Contributions of Divisive and Subtractive Feedback to Rhythm Generation

PubMed Central

Tabak, Joël; Rinzel, John; Bertram, Richard

2011-01-01

Biological systems are characterized by a high number of interacting components. Determining the role of each component is difficult, addressed here in the context of biological oscillations. Rhythmic behavior can result from the interplay of positive feedback that promotes bistability between high and low activity, and slow negative feedback that switches the system between the high and low activity states. Many biological oscillators include two types of negative feedback processes: divisive (decreases the gain of the positive feedback loop) and subtractive (increases the input threshold) that both contribute to slowly move the system between the high- and low-activity states. Can we determine the relative contribution of each type of negative feedback process to the rhythmic activity? Does one dominate? Do they control the active and silent phase equally? To answer these questions we use a neural network model with excitatory coupling, regulated by synaptic depression (divisive) and cellular adaptation (subtractive feedback). We first attempt to apply standard experimental methodologies: either passive observation to correlate the variations of a variable of interest to system behavior, or deletion of a component to establish whether a component is critical for the system. We find that these two strategies can lead to contradictory conclusions, and at best their interpretive power is limited. We instead develop a computational measure of the contribution of a process, by evaluating the sensitivity of the active (high activity) and silent (low activity) phase durations to the time constant of the process. The measure shows that both processes control the active phase, in proportion to their speed and relative weight. However, only the subtractive process plays a major role in setting the duration of the silent phase. This computational method can be used to analyze the role of negative feedback processes in a wide range of biological rhythms. PMID:21533065

A Norway spruce FLOWERING LOCUS T homolog is implicated in control of growth rhythm in conifers.

PubMed

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.

A possible correlation between performance IQ, visuomotor adaptation ability and mu suppression.

PubMed

Anwar, Muhammad Nabeel; Navid, Muhammad Samran; Khan, Mushtaq; Kitajo, Keiichi

2015-04-07

Psychometric, anatomical and functional brain studies suggest that individuals differ in the way that they perceive and analyze information and strategically control and execute movements. Inter-individual differences are also observed in neural correlates of specific and general cognitive ability. As a result, some individuals perceive and adapt to environmental conditions and perform motor activities better than others. The aim of this study was to identify a common factor that predicts adaptation of a reaching movement to a visual perturbation and suppression of movement-related brain activity (mu rhythms). Twenty-eight participants participated in two different experiments designed to evaluate visuomotor adaptation and mu suppression ability. Performance intelligence quotient (IQ) was assessed using the revised Wechsler Adult Intelligence Scale. Performance IQ predicted adaptation index of visuomotor performance (r=0.43, p=0.02) and suppression of mu rhythms (r=-0.59; p<0.001). Participants with high performance IQ were faster at adapting to a visuomotor perturbation and better at suppressing mu activity than participants with low performance IQ. We found a possible link between performance IQ and mu suppression, and performance IQ and the initial rate of adaptation. Individuals with high performance IQ were better in suppressing mu rhythms and were quicker at associating motor command and required movement than individuals with low performance IQ. Copyright © 2015 Elsevier B.V. All rights reserved.

Melatonin and circadian rhythms in autism: Case report.

PubMed

Zuculo, Gabriela Melloni; Gonçalves, Bruno S B; Brittes, Clay; Menna-Barreto, Luiz; Pinato, Luciana

2017-01-01

Among the most co-occurring conditions in autism spectrum disorders (ASD), there are sleep disorders which may exacerbate associated behavioral disorders and lead to intensification of existing autistic symptoms. Several studies investigating the use of melatonin in the treatment of sleep disorders in ASD have shown comparative efficiency in sleep with little or no side effects. Here we report a case of ASD with non-24-hour rhythm and the effect of melatonin in circadian parameters by actigraphy. Visual analysis of the first 10 days recorded and the periodogram suggest that this patient showed a non-24-hour rhythm. This ASD subject showed before melatonin administration an activity/rest rhythm lower than 24 hours. The results show that melatonin increased approximately 4.7 times the regularity of circadian activity rhythm and resting staying on average between 00:00 and 06:00 and showed positive effects in improving the quality of sleep and behavior. So, the actigraphy showed an ASD subject with a non-24-hour activity/rest rhythm which changed this rhythm to a 24-hour rhythm after melatonin administration. This result reinforces the prospect of therapy with melatonin for synchronization (increased regularity) of endogenous rhythms and improve sleep quality and hence behavior and indicates the actigraphy as a choice tool to characterize several parameters of the activity/rest rhythm of ASD individuals.

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

PubMed Central

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

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

PubMed

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.

Speech rhythm: a metaphor?

PubMed

Nolan, Francis; Jeon, Hae-Sung

2014-12-19

Is speech rhythmic? In the absence of evidence for a traditional view that languages strive to coordinate either syllables or stress-feet with regular time intervals, we consider the alternative that languages exhibit contrastive rhythm subsisting merely in the alternation of stronger and weaker elements. This is initially plausible, particularly for languages with a steep 'prominence gradient', i.e. a large disparity between stronger and weaker elements; but we point out that alternation is poorly achieved even by a 'stress-timed' language such as English, and, historically, languages have conspicuously failed to adopt simple phonological remedies that would ensure alternation. Languages seem more concerned to allow 'syntagmatic contrast' between successive units and to use durational effects to support linguistic functions than to facilitate rhythm. Furthermore, some languages (e.g. Tamil, Korean) lack the lexical prominence which would most straightforwardly underpin prominence of alternation. We conclude that speech is not incontestibly rhythmic, and may even be antirhythmic. However, its linguistic structure and patterning allow the metaphorical extension of rhythm in varying degrees and in different ways depending on the language, and it is this analogical process which allows speech to be matched to external rhythms. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

The Pathophysiologic Role of Disrupted Circadian and Neuroendocrine Rhythms in Breast Carcinogenesis.

PubMed

Ball, Lonnele J; Palesh, Oxana; Kriegsfeld, Lance J

2016-10-01

Most physiological processes in the brain and body exhibit daily (circadian) rhythms coordinated by an endogenous master clock located in the suprachiasmatic nucleus of the hypothalamus that are essential for normal health and functioning. Exposure to sunlight during the day and darkness at night optimally entrains biological rhythms to promote homeostasis and human health. Unfortunately, a major consequence of the modern lifestyle is increased exposure to sun-free environments during the day and artificial lighting at night. Additionally, behavioral disruptions to circadian rhythms (ie, repeated transmeridian flights, night or rotating shift work, or sleep disturbances) have a profound influence on health and have been linked to a number of pathological conditions, including endocrine-dependent cancers. Specifically, night shift work has been identified as a significant risk factor for breast cancer in industrialized countries. Several mechanisms have been proposed by which shift work-induced circadian disruptions promote cancer. In this review, we examine the importance of the brain-body link through which circadian disruptions contribute to endocrine-dependent diseases, including breast carcinogenesis, by negatively impacting neuroendocrine and neuroimmune cells, and we consider preventive measures directed at maximizing circadian health.

The Pathophysiologic Role of Disrupted Circadian and Neuroendocrine Rhythms in Breast Carcinogenesis

PubMed Central

Ball, Lonnele J.; Palesh, Oxana

2016-01-01

Most physiological processes in the brain and body exhibit daily (circadian) rhythms coordinated by an endogenous master clock located in the suprachiasmatic nucleus of the hypothalamus that are essential for normal health and functioning. Exposure to sunlight during the day and darkness at night optimally entrains biological rhythms to promote homeostasis and human health. Unfortunately, a major consequence of the modern lifestyle is increased exposure to sun-free environments during the day and artificial lighting at night. Additionally, behavioral disruptions to circadian rhythms (ie, repeated transmeridian flights, night or rotating shift work, or sleep disturbances) have a profound influence on health and have been linked to a number of pathological conditions, including endocrine-dependent cancers. Specifically, night shift work has been identified as a significant risk factor for breast cancer in industrialized countries. Several mechanisms have been proposed by which shift work-induced circadian disruptions promote cancer. In this review, we examine the importance of the brain-body link through which circadian disruptions contribute to endocrine-dependent diseases, including breast carcinogenesis, by negatively impacting neuroendocrine and neuroimmune cells, and we consider preventive measures directed at maximizing circadian health. PMID:27712099

Experiment K-7-35: Circadian Rhythms and Temperature Regulation During Spaceflight. Part 1; Circadian Rhythms and Temperature Regulation

NASA Technical Reports Server (NTRS)

Fuller, C. A.; Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.

1994-01-01

Mammals have developed the ability to adapt to most variations encountered in their everyday environment. For example, homeotherms have developed the ability to maintain the internal cellular environment at a relatively constant temperature. Also, in order to compensate for temporal variations in the terrestrial environment, the circadian timing system has evolved. However, throughout the evolution of life on earth, living organisms have been exposed to the influence of an unvarying level of earth's gravity. As a result changes in gravity produce adaptive responses which are not completely understood. In particular, spaceflight has pronounced effects on various physiological and behavioral systems. Such systems include body temperature regulation and circadian rhythms. This program has examined the influence of microgravity on temperature regulation and circadian timekeeping systems in Rhesus monkeys. Animals flown on the Soviet Biosatellite, COSMOS 2044, were exposed to 14 days of microgravity while constantly monitoring the circadian patterns temperature regulation, heart rate and activity. This experiment has extended our previous observations from COSMOS 1514, as well as providing insights into the physiological mechanisms that produce these changes.

Adaptive neural coding: from biological to behavioral decision-making

PubMed Central

Louie, Kenway; Glimcher, Paul W.; Webb, Ryan

2015-01-01

Empirical decision-making in diverse species deviates from the predictions of normative choice theory, but why such suboptimal behavior occurs is unknown. Here, we propose that deviations from optimality arise from biological decision mechanisms that have evolved to maximize choice performance within intrinsic biophysical constraints. Sensory processing utilizes specific computations such as divisive normalization to maximize information coding in constrained neural circuits, and recent evidence suggests that analogous computations operate in decision-related brain areas. These adaptive computations implement a relative value code that may explain the characteristic context-dependent nature of behavioral violations of classical normative theory. Examining decision-making at the computational level thus provides a crucial link between the architecture of biological decision circuits and the form of empirical choice behavior. PMID:26722666

Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate.

PubMed

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

Wheel running improves REM sleep and attenuates stress-induced flattening of diurnal rhythms in F344 rats.

PubMed

Thompson, Robert S; Roller, Rachel; Greenwood, Benjamin N; Fleshner, Monika

2016-05-01

Regular physical activity produces resistance to the negative health consequences of stressor exposure. One way that exercise may confer stress resistance is by reducing the impact of stress on diurnal rhythms and sleep; disruptions of which contribute to stress-related disease including mood disorders. Given the link between diurnal rhythm disruptions and stress-related disorders and that exercise both promotes stress resistance and is a powerful non-photic biological entrainment cue, we tested if wheel running could reduce stress-induced disruptions of sleep/wake behavior and diurnal rhythms. Adult, male F344 rats with or without access to running wheels were instrumented for biotelemetric recording of diurnal rhythms of locomotor activity, heart rate, core body temperature (CBT), and sleep (i.e. REM, NREM, and WAKE) in the presence of a 12 h light/dark cycle. Following 6 weeks of sedentary or exercise conditions, rats were exposed to an acute stressor known to disrupt diurnal rhythms and produce behaviors associated with mood disorders. Prior to stressor exposure, exercise rats had higher CBT, more locomotor activity during the dark cycle, and greater %REM during the light cycle relative to sedentary rats. NREM and REM sleep were consolidated immediately following peak running to a greater extent in exercise, compared to sedentary rats. In response to stressor exposure, exercise rats expressed higher stress-induced hyperthermia than sedentary rats. Stressor exposure disrupted diurnal rhythms in sedentary rats; and wheel running reduced these effects. Improvements in sleep and reduced diurnal rhythm disruptions following stress could contribute to the health promoting and stress protective effects of exercise.

Wheel Running Improves REM Sleep and Attenuates Stress-induced Flattening of Diurnal Rhythms in F344 Rats

PubMed Central

Thompson, Robert S.; Roller, Rachel; Greenwood, Benjamin N.; Fleshner, Monika

2016-01-01

Regular physical activity produces resistance to the negative health consequences of stressor exposure. One way that exercise may confer stress resistance is by reducing the impact of stress on diurnal rhythms and sleep; disruptions of which contribute to stress-related disease including mood disorders. Given the link between diurnal rhythm disruptions and stress-related disorders and that exercise both promotes stress resistance and is a powerful non-photic biological entrainment cue, we tested if wheel running could reduce stress-induced disruptions of sleep/wake behavior and diurnal rhythms. Adult, male F344 rats with or without access to running wheels were instrumented for biotelemetric recording of diurnal rhythms of locomotor activity, heart rate, core body temperature (CBT), and sleep (i.e. REM, NREM, and WAKE) in the presence of a 12hr light/dark cycle. Following 6 weeks of sedentary or exercise conditions, rats were exposed to an acute stressor known to disrupt diurnal rhythms and produce behaviors associated with mood disorders. Prior to stressor exposure, exercise rats had higher CBT, more locomotor activity during the dark cycle, and greater %REM during the light cycle relative to sedentary rats. NREM and REM sleep were consolidated immediately following peak running to a greater extent in exercise, compared to sedentary rats. In response to stressor exposure, exercise rats expressed higher stress-induced hyperthermia than sedentary rats. Stressor exposure disrupted diurnal rhythms in sedentary rats; and wheel running reduced these effects. Improvements in sleep and reduced diurnal rhythm disruptions following stress could contribute to the health promoting and stress protective effects of exercise. PMID:27124542

Circadian Rhythms and Sleep in Drosophila melanogaster

PubMed Central

Dubowy, Christine; Sehgal, Amita

2017-01-01

The advantages of the model organism Drosophila melanogaster, including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful

Melatonin, The Pineal Gland and Circadian Rhythms

DTIC Science & Technology

1992-04-30

physiological rhythms including locomotion, sleep/wake, thermoregulation , car- diovascular function and many endocrine processes. Among the rhythms under SCN...control of a wide array of behavioral and physiological rhythms including locomotion, sleep/wake, thermoregulation , cardiovascular function and many... reptiles and birds, overt rhythmicity results from the integration of multiple circadian oscillators within the pineal gland, eyes and the presumed

Differential short-term memorisation for vocal and instrumental rhythms.

PubMed

Klyn, Niall A M; Will, Udo; Cheong, Yong-Jeon; Allen, Erin T

2016-07-01

This study explores differential processing of vocal and instrumental rhythms in short-term memory with three decision (same/different judgments) and one reproduction experiment. In the first experiment, memory performance declined for delayed versus immediate recall, with accuracy for the two rhythms being affected differently: Musicians performed better than non-musicians on clapstick but not on vocal rhythms, and musicians were better on vocal rhythms in the same than in the different condition. Results for the second experiment showed that concurrent sub-vocal articulation and finger-tapping differentially affected the two rhythms and same/different decisions, but produced no evidence for articulatory loop involvement in delayed decision tasks. In a third experiment, which tested rhythm reproduction, concurrent sub-vocal articulation decreased memory performance, with a stronger deleterious effect on the reproduction of vocal than of clapstick rhythms. This suggests that the articulatory loop may only be involved in delayed reproduction not in decision tasks. The fourth experiment tested whether differences between filled and empty rhythms (continuous vs. discontinuous sounds) can explain the different memorisation of vocal and clapstick rhythms. Though significant differences were found for empty and filled instrumental rhythms, the differences between vocal and clapstick can only be explained by considering additional voice specific features.

Wavelet-based analysis of circadian behavioral rhythms.

PubMed

Leise, Tanya L

2015-01-01

The challenging problems presented by noisy biological oscillators have led to the development of a great variety of methods for accurately estimating rhythmic parameters such as period and amplitude. This chapter focuses on wavelet-based methods, which can be quite effective for assessing how rhythms change over time, particularly if time series are at least a week in length. These methods can offer alternative views to complement more traditional methods of evaluating behavioral records. The analytic wavelet transform can estimate the instantaneous period and amplitude, as well as the phase of the rhythm at each time point, while the discrete wavelet transform can extract the circadian component of activity and measure the relative strength of that circadian component compared to those in other frequency bands. Wavelet transforms do not require the removal of noise or trend, and can, in fact, be effective at removing noise and trend from oscillatory time series. The Fourier periodogram and spectrogram are reviewed, followed by descriptions of the analytic and discrete wavelet transforms. Examples illustrate application of each method and their prior use in chronobiology is surveyed. Issues such as edge effects, frequency leakage, and implications of the uncertainty principle are also addressed. © 2015 Elsevier Inc. All rights reserved.

PubMed Central

De Koninck, J

1991-01-01

Because of their influence on psychological adaptation, biological rhythms associated with sleep have received growing attention during the last two decades. We are presenting an outline of (1) the ultradian rhythms of rapid-eye-movement (REM) sleep and of slow wave sleep (SWS), (2) the circadian rhythms of sleep/wake, body temperature and melatonine secretion, and (3) the infradian rhythms of the menstrual cycle and seasonal affective disorders emphasizing their importance in psychological adaptation. Particular attention is given to the consequences of the desynchronization of the circadian phase of sleeping and waking with that of core body temperature observed in the cases of abrupt time zone changes, shift work and some forms of insomnia and depression. New methods of intervention, such as the use of exposure to bright lights are discussed. A case is made for increased attention to a new form of hygiene, that of the biological rhythms associated with sleeping and waking. PMID:1958644

[Research advances in circadian rhythm of epileptic seizures].

PubMed

Yang, Wen-Qi; Li, Hong

2017-01-01

The time phase of epileptic seizures has attracted more and more attention. Epileptic seizures have their own circadian rhythm. The same type of epilepsy has different seizure frequencies in different time periods and states (such as sleeping/awakening state and natural day/night cycle). The circadian rhythm of epileptic seizures has complex molecular and endocrine mechanisms, and currently there are several hypotheses. Clarification of the circadian rhythm of epileptic seizures and prevention and administration according to such circadian rhythm can effectively control seizures and reduce the adverse effects of drugs. The research on the circadian rhythm of epileptic seizures provides a new idea for the treatment of epilepsy.

The sensory-motor theory of rhythm and beat induction 20 years on: a new synthesis and future perspectives

PubMed Central

Todd, Neil P. M.; Lee, Christopher S.

2015-01-01

Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999). A neurological substrate was proposed which might form the biological basis of the theory (Todd et al., 2002). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a,b). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the “dance habit”; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research. PMID:26379522

The sensory-motor theory of rhythm and beat induction 20 years on: a new synthesis and future perspectives.

PubMed

Todd, Neil P M; Lee, Christopher S

2015-01-01

Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999). A neurological substrate was proposed which might form the biological basis of the theory (Todd et al., 2002). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a,b). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the "dance habit"; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research.

Adaptation to Experimental Jet-Lag in R6/2 Mice despite Circadian Dysrhythmia

PubMed Central

Wood, Nigel I.; McAllister, Catherine J.; Cuesta, Marc; Aungier, Juliet; Fraenkel, Eloise; Morton, A. Jennifer

2013-01-01

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 in R6/2 mice. Mice were subjected to four x 4 hour advances in light onset. R6/2 mice adapted to phase advances, although angles of entrainment increased with age. A second cohort was subjected to a jet-lag paradigm (6 hour delay or advance in light onset, then reversal after 2 weeks). R6/2 mice adapted to the original shift, but could not adjust accurately to the reversal. Interestingly, phase shifts ameliorated the circadian rhythm breakdown seen in R6/2 mice under normal LD conditions. Our previous finding that the circadian period (tau) of 16 week old R6/2 mice shortens to approximately 23 hours may explain how they adapt to phase advances and maintain regular circadian rhythms. We tested this using a 23 hour period light/dark cycle. R6/2 mice entrained to this cycle, but onsets of activity continued to advance, and circadian rhythms still disintegrated. Therefore, the beneficial effects of phase-shifting are not due solely to the light cycle being closer to the tau of the mice. Our data show that R6/2 mice can adapt to changes in the LD schedule, even beyond the age when their circadian rhythms would normally disintegrate. Nevertheless, they show abnormal responses to changes in light cycles. These might be caused by a shortened tau, impaired photic re-synchronization, impaired light detection and/or reduced masking by evening light. If similar abnormalities are present in HD patients, they may suffer exaggerated jet-lag. Since the underlying molecular clock mechanism remains intact, light may be a useful treatment for circadian dysfunction in HD. PMID:23390510

Acquisition of speech rhythm in first language.

PubMed

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.

Review article: chronobiology: influence of circadian rhythms on the therapy of severe pain.

PubMed

Junker, Uwe; Wirz, Stefan

2010-06-01

Modern pain therapy widely follows the WHO (World Health Organization) guidelines using a three-step 'ladder' for pain relief. This escalating step scheme includes the administration in the order nonopioids, mild opioids and strong opioids, and adjuvants at any step. Analgesics should be given 'by the clock' rather than 'on demand'. However, the chronobiological parameters circadian pain rhythm, circadian efficacy of analgesics, and individual circadian need for analgesics are to be considered. The results of a multitude of studies in chronobiology are not consistent. Therefore, further studies with standardized protocols are needed that allow to assign more consistent rhythms to diseases, pain causes, and analgesic efficacy of opioids. In many cases, each patient perceives pain and its intensity individually during the time of day. By administration of analgesics over a constant or continuous dosage time fluctuations in pain perception and the outcomes of many studies in chronobiology are ignored that prove the influence of biological rhythms on the pharmacokinetic and pharmacodynamic aspects of analgesics. As different types of pain show different rhythms (highest pain intensities arising at different times of the day) analgesics should be dosed flexibly. It is also very important that drug therapy can be adjusted individually to the pain rhythm of the patient as well as to the type and cause of pain. In severe pain, therapy should be particularly careful. A flexible dosage depending on pain intensity and rapid dose adjustment are essentials of a modern pain therapy. Therefore, opioids that are flexible to use are better suited to treat the individual pain of the patient than rigid modified release oral or transdermal systems.

Evaluation of regression-based 3-D shoulder rhythms.

PubMed

Xu, Xu; Dickerson, Clark R; Lin, Jia-Hua; McGorry, Raymond W

2016-08-01

The movements of the humerus, the clavicle, and the scapula are not completely independent. The coupled pattern of movement of these bones is called the shoulder rhythm. To date, multiple studies have focused on providing regression-based 3-D shoulder rhythms, in which the orientations of the clavicle and the scapula are estimated by the orientation of the humerus. In this study, six existing regression-based shoulder rhythms were evaluated by an independent dataset in terms of their predictability. The datasets include the measured orientations of the humerus, the clavicle, and the scapula of 14 participants over 118 different upper arm postures. The predicted orientations of the clavicle and the scapula were derived from applying those regression-based shoulder rhythms to the humerus orientation. The results indicated that none of those regression-based shoulder rhythms provides consistently more accurate results than the others. For all the joint angles and all the shoulder rhythms, the RMSE are all greater than 5°. Among those shoulder rhythms, the scapula lateral/medial rotation has the strongest correlation between the predicted and the measured angles, while the other thoracoclavicular and thoracoscapular bone orientation angles only showed a weak to moderate correlation. Since the regression-based shoulder rhythm has been adopted for shoulder biomechanical models to estimate shoulder muscle activities and structure loads, there needs to be further investigation on how the predicted error from the shoulder rhythm affects the output of the biomechanical model. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Biological Bases for Radiation Adaptive Responses in the Lung

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott, Bobby R.; Lin, Yong; Wilder, Julie

2015-03-01

Our main research objective was to determine the biological bases for low-dose, radiation-induced adaptive responses in the lung, and use the knowledge gained to produce an improved risk model for radiation-induced lung cancer that accounts for activated natural protection, genetic influences, and the role of epigenetic regulation (epiregulation). Currently, low-dose radiation risk assessment is based on the linear-no-threshold hypothesis, which now is known to be unsupported by a large volume of data.

HCN4-Overexpressing Mouse Embryonic Stem Cell-Derived Cardiomyocytes Generate a New Rapid Rhythm in Rats with Bradycardia.

PubMed

Saito, Yukihiro; Nakamura, Kazufumi; Yoshida, Masashi; Sugiyama, Hiroki; Takano, Makoto; Nagase, Satoshi; Morita, Hiroshi; Kusano, Kengo F; Ito, Hiroshi

2018-05-30

A biological pacemaker is expected to solve the persisting problems of an artificial cardiac pacemaker including short battery life, lead breaks, infection, and electromagnetic interference. We previously reported HCN4 overexpression enhances pacemaking ability of mouse embryonic stem cell-derived cardiomyocytes (mESC-CMs) in vitro. However, the effect of these cells on bradycardia in vivo has remained unclear. Therefore, we transplanted HCN4-overexpressing mESC-CMs into bradycardia model animals and investigated whether they could function as a biological pacemaker. The rabbit Hcn4 gene was transfected into mouse embryonic stem cells and induced HCN4-overexpressing mESC-CMs. Non-cardiomyocytes were removed under serum/glucose-free and lactate-supplemented conditions. Cardiac balls containing 5 × 10 3 mESC-CMs were made by using the hanging drop method. One hundred cardiac balls were injected into the left ventricular free wall of complete atrioventricular block (CAVB) model rats. Heart beats were evaluated using an implantable telemetry system 7 to 30 days after cell transplantation. The result showed that ectopic ventricular beats that were faster than the intrinsic escape rhythm were often observed in CAVB model rats transplanted with HCN4-overexpressing mESC-CMs. On the other hand, the rats transplanted with non-overexpressing mESC-CMs showed sporadic single premature ventricular contraction but not sustained ectopic ventricular rhythms. These results indicated that HCN4-overexpressing mESC-CMs produce rapid ectopic ventricular rhythms as a biological pacemaker.

Vitamin B12 treatment for sleep-wake rhythm disorders.

PubMed

Okawa, M; Mishima, K; Nanami, T; Shimizu, T; Iijima, S; Hishikawa, Y; Takahashi, K

1990-02-01

Vitamin B12 (VB12) was administered to two patients suffering for many years from different sleep-wake rhythm disorders. One patient was a 15-year-old blind girl suffering from a free-running sleep-wake rhythm (hypernychthemeral syndrome) with a period of about 25 h. In spite of repeated trials to entrain her sleep-wake cycle to the environmental 24-h rhythm, her free-running rhythm persisted for about 13 years. When she was 14 years old, administration of VB12 per os was started at the daily dose of 1.5 mg t.i.d. Shortly thereafter, her sleep-wake rhythm was entrained to the environmental 24-h rhythm, and her 24-h sleep-wake rhythm was maintained while she was on the medication. Within 2 months of the withholding of VB12, her free-running sleep-wake rhythm reappeared. The VB12 level in the serum was within the normal range both before and after treatment. The other patient was a 55-year-old man suffering from delayed sleep phase syndrome since 18 years of age. After administration of VB12 at the daily doses of 1.5 mg, his sleep-wake rhythm disorder was improved. The good therapeutic effect lasted for more than 6 months while he was on the medication.

The effect of blue-blocking intraocular lenses on circadian biological rhythm: protocol for a randomised controlled trial (CLOCK-IOL colour study).

PubMed

Nishi, Tomo; Saeki, Keigo; Obayashi, Kenji; Miyata, Kimie; Tone, Nobuhiro; Tsujinaka, Hiroki; Yamashita, Mariko; Masuda, Naonori; Mizusawa, Yutarou; Okamoto, Masahiro; Hasegawa, Taiji; Maruoka, Shinji; Ueda, Tetsuo; Kojima, Masashi; Matsuura, Toyoaki; Kurumatani, Norio; Ogata, Nahoko

2015-05-12

Blue light information plays an important role in synchronising internal biological rhythm within the external environment. Circadian misalignment is associated with the increased risk of sleep disturbance, obesity, diabetes mellitus, depression, ischaemic heart disease, stroke and cancer. Meanwhile, blue light causes photochemical damage to the retina, and may be associated with age-related macular degeneration (AMD). At present, clear intraocular lenses (IOLs) and blue-blocking IOLs are both widely used for cataract surgery; there is currently a lack of randomised controlled trials to determine whether clear or blue-blocking IOLs should be used. This randomised controlled trial will recruit 1000 cataract patients and randomly allocate them to receive clear IOLs or blue-blocking IOLs in a ratio of 1:1. The primary outcomes are mortality and the incidence of cardiovascular disease, cancer and AMD. Secondary outcomes are fasting plasma glucose, triglycerides, cholesterol, glycated haemoglobin, sleep quality, daytime sleepiness depressive symptoms, light sensitivity, the circadian rhythm of physical activity, wrist skin temperature and urinary melatonin metabolite. Primary outcomes will be followed until 20 years after surgery, and secondary outcomes will be assessed at baseline and 1 year after surgery. Ethical approval has been obtained from the Institutional Review Board of Nara Medical University (No. 13-032). The findings of this study will be communicated to healthcare professionals, participants and the public through peer-reviewed publications, scientific conferences and the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) home page. UMIN000014680. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Daily Rhythms in Mobile Telephone Communication

PubMed Central

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. PMID:26390215

Daily Rhythms in Mobile Telephone Communication.

PubMed

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.

In silico biology of bone modelling and remodelling: adaptation.

PubMed

Gerhard, Friederike A; Webster, Duncan J; van Lenthe, G Harry; Müller, Ralph

2009-05-28

Modelling and remodelling are the processes by which bone adapts its shape and internal structure to external influences. However, the cellular mechanisms triggering osteoclastic resorption and osteoblastic formation are still unknown. In order to investigate current biological theories, in silico models can be applied. In the past, most of these models were based on the continuum assumption, but some questions related to bone adaptation can be addressed better by models incorporating the trabecular microstructure. In this paper, existing simulation models are reviewed and one of the microstructural models is extended to test the hypothesis that bone adaptation can be simulated without particular knowledge of the local strain distribution in the bone. Validation using an experimental murine loading model showed that this is possible. Furthermore, the experimental model revealed that bone formation cannot be attributed only to an increase in trabecular thickness but also to structural reorganization including the growth of new trabeculae. How these new trabeculae arise is still an unresolved issue and might be better addressed by incorporating other levels of hierarchy, especially the cellular level. The cellular level sheds light on the activity and interplay between the different cell types, leading to the effective change in the whole bone. For this reason, hierarchical multi-scale simulations might help in the future to better understand the biomathematical laws behind bone adaptation.

Use of rhythm in acquisition of a computer-generated tracking task.

PubMed

Fulop, A C; Kirby, R H; Coates, G D

1992-08-01

This research assessed whether rhythm aids acquisition of motor skills by providing cues for the timing of those skills. Rhythms were presented to participants visually or visually with auditory cues. It was hypothesized that the auditory cues would facilitate recognition and learning of the rhythms. The three timing principles of rhythms were also explored. It was hypothesized that rhythms that satisfied all three timing principles would be more beneficial in learning a skill than rhythms that did not satisfy the principles. Three groups learned three different rhythms by practicing a tracking task. After training, participants attempted to reproduce the tracks from memory. Results suggest that rhythms do help in learning motor skills but different sets of timing principles explain perception of rhythm in different modalities.

Daily Rhythm in Plasma N-Acetyltryptamine

PubMed Central

Backlund, Peter S.; Urbanski, Henryk F.; Doll, Mark A.; Hein, David W.; Bozinoski, Marjan; Mason, Christopher E.; Coon, Steven L.; Klein, David C.

2017-01-01

Normal physiology undergoes 24-hour changes in function, that include daily rhythms in circulating/hormones, most notably melatonin and cortical steroids. This study focuses on N-acetyltryptamine, a little-studied melatonin receptor mixed agonist/antagonist and the likely evolutionary precursor of melatonin. The central issue addressed was whether N-acetyltryptamine is physiologically present in the circulation. N-Acetyltrypamine was detected by LC-MS/MS in daytime plasma of three different mammals in subnanomolar levels (mean ± SEM: rat, 0.29 ± 0.05 nM, N=5; rhesus macaque, 0.54 ± 0.24 nM, N=4; human, 0.03 ± 0.01 nM, N=32). Twenty four hour blood collections from rhesus macaques revealed a nocturnal increase in plasma N-acetyltryptamine (P < 0.001), which varied from 2- to 15- fold over daytime levels among the four animals studied. Related RNA sequencing studies indicated that the transcript encoding the tryptamine acetylating enzyme arylalkylamine N-acetyltransferase (AANAT) is expressed at similar levels in the rhesus pineal gland and retina, thereby indicating that either tissue could contribute to circulating N-acetyltryptamine. The evidence that N-acetyltryptamine is a physiological component of mammalian blood and exhibits a daily rhythm, together with known effects as a melatonin receptor ligand shifts the status of N-acetyltryptamine from pharmacological tool to that of a candidate for a physiological role. This provides a new opportunity to extend our understanding of 24-hour biology. PMID:28466676

Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate

PubMed Central

Rautner, Helena

2017-01-01

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 confe­derate 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 meaning

Circadian rhythms in effects of hypnotics and sleep inducers.

PubMed

Reinberg, A

1986-01-01

Chronopharmacology involves the investigation of drug effects as a function of biological time and the investigation of drug effects on rhythm characteristics. Three new concepts must be considered: (a) the chronokinetics of a drug, embracing rhythmic (circadian) changes in drug bioavailability (or pharmacokinetics) and its excretion (urinary among others); (b) the chronaesthesia of a biosystem to a drug, i.e. circadian changes in the susceptibility of any biosystem to a drug (including organ systems, parasites, etc.); skin and bronchial chronaesthesia to various agents have been documented in man; and (c) the chronergy of a drug, taking into consideration its chronokinetics and the chronaesthesia of the involved organismic biosystems. The term chronergy includes rhythmic changes in the overall effects and in the effectiveness of some drugs. Clinical chronopharmacology is useful for solving problems of drug optimization, i.e. enhancing the desired efficiency of a drug and reducing its undesired effects. Circadian rhythms can be demonstrated in various effects of drugs on sleep, anaesthesia and related processes. For example, in the rat the duration of sleep induced by substances such as pentobarbital, hexobarbital, Althesin (alphaxadone and alphadoline in castor oil) is circadian system stage-dependent. Time-dependent changes of liver enzymes (e.g. hexobarbital oxidase) play a role in these circadian rhythms. The clinical chronopharmacokinetics of benzodiazepines have been documented in man. Chronopharmacologic methods can be used to study desired and undesired hypnotic effects of substances. Such is the case of new antihistamines (anti-H1), which do not induce sleepiness, in either acute or chronic administration. Pertinent also is the problem of intolerance to shift-work. Intolerant shift-workers are subject to internal desynchronization between at least two rhythms (e.g. activity-rest cycle and body temperature). Clinically these workers suffer from sleep

Adapting viral safety assurance strategies to continuous processing of biological products.

PubMed

Johnson, Sarah A; Brown, Matthew R; Lute, Scott C; Brorson, Kurt A

2017-01-01

There has been a recent drive in commercial large-scale production of biotechnology products to convert current batch mode processing to continuous processing manufacturing. There have been reports of model systems capable of adapting and linking upstream and downstream technologies into a continuous manufacturing pipeline. However, in many of these proposed continuous processing model systems, viral safety has not been comprehensively addressed. Viral safety and detection is a highly important and often expensive regulatory requirement for any new biological product. To ensure success in the adaption of continuous processing to large-scale production, there is a need to consider the development of approaches that allow for seamless incorporation of viral testing and clearance/inactivation methods. In this review, we outline potential strategies to apply current viral testing and clearance/inactivation technologies to continuous processing, as well as modifications of existing unit operations to ensure the successful integration of viral clearance into the continuous processing of biological products. Biotechnol. Bioeng. 2017;114: 21-32. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Heterogeneity induces rhythms of weakly coupled circadian neurons

NASA Astrophysics Data System (ADS)

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

2016-02-01

The main clock located in the suprachiasmatic nucleus (SCN) regulates circadian rhythms in mammals. The SCN is composed of approximately twenty thousand heterogeneous self-oscillating neurons, that have intrinsic periods varying from 22 h to 28 h. They are coupled through neurotransmitters and neuropeptides to form a network and output a uniform periodic rhythm. Previous studies found that the heterogeneity of the neurons leads to attenuation of the circadian rhythm with strong cellular coupling. In the present study, we investigate the heterogeneity of the neurons and of the network in the condition of constant darkness. Interestingly, we found that the heterogeneity of weakly coupled neurons enables them to oscillate and strengthen the circadian rhythm. In addition, we found that the period of the SCN network increases with the increase of the degree of heterogeneity. As the network heterogeneity does not change the dynamics of the rhythm, our study shows that the heterogeneity of the neurons is vitally important for rhythm generation in weakly coupled systems, such as the SCN, and it provides a new method to strengthen the circadian rhythm, as well as an alternative explanation for differences in free running periods between species in the absence of the daily cycle.

Recent advances in rhythm control for atrial fibrillation

PubMed Central

Bond, Richard; Olshansky, Brian; Kirchhof, Paulus

2017-01-01

Atrial fibrillation (AF) remains a difficult management problem. The restoration and maintenance of sinus rhythm—rhythm control therapy—can markedly improve symptoms and haemodynamics for patients who have paroxysmal or persistent AF, but some patients fare well with rate control alone. Sinus rhythm can be achieved with anti-arrhythmic drugs or electrical cardioversion, but the maintenance of sinus rhythm without recurrence is more challenging. Catheter ablation of the AF triggers is more effective than anti-arrhythmic drugs at maintaining sinus rhythm. Whilst pulmonary vein isolation is an effective strategy, other ablation targets are being evaluated to improve sinus rhythm maintenance, especially in patients with chronic forms of AF. Previously extensive ablation strategies have been used for patients with persistent AF, but a recent trial has shown that pulmonary vein isolation without additional ablation lesions is associated with outcomes similar to those of more extensive ablation. This has led to an increase in catheter-based technology to achieve durable pulmonary vein isolation. Furthermore, a combination of anti-arrhythmic drugs and catheter ablation seems useful to improve the effectiveness of rhythm control therapy. Two large ongoing trials evaluate whether a modern rhythm control therapy can improve prognosis in patients with AF. PMID:29043080

Monkey Lipsmacking Develops Like the Human Speech Rhythm

ERIC Educational Resources Information Center

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…

[Semi-automatic defibrillators does not always interpret heart rhythms correctly. Five patients were defibrillated despite non-shockable rhythms].

PubMed

Wangenheim, Burkard; Israelsson, Johan; Lindstaedt, Michael; Carlsson, Jörg

2015-08-04

Automated external defibrillators (AED) have become an important part of the »the chain of survival« in case of sudden cardiac arrest (SCA), where early defibrillation is lifesaving. The American Heart Association demands that AEDs have a specificity of >99 % to recognize normal sinus rhythm and >95 % for the other non-shockable rhythms. Reports on their performance in the field are scarce. We present five cases in which AED recommended shock for apparently non-shockable rhythms. This indicates the necessity to systematically reevaluate AED performance.

A Norway Spruce FLOWERING LOCUS T Homolog Is Implicated in Control of Growth Rhythm in Conifers1[OA

PubMed Central

Gyllenstrand, Niclas; Clapham, David; Källman, Thomas; Lagercrantz, Ulf

2007-01-01

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. PMID:17369429

Melatonin secretion is impaired in women with preeclampsia and an abnormal circadian blood pressure rhythm.

PubMed

Bouchlariotou, Sofia; Liakopoulos, Vassilios; Giannopoulou, Myrto; Arampatzis, Spyridon; Eleftheriadis, Theodoros; Mertens, Peter R; Zintzaras, Elias; Messinis, Ioannis E; Stefanidis, Ioannis

2014-08-01

Non-dipping circadian blood pressure (BP) is a common finding in preeclampsia, accompanied by adverse outcomes. Melatonin plays pivotal role in biological circadian rhythms. This study investigated the relationship between melatonin secretion and circadian BP rhythm in preeclampsia. Cases were women with preeclampsia treated between January 2006 and June 2007 in the University Hospital of Larissa. Volunteers with normal pregnancy, matched for chronological and gestational age, served as controls. Twenty-four hour ambulatory BP monitoring was applied. Serum melatonin and urine 6-sulfatoxymelatonin levels were determined in day and night time samples by enzyme-linked immunoassays. Measurements were repeated 2 months after delivery. Thirty-one women with preeclampsia and 20 controls were included. Twenty-one of the 31 women with preeclampsia were non-dippers. Compared to normal pregnancy, in preeclampsia there were significantly lower night time melatonin (48.4 ± 24.7 vs. 85.4 ± 26.9 pg/mL, p<0.001) levels. Adjustment for circadian BP rhythm status ascribed this finding exclusively to non-dippers (p<0.01). Two months after delivery, in 11 of the 21 non-dippers both circadian BP and melatonin secretion rhythm reappeared. In contrast, in cases with retained non-dipping status (n=10) melatonin secretion rhythm remained impaired: daytime versus night time melatonin (33.5 ± 13.0 vs. 28.0 ± 13.8 pg/mL, p=0.386). Urinary 6-sulfatoxymelatonin levels were, overall, similar to serum melatonin. Circadian BP and melatonin secretion rhythm follow parallel course in preeclampsia, both during pregnancy and, at least 2 months after delivery. Our findings may be not sufficient to implicate a putative therapeutic effect of melatonin, however, they clearly emphasize that its involvement in the pathogenesis of a non-dipping BP in preeclampsia needs intensive further investigation.

Critical time delay of the pineal melatonin rhythm in humans due to weak electromagnetic exposure.

PubMed

Halgamuge, Malka N

2013-08-01

Electromagnetic fields (EMFs) can increase free radicals, activate the stress response and alter enzyme reactions. Intracellular signalling is mediated by free radicals and enzyme kinetics is affected by radical pair recombination rates. The magnetic field component of an external EMF can delay the "recombination rate" of free radical pairs. Magnetic fields thus increase radical life-times in biological systems. Although measured in nanoseconds, this extra time increases the potential to do more damage. Melatonin regulates the body's sleep-wake cycle or circadian rhythm. The World Health Organization (WHO) has confirmed that prolonged alterations in sleep patterns suppress the body's ability to make melatonin. Considerable cancer rates have been attributed to the reduction of melatonin production as a result of jet lag and night shift work. In this study, changes in circadian rhythm and melatonin concentration are observed due to the external perturbation of chemical reaction rates. We further analyze the pineal melatonin rhythm and investigate the critical time delay or maturation time of radical pair recombination rates, exploring the impact of the mRNA degradation rate on the critical time delay. The results show that significant melatonin interruption and changes to the circadian rhythm occur due to the perturbation of chemical reaction rates, as also reported in previous studies. The results also show the influence of the mRNA degradation rate on the circadian rhythm's critical time delay or maturation time. The results support the hypothesis that exposure to weak EMFs via melatonin disruption can adversely affect human health.

24-h activity rhythm and sleep in depressed outpatients.

PubMed

Hori, Hiroaki; Koga, Norie; Hidese, Shinsuke; Nagashima, Anna; Kim, Yoshiharu; Higuchi, Teruhiko; Kunugi, Hiroshi

2016-06-01

Disturbances in sleep and circadian rest-activity rhythms are key features of depression. Actigraphy, a non-invasive method for monitoring motor activity, can be used to objectively assess circadian rest-activity rhythms and sleep patterns. While recent studies have measured sleep and daytime activity of depressed patients using wrist-worn actigraphy, the actigraphic 24-h rest-activity rhythm in depression has not been well documented. We aimed to examine actigraphically measured sleep and circadian rest-activity rhythms in depressed outpatients. Twenty patients with DSM-IV major depressive episode and 20 age- and sex-matched healthy controls participated in this study. Participants completed 7 consecutive days of all-day actigraphic activity monitoring while engaging in usual activities. For sleep parameters, total sleep time, wake after sleep onset, and sleep fragmentation index were determined. Circadian rhythms were estimated by fitting individual actigraphy data to a cosine curve of a 24-h activity rhythm using the cosinor method, which generated three circadian activity rhythm parameters, i.e., MESOR (rhythm-adjusted mean), amplitude, and acrophase. Subjective sleep was also assessed using a sleep diary and the Pittsburgh Sleep Quality Index. Patients showed significantly lower MESOR and more dampened amplitude along with significant sleep disturbances. Logistic regression analysis revealed that lower MESOR and more fragmented sleep emerged as the significant predictors of depression. Correlations between subjectively and actigraphically measured parameters demonstrated the validity of actigraphic measurements. These results indicate marked disturbances in sleep and circadian rest-activity rhythms of depression. By simultaneously measuring sleep and rest-activity rhythm parameters, actigraphy might serve as an objective diagnostic aid for depression. Copyright © 2016 Elsevier Ltd. All rights reserved.

A hypothesis on the biological origins and social evolution of music and dance.

PubMed

Wang, Tianyan

2015-01-01

The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance, and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation for the transposition invariance of music, but also integrates music and dance into a common form-rhythmic movements. Accordingly, investigating the origins of music poses the question: why do humans appreciate rhythmic movements? I suggest that human appreciation of rhythmic movements and rhythmic events developed from the natural selection of organisms adapting to the internal and external rhythmic environments. The perception and production of, as well as synchronization with external and internal rhythms are so vital for an organism's survival and reproduction, that animals have a rhythm-related reward and emotion (RRRE) system. The RRRE system enables the appreciation of rhythmic movements and events, and is integral to the origination of music, dance and speech. The first type of rewards and emotions (rhythm-related rewards and emotions, RRREs) are evoked by music and dance, and have biological and social functions, which in turn, promote the evolution of music, dance and speech. These functions also evoke a second type of rewards and emotions, which I name society-related rewards and emotions (SRREs). The neural circuits of RRREs and SRREs develop in species formation and personal growth, with congenital and acquired characteristics, respectively, namely music is the combination of nature and culture. This hypothesis provides probable selection pressures and outlines the evolution of music, dance, and speech. The links between the Doppler effect and the RRREs and SRREs can be empirically tested, making the current hypothesis scientifically

A hypothesis on the biological origins and social evolution of music and dance

PubMed Central

Wang, Tianyan

2015-01-01

The origins of music and musical emotions is still an enigma, here I propose a comprehensive hypothesis on the origins and evolution of music, dance, and speech from a biological and sociological perspective. I suggest that every pitch interval between neighboring notes in music represents corresponding movement pattern through interpreting the Doppler effect of sound, which not only provides a possible explanation for the transposition invariance of music, but also integrates music and dance into a common form—rhythmic movements. Accordingly, investigating the origins of music poses the question: why do humans appreciate rhythmic movements? I suggest that human appreciation of rhythmic movements and rhythmic events developed from the natural selection of organisms adapting to the internal and external rhythmic environments. The perception and production of, as well as synchronization with external and internal rhythms are so vital for an organism's survival and reproduction, that animals have a rhythm-related reward and emotion (RRRE) system. The RRRE system enables the appreciation of rhythmic movements and events, and is integral to the origination of music, dance and speech. The first type of rewards and emotions (rhythm-related rewards and emotions, RRREs) are evoked by music and dance, and have biological and social functions, which in turn, promote the evolution of music, dance and speech. These functions also evoke a second type of rewards and emotions, which I name society-related rewards and emotions (SRREs). The neural circuits of RRREs and SRREs develop in species formation and personal growth, with congenital and acquired characteristics, respectively, namely music is the combination of nature and culture. This hypothesis provides probable selection pressures and outlines the evolution of music, dance, and speech. The links between the Doppler effect and the RRREs and SRREs can be empirically tested, making the current hypothesis scientifically

Activity in the ferret: oestradiol effects and circadian rhythms

NASA Technical Reports Server (NTRS)

Stockman, E. R.; Albers, H. E.; Baum, M. J.; Wurtman, R. J. (Principal Investigator)

1985-01-01

The present study was conducted to determine whether oestradiol increases activity in the European ferret (Mustela furo), whether this effect is sexually dimorphic, and whether a 24-h rhythm is present in the ferret's daily activity. The activity of male and female adult, postpubertally gonadectomized ferrets was monitored while they were maintained singly on a 13:11 light-dark cycle, before and after implantation with oestradiol-17 beta. Gonadectomized male and female ferrets exhibited equal levels of activity, and neither sex exhibited a significant change in activity following oestradiol implantation. None of the ferrets exhibited a strong circadian rhythm, although weak 24-h rhythms and shorter harmonic rhythms were present. Golden hamsters (Mesocricetus auratus), monitored in an identical manner, exhibited strong circadian rhythms. It was concluded that oestradiol administration may not cause an increase in activity in the ferret, and that this species lacks a strong circadian activity rhythm.

Detecting and Correcting Speech Rhythm Errors

ERIC Educational Resources Information Center

Yurtbasi, Metin

2015-01-01

Every language has its own rhythm. Unlike many other languages in the world, English depends on the correct pronunciation of stressed and unstressed or weakened syllables recurring in the same phrase or sentence. Mastering the rhythm of English makes speaking more effective. Experiments have shown that we tend to hear speech as more rhythmical…

Computational adaptive optics for broadband optical interferometric tomography of biological tissue

NASA Astrophysics Data System (ADS)

Boppart, Stephen A.

2015-03-01

High-resolution real-time tomography of biological tissues is important for many areas of biological investigations and medical applications. Cellular level optical tomography, however, has been challenging because of the compromise between transverse imaging resolution and depth-of-field, the system and sample aberrations that may be present, and the low imaging sensitivity deep in scattering tissues. The use of computed optical imaging techniques has the potential to address several of these long-standing limitations and challenges. Two related techniques are interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO). Through three-dimensional Fourierdomain resampling, in combination with high-speed OCT, ISAM can be used to achieve high-resolution in vivo tomography with enhanced depth sensitivity over a depth-of-field extended by more than an order-of-magnitude, in realtime. Subsequently, aberration correction with CAO can be performed in a tomogram, rather than to the optical beam of a broadband optical interferometry system. Based on principles of Fourier optics, aberration correction with CAO is performed on a virtual pupil using Zernike polynomials, offering the potential to augment or even replace the more complicated and expensive adaptive optics hardware with algorithms implemented on a standard desktop computer. Interferometric tomographic reconstructions are characterized with tissue phantoms containing sub-resolution scattering particles, and in both ex vivo and in vivo biological tissue. This review will collectively establish the foundation for high-speed volumetric cellular-level optical interferometric tomography in living tissues.

Unexpected diversity in socially synchronized rhythms of shorebirds.

PubMed

Bulla, Martin; Valcu, Mihai; Dokter, Adriaan M; Dondua, Alexei G; Kosztolányi, András; Rutten, Anne L; 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, Jos C E W; 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

2016-12-01

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 with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parent's incubation bout varied from 1-19 h, whereas period length-the time in which a parent's probability to incubate cycles once between its highest and lowest value-varied from 6-43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social

Social Rhythm Disrupting Events Increase the Risk of Recurrence among Individuals with Bipolar Disorder

PubMed Central

Levenson, Jessica C.; Wallace, Meredith L.; Anderson, Barbara P.; Kupfer, David J.; Frank, Ellen

2015-01-01

Objectives As outlined in the social zeitgeber hypothesis, social rhythm disrupting (SRD) life events begin a cascade of social and biological rhythm disruption that may lead to the onset of affective episodes in those vulnerable to bipolar disorder. Thus, the study of SRD events is particularly important in individuals with this chronic condition. The purpose of the current study was to evaluate 1) the extent to which social rhythm disrupting life events increased the risk of recurrence of a bipolar mood episode, and 2) whether the social rhythm disruption associated with the event conferred an increased risk of recurrence, after accounting for the level of threat associated with the life event. Methods We examined the effect of SRD events on recurrence during preventative treatment in a sample of 118 patients with bipolar disorder who achieved remission from an acute episode after receiving psychotherapy and pharmacotherapy. Life events were measured with the Bedford College Life Events and Difficulty Schedule and were rated for degree of SRD and threat. Results Time-dependent Cox proportional hazards models showed that that having a higher SRD rating was significantly associated with an increased risk of recurrence, even when accounting for the threat effect of a life event and psychosocial treatment (Hazard Rate = 1.33; 95% CI = 1.04, 1.70; p=0.023). However, this finding fell below conventional levels of statistical significance when accounting for other covariates. Conclusions Our findings lend partial support to the social zeitgeber hypothesis. PMID:26614534

When the rhythm disappears and the mind keeps dancing: sustained effects of attentional entrainment.

PubMed

Trapp, Sabrina; Havlicek, Ondrej; Schirmer, Annett; Keller, Peter E

2018-01-17

Research has demonstrated that the human cognitive system allocates attention most efficiently to a stimulus that occurs in synchrony with an established rhythmic background. However, our environment is dynamic and constantly changing. What happens when rhythms to which our cognitive system adapted disappear? We addressed this question using a visual categorization task comprising emotional and neutral faces. The task was split into three blocks of which the first and the last were completed in silence. The second block was accompanied by an acoustic background rhythm that, for one group of participants, was synchronous with face presentations, and for another group was asynchronous. Irrespective of group, performance improved with background stimulation. Importantly, improved performance extended into the third silent block for the synchronous, but not for the asynchronous group. These data suggest that attentional entrainment resulting from rhythmic environmental regularities disintegrates only gradually after the regularities disappear.

Effects of 9-hour time zone changes on fatigue and circadian rhythms of sleep/wake and core temperature

NASA Technical Reports Server (NTRS)

Gander, P. H.; Myhre, G.; Graeber, R. C.; Andersen, H. T.; Lauber, J. K.

1985-01-01

Physiological and psychological disruptions caused by transmeridian flights may affect the ability of flight crews to meet operational demands. To study these effects, 9 Royal Norwegian Airforces P3-Orion crewmembers flew from Norway to California (-9 hr), and back (+9 hr). Rectal temperature, heart rate and wrist activity were recorded every 2 min, fatigue and mood were rated every 2 hr during the waking day, and logs were kept of sleep times and ratings. Subjects also completed 4 personality inventories. The time-zone shifts produced negative changes in mood which persisted longer after westward flights. Sleep quality (subjective and objective) and duration were slightly disrupted (more after eastward flights). The circadian rhythms of sleep/wake and temperature both completed the 9-hr delay by day 5 in California, although temperature adjusted more slowly. The size of the delay shift was significantly correlated with scores on extraversion and achievement need personality scales. Response to the 9-hr advance were more variable. One subject exhibited a 15-hr delay in his temperature rhythm, and an atypical sleep/nap pattern. On average, the sleep/wake cycle (but not the temperature rhythm), completed the 9-hr advance by the end of the study. Both rhythms adapted more slowly after the eastward flight.

Endogenous thermoregulatory rhythms of squirrel monkeys in thermoneutrality and cold

NASA Technical Reports Server (NTRS)

Robinson, E. L.; Fuller, C. A.

1999-01-01

Whole body heat production (HP) and heat loss (HL) were examined to determine if the free-running circadian rhythm in body temperature (Tb) results from coordinated changes in HP and HL rhythms in thermoneutrality (27 degrees C) as well as mild cold (17 degrees C). Squirrel monkey metabolism (n = 6) was monitored by both indirect and direct calorimetry, with telemetered measurement of Tb and activity. Feeding was also measured. Rhythms of HP, HL, and conductance were tightly coupled with the circadian Tb rhythm at both ambient temperatures (TA). At 17 degrees C, increased HP compensated for higher HL at all phases of the Tb rhythm, resulting in only minor changes to Tb. Parallel compensatory changes of HP and HL were seen at all rhythm phases at both TA. Similar time courses of Tb, HP, and HL in their respective rhythms and the relative stability of Tb during both active and rest periods suggest action of the circadian timing system on Tb set point.

Circadian rhythm in idiopathic normal pressure hydrocephalus.

PubMed

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

The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

PubMed

Sage, Cindy

2015-01-01

The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health

Circadian rhythms in anesthesia and critical care medicine: potential importance of circadian disruptions.

PubMed

Brainard, Jason; Gobel, Merit; Bartels, Karsten; Scott, Benjamin; Koeppen, Michael; Eckle, Tobias

2015-03-01

The rotation of the earth and associated alternating cycles of light and dark--the basis of our circadian rhythms--are fundamental to human biology and culture. However, it was not until 1971 that researchers first began to describe the molecular mechanisms for the circadian system. During the past few years, groundbreaking research has revealed a multitude of circadian genes affecting a variety of clinical diseases, including diabetes, obesity, sepsis, cardiac ischemia, and sudden cardiac death. Anesthesiologists, in the operating room and intensive care units, manage these diseases on a daily basis as they significantly affect patient outcomes. Intriguingly, sedatives, anesthetics, and the intensive care unit environment have all been shown to disrupt the circadian system in patients. In the current review, we will discuss how newly acquired knowledge of circadian rhythms could lead to changes in clinical practice and new therapeutic concepts. © The Author(s) 2014.

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

PubMed

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.

Circadian Rhythm of Ambient Noise Off the Southeast Coast of India

NASA Astrophysics Data System (ADS)

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.

Comparison of synchronization of primate circadian rhythms by light and food

NASA Technical Reports Server (NTRS)

Sulzman, F. M.; Fuller, C. A.; Moore-Ede, M. C.

1978-01-01

It is a well-documented fact that cycles of light and dark (LD) are the major entraining agent or 'zeitgeber' for circadian rhythms and that cycles of eating and fasting (EF) are capable of synchronizing a few circadian rhythms in the squirrel monkey. In this paper, by contrasting how these rhythms are timed by LD and EF cycles, the differential coupling to the oscillating system within adult male squirrel monkeys is examined. The variables measured are the rhythms of drinking, colonic temperature, and urinary potassium and water excretion. Attention is given to a comparison of the reproducibility of the averaged waveforms of the rhythms, the stability of the timing of a phase reference point, and the rate of resynchronization of these rhythms following an abrupt 8-hr phase delay in the zeitgeber. It is shown that the colonic temperature rhythm is more tightly controlled by LD than EF cycles, and that the drinking and urinary rhythms are more tightly coupled to EF than LD cycles.

Development of salivary cortisol circadian rhythm in preterm infants.

PubMed

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

2017-01-01

To investigate at what age preterm infants develop a salivary cortisol circadian rhythm and identify whether it is dependent on gestational age and/or postnatal age. To evaluate whether salivary cortisol circadian rhythm development is related to behavioral regularity. To elucidate salivary cortisol levels in preterm infants during the first year of life. This prospective, longitudinal study included 51 preterm infants. 130 healthy full-term infants served as controls. Monthly salivary cortisol levels were obtained in the morning (07:30-09:30), at noon (10:00-12:00), and in the evening (19:30-21:30), beginning at gestational age week 28-32 and continuing until twelve months corrected age. Behavioral regularity was studied using the Baby Behavior Questionnaire. A salivary cortisol circadian rhythm was established by one month corrected age and persisted throughout the first year. The preterm infants showed a cortisol pattern increasingly more alike the full-term infants as the first year progressed. The preterm infants increase in behavioral regularity with age but no correlation was found between the development of salivary cortisol circadian rhythm and the development of behavior regularity. The time to establish salivary cortisol circadian rhythm differed between preterm and full-term infants according to postnatal age (p = 0.001) and was dependent on gestational age. Monthly salivary cortisol levels for preterm infants from birth until twelve months are presented. Additional findings were that topical corticosteroid medication was associated with higher concentrations of salivary cortisol (p = 0.02) and establishment of salivary cortisol circadian rhythm occurred later in infants treated with topical corticosteroid medication (p = 0.02). Salivary cortisol circadian rhythm is established by one month corrected age in preterm infants. Establishment of salivary cortisol circadian rhythm is related to gestational age rather than to postnatal age. Salivary cortisol

The Features and Training of English Stress and Rhythm

ERIC Educational Resources Information Center

Cai, Cui-yun

2008-01-01

In second language learning, to possess a perfect pronunciation, the importance of stress and rhythm should not be ignored. This articles explores the nature of sentence and word stress as well as rhythm, thus putting forward some feasible ways of training and acquiring a good English stress and rhythm in EFLT (English as Foreign Language…

Circadian Rhythms, Sleep Deprivation, and Human Performance

PubMed Central

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

Environmental synchronizers of squirrel monkey circadian rhythms

NASA Technical Reports Server (NTRS)

Sulzman, F. M.; Fuller, C. A.; Moore-Ede, M. C.

1977-01-01

Various temporal signals in the environment were tested to determine if they could synchronize the circadian timing system of the squirrel monkey (Saimiri sciureus). The influence of cycles of light and dark, eating and fasting, water availability and deprivation, warm and cool temperature, sound and quiet, and social interaction and isolation on the drinking and activity rhythms of unrestrained monkeys was examined. In the absence of other time cues, 24-hr cycles of each of these potential synchronizers were applied for up to 3 wk, and the periods of the monkey's circadian rhythms were examined. Only light-dark cycles and cycles of food availability were shown to be entraining agents, since they were effective in determining the period and phase of the rhythmic variables. In the presence of each of the other environmental cycles, the monkey's circadian rhythms exhibited free-running periods which were significantly different from 24 hr with all possible phase relationships between the rhythms and the environmental cycles being examined.

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

PubMed

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.

Circadian Rhythm in Bipolar Disorder: A review of the literature.

PubMed

Takaesu, Yoshikazu

2018-06-05

Sleep disturbances and circadian rhythm dysfunction have been widely demonstrated in patients with bipolar disorder (BD). Irregularity of the sleep-wake rhythm, eveningness chronotype, abnormality of melatonin secretion, vulnerability of clock genes, and the irregularity of social time cues have also been well-documented in BD. Circadian rhythm dysfunction is prominent in BD compared with that in major depressive disorders, implying that circadian rhythm dysfunction is a trait marker of BD. In the clinical course of BD, the circadian rhythm dysfunctions may act as predictors for the first onset of BD and the relapse of mood episodes. Treatments focusing on sleep disturbances and circadian rhythm dysfunction in combination with pharmacological, psychosocial, and chronobiological treatments are believed to be useful for relapse prevention. Further studies are therefore warranted to clarify the relationship between circadian rhythm dysfunction and the pathophysiology of BD to develop treatment strategies for achieving recovery in BD patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Long-term biological investigations in space.

PubMed

Lotz, R G; Fuchs, H; Bertsche, U

1975-01-01

Missions in space within the next two decades will be of longer duration than those carried out up to the present time, and the effects of such long-term flights on biological organisms are unknown. Results of biological experiments that have been performed to date cannot be extrapolated to results in future flights because of the unknown influence of adaptation over a long period of time. Prior experiments with Axolotl, fishes, and vertebrates by our research team (in part with sounding rockets) showed that these specimens did not appear to be suitable for long-term missions on which minimization of expense, technique, and energy is required. Subsequent investigations have shown the suitability of the leech (Hirudo medicinalis), which consumes blood of mammals up to ten times its own weight (1 g) and can live more than 2 years without further food supply. Emphasis in the experiments with Hirudo medicinalis is placed on metabolic rhythm and motility. Resorption and diffusion in tissue, development, and growth under long-term effects of cosmic proton radiation and zero-gravity are other focal points. The constancy of cellular life in the mature animals is a point in favor of these specimens. We have also taken into account the synergistic effects of the space environment on the problems just mentioned. The life-support system constructed for the leech has been tested successfully in four sounding rocket flights and, on that basis, has been prepared for a long-term mission. Long-term investigations out of the terrestrial biosphere will provide us with information concerning the degree of adaptation of certain physiological and biochemical functions and as to what extent biological readjustment or repair processes can occur under the specific stress conditions of space flight.

Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure

PubMed Central

Bonmati-Carrion, Maria Angeles; Arguelles-Prieto, Raquel; Martinez-Madrid, Maria Jose; Reiter, Russel; Hardeland, Ruediger; Rol, Maria Angeles; Madrid, Juan Antonio

2014-01-01

Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system. PMID:25526564

Protecting the melatonin rhythm through circadian healthy light exposure.

PubMed

Bonmati-Carrion, Maria Angeles; Arguelles-Prieto, Raquel; Martinez-Madrid, Maria Jose; Reiter, Russel; Hardeland, Ruediger; Rol, Maria Angeles; Madrid, Juan Antonio

2014-12-17

Currently, in developed countries, nights are excessively illuminated (light at night), whereas daytime is mainly spent indoors, and thus people are exposed to much lower light intensities than under natural conditions. In spite of the positive impact of artificial light, we pay a price for the easy access to light during the night: disorganization of our circadian system or chronodisruption (CD), including perturbations in melatonin rhythm. Epidemiological studies show that CD is associated with an increased incidence of diabetes, obesity, heart disease, cognitive and affective impairment, premature aging and some types of cancer. Knowledge of retinal photoreceptors and the discovery of melanopsin in some ganglion cells demonstrate that light intensity, timing and spectrum must be considered to keep the biological clock properly entrained. Importantly, not all wavelengths of light are equally chronodisrupting. Blue light, which is particularly beneficial during the daytime, seems to be more disruptive at night, and induces the strongest melatonin inhibition. Nocturnal blue light exposure is currently increasing, due to the proliferation of energy-efficient lighting (LEDs) and electronic devices. Thus, the development of lighting systems that preserve the melatonin rhythm could reduce the health risks induced by chronodisruption. This review addresses the state of the art regarding the crosstalk between light and the circadian system.

Analysis of a Gene Regulatory Cascade Mediating Circadian Rhythm in Zebrafish

PubMed Central

Wang, Haifang; Du, Jiulin; Yan, Jun

2013-01-01

In the study of circadian rhythms, it has been a puzzle how a limited number of circadian clock genes can control diverse aspects of physiology. Here we investigate circadian gene expression genome-wide using larval zebrafish as a model system. We made use of a spatial gene expression atlas to investigate the expression of circadian genes in various tissues and cell types. Comparison of genome-wide circadian gene expression data between zebrafish and mouse revealed a nearly anti-phase relationship and allowed us to detect novel evolutionarily conserved circadian genes in vertebrates. We identified three groups of zebrafish genes with distinct responses to light entrainment: fast light-induced genes, slow light-induced genes, and dark-induced genes. Our computational analysis of the circadian gene regulatory network revealed several transcription factors (TFs) involved in diverse aspects of circadian physiology through transcriptional cascade. Of these, microphthalmia-associated transcription factor a (mitfa), a dark-induced TF, mediates a circadian rhythm of melanin synthesis, which may be involved in zebrafish's adaptation to daily light cycling. Our study describes a systematic method to discover previously unidentified TFs involved in circadian physiology in complex organisms. PMID:23468616

Adaptive walking of a quadrupedal robot based on layered biological reflexes

NASA Astrophysics Data System (ADS)

Zhang, Xiuli; Mingcheng, E.; Zeng, Xiangyu; Zheng, Haojun

2012-07-01

A multiple-legged robot is traditionally controlled by using its dynamic model. But the dynamic-model-based approach fails to acquire satisfactory performances when the robot faces rough terrains and unknown environments. Referring animals' neural control mechanisms, a control model is built for a quadruped robot walking adaptively. The basic rhythmic motion of the robot is controlled by a well-designed rhythmic motion controller(RMC) comprising a central pattern generator(CPG) for hip joints and a rhythmic coupler (RC) for knee joints. CPG and RC have relationships of motion-mapping and rhythmic couple. Multiple sensory-motor models, abstracted from the neural reflexes of a cat, are employed. These reflex models are organized and thus interact with the CPG in three layers, to meet different requirements of complexity and response time to the tasks. On the basis of the RMC and layered biological reflexes, a quadruped robot is constructed, which can clear obstacles and walk uphill and downhill autonomously, and make a turn voluntarily in uncertain environments, interacting with the environment in a way similar to that of an animal. The paper provides a biologically inspired architecture, with which a robot can walk adaptively in uncertain environments in a simple and effective way, and achieve better performances.

Atrial fibrillation and stroke: the evolving role of rhythm control.

PubMed

Patel, Taral K; Passman, Rod S

2013-06-01

Atrial fibrillation (AF) remains a major risk factor for stroke. Unfortunately, clinical trials have failed to demonstrate that a strategy of rhythm control--therapy to maintain normal sinus rhythm (NSR)--reduces stroke risk. The apparent lack of benefit of rhythm control likely reflects the difficulty in maintaining NSR using currently available therapies. However, there are signals from several trials that the presence of NSR is indeed beneficial and associated with better outcomes related to stroke and mortality. Most electrophysiologists feel that as rhythm control strategies continue to improve, the crucial link between rhythm control and stroke reduction will finally be demonstrated. Therefore, AF specialists tend to be aggressive in their attempts to maintain NSR, especially in patients who have symptomatic AF. A step-wise approach from antiarrhythmic drugs to catheter ablation to cardiac surgery is generally used. In select patients, catheter ablation or cardiac surgery may supersede antiarrhythmic drugs. The choice depends on the type of AF, concurrent heart disease, drug toxicity profiles, procedural risks, and patient preferences. Regardless of strategy, given the limited effectiveness of currently available rhythm control therapies, oral anticoagulation is still recommended for stroke prophylaxis in AF patients with other stroke risk factors. Major challenges in atrial fibrillation management include selecting patients most likely to benefit from rhythm control, choosing specific antiarrhythmic drugs or procedures to achieve rhythm control, long-term monitoring to gauge the efficacy of rhythm control, and determining which (if any) patients may safely discontinue anticoagulation if long-term NSR is achieved.

Development of Mu Rhythm in Infants and Preschool Children

PubMed Central

Berchicci, M.; Zhang, T.; Romero, L.; Peters, A.; Annett, R.; Teuscher, U.; Bertollo, M.; Okada, Y.; Stephen, J.; Comani, S.

2011-01-01

Mu rhythm is an idling rhythm that originates in the sensorimotor cortex during rest. The frequency of mu rhythm, which is well established in adults, is 8–12 Hz, whereas the limited results available from children suggest a frequency as low as 5.4 Hz at 6 months of age, which gradually increases to the adult value. Understanding the normal development of mu rhythm has important theoretical and clinical implications since we still know very little about this signal in infants and how it develops with age. We measured mu rhythm over the left hemisphere using a pediatric magnetoencephalography (MEG) system in 25 infants (11–47 weeks), 18 preschool children (2–5 years) and 6 adults (20–39 years) for two 5-min sessions during two intermixed conditions: a rest condition in which the hands were at rest, and a prehension condition in which the subject squeezed a pipette with his/her right hand. In all participants, mu rhythm was present over the frontoparietal area during the rest condition, but was clearly suppressed during the prehension condition. Mu rhythm peak frequency, determined from the amplitude spectra, increased rapidly as a function of age from 2.75 Hz at 11 weeks to 8.25 Hz at 47 weeks (r2 = 0.83). It increased very slowly during the preschool period (3.1 ± 0.9 years; 8.5 ± 0.54 Hz). The frequency in these children was, however, lower than in adults (10.3 ± 1.2 Hz). Our results show a rapid maturation in spontaneous mu rhythm during the first year of life. PMID:21778699

Musical rhythm and reading development: does beat processing matter?

PubMed

Ozernov-Palchik, Ola; Patel, Aniruddh D

2018-05-20

There is mounting evidence for links between musical rhythm processing and reading-related cognitive skills, such as phonological awareness. This may be because music and speech are rhythmic: both involve processing complex sound sequences with systematic patterns of timing, accent, and grouping. Yet, there is a salient difference between musical and speech rhythm: musical rhythm is often beat-based (based on an underlying grid of equal time intervals), while speech rhythm is not. Thus, the role of beat-based processing in the reading-rhythm relationship is not clear. Is there is a distinct relation between beat-based processing mechanisms and reading-related language skills, or is the rhythm-reading link entirely due to shared mechanisms for processing nonbeat-based aspects of temporal structure? We discuss recent evidence for a distinct link between beat-based processing and early reading abilities in young children, and suggest experimental designs that would allow one to further methodically investigate this relationship. We propose that beat-based processing taps into a listener's ability to use rich contextual regularities to form predictions, a skill important for reading development. © 2018 New York Academy of Sciences.

Metabolic circadian rhythms in embryonic turtles.

PubMed

Loudon, Fiona Kay; Spencer, Ricky-John; Strassmeyer, Alana; Harland, Karen

2013-07-01

Oviparous species are model organisms for investigating embryonic development of endogenous physiological circadian rhythms without the influence of maternal biorhythms. Recent studies have demonstrated that heart rates and metabolic rates of embryonic turtles are not constant or always maximal and can be altered in response to the presence of embryos at a more advanced stage of development within the nest. A first step in understanding the physiological mechanisms underpinning these responses in embryonic ectothermic organisms is to develop metabolic profiles (e.g., heart rate) at different temperatures throughout incubation. Heart beat and rhythmic patterns or changes in development may represent important signals or cues within a nest and may be vital to coordinate synchronous hatching well in advance of the final stages of incubation. We developed baseline embryonic heart-rate profiles of embryos of the short-necked Murray River turtle (Emydura macquarii) to determine the stage of embryogenesis that metabolic circadian rhythms become established, if at all. Eggs were incubated at constant temperatures (26°C and 30°C) and heart rates were monitored at 6-h intervals over 24 h every 7-11 days until hatching. Circadian heart rate rhythms were detected at the mid-gestation period and were maintained until hatching. Heart rates throughout the day varied by up to 20% over 24 h and were not related to time of day. This study demonstrated that endogenous metabolic circadian rhythms in developing embryos in turtle eggs establish earlier in embryogenesis than those documented in other vertebrate taxa during embryogenesis. Early establishment of circadian rhythms in heart rates may be critical for communication among embryos and synchrony in hatching and emergence from the nest.

[Rhythm disorders and cardiac crypto-malformations].

PubMed

Davy, J M; Raczka, F; Cung, T T; Combes, N; Bortone, A; Gaty, D

2005-12-01

Faced with a cardiac arrhythmia occuring in an apparently healthy heart, it is necessary to perform an anatomical investigation to detect any unsuspected anomalies. Congenital cardiopathy must certainly be excluded, as this is often responsible for rhythm disorders and/or cardiac conduction defects. Similarly, any acquired conditions, cardiomyopathy, or cardiac tumour must be sought. However, the possibility should always be considered of a minimal congenital malformation, which could be repsonsible for: any type of cardiac arrhythmia: rhythm disorder or conduction defect at the atrial, junctional or ventricular level, with a benign or serious prognosis. Unexpected therapeutic difficulties during radiofrequency ablation procedures or at implantation of pacemakers or defibrillators. Together with rhythm studies, the investigation of choice is high quality imaging, either the classic left or right angiography or the more modern cardiac CT or intracardiac mapping.

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

PubMed

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.

Comparison of English Language Rhythm and Kalhori Kurdish Language Rhythm

ERIC Educational Resources Information Center

Taghva, Nafiseh; Zadeh, Vahideh Abolhasani

2016-01-01

Interval-based method is a method of studying the rhythmic quantitative features of languages. This method use Pairwise Variability Index (PVI) to consider the variability of vocalic duration and inter-vocalic duration of sentences which leads to classification of languages rhythm into stress-timed languages and syllable-timed ones. This study…

Analysis of Handwriting based on Rhythm Perception

NASA Astrophysics Data System (ADS)

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.

Does Melody Assist in the Reproduction of Novel Rhythm Patterns?

ERIC Educational Resources Information Center

Kinney, Daryl W.; Forsythe, Jere L.

2013-01-01

We examined music education majors' ability to reproduce rhythmic stimuli presented in melody and rhythm only conditions. Participants reproduced rhythms of two-measure music examples by immediately echo-performing through a method of their choosing (e.g., clapping, tapping, vocalizing). Forty examples were presented in melody and rhythm only…

Physical constraints on biological integral control design for homeostasis and sensory adaptation.

PubMed

Ang, Jordan; McMillen, David R

2013-01-22

Synthetic biology includes an effort to use design-based approaches to create novel controllers, biological systems aimed at regulating the output of other biological processes. The design of such controllers can be guided by results from control theory, including the strategy of integral feedback control, which is central to regulation, sensory adaptation, and long-term robustness. Realization of integral control in a synthetic network is an attractive prospect, but the nature of biochemical networks can make the implementation of even basic control structures challenging. Here we present a study of the general challenges and important constraints that will arise in efforts to engineer biological integral feedback controllers or to analyze existing natural systems. Constraints arise from the need to identify target output values that the combined process-plus-controller system can reach, and to ensure that the controller implements a good approximation of integral feedback control. These constraints depend on mild assumptions about the shape of input-output relationships in the biological components, and thus will apply to a variety of biochemical systems. We summarize our results as a set of variable constraints intended to provide guidance for the design or analysis of a working biological integral feedback controller. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Emergence, institutionalization and renewal: Rhythms of adaptive governance in complex social-ecological systems.

PubMed

Chaffin, Brian C; Gunderson, Lance H

2016-01-01

Adaptive governance provides the capacity for environmental managers and decision makers to confront variable degrees of uncertainty inherent to complex social-ecological systems. Current theoretical conceptualizations of adaptive governance represent a series of structures and processes best suited for either adapting or transforming existing environmental governance regimes towards forms flexible enough to confront rapid ecological change. As the number of empirical examples of adaptive governance described in the literature grows, the conceptual basis of adaptive governance remains largely under theorized. We argue that reconnecting adaptive governance with foundational concepts of ecological resilience-specifically Panarchy and the adaptive cycle of complex systems-highlights the importance of episodic disturbances and cross-scale interactions in triggering reorganizations in governance. By envisioning the processes of adaptive governance through the lens of Panarchy, scholars and practitioners alike will be better able to identify the emergence of adaptive governance, as well as take advantage of opportunities to institutionalize this type of governance in pursuit of sustainability outcomes. The synergistic analysis of adaptive governance and Panarchy can provide critical insight for analyzing the role of social dynamics during oscillating periods of stability and instability in social-ecological systems. A deeper understanding of the potential for cross-scale interactions to shape adaptive governance regimes may be useful as society faces the challenge of mitigating the impacts of global environmental change. Copyright © 2015 Elsevier Ltd. All rights reserved.

Daily regulation of body temperature rhythm in the camel (Camelus dromedarius) exposed to experimental desert conditions

PubMed Central

Bouâouda, Hanan; Achâaban, Mohamed R.; Ouassat, Mohammed; Oukassou, Mohammed; Piro, Mohamed; Challet, Etienne; El Allali, Khalid; Pévet, Paul

2014-01-01

Abstract In the present work, we have studied daily rhythmicity of body temperature (Tb) in Arabian camels challenged with daily heat, combined or not with dehydration. We confirm that Arabian camels use heterothermy to reduce heat gain coupled with evaporative heat loss during the day. Here, we also demonstrate that this mechanism is more complex than previously reported, because it is characterized by a daily alternation (probably of circadian origin) of two periods of poikilothermy and homeothermy. We also show that dehydration induced a decrease in food intake plays a role in this process. Together, these findings highlight that adaptive heterothermy in the Arabian camel varies across the diurnal light–dark cycle and is modulated by timing of daily heat and degrees of water restriction and associated reduction of food intake. The changed phase relationship between the light–dark cycle and the Tb rhythm observed during the dehydration process points to a possible mechanism of internal desynchronization during the process of adaptation to desert environment. During these experimental conditions mimicking the desert environment, it will be possible in the future to determine if induced high‐amplitude ambient temperature (Ta) rhythms are able to compete with the zeitgeber effect of the light–dark cycle. PMID:25263204

Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

PubMed

Miyazaki, Koyomi; Itoh, Nanako; Ohyama, Sumika; Kadota, Koji; Oishi, Katsutaka

2013-01-01

Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

Preliminary characterization of persisting circadian rhythms during space flight

NASA Technical Reports Server (NTRS)

Sultzman, F. M.

1984-01-01

In order to evaluate the function of the circadian timing system in space, the circadian rhythm of conidiation of the fungus Neurospora crassa was monitored in constant darkness on the STS 9 flight of the Space Shuttle Columbia. During the first 7 days of spaceflight many tubes showed a marked reduction in the apparent amplitude of the conidiation rhythm, and some cultures appeared arrhythmic. There was more variability in the growth rate and circadian rhythms of individual cultures in space than is usually seen on earth. The results of this experiment indicate that while the circadian rhythm of Neurospora conidiation can persist outside of the earth's environment, either the timekeeping process or its expression is altered in space.

The phonetic rhythm/syntax headedness connection: Evidence from Tagalog

NASA Astrophysics Data System (ADS)

Bird, Sonya; Fais, Laurel; Werker, Janet

2005-04-01

Ramus, Nespor, and Mehler [Cognition (1999)] show that the rhythm of a language (broadly: stress- versus syllable- versus mora-timing) results from the proportion of vocalic material in an utterance (%V) and the standard deviation of consonantal intervals (delta-C). Based on 14 languages, Shukla, Nespor, and Mehler [submitted] further argue that rhythm is correlated with syntactic headedness: low %V is correlated with head-first languages (e.g., English); high %V is correlated with head-final languages (e.g., Japanese). Together, these proposals have important implications for language acquisition: infants can discriminate across rhythm classes [Nazzi, Bertoncini, and Mehler, J. Exp. Psych: Human Perception and Performance (1998)]. If rhythm, as defined by %V and delta-C, can predict headedness, then infants can potentially use rhythm information to bootstrap into their languages syntactic structure. This paper reports on a study analyzing rhythm in a language not yet considered: Tagalog. Results support the Shukla et al. proposal in an interesting way: based on its %V and delta-C, Tagalog falls between head-first and head-last languages, slighty closer to the head-first group. This placement correlates well with the fact that, although Tagalog is said to be primarily head-first syntactically, head-last phrases are permitted and common in the language.

Rhythm perception, production, and synchronization during the perinatal period

PubMed Central

Provasi, Joëlle; Anderson, David I.; Barbu-Roth, Marianne

2014-01-01

Sensori-motor synchronization (SMS) is the coordination of rhythmic movement with an external rhythm. It plays a central role in motor, cognitive, and social behavior. SMS is commonly studied in adults and in children from four years of age onward. Prior to this age, the ability has rarely been investigated due to a lack of available methods. The present paper reviews what is known about SMS in young children, infants, newborns, and fetuses. The review highlights fetal and infant perception of rhythm and cross modal perception of rhythm, fetal, and infant production of rhythm and cross modal production of rhythm, and the contexts in which production of rhythm can be observed in infants. A primary question is whether infants, even newborns, can modify their spontaneous rhythmical motor behavior in response to external rhythmical stimulation. Spontaneous sucking, crying, and leg movements have been studied in the presence or absence of rhythmical auditory stimulation. Findings suggest that the interaction between movement and sound is present at birth and that SMS can be observed in special conditions and within a narrow range of tempi, particularly near the infant’s own spontaneous motor tempo. The discussion centers on the fundamental role of SMS in interaction and communication at the beginning of life. PMID:25278929

Salinity fluctuation influencing biological adaptation: growth dynamics and Na+ /K+ -ATPase activity in a euryhaline bacterium.

PubMed

Yang, Hao; Meng, Yang; Song, Youxin; Tan, Yalin; Warren, Alan; Li, Jiqiu; Lin, Xiaofeng

2017-07-01

Although salinity fluctuation is a prominent characteristic of many coastal ecosystems, its effects on biological adaptation have not yet been fully recognized. To test the salinity fluctuations on biological adaptation, population growth dynamics and Na + /K + -ATPase activity were investigated in the euryhaline bacterium Idiomarina sp. DYB, which was acclimated at different salinity exposure levels, exposure times, and shifts in direction of salinity. Results showed: (1) bacterial population growth dynamics and Na + /K + -ATPase activity changed significantly in response to salinity fluctuation; (2) patterns of variation in bacterial growth dynamics were related to exposure times, levels of salinity, and shifts in direction of salinity change; (3) significant tradeoffs were detected between growth rate (r) and carrying capacity (K) on the one hand, and Na + /K + -ATPase activity on the other; and (4) beneficial acclimation was confirmed in Idiomarina sp. DYB. In brief, this study demonstrated that salinity fluctuation can change the population growth dynamics, Na + /K + -ATPase activity, and tradeoffs between r, K, and Na + /K + -ATPase activity, thus facilitating bacterial adaption in a changing environment. These findings provide constructive information for determining biological response patterns to environmental change. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Adaptation responses of individuals to environmental changes in the ciliate Euplotes crassus

NASA Astrophysics Data System (ADS)

Kim, Se-Joo; Kim, Jin-Hyoung; Ju, Se-Jong

2017-03-01

Although the response unit of living organisms to environmental changes is at the individual level, most experiments on the adaptation responses of ciliates have been conducted in batches, comprising multiple-individuals, due to their microscopic size. However, here, we confirmed that individuals undergo different division cycles in monocultures of Euplotes crassus. They also exhibited transcript variations of 4.63-fold in SSU and of 22.78- fold in Hsp70. Additionally, in salt-stressed E. crassus individuals, SSU transcripts of individuals varied by 6.92-fold at 27 psu, 8.69- fold at 32 psu, and 2.51-fold at 37 psu. However, the maximum difference in Hsp70 was only 4.23-fold under all conditions. These results suggest there may be different biological rhythms even in siblings derived from the same parent. It can also be inferred that various environmental factors have different effects on different E. crassus individuals. Therefore, to elucidate relationships between organism adaptations and environmental changes, studies at the individual level should be conducted with multi-individual approaches.

Circadian rhythms in human performance and mood under constant conditions

NASA Technical Reports Server (NTRS)

Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Berga, S. L.; Jarrett, D. B.; Begley, A. E.; Kupfer, D. J.

1997-01-01

This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of 'unmasking' conditions (constant wakeful bedrest, temporal isolation, homogenized 'meals') during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25-30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). In conclusion: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that

Circadian Rhythms and Clock Genes in Reproduction: Insights From Behavior and the Female Rabbit’s Brain

PubMed Central

Caba, Mario; González-Mariscal, Gabriela; Meza, Enrique

2018-01-01

Clock gene oscillations are necessary for a successful pregnancy and parturition, but little is known about their function during lactation, a period demanding from the mother multiple physiological and behavioral adaptations to fulfill the requirements of the offspring. First, we will focus on circadian rhythms and clock genes in reproductive tissues mainly in rodents. Disruption of circadian rhythms or proper rhythmic oscillations of clock genes provoke reproductive problems, as found in clock gene knockout mice. Then, we will focus mainly on the rabbit doe as this mammal nurses the young just once a day with circadian periodicity. This daily event synchronizes the behavior and the activity of specific brain regions critical for reproductive neuroendocrinology and maternal behavior, like the preoptic area. This region shows strong rhythms of the PER1 protein (product of the Per1 clock gene) associated with circadian nursing. Additionally, neuroendocrine cells related to milk production and ejections are also synchronized to daily nursing. A threshold of suckling is necessary to entrain once a day nursing; this process is independent of milk output as even virgin does (behaving maternally following anosmia) can display circadian nursing behavior. A timing motivational mechanism may regulate such behavior as mesolimbic dopaminergic cells are entrained by daily nursing. Finally, we will explore about the clinical importance of circadian rhythms. Indeed, women in chronic shift-work schedules show problems in their menstrual cycles and pregnancies and also have a high risk of preterm delivery, making this an important field of translational research. PMID:29599751

The Automated System of the Rhythm Analysis of the Educational Process in a Higher Educational Institution on the Basis of Aprioristic Data

ERIC Educational Resources Information Center

Pelin, Nicolae; Mironov, Vladimir

2008-01-01

In this article the problems of functioning algorithms development for system of the automated analysis of educational process rhythm in a higher educational institution are considered. Using the device of experiment planning for conducting the scientific researches, adapted methodologies, received by authors in the dissertational works at the…

Differential Sensitivity to Ethanol-Induced Circadian Rhythm Disruption in Adolescent and Adult Mice

PubMed Central

Ruby, Christina L.; Palmer, Kaitlyn N.; Zhang, Jiawen; Risinger, Megan O.; Butkowski, Melissa A.; Swartzwelder, H. Scott

2016-01-01

Background Growing evidence supports a central role for the circadian system in alcohol use disorders, but few studies have examined this relationship during adolescence. In mammals, circadian rhythms are regulated by the suprachiasmatic nucleus (SCN), a biological clock whose timing is synchronized (reset) to the environment primarily by light (photic) input. Alcohol (ethanol) disrupts circadian timing in part by attenuating photic phase-resetting responses in adult rodents. However, circadian rhythms change throughout life and it is not yet known whether ethanol has similar effects on circadian regulation during adolescence. Methods General circadian locomotor activity was monitored in male C57BL6/J mice beginning in adolescence (P27) or adulthood (P61) in a 12 h light, 12 h dark photocycle for ~2 weeks to establish baseline circadian activity measures. On the day of the experiment, mice received an acute injection of ethanol (1.5 g/kg, i.p.) or equal volume saline 15 min prior to a 30-min light pulse at Zeitgeber Time 14 (2 h into the dark phase), then were released into constant darkness (DD) for ~2 weeks to assess phase-resetting responses. Control mice of each age group received injections but no light pulse prior to DD. Results While adults showed the expected decrease in photic phase-delays induced by acute ethanol, this effect was absent in adolescent mice. Adolescents also showed baseline differences in circadian rhythmicity compared to adults, including advanced photocycle entrainment, larger photic phase-delays, a shorter free-running (endogenous) circadian period, and greater circadian rhythm amplitude. Conclusions Collectively, our results indicate that adolescent mice are less sensitive to the effect of ethanol on circadian photic phase-resetting and that their daily activity rhythms are markedly different than those of adults. PMID:27997028

Repeated psychosocial stress at night affects the circadian activity rhythm of male mice.

PubMed

Bartlang, Manuela S; Oster, Henrik; Helfrich-Förster, Charlotte

2015-06-01

We have recently shown that molecular rhythms in the murine suprachiasmatic nucleus (SCN) are affected by repeated social defeat (SD) during the dark/active phase (social defeat dark [SDD]), while repeated SD during the light/inactive phase (social defeat light [SDL]) had no influence on PERIOD2::LUCIFERASE explant rhythms in the SCN. Here we assessed the effects of the same stress paradigm by in vivo biotelemetry on 2 output rhythms of the circadian clock (i.e., activity and core body temperature) in wild-type (WT) and clock-deficient Period (Per)1/2 double-mutant mice during and following repeated SDL and SDD. In general, stress had more pronounced effects on activity compared to body temperature rhythms. Throughout the SD procedure, activity and body temperature were markedly increased during the 2 h of stressor exposure at zeitgeber time (ZT) 1 to ZT3 (SDL mice) and ZT13 to ZT15 (SDD mice), which was compensated by decreased activity during the remaining dark phase (SDL and SDD mice) and light phase (SDL mice) in both genotypes. Considerable differences in the activity between SDL and SDD mice were seen in the poststress period. SDD mice exhibited a reduced first activity bout at ZT13, delayed activity onset, and, consequently, a more narrow activity bandwidth compared with single-housed control (SHC) and SDL mice. Given that this effect was absent in Per1/2 mutant SDD mice and persisted under constant darkness conditions in SDD WT mice, it suggests an involvement of the endogenous clock. Taken together, the present findings demonstrate that SDD has long-lasting consequences for the functional output of the biological clock that, at least in part, appear to depend on the clock genes Per1 and Per2. © 2015 The Author(s).

Circadian temperature rhythms of older people

NASA Technical Reports Server (NTRS)

Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Kupfer, D. J.; Houck, P. R.

1995-01-01

This collection of studies had the aim of exploring whether older (77+ years) men and women have circadian body temperature rhythms different from those of younger adults. A total of 20 older men and 28 older women were compared with either 22 young men or 14 middle-aged men in four protocols; all but the first protocol using a subset of the sample. The four protocols were: 1) 24 h, and 2) 72 h data collections on a normal laboratory routine (sleeping at night); 3) between 36 h and 153 h of field data collection at home; and 4) 36 h of a constant conditions routine (wakeful bedrest under temporal isolation) in the laboratory. There was some evidence for an age-related phase advance in temperature rhythm, especially for the older men on a normal routine, though this was not present in the constant conditions protocol, where 5 of the older subjects showed major delays in the timing of the body temperature trough (10:00 or later). There was no statistically significant evidence from any of the protocols that older subjects generally had lower temperature rhythm amplitudes than younger adults. Only when older men were compared with younger men in 24-h rhythm amplitude by simple t-test did any comparison involving amplitude achieve statistical significance (p < 0.05).

Genomic signatures of adaptation to wine biological ageing conditions in biofilm-forming flor yeasts.

PubMed

Coi, A L; Bigey, F; Mallet, S; Marsit, S; Zara, G; Gladieux, P; Galeote, V; Budroni, M; Dequin, S; Legras, J L

2017-04-01

The molecular and evolutionary processes underlying fungal domestication remain largely unknown despite the importance of fungi to bioindustry and for comparative adaptation genomics in eukaryotes. Wine fermentation and biological ageing are performed by strains of S. cerevisiae with, respectively, pelagic fermentative growth on glucose and biofilm aerobic growth utilizing ethanol. Here, we use environmental samples of wine and flor yeasts to investigate the genomic basis of yeast adaptation to contrasted anthropogenic environments. Phylogenetic inference and population structure analysis based on single nucleotide polymorphisms revealed a group of flor yeasts separated from wine yeasts. A combination of methods revealed several highly differentiated regions between wine and flor yeasts, and analyses using codon-substitution models for detecting molecular adaptation identified sites under positive selection in the high-affinity transporter gene ZRT1. The cross-population composite likelihood ratio revealed selective sweeps at three regions, including in the hexose transporter gene HXT7, the yapsin gene YPS6 and the membrane protein coding gene MTS27. Our analyses also revealed that the biological ageing environment has led to the accumulation of numerous mutations in proteins from several networks, including Flo11 regulation and divalent metal transport. Together, our findings suggest that the tuning of FLO11 expression and zinc transport networks are a distinctive feature of the genetic changes underlying the domestication of flor yeasts. Our study highlights the multiplicity of genomic changes underlying yeast adaptation to man-made habitats and reveals that flor/wine yeast lineage can serve as a useful model for studying the genomics of adaptive divergence. © 2017 John Wiley & Sons Ltd.

Biological adaptations for functional features of language in the face of cultural evolution.

PubMed

Christiansen, Morten H; Reali, Florencia; Chater, Nick

2011-04-01

Although there may be no true language universals, it is nonetheless possible to discern several family resemblance patterns across the languages of the world. Recent work on the cultural evolution of language indicates the source of these patterns is unlikely to be an innate universal grammar evolved through biological adaptations for arbitrary linguistic features. Instead, it has been suggested that the patterns of resemblance emerge because language has been shaped by the brain, with individual languages representing different but partially overlapping solutions to the same set of nonlinguistic constraints. Here, we use computational simulations to investigate whether biological adaptation for functional features of language, deriving from cognitive and communicative constraints, may nonetheless be possible alongside rapid cultural evolution. Specifically, we focus on the Baldwin effect as an evolutionary mechanism by which previously learned linguistic features might become innate through natural selection across many generations of language users. The results indicate that cultural evolution of language does not necessarily prevent functional features of language from becoming genetically fixed, thus potentially providing a particularly informative source of constraints on cross-linguistic resemblance patterns.

Circadian Sleep-Wake Rhythm of Older Adults with Intellectual Disabilities

ERIC Educational Resources Information Center

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…

Neural mechanisms of rhythm-based temporal prediction: Delta phase-locking reflects temporal predictability but not rhythmic entrainment.

PubMed

Breska, Assaf; Deouell, Leon Y

2017-02-01

Predicting the timing of upcoming events enables efficient resource allocation and action preparation. Rhythmic streams, such as music, speech, and biological motion, constitute a pervasive source for temporal predictions. Widely accepted entrainment theories postulate that rhythm-based predictions are mediated by synchronizing low-frequency neural oscillations to the rhythm, as indicated by increased phase concentration (PC) of low-frequency neural activity for rhythmic compared to random streams. However, we show here that PC enhancement in scalp recordings is not specific to rhythms but is observed to the same extent in less periodic streams if they enable memory-based prediction. This is inconsistent with the predictions of a computational entrainment model of stronger PC for rhythmic streams. Anticipatory change in alpha activity and facilitation of electroencephalogram (EEG) manifestations of response selection are also comparable between rhythm- and memory-based predictions. However, rhythmic sequences uniquely result in obligatory depression of preparation-related premotor brain activity when an on-beat event is omitted, even when it is strategically beneficial to maintain preparation, leading to larger behavioral costs for violation of prediction. Thus, while our findings undermine the validity of PC as a sign of rhythmic entrainment, they constitute the first electrophysiological dissociation, to our knowledge, between mechanisms of rhythmic predictions and of memory-based predictions: the former obligatorily lead to resonance-like preparation patterns (that are in line with entrainment), while the latter allow flexible resource allocation in time regardless of periodicity in the input. Taken together, they delineate the neural mechanisms of three distinct modes of preparation: continuous vigilance, interval-timing-based prediction and rhythm-based prediction.

Neural mechanisms of rhythm-based temporal prediction: Delta phase-locking reflects temporal predictability but not rhythmic entrainment

PubMed Central

Deouell, Leon Y.

2017-01-01

Predicting the timing of upcoming events enables efficient resource allocation and action preparation. Rhythmic streams, such as music, speech, and biological motion, constitute a pervasive source for temporal predictions. Widely accepted entrainment theories postulate that rhythm-based predictions are mediated by synchronizing low-frequency neural oscillations to the rhythm, as indicated by increased phase concentration (PC) of low-frequency neural activity for rhythmic compared to random streams. However, we show here that PC enhancement in scalp recordings is not specific to rhythms but is observed to the same extent in less periodic streams if they enable memory-based prediction. This is inconsistent with the predictions of a computational entrainment model of stronger PC for rhythmic streams. Anticipatory change in alpha activity and facilitation of electroencephalogram (EEG) manifestations of response selection are also comparable between rhythm- and memory-based predictions. However, rhythmic sequences uniquely result in obligatory depression of preparation-related premotor brain activity when an on-beat event is omitted, even when it is strategically beneficial to maintain preparation, leading to larger behavioral costs for violation of prediction. Thus, while our findings undermine the validity of PC as a sign of rhythmic entrainment, they constitute the first electrophysiological dissociation, to our knowledge, between mechanisms of rhythmic predictions and of memory-based predictions: the former obligatorily lead to resonance-like preparation patterns (that are in line with entrainment), while the latter allow flexible resource allocation in time regardless of periodicity in the input. Taken together, they delineate the neural mechanisms of three distinct modes of preparation: continuous vigilance, interval-timing-based prediction and rhythm-based prediction. PMID:28187128

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

PubMed

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.

Circadian rhythms of gastrointestinal function are regulated by both central and peripheral oscillators

PubMed Central

Malloy, Jaclyn N.; Paulose, Jiffin K.; Li, Ye

2012-01-01

Circadian clocks are responsible for daily rhythms in a wide array of processes, including gastrointestinal (GI) function. These are vital for normal digestive rhythms and overall health. Previous studies demonstrated circadian clocks within the cells of GI tissue. The present study examines the roles played by the suprachiasmatic nuclei (SCN), master circadian pacemaker for overt circadian rhythms, and the sympathetic nervous system in regulation of circadian GI rhythms in the mouse Mus musculus. Surgical ablation of the SCN abolishes circadian locomotor, feeding, and stool output rhythms when animals are presented with food ad libitum, while restricted feeding reestablishes these rhythms temporarily. In intact mice, chemical sympathectomy with 6-hydroxydopamine has no effect on feeding and locomotor rhythmicity in light-dark cycles or constant darkness but attenuates stool weight and stool number rhythms. Again, however, restricted feeding reestablishes rhythms in locomotor activity, feeding, and stool output rhythms. Ex vivo, intestinal tissue from PER2::LUC transgenic mice expresses circadian rhythms of luciferase bioluminescence. Chemical sympathectomy has little effect on these rhythms, but timed administration of the β-adrenergic agonist isoproterenol causes a phase-dependent shift in PERIOD2 expression rhythms. Collectively, the data suggest that the SCN are required to maintain feeding, locomotor, and stool output rhythms during ad libitum conditions, acting at least in part through daily activation of sympathetic activity. Even so, this input is not necessary for entrainment to timed feeding, which may be the province of oscillators within the intestines themselves or other components of the GI system. PMID:22723262

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

PubMed

Margraf, Jürgen; Lavallee, Kristen; Zhang, XiaoChi; Schneider, Silvia

2016-01-01

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.

Neural Responses to Complex Auditory Rhythms: The Role of Attending

PubMed Central

Chapin, Heather L.; Zanto, Theodore; Jantzen, Kelly J.; Kelso, Scott J. A.; Steinberg, Fred; Large, Edward W.

2010-01-01

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 cortex, insula, anterior cingulate, and prefrontal cortex, and suppressed activity in sensory areas associated with attending to the visual stimulus. PMID:21833279

Adaptation of sensor morphology: an integrative view of perception from biologically inspired robotics perspective

PubMed Central

Nurzaman, Surya G.

2016-01-01

Sensor morphology, the morphology of a sensing mechanism which plays a role of shaping the desired response from physical stimuli from surroundings to generate signals usable as sensory information, is one of the key common aspects of sensing processes. This paper presents a structured review of researches on bioinspired sensor morphology implemented in robotic systems, and discusses the fundamental design principles. Based on literature review, we propose two key arguments: first, owing to its synthetic nature, biologically inspired robotics approach is a unique and powerful methodology to understand the role of sensor morphology and how it can evolve and adapt to its task and environment. Second, a consideration of an integrative view of perception by looking into multidisciplinary and overarching mechanisms of sensor morphology adaptation across biology and engineering enables us to extract relevant design principles that are important to extend our understanding of the unfinished concepts in sensing and perception. PMID:27499843

Chronobiology --2017 Nobel Prize in Physiology or Medicine.

PubMed

Yuan, Li; Li, Yi-Rou; Xu, Xiao-Dong

2018-01-20

Chronobiology is a field of biology that examines the generation of biological rhythms in various creatures and in many parts of body, and their adaptive fitness to solar- and lunar-related periodic phenomena. The synchronization of internal circadian clocks with external timing signals confers accurate phase response and tissue homeostasis. Herein we state a series of studies on circadian rhythms and introduce the brief history of chronobiology. We also present a detailed timeline of the discoveries on molecular mechanisms controlling circadian rhythm in Drosophila, which was awarded the 2017 Nobel Prize in Physiology or Medicine. The latest findings and new perspectives are further summarized to indicate the significance of circadian research.

Implications of Circadian Rhythm in Dopamine and Mood Regulation.

PubMed

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.

Dopamine-dependent non-linear correlation between subthalamic rhythms in Parkinson's disease.

PubMed

Marceglia, S; Foffani, G; Bianchi, A M; Baselli, G; Tamma, F; Egidi, M; Priori, A

2006-03-15

The basic information architecture in the basal ganglia circuit is under debate. Whereas anatomical studies quantify extensive convergence/divergence patterns in the circuit, suggesting an information sharing scheme, neurophysiological studies report an absence of linear correlation between single neurones in normal animals, suggesting a segregated parallel processing scheme. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys and in parkinsonian patients single neurones become linearly correlated, thus leading to a loss of segregation between neurones. Here we propose a possible integrative solution to this debate, by extending the concept of functional segregation from the cellular level to the network level. To this end, we recorded local field potentials (LFPs) from electrodes implanted for deep brain stimulation (DBS) in the subthalamic nucleus (STN) of parkinsonian patients. By applying bispectral analysis, we found that in the absence of dopamine stimulation STN LFP rhythms became non-linearly correlated, thus leading to a loss of segregation between rhythms. Non-linear correlation was particularly consistent between the low-beta rhythm (13-20 Hz) and the high-beta rhythm (20-35 Hz). Levodopa administration significantly decreased these non-linear correlations, therefore increasing segregation between rhythms. These results suggest that the extensive convergence/divergence in the basal ganglia circuit is physiologically necessary to sustain LFP rhythms distributed in large ensembles of neurones, but is not sufficient to induce correlated firing between neurone pairs. Conversely, loss of dopamine generates pathological linear correlation between neurone pairs, alters the patterns within LFP rhythms, and induces non-linear correlation between LFP rhythms operating at different frequencies. The pathophysiology of information processing in the human basal ganglia therefore involves not only activities of individual rhythms, but also

Dopamine-dependent non-linear correlation between subthalamic rhythms in Parkinson's disease

PubMed Central

Marceglia, S; Foffani, G; Bianchi, A M; Baselli, G; Tamma, F; Egidi, M; Priori, A

2006-01-01

The basic information architecture in the basal ganglia circuit is under debate. Whereas anatomical studies quantify extensive convergence/divergence patterns in the circuit, suggesting an information sharing scheme, neurophysiological studies report an absence of linear correlation between single neurones in normal animals, suggesting a segregated parallel processing scheme. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys and in parkinsonian patients single neurones become linearly correlated, thus leading to a loss of segregation between neurones. Here we propose a possible integrative solution to this debate, by extending the concept of functional segregation from the cellular level to the network level. To this end, we recorded local field potentials (LFPs) from electrodes implanted for deep brain stimulation (DBS) in the subthalamic nucleus (STN) of parkinsonian patients. By applying bispectral analysis, we found that in the absence of dopamine stimulation STN LFP rhythms became non-linearly correlated, thus leading to a loss of segregation between rhythms. Non-linear correlation was particularly consistent between the low-beta rhythm (13–20 Hz) and the high-beta rhythm (20–35 Hz). Levodopa administration significantly decreased these non-linear correlations, therefore increasing segregation between rhythms. These results suggest that the extensive convergence/divergence in the basal ganglia circuit is physiologically necessary to sustain LFP rhythms distributed in large ensembles of neurones, but is not sufficient to induce correlated firing between neurone pairs. Conversely, loss of dopamine generates pathological linear correlation between neurone pairs, alters the patterns within LFP rhythms, and induces non-linear correlation between LFP rhythms operating at different frequencies. The pathophysiology of information processing in the human basal ganglia therefore involves not only activities of individual rhythms, but also

Circadian Activity Rhythms, Time Urgency, and Achievement Concerns.

ERIC Educational Resources Information Center

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…

Analysis of Rhythms in Experimental Signals

NASA Astrophysics Data System (ADS)

Desherevskii, A. V.; Zhuravlev, V. I.; Nikolsky, A. N.; Sidorin, A. Ya.

2017-12-01

We compare algorithms designed to extract quasiperiodic components of a signal and estimate the amplitude, phase, stability, and other characteristics of a rhythm in a sliding window in the presence of data gaps. Each algorithm relies on its own rhythm model; therefore, it is necessary to use different algorithms depending on the research objectives. The described set of algorithms and methods is implemented in the WinABD software package, which includes a time-series database management system, a powerful research complex, and an interactive data-visualization environment.

Human adipose tissue expresses intrinsic circadian rhythm in insulin sensitivity.

PubMed

Carrasco-Benso, Maria P; Rivero-Gutierrez, Belen; Lopez-Minguez, Jesus; Anzola, Andrea; Diez-Noguera, Antoni; Madrid, Juan A; Lujan, Juan A; Martínez-Augustin, Olga; Scheer, Frank A J L; Garaulet, Marta

2016-09-01

In humans, insulin sensitivity varies according to time of day, with decreased values in the evening and at night. Mechanisms responsible for the diurnal variation in insulin sensitivity are unclear. We investigated whether human adipose tissue (AT) expresses intrinsic circadian rhythms in insulin sensitivity that could contribute to this phenomenon. Subcutaneous and visceral AT biopsies were obtained from extremely obese participants (body mass index, 41.8 ± 6.3 kg/m(2); 46 ± 11 y) during gastric-bypass surgery. To assess the rhythm in insulin signaling, AKT phosphorylation was determined every 4 h over 24 h in vitro in response to different insulin concentrations (0, 1, 10, and 100 nM). Data revealed that subcutaneous AT exhibited robust circadian rhythms in insulin signaling (P < 0.00001). Insulin sensitivity reached its maximum (acrophase) around noon, being 54% higher than during midnight (P = 0.009). The amplitude of the rhythm was positively correlated with in vivo sleep duration (r = 0.53; P = 0.023) and negatively correlated with in vivo bedtime (r = -0.54; P = 0.020). No circadian rhythms were detected in visceral AT (P = 0.643). Here, we demonstrate the relevance of the time of the day for how sensitive AT is to the effects of insulin. Subcutaneous AT shows an endogenous circadian rhythm in insulin sensitivity that could provide an underlying mechanism for the daily rhythm in systemic insulin sensitivity.-Carrasco-Benso, M. P., Rivero-Gutierrez, B., Lopez-Minguez, J., Anzola, A., Diez-Noguera, A., Madrid, J. A., Lujan, J. A., Martínez-Augustin, O., Scheer, F. A. J. L., Garaulet, M. Human adipose tissue expresses intrinsic circadian rhythm in insulin sensitivity. © FASEB.

Daily rhythms of body temperature and heat production of sibling Mastomys species from different ecosystems--the response to photoperiod manipulations.

PubMed

Haim, Abraham; Zubidat, Abed Elsalam; van Aarde, Rudi J

2008-12-01

We compared body temperature (T(b)) and metabolic rates, measured as oxygen consumption (VO(2)), daily rhythms of two sibling species of the genus Mastomys. We also studied their responses to long day (16L: 8D, LD) and short day (8L: 16D, SD) photoperiod manipulations at a constant ambient temperature of 26+1 degrees C. We noted significant differences in T(b) and VO(2) daily rhythm patterns, under SD and LD-acclimation between the sibling species. These differences explain adaptation to the climatic conditions that prevail in the different ecosystems where these species live. To the best of our knowledge, this is the first time that physiological differences between the two siblings are measured by using chronobiological methods.

Maneuvering control and configuration adaptation of a biologically inspired morphing aircraft

NASA Astrophysics Data System (ADS)

Abdulrahim, Mujahid

Natural flight as a source of inspiration for aircraft design was prominent with early aircraft but became marginalized as aircraft became larger and faster. With recent interest in small unmanned air vehicles, biological inspiration is a possible technology to enhance mission performance of aircraft that are dimensionally similar to gliding birds. Serial wing joints, loosely modeling the avian skeletal structure, are used in the current study to allow significant reconfiguration of the wing shape. The wings are reconfigured to optimize aerodynamic performance and maneuvering metrics related to specific mission tasks. Wing shapes for each mission are determined and related to the seagulls, falcons, albatrosses, and non-migratory African swallows on which the aircraft are based. Variable wing geometry changes the vehicle dynamics, affording versatility in flight behavior but also requiring appropriate compensation to maintain stability and controllability. Time-varying compensation is in the form of a baseline controller which adapts to both the variable vehicle dynamics and to the changing mission requirements. Wing shape is adapted in flight to minimize a cost function which represents energy, temporal, and spatial efficiency. An optimal control architecture unifies the control and adaptation tasks.

Capturing microscopic features of bone remodeling into a macroscopic model based on biological rationales of bone adaptation.

PubMed

Kim, Young Kwan; Kameo, Yoshitaka; Tanaka, Sakae; Adachi, Taiji

2017-10-01

To understand Wolff's law, bone adaptation by remodeling at the cellular and tissue levels has been discussed extensively through experimental and simulation studies. For the clinical application of a bone remodeling simulation, it is significant to establish a macroscopic model that incorporates clarified microscopic mechanisms. In this study, we proposed novel macroscopic models based on the microscopic mechanism of osteocytic mechanosensing, in which the flow of fluid in the lacuno-canalicular porosity generated by fluid pressure gradients plays an important role, and theoretically evaluated the proposed models, taking biological rationales of bone adaptation into account. The proposed models were categorized into two groups according to whether the remodeling equilibrium state was defined globally or locally, i.e., the global or local uniformity models. Each remodeling stimulus in the proposed models was quantitatively evaluated through image-based finite element analyses of a swine cancellous bone, according to two introduced criteria associated with the trabecular volume and orientation at remodeling equilibrium based on biological rationales. The evaluation suggested that nonuniformity of the mean stress gradient in the local uniformity model, one of the proposed stimuli, has high validity. Furthermore, the adaptive potential of each stimulus was discussed based on spatial distribution of a remodeling stimulus on the trabecular surface. The theoretical consideration of a remodeling stimulus based on biological rationales of bone adaptation would contribute to the establishment of a clinically applicable and reliable simulation model of bone remodeling.

Circadian Rhythm Sleep-Wake Disorders in Older Adults.

PubMed

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.

Interplay between environmentally modulated feedback loops - hypoxia and circadian rhythms - two sides of the same coin?

PubMed

Depping, Reinhard; Oster, Henrik

2017-11-01

Sensing of environmental parameters is critically important for cells of metazoan organisms. Members of the superfamily of bHLH-PAS transcription factors, involved in oxygen sensing and circadian rhythm generation, are important players in such molecular pathways. The interplay between both networks includes a so far unknown factor, connecting PER2 (circadian clocks) to hypoxia sensing (HIF-1 α) to result in a more adapted state of homeostasis at the right time. © 2017 Federation of European Biochemical Societies.

Circadian rhythms in Macaca mulatta monkeys during Bion 11 flight

NASA Technical Reports Server (NTRS)

Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.; Tumurova, E. G.; Fuller, C. A.

2000-01-01

Circadian rhythms of primate brain temperature, head and ankle skin temperature, motor activity, and heart rate were studied during spaceflight and on the ground. In space, the circadian rhythms of all the parameters were synchronized with diurnal Zeitgebers. However, in space the brain temperature rhythm showed a significantly more delayed phase angle, which may be ascribed to an increase of the endogenous circadian period.

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

PubMed

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.

Speech-Like Rhythm in a Voiced and Voiceless Orangutan Call

PubMed Central

Lameira, Adriano R.; Hardus, Madeleine E.; Bartlett, Adrian M.; Shumaker, Robert W.; Wich, Serge A.; Menken, Steph B. J.

2015-01-01

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 antecedents

Body temperature variability (Part 1): a review of the history of body temperature and its variability due to site selection, biological rhythms, fitness, and aging.

PubMed

Kelly, Greg

2006-12-01

Body temperature is a complex, non-linear data point, subject to many sources of internal and external variation. While these sources of variation significantly complicate interpretation of temperature data, disregarding knowledge in favor of oversimplifying complex issues would represent a significant departure from practicing evidence-based medicine. Part 1 of this review outlines the historical work of Wunderlich on temperature and the origins of the concept that a healthy normal temperature is 98.6 degrees F (37.0 degrees C). Wunderlich's findings and methodology are reviewed and his results are contrasted with findings from modern clinical thermometry. Endogenous sources of temperature variability, including variations caused by site of measurement, circadian, menstrual, and annual biological rhythms, fitness, and aging are discussed. Part 2 will review the effects of exogenous masking agents - external factors in the environment, diet, or lifestyle that can influence body temperature, as well as temperature findings in disease states.

Obesity: a disease or a biological adaptation? An update.

PubMed

Chaput, J-P; Doucet, E; Tremblay, A

2012-08-01

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a 'collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population. © 2012 The Authors. obesity reviews © 2012 International Association for the Study of Obesity.

Therapeutic applications of circadian rhythms for the cardiovascular system

PubMed Central

Tsimakouridze, Elena V.; Alibhai, Faisal J.; Martino, Tami A.

2015-01-01

The cardiovascular system exhibits dramatic time-of-day dependent rhythms, for example the diurnal variation of heart rate, blood pressure, and timing of onset of adverse cardiovascular events such as heart attack and sudden cardiac death. Over the past decade, the circadian clock mechanism has emerged as a crucial factor regulating these daily fluctuations. Most recently, these studies have led to a growing clinical appreciation that targeting circadian biology offers a novel therapeutic approach toward cardiovascular (and other) diseases. Here we describe leading-edge therapeutic applications of circadian biology including (1) timing of therapy to maximize efficacy in treating heart disease (chronotherapy); (2) novel biomarkers discovered by testing for genomic, proteomic, metabolomic, or other factors at different times of day and night (chronobiomarkers); and (3) novel pharmacologic compounds that target the circadian mechanism with potential clinical applications (new chronobiology drugs). Cardiovascular disease remains a leading cause of death worldwide and new approaches in the management and treatment of heart disease are clearly warranted and can benefit patients clinically. PMID:25941487

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

PubMed

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

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

PubMed Central

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

2015-01-01

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 72 h 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 R2, 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 (eta2) 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

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

PubMed

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.

Are circadian rhythms new pathways to understand Autism Spectrum Disorder?

PubMed

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.

Renal electrolyte circadian rhythms - Independence from feeding and activity patterns

NASA Technical Reports Server (NTRS)

Moore-Ede, M. C.; Herd, J. A.

1977-01-01

Experiments were conducted on six unanesthetized chair-acclimatized adult male squirrel monkeys (Saimiri sciureus) weighing 600-900 g to determine whether internal synchronization is the result of simple passive dependence of renal excretory rhythms on endogenous rhythms of those variable that influence electrolyte excretion such as dietary intake and muscular activity. Independence of the urinary rhythms from diurnal variations in feeding, drinking, and activity was secured by depriving the animals of food, water, and training them to perform a two-hourly schedule of feeding, drinking, and activity throughout day and night. Results indicate that the internal synchronization which is normally observed between the behavioral and urinary rhythms cannot be explained by any direct dependence of renal function on behavioral patterns. The most probable mechanism for circadian internal synchronization is that the various behavioral and renal rhythms are controlled by potentially independent separate oscillators which are normally kept in synchrony with one another.

Characterization of neurospora circadian rhythms in space

NASA Technical Reports Server (NTRS)

Ferraro, James S.

1987-01-01

To determine whether the circadian rhythm of conidiation in neurospora crassa is endogenously derived or is driven by some geophysical time cue, an experiment was conducted on space shuttle flight STS-9, where inoculated race tubes were exposed to the microgravity environment of space. The results demonstated that the rhythm can persist in space. However, there were several minor alterations noted; an increase in the period of the oscillation and the variability of the growth rate and a diminished rhythm amplitude, which eventually damped out in 25% of the flight tubes. On day seven of the flight, the tubes were exposed to light while their growth fronts were marked. It appears that some aspects of this marking process reinstated a robust rhythm in all the tubes which continued throughout the remainder of the flight. It was hypothesized that the damping found prior to the marking procedure on STS-9 may have been a result of the hypergravity pulse of launch and not due to the microgravity of the orbital lab; furthermore, that the marking procedure, by exposing the samples to light, had reinstated rhythmicity. To test this, an investigation was conducted into the effects of acute and chronic exposure to hypergravity.

Measuring Child Rhythm

ERIC Educational Resources Information Center

Payne, Elinor; Post, Brechtje; Astruc, Lluisa; Prieto, Pilar; Vanrell, Maria del Mar

2012-01-01

Interval-based rhythm metrics were applied to the speech of English, Catalan and Spanish 2, 4 and 6 year-olds, and compared with the (adult-directed) speech of their mothers. Results reveal that child speech does not fall into a well-defined rhythmic class: for all three languages, it is more "vocalic" (higher %V) than adult speech and…

Pilot Investigation of the Circadian Plasma Melatonin Rhythm across the Menstrual Cycle in a Small Group of Women with Premenstrual Dysphoric Disorder

PubMed Central

Shechter, Ari; Lespérance, Paul; Ng Ying Kin, N. M. K.; Boivin, Diane B.

2012-01-01

Women with premenstrual dysphoric disorder (PMDD) experience mood deterioration and altered circadian rhythms during the luteal phase (LP) of their menstrual cycles. Disturbed circadian rhythms may be involved in the development of clinical mood states, though this relationship is not fully characterized in PMDD. We therefore conducted an extensive chronobiological characterization of the melatonin rhythm in a small group of PMDD women and female controls. In this pilot study, participants included five women with PMDD and five age-matched controls with no evidence of menstrual-related mood disorders. Participants underwent two 24-hour laboratory visits, during the follicular phase (FP) and LP of the menstrual cycle, consisting of intensive physiological monitoring under “unmasked”, time-isolation conditions. Measures included visual analogue scale for mood, ovarian hormones, and 24-hour plasma melatonin. Mood significantly (P≤.03) worsened during LP in PMDD compared to FP and controls. Progesterone was significantly (P = .025) increased during LP compared to FP, with no between-group differences. Compared to controls, PMDD women had significantly (P<.05) decreased melatonin at circadian phases spanning the biological night during both menstrual phases and reduced amplitude of its circadian rhythm during LP. PMDD women also had reduced area under the curve of melatonin during LP compared to FP. PMDD women showed affected circadian melatonin rhythms, with reduced nocturnal secretion and amplitude during the symptomatic phase compared to controls. Despite our small sample size, these pilot findings support a role for disturbed circadian rhythms in affective disorders. Possible associations with disrupted serotonergic transmission are proposed. PMID:23284821

Space Resources for Teachers: Biology, Including Suggestions for Classroom Activities and Laboratory Experiments.

ERIC Educational Resources Information Center

Lee, Tom E.; And Others

This compilation of resource units concerns the latest developments in space biology. Some of the topics included are oxygen consumption, temperature, radiation, rhythms, weightlessness, acceleration and vibration stress, toxicity, and sensory and perceptual problems. Many of the topics are interdisciplinary and relate biology, physiology,…

Speech rhythm in Kannada speaking adults who stutter.

PubMed

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.

The development of new purification methods to assess the circadian rhythm of body temperature in Mongolian gerbils.

PubMed

Weinert, D; Nevill, A; Weinandy, R; Waterhouse, J

2003-03-01

Six Mongolian gerbils were studied for 8-10d while housed in separate cages in a 12:12h light-dark (L-D) cycle (lights on at 07:00h). Recordings of body temperature, heart rate, and spontaneous activity were made throughout. The temperature and heart rate rhythms were "purified" to take into account the effects of activity, and then the rhythm of temperature was further purified to take into account other masking influences ("non-activity masking effects" or NAME,). The methods employed in the purification processes involved linear regression analysis or analysis of covariance, the latter using functions of activity and NAME as covariates. From these methods, it was possible to obtain not only an estimate of the endogenous component of the temperature rhythm but also a measure of circadian changes in the sensitivity of temperature to masking effects. Even though all purification methods removed many of the effects of spontaneous activity from the temperature record, there remained temperature fluctuations at the L-D and D-L transitions that appeared to be independent of activity. The NAME was of only very marginal value in the purification process. Comparison of the purification methods indicated that the linear methods were inferior (both from a biological viewpoint and when the results were compared mathematically) to those that allowed the rate of rise of temperature due to increasing amounts of activity to become progressively less. The sensitivity of temperature and heart rate to the masking effects of activity showed a circadian rhythm, with sensitivities in the resting phase being greater than those in the active phase. These findings are compatible with the view that thermoregulatory reflexes are induced by spontaneous activity of sufficient amount, and that there is a circadian rhythm in the body temperature at which these reflexes are initiated and in their effectiveness.

Spotlight on fish: light pollution affects circadian rhythms of European perch but does not cause stress.

PubMed

Brüning, Anika; Hölker, Franz; Franke, Steffen; Preuer, Torsten; Kloas, Werner

2015-04-01

Flora and fauna evolved under natural day and night cycles. However, natural light is now enhanced by artificial light at night, particularly in urban areas. This alteration of natural light environments during the night is hypothesised to alter biological rhythms in fish, by effecting night-time production of the hormone melatonin. Artificial light at night is also expected to increase the stress level of fish, resulting in higher cortisol production. In laboratory experiments, European perch (Perca fluviatilis) were exposed to four different light intensities during the night, 0 lx (control), 1 lx (potential light level in urban waters), 10 lx (typical street lighting at night) and 100 lx. Melatonin and cortisol concentrations were measured from water samples every 3h during a 24 hour period. This study revealed that the nocturnal increase in melatonin production was inhibited even at the lowest light level of 1 lx. However, cortisol levels did not differ between control and treatment illumination levels. We conclude that artificial light at night at very low intensities may disturb biological rhythms in fish since nocturnal light levels around 1 lx are already found in urban waters. However, enhanced stress induction could not be demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

Biological stress response terminology: Integrating the concepts of adaptive response and preconditioning stress within a hormetic dose-response framework.

PubMed

Calabrese, Edward J; Bachmann, Kenneth A; Bailer, A John; Bolger, P Michael; Borak, Jonathan; Cai, Lu; Cedergreen, Nina; Cherian, M George; Chiueh, Chuang C; Clarkson, Thomas W; Cook, Ralph R; Diamond, David M; Doolittle, David J; Dorato, Michael A; Duke, Stephen O; Feinendegen, Ludwig; Gardner, Donald E; Hart, Ronald W; Hastings, Kenneth L; Hayes, A Wallace; Hoffmann, George R; Ives, John A; Jaworowski, Zbigniew; Johnson, Thomas E; Jonas, Wayne B; Kaminski, Norbert E; Keller, John G; Klaunig, James E; Knudsen, Thomas B; Kozumbo, Walter J; Lettieri, Teresa; Liu, Shu-Zheng; Maisseu, Andre; Maynard, Kenneth I; Masoro, Edward J; McClellan, Roger O; Mehendale, Harihara M; Mothersill, Carmel; Newlin, David B; Nigg, Herbert N; Oehme, Frederick W; Phalen, Robert F; Philbert, Martin A; Rattan, Suresh I S; Riviere, Jim E; Rodricks, Joseph; Sapolsky, Robert M; Scott, Bobby R; Seymour, Colin; Sinclair, David A; Smith-Sonneborn, Joan; Snow, Elizabeth T; Spear, Linda; Stevenson, Donald E; Thomas, Yolene; Tubiana, Maurice; Williams, Gary M; Mattson, Mark P

2007-07-01

Many biological subdisciplines that regularly assess dose-response relationships have identified an evolutionarily conserved process in which a low dose of a stressful stimulus activates an adaptive response that increases the resistance of the cell or organism to a moderate to severe level of stress. Due to a lack of frequent interaction among scientists in these many areas, there has emerged a broad range of terms that describe such dose-response relationships. This situation has become problematic because the different terms describe a family of similar biological responses (e.g., adaptive response, preconditioning, hormesis), adversely affecting interdisciplinary communication, and possibly even obscuring generalizable features and central biological concepts. With support from scientists in a broad range of disciplines, this article offers a set of recommendations we believe can achieve greater conceptual harmony in dose-response terminology, as well as better understanding and communication across the broad spectrum of biological disciplines.

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

PubMed

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1983-06-01

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 rolemore » 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.« less

Addressing the controversy of rate-versus-rhythm control in atrial fibrillation.

PubMed

Contractor, Tahmeed; Levin, Vadim; Desai, Ravi; Marchlinski, Francis E

2013-09-01

Atrial fibrillation is the most common sustained cardiac arrhythmia and significantly increases patient risk of stroke, cardiomyopathy, and mortality. Rate versus rhythm control as the "best" treatment strategy remains an issue of considerable, ongoing debate. A multitude of clinical trials have compared the 2 strategies and have not shown any benefit of one approach over the other. However, the trials were conducted in specific subgroups of patients and demonstrated low success rates with antiarrhythmic drug (AAD) therapy and a high incidence of adverse AAD effects. Sub-analyses of the trials have confirmed that successful rhythm control with sinus rhythm restoration is associated with a significant reduction in patient mortality. More recently, radiofrequency ablation (RFA) has emerged as a relatively effective procedure for maintaining sinus rhythm compared with use of AADs. Prospective randomized studies have shown good treatment results after the use of RFA, with acceptable risk. Given the limitation of pharmacologic rate versus rhythm control studies, and the promise of RFA, rhythm control should again be reconsidered as the "best" approach for managing many subgroups of patients with atrial fibrillation.

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

PubMed

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.

Hierarchy of models: From qualitative to quantitative analysis of circadian rhythms in cyanobacteria

NASA Astrophysics Data System (ADS)

Chaves, M.; Preto, M.

2013-06-01

A hierarchy of models, ranging from high to lower levels of abstraction, is proposed to construct "minimal" but predictive and explanatory models of biological systems. Three hierarchical levels will be considered: Boolean networks, piecewise affine differential (PWA) equations, and a class of continuous, ordinary, differential equations' models derived from the PWA model. This hierarchy provides different levels of approximation of the biological system and, crucially, allows the use of theoretical tools to more exactly analyze and understand the mechanisms of the system. The Kai ABC oscillator, which is at the core of the cyanobacterial circadian rhythm, is analyzed as a case study, showing how several fundamental properties—order of oscillations, synchronization when mixing oscillating samples, structural robustness, and entrainment by external cues—can be obtained from basic mechanisms.

A Circadian Rhythm Regulating Hyphal Melanization in Cercospora Kikuchii

USDA-ARS?s Scientific Manuscript database

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...

Visual Enhancement of Illusory Phenomenal Accents in Non-Isochronous Auditory Rhythms

PubMed Central

2016-01-01

Musical rhythms encompass temporal patterns that often yield regular metrical accents (e.g., a beat). There have been mixed results regarding perception as a function of metrical saliency, namely, whether sensitivity to a deviant was greater in metrically stronger or weaker positions. Besides, effects of metrical position have not been examined in non-isochronous rhythms, or with respect to multisensory influences. This study was concerned with two main issues: (1) In non-isochronous auditory rhythms with clear metrical accents, how would sensitivity to a deviant be modulated by metrical positions? (2) Would the effects be enhanced by multisensory information? Participants listened to strongly metrical rhythms with or without watching a point-light figure dance to the rhythm in the same meter, and detected a slight loudness increment. Both conditions were presented with or without an auditory interference that served to impair auditory metrical perception. Sensitivity to a deviant was found greater in weak beat than in strong beat positions, consistent with the Predictive Coding hypothesis and the idea of metrically induced illusory phenomenal accents. The visual rhythm of dance hindered auditory detection, but more so when the latter was itself less impaired. This pattern suggested that the visual and auditory rhythms were perceptually integrated to reinforce metrical accentuation, yielding more illusory phenomenal accents and thus lower sensitivity to deviants, in a manner consistent with the principle of inverse effectiveness. Results were discussed in the predictive framework for multisensory rhythms involving observed movements and possible mediation of the motor system. PMID:27880850

Floral thermogenesis: An adaptive strategy of pollination biology in Magnoliaceae

PubMed Central

Wang, Ruohan; Zhang, Zhixiang

2015-01-01

Floral thermogenesis plays a crucial role in pollination biology, especially in plant–pollinator interactions. We have recently explored how thermogenesis is related to pollinator activity and odour release in Magnolia sprengeri. By analyzing flower temperatures, emission of volatiles, and insect visitation, we found that floral blends released during pistillate and staminate stages were similar and coincided with sap beetle visitation. Thus, odour mimicry of staminate-stage flowers may occur during the pistillate stage and may be an adaptive strategy of Magnolia species to attract pollinators during both stages, ensuring successful pollination. In addition to the biological significance of floral thermogenesis in Magnolia species, we explored the underlying regulatory mechanisms via profiling miRNA expression in M. denudata flowers during thermogenic and non-thermogenic stages. We identified 17 miRNAs that may play regulatory roles in floral thermogenesis. Functional annotation of their target genes indicated that these miRNAs regulate floral thermogenesis by influencing cellular respiration and light reactions. These findings increase our understanding of plant–pollinator interactions and the regulatory mechanisms in thermogenic plants. PMID:26844867

The circatidal rhythm persists without the optic lobe in the mangrove cricket Apteronemobius asahinai.

PubMed

Takekata, Hiroki; Numata, Hideharu; Shiga, Sakiko

2014-02-01

Whether the circatidal rhythm is generated by a machinery common to the circadian clock is one of the important and interesting questions in chronobiology. The mangrove cricket Apteronemobius asahinai shows a circatidal rhythm generating active and inactive phases and a circadian rhythm modifying the circatidal rhythm by inhibiting activity during the subjective day simultaneously. In the previous study, RNA interference of the circadian clock gene period disrupted the circadian rhythm but not the circatidal rhythm, suggesting a difference in molecular mechanisms between the circatidal and circadian rhythms. In the present study, to compare the neural mechanisms of these 2 rhythms, we observed locomotor activity in the mangrove cricket after surgical removal of the optic lobe, which has been shown to be the locus of the circadian clock in other crickets. We also noted the pigment-dispersing factor immunoreactive neurons (PDF-IRNs) in the optic lobe, because PDF is a key output molecule in the circadian clock system in some insects. The results showed that the circadian modulation was disrupted after the removal of the optic lobes but that the circatidal rhythm was maintained with no remarkable changes in its free-running period. Even in crickets in which some PDF-immunoreactive somata remained after removal of the optic lobe, the circadian rhythm was completely disrupted. The remnants of PDF-IRNs were not correlated to the occurrence and free-running period of the circatidal rhythm. These results indicate that the principal circatidal clock is located in a region(s) different from the optic lobe, whereas the circadian clock is located in the optic lobe, as in other crickets, and PDF-IRNs are not important for circatidal rhythm. Therefore, it is suggested that the circatidal rhythm of A. asahinai is driven by a neural basis different from that driving the circadian rhythm.

Machine-Learning Based Co-adaptive Calibration: A Perspective to Fight BCI Illiteracy

NASA Astrophysics Data System (ADS)

Vidaurre, Carmen; Sannelli, Claudia; Müller, Klaus-Robert; Blankertz, Benjamin

"BCI illiteracy" is one of the biggest problems and challenges in BCI research. It means that BCI control cannot be achieved by a non-negligible number of subjects (estimated 20% to 25%). There are two main causes for BCI illiteracy in BCI users: either no SMR idle rhythm is observed over motor areas, or this idle rhythm is not attenuated during motor imagery, resulting in a classification performance lower than 70% (criterion level) already for offline calibration data. In a previous work of the same authors, the concept of machine learning based co-adaptive calibration was introduced. This new type of calibration provided substantially improved performance for a variety of users. Here, we use a similar approach and investigate to what extent co-adapting learning enables substantial BCI control for completely novice users and those who suffered from BCI illiteracy before.

Sleep, Circadian Rhythms, and Performance During Space Shuttle Missions

NASA Technical Reports Server (NTRS)

Neri, David F.; Czeisler, Charles A.; Dijk, Derk-Jan; Wyatt, James K.; Ronda, Joseph M.; Hughes, Rod J.

2003-01-01

Sleep and circadian rhythms may be disturbed during spaceflight, and these disturbances can affect crewmembers' performance during waking hours. The mechanisms underlying sleep and circadian rhythm disturbances in space are not well understood, and effective countermeasures are not yet available. We investigated sleep, circadian rhythms, cognitive performance, and light-dark cycles in five astronauts prior to, during, and after the 16-day STS-90 mission and the IO-day STS-95 mission. The efficacy of low-dose, alternative-night, oral melatonin administration as a countermeasure for sleep disturbances was evaluated. During these missions, scheduled rest activity cycles were 20-35 minutes shorter than 24 hours. Light levels on the middeck and in the Spacelab were very low; whereas on the flight deck (which has several windows), they were highly variable. Circadian rhythm abnormalities were observed. During the second half of the missions, the rhythm of urinary cortisol appeared to be delayed relative to the sleep-wake schedule. Performance during wakefulness was impaired. Astronauts slept only about 6.5 hours per day, and subjective sleep quality was lower in space. No beneficial effects of melatonin (0.3 mg administered prior to sleep episodes on alternate nights) were observed. A surprising finding was a marked increase in rapid eye movement (REM) sleep upon return to Earth. We conclude that these Space Shuttle missions were associated with circadian rhythm disturbances, sleep loss, decrements in neurobehavioral performance, and alterations in REM sleep homeostasis. Shorter than 24-hour rest-activity schedules and exposure to light-dark cycles inadequate for optimal circadian synchronization may have contributed to these disturbances.

Ultradian rhythm unmasked in the Pdf clock mutant of Drosophila.

PubMed

Seki, Yuuichi; Tanimura, Teiichi

2014-09-01

A diverse range of organisms shows physiological and behavioural rhythms with various periods. Extensive studies have been performed to elucidate the molecular mechanisms of circadian rhythms with an approximately 24 h period in both Drosophila and mammals, while less attention has been paid to ultradian rhythms with shorter periods. We used a video-tracking method to monitor the movement of single flies, and clear ultradian rhythms were detected in the locomotor behaviour of wild type and clock mutant flies kept under constant dark conditions. In particular, the Pigment-dispersing factor mutant (Pdf 01) demonstrated a precise and robust ultradian rhythmicity, which was not temperature compensated. Our results suggest that Drosophila has an endogenous ultradian oscillator that is masked by circadian rhythmic behaviours.

A stochastic model of input effectiveness during irregular gamma rhythms.

PubMed

Dumont, Grégory; Northoff, Georg; Longtin, André

2016-02-01

Gamma-band synchronization has been linked to attention and communication between brain regions, yet the underlying dynamical mechanisms are still unclear. How does the timing and amplitude of inputs to cells that generate an endogenously noisy gamma rhythm affect the network activity and rhythm? How does such "communication through coherence" (CTC) survive in the face of rhythm and input variability? We present a stochastic modelling approach to this question that yields a very fast computation of the effectiveness of inputs to cells involved in gamma rhythms. Our work is partly motivated by recent optogenetic experiments (Cardin et al. Nature, 459(7247), 663-667 2009) that tested the gamma phase-dependence of network responses by first stabilizing the rhythm with periodic light pulses to the interneurons (I). Our computationally efficient model E-I network of stochastic two-state neurons exhibits finite-size fluctuations. Using the Hilbert transform and Kuramoto index, we study how the stochastic phase of its gamma rhythm is entrained by external pulses. We then compute how this rhythmic inhibition controls the effectiveness of external input onto pyramidal (E) cells, and how variability shapes the window of firing opportunity. For transferring the time variations of an external input to the E cells, we find a tradeoff between the phase selectivity and depth of rate modulation. We also show that the CTC is sensitive to the jitter in the arrival times of spikes to the E cells, and to the degree of I-cell entrainment. We further find that CTC can occur even if the underlying deterministic system does not oscillate; quasicycle-type rhythms induced by the finite-size noise retain the basic CTC properties. Finally a resonance analysis confirms the relative importance of the I cell pacing for rhythm generation. Analysis of whole network behaviour, including computations of synchrony, phase and shifts in excitatory-inhibitory balance, can be further sped up by orders of

I got rhythm: Gershwin and birth control in the 1930s.

PubMed

Viterbo, Paula

2004-03-01

Gershwin's song 'I Got Rhythm' serves here as a backdrop representing the social context of the inter-war years. On center stage is a particular aspect of the history of birth control--the application of a new theory of ovulation to contraception. Starting in 1928, a series of experiments revealed a biochemical rhythm in the female reproductive cycle, which contradicted the widespread idea that ovulation and pregnancy could occur at any time. This discovery was applied to a new contraceptive method, the rhythm method, which enjoyed significant popularity during the 1930s, especially among Catholics. For a short period, women could join Ethel Merman in the refrain 'I got rhythm, I got my man, who could ask for anything more?' But the rhythm method has not lived to its promise, and the play goes on em leader

Psycho-physiological mechanisms of adaptation of rotation personnel in Arctic regions.

PubMed

Krivoschekov, S G; Shishkina, T N

1998-01-01

Transit workers (240 oil industry workers, aged 19-50) living in the European part of Russia and flying to work in the northern regions of West Siberia (Tyumen district) were observed. Psychological status was determined by the method of Taylor. Biological rhythms, chemical control of ventilation, oxygen (O2) and carbon dioxide (CO2) consumption, body temperature, and hormone-metabolic data were assessed. The analysis of illness for the Nadymgazprom Enterprise was carried out in accordance with the medical charts. One may notice a certain cyclic recurrence of the adaptation process. Thus, the first stage of vigorous rearrangement of the psycho-physiological regulation system is followed by a period of relative stability, the result of initiation of compensatory processes. Compensation mechanisms, however, may become disabled, triggering development of a disadaptive state. Results of these scientific investigations were used to introduce new transit work regimens at Nadymgazprom Enterprise.

Biological clocks: their relevance to immune-allergic diseases.

PubMed

Paganelli, Roberto; Petrarca, Claudia; Di Gioacchino, Mario

2018-01-01

The 2017 Nobel Prize for Physiology or Medicine, awarded for the discoveries made in the past 15 years on the genetic and molecular mechanisms regulating many physiological functions, has renewed the attention to the importance of circadian rhythms. These originate from a central pacemaker in the suprachiasmatic nucleus in the brain, photoentrained via direct connection with melanopsin containing, intrinsically light-sensitive retinal ganglion cells, and it projects to periphery, thus creating an inner circadian rhythm. This regulates several activities, including sleep, feeding times, energy metabolism, endocrine and immune functions. Disturbances of these rhythms, mainly of wake/sleep, hormonal secretion and feeding, cause decrease in quality of life, as well as being involved in development of obesity, metabolic syndrome and neuropsychiatric disorders. Most immunological functions, from leukocyte numbers, activity and cytokine secretion undergo circadian variations, which might affect susceptibility to infections. The intensity of symptoms and disease severity show a 24 h pattern in many immunological and allergic diseases, including rheumatoid arthritis, bronchial asthma, atopic eczema and chronic urticaria. This is accompanied by altered sleep duration and quality, a major determinant of quality of life. Shift work and travel through time zones as well as artificial light pose new health threats by disrupting the circadian rhythms. Finally, the field of chronopharmacology uses these concepts for delivering drugs in synchrony with biological rhythms.

Circadian rhythms of visual accommodation responses and physiological correlations.

NASA Technical Reports Server (NTRS)

Murphy, M. R.; Randle, R. J.; Williams, B. A.

1972-01-01

Use of a recently developed servocontrolled infrared optometer to continuously record the state of monocular focus while subjects viewed a visual target for which the stimulus to focus was systematically varied. Calculated parameters form recorded data - e.g., speeds of accommodation to approaching and receding targets, magnitude of accommodation to step changes in target distance, and amplitude and phase lag of response to sinusoidally varying stimuli were submitted to periodicity analyses. Ear canal temperature (ECT) and heart rate (HR) rhythms were also recorded for physiological correlation with accommodation rhythms. HR demonstrated a 24-hr rhythm, but ECT data did not.

Correlations between Circadian Rhythms and Growth in Challenging Environments.

PubMed

Dakhiya, Yuri; Hussien, Duaa; Fridman, Eyal; Kiflawi, Moshe; Green, Rachel

2017-03-01

In plants, the circadian system controls a plethora of processes, many with agronomic importance, such as photosynthesis, photoprotection, stomatal opening, and photoperiodic development, as well as molecular processes, such as gene expression. It has been suggested that modifying circadian rhythms may be a means to manipulate crops to develop improved plants for agriculture. However, there is very little information on how the clock influences the performance of crop plants. We used a noninvasive, high-throughput technique, based on prompt chlorophyll fluorescence, to measure circadian rhythms and demonstrated that the technique works in a range of plants. Using fluorescence, we analyzed circadian rhythms in populations of wild barley ( Hordeum vulgare ssp. spontaneum ) from widely different ecogeographical locations in the Southern Levant part of the Fertile Crescent, an area with a high proportion of the total genetic variation of wild barley. Our results show that there is variability for circadian traits in the wild barley lines. We observed that circadian period lengths were correlated with temperature and aspect at the sites of origin of the plants, while the amplitudes of the rhythms were correlated with soil composition. Thus, different environmental parameters may exert selection on circadian rhythms. © 2017 American Society of Plant Biologists. All Rights Reserved.

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

PubMed Central

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

Cortisol-mediated synchronization of circadian rhythm in urinary potassium excretion

NASA Technical Reports Server (NTRS)

Moore-Ede, M. C.; Schmelzer, W. S.; Kass, D. A.; Herd, J. A.

1977-01-01

Conscious chair-acclimatized squirrel monkeys (Saimiri sciureus) studied with lights on (600 lx) from 0800 to 2000 hr daily (LD 12:12) display a prominent circadian rhythm in renal potassium excretion. The characteristics of this rhythm were reproduced in adrenalectomized monkeys by infusing 5 mg cortisol and 0.001 mg aldosterone, or 5 mg cortisol alone, between 0800 and 0900 kr daily. When the timing of cortisol administration (with or without aldosterone) was phase-delayed by 8 hr, the urinary potassium rhythm resynchronized by 80% of the cortisol phase shift, but only after a transient response lasting 3-4 days. With the same daily dose of adrenal steroids given as a continuous infusion throughout each 24 hr, urinary potassium excretion showed free-running oscillations no longer synchronized to the light-dark cycle. These results indicate that the circadian rhythm of plasma cortisol concentration acts as an internal mediator in the circadian timing system, synchronizing a potentially autonomous oscillation in renal potassium excretion to environmental time cues and to other circadian rhythms within the animal.

Studying circadian rhythm and sleep using genetic screens in Drosophila.

PubMed

Axelrod, Sofia; Saez, Lino; Young, Michael W

2015-01-01

The power of Drosophila melanogaster as a model organism lies in its ability to be used for large-scale genetic screens with the capacity to uncover the genetic basis of biological processes. In particular, genetic screens for circadian behavior, which have been performed since 1971, allowed researchers to make groundbreaking discoveries on multiple levels: they discovered that there is a genetic basis for circadian behavior, they identified the so-called core clock genes that govern this process, and they started to paint a detailed picture of the molecular functions of these clock genes and their encoded proteins. Since the discovery that fruit flies sleep in 2000, researchers have successfully been using genetic screening to elucidate the many questions surrounding this basic animal behavior. In this chapter, we briefly recall the history of circadian rhythm and sleep screens and then move on to describe techniques currently employed for mutagenesis and genetic screening in the field. The emphasis lies on comparing the newer approaches of transgenic RNA interference (RNAi) to classical forms of mutagenesis, in particular in their application to circadian behavior and sleep. We discuss the different screening approaches in light of the literature and published and unpublished sleep and rhythm screens utilizing ethyl methanesulfonate mutagenesis and transgenic RNAi from our lab. © 2015 Elsevier Inc. All rights reserved.

Circadian rhythms as a basis for work organization: a study with live line electricians.

PubMed

Guimarães, Lia Buarque de Macedo; Ribeiro, Jose Luis Duarte; Saurin, Tarcísio Abreu; de Bittencourt Júnior, Paulo Ivo Homem

2013-02-01

With the assumption that circadian rhythms influence human performance, the work of live line electricians was reorganized and evaluated. The hypothesis was that in highly physical and attention-demanding work, the organization of tasks, according to the ideal period of day and day of week, should diminish stress and consequent work risks. There are only a few studies reporting the work of electricians and even fewer approaching work organization. Moreover, these investigations often do not consider human physiological limitations and capabilities as well as task demands. A new work system was proposed with consideration of (a) the circadian cycles and homeostatic processes; (b) the effect of heat, which is a zeitgeber (synchronizer) for the biological clocks; and (c) the degree of physical and mental demands of the different performed tasks, which was assessed on the basis of opinions of the electricians and physiological markers of stress that are controlled by circadian rhythms. The traditional and new systems were compared on the basis of two cognitive indices (the arrangement of matchsticks and the perception of a minute) and three physiological markers of mental-to-physical loads (heart frequency and the level of adrenaline and noradrenaline). Both physical and mental loads were reduced in the new system. Work organization should include consideration of human circadian rhythms, mainly when stressful and high-risk tasks are involved. The findings can be applied in any work design, but they are especially suited for highly demanding work carried out outdoors.

Diurnal cortisol rhythms, fatigue and psychosocial factors in five-year survivors of ovarian cancer.

PubMed

Cuneo, Michaela G; Schrepf, Andrew; Slavich, George M; Thaker, Premal H; Goodheart, Michael; Bender, David; Cole, Steve W; Sood, Anil K; Lutgendorf, Susan K

2017-10-01

Fatigue is a challenge in ovarian cancer survivorship and greatly impacts quality of life. In other cancer populations, fatigue has been associated with abnormal diurnal cortisol patterns. However, little is known about biological and behavioral factors in 5+-year ovarian cancer survivors and potential mechanisms underlying persistent fatigue have not been investigated in this population. Moreover, relationships between neuroendocrine and psychosocial factors in 5+-year ovarian cancer survivors have not been studied. We addressed these issues by examining relationships between diurnal cortisol rhythms, fatigue, life stress, and social support in 30 survivors of ovarian cancer who were assessed at least 5 years (mean=6.20years) following their primary diagnosis. Flatter diurnal cortisol slopes were associated with higher levels of fatigue, suggesting a role for HPA-axis dysregulation in sustained fatigue experienced by survivors. Moreover, greater cumulative lifetime stressor exposure (p=0.023) and stressor severity (p=0.004) were associated with flatter diurnal cortisol slopes, while higher social attachment (p=0.001) was associated with steeper diurnal cortisol slopes. These findings suggest that ovarian cancer survivors with greater lifetime stress exposure or lower social attachment may be at increased risk for circadian rhythm disruption, which in turn is associated with fatigue. Future research should examine relationships of clinical stage and inflammatory cytokines to cortisol rhythms and fatigue in long-term ovarian cancer survivors, as well as investigating the clinical significance of abnormal diurnal cortisol profiles in this population. Copyright © 2017 Elsevier Ltd. All rights reserved.

Case study of psychophysiological diary: infradian rhythms.

PubMed

Slover, G P; Morris, R W; Stroebel, C F; Patel, M K

1987-01-01

A 4-year case study was made of a 42-year-old white woman as seen through the psychophysiological diary. There was an awakening diary and a bedtime diary composed of 125 variables. The data are divided into two series: series I containing a manic episode, and series II as a control. Spectral analysis shows infradian rhythms in hypoglycemia and fear (11 days) and time to fall asleep (5 days). Depressed feelings showed a circatrigintan (28-day) rhythm, which was not correlated with menses. Mania had an annual rhythm (spring) but no circatrigintan or less rhythm. The following correlations have a P value less than or equal to 0.01: mania was directly correlated with number of sleeping pills, time to really wake up, need for rest, moodiness, and helplessness, and indirectly with expectations, pressure at work, sense of time, and emotional state. Interestingly, awakening pulse is directly correlated with awakening temperature, number of sleeping pills, bedtime pulse, tiredness at bedtime, hypoglycemia, and fear. Bedtime pulse is directly correlated with awakening pulse and awakening temperature. Both pulse and temperature at bedtime are directly correlated with negative variables such as tiredness, moodiness, helplessness, and depression, and inversely correlated with positive variables such as happiness, loving, performance at work, and thinking efficiency. This study demonstrates a significant correlation between physiological variables.

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers

PubMed Central

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

2016-01-01

Summary The rhythmic opening/closing and volatile emissions of flowers is 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 led to the identification of core circadian clock components in Arabidopsis thaliana, involvement of these clock components for floral rhythms remained untested likely due to 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 as a core clock component. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. PMID:26439540

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

PubMed

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.

Adapting federated cyberinfrastructure for shared data collection facilities in structural biology

PubMed Central

Stokes-Rees, Ian; Levesque, Ian; Murphy, Frank V.; Yang, Wei; Deacon, Ashley; Sliz, Piotr

2012-01-01

Early stage experimental data in structural biology is generally unmaintained and inaccessible to the public. It is increasingly believed that this data, which forms the basis for each macromolecular structure discovered by this field, must be archived and, in due course, published. Furthermore, the widespread use of shared scientific facilities such as synchrotron beamlines complicates the issue of data storage, access and movement, as does the increase of remote users. This work describes a prototype system that adapts existing federated cyberinfra­structure technology and techniques to significantly improve the operational environment for users and administrators of synchrotron data collection facilities used in structural biology. This is achieved through software from the Virtual Data Toolkit and Globus, bringing together federated users and facilities from the Stanford Synchrotron Radiation Lightsource, the Advanced Photon Source, the Open Science Grid, the SBGrid Consortium and Harvard Medical School. The performance and experience with the prototype provide a model for data management at shared scientific facilities. PMID:22514186

Adapting federated cyberinfrastructure for shared data collection facilities in structural biology.

PubMed

Stokes-Rees, Ian; Levesque, Ian; Murphy, Frank V; Yang, Wei; Deacon, Ashley; Sliz, Piotr

2012-05-01

Early stage experimental data in structural biology is generally unmaintained and inaccessible to the public. It is increasingly believed that this data, which forms the basis for each macromolecular structure discovered by this field, must be archived and, in due course, published. Furthermore, the widespread use of shared scientific facilities such as synchrotron beamlines complicates the issue of data storage, access and movement, as does the increase of remote users. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to significantly improve the operational environment for users and administrators of synchrotron data collection facilities used in structural biology. This is achieved through software from the Virtual Data Toolkit and Globus, bringing together federated users and facilities from the Stanford Synchrotron Radiation Lightsource, the Advanced Photon Source, the Open Science Grid, the SBGrid Consortium and Harvard Medical School. The performance and experience with the prototype provide a model for data management at shared scientific facilities.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease.

PubMed

Holleran, Grainne; Lopetuso, Loris; Petito, Valentina; Graziani, Cristina; Ianiro, Gianluca; McNamara, Deirdre; Gasbarrini, Antonio; Scaldaferri, Franco

2017-09-21

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

PubMed Central

Holleran, Grainne; Lopetuso, Loris; Petito, Valentina; Graziani, Cristina; Ianiro, Gianluca; McNamara, Deirdre; Gasbarrini, Antonio; Scaldaferri, Franco

2017-01-01

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date. PMID:28934123

Sense of rhythm does not differentiate professional hurdlers from non-athletes.

PubMed

Skowronek, Tomasz; Słomka, Kajetan; Juras, Grzegorz; Szade, Bartlomiej

2013-08-01

The importance of rhythm and specific endurance capabilities were examined in the technical skill and performance of hurdle runners. Additionally, interaction effects among rhythm, anaerobic fitness, and body constitution were analyzed. Seven 18-year-old members of the Polish Junior National Team in 110 m hurdles and 8 age-matched controls who were non-athletes participated. Movement coordination tests (rhythm and differentiation tests) and an anaerobic fitness test were performed. There were no statistically significant differences between the athletes and the control group on the coordination or rhythm test variables. No support was found for the hypothesis that a hurdler's timing ability influences performance.

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

ERIC Educational Resources Information Center

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…

Synchronization to light and mealtime of daily rhythms of locomotor activity, plasma glucose and digestive enzymes in the Nile tilapia (Oreochromis niloticus).

PubMed

Guerra-Santos, Bartira; López-Olmeda, José Fernando; de Mattos, Bruno Olivetti; Baião, Alice Borba; Pereira, Denise Soledade Peixoto; Sánchez-Vázquez, Francisco Javier; Cerqueira, Robson Bahia; Albinati, Ricardo Castelo Branco; Fortes-Silva, Rodrigo

2017-02-01

The light-dark cycle and feeding can be the most important factors acting as synchronizers of biological rhythms. In this research we aimed to evaluate synchronization to feeding schedule of daily rhythms of locomotor activity and digestive enzymes of tilapia. For that purpose, 120 tilapias (65.0±0.6g) were distributed in 12 tanks (10 fish per tank) and divided into two groups. One group was fed once a day at 11:00h (zeitgeber time, ZT6) (ML group) and the other group was fed at 23:00h (ZT18) (MD group). The fish were anesthetized to collect samples of blood, stomach and midgut at 4-hour intervals over a period of 24h. Fish fed at ML showed a diurnal locomotor activity (74% of the total daily activity occurring during the light phase) and synchronization to the feeding schedule, as this group showed anticipation to the feeding time. Fish fed at MD showed a disruption in the pattern of locomotor activity and became less diurnal (59%). Alkaline protease activity in the midgut showed daily rhythm with the achrophase at the beginning of the dark phase in both ML and MD groups. Acid protease and amylase did not show significant daily rhythms. Plasma glucose showed a daily rhythm with the achrophase shifted by 12h in the ML and MD groups. These results revealed that the feeding time and light cycle synchronize differently the daily rhythms of behavior, digestive physiology and plasma metabolites in the Nile tilapia, which indicate the plasticity of the circadian system and its synchronizers. Copyright © 2016 Elsevier Inc. All rights reserved.

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

PubMed

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.

Gamma Rhythm Simulations in Alzheimer's Disease

NASA Astrophysics Data System (ADS)

Montgomery, Samuel; Perez, Carlos; Ullah, Ghanim

The different neural rhythms that occur during the sleep-wake cycle regulate the brain's multiple functions. Memory acquisition occurs during fast gamma rhythms during consciousness, while slow oscillations mediate memory consolidation and erasure during sleep. At the neural network level, these rhythms are generated by the finely timed activity within excitatory and inhibitory neurons. In Alzheimer's Disease (AD) the function of inhibitory neurons is compromised due to an increase in amyloid beta (A β) leading to elevated sodium leakage from extracellular space in the hippocampus. Using a Hodgkin-Huxley formalism, heightened sodium leakage current into inhibitory neurons is observed to compromise functionality. Using a simple two neuron system it was observed that as the conductance of the sodium leakage current is increased in inhibitory neurons there is a significant decrease in spiking frequency regarding the membrane potential. This triggers a significant increase in excitatory spiking leading to aberrant network behavior similar to that seen in AD patients. The next step is to extend this model to a larger neuronal system with varying synaptic densities and conductance strengths as well as deterministic and stochastic drives.

The Effect of Pitch and Rhythm Difficulty on Vocal Sight-Reading Performance

ERIC Educational Resources Information Center

Henry, Michele L.

2011-01-01

Singing music at sight is a complex skill, requiring the singer to perform pitch and rhythm simultaneously. Previous research has identified difficulty levels for pitch and rhythm skills individually but not in combination. In this study, the author sought to determine the relationship between pitch and rhythm tasks occurring concurrently. High…

Computer-based rhythm diagnosis and its possible influence on nonexpert electrocardiogram readers.

PubMed

Hakacova, Nina; Trägårdh-Johansson, Elin; Wagner, Galen S; Maynard, Charles; Pahlm, Olle

2012-01-01

Systems providing computer-based analysis of the resting electrocardiogram (ECG) seek to improve the quality of health care by providing accurate and timely automatic diagnosis of, for example, cardiac rhythm to clinicians. The accuracy of these diagnoses, however, remains questionable. We tested the hypothesis that (a) 2 independent automated ECG systems have better accuracy in rhythm diagnosis than nonexpert clinicians and (b) both systems provide correct diagnostic suggestions in a large percentage of cases where the diagnosis of nonexpert clinicians is incorrect. Five hundred ECGs were manually analyzed by 2 senior experts, 3 nonexpert clinicians, and automatically by 2 automated systems. The accuracy of the nonexpert rhythm statements was compared with the accuracy of each system statement. The proportion of rhythm statements when the clinician's diagnoses were incorrect and the systems instead provided correct diagnosis was assessed. A total of 420 sinus rhythms and 156 rhythm disturbances were recognized by expert reading. Significance of the difference in accuracy between nonexperts and systems was P = .45 for system A and P = .11 for system B. The percentage of correct automated diagnoses in cases when the clinician was incorrect was 28% ± 10% for system A and 25% ± 11% for system B (P = .09). The rhythm diagnoses of automated systems did not reach better average accuracy than those of nonexpert readings. The computer diagnosis of rhythm can be incorrect in cases where the clinicians fail in reaching the correct ECG diagnosis. Copyright © 2012. Published by Elsevier Inc.

Thalamocortical mechanisms for integrating musical tone and rhythm

PubMed Central

Musacchia, Gabriella; Large, Edward

2014-01-01

Studies over several decades have identified many of the neuronal substrates of music perception by pursuing pitch and rhythm perception separately. Here, we address the question of how these mechanisms interact, starting with the observation that the peripheral pathways of the so-called “Core” and “Matrix” thalamocortical system provide the anatomical bases for tone and rhythm channels. We then examine the hypothesis that these specialized inputs integrate tonal content within rhythm context in auditory cortex using classical types of “driving” and “modulatory” mechanisms. This hypothesis provides a framework for deriving testable predictions about the early stages of music processing. Furthermore, because thalamocortical circuits are shared by speech and music processing, such a model provides concrete implications for how music experience contributes to the development of robust speech encoding mechanisms. PMID:24103509

Variation in the daily rhythm of body temperature of free-living Arabian oryx (Oryx leucoryx): does water limitation drive heterothermy?

PubMed

Hetem, Robyn Sheila; Strauss, Willem Maartin; Fick, Linda Gayle; Maloney, Shane Kevin; Meyer, Leith Carl Rodney; Shobrak, Mohammed; Fuller, Andrea; Mitchell, Duncan

2010-10-01

Heterothermy, a variability in body temperature beyond the limits of homeothermy, has been advanced as a key adaptation of Arabian oryx (Oryx leucoryx) to their arid-zone life. We measured body temperature using implanted data loggers, for a 1-year period, in five oryx free-living in the deserts of Saudi Arabia. As predicted for adaptive heterothermy, during hot months compared to cooler months, not only were maximum daily body temperatures higher (41.1 ± 0.3 vs. 39.7 ± 0.1°C, P = 0.0002) but minimum daily body temperatures also were lower (36.1 ± 0.3 vs. 36.8 ± 0.2°C, P = 0.04), resulting in a larger daily amplitude of the body temperature rhythm (5.0 ± 0.5 vs. 2.9 ± 0.2°C, P = 0.0007), while mean daily body temperature rose by only 0.4°C. The maximum daily amplitude of the body temperature rhythm reached 7.7°C for two of our oryx during the hot-dry period, the largest amplitude ever recorded for a large mammal. Body temperature variability was influenced not only by ambient temperature but also water availability, with oryx displaying larger daily amplitudes of the body temperature rhythm during warm-dry months compared to warm-wet months (3.6 ± 0.6 vs. 2.3 ± 0.3°C, P = 0.005), even though ambient temperatures were the same. Free-living Arabian oryx therefore employ heterothermy greater than that recorded in any other large mammal, but water limitation, rather than high ambient temperature, seems to be the primary driver of this heterothermy.

Crosslinguistic application of English-centric rhythm descriptors in motor speech disorders.

PubMed

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

2013-01-01

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. 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. 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. Copyright © 2013 S. Karger AG, Basel.

Aging human circadian rhythms: conventional wisdom may not always be right

NASA Technical Reports Server (NTRS)

Monk, Timothy H.

2005-01-01

This review discusses the ways in which the circadian rhythms of older people are different from those of younger adults. After a brief discussion of clinical issues, the review describes the conventional wisdom regarding age-related changes in circadian rhythms. These can be summarized as four assertions regarding what happens to people as they get older: 1) the amplitude of their circadian rhythms reduces, 2) the phase of their circadian rhythms becomes earlier, 3) their natural free-running period (tau) shortens, and 4) their ability to tolerate abrupt phase shifts (e.g., from jet travel or night work) worsens. The review then discusses the empirical evidence for and against these assertions and discusses some alternative explanations. The conclusions are that although older people undoubtedly have earlier circadian phases than younger adults, and have more trouble coping with shift work and jet lag, evidence for the assertions about rhythm amplitude and tau are, at best, mixed.

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

PubMed Central

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

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

PubMed

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.

Subjectivity: A Case of Biological Individuation and an Adaptive Response to Informational Overflow

PubMed Central

Jonkisz, Jakub

2016-01-01

The article presents a perspective on the scientific explanation of the subjectivity of conscious experience. It proposes plausible answers for two empirically valid questions: the ‘how’ question concerning the developmental mechanisms of subjectivity, and the ‘why’ question concerning its function. Biological individuation, which is acquired in several different stages, serves as a provisional description of how subjective perspectives may have evolved. To the extent that an individuated informational space seems the most efficient way for a given organism to select biologically valuable information, subjectivity is deemed to constitute an adaptive response to informational overflow. One of the possible consequences of this view is that subjectivity might be (at least functionally) dissociated from consciousness, insofar as the former primarily facilitates selection, the latter action. PMID:27555835

Neural mechanisms of rhythm perception: current findings and future perspectives.

PubMed

Grahn, Jessica A

2012-10-01

Perception of temporal patterns is fundamental to normal hearing, speech, motor control, and music. Certain types of pattern understanding are unique to humans, such as musical rhythm. Although human responses to musical rhythm are universal, there is much we do not understand about how rhythm is processed in the brain. Here, I consider findings from research into basic timing mechanisms and models through to the neuroscience of rhythm and meter. A network of neural areas, including motor regions, is regularly implicated in basic timing as well as processing of musical rhythm. However, fractionating the specific roles of individual areas in this network has remained a challenge. Distinctions in activity patterns appear between "automatic" and "cognitively controlled" timing processes, but the perception of musical rhythm requires features of both automatic and controlled processes. In addition, many experimental manipulations rely on participants directing their attention toward or away from certain stimulus features, and measuring corresponding differences in neural activity. Many temporal features, however, are implicitly processed whether attended to or not, making it difficult to create controlled baseline conditions for experimental comparisons. The variety of stimuli, paradigms, and definitions can further complicate comparisons across domains or methodologies. Despite these challenges, the high level of interest and multitude of methodological approaches from different cognitive domains (including music, language, and motor learning) have yielded new insights and hold promise for future progress. Copyright © 2012 Cognitive Science Society, Inc.

Find a Heart Rhythm Specialist

MedlinePlus

... Taiwan Thailand Turkey United Arab Emirates United Kingdom Venezuela Vietnam Within 5 miles 10 miles 15 miles ... info@HRSonline.org © Heart Rhythm Society 2017 Privacy Policy | Linking Policy | Patient Education Disclaimer You are about ...

A biological inspired fuzzy adaptive window median filter (FAWMF) for enhancing DNA signal processing.

PubMed

Ahmad, Muneer; Jung, Low Tan; Bhuiyan, Al-Amin

2017-10-01

Digital signal processing techniques commonly employ fixed length window filters to process the signal contents. DNA signals differ in characteristics from common digital signals since they carry nucleotides as contents. The nucleotides own genetic code context and fuzzy behaviors due to their special structure and order in DNA strand. Employing conventional fixed length window filters for DNA signal processing produce spectral leakage and hence results in signal noise. A biological context aware adaptive window filter is required to process the DNA signals. This paper introduces a biological inspired fuzzy adaptive window median filter (FAWMF) which computes the fuzzy membership strength of nucleotides in each slide of window and filters nucleotides based on median filtering with a combination of s-shaped and z-shaped filters. Since coding regions cause 3-base periodicity by an unbalanced nucleotides' distribution producing a relatively high bias for nucleotides' usage, such fundamental characteristic of nucleotides has been exploited in FAWMF to suppress the signal noise. Along with adaptive response of FAWMF, a strong correlation between median nucleotides and the Π shaped filter was observed which produced enhanced discrimination between coding and non-coding regions contrary to fixed length conventional window filters. The proposed FAWMF attains a significant enhancement in coding regions identification i.e. 40% to 125% as compared to other conventional window filters tested over more than 250 benchmarked and randomly taken DNA datasets of different organisms. This study proves that conventional fixed length window filters applied to DNA signals do not achieve significant results since the nucleotides carry genetic code context. The proposed FAWMF algorithm is adaptive and outperforms significantly to process DNA signal contents. The algorithm applied to variety of DNA datasets produced noteworthy discrimination between coding and non-coding regions contrary

Neural Entrainment to Auditory Imagery of Rhythms.

PubMed

Okawa, Haruki; Suefusa, Kaori; Tanaka, Toshihisa

2017-01-01

A method of reconstructing perceived or imagined music by analyzing brain activity has not yet been established. As a first step toward developing such a method, we aimed to reconstruct the imagery of rhythm, which is one element of music. It has been reported that a periodic electroencephalogram (EEG) response is elicited while a human imagines a binary or ternary meter on a musical beat. However, it is not clear whether or not brain activity synchronizes with fully imagined beat and meter without auditory stimuli. To investigate neural entrainment to imagined rhythm during auditory imagery of beat and meter, we recorded EEG while nine participants (eight males and one female) imagined three types of rhythm without auditory stimuli but with visual timing, and then we analyzed the amplitude spectra of the EEG. We also recorded EEG while the participants only gazed at the visual timing as a control condition to confirm the visual effect. Furthermore, we derived features of the EEG using canonical correlation analysis (CCA) and conducted an experiment to individually classify the three types of imagined rhythm from the EEG. The results showed that classification accuracies exceeded the chance level in all participants. These results suggest that auditory imagery of meter elicits a periodic EEG response that changes at the imagined beat and meter frequency even in the fully imagined conditions. This study represents the first step toward the realization of a method for reconstructing the imagined music from brain activity.

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

PubMed

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.

"Bird Song Metronomics": Isochronous Organization of Zebra Finch Song Rhythm.

PubMed

Norton, Philipp; Scharff, Constance

2016-01-01

The human capacity for speech and vocal music depends on vocal imitation. Songbirds, in contrast to non-human primates, share this vocal production learning with humans. The process through which birds and humans learn many of their vocalizations as well as the underlying neural system exhibit a number of striking parallels and have been widely researched. In contrast, rhythm, a key feature of language, and music, has received surprisingly little attention in songbirds. Investigating temporal periodicity in bird song has the potential to inform the relationship between neural mechanisms and behavioral output and can also provide insight into the biology and evolution of musicality. Here we present a method to analyze birdsong for an underlying rhythmic regularity. Using the intervals from one note onset to the next as input, we found for each bird an isochronous sequence of time stamps, a "signal-derived pulse," or pulse(S), of which a subset aligned with all note onsets of the bird's song. Fourier analysis corroborated these results. To determine whether this finding was just a byproduct of the duration of notes and intervals typical for zebra finches but not dependent on the individual duration of elements and the sequence in which they are sung, we compared natural songs to models of artificial songs. Note onsets of natural song deviated from the pulse(S) significantly less than those of artificial songs with randomized note and gap durations. Thus, male zebra finch song has the regularity required for a listener to extract a perceived pulse (pulse(P)), as yet untested. Strikingly, in our study, pulses(S) that best fit note onsets often also coincided with the transitions between sub-note elements within complex notes, corresponding to neuromuscular gestures. Gesture durations often equaled one or more pulse(S) periods. This suggests that gesture duration constitutes the basic element of the temporal hierarchy of zebra finch song rhythm, an interesting parallel

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

PubMed

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.

Recognizing an Irregular Heart Rhythm

MedlinePlus

... a workout, consider checking your rhythm as well. Atrial fibrillation, also referred to as AF, is a common ... upper chambers, or atria, of the heart. “While atrial fibrillation is not common among young people, it can ...

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

PubMed

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 (p<.001). Infants demonstrated a developmental trajectory of circadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (p<.001). By 12 weeks, infant phase advancement was evidenced by mean acrophase and M10 midpoint occurring 60 and 43 min (respectively) earlier than at 4 weeks. While maternal acrophase remained consistent over time, infants became increasingly phase advanced relative to mother and mean infant acrophase at 12 weeks occurred 60 min before mother. Mother-infant synchrony was evidenced in increasing correspondence of acrophase at 12 weeks (r=0.704), L5 (r=0.453) and M10 (r=0.479) midpoints. Development of mother-infant synchrony reflects shared elements of circadian rhythm. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Mother-Infant Circadian Rhythm: Development of Individual Patterns and Dyadic Synchrony

PubMed Central

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

2014-01-01

Background Mutual circadian rhythm is an early and essential component in the development of maternal-infant physiological synchrony. Aims To examine the longitudinal pattern of maternal-infant circadian rhythm and rhythm synchrony as measured by rhythm parameters. Study Design In-home dyadic actigraphy monitoring at infant age 4, 8, and 12 weeks. Subjects Forty-three healthy mother-infant pairs. Outcome Measures Circadian parameters derived from cosinor and non-parametric analysis including mesor, magnitude, acrophase, L5 and M10 midpoints (midpoint of lowest 5 and highest 10 hours of activity), amplitude, interdaily stability (IS), and intradaily variability (IV). Results 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 (p < .001). Infants demonstrated a developmental trajectory of circadian pattern with significant time effects for increasing mesor, magnitude, amplitude, L5, IS, and IV (p < .001). By 12 weeks, infant phase advancement was evidenced by mean acrophase and M10 midpoint occurring 60 and 43 minutes (respectively) earlier than at 4 weeks. While maternal acrophase remained consistent over time, infants became increasingly phase advanced relative to mother and mean infant acrophase at 12 weeks occurred 60 minutes before mother. Mother-infant synchrony was evidenced in increasing correspondence of acrophase at 12 weeks (r = 0.704), L5 (r = 0.453) and M10 (r = 0.479) midpoints. Conclusions Development of mother-infant synchrony reflects shared elements of circadian rhythm. PMID:25463836

Rhythm as an affordance for the entrainment of movement.

PubMed

Cummins, Fred

2009-01-01

A general account of rhythm in human behaviour is provided, according to which rhythm inheres in the affordance that a signal provides for the entrainment of movement on the part of a perceiver. This generic account is supported by an explication of the central concepts of affordance and entrainment. When viewed in this light, rhythm appears as the correct explanandum to account for coordinated behaviour in a wide variety of situations, including such core senses as dance and the production of music. Speech may appear to be only marginally rhythmical under such an account, but several experimental studies reveal that speech, too, has the potential to entrain movement. (c) 2009 S. Karger AG, Basel.

Circadian Rhythms in Diet-Induced Obesity.

PubMed

Engin, Atilla

2017-01-01

The biological clocks of the circadian timing system coordinate cellular and physiological processes and synchronizes these with daily cycles, feeding patterns also regulates circadian clocks. The clock genes and adipocytokines show circadian rhythmicity. Dysfunction of these genes are involved in the alteration of these adipokines during the development of obesity. Food availability promotes the stimuli associated with food intake which is a circadian oscillator outside of the suprachiasmatic nucleus (SCN). Its circadian rhythm is arranged with the predictable daily mealtimes. Food anticipatory activity is mediated by a self-sustained circadian timing and its principal component is food entrained oscillator. However, the hypothalamus has a crucial role in the regulation of energy balance rather than food intake. Fatty acids or their metabolites can modulate neuronal activity by brain nutrient-sensing neurons involved in the regulation of energy and glucose homeostasis. The timing of three-meal schedules indicates close association with the plasma levels of insulin and preceding food availability. Desynchronization between the central and peripheral clocks by altered timing of food intake and diet composition can lead to uncoupling of peripheral clocks from the central pacemaker and to the development of metabolic disorders. Metabolic dysfunction is associated with circadian disturbances at both central and peripheral levels and, eventual disruption of circadian clock functioning can lead to obesity. While CLOCK expression levels are increased with high fat diet-induced obesity, peroxisome proliferator-activated receptor (PPAR) alpha increases the transcriptional level of brain and muscle ARNT-like 1 (BMAL1) in obese subjects. Consequently, disruption of clock genes results in dyslipidemia, insulin resistance and obesity. Modifying the time of feeding alone can greatly affect body weight. Changes in the circadian clock are associated with temporal alterations in

Circadian rhythms of women with fibromyalgia

NASA Technical Reports Server (NTRS)

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.

[Biological experiments on "Kosmos-1887"].

PubMed

Alpatov, A M; I'lin, E A; Antipov, V V; Tairbekov, M G

1989-01-01

In the 13-ray space flight on Kosmos-1887 various experiments in the field of cell biology, genetics, biorhythm, developmental biology and regeneration were performed using bacteria, protozoa, plants, worms, insects, fish and amphibia. Paramecia showed enhanced cell proliferation, spheroidization and diminished protein content. Experiments on fruit-flies, newt oocytes and primate lymphocytes confirmed involvement of the cell genetic apparatus in responses to microgravity. Beetles exhibited a reduction of the length of the spontaneous period of freely running circadian rhythms. Carausius morosus developed latent changes in early embryogenesis which manifested at later stages of ontogenesis. Exposure to microgravity did not prevent recovery of injured tissues; moreover their regeneration may be accelerated after recovery. Biology research programs in future biosatellite flights are discussed.

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

PubMed Central

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

USDA-ARS?s Scientific Manuscript database

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...

Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

PubMed

Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

2015-01-01

Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Effect of rhythm on the recovery from intense exercise.

PubMed

Eliakim, Michal; Bodner, Ehud; Meckel, Yoav; Nemet, Dan; Eliakim, Alon

2013-04-01

Motivational music (music that stimulates physical activity) was previously shown to enhance the recovery from intense exercise. The aim of the present study was to isolate the effect of rhythm (presumed to be the most effective factor of motivational music) on the recovery from intense exercise. Ten young adult active men (age: 26.1 ± 1.7 years) performed 6-minute run at peak oxygen consumption speed, at 3 separate visits (random order). At 1 visit, no music was played during the recovery after exercise. In the other visits, participants listened to motivational music that was previously shown to enhance recovery (a Western CD collection of greatest hits of all times converted to dance style, 140 b·min, strong bit, played by portable MP3 device using headphones at a volume of 70 dB) or only to the rhythm beats derived from the same songs. Mean heart rate (HR), rating of perceived exertion (RPE), number of steps (measured by step counter) and blood lactate concentrations were determined at 3, 6, 9, 12, and 15 minutes of the recovery. There was no difference in HR changes during the recovery at all conditions. Compared with the recovery without music, listening to motivational music during recovery was associated with significant greater number of steps, lower absolute lactate levels, and greater mean decrease of RPE. Listening only to rhythm beats, derived from the same music, during the recovery was associated with significant greater number of steps and lower absolute lactate levels compared to recovery without music. Music was significantly more effective than rhythm only in the absolute mean number of steps. The beneficial effect of both music and rhythm was greater toward the end of the recovery period. Results suggest that listening to music during nonstructured recovery can be used by professional athletes to enhance recovery from intense exercise. Rhythm plays a very important role in the effect of music on recovery and can be used to enhance

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

PubMed

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.

Entrainment of circadian rhythms to irregular light/dark cycles: a subterranean perspective

PubMed Central

Flôres, Danilo E. F. L.; Jannetti, Milene G.; Valentinuzzi, Veronica S.; Oda, Gisele A.

2016-01-01

Synchronization of biological rhythms to the 24-hour day/night has long been studied with model organisms, under artificial light/dark cycles in the laboratory. The commonly used rectangular light/dark cycles, comprising hours of continuous light and darkness, may not be representative of the natural light exposure for most species, including humans. Subterranean rodents live in dark underground tunnels and offer a unique opportunity to investigate extreme mechanisms of photic entrainment in the wild. Here, we show automated field recordings of the daily light exposure patterns in a South American subterranean rodent, the tuco-tuco (Ctenomys aff. knighti ). In the laboratory, we exposed tuco-tucos to a simplified version of this natural light exposure pattern, to determine the minimum light timing information that is necessary for synchronization. As predicted from our previous studies using mathematical modeling, the activity rhythm of tuco-tucos synchronized to this mostly simplified light/dark regimen consisting of a single light pulse per day, occurring at randomly scattered times within a day length interval. Our integrated semi-natural, lab and computer simulation findings indicate that photic entrainment of circadian oscillators is robust, even in face of artificially reduced exposure and increased phase instability of the synchronizing stimuli. PMID:27698436

The circadian rhythm of core temperature: effects of physical activity and aging.

PubMed

Weinert, Dietmar; Waterhouse, Jim

2007-02-28

The circadian rhythm of core temperature depends upon several interacting rhythms, of both endogenous and exogenous origin, but an understanding of the process requires these two components to be separated. Constant routines remove the exogenous (masking) component at source, but they are severely limited in their application. By contrast, several purification methods have successfully reduced the masking component of overt circadian rhythms measured in field circumstances. One important, but incidental, outcome from these methods is that they enable a quantitative estimate of masking effects to be obtained. It has been shown that these effects of activity upon the temperature rhythm show circadian rhythmicity, and more detailed investigations of this have aided our understanding of thermoregulation and the genesis of the circadian rhythm of core temperature itself. The observed circadian rhythm of body temperature varies with age; in comparison with adults, it is poorly developed in the neonate and deteriorates in the aged subject. Comparing masked and purified data enables the reasons for these differences--whether due to the body clock, the effector pathways or organs, or irregularities due to the individual's lifestyle--to begin to be understood. Such investigations stress the immaturity of the circadian rhythm in the human neonate and its deterioration in elderly compared with younger subjects, but they also indicate the robustness of the body clock itself into advanced age, at least in mice.

[Circadian rhythm disruption and human development].

PubMed

Kohyama, Jun

2013-12-01

Ontogenetic developments of rest-activity, sleep-wakefulness, temperature and several hormone rhythms in humans were reviewed. The reported effects of environment on these alterations were also summarized. Then, disorders or conditions which often encounter during early stage of life and reveal circadian rhythm disruptions were described. These disorders or conditions included severe brain damage, visual disturbance, developmental disorders(autistic spectrum disorder and attention deficit/hyperactivity disorder), Rett syndrome, Angelman syndrome, Smith-Magenis syndrome, epilepsy, Yonaki, and inadequate sleep hygiene. Finally, it was emphasized that we should pay special attention on the development of youngsters who showed sleep disturbance during early stage of life with special reference to the later occurrence of developmental disorders.

Rhythms can overcome temporal orienting deficit after right frontal damage.

PubMed

Triviño, Mónica; Arnedo, Marisa; Lupiáñez, Juan; Chirivella, Javier; Correa, Angel

2011-12-01

The main aim of this study was to test whether the use of rhythmic information to induce temporal expectations can overcome the deficit in controlled temporal preparation shown by patients with frontal damage (i.e. temporal orienting and foreperiod effects). Two tasks were administered to a group of 15 patients with a frontal brain lesion and a group of 15 matched control subjects: a Symbolic Cued Task where the predictive information regarding the time of target appearance was provided by a symbolic cue (short line-early vs. long line-late interval) and a Rhythm Cued Task where the predictive temporal information was provided by a rhythm (fast rhythm-early vs. slow rhythm-late interval). The results of the Symbolic Cued Task replicated both the temporal orienting deficit in right frontal patients and the absence of foreperiod effects in both right and left frontal patients, reported in our previous study (Triviño, Correa, Arnedo, & Lupiañez, 2010). However, in the Rhythm Cued Task, the right frontal group showed normal temporal orienting and foreperiod effects, while the left frontal group showed a significant deficit of both effects. These findings show that automatic temporal preparation, as induced by a rhythm, can help frontal patients to make effective use of implicit temporal information to respond at the optimum time. Our neuropsychological findings also provide a novel suggestion for a neural model, in which automatic temporal preparation is left-lateralized and controlled temporal preparation is right-lateralized in the frontal lobes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Circadian Rest-Activity Rhythm in Pediatric Type 1 Narcolepsy

PubMed Central

Filardi, Marco; Pizza, Fabio; Bruni, Oliviero; Natale, Vincenzo; Plazzi, Giuseppe

2016-01-01

Study Objectives: Pediatric type 1 narcolepsy is often challenging to diagnose and remains largely undiagnosed. Excessive daytime sleepiness, disrupted nocturnal sleep, and a peculiar phenotype of cataplexy are the prominent features. The knowledge available about the regulation of circadian rhythms in affected children is scarce. This study compared circadian rest-activity rhythm and actigraphic estimated sleep measures of children with type 1 narcolepsy versus healthy controls. Methods: Twenty-two drug-naïve type 1 narcolepsy children and 21 age- and sex- matched controls were monitored for seven days during the school week by actigraphy. Circadian activity rhythms were analyzed through functional linear modeling; nocturnal and diurnal sleep measures were estimated from activity using a validated algorithm. Results: Children with type 1 narcolepsy presented an altered rest-activity rhythm characterized by enhanced motor activity throughout the night and blunted activity in the first afternoon. No difference was found between children with type 1 narcolepsy and controls in the timing of the circadian phase. Actigraphic sleep measures showed good discriminant capabilities in assessing type 1 narcolepsy nycthemeral disruption. Conclusions: Actigraphy reliably renders the nycthemeral disruption typical of narcolepsy type 1 in drug-naïve children with recent disease onset, indicating the sensibility of actigraphic assessment in the diagnostic work-up of childhood narcolepsy type 1. Citation: Filardi M, Pizza F, Bruni O, Natale V, Plazzi G. Circadian rest-activity rhythm in pediatric type 1 narcolepsy. SLEEP 2016;39(6):1241–1247. PMID:27091539

Circadian Rhythm Sleep Disorders: Part II, Advanced Sleep Phase Disorder, Delayed Sleep Phase Disorder, Free-Running Disorder, and Irregular Sleep-Wake Rhythm

PubMed Central

Sack, Robert L; Auckley, Dennis; Auger, R. Robert; Carskadon, Mary A.; Wright, Kenneth P.; Vitiello, Michael V.; Zhdanova, Irina V.

2007-01-01

Objective: This the second of two articles reviewing the scientific literature on the evaluation and treatment of circadian rhythm sleep disorders (CRSDs), employing the methodology of evidence-based medicine. We herein report on the accumulated evidence regarding the evaluation and treatment of Advamced Sleep Phase Disorder (ASPD), Delayed Sleep Phase Disorder (DSPD), Free-Running Disorder (FRD) and Irregular Sleep-Wake Rhythm ISWR). Methods: A set of specific questions relevant to clinical practice were formulated, a systematic literature search was performed, and relevant articles were abstracted and graded. Results: A substantial body of literature has accumulated that provides a rational basis the evaluation and treatment of CRSDs. Physiological assessment has involved determination of circadian phase using core body temperature and the timing of melatonin secretion. Behavioral assessment has involved sleep logs, actigraphy and the Morningness-Eveningness Questionnaire (MEQ). Treatment interventions fall into three broad categories: 1) prescribed sleep scheduling, 2) circadian phase shifting (“resetting the clock”), and 3) symptomatic treatment using hypnotic and stimulant medications. Conclusion: Circadian rhythm science has also pointed the way to rational interventions for CRSDs and these treatments have been introduced into the practice of sleep medicine with varying degrees of success. More translational research is needed using subjects who meet current diagnostic criteria. Citation: Sack R; Auckley D; Auger RR; Carskadon MA; Wright KP; Vitiello MV; Zhdanova IV. Circadian rhythm sleep disorders: Part II, advanced sleep phase disorder, delayed sleep phase disorder, free-running disorder, and irregular sleep-wake rhythm. SLEEP 2007;30(11):1484-1501. PMID:18041481

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

PubMed

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.

Respiratory modulation of human autonomic rhythms

NASA Technical Reports Server (NTRS)

Badra, L. J.; Cooke, W. H.; Hoag, J. B.; Crossman, A. A.; Kuusela, T. A.; Tahvanainen, K. U.; Eckberg, D. L.

2001-01-01

We studied the influence of three types of breathing [spontaneous, frequency controlled (0.25 Hz), and hyperventilation with 100% oxygen] and apnea on R-R interval, photoplethysmographic arterial pressure, and muscle sympathetic rhythms in nine healthy young adults. We integrated fast Fourier transform power spectra over low (0.05-0.15 Hz) and respiratory (0.15-0.3 Hz) frequencies; estimated vagal baroreceptor-cardiac reflex gain at low frequencies with cross-spectral techniques; and used partial coherence analysis to remove the influence of breathing from the R-R interval, systolic pressure, and muscle sympathetic nerve spectra. Coherence among signals varied as functions of both frequency and time. Partialization abolished the coherence among these signals at respiratory but not at low frequencies. The mode of breathing did not influence low-frequency oscillations, and they persisted during apnea. Our study documents the independence of low-frequency rhythms from respiratory activity and suggests that the close correlations that may exist among arterial pressures, R-R intervals, and muscle sympathetic nerve activity at respiratory frequencies result from the influence of respiration on these measures rather than from arterial baroreflex physiology. Most importantly, our results indicate that correlations among autonomic and hemodynamic rhythms vary over time and frequency, and, thus, are facultative rather than fixed.

Circadian rhythm of body temperature in an ectotherm (Iguana iguana).

PubMed

Tosini, G; Menaker, M

1995-09-01

Ectothermic animals regulate their body temperatures primarily by behavioral adjustment in relation to the thermal characteristics of the environment. Several studies have shown that some vertebrate ectotherms may show a daily pattern of body temperature selection when given a choice of environmental temperature. The pattern of body temperature selection free-runs when the animals are kept in constant darkness, demonstrating the existence of circadian regulation. To test whether there might also be a low amplitude circadian rhythm of body temperature itself, we examined the pattern of body temperature and locomotor activity of the lizard Iguana iguana held in a constant environmental temperature. Both variables were recorded for 3 days in a light:dark cycle and then for 10 days in constant dim light (0.1 lux). Under these conditions the body temperature of the lizard oscillates with a circadian period as does the locomotor behavior. These results demonstrate for the first time that ectothermic animals may display physiologically generated circadian rhythms of body temperature similar to those recorded in endotherms. In some animals the circadian rhythms of body temperature and locomotor activity showed different free-running periods, demonstrating that the body temperature rhythm was not caused by locomotor activity and suggesting internal desyncronization of the two rhythms.

Lateralized ultradian rhythms: evidence from tactile discrimination of either hand.

PubMed

Meier-Koll, A

1998-12-01

Endogenous ultradian rhythms with periods of one or a few hours affect not only on physiological and behavioural functions but also perception and cognition. In particular, lateralized ultradian rhythms which seem to operate separately in the right and left hemispheres of the brain can be monitored by testing the tactile discrimination of the contralateral hand. The present paper is based on two subsequent studies: First, ultradian rhythms in tactile discrimination of either hand were examined in German subjects under laboratory conditions. Considerably different ultradian periods of right and left-handed tactile error rate were found in men but not in women. In a second study, a group of Kenyan Masai shepherds were tested while the subjects were leading herds on daily feeding routes through a savanna habitat. They showed ultradian periods of about 2 hours in tactile discrimination of either hand. Since the right hemisphere is specialized for visuospatial, the left for verbal processing lateralized ultradian rhythms may serve for a long-scale timing of neural processes underlying spatial and semantic mapping of the environment. Sex difference in German subjects and lateral differences found in left-handed (right-hemispheric) ultradian rhythms of German and Masai subjects are discussed from this point of view.

Practice parameters for the clinical evaluation and treatment of circadian rhythm sleep disorders. An American Academy of Sleep Medicine report.

PubMed

Morgenthaler, Timothy I; Lee-Chiong, Teofilo; Alessi, Cathy; Friedman, Leah; Aurora, R Nisha; Boehlecke, Brian; Brown, Terry; Chesson, Andrew L; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J; Zak, Rochelle

2007-11-01

The expanding science of circadian rhythm biology and a growing literature in human clinical research on circadian rhythm sleep disorders (CRSDs) prompted the American Academy of Sleep Medicine (AASM) to convene a task force of experts to write a review of this important topic. Due to the extensive nature of the disorders covered, the review was written in two sections. The first review paper, in addition to providing a general introduction to circadian biology, addresses "exogenous" circadian rhythm sleep disorders, including shift work disorder (SWD) and jet lag disorder (JLD). The second review paper addresses the "endogenous" circadian rhythm sleep disorders, including advanced sleep phase disorder (ASPD), delayed sleep phase disorder (DSPD), irregular sleep-wake rhythm (ISWR), and the non-24-hour sleep-wake syndrome (nonentrained type) or free-running disorder (FRD). These practice parameters were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the AASM to present recommendations for the assessment and treatment of CRSDs based on the two accompanying comprehensive reviews. The main diagnostic tools considered include sleep logs, actigraphy, the Morningness-Eveningness Questionnaire (MEQ), circadian phase markers, and polysomnography. Use of a sleep log or diary is indicated in the assessment of patients with a suspected circadian rhythm sleep disorder (Guideline). Actigraphy is indicated to assist in evaluation of patients suspected of circadian rhythm disorders (strength of recommendation varies from "Option" to "Guideline," depending on the suspected CRSD). Polysomnography is not routinely indicated for the diagnosis of CRSDs, but may be indicated to rule out another primary sleep disorder (Standard). There is insufficient evidence to justify the use of MEQ for the routine clinical evaluation of CRSDs (Option). Circadian phase markers are useful to determine circadian phase and confirm the diagnosis of

Cross-modal perception of rhythm in music and dance by cochlear implant users.

PubMed

Vongpaisal, Tara; Monaghan, Melanie

2014-05-01

Two studies examined adult cochlear implant (CI) users' ability to match auditory rhythms occurring in music to visual rhythms occurring in dance (Cha Cha, Slow Swing, Tango and Jive). In Experiment 1, adults CI users (n = 10) and hearing controls matched a music excerpt to choreographed dance sequences presented as silent videos. In Experiment 2, participants matched a silent video of a dance sequence to music excerpts. CI users were successful in detecting timing congruencies across music and dance at well above-chance levels suggesting that they were able to process distinctive auditory and visual rhythm patterns that characterized each style. However, they were better able to detect cross-modal timing congruencies when the reference was an auditory rhythm than when the reference was a visual rhythm. Learning strategies that encourage cross-modal learning of musical rhythms may have applications in developing novel rehabilitative strategies to enhance music perception and appreciation outcomes of child implant users.

Retinoic Acid-Related Orphan Receptors (RORs): Regulatory Functions in Immunity, Development, Circadian Rhythm, and Metabolism

PubMed Central

Cook, Donald N.; Kang, Hong Soon; Jetten, Anton M.

2015-01-01

In this overview, we provide an update on recent progress made in understanding the mechanisms of action, physiological functions, and roles in disease of retinoic acid related orphan receptors (RORs). We are particularly focusing on their roles in the regulation of adaptive and innate immunity, brain function, retinal development, cancer, glucose and lipid metabolism, circadian rhythm, metabolic and inflammatory diseases and neuropsychiatric disorders. We also summarize the current status of ROR agonists and inverse agonists, including their regulation of ROR activity and their therapeutic potential for management of various diseases in which RORs have been implicated. PMID:26878025

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

NASA Astrophysics Data System (ADS)

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.

Correlation of the Hippocampal theta rhythm to changes in hypothalamic temperature

NASA Technical Reports Server (NTRS)

Saleh, M. A.; Horowitz, J. M.; Hsieh, A. C. L.

1974-01-01

Warming and cooling the preoptic anterior hypothalamic area in awake, loosely restrained rabbits was found to evoke theta rhythm. This is consistent with previous studies indicating that theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Several studies have correlated theta rhythm with alertness. A neural pathway involving the hypothalamus, the hippocampus, the septal area, and the reticular formation is proposed. Thus, a role of this pathway may be to alert the animal to changes in its body temperature.

Neurospora circadian rhythms in space - A reexamination of the endogenous-exogenous question

NASA Technical Reports Server (NTRS)

Sulzman, F. M.; Ellman, D.; Wassmer, G.; Fuller, C. A.; Moore-Ede, M.

1984-01-01

To test the functioning of circadian rhythms removed from periodicities of the earth's 24-hour rotation, the conidiation rhythm of the fungus Neurospora crassa was monitored in constant darkness during spaceflight. The free-running period of the rhythm was the same in space as on the earth, but there was a marked reduction in the clarity of the rhythm, and apparent arrhythmicity in some tubes. At the current stage of analysis of the results there is insufficient evidence to determine whether the effect seen in space was related to removal from 24-hour periodicities and whether the circadian timekeeping mechanism, or merely its expression, was affected.

Rhythm and timing in autism: learning to dance

PubMed Central

Amos, Pat

2013-01-01

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 relationship” 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 a time. PMID

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

NASA Technical Reports Server (NTRS)

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).

Impact of treatment crossovers on clinical outcomes in the rate and rhythm control strategies for atrial fibrillation: Insights from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial.

PubMed

Maan, Abhishek; Zhang, Zheng; Qin, Ziling; Wang, Yanbing; Dudley, Samuel; Dabhadakar, Kaustubh; Refaat, Marwan; Mansour, Moussa; Ruskin, Jeremy N; Heist, E Kevin

2017-07-01

We investigated the rates and reasons for crossover to alternative treatment strategies and its impact on mortality in patients who were enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. Over a mean follow-up period of 3.5 years, 842 patients underwent crossover to the alternative treatment arms in AFFIRM. The rate of crossover from rhythm to rate control (594/2,033, 29.2%) was more frequent than the rate of crossover from rate to rhythm control (248/2,027, 12.2%, P < 0.0001). The leading reasons for crossover from rhythm to rate control were failure to achieve or maintain sinus rhythm (272/594, 45.8%) and intolerable adverse effects (122/594, 20.5%). In comparison, the major reasons for crossover from rate to rhythm control were failure to control atrial fibrillation symptoms (159/248, 64.1%) and intolerable adverse effects (9/248, 3.6%). This difference in crossover pattern was statistically significant (P < 0.0001). There was a significantly decreased risk of all-cause mortality (adjusted HR: 0.61, 95% CI: 0.48-0.78, P < 0.0001) and cardiac mortality (adjusted hazard ratio [HR]: 0.61, 95% confidence interval [CI]: 0.43-0.88, P = 0.008) in the subgroup of patients who crossed over from rhythm to rate control as compared to those who continued in rhythm control. There was a nonsignificant trend toward decreased all-cause (adjusted HR: 0.76, 95% CI: 0.53-1.10, P = 0.14) and cardiac mortality (adjusted HR: 0.70, 95% CI: 0.42-1.18, P = 0.18) in patients who crossed over from rate to rhythm control as compared to those who continued rate control. © 2017 Wiley Periodicals, Inc.

Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD: implication for COPD-associated neuropathogenesis.

PubMed

Sundar, Isaac K; Yao, Hongwei; Huang, Yadi; Lyda, Elizabeth; Sime, Patricia J; Sellix, Michael T; Rahman, Irfan

2014-01-01

The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS) can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD) have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT) is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT) is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT) is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d), sub-chronic (10 d) or chronic (6 mo) CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase) and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD.

A Neocortical Delta Rhythm Facilitates Reciprocal Interlaminar Interactions via Nested Theta Rhythms

PubMed Central

Carracedo, Lucy M.; Kjeldsen, Henrik; Cunnington, Leonie; Jenkins, Alastair; Schofield, Ian; Cunningham, Mark O.; Davies, Ceri H.; Traub, Roger D.

2013-01-01

Delta oscillations (1–4 Hz) associate with deep sleep and are implicated in memory consolidation and replay of cortical responses elicited during wake states. A potent local generator has been characterized in thalamus, and local generators in neocortex have been suggested. Here we demonstrate that isolated rat neocortex generates delta rhythms in conditions mimicking the neuromodulatory state during deep sleep (low cholinergic and dopaminergic tone). The rhythm originated in an NMDA receptor-driven network of intrinsic bursting (IB) neurons in layer 5, activating a source of GABAB receptor-mediated inhibition. In contrast, regular spiking (RS) neurons in layer 5 generated theta-frequency outputs. In layer 2/3 principal cells, outputs from IB cells associated with IPSPs, whereas those from layer 5 RS neurons related to nested bursts of theta-frequency EPSPs. Both interlaminar spike and field correlations revealed a sequence of events whereby sparse spiking in layer 2/3 was partially reflected back from layer 5 on each delta period. We suggest that these reciprocal, interlaminar interactions may represent a “Helmholtz machine”-like process to control synaptic rescaling during deep sleep. PMID:23804097

Circadian rhythm asynchrony in man during hypokinesis.

NASA Technical Reports Server (NTRS)

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.

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

PubMed

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.

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

ERIC Educational Resources Information Center

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

NASA Technical Reports Server (NTRS)

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.

Circadian Rhythm Connections to Oxidative Stress: Implications for Human Health

PubMed Central

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

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

ERIC Educational Resources Information Center

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.…

InSync Adaptive Traffic Control System for the Veterans Memorial Hwy Corridor on Long Island, NY

DOT National Transportation Integrated Search

2012-08-01

This report documents Rhythm Engineerings adaptive traffic control system field installation performed : by New York State Department of Transportation (NYSDOT) along Veterans Memorial Hwy in Long : Island, NY. This report reviews the reason for t...

Rhythm sensitivity in macaque monkeys

PubMed Central

Selezneva, Elena; Deike, Susann; Knyazeva, Stanislava; Scheich, Henning; Brechmann, André; Brosch, Michael

2013-01-01

This study provides evidence that monkeys are rhythm sensitive. We composed isochronous tone sequences consisting of repeating triplets of two short tones and one long tone which humans perceive as repeating triplets of two weak and one strong beat. This regular sequence was compared to an irregular sequence with the same number of randomly arranged short and long tones with no such beat structure. To search for indication of rhythm sensitivity we employed an oddball paradigm in which occasional duration deviants were introduced in the sequences. In a pilot study on humans we showed that subjects more easily detected these deviants when they occurred in a regular sequence. In the monkeys we searched for spontaneous behaviors the animals executed concomitant with the deviants. We found that monkeys more frequently exhibited changes of gaze and facial expressions to the deviants when they occurred in the regular sequence compared to the irregular sequence. In addition we recorded neuronal firing and local field potentials from 175 sites of the primary auditory cortex during sequence presentation. We found that both types of neuronal signals differentiated regular from irregular sequences. Both signals were stronger in regular sequences and occurred after the onset of the long tones, i.e., at the position of the strong beat. Local field potential responses were also significantly larger for the durational deviants in regular sequences, yet in a later time window. We speculate that these temporal pattern-selective mechanisms with a focus on strong beats and their deviants underlie the perception of rhythm in the chosen sequences. PMID:24046732

Influence of light intensity and spectral composition of artificial light at night on melatonin rhythm and mRNA expression of gonadotropins in roach Rutilus rutilus.

PubMed

Brüning, Anika; Hölker, Franz; Franke, Steffen; Kleiner, Wibke; Kloas, Werner

2018-02-01

In this study we investigated the influence of artificial light at night (ALAN) of different intensities (0, 1, 10, 100 lx) and different colours (blue, green, red) on the daily melatonin rhythm and mRNA expression of gonadotropins in roach Rutilus rutilus, a ubiquitous cyprinid, which occur in standing and moderately flowing freshwater habitats of central Europe. Melatonin concentrations were significantly lowered under nocturnal white light already at 1 lx. Low intensity blue, green and red ALAN lowered the melatonin levels significantly in comparison to a dark control. We conclude that ALAN can disturb melatonin rhythms in roach at very low intensities and at different wavelengths and thus light pollution in urban waters has the potential to impact biological rhythms in fish. However, mRNA expression of gonadotropins was not affected by ALAN during the period of the experiments. Thus, suspected implications of ALAN on reproduction of roach could not be substantiated.

Temporal and Motor Representation of Rhythm in Fronto-Parietal Cortical Areas: An fMRI Study

PubMed Central

Konoike, Naho; Kotozaki, Yuka; Jeong, Hyeonjeong; Miyazaki, Atsuko; Sakaki, Kohei; Shinada, Takamitsu; Sugiura, Motoaki; Kawashima, Ryuta; Nakamura, Katsuki

2015-01-01

When sounds occur with temporally structured patterns, we can feel a rhythm. To memorize a rhythm, perception of its temporal patterns and organization of them into a hierarchically structured sequence are necessary. On the other hand, rhythm perception can often cause unintentional body movements. Thus, we hypothesized that rhythm information can be manifested in two different ways; temporal and motor representations. The motor representation depends on effectors, such as the finger or foot, whereas the temporal representation is effector-independent. We tested our hypothesis with a working memory paradigm to elucidate neuronal correlates of temporal or motor representation of rhythm and to reveal the neural networks associated with these representations. We measured brain activity by fMRI while participants memorized rhythms and reproduced them by tapping with the right finger, left finger, or foot, or by articulation. The right inferior frontal gyrus and the inferior parietal lobule exhibited significant effector-independent activations during encoding and retrieval of rhythm information, whereas the left inferior parietal lobule and supplementary motor area (SMA) showed effector-dependent activations during retrieval. These results suggest that temporal sequences of rhythm are probably represented in the right fronto-parietal network, whereas motor sequences of rhythm can be represented in the SMA-parietal network. PMID:26076024

Comparison of hormone and electrolyte circadian rhythms in male and female humans

NASA Technical Reports Server (NTRS)

Vernikos-Danellis, J.; Winget, C. M.; Goodwin, A. E.; Reilly, T.

1977-01-01

Circadian rhythm characteristics in healthy male and female humans were studied at 4-hour intervals for urine volume, cortisol, 5-hydroxyindoleacetic acid (5-HIAA), Na, K, Na/K ratios in the urine, as well as plasma cortisol. While plasma and urinary cortisol rhythms were very similar in both sexes, the described rhythms in urine volume, electrolyte, and 5-HIAA excretion differ for the two sexes. The results suggest that sex differences exist in the circadian patterns of important hormone and metabolic functions and that the internal synchrony of circadian rhythms differs for the two sexes. The results seem to indicate that the rhythmical secretion of cortisol does not account for the pattern of Na and K excretion.

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

PubMed

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.

Dopaminergic Regulation of Circadian Food Anticipatory Activity Rhythms in the Rat

PubMed Central

Smit, Andrea N.; Patton, Danica F.; Michalik, Mateusz; Opiol, Hanna; Mistlberger, Ralph E.

2013-01-01

Circadian activity rhythms are jointly controlled by a master pacemaker in the hypothalamic suprachiasmatic nuclei (SCN) and by food-entrainable circadian oscillators (FEOs) located elsewhere. The SCN mediates synchrony to daily light-dark cycles, whereas FEOs generate activity rhythms synchronized with regular daily mealtimes. The location of FEOs generating food anticipation rhythms, and the pathways that entrain these FEOs, remain to be clarified. To gain insight into entrainment pathways, we developed a protocol for measuring phase shifts of anticipatory activity rhythms in response to pharmacological probes. We used this protocol to examine a role for dopamine signaling in the timing of circadian food anticipation. To generate a stable food anticipation rhythm, rats were fed 3h/day beginning 6-h after lights-on or in constant light for at least 3 weeks. Rats then received the D2 agonist quinpirole (1 mg/kg IP) alone or after pretreatment with the dopamine synthesis inhibitor α-methylparatyrosine (AMPT). By comparison with vehicle injections, quinpirole administered 1-h before lights-off (19h before mealtime) induced a phase delay of activity onset prior to the next meal. Delay shifts were larger in rats pretreated with AMPT, and smaller following quinpirole administered 4-h after lights-on. A significant shift was not observed in response to the D1 agonist SKF81297. These results provide evidence that signaling at D2 receptors is involved in phase control of FEOs responsible for circadian food anticipatory rhythms in rats. PMID:24312417

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

PubMed

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.

Sleep and circadian rhythm disruption in neuropsychiatric illness.

PubMed

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.

The effect of lens aging and cataract surgery on circadian rhythm

PubMed Central

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. PMID:27500118

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

PubMed

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.

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

PubMed

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.

Diurnal rhythmicity in biological processes involved in bioavailability of functional food factors.

PubMed

Tsurusaki, Takashi; Sakakibara, Hiroyuki; Aoshima, Yoshiki; Yamazaki, Shunsuke; Sakono, Masanobu; Shimoi, Kayoko

2013-05-01

In the past few decades, many types of functional factors have been identified in dietary foods; for example, flavonoids are major groups widely distributed in the plant kingdom. However, the absorption rates of the functional food factors are usually low, and many of these are difficult to be absorbed in the intact forms because of metabolization by biological processes during absorption. To gain adequate beneficial effects, it is therefore mandatory to know whether functional food factors are absorbed in sufficient quantity, and then reach target organs while maintaining beneficial effects. These are the reasons why the bioavailability of functional food factors has been well investigated using rodent models. Recently, many of the biological processes have been reported to follow diurnal rhythms recurring every 24 h. Therefore, absorption and metabolism of functional food factors influenced by the biological processes may vary with time of day. Consequently, the evaluation of the bioavailability of functional food factors using rodent models should take into consideration the timing of consumption. In this review, we provide a perspective overview of the diurnal rhythm of biological processes involved in the bioavailability of functional food factors, particularly flavonoids.

Rhythm's Gonna Get You: Regular Meter Facilitates Semantic Sentence Processing

ERIC Educational Resources Information Center

Rothermich, Kathrin; Schmidt-Kassow, Maren; Kotz, Sonja A.

2012-01-01

Rhythm is a phenomenon that fundamentally affects the perception of events unfolding in time. In language, we define "rhythm" as the temporal structure that underlies the perception and production of utterances, whereas "meter" is defined as the regular occurrence of beats (i.e. stressed syllables). In stress-timed languages such as German, this…

Speech Rhythm: Its Relation to Performance Universals and Articulatory Timing

ERIC Educational Resources Information Center

Allen, George D.

1975-01-01

The relationship between the rhythms of spoken language and the rhythms of other human behavior is examined in terms of: (1) types of rhythmic structures observed, (2) rate of succession of rhythmic units, (3) a perceptual tendency equalization of physically unequal intervals, and (4) the variability of rhythmic motor action. (Author/RM)

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

PubMed

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.

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

PubMed

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, p<0.0001). Whole-day U(K)V/U(Na)V ratio (p=0.0007) and trans-tubular potassium concentration gradient (p=0.002) were attenuated but their night/day ratios remained unchanged. The change in the night/day U(K)V ratio correlated directly with the change in night/day U(Na)V ratio (F=20.4) rather than with the changes in aldosterone, BP or creatinine clearance. The circadian 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.

Persistent Parasitism: The Adaptive Biology of Malariae and Ovale Malaria.

PubMed

Sutherland, Colin J

2016-10-01

Plasmodium malariae causes malaria in humans throughout the tropics and subtropics. Plasmodium ovale curtisi and Plasmodium ovale wallikeri are sympatric sibling species common in sub-Saharan Africa and also found in Oceania and Asia. Although rarely identified as the cause of malaria cases in endemic countries, PCR detection has confirmed all three parasite species to be more prevalent, and persistent, than previously thought. Chronic, low-density, multispecies asymptomatic infection is a successful biological adaptation by these Plasmodium spp., a pattern also observed among malaria parasites of wild primates. Current whole-genome analyses are illuminating the species barrier separating the ovale parasite species and reveal substantial expansion of subtelomeric gene families. The evidence for and against a quiescent pre-erythrocytic form of P. malariae is reviewed. Copyright © 2016 Elsevier Ltd. All rights reserved.

“Bird Song Metronomics”: Isochronous Organization of Zebra Finch Song Rhythm

PubMed Central

Norton, Philipp; Scharff, Constance

2016-01-01

The human capacity for speech and vocal music depends on vocal imitation. Songbirds, in contrast to non-human primates, share this vocal production learning with humans. The process through which birds and humans learn many of their vocalizations as well as the underlying neural system exhibit a number of striking parallels and have been widely researched. In contrast, rhythm, a key feature of language, and music, has received surprisingly little attention in songbirds. Investigating temporal periodicity in bird song has the potential to inform the relationship between neural mechanisms and behavioral output and can also provide insight into the biology and evolution of musicality. Here we present a method to analyze birdsong for an underlying rhythmic regularity. Using the intervals from one note onset to the next as input, we found for each bird an isochronous sequence of time stamps, a “signal-derived pulse,” or pulseS, of which a subset aligned with all note onsets of the bird's song. Fourier analysis corroborated these results. To determine whether this finding was just a byproduct of the duration of notes and intervals typical for zebra finches but not dependent on the individual duration of elements and the sequence in which they are sung, we compared natural songs to models of artificial songs. Note onsets of natural song deviated from the pulseS significantly less than those of artificial songs with randomized note and gap durations. Thus, male zebra finch song has the regularity required for a listener to extract a perceived pulse (pulseP), as yet untested. Strikingly, in our study, pulsesS that best fit note onsets often also coincided with the transitions between sub-note elements within complex notes, corresponding to neuromuscular gestures. Gesture durations often equaled one or more pulseS periods. This suggests that gesture duration constitutes the basic element of the temporal hierarchy of zebra finch song rhythm, an interesting parallel to the

Subjective alertness rhythms in elderly people

NASA Technical Reports Server (NTRS)

Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Kupfer, D. J.; Houck, P. R.

1996-01-01

The aim of this study was to evaluate age-related changes in the circadian rhythm of subjective alertness and to explore the circadian mechanisms underlying such changes. Using a visual analogue scale (VAS) instrument, 25 older men and women (71 y and older; 15 female, 10 male) rated their subjective alertness about 7 times per day during 5 baseline days of temporal isolation during which habitual bedtimes and waketimes were enforced. Comparisons were made with 13 middle-aged men (37-52 y) experiencing the same protocol. Advancing age (particularly in the men) resulted in less rhythmic alertness patterns, as indicated by lower amplitudes and less reliability of fitted 24-h sinusoids. This appeared in spite of the absence of any reliable age-related diminution in circadian temperature rhythm amplitude, thus suggesting the effect was not due to SCN weakness per se, but to weakened transduction of SCN output. In a further experiment, involving 36 h of constant wakeful bedrest, differences in the amplitude of the alertness rhythm were observed between 9 older men (79 y+), 7 older women (79 y+), and 17 young controls (9 males, 8 females, 19-28 y) suggesting that with advancing age (particularly in men) there is less rhythmic input into subjective alertness from the endogenous circadian pacemaker. These results may explain some of the nocturnal insomnia and daytime hypersomnia that afflict many elderly people.

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

PubMed

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.

Role of diabetes in heart rhythm disorders

PubMed Central

Koektuerk, Buelent; Aksoy, Murat; Horlitz, Marc; Bozdag-Turan, Ilkay; Turan, Ramazan Goekmen

2016-01-01

The incidence of diabetes mellitus (DM) is increasing rapidly. DM is the leading cause of cardiovascular diseases, which can lead to varied cardiovascular complications by aggravated atherosclerosis in large arteries and coronary atherosclerosis, thereby grows the risk for macro and microangiopathy such as myocardial infarction, stroke, limb loss and retinopathy. Moreover diabetes is one of the strongest and independent risk factor for cardiovascular morbidity and mortality, which is associated frequently with rhythm disorders such as atrial fibrillation (AF) and ventricular arrhythmias (VA). The present article provides a concise overview of the association between DM and rhythm disorders such as AF and VA with underlying pathophysiological mechanisms. PMID:26862372

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

NASA Technical Reports Server (NTRS)

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.

Social rhythms of the heart

PubMed Central

Pantzar, Mika; Ruckenstein, Minna; Mustonen, Veera

2017-01-01

ABSTRACT A long-term research focus on the temporality of everyday life has become revitalised with new tracking technologies that allow methodological experimentation and innovation. This article approaches rhythms of daily lives with heart-rate variability measurements that use algorithms to discover physiological stress and recovery. In the spirit of the ‘social life of methods’ approach, we aggregated individual data (n = 35) in order to uncover temporal rhythms of daily lives. The visualisation of the aggregated data suggests both daily and weekly patterns. Daily stress was at its highest in the mornings and around eight o’clock in the evening. Weekend stress patterns were dissimilar, indicating a stress peak in the early afternoon especially for men. In addition to discussing our explorations using quantitative data, the more general aim of the article is to explore the potential of new digital and mobile physiological tracking technologies for contextualising the individual in the everyday. PMID:28163655

Temporal Interactions between Cortical Rhythms

PubMed Central

Roopun, Anita K.; Kramer, Mark A.; Carracedo, Lucy M.; Kaiser, Marcus; Davies, Ceri H.; Traub, Roger D.; Kopell, Nancy J.; Whittington, Miles A.

2008-01-01

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 co-active 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. PMID:19225587

Circadian rhythm dissociation in an environment with conflicting temporal information

NASA Technical Reports Server (NTRS)

Sulzman, F. M.; Fuller, C. A.; Hiles, L. G.; Moore-Ede, M. C.

1978-01-01

The relative contributions of light-dark (LD) cycles and eating-fasting (EF) cycles in providing temporal information to the circadian time-keeping system were examined in chair-acclimatized squirrel monkeys (Saimiri sciureus). The circadian rhythms of drinking, colonic temperature, urine volume, and urinary potassium excretion were measured with the LD and EF cycles providing either conflicting phases or periods. In conflicting phase experiments, animals were exposed to 24-hr LD cycles consisting of 12 hr of 600 lx followed by 12 hr of less than 1 lx and concurrent 24-hr EF cycles in which the animals ate for 3 hr and then fasted for 21 hr. One group had food available at the beginning and a second group at the end of the light period. In conflicting period experiments, monkeys were exposed to 23-hr LD cycles and 24-hr EF cycles. Analysis of the rhythms showed that both phase and period information were conveyed to the drinking and urinary rhythms by the EF cycle, and to the temperature rhythm by the LD cycle.

Perspectives on the rhythm-grammar link and its implications for typical and atypical language development.

PubMed

Gordon, Reyna L; Jacobs, Magdalene S; Schuele, C Melanie; McAuley, J Devin

2015-03-01

This paper reviews the mounting evidence for shared cognitive mechanisms and neural resources for rhythm and grammar. Evidence for a role of rhythm skills in language development and language comprehension is reviewed here in three lines of research: (1) behavioral and brain data from adults and children, showing that prosody and other aspects of timing of sentences influence online morpho-syntactic processing; (2) comorbidity of impaired rhythm with grammatical deficits in children with language impairment; and (3) our recent work showing a strong positive association between rhythm perception skills and expressive grammatical skills in young school-age children with typical development. Our preliminary follow-up study presented here revealed that musical rhythm perception predicted variance in 6-year-old children's production of complex syntax, as well as online reorganization of grammatical information (transformation); these data provide an additional perspective on the hierarchical relations potentially shared by rhythm and grammar. A theoretical framework for shared cognitive resources for the role of rhythm in perceiving and learning grammatical structure is elaborated on in light of potential implications for using rhythm-emphasized musical training to improve language skills in children. © 2015 New York Academy of Sciences.

Sleep, Memory & Brain Rhythms

PubMed Central

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. PMID:26097242