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Sample records for residual circadian system

  1. Circadian Systems and Metabolism

    NARCIS (Netherlands)

    Roenneberg, Till; Merrow, Martha

    1999-01-01

    Circadian systems direct many metabolic parameters and, at the same time, they appear to be exquisitely shielded from metabolic variations. Although the recent decade of circadian research has brought insights into how circadian periodicity may be generated at the molecular level, little is known

  2. Neurobiology of circadian systems.

    Science.gov (United States)

    Schulz, Pierre; Steimer, Thierry

    2009-01-01

    Time is a dimension tightly associated with the biology of living species. There are cycles of varied lengths in biological activities, from very short (ultradian) rhythms to rhythms with a period of approximately one day (circadian) and rhythms with longer cycles, of a week, a month, a season, or even longer. These rhythms are generated by endogenous biological clocks, i.e. time-keeping structures, rather than being passive reactions to external fluctuations. In mammals, the suprachiasmatic nucleus (SCN) is the major pacemaker. The pineal gland, which secretes melatonin, is the major pacemaker in other phyla. There also exist biological clocks generating circadian rhythms in peripheral tissues, for example the liver. A series of clock genes generates the rhythm through positive and negative feedback effect of proteins on their own synthesis, and this system oscillates with a circadian period. External factors serve as indicators of the astronomical (solar) time and are called zeitgebers, literally time-givers. Light is the major zeitgeber, which resets daily the SCN circadian clock. In the absence of zeitgebers, the circadian rhythm is said to be free running; it has a period that differs from 24 hours. The SCN, together with peripheral clocks, enables a time-related homeostasis, which can become disorganized in its regulation by external factors (light, social activities, food intake), in the coordination and relative phase position of rhythms, or in other ways. Disturbances of rhythms are found in everyday life (jet lag, shift work), in sleep disorders, and in several psychiatric disorders including affective disorders. As almost all physiological and behavioural functions in humans occur on a rhythmic basis, the possibility that advances, delays or desynchronization of circadian rhythms might participate in neurological and psychiatric disorders has been a theme of research. In affective disorders, a decreased circadian amplitude of several rhythms as well as a

  3. [Circadian rhythms and systems biology].

    Science.gov (United States)

    Goldbeter, Albert; Gérard, Claude; Leloup, Jean-Christophe

    2010-01-01

    Cellular rhythms represent a field of choice for studies in system biology. The examples of circadian rhythms and of the cell cycle show how the experimental and modeling approaches contribute to clarify the conditions in which periodic behavior spontaneously arises in regulatory networks at the cellular level. Circadian rhythms originate from intertwined positive and negative feedback loops controlling the expression of several clock genes. Models can be used to address the dynamical bases of physiological disorders related to dysfunctions of the mammalian circadian clock. The cell cycle is driven by a network of cyclin-dependent kinases (Cdks). Modeled in the form of four modules coupled through multiple regulatory interactions, the Cdk network operates in an oscillatory manner in the presence of sufficient amounts of growth factor. For circadian rhythms and the cell cycle, as for other recently observed cellular rhythms, periodic behavior represents an emergent property of biological systems related to their regulatory structure.

  4. Nutrition and the Circadian System

    Science.gov (United States)

    Potter, Gregory D M; Cade, Janet E; Grant, Peter J; Hardie, Laura J

    2016-01-01

    The human circadian system anticipates and adapts to daily environmental changes to optimise behaviour according to time of day and temporally partition incompatible physiological processes. At the helm of this system is a master clock in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. The SCN are primarily synchronised to the 24 hour day by the light/dark cycle; however, feeding/fasting cycles are the primary time cues for clocks in peripheral tissues. Aligning feeding/fasting cycles with clock-regulated metabolic changes optimises metabolism, and studies of other animals suggest that feeding at inappropriate times disrupts circadian system organisation and thereby contributes to adverse metabolic consequences and chronic disease development. ‘High-fat diets’ (HFDs) produce particularly deleterious effects on circadian system organisation in rodents by blunting feeding/fasting cycles. Time-of-day-restricted feeding, where food availability is restricted to a period of several hours, offsets many adverse consequences of HFDs in these animals; however, further evidence is required to assess whether the same is true in humans. Several nutritional compounds have robust effects on the circadian system. Caffeine, for example, can speed synchronisation to new time zones after jetlag. An appreciation of the circadian system has many implications for nutritional science and may ultimately help reduce the burden of chronic diseases. PMID:27221157

  5. Pyrethroid residue dynamics in insects depends on the circadian clock.

    Science.gov (United States)

    Maliszewska, Justyna; Piechowicz, Bartosz; Maciąga, Gabriela; Zaręba, Lech; Marcinkowska, Sonia

    2018-02-27

    Many factors may affect pesticide effectiveness against pests. One of the factors that should be considered is circadian rhythmicity. In this study, we evaluated daily variations in pyrethroid susceptibility in the house cricket, Acheta domesticus L. Crickets were exposed to a standard dose of ß-cyfluthrin at different times of a day, and pesticide residue levels were evaluated using gas chromatography. Results demonstrate that the time of pyrethroid disappearance is correlated with the circadian clock, with the highest decomposition rate at night. Furthermore, crickets also showed the highest resistance to the insecticide at night, expressed as a high survival rate. Moreover, ß-cyfluthrin induced significant changes in thermal preferences of intoxicated crickets. This is the first report showing that pyrethroid residue levels in the crickets' body depend on its circadian clock.

  6. Hierarchical organization of the circadian timing system

    OpenAIRE

    Steensel, Mariska van

    2006-01-01

    In order to cope with and to predict 24-hour rhythms in the environment, most, if not all, organisms have a circadian timing system. The most important mammalian circadian pacemaker is located in the suprachiasmatic nucleus at the base of the hypothalamus in the brain. Over the years, it has become clear that the circadian system is complex and that additional oscillators exist, both within and outside the central nervous system. The aim of this thesis was to obtain insight in the hierarchica...

  7. Hierarchical organization of the circadian timing system

    NARCIS (Netherlands)

    Steensel, Mariska van

    2006-01-01

    In order to cope with and to predict 24-hour rhythms in the environment, most, if not all, organisms have a circadian timing system. The most important mammalian circadian pacemaker is located in the suprachiasmatic nucleus at the base of the hypothalamus in the brain. Over the years, it has become

  8. Circadian Rhythm Management System Project

    Data.gov (United States)

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

  9. Nutrition and the circadian timing system

    NARCIS (Netherlands)

    Stenvers, Dirk Jan; Jonkers, Cora F.; Fliers, Eric; Bisschop, Peter H. L. T.; Kalsbeek, Andries

    2012-01-01

    Life on earth has evolved under the daily rhythm of light and dark. Consequently, most creatures experience a daily rhythm in food availability. In this review, we first introduce the mammalian circadian timing system, consisting of a central clock in the suprachiasmatic nucleus (SCN) and peripheral

  10. Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans.

    Science.gov (United States)

    Morris, Christopher J; Yang, Jessica N; Garcia, Joanna I; Myers, Samantha; Bozzi, Isadora; Wang, Wei; Buxton, Orfeu M; Shea, Steven A; Scheer, Frank A J L

    2015-04-28

    Glucose tolerance is lower in the evening and at night than in the morning. However, the relative contribution of the circadian system vs. the behavioral cycle (including the sleep/wake and fasting/feeding cycles) is unclear. Furthermore, although shift work is a diabetes risk factor, the separate impact on glucose tolerance of the behavioral cycle, circadian phase, and circadian disruption (i.e., misalignment between the central circadian pacemaker and the behavioral cycle) has not been systematically studied. Here we show--by using two 8-d laboratory protocols--in healthy adults that the circadian system and circadian misalignment have distinct influences on glucose tolerance, both separate from the behavioral cycle. First, postprandial glucose was 17% higher (i.e., lower glucose tolerance) in the biological evening (8:00 PM) than morning (8:00 AM; i.e., a circadian phase effect), independent of the behavioral cycle effect. Second, circadian misalignment itself (12-h behavioral cycle inversion) increased postprandial glucose by 6%. Third, these variations in glucose tolerance appeared to be explained, at least in part, by different mechanisms: during the biological evening by decreased pancreatic β-cell function (27% lower early-phase insulin) and during circadian misalignment presumably by decreased insulin sensitivity (elevated postprandial glucose despite 14% higher late-phase insulin) without change in early-phase insulin. We explored possible contributing factors, including changes in polysomnographic sleep and 24-h hormonal profiles. We demonstrate that the circadian system importantly contributes to the reduced glucose tolerance observed in the evening compared with the morning. Separately, circadian misalignment reduces glucose tolerance, providing a mechanism to help explain the increased diabetes risk in shift workers.

  11. Glaucoma alters the circadian timing system.

    Directory of Open Access Journals (Sweden)

    Elise Drouyer

    Full Text Available Glaucoma is a widespread ocular disease and major cause of blindness characterized by progressive, irreversible damage of the optic nerve. Although the degenerative loss of retinal ganglion cells (RGC and visual deficits associated with glaucoma have been extensively studied, we hypothesize that glaucoma will also lead to alteration of the circadian timing system. Circadian and non-visual responses to light are mediated by a specialized subset of melanopsin expressing RGCs that provide photic input to mammalian endogenous clock in the suprachiasmatic nucleus (SCN. In order to explore the molecular, anatomical and functional consequences of glaucoma we used a rodent model of chronic ocular hypertension, a primary causal factor of the pathology. Quantitative analysis of retinal projections using sensitive anterograde tracing demonstrates a significant reduction (approximately 50-70% of RGC axon terminals in all visual and non-visual structures and notably in the SCN. The capacity of glaucomatous rats to entrain to light was challenged by exposure to successive shifts of the light dark (LD cycle associated with step-wise decreases in light intensity. Although glaucomatous rats are able to entrain their locomotor activity to the LD cycle at all light levels, they require more time to re-adjust to a shifted LD cycle and show significantly greater variability in activity onsets in comparison with normal rats. Quantitative PCR reveals the novel finding that melanopsin as well as rod and cone opsin mRNAs are significantly reduced in glaucomatous retinas. Our findings demonstrate that glaucoma impacts on all these aspects of the circadian timing system. In light of these results, the classical view of glaucoma as pathology unique to the visual system should be extended to include anatomical and functional alterations of the circadian timing system.

  12. System identification of the Arabidopsis plant circadian system

    Science.gov (United States)

    Foo, Mathias; Somers, David E.; Kim, Pan-Jun

    2015-02-01

    The circadian system generates an endogenous oscillatory rhythm that governs the daily activities of organisms in nature. It offers adaptive advantages to organisms through a coordination of their biological functions with the optimal time of day. In this paper, a model of the circadian system in the plant Arabidopsis (species thaliana) is built by using system identification techniques. Prior knowledge about the physical interactions of the genes and the proteins in the plant circadian system is incorporated in the model building exercise. The model is built by using primarily experimentally-verified direct interactions between the genes and the proteins with the available data on mRNA and protein abundances from the circadian system. Our analysis reveals a great performance of the model in predicting the dynamics of the plant circadian system through the effect of diverse internal and external perturbations (gene knockouts and day-length changes). Furthermore, we found that the circadian oscillatory rhythm is robust and does not vary much with the biochemical parameters except those of a light-sensitive protein P and a transcription factor TOC1. In other words, the circadian rhythmic profile is largely a consequence of the network's architecture rather than its particular parameters. Our work suggests that the current experimental knowledge of the gene-to-protein interactions in the plant Arabidopsis, without considering any additional hypothetical interactions, seems to suffice for system-level modeling of the circadian system of this plant and to present an exemplary platform for the control of network dynamics in complex living organisms.

  13. Proteomics of the photoneuroendocrine circadian system of the brain

    DEFF Research Database (Denmark)

    Møller, Morten; Lund-Andersen, Casper; Rovsing, Louise

    2010-01-01

    The photoneuroendocrine circadian system of the brain consists of (a) specialized photoreceptors in the retina, (b) a circadian generator located in the forebrain that contains "clock genes," (c) specialized nuclei in the forebrain involved in neuroendocrine secretion, and (d) the pineal gland....../night variations in gene expression in the circadian system as well as in the whole brain and peripheral tissues have, during the last decade, been performed. However, studies of circadian changes in the proteome have been less investigated. In this survey, the anatomy and function of the circadian......-generating system in mammals is described, and recent proteomic studies that investigate day/night changes in the retina, SCN, and pineal gland are reviewed. Further circadian changes controlled by the SCN in gene and protein expression in the liver are discussed....

  14. Neuroendocrine underpinnings of sex differences in circadian timing systems.

    Science.gov (United States)

    Yan, Lily; Silver, Rae

    2016-06-01

    There are compelling reasons to study the role of steroids and sex differences in the circadian timing system. A solid history of research demonstrates the ubiquity of circadian changes that impact virtually all behavioral and biological responses. Furthermore, steroid hormones can modulate every attribute of circadian responses including the period, amplitude and phase. Finally, desynchronization of circadian rhythmicity, and either enhancing or damping amplitude of various circadian responses can produce different effects in the sexes. Studies of the neuroendocrine underpinnings of circadian timing systems and underlying sex differences have paralleled the overall development of the field as a whole. Early experimental studies established the ubiquity of circadian rhythms by cataloging daily and seasonal changes in whole organism responses. The next generation of experiments demonstrated that daily changes are not a result of environmental synchronizing cues, and are internally orchestrated, and that these differ in the sexes. This work was followed by the revelation of molecular circadian rhythms within individual cells. At present, there is a proliferation of work on the consequences of these daily oscillations in health and in disease, and awareness that these may differ in the sexes. In the present discourse we describe the paradigms used to examine circadian oscillation, to characterize how these internal timing signals are synchronized to local environmental conditions, and how hormones of gonadal and/or adrenal origin modulate circadian responses. Evidence pointing to endocrinologically and genetically mediated sex differences in circadian timing systems can be seen at many levels of the neuroendocrine and endocrine systems, from the cell, the gland and organ, and to whole animal behavior, including sleep/wake or rest/activity cycles, responses to external stimuli, and responses to drugs. We review evidence indicating that the analysis of the circadian

  15. Circadian profile of systemic hemodynamics

    NARCIS (Netherlands)

    Veerman, D. P.; Imholz, B. P.; Wieling, W.; Wesseling, K. H.; van Montfrans, G. A.

    1995-01-01

    We determined the continuous 24-hour profile of mean arterial pressure, heart rate, stroke volume, cardiac output, and total peripheral resistance in eight healthy ambulatory volunteers. Beat-to-beat intra-arterial blood pressure was recorded with the Oxford system; subjects were ambulant during

  16. Sex Differences in Circadian Timing Systems: Implications for Disease

    Science.gov (United States)

    Bailey, Matthew; Silver, Rae

    2014-01-01

    Virtually every eukaryotic cell has an endogenous circadian clock and a biological sex. These cell-based clocks have been conceptualized as oscillators whose phase can be reset by internal signals such as hormones, and external cues such as light. The present review highlights the inter-relationship between circadian clocks and sex differences. In mammals, the suprachiasmatic nucleus (SCN) serves as a master clock synchronizing the phase of clocks throughout the body. Gonadal steroid receptors are expressed in almost every site that receives direct SCN input. Here we review sex differences in the circadian timing system in the hypothalamic-pituitary-gonadal axis (HPG), the hypothalamicadrenal-pituitary (HPA) axis, and sleep-arousal systems. We also point to ways in which disruption of circadian rhythms within these systems differs in the sexes and is associated with dysfunction and disease. Understanding sex differentiated circadian timing systems can lead to improved treatment strategies for these conditions. PMID:24287074

  17. Circadian Rhythm Management System, Phase I

    Data.gov (United States)

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

  18. The importance of the circadian system & sleep for bone health.

    Science.gov (United States)

    Swanson, Christine M; Kohrt, Wendy M; Buxton, Orfeu M; Everson, Carol A; Wright, Kenneth P; Orwoll, Eric S; Shea, Steven A

    2017-12-09

    Adequate sleep timed appropriately during the circadian night is important for numerous biological processes and systems. New evidence suggests that both sleep timing and duration may be important for optimal bone health as well. This review examines the diurnal variation of bone turnover markers (BTMs) and the importance of circadian clock genes in regulating bone mass. In addition, this review explores the evidence for a link between shift work (and its associated disturbances in sleep duration/quality and circadian alignment) and alterations in bone metabolism and bone health. Finally, we review how commonly used medications and over-the-counter substances (e.g. caffeine, melatonin) complicate the relationship between sleep and circadian disorders and bone health. Copyright © 2017. Published by Elsevier Inc.

  19. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 11. Circadian Rhythms - Circadian Timing Systems: How are they Organized? Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 11 November 2013 pp 1032-1050 ...

  20. Circadian system from conception till adulthood

    Czech Academy of Sciences Publication Activity Database

    Sumová, Alena; Sládek, Martin; Polidarová, Lenka; Nováková, Marta; Houdek, Pavel

    2012-01-01

    Roč. 199, č. 2012 (2012), s. 83-103 ISSN 0079-6123 R&D Projects: GA ČR(CZ) GA305/09/0321; GA ČR(CZ) GAP303/11/0668; GA MŠk(CZ) LC554; GA MZd(CZ) NT11474; GA ČR(CZ) GAP303/12/1108 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : ontogenesis * suprachiasmatic nucleus * peripheral circadian clocks * clock gene Subject RIV: ED - Physiology Impact factor: 4.191, year: 2012

  1. Light, the circadian timing system, and type 2 diabetes

    NARCIS (Netherlands)

    Stenvers, D.J.

    2017-01-01

    Life evolved in conditions of a 24-hour rhythm of light and darkness, as dictated by the rotation of the earth. To prepare for the resulting behavioral rhythms of feeding/fasting and activity/sleep, mammals possess a circadian timing system, consisting of a central brain clock and peripheral clocks

  2. The role of the circadian system in fractal neurophysiological control.

    Science.gov (United States)

    Pittman-Polletta, Benjamin R; Scheer, Frank A J L; Butler, Matthew P; Shea, Steven A; Hu, Kun

    2013-11-01

    Many neurophysiological variables such as heart rate, motor activity, and neural activity are known to exhibit intrinsic fractal fluctuations - similar temporal fluctuation patterns at different time scales. These fractal patterns contain information about health, as many pathological conditions are accompanied by their alteration or absence. In physical systems, such fluctuations are characteristic of critical states on the border between randomness and order, frequently arising from nonlinear feedback interactions between mechanisms operating on multiple scales. Thus, the existence of fractal fluctuations in physiology challenges traditional conceptions of health and disease, suggesting that high levels of integrity and adaptability are marked by complex variability, not constancy, and are properties of a neurophysiological network, not individual components. Despite the subject's theoretical and clinical interest, the neurophysiological mechanisms underlying fractal regulation remain largely unknown. The recent discovery that the circadian pacemaker (suprachiasmatic nucleus) plays a crucial role in generating fractal patterns in motor activity and heart rate sheds an entirely new light on both fractal control networks and the function of this master circadian clock, and builds a bridge between the fields of circadian biology and fractal physiology. In this review, we sketch the emerging picture of the developing interdisciplinary field of fractal neurophysiology by examining the circadian system's role in fractal regulation. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

  3. Spectral sensitivity of the circadian system

    Science.gov (United States)

    Figueiro, Mariana G.; Bullough, John D.; Rea, Mark S.

    2004-01-01

    Light exposure regulates several circadian functions in normal humans including the sleep-wake cycle. Individuals with Alzheimer"s Disease (AD) often do not have regular patterns of activity and rest, but, rather, experience random periods of sleep and agitation during both day and night. Bright light during the day and darkness at night has been shown to consolidate activity periods during the day and rest periods at night in AD patients. The important characteristics of bright light exposure (quantity, spectrum, distribution, timing and duration) for achieving these results in AD patients is not yet understood. Recent research has shown that moderate (~18 lx at the cornea) blue (~470 nm) light is effective at suppressing melatonin in normal humans. It was hypothesized that blue light applied just before AD patients retire to their beds for the night would have a measurable impact on their behavior. A pilot study was conducted for 30 days in a senior health care facility using four individuals diagnosed with mild to moderate levels of dementia. Four AD patients were exposed to arrays of blue light from light emitting diodes (max wavelength = 470 nm) in two-hour sessions (18:00 to 20:00 hours) for 10 days. As a control, they were exposed to red light (max wavelength = 640 nm) in two-hour sessions for 10 days prior to the blue light exposure. Despite the modest sample size, exposure to blue LEDs has shown to affect sleep quality and median body temperature peak of these AD patients. Median body temperature peak was delayed by approximately 2 hours after exposure to blue LEDs compared to exposure to red LEDs and sleep quality was improved. This pilot study demonstrated that light, especially LEDs, can be an important contribution to helping AD patients regulate their circadian functions.

  4. Therapeutic applications of circadian rhythms for the cardiovascular system

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Frank A J L Scheer

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

  6. Circadian light

    Directory of Open Access Journals (Sweden)

    Bierman Andrew

    2010-02-01

    Full Text Available Abstract The present paper reflects a work in progress toward a definition of circadian light, one that should be informed by the thoughtful, century-old evolution of our present definition of light as a stimulus for the human visual system. This work in progress is based upon the functional relationship between optical radiation and its effects on nocturnal melatonin suppression, in large part because the basic data are available in the literature. Discussed here are the fundamental differences between responses by the visual and circadian systems to optical radiation. Brief reviews of photometry, colorimetry, and brightness perception are presented as a foundation for the discussion of circadian light. Finally, circadian light (CLA and circadian stimulus (CS calculation procedures based on a published mathematical model of human circadian phototransduction are presented with an example.

  7. Chronotherapeutic drug delivery systems: an approach to circadian rhythms diseases.

    Science.gov (United States)

    Sunil, S A; Srikanth, M V; Rao, N Sreenivasa; Uhumwangho, M U; Latha, K; Murthy, K V Ramana

    2011-11-01

    The purpose of writing this review on chronotherapeutic drug delivery systems (ChrDDs) is to review the literatures with special focus on ChrDDs and the various dosage forms, techniques that are used to target the circadian rhythms (CR) of various diseases. Many functions of the human body vary considerably in a day. ChrDDs refers to a treatment method in which in vivo drug availability is timed to match circadian rhythms of disease in order to optimize therapeutic outcomes and minimize side effects. Several techniques have been developed but not many dosage forms for all the diseases are available in the market. ChrDDs are gaining importance in the field of pharmaceutical technology as these systems reduce dosing frequency, toxicity and deliver the drug that matches the CR of that particular disease when the symptoms are maximum to worse. Finally, the ultimate benefit goes to the patient due the compliance and convenience of the dosage form. Some diseases that follow circadian rhythms include cardiovascular diseases, asthma, arthritis, ulcers, diabetes etc. ChrDDs in the market were also discussed and the current technologies used to formulate were also stated. These technologies include Contin® , Chronotopic®, Pulsincaps®, Ceform®, Timerx®, Oros®, Codas®, Diffucaps®, Egalet®, Tablet in capsule device, Core-in-cup tablet technology. A coated drug-core tablet matrix, A bi-layered tablet, Multiparticulate-based chronotherapeutic drug delivery systems, Chronoset and Controlled release microchips.

  8. Circadian-clock system in mouse liver affected by insulin resistance.

    Science.gov (United States)

    Yang, Shu-Chuan; Tseng, Huey-Lin; Shieh, Kun-Ruey

    2013-07-01

    Circadian rhythms are exhibited in the physiological and behavioral processes of all mammals; they are generated by intracellular levels of circadian oscillators, which are named as a set of circadian-clock genes. These genes compose the transcriptional/translational feedback loops to regulate not only circadian rhythmicity, but also energy metabolism. Previous studies have shown that obesity and diabetes cause the dysregulation of the circadian-clock system, and vice versa. However, some diabetes subjects are lean with insulin resistance and the mechanisms of insulin resistance without obesity are much less well known. Therefore, whether insulin resistance alone is enough to influence the expression of circadian-clock genes is uncertain. This study employs a neonatal streptozotocin (STZ)-treated paradigm in mice to model the molecular and physiological progress of nonobese insulin resistance. A single injection of STZ into 2-d-old male C57BL/6 mice induces nonobese, hyperglycemic and hyperinsulinemic conditions, and the levels of gene expression in the liver by a real-time quantitative polymerase chain reaction are then measured. Although the levels of Bmal1 (brain and muscle Arnt-like protein-1), Per2 (period 2), and Cry1 (cryptochrome 1) mRNA expression in the liver change during the progress of insulin resistance conditions, the gene expression patterns still show circadian rhythmicity. This study suggests that changes in the hepatic circadian-clock gene expression mark an early event in the metabolic disruption associated with insulin resistance. Furthermore, 2 wks of treatment with the thiazolidinedione, pioglitazone, fully resolve the dysfunction in metabolic parameters and the changes in circadian-clock gene expression from early insulin resistance conditions. These results indicate that the circadian-clock system is sensitive to insulin resistance, and that treatment with thiazolidinediones can resolve changes in the circadian-clock system in a timely

  9. Rhythmic Three-Part Harmony: The Complex Interaction of Maternal, Placental and Fetal Circadian Systems.

    Science.gov (United States)

    Mark, Peter J; Crew, Rachael C; Wharfe, Michaela D; Waddell, Brendan J

    2017-12-01

    From the perspective of circadian biology, mammalian pregnancy presents an unusual biological scenario in which an entire circadian system (i.e., that of the fetus) is embodied within another (i.e., that of the mother). Moreover, both systems are likely to be influenced at their interface by a third player, the placenta. Successful pregnancy requires major adaptations in maternal physiology, many of which involve circadian changes that support the high metabolic demands of the growing fetus. A functional role for maternal circadian adaptations is implied by the effects of circadian disruption, which result in pregnancy complications including higher risks for miscarriage, preterm labor, and low birth weight. Various aspects of fetal physiology lead to circadian variation, at least in late gestation, but it remains unclear what drives this rhythmicity. It likely involves contributions from the maternal environment and possibly from the placenta and the developing intrinsic molecular clocks within fetal tissues. The role of the placenta is of particular significance because it serves not only to relay signals about the external environment (via the mother) but may also exhibit its own circadian rhythmicity. This review considers how the fetus may be influenced by dynamic circadian signals from the mother and the placenta during gestation, and how, in the face of these changing influences, a new fetal circadian system emerges. Particular emphasis is placed on the role of endocrine signals, most notably melatonin and glucocorticoids, as mediators of maternal-fetal circadian interactions, and on the expression of the clock gene in the 3 compartments. Further study is required to understand how the mother, placenta, and fetus interact across pregnancy to optimize circadian adaptations that support adequate growth and development of the fetus and its transition to postnatal life in a circadian environment.

  10. Digital clocks: simple Boolean models can quantitatively describe circadian systems.

    Science.gov (United States)

    Akman, Ozgur E; Watterson, Steven; Parton, Andrew; Binns, Nigel; Millar, Andrew J; Ghazal, Peter

    2012-09-07

    The gene networks that comprise the circadian clock modulate biological function across a range of scales, from gene expression to performance and adaptive behaviour. The clock functions by generating endogenous rhythms that can be entrained to the external 24-h day-night cycle, enabling organisms to optimally time biochemical processes relative to dawn and dusk. In recent years, computational models based on differential equations have become useful tools for dissecting and quantifying the complex regulatory relationships underlying the clock's oscillatory dynamics. However, optimizing the large parameter sets characteristic of these models places intense demands on both computational and experimental resources, limiting the scope of in silico studies. Here, we develop an approach based on Boolean logic that dramatically reduces the parametrization, making the state and parameter spaces finite and tractable. We introduce efficient methods for fitting Boolean models to molecular data, successfully demonstrating their application to synthetic time courses generated by a number of established clock models, as well as experimental expression levels measured using luciferase imaging. Our results indicate that despite their relative simplicity, logic models can (i) simulate circadian oscillations with the correct, experimentally observed phase relationships among genes and (ii) flexibly entrain to light stimuli, reproducing the complex responses to variations in daylength generated by more detailed differential equation formulations. Our work also demonstrates that logic models have sufficient predictive power to identify optimal regulatory structures from experimental data. By presenting the first Boolean models of circadian circuits together with general techniques for their optimization, we hope to establish a new framework for the systematic modelling of more complex clocks, as well as other circuits with different qualitative dynamics. In particular, we anticipate

  11. Digital clocks: simple Boolean models can quantitatively describe circadian systems

    Science.gov (United States)

    Akman, Ozgur E.; Watterson, Steven; Parton, Andrew; Binns, Nigel; Millar, Andrew J.; Ghazal, Peter

    2012-01-01

    The gene networks that comprise the circadian clock modulate biological function across a range of scales, from gene expression to performance and adaptive behaviour. The clock functions by generating endogenous rhythms that can be entrained to the external 24-h day–night cycle, enabling organisms to optimally time biochemical processes relative to dawn and dusk. In recent years, computational models based on differential equations have become useful tools for dissecting and quantifying the complex regulatory relationships underlying the clock's oscillatory dynamics. However, optimizing the large parameter sets characteristic of these models places intense demands on both computational and experimental resources, limiting the scope of in silico studies. Here, we develop an approach based on Boolean logic that dramatically reduces the parametrization, making the state and parameter spaces finite and tractable. We introduce efficient methods for fitting Boolean models to molecular data, successfully demonstrating their application to synthetic time courses generated by a number of established clock models, as well as experimental expression levels measured using luciferase imaging. Our results indicate that despite their relative simplicity, logic models can (i) simulate circadian oscillations with the correct, experimentally observed phase relationships among genes and (ii) flexibly entrain to light stimuli, reproducing the complex responses to variations in daylength generated by more detailed differential equation formulations. Our work also demonstrates that logic models have sufficient predictive power to identify optimal regulatory structures from experimental data. By presenting the first Boolean models of circadian circuits together with general techniques for their optimization, we hope to establish a new framework for the systematic modelling of more complex clocks, as well as other circuits with different qualitative dynamics. In particular, we

  12. Nutrigenetics and Nutrimiromics of the Circadian System: The Time for Human Health

    Science.gov (United States)

    Micó, Víctor; Díez-Ricote, Laura; Daimiel, Lidia

    2016-01-01

    Even though the rhythmic oscillations of life have long been known, the precise molecular mechanisms of the biological clock are only recently being explored. Circadian rhythms are found in virtually all organisms and affect our lives. Thus, it is not surprising that the correct running of this clock is essential for cellular functions and health. The circadian system is composed of an intricate network of genes interwined in an intrincated transcriptional/translational feedback loop. The precise oscillation of this clock is controlled by the circadian genes that, in turn, regulate the circadian oscillations of many cellular pathways. Consequently, variations in these genes have been associated with human diseases and metabolic disorders. From a nutrigenetics point of view, some of these variations modify the individual response to the diet and interact with nutrients to modulate such response. This circadian feedback loop is also epigenetically modulated. Among the epigenetic mechanisms that control circadian rhythms, microRNAs are the least studied ones. In this paper, we review the variants of circadian-related genes associated to human disease and nutritional response and discuss the current knowledge about circadian microRNAs. Accumulated evidence on the genetics and epigenetics of the circadian system points to important implications of chronotherapy in the clinical practice, not only in terms of pharmacotherapy, but also for dietary interventions. However, interventional studies (especially nutritional trials) that include chronotherapy are scarce. Given the importance of chronobiology in human health such studies are warranted in the near future. PMID:26927084

  13. Plasticity of the intrinsic period of the human circadian timing system.

    Directory of Open Access Journals (Sweden)

    Frank A J L Scheer

    2007-08-01

    Full Text Available Human expeditions to Mars will require adaptation to the 24.65-h Martian solar day-night cycle (sol, which is outside the range of entrainment of the human circadian pacemaker under lighting intensities to which astronauts are typically exposed. Failure to entrain the circadian time-keeping system to the desired rest-activity cycle disturbs sleep and impairs cognitive function. Furthermore, differences between the intrinsic circadian period and Earth's 24-h light-dark cycle underlie human circadian rhythm sleep disorders, such as advanced sleep phase disorder and non-24-hour sleep-wake disorders. Therefore, first, we tested whether exposure to a model-based lighting regimen would entrain the human circadian pacemaker at a normal phase angle to the 24.65-h Martian sol and to the 23.5-h day length often required of astronauts during short duration space exploration. Second, we tested here whether such prior entrainment to non-24-h light-dark cycles would lead to subsequent modification of the intrinsic period of the human circadian timing system. Here we show that exposure to moderately bright light ( approximately 450 lux; approximately 1.2 W/m(2 for the second or first half of the scheduled wake episode is effective for entraining individuals to the 24.65-h Martian sol and a 23.5-h day length, respectively. Estimations of the circadian periods of plasma melatonin, plasma cortisol, and core body temperature rhythms collected under forced desynchrony protocols revealed that the intrinsic circadian period of the human circadian pacemaker was significantly longer following entrainment to the Martian sol as compared to following entrainment to the 23.5-h day. The latter finding of after-effects of entrainment reveals for the first time plasticity of the period of the human circadian timing system. Both findings have important implications for the treatment of circadian rhythm sleep disorders and human space exploration.

  14. Recent Advances in Circadian Rhythms in Cardiovascular System

    Directory of Open Access Journals (Sweden)

    Lihong eChen

    2015-04-01

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

  15. Evidence for a biological dawn and dusk in the human circadian timing system

    Science.gov (United States)

    Wehr, T A; Aeschbach, D; Duncan, W C

    2001-01-01

    Because individuals differ in the phase angle at which their circadian rhythms are entrained to external time cues, averaging group data relative to clock time sometimes obscures abrupt changes that are characteristic of waveforms of the rhythms in individuals. Such changes may have important implications for the temporal organization of human circadian physiology. To control for variance in phase angle of entrainment, we used dual internal reference points – onset and offset of the nocturnal period of melatonin secretion – to calculate average profiles of circadian rhythm data from five previously published studies. Onset and/or offset of melatonin secretion were found to coincide with switch-like transitions between distinct diurnal and nocturnal periods of circadian rhythms in core body temperature, sleepiness, power in the theta band of the wake EEG, sleep propensity and rapid eye movement (REM) sleep propensity. Transitions between diurnal and nocturnal periods of sleep–wake and cortisol circadian rhythms were found to lag the other transitions by 1–3 h. When the duration of the daily light period was manipulated experimentally, melatonin-onset-related transitions in circadian rhythms appeared to be entrained to the light-to-dark transition, while melatonin-offset-related transitions appeared to be entrained to the dark-to-light transition. These results suggest a model of the human circadian timing system in which two states, one diurnal and one nocturnal, alternate with one another, and in which transitions between the states are switch-like and are separately entrained to dawn and dusk. This description of the human circadian system is similar to the Pittendrigh–Daan model of the rodent circadian system, and it suggests that core features of the system in other mammals are conserved in humans. PMID:11559786

  16. [Melatonin as a regulator of human sleep and circadian systems].

    Science.gov (United States)

    Mishima, Kazuo

    2012-07-01

    Melatonin(N-acetyl-5-methoxytryptamine) is synthesized from tryptophan and is intensively secreted into the blood only in darkness (nighttime) by the pineal gland. Melatonin is not only the most reliable marker of internal circadian phase but also a potent sleep-promoting and circadian phase regulatory agent in humans. There is evidence that daytime administered melatonin is able to exhibit short-acting hypnagogic effect and phase-shifting of the circadian rhythms such that sleep timing and associated various physiological functions realign at a new desired phase. Under favor of these properties, melatonin and melatonin receptor agonists have been shown to be potent therapeutic agents for the treatment of circadian rhythm sleep disorders and some type of insomnia.

  17. Consequences of Circadian and Sleep Disturbances for the Cardiovascular System.

    Science.gov (United States)

    Alibhai, Faisal J; Tsimakouridze, Elena V; Reitz, Cristine J; Pyle, W Glen; Martino, Tami A

    2015-07-01

    Circadian rhythms play a crucial role in our cardiovascular system. Importantly, there has been a recent flurry of clinical and experimental studies revealing the profound adverse consequences of disturbing these rhythms on the cardiovascular system. For example, circadian disturbance worsens outcome after myocardial infarction with implications for patients in acute care settings. Moreover, disturbing rhythms exacerbates cardiac remodelling in heart disease models. Also, circadian dyssynchrony is a causal factor in the pathogenesis of heart disease. These discoveries have profound implications for the cardiovascular health of shift workers, individuals with circadian and sleep disorders, or anyone subjected to the 24/7 demands of society. Moreover, these studies give rise to 2 new frontiers for translational research: (1) circadian rhythms and the cardiac sarcomere, which sheds new light on our understanding of myofilament structure, signalling, and electrophysiology; and (2) knowledge translation, which includes biomarker discovery (chronobiomarkers), timing of therapies (chronotherapy), and other new promising approaches to improve the management and treatment of cardiovascular disease. Reconsidering circadian rhythms in the clinical setting benefits repair mechanisms, and offers new promise for patients. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  18. Redox regulation and pro-oxidant reactions in the physiology of circadian systems.

    Science.gov (United States)

    Méndez, Isabel; Vázquez-Martínez, Olivia; Hernández-Muñoz, Rolando; Valente-Godínez, Héctor; Díaz-Muñoz, Mauricio

    2016-05-01

    Rhythms of approximately 24 h are pervasive in most organisms and are known as circadian. There is a molecular circadian clock in each cell sustained by a feedback system of interconnected "clock" genes and transcription factors. In mammals, the timing system is formed by a central pacemaker, the suprachiasmatic nucleus, in coordination with a collection of peripheral oscillators. Recently, an extensive interconnection has been recognized between the molecular circadian clock and the set of biochemical pathways that underlie the bioenergetics of the cell. A principle regulator of metabolic networks is the flow of electrons between electron donors and acceptors. The concomitant reduction and oxidation (redox) reactions directly influence the balance between anabolic and catabolic processes. This review summarizes and discusses recent findings concerning the mutual and dynamic interactions between the molecular circadian clock, redox reactions, and redox signaling. The scope includes the regulatory role played by redox coenzymes (NAD(P)+/NAD(P)H, GSH/GSSG), reactive oxygen species (superoxide anion, hydrogen peroxide), antioxidants (melatonin), and physiological events that modulate the redox state (feeding condition, circadian rhythms) in determining the timing capacity of the molecular circadian clock. In addition, we discuss a purely metabolic circadian clock, which is based on the redox enzymes known as peroxiredoxins and is present in mammalian red blood cells and in other biological systems. Both the timing system and the metabolic network are key to a better understanding of widespread pathological conditions such as the metabolic syndrome, obesity, and diabetes. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  19. A multi-oscillatory circadian system times female reproduction

    Directory of Open Access Journals (Sweden)

    Valerie eSimonneaux

    2015-10-01

    Full Text Available Rhythms in female reproduction are critical to insure that timing of ovulation coincides with oocyte maturation and optimal sexual arousal. This fine tuning of female reproduction involves both the estradiol feedback as an indicator of oocyte maturation, and the master circadian clock of the suprachiasmatic nuclei as an indicator of the time of the day. Herein we are providing an overview of the state of knowledge regarding the differential inhibitory and stimulatory effects of estradiol at different stages of the reproductive axis, and the mechanisms through which the two main neurotransmitters of the suprachiasmatic nucleus, arginine vasopressin and vasoactive intestinal peptide, convey daily time cues to the reproductive axis. In addition we will report the most recent findings on the putative functions of peripheral clocks located throughout the reproductive axis (kisspeptin neurons, GnRH neurons, gonadotropic cells, the ovary and the uterus. This review will point to the critical position of the kisspeptin neurons of the anteroventral periventricular nucleus, which integrate both the stimulatory estradiol signal, and the daily arginine vasopressinergic signal, while displaying a circadian clock. Finally, given the critical role of the light/dark cycle in the synchronization of female reproduction, we will discuss the impact of circadian disruptions observed during shift work conditions on female reproductive performance and fertility in both animal model and humans.

  20. Peripheral circadian misalignment: contributor to systemic insulin resistance and potential intervention to improve bariatric surgical outcomes

    Science.gov (United States)

    Kunze, Kyle N.; Hanlon, Erin C.; Prachand, Vivek N.

    2016-01-01

    Thirteen percent of the world's population suffers from obesity and 39% from being overweight, which correlates with an increase in numerous secondary metabolic complications, such as Type 2 diabetes mellitus. Bariatric surgery is the most effective treatment for severe obesity and results in significant weight loss and the amelioration of obesity-related comorbidities through changes in enteroendocrine activity, caloric intake, and alterations in gut microbiota composition. The circadian system has recently been found to be a critical regulatory component in the control of metabolism and, thus, may potentially play an important role in inappropriate weight gain. Indeed, some behaviors and lifestyle factors associated with an increased risk of obesity are also risk factors for misalignment in the circadian clock system and for the metabolic syndrome. It is thus possible that alterations in peripheral circadian clocks in metabolically relevant tissues are a contributor to the current obesity epidemic. As such, it is plausible that postsurgical alterations in central circadian alignment, as well as peripheral gene expression in metabolic tissues may represent another mechanism for the beneficial effects of bariatric surgery. Bariatric surgery may represent an opportunity to identify changes in the circadian expression of clock genes that have been altered by environmental factors, allowing for a better understanding of the mechanism of action of surgery. These studies could also reveal an overlooked target for behavioral intervention to improve metabolic outcomes following bariatric surgery. PMID:27465735

  1. An evolutionary fitness enhancement conferred by the circadian system in cyanobacteria

    International Nuclear Information System (INIS)

    Ma, Peijun; Woelfle, Mark A.; Johnson, Carl Hirschie

    2013-01-01

    Circadian clocks are found in a wide variety of organisms from cyanobacteria to mammals. Many believe that the circadian clock system evolved as an adaption to the daily cycles in light and temperature driven by the rotation of the earth. Studies on the cyanobacterium, Synechococcus elongatus PCC 7942, have confirmed that the circadian clock in resonance with environmental cycles confers an adaptive advantage to cyanobacterial strains with different clock properties when grown in competition under light–dark cycles. The results thus far suggest that in a cyclic environment, the cyanobacterial strains whose free running periods are closest to the environmental period are the most fit and the strains lacking a functional circadian clock are at a competitive disadvantage relative to strains with a functional clock. In contrast, the circadian system provides little or no advantage to cyanobacteria grown in competition in constant light. To explain the potential mechanism of this clock-mediated enhancement in fitness in cyanobacteria, several models have been proposed; these include the limiting resource model, the diffusible inhibitor model and the cell-to-cell communication model. None of these models have been excluded by the currently available experimental data and the mechanistic basis of clock-mediated fitness enhancement remains elusive

  2. The Circadian Timing System: Making Sense of day/night gene expression

    Directory of Open Access Journals (Sweden)

    HANS G RICHTER

    2004-01-01

    Full Text Available The circadian time-keeping system ensures predictive adaptation of individuals to the reproducible 24-h day/night alternations of our planet by generating the 24-h (circadian rhythms found in hormone release and cardiovascular, biophysical and behavioral functions, and others. In mammals, the master clock resides in the suprachiasmatic nucleus (SCN of the hypothalamus. The molecular events determining the functional oscillation of the SCN neurons with a period of 24-h involve recurrent expression of several clock proteins that interact in complex transcription/translation feedback loops. In mammals, a glutamatergic monosynaptic pathway originating from the retina regulates the clock gene expression pattern in the SCN neurons, synchronizing them to the light:dark cycle. The emerging concept is that neural/humoral output signals from the SCN impinge upon peripheral clocks located in other areas of the brain, heart, lung, gastrointestinal tract, liver, kidney, fibroblasts, and most of the cell phenotypes, resulting in overt circadian rhythms in integrated physiological functions. Here we review the impact of day/night alternation on integrated physiology; the molecular mechanisms and input/output signaling pathways involved in SCN circadian function; the current concept of peripheral clocks; and the potential role of melatonin as a circadian neuroendocrine transducer

  3. Circadian control of dendrite morphology in the visual system of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Paweł Weber

    Full Text Available In the first optic neuropil (lamina of the fly's visual system, monopolar cells L1 and L2 and glia show circadian rhythms in morphological plasticity. They change their size and shape during the day and night. The most pronounced changes have been detected in circadian size of the L2 axons. Looking for a functional significance of the circadian plasticity observed in axons, we examined the morphological plasticity of the L2 dendrites. They extend from axons and harbor postsynaptic sites of tetrad synaptic contacts from the photoreceptor terminals.The plasticity of L2 dendrites was evaluated by measuring an outline of the L2 dendritic trees. These were from confocal images of cross sections of L2 cells labeled with GFP. They were in wild-type and clock mutant flies held under different light conditions and sacrified at different time points. We found that the L2 dendrites are longest at the beginning of the day in both males and females. This rhythm observed under a day/night regime (LD was maintained in constant darkness (DD but not in continuous light (LL. This rhythm was not present in the arrhythmic per(01 mutant in LD or in DD. In the clock photoreceptor cry(b mutant the rhythm was maintained but its pattern was different than that observed in wild-type flies.The results obtained showed that the L2 dendrites exhibit circadian structural plasticity. Their morphology is controlled by the per gene-dependent circadian clock. The L2 dendrites are longest at the beginning of the day when the daytime tetrad presynaptic sites are most numerous and L2 axons are swollen. The presence of the rhythm, but with a different pattern in cry(b mutants in LD and DD indicates a new role of cry in the visual system. The new role is in maintaining the circadian pattern of changes of the L2 dendrite length and shape.

  4. Circadian rhythms in systemic hemodynamics and renal function in healthy subjects and patients with nephrotic syndrome

    NARCIS (Netherlands)

    Voogel, A. J.; Koopman, M. G.; Hart, A. A.; van Montfrans, G. A.; Arisz, L.

    2001-01-01

    The resemblance of the circadian rhythm of glomerular filtration rate (GFR) to that of arterial blood pressure (BP) suggests that systemic hemodynamic factors contribute to this variation. In the present study, this was investigated using continuous BP monitoring and pulse wave analysis. The study

  5. Circadian System and Melatonin Hormone: Risk Factors for Complications during Pregnancy

    Directory of Open Access Journals (Sweden)

    F. J. Valenzuela

    2015-01-01

    Full Text Available Pregnancy is a complex and well-regulated temporal event in which several steps are finely orchestrated including implantation, decidualization, placentation, and partum and any temporary alteration has serious effects on fetal and maternal health. Interestingly, alterations of circadian rhythms (i.e., shiftwork have been correlated with increased risk of preterm delivery, intrauterine growth restriction, and preeclampsia. In the last few years evidence is accumulating that the placenta may have a functional circadian system and express the clock genes Bmal1, Per1-2, and Clock. On the other hand, there is evidence that the human placenta synthesizes melatonin, hormone involved in the regulation of the circadian system in other tissues. Moreover, is unknown the role of this local production of melatonin and whether this production have a circadian pattern. Available information indicates that melatonin induces in placenta the expression of antioxidant enzymes catalase and superoxide dismutase, prevents the injury produced by oxidative stress, and inhibits the expression of vascular endothelial growth factor (VEGF a gene that in other tissues is controlled by clock genes. In this review we aim to analyze available information regarding clock genes and clock genes controlled genes such as VEGF and the possible role of melatonin synthesis in the placenta.

  6. Relationships between the circadian system and Alzheimer's disease-like symptoms in Drosophila.

    Directory of Open Access Journals (Sweden)

    Dani M Long

    Full Text Available Circadian clocks coordinate physiological, neurological, and behavioral functions into circa 24 hour rhythms, and the molecular mechanisms underlying circadian clock oscillations are conserved from Drosophila to humans. Clock oscillations and clock-controlled rhythms are known to dampen during aging; additionally, genetic or environmental clock disruption leads to accelerated aging and increased susceptibility to age-related pathologies. Neurodegenerative diseases, such as Alzheimer's disease (AD, are associated with a decay of circadian rhythms, but it is not clear whether circadian disruption accelerates neuronal and motor decline associated with these diseases. To address this question, we utilized transgenic Drosophila expressing various Amyloid-β (Aβ peptides, which are prone to form aggregates characteristic of AD pathology in humans. We compared development of AD-like symptoms in adult flies expressing Aβ peptides in the wild type background and in flies with clocks disrupted via a null mutation in the clock gene period (per01. No significant differences were observed in longevity, climbing ability and brain neurodegeneration levels between control and clock-deficient flies, suggesting that loss of clock function does not exacerbate pathogenicity caused by human-derived Aβ peptides in flies. However, AD-like pathologies affected the circadian system in aging flies. We report that rest/activity rhythms were impaired in an age-dependent manner. Flies expressing the highly pathogenic arctic Aβ peptide showed a dramatic degradation of these rhythms in tune with their reduced longevity and impaired climbing ability. At the same time, the central pacemaker remained intact in these flies providing evidence that expression of Aβ peptides causes rhythm degradation downstream from the central clock mechanism.

  7. Individual recognition of social rank and social memory performance depends on a functional circadian system.

    Science.gov (United States)

    Müller, L; Weinert, D

    2016-11-01

    In a natural environment, social abilities of an animal are important for its survival. Particularly, it must recognize its own social rank and the social rank of a conspecific and have a good social memory. While the role of the circadian system for object and spatial recognition and memory is well known, the impact of the social rank and circadian disruptions on social recognition and memory were not investigated so far. In the present study, individual recognition of social rank and social memory performance of Djungarian hamsters revealing different circadian phenotypes were investigated. Wild type (WT) animals show a clear and well-synchronized daily activity rhythm, whereas in arrhythmic (AR) hamsters, the suprachiasmatic nuclei (SCN) do not generate a circadian signal. The aim of the study was to investigate putative consequences of these deteriorations in the circadian system for animalś cognitive abilities. Hamsters were bred and kept under standardized housing conditions with food and water ad libitum and a 14l/10 D lighting regimen. Experimental animals were assigned to different groups (WT and AR) according to their activity pattern obtained by means of infrared motion sensors. Before the experiments, the animals were given to develop a dominant-subordinate relationship in a dyadic encounter. Experiment 1 dealt with individual recognition of social rank. Subordinate and dominant hamsters were tested in an open arena for their behavioral responses towards a familiar (known from the agonistic encounters) or an unfamiliar hamster (from another agonistic encounter) which had the same or an opposite social rank. The investigation time depended on the social rank of the WT subject hamster and its familiarity with the stimulus animal. Both subordinate and dominant WT hamsters preferred an unfamiliar subordinate stimulus animal. In contrast, neither subordinate nor dominant AR hamsters preferred any of the stimulus animals. Thus, disruptions in circadian

  8. Sustainable System for Residual Hazards Management

    International Nuclear Information System (INIS)

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour

    2004-01-01

    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today's waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous long-term management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by external intrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the long-term success of the prescribed system. In fact

  9. Preliminary evidence for a change in spectral sensitivity of the circadian system at night

    Directory of Open Access Journals (Sweden)

    Parsons Robert H

    2005-12-01

    Full Text Available Abstract Background It is well established that the absolute sensitivity of the suprachiasmatic nucleus to photic stimulation received through the retino-hypothalamic tract changes throughout the 24-hour day. It is also believed that a combination of classical photoreceptors (rods and cones and melanopsin-containing retinal ganglion cells participate in circadian phototransduction, with a spectral sensitivity peaking between 440 and 500 nm. It is still unknown, however, whether the spectral sensitivity of the circadian system also changes throughout the solar day. Reported here is a new study that was designed to determine whether the spectral sensitivity of the circadian retinal phototransduction mechanism, measured through melatonin suppression and iris constriction, varies at night. Methods Human adult males were exposed to a high-pressure mercury lamp [450 lux (170 μW/cm2 at the cornea] and an array of blue light emitting diodes [18 lux (29 μW/cm2 at the cornea] during two nighttime experimental sessions. Both melatonin suppression and iris constriction were measured during and after a one-hour light exposure just after midnight and just before dawn. Results An increase in the percentage of melatonin suppression and an increase in pupil constriction for the mercury source relative to the blue light source at night were found, suggesting a temporal change in the contribution of photoreceptor mechanisms leading to melatonin suppression and, possibly, iris constriction by light in humans. Conclusion The preliminary data presented here suggest a change in the spectral sensitivity of circadian phototransduction mechanisms at two different times of the night. These findings are hypothesized to be the result of a change in the sensitivity of the melanopsin-expressing retinal ganglion cells to light during the night.

  10. A circadian clock in Antarctic krill: an endogenous timing system governs metabolic output rhythms in the euphausid species Euphausia superba.

    Directory of Open Access Journals (Sweden)

    Mathias Teschke

    Full Text Available Antarctic krill, Euphausia superba, shapes the structure of the Southern Ocean ecosystem. Its central position in the food web, the ongoing environmental changes due to climatic warming, and increasing commercial interest on this species emphasize the urgency of understanding the adaptability of krill to its environment. Krill has evolved rhythmic physiological and behavioral functions which are synchronized with the daily and seasonal cycles of the complex Southern Ocean ecosystem. The mechanisms, however, leading to these rhythms are essentially unknown. Here, we show that krill possesses an endogenous circadian clock that governs metabolic and physiological output rhythms. We found that expression of the canonical clock gene cry2 was highly rhythmic both in a light-dark cycle and in constant darkness. We detected a remarkable short circadian period, which we interpret as a special feature of the krill's circadian clock that helps to entrain the circadian system to the extreme range of photoperiods krill is exposed to throughout the year. Furthermore, we found that important key metabolic enzymes of krill showed bimodal circadian oscillations (∼9-12 h period in transcript abundance and enzymatic activity. Oxygen consumption of krill showed ∼9-12 h oscillations that correlated with the temporal activity profile of key enzymes of aerobic energy metabolism. Our results demonstrate the first report of an endogenous circadian timing system in Antarctic krill and its likely link to metabolic key processes. Krill's circadian clock may not only be critical for synchronization to the solar day but also for the control of seasonal events. This study provides a powerful basis for the investigation into the mechanisms of temporal synchronization in this marine key species and will also lead to the first comprehensive analyses of the circadian clock of a polar marine organism through the entire photoperiodic cycle.

  11. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    significance. (right) Vijay Kumar Sharma is a Professor at the. Evolutionary and. Organismal Biology Unit,. JNCASR, Bangalore. His major research interests presently are in understand- ing circadian organization of fruit flies and ants, adaptive significance of circadian clocks, neurogenetics of circadian egg-laying rhythm.

  12. Glia-related circadian plasticity in the visual system of Diptera

    Directory of Open Access Journals (Sweden)

    Jolanta eGórska-Andrzejak

    2013-08-01

    Full Text Available The circadian changes in morphology of the first visual neuropil or lamina of Diptera represents an example of the neuronal plasticity controlled by the circadian clock (circadian plasticity. It is observed in terminals of the compound eye photoreceptor cells, the peripheral oscillators expressing the clock genes. However, it has been found also in their postsynaptic partners, the L1 and L2 monopolar cells, in which the activity of the clock genes have not yet been detected. The circadian input that the L1 and L2 receive seems to originate not only from the retina photoreceptors and from the circadian pacemaker neurons located in the brain, but also from the glial cells that express the clock genes and thus contain circadian oscillators. This paper summarizes the morphological and biochemical rhythms in glia of the optic lobe, shows how they contribute to circadian plasticity, and discusses how glial clocks may modulate circadian rhythms in the lamina.

  13. The mPer2 clock gene modulates cocaine actions in the mouse circadian system.

    Science.gov (United States)

    Brager, Allison J; Stowie, Adam C; Prosser, Rebecca A; Glass, J David

    2013-04-15

    Cocaine is a potent disruptor of photic and non-photic pathways for circadian entrainment of the master circadian clock of the suprachiasmatic nucleus (SCN). These actions of cocaine likely involve its modulation of molecular (clock gene) components for SCN clock timekeeping. At present, however, the physiological basis of such an interaction is unclear. To address this question, we compared photic and non-photic phase-resetting responses between wild-type (WT) and Per2 mutant mice expressing nonfunctional PER2 protein to systemic and intra-SCN cocaine administrations. In the systemic trials, cocaine was administered i.p. (20 mg/kg) either at midday or prior to a light pulse in the early night to assess its non-photic and photic behavioral phase-resetting actions, respectively. In the intra-SCN trial, cocaine was administered by reverse microdialysis at midday to determine if the SCN is a direct target for its non-photic phase-resetting action. Non-photic phase-advancing responses to i.p. cocaine at midday were significantly (∼3.5-fold) greater in Per2 mutants than WTs. However, the phase-advancing action of intra-SCN cocaine perfusion at midday did not differ between genotypes. In the light pulse trial, Per2 mutants exhibited larger photic phase-delays than did WTs, and the attenuating action of cocaine on this response was proportionately larger than in WTs. These data indicate that the Per2 clock gene is a potent modulator of cocaine's actions in the circadian system. With regard to non-photic phase-resetting, the SCN is confirmed as a direct target of cocaine action; however, Per2 modulation of this effect likely occurs outside of the SCN. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

    Science.gov (United States)

    Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

    2016-08-01

    In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this

  15. Evidences of Polymorphism Associated with Circadian System and Risk of Pathologies: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    F. J. Valenzuela

    2016-01-01

    Full Text Available The circadian system is a supraphysiological system that modulates different biological functions such as metabolism, sleep-wake, cellular proliferation, and body temperature. Different chronodisruptors have been identified, such as shift work, feeding time, long days, and stress. The environmental changes and our modern lifestyle can alter the circadian system and increase the risk of developing pathologies such as cancer, preeclampsia, diabetes, and mood disorder. This system is organized by transcriptional/tranductional feedback loops of clock genes Clock, Bmal1, Per1–3, and Cry1-2. How molecular components of the clock are able to influence the development of diseases and their risk relation with genetic components of polymorphism of clock genes is unknown. This research describes different genetic variations in the population and how these are associated with risk of cancer, metabolic diseases such as diabetes, obesity, and dyslipidemias, and also mood disorders such as depression, bipolar disease, excessive alcohol intake, and infertility. Finally, these findings will need to be implemented and evaluated at the level of genetic interaction and how the environment factors trigger the expression of these pathologies will be examined.

  16. Circadian Patterns of Rats in Their Home Cages Detected Using a Video Tracking System.

    Science.gov (United States)

    Shieh, Kun-Ruey; Chen, Rong-Jie; Yang, Shu-Chuan

    2017-12-31

    The diurnal rhythm is the common event in nature and specially shows in the behavioral patterns. Using the infrared sensor or photo beam detector to detect this 24-h rhythmicity in behaviors of mammalian, including in the rats and mice, is also the common way. The photo-sensory detecting mean is friendly and its advantage is unrestricted by light density and light-dark transition. However, this kind of equipment is cost-expensive and uneasy to fit for home cage in rodents. In this study, we tried to use the video-tracking system to detect the rhythmic activity of rats in their home cages. Adult male Sprague-Dawley rats, weighing 250-280 g, were used in this study and individual was kept in its own cage. Combined with the infrared sensitive charge-coupled device (CCD) camera and with automatically lights-off sensitive infrared illuminants as the accessory device, we found that animals exhibited the circadian locomotor activity in either light-dark cycles or constant darkness conditions. Moreover, the rhythmic patterns of locomotion in animals were affected by the one-hour exposure of white light under the constant darkness condition. The phase-advanced effects were found by the video tracking system. In summary, the video tracking system is the useful way to detect the rhythmic activity, especially in long-term circadian rhythmicity, in rats.

  17. Influence of Electric, Magnetic, and Electromagnetic Fields on the Circadian System: Current Stage of Knowledge

    Science.gov (United States)

    Żak, Arkadiusz

    2014-01-01

    One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms—two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields. PMID:25136557

  18. Influence of electric, magnetic, and electromagnetic fields on the circadian system: current stage of knowledge.

    Science.gov (United States)

    Lewczuk, Bogdan; Redlarski, Grzegorz; Zak, Arkadiusz; Ziółkowska, Natalia; Przybylska-Gornowicz, Barbara; Krawczuk, Marek

    2014-01-01

    One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms-two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields.

  19. Influence of Electric, Magnetic, and Electromagnetic Fields on the Circadian System: Current Stage of Knowledge

    Directory of Open Access Journals (Sweden)

    Bogdan Lewczuk

    2014-01-01

    Full Text Available One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms—two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields.

  20. Residue number systems theory and applications

    CERN Document Server

    Mohan, P V Ananda

    2016-01-01

    This new and expanded monograph improves upon Mohan's earlier book, Residue Number Systems (Springer, 2002) with a state of the art treatment of the subject. Replete with detailed illustrations and helpful examples, this book covers a host of cutting edge topics such as the core function, the quotient function, new Chinese Remainder theorems, and large integer operations. It also features many significant applications to practical communication systems and cryptography such as FIR filters and elliptic curve cryptography. Starting with a comprehensive introduction to the basics and leading up to current research trends that are not yet widely distributed in other publications, this book will be of interest to both researchers and students alike.

  1. CAREM-25: Residual heat removal system

    International Nuclear Information System (INIS)

    Arvia, Roberto P.; Coppari, Norberto R.; Gomez de Soler, Susana M.; Ramilo, Lucia B.

    2000-01-01

    The objective of this work was the definition and consolidation of the residual heat removal system for the CAREM 25 reactor. The function of this system is cool down the primary circuit, removing the core decay heat from hot stand-by to cold shutdown and during refueling. In addition, this system heats the primary water from the cold shutdown condition to hot stand-by condition during the reactor start up previous to criticality. The system has been designed according to the requirements of the standards: ANSI/ANS 51.1 'Nuclear safety criteria for the design of stationary PWR plants'; ANSI/ANS 58.11 'Design criteria for safe shutdown following selected design basis events in light water reactors' and ANSI/ANS 58.9 'Single failure criteria for light water reactor safety-related fluid systems'. The suggested design fulfills the required functions and design criteria standards. (author)

  2. A personalised and adaptive intelligent system to adjust circadian lighting for elderly housing

    DEFF Research Database (Denmark)

    Flyvholm, Anton; Sen, Sumit; Xylakis, Emmanouil

    2016-01-01

    With the rapid population ageing in Europe and in Denmark, there is an increasing interest in technologies and designs that can support the elderly citizens in sustaining well-being and health along with preventing functional decline [1]. To date, the designs of lighting systems in elderly housing...... the development of a personalised and adaptive intelligent system [4] to adjust the lighting design in order to improve well-being and comfort levels, as well as to meet the needs of elderly people at home. To this goal, circadian adjusted LED-based (CaLED) lighting is used, which can reflect the rhythm of out......-door daylight. CaLED lighting seems that may positively influence age-related needs, mood, cognition, alertness, sleep and improve well-being in general [5][6]. To build this intelligent system 3 different types of data are considered and cross-checked: a) medical (biofactors), b) sensor-based (activity...

  3. A train of blue light pulses delivered through closed eyelids suppresses melatonin and phase shifts the human circadian system

    Directory of Open Access Journals (Sweden)

    Figueiro MG

    2013-10-01

    Full Text Available Mariana G Figueiro, Andrew Bierman, Mark S ReaLighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, USAAbstract: A model of circadian phototransduction was published in 2005 to predict the spectral sensitivity of the human circadian system to narrow-band and polychromatic light sources by combining responses to light from the spectral-opponent “blue” versus “yellow” cone bipolar pathway with direct responses to light by the intrinsically photosensitive retinal ganglion cells. In the model, depolarizing “blue” responses, but not hyperpolarizing “yellow” responses, from the “blue” versus “yellow” pathway are combined with the intrinsically photosensitive retinal ganglion cell responses. Intrinsically photosensitive retinal ganglion cell neurons are known to be much slower to respond to light than the cone pathway, so an implication of the model is that periodic flashes of “blue” light, but not “yellow” light, would be effective for stimulating the circadian system. A within-subjects study was designed to test the implications of the model regarding retinal exposures to brief flashes of light. The study was also aimed at broadening the foundation for clinical treatment of circadian sleep disorders by delivering flashing light through closed eyelids while people were asleep. In addition to a dark control night, the eyelids of 16 subjects were exposed to three light-stimulus conditions in the phase delay portion of the phase response curve while they were asleep: (1 2-second flashes of 111 W/m2 of blue (λmax ≈ 480 nm light once every minute for 1 hour, (2 131 W/m2 of green (λmax ≈ 527 nm light, continuously on for 1 hour, and (3 2-second flashes of the same green light once every minute for 1 hour. Inferential statistics showed that the blue flash light-stimulus condition significantly delayed circadian phase and significantly suppressed nocturnal melatonin. The results of this study further our

  4. 76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

    Science.gov (United States)

    2011-03-24

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc.), Collectible Concepts Group, Inc., Communitronics of... is a lack of current and accurate information concerning the securities of Clean Energy Combustion...

  5. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 7. Circadian Rhythms - From Daily Rhythms to Biological Clocks. Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 7 July 2013 pp 662- ... Keywords. Circadian rhythms; biological clocks; geophysical cycles; entrainment.

  6. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    hunger and sleep at the same time as the body would not be in the right state to metabolise food efficiently. Thus, synchronization of internal rhythms is an essential aspect of physiology, and circadian rhythms benefit living beings by bringing about such temporal order. In other words, circadian rhythms are thought to.

  7. Circadian dysregulation in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Aleksandar Videnovic

    2017-01-01

    Full Text Available Parkinson's disease (PD is the second most common neurodegenerative disorder that affects over one million individuals in the US alone. PD is characterized by a plethora of motor and non-motor manifestations, resulting from a progressive degeneration of dopaminergic neurons and disbalance of several other neurotransmitters. A growing body of evidence points to significant alterations of the circadian system in PD. This is not surprising given the pivotal role that dopamine plays in circadian regulation as well as the role of circadian influences in dopamine metabolism. In this review we present basic and clinical investigations that examined the function of the circadian system in PD.

  8. Residual energy applications program systems analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Yngve, P.W.

    1980-10-01

    Current DOE plans call for building an Energy Applied Systems Test (EAST) Facility at the Savannah River Plant in close proximity to the 140 to 150/sup 0/F waste heat from one of several operating nuclear reactors. The waste water flow from each reactor, approximately 165,000 gpm, provides a unique opportunity to test the performance and operating characteristics of large-scale waste heat power generation and heat pump system concepts. This report provides a preliminary description of the potential end-use market, parametric data on heat pump and the power generation system technology, a preliminary listing of EAST Facility requirements, and an example of an integrated industrial park utilizing the technology to maximize economic pay back. The parametric heat pump analysis concluded that dual-fluid Rankine cycle heat pumps with capacities as high as 400 x 10/sup 6/ Btu/h, can utilize large sources of low temperature residual heat to provide 300/sup 0/F saturatd steam for an industrial park. The before tax return on investment for this concept is 36.2%. The analysis also concluded that smaller modular heat pumps could fulfill the same objective while sacrificing only a moderate rate of return. The parametric power generation analysis concluded that multi-pressure Rankine cycle systems not only are superior to single pressure systems, but can also be developed for large systems (approx. = 17 MW/sub e/). This same technology is applicable to smaller systems at the sacrifice of higher investment per unit output.

  9. The Circadian System : A Regulatory Feedback Network of Periphery and Brain

    NARCIS (Netherlands)

    Buijs, Frederik N; León-Mercado, Luis; Guzmán-Ruiz, Mara; Guerrero-Vargas, Natali N; Romo-Nava, Francisco; Buijs, Ruud M

    Circadian rhythms are generated by the autonomous circadian clock, the suprachiasmatic nucleus (SCN), and clock genes that are present in all tissues. The SCN times these peripheral clocks, as well as behavioral and physiological processes. Recent studies show that frequent violations of conditions

  10. System-driven and oscillator-dependent circadian transcription in mice with a conditionally active liver clock.

    Directory of Open Access Journals (Sweden)

    Benoît Kornmann

    2007-02-01

    Full Text Available The mammalian circadian timing system consists of a master pacemaker in neurons of the suprachiasmatic nucleus (SCN and clocks of a similar molecular makeup in most peripheral body cells. Peripheral oscillators are self-sustained and cell autonomous, but they have to be synchronized by the SCN to ensure phase coherence within the organism. In principle, the rhythmic expression of genes in peripheral organs could thus be driven not only by local oscillators, but also by circadian systemic signals. To discriminate between these mechanisms, we engineered a mouse strain with a conditionally active liver clock, in which REV-ERBalpha represses the transcription of the essential core clock gene Bmal1 in a doxycycline-dependent manner. We examined circadian liver gene expression genome-wide in mice in which hepatocyte oscillators were either running or arrested, and found that the rhythmic transcription of most genes depended on functional hepatocyte clocks. However, we discovered 31 genes, including the core clock gene mPer2, whose expression oscillated robustly irrespective of whether the liver clock was running or not. By contrast, in liver explants cultured in vitro, circadian cycles of mPer2::luciferase bioluminescence could only be observed when hepatocyte oscillators were operational. Hence, the circadian cycles observed in the liver of intact animals without functional hepatocyte oscillators were likely generated by systemic signals. The finding that rhythmic mPer2 expression can be driven by both systemic cues and local oscillators suggests a plausible mechanism for the phase entrainment of subsidiary clocks in peripheral organs.

  11. Mathematical modeling of the circadian rhythm of key neuroendocrine-immune system players in rheumatoid arthritis: a systems biology approach.

    Science.gov (United States)

    Meyer-Hermann, Michael; Figge, Marc Thilo; Straub, Rainer H

    2009-09-01

    Healthy subjects and patients with rheumatoid arthritis (RA) exhibit circadian rhythms of the neuroendocrine-immune system. Understanding circadian dynamics is complex due to the nonlinear behavior of the neuroendocrine-immune network. This study was undertaken to seek and test a mathematical model for studying this network. We established a quantitative computational model to simulate nonlinear interactions between key factors in the neuroendocrine-immune system, such as plasma tumor necrosis factor (TNF), plasma cortisol (and adrenal cholesterol store), and plasma noradrenaline (NA) (and presynaptic NA store). The model was nicely fitted with measured reference data on healthy subjects and RA patients. Although the individual circadian pacemakers of cortisol, NA, and TNF were installed without a phase shift, the relative phase shift between these factors evolved as a consequence of the modeled network interactions. Combined long-term and short-term TNF increase (the "RA model") increased cortisol plasma levels for only a few days, and cholesterol stores started to become markedly depleted. This nicely demonstrated the phenomenon of inadequate cortisol secretion relative to plasma TNF levels, as a consequence of adrenal deficiency. Using the RA model, treatment with glucocorticoids between midnight and 2:00 AM was found to have the strongest inhibitory effect on TNF secretion, which supports recent studies on RA therapy. Long-term reduction of TNF levels by simulation of anti-TNF therapy normalized cholesterol stores under "RA" conditions. These first in silico studies of the neuroendocrine-immune system in rheumatology demonstrate that computational biology in medicine, making use of large collections of experimental data, supports understanding of the pathophysiology of complex nonlinear systems.

  12. Clock-dependent and system-driven oscillators interact in the suprachiasmatic nuclei to pace mammalian circadian rhythms.

    Directory of Open Access Journals (Sweden)

    Karine Abitbol

    Full Text Available Circadian clocks drive biological rhythms with a period of approximately 24 hours and keep in time with the outside world through daily resetting by environmental cues. While this external entrainment has been extensively investigated in the suprachiasmatic nuclei (SCN, the role of internal systemic rhythms, including daily fluctuations in core temperature or circulating hormones remains debated. Here, we show that lactating mice, which exhibit dampened systemic rhythms, possess normal molecular clockwork but impaired rhythms in both heat shock response gene expression and electrophysiological output in their SCN. This suggests that body rhythms regulate SCN activity downstream of the clock. Mathematical modeling predicts that systemic feedback upon the SCN functions as an internal oscillator that accounts for in vivo and ex vivo observations. Thus we are able to propose a new bottom-up hierarchical organization of circadian timekeeping in mammals, based on the interaction in the SCN between clock-dependent and system-driven oscillators.

  13. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2 ... Adaptation; fitness; circadian resonance; latitudinal clines; experimental evolution. ... Chronobiology Laboratory Evolutionary and Organismal Biology Unit Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, PO Box 6436, ...

  14. Impact of heart-specific disruption of the circadian clock on systemic glucose metabolism in mice.

    Science.gov (United States)

    Nakao, Tomomi; Kohsaka, Akira; Otsuka, Tsuyoshi; Thein, Zaw Lin; Le, Hue Thi; Waki, Hidefumi; Gouraud, Sabine S; Ihara, Hayato; Nakanishi, Masako; Sato, Fuyuki; Muragaki, Yasuteru; Maeda, Masanobu

    2017-12-22

    The daily rhythm of glucose metabolism is governed by the circadian clock, which consists of cell-autonomous clock machineries residing in nearly every tissue in the body. Disruption of these clock machineries either environmentally or genetically induces the dysregulation of glucose metabolism. Although the roles of clock machineries in the regulation of glucose metabolism have been uncovered in major metabolic tissues, such as the pancreas, liver, and skeletal muscle, it remains unknown whether clock function in non-major metabolic tissues also affects systemic glucose metabolism. Here, we tested the hypothesis that disruption of the clock machinery in the heart might also affect systemic glucose metabolism, because heart function is known to be associated with glucose tolerance. We examined glucose and insulin tolerance as well as heart phenotypes in mice with heart-specific deletion of Bmal1, a core clock gene. Bmal1 deletion in the heart not only decreased heart function but also led to systemic insulin resistance. Moreover, hyperglycemia was induced with age. Furthermore, heart-specific Bmal1-deficient mice exhibited decreased insulin-induced phosphorylation of Akt in the liver, thus indicating that Bmal1 deletion in the heart causes hepatic insulin resistance. Our findings revealed an unexpected effect of the function of clock machinery in a non-major metabolic tissue, the heart, on systemic glucose metabolism in mammals.

  15. Interdependence of nutrient metabolism and the circadian clock system: Importance for metabolic health

    Science.gov (United States)

    Ribas-Latre, Aleix; Eckel-Mahan, Kristin

    2016-01-01

    Background While additional research is needed, a number of large epidemiological studies show an association between circadian disruption and metabolic disorders. Specifically, obesity, insulin resistance, cardiovascular disease, and other signs of metabolic syndrome all have been linked to circadian disruption in humans. Studies in other species support this association and generally reveal that feeding that is not in phase with the external light/dark cycle, as often occurs with night or rotating shift workers, is disadvantageous in terms of energy balance. As food is a strong driver of circadian rhythms in the periphery, understanding how nutrient metabolism drives clocks across the body is important for dissecting out why circadian misalignment may produce such metabolic effects. A number of circadian clock proteins as well as their accessory proteins (such as nuclear receptors) are highly sensitive to nutrient metabolism. Macronutrients and micronutrients can function as zeitgebers for the clock in a tissue-specific way and can thus impair synchrony between clocks across the body, or potentially restore synchrony in the case of circadian misalignment. Circadian nuclear receptors are particularly sensitive to nutrient metabolism and can alter tissue-specific rhythms in response to changes in the diet. Finally, SNPs in human clock genes appear to be correlated with diet-specific responses and along with chronotype eventually may provide valuable information from a clinical perspective on how to use diet and nutrition to treat metabolic disorders. Scope of review This article presents a background of the circadian clock components and their interrelated metabolic and transcriptional feedback loops, followed by a review of some recent studies in humans and rodents that address the effects of nutrient metabolism on the circadian clock and vice versa. We focus on studies in which results suggest that nutrients provide an opportunity to restore or, alternatively

  16. The Circadian System: A Regulatory Feedback Network of Periphery and Brain

    OpenAIRE

    Buijs, Frederik N; León-Mercado, Luis; Guzmán-Ruiz, Mara; Guerrero-Vargas, Natali N; Romo-Nava, Francisco; Buijs, Ruud M

    2016-01-01

    Circadian rhythms are generated by the autonomous circadian clock, the suprachiasmatic nucleus (SCN), and clock genes that are present in all tissues. The SCN times these peripheral clocks, as well as behavioral and physiological processes. Recent studies show that frequent violations of conditions set by our biological clock, such as shift work, jet lag, sleep deprivation, or simply eating at the wrong time of the day, may have deleterious effects on health. This infringement, also known as ...

  17. The circadian system is a target and modulator of prenatal cocaine effects.

    Directory of Open Access Journals (Sweden)

    Eva H Shang

    2007-07-01

    Full Text Available Prenatal exposure to cocaine can be deleterious to embryonic brain development, but the results in humans remain controversial, the mechanisms involved are not well understood and effective therapies are yet to be designed. We hypothesize that some of the prenatal effects of cocaine might be related to dysregulation of physiological rhythms due to alterations in the integrating circadian clock function.Here we introduce a new high-throughput genetically well-characterized diurnal vertebrate model for studying the mechanisms of prenatal cocaine effects by demonstrating reduced viability and alterations in the pattern of neuronal development following repeated cocaine exposure in zebrafish embryos. This effect is associated with acute cocaine-induced changes in the expression of genes affecting growth (growth hormone, zGH and neurotransmission (dopamine transporter, zDAT. Analysis of circadian gene expression, using quantitative real-time RT-PCR (QPCR, demonstrates that cocaine acutely and dose-dependently changes the expression of the circadian genes (zPer-3, zBmal-1 and genes encoding melatonin receptors (zMelR that mediate the circadian message to the entire organism. Moreover, the effects of prenatal cocaine depend on the time of treatment, being more robust during the day, independent of whether the embryos are raised under the light-dark cycle or in constant light. The latter suggests involvement of the inherited circadian factors. The principal circadian hormone, melatonin, counteracts the effects of cocaine on neuronal development and gene expression, acting via specific melatonin receptors.These findings demonstrate that, in a diurnal vertebrate, prenatal cocaine can acutely dysregulate the expression of circadian genes and those affecting melatonin signaling, growth and neurotransmission, while repeated cocaine exposure can alter neuronal development. Daily variation in these effects of cocaine and their attenuation by melatonin suggest

  18. CIRCADIAN RHYTMICITY AND DEPRESSION

    Directory of Open Access Journals (Sweden)

    Peter Pregelj

    2008-11-01

    There is a grooving evidence that dysfunction in circadian rhythm regulation andmelatonergic system function is involved in depression pathogenesis. It is known thatclinically used antidepressants have influence on melatonergic system, probably throughchanged ratio between melatonergic type 1 and 2 receptors. With the clinical use of newcompounds like agomelatine that directly regulates melatonergic system new opportunities in depression treatment emerged

  19. Moire interferometry and hole drilling system for residual stress measurement

    Science.gov (United States)

    Ya, Min; Dai, Fulong; Lu, Jian

    2003-04-01

    A combined system of four beams moire interferometer and incremental hole-driling machine was designed and applied for residual stress measurement. Two typical experiments were done using this system: non-uniform in-depth residual stress measurement of an ultrasonic shot-peening Aluminum plate; non-uniform in-plane residual stress measurement of an elastic-plastic Aluminum bent beam. Experiments results show good accordant with other measurement results and theory analysis results.

  20. Circadian Rhythms in Cyanobacteria

    Science.gov (United States)

    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

  1. Mini Review: Circadian Clocks, Stress and Immunity

    Directory of Open Access Journals (Sweden)

    Rebecca eDumbell

    2016-05-01

    Full Text Available In mammals, molecular circadian clocks are present in most cells of the body, and this circadian network plays an important role in synchronizing physiological processes and behaviors to the appropriate time of day. The hypothalamic-pituitary-adrenal endocrine axis regulates the response to acute and chronic stress, acting through its final effectors – glucocorticoids – released from the adrenal cortex. Glucocorticoid secretion, characterized by its circadian rhythm, has an important role in synchronizing peripheral clocks and rhythms downstream of the master circadian pacemaker in the suprachiasmatic nucleus. Finally, glucocorticoids are powerfully anti-inflammatory, and recent work has implicated the circadian clock in various aspects and cells of the immune system, suggesting a tight interplay of stress and circadian systems in the regulation of immunity. This mini-review summarizes our current understanding of the role of the circadian clock network in both, the HPA axis and the immune system, and discusses their interactions.

  2. The Circadian System: A Regulatory Feedback Network of Periphery and Brain.

    Science.gov (United States)

    Buijs, Frederik N; León-Mercado, Luis; Guzmán-Ruiz, Mara; Guerrero-Vargas, Natali N; Romo-Nava, Francisco; Buijs, Ruud M

    2016-05-01

    Circadian rhythms are generated by the autonomous circadian clock, the suprachiasmatic nucleus (SCN), and clock genes that are present in all tissues. The SCN times these peripheral clocks, as well as behavioral and physiological processes. Recent studies show that frequent violations of conditions set by our biological clock, such as shift work, jet lag, sleep deprivation, or simply eating at the wrong time of the day, may have deleterious effects on health. This infringement, also known as circadian desynchronization, is associated with chronic diseases like diabetes, hypertension, cancer, and psychiatric disorders. In this review, we will evaluate evidence that these diseases stem from the need of the SCN for peripheral feedback to fine-tune its output and adjust physiological processes to the requirements of the moment. This feedback can vary from neuronal or hormonal signals from the liver to changes in blood pressure. Desynchronization renders the circadian network dysfunctional, resulting in a breakdown of many functions driven by the SCN, disrupting core clock rhythms in the periphery and disorganizing cellular processes that are normally driven by the synchrony between behavior and peripheral signals with neuronal and humoral output of the hypothalamus. Consequently, we propose that the loss of synchrony between the different elements of this circadian network as may occur during shiftwork and jet lag is the reason for the occurrence of health problems. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

  3. Can exercise regulate the circadian system of adolescents? Novel implications for the treatment of delayed sleep-wake phase disorder.

    Science.gov (United States)

    Richardson, Cele E; Gradisar, Michael; Short, Michelle A; Lang, Christin

    2017-08-01

    Adolescents are vulnerable to inadequate sleep due to a unique constellation of risk factors. In particular, the puberty-related phase delay in the timing of the circadian system postpones the onset of sleep. Resultantly, disordered sleep is common among teenagers and young adults, with the most common sleep problem being delayed sleep wake-phase disorder (DSWPD). Although current treatments for DSWPD show promise, novel ways to improve our youth's sleep are needed. The purpose of this review is to critically evaluate the evidence for the role of exercise as a method to shift and/or regulate circadian timing, and thus improve sleep, in adolescents and young adults. A growing body of evidence suggests that nocturnal exercise can delay circadian timing. However, exercise administered at different times of the 24-h day may result in phase advances, particularly when the timing of exercise is gradually advanced in small daily increments. The implications of these results for young people's sleep health are discussed and suggestions are provided for ways that exercise could be used clinically, to improve the treatment of DSWPD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Is the food-entrainable circadian oscillator in the digestive system?

    Science.gov (United States)

    Davidson, A. J.; Poole, A. S.; Yamazaki, S.; Menaker, M.

    2003-01-01

    Food-anticipatory activity (FAA) is the increase in locomotion and core body temperature that precedes a daily scheduled meal. It is driven by a circadian oscillator but is independent of the suprachiasmatic nuclei. Recent results that reveal meal-entrained clock gene expression in rat and mouse peripheral organs raise the intriguing possibility that the digestive system is the site of the feeding-entrained oscillator (FEO) that underlies FAA. We tested this possibility by comparing FAA and Per1 rhythmicity in the digestive system of the Per1-luciferase transgenic rat. First, rats were entrained to daytime restricted feeding (RF, 10 days), then fed ad libitum (AL, 10 days), then food deprived (FD, 2 days). As expected FAA was evident during RF and disappeared during subsequent AL feeding, but returned at the correct phase during deprivation. The phase of Per1 in liver, stomach and colon shifted from a nocturnal to a diurnal peak during RF, but shifted back to nocturnal phase during the subsequent AL and remained nocturnal during food deprivation periods. Second, rats were entrained to two daily meals at zeitgeber time (ZT) 0400 and ZT 1600. FAA to both meals emerged after about 10days of dual RF. However, all tissues studied (all five liver lobes, esophagus, antral stomach, body of stomach, colon) showed entrainment consistent with only the night-time meal. These two results are inconsistent with the hypothesis that FAA arises as an output of rhythms in the gastrointestinal (GI) system. The results also highlight an interesting diversity among peripheral oscillators in their ability to entrain to meals and the direction of the phase shift after RF ends.

  5. Interdependence of nutrient metabolism and the circadian clock system: Importance for metabolic health

    Directory of Open Access Journals (Sweden)

    Aleix Ribas-Latre

    2016-03-01

    Major conclusions: Targeted use of specific nutrients based on chronotype has the potential for immense clinical utility in the future. Macronutrients and micronutrients have the ability to function as zeitgebers for the clock by activating or modulating specific clock proteins or accessory proteins (such as nuclear receptors. Circadian clock control by nutrients can be tissue-specific. With a better understanding of the mechanisms that support nutrient-induced circadian control in specific tissues, human chronotype and SNP information might eventually be used to tailor nutritional regimens for metabolic disease treatment and thus be an important part of personalized medicine's future.

  6. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    Keywords. Circadian rhythms, biological clocks, geophysical cycles, en- trainment. Living organisms ranging from bacteria to human beings exhibit 24-h rhythms in various behaviours and physiological processes. Matching of the period of such rhythms with that of the daily environmental cycles gives an impression that.

  7. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    rhythms especially their endogenous, self-sustained nature, ability to entrain to environmental cycles and. PRCs, greatly resemble those of self-sustained physical oscillators; which led them to propose that circadian rhythms function like physical oscillators and named such biological oscillators as 'endogenous self- ...

  8. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Circadian Rhythms: Why do Living Organisms Have Them? Koustubh M Vaze K L Nikhil Vijay Kumar Sharma. Series Article Volume 19 Issue 2 February 2014 pp 175-189 ...

  9. Effect of crop residue management and cropping system on pearl ...

    African Journals Online (AJOL)

    Retaining crop residues in the field and using legume-based crop rotations have been suggested as ways to simultaneously increase yields per unit area and replenish soil nutrients. The objective of this study was to investigate the influence of two cropping systems and three crop residue management practices on grain ...

  10. Development of an NPP residual lifetime evaluation system

    International Nuclear Information System (INIS)

    Regano, M.; Ibanez, M.; Hevia, F.

    1993-01-01

    Various reasons have given rise to the need for residual life management of Spain's nuclear power plants which lead to the a project for the development of a residual lifetime evaluation system managed by UNESA and supported by the owner groups. This project is described. 1 fig

  11. Functional analysis of Casein Kinase 1 in a minimal circadian system.

    Directory of Open Access Journals (Sweden)

    Gerben van Ooijen

    Full Text Available The Earth's rotation has driven the evolution of cellular circadian clocks to facilitate anticipation of the solar cycle. Some evidence for timekeeping mechanism conserved from early unicellular life through to modern organisms was recently identified, but the components of this oscillator are currently unknown. Although very few clock components appear to be shared across higher species, Casein Kinase 1 (CK1 is known to affect timekeeping across metazoans and fungi, but has not previously been implicated in the circadian clock in the plant kingdom. We now show that modulation of CK1 function lengthens circadian rhythms in Ostreococcustauri, a unicellular marine algal species at the base of the green lineage, separated from humans by ~1.5 billion years of evolution. CK1 contributes to timekeeping in a phase-dependent manner, indicating clock-mediated gating of CK1 activity. Label-free proteomic analyses upon overexpression as well as inhibition revealed CK1-responsive phosphorylation events on a set of target proteins, including highly conserved potentially clock-relevant cellular regulator proteins. These results have major implications for our understanding of cellular timekeeping and can inform future studies in any circadian organism.

  12. Response of the Human Circadian System to Millisecond Flashes of Light

    Science.gov (United States)

    2011-07-01

    sleep, including daily use of antihistamines or antidepressants. Subjects were of intermediate chronotype as determined by the Horne-Östberg...study of sleep and circadian rhythms. Sleep 26: 342–392. 12. Murphy PJ, Myers BL, Badia P (1996) Nonsteroidal anti-inflammatory drugs alter body

  13. Circadian blood pressure and systemic haemodynamics during 42 days of 6 degrees head-down tilt

    NARCIS (Netherlands)

    Voogel, A. J.; Stok, W. J.; Pretorius, P. J.; van Montfrans, G. A.; Langewouters, G. J.; Karemaker, J. M.

    1997-01-01

    Head-down tilted bedrest is a ground-based microgravity simulation model. Since in this position the influence of chief external determinants of circadian blood pressure variation, i.e. activity and posture, are reduced, it may reveal endogenous oscillatory factors. The effects of 42 days of 6

  14. The circadian system of patients with bipolar disorder differs in episodes of mania and depression

    Czech Academy of Sciences Publication Activity Database

    Nováková, Marta; Praško, J.; Látalová, K.; Sládek, Martin; Sumová, Alena

    2015-01-01

    Roč. 17, č. 3 (2015), s. 303-314 ISSN 1398-5647 R&D Projects: GA MZd(CZ) NT11474 Institutional support: RVO:67985823 Keywords : bipolar disorder * circadian * clock gene * melatonin * Nr1d1 * Per1 Subject RIV: FH - Neurology Impact factor: 4.882, year: 2015

  15. Circadian Rhythms in Fear Conditioning: An Overview of Behavioral, Brain System, and Molecular Interactions

    Directory of Open Access Journals (Sweden)

    Anne Albrecht

    2017-01-01

    Full Text Available The formation of fear memories is a powerful and highly evolutionary conserved mechanism that serves the behavioral adaptation to environmental threats. Accordingly, classical fear conditioning paradigms have been employed to investigate fundamental molecular processes of memory formation. Evidence suggests that a circadian regulation mechanism allows for a timestamping of such fear memories and controlling memory salience during both their acquisition and their modification after retrieval. These mechanisms include an expression of molecular clocks in neurons of the amygdala, hippocampus, and medial prefrontal cortex and their tight interaction with the intracellular signaling pathways that mediate neural plasticity and information storage. The cellular activities are coordinated across different brain regions and neural circuits through the release of glucocorticoids and neuromodulators such as acetylcholine, which integrate circadian and memory-related activation. Disturbance of this interplay by circadian phase shifts or traumatic experience appears to be an important factor in the development of stress-related psychopathology, considering these circadian components are of critical importance for optimizing therapeutic approaches to these disorders.

  16. Moderate Changes in the Circadian System of Alzheimer's Disease Patients Detected in Their Home Environment

    Czech Academy of Sciences Publication Activity Database

    Weissová, Kamila; Bartoš, A.; Sládek, Martin; Nováková, Marta; Sumová, Alena

    2016-01-01

    Roč. 11, č. 1 (2016), e0146200 E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : circadian * melatonin * clock gene * Alzheimer's disease Subject RIV: FH - Neurology Impact factor: 2.806, year: 2016

  17. Day-night contrast as source of health for the human circadian system.

    Science.gov (United States)

    Martinez-Nicolas, Antonio; Madrid, Juan Antonio; Rol, Maria Angeles

    2014-04-01

    Modern societies are characterized by a 24/7 lifestyle (LS) with no environmental differences between day and night, resulting in weak zeitgebers (weak day light, absence of darkness during night, constant environmental temperature, sedentary LS and frequent snacking), and as a consequence, in an impaired circadian system (CS) through a process known as chronodisruption. Both weak zeitgebers and CS impairment are related to human pathologies (certain cancers, metabolic syndrome and affective and cognitive disorders), but little is known about how to chronoenhance the CS. The aim of this work is to propose practical strategies for chronoenhancement, based on accentuating the day/night contrast. For this, 131 young subjects were recruited, and their wrist temperature (WT), activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. Subjects with high contrast (HC) and low contrast (LC) for each variable were selected to analyze the HC effect in activity, body position, environmental temperature, light exposure and sleep would have on WT. We found that HC showed better rhythms than LC for every variable except sleep. Subjects with HC and LC for WT also demonstrated differences in LS, where HC subjects had a slightly advanced night phase onset and a general increase in day/night contrast. In addition, theoretical high day/night contrast calculated using mathematical models suggests an improvement by means of LS contrast. Finally, some individuals classified as belonging to the HC group in terms of WT when they are exposed to the LS characteristic of the LC group, while others exhibit WT arrhythmicity despite their good LS habits, revealing two different WT components: an exogenous component modified by LS and another endogenous component that is refractory to it. Therefore, intensifying day/night contrast in subject's LS has proven to be a feasible measure to chronoenhance the CS.

  18. Circadian rhythm and its role in malignancy

    Directory of Open Access Journals (Sweden)

    Mahmood Saqib

    2010-03-01

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

  19. Circadian clocks, epigenetics, and cancer

    KAUST Repository

    Masri, Selma

    2015-01-01

    The interplay between circadian rhythm and cancer has been suggested for more than a decade based on the observations that shift work and cancer incidence are linked. Accumulating evidence implicates the circadian clock in cancer survival and proliferation pathways. At the molecular level, multiple control mechanisms have been proposed to link circadian transcription and cell-cycle control to tumorigenesis.The circadian gating of the cell cycle and subsequent control of cell proliferation is an area of active investigation. Moreover, the circadian clock is a transcriptional system that is intricately regulated at the epigenetic level. Interestingly, the epigenetic landscape at the level of histone modifications, DNA methylation, and small regulatory RNAs are differentially controlled in cancer cells. This concept raises the possibility that epigenetic control is a common thread linking the clock with cancer, though little scientific evidence is known to date.This review focuses on the link between circadian clock and cancer, and speculates on the possible connections at the epigenetic level that could further link the circadian clock to tumor initiation or progression.

  20. Effects of blue light on the circadian system and eye physiology

    OpenAIRE

    Tosini, Gianluca; Ferguson, Ian; Tsubota, Kazuo

    2016-01-01

    Light-emitting diodes (LEDs) have been used to provide illumination in industrial and commercial environments. LEDs are also used in TVs, computers, smart phones, and tablets. Although the light emitted by most LEDs appears white, LEDs have peak emission in the blue light range (400?490 nm). The accumulating experimental evidence has indicated that exposure to blue light can affect many physiologic functions, and it can be used to treat circadian and sleep dysfunctions. However, blue light ca...

  1. Circadian System and Melatonin Hormone: Risk Factors for Complications during Pregnancy

    OpenAIRE

    Valenzuela, F. J.; Vera, J.; Venegas, C.; Pino, F.; Lagunas, C.

    2015-01-01

    Pregnancy is a complex and well-regulated temporal event in which several steps are finely orchestrated including implantation, decidualization, placentation, and partum and any temporary alteration has serious effects on fetal and maternal health. Interestingly, alterations of circadian rhythms (i.e., shiftwork) have been correlated with increased risk of preterm delivery, intrauterine growth restriction, and preeclampsia. In the last few years evidence is accumulating that the placenta may ...

  2. Neurohormones as putative circadian clock output signals in the central nervous system of two cricket species

    Czech Academy of Sciences Publication Activity Database

    Sehadová, H.; Shao, Q. M.; Sehnal, František; Takeda, M.

    2007-01-01

    Roč. 328, č. 1 (2007), s. 239-255 ISSN 0302-766X Grant - others:Japan Society for the Promotion of Science(JP) 99L01205; Japan Society for the Promotion of Science(JP) ID No. P04197 Institutional research plan: CEZ:AV0Z50070508 Keywords : circadian rhythm * corazonin * CCAP Subject RIV: ED - Physiology Impact factor: 2.613, year: 2007

  3. Mechanism of the circadian clock in physiology

    Science.gov (United States)

    Richards, Jacob

    2013-01-01

    It has been well established that the circadian clock plays a crucial role in the regulation of almost every physiological process. It also plays a critical role in pathophysiological states including those of obesity and diabetes. Recent evidence has highlighted the potential for targeting the circadian clock as a potential drug target. New studies have also demonstrated the existence of “clock-independent effects” of the circadian proteins, leading to exciting new avenues of research in the circadian clock field in physiology. The goal of this review is to provide an introduction to and overview of the circadian clock in physiology, including mechanisms, targets, and role in disease states. The role of the circadian clocks in the regulation of the cardiovascular system, renal function, metabolism, the endocrine system, immune, and reproductive systems will be discussed. PMID:23576606

  4. Gnaz couples the circadian and dopaminergic system to G protein-mediated signaling in mouse photoreceptors.

    Directory of Open Access Journals (Sweden)

    Patrick Vancura

    Full Text Available The mammalian retina harbors a circadian clockwork that regulates vision and promotes healthiness of retinal neurons, mainly through directing the rhythmic release of the neurohormones dopamine-acting on dopamine D4 receptors-and melatonin-acting on MT1 and MT2 receptors. The gene Gnaz-a unique Gi/o subfamily member-was seen in the present study to be expressed in photoreceptors where its protein product Gαz shows a daily rhythm in its subcellular localization. Apart from subcellular localization, Gnaz displays a daily rhythm in expression-with peak values at night-in preparations of the whole retina, microdissected photoreceptors and photoreceptor-related pinealocytes. In retina, Gnaz rhythmicity was observed to persist under constant darkness and to be abolished in retina deficient for Clock or dopamine D4 receptors. Furthermore, circadian regulation of Gnaz was disturbed in the db/db mouse, a model of diabetic retinopathy. The data of the present study suggest that Gnaz links the circadian clockwork-via dopamine acting on D4 receptors-to G protein-mediated signaling in intact but not diabetic retina.

  5. Investigation of the Phaseolus vulgaris circadian clock and the repressive role of the PvTOC1 factor by a newly established in vitro system.

    Science.gov (United States)

    Galeou, Angeliki; Roussis, Andreas; Prombona, Anastasia

    2018-03-01

    The circadian clock is crucial for the synchronization of an organism's physiology and metabolism with the geophysical time. In plants, previous work on the common bean (Phaseolus vulgaris) has identified various differing aspects of clock function compared to the widely studied Arabidopsis thaliana clock. However, transformation of legumes for the study of the circadian clock regulatory mechanisms is extremely laborious. In the present work, we describe an easy-to-follow and rapid method of preparing bean leaf protoplasts with high transformation potential and a functional circadian clock. In this system, we show that application of trichostatin A differentially changes the expression levels of several clock genes. More importantly, we investigate the effect of the clock protein PvTOC1 (Phaseolus vulgaris TIMING OF CAB EXPRESSION 1) on the activity of bean circadian promoters. We present new evidence on the function of PvTOC1 as a repressor of the promoter activity of its own gene, mediated by its conserved CCT (CONSTANS, CO-LIKE and TOC1) domain. Using our protoplast system we were able to uncover functions of the bean circadian clock and to identify an additional target of the PvTOC1clock transcription factor, not previously reported. Copyright © 2018 Elsevier GmbH. All rights reserved.

  6. Biogas systems for sisal and other agro-industrial residues

    Energy Technology Data Exchange (ETDEWEB)

    Jungersen, G. [Danish Technological Inst., Section for Biotechnology, Taastrup (Denmark)

    1997-12-31

    Most of the East-African agro-industries are generating very large quantities of organic residues from production and processing of different crops. In the East-African Region the most important of these crops are: Sisal, Sugar, Coffee, Cashew nuts and Pineapple. In other 3. world countries, Palm oil and Cassava (Tapioca starch) processing are main producers of organic waste products. Moreover, large quantities of organic residues are generated from other food processing activities like breweries, consumption of bananas etc. The following pages give examples of setups and system designs of anaerobic treatment systems for some of the residues mentioned above. When considering anaerobic treatment of sisal residues, which constitutes the main agro-industrial biomass resource in Tanzania, two major issues should be considered: Optimal reactor set-up and performance; And optionally, potential methods for pre-treatment of fibre fraction in order to increase the methane yield. The sisal liquid residues are degraded very fast and efficiently in UASB systems. At COD loading rates less than 11 kg COD/m{sup 3} x day, the reduction in organic matter is more than 90% and methane yields obtained are between 373 and 377 ml CH{sub 4}/g COD reduced. The treatment of sisal solid residues in CSTR systems has been examined both at mesophilic (37 deg. C) and thermophilic temperatures (55 deg. C.). (EG)

  7. Circadian Differences in the Contribution of the Brain Renin-Angiotensin System in Genetically Hypertensive Mice

    Directory of Open Access Journals (Sweden)

    Kristy L. Jackson

    2018-03-01

    Full Text Available Objective: Genetically hypertensive BPH/2J mice are recognized as a neurogenic model of hypertension, primarily based on sympathetic overactivity and greater neuronal activity in cardiovascular regulatory brain regions. Greater activity of the central renin angiotensin system (RAS and reactive oxygen species (ROS reportedly contribute to other models of hypertension. Importantly the peripheral RAS contributes to the hypertension in BPH/2J mice, predominantly during the dark period of the 24 h light cycle. The aim of the present study was to determine whether central AT1 receptor stimulation and the associated ROS signaling contribute to hypertension in BPH/2J mice in a circadian dependent manner.Methods: Blood pressure (BP was measured in BPH/2J and normotensive BPN/3J mice (n = 7–8 via pre-implanted telemetry devices. Acute intracerebroventricular (ICV microinjections of AT1 receptor antagonist, candesartan, and the superoxide dismutase (SOD mimetic, tempol, were administered during the dark and light period of the 24 h light cycle via a pre-implanted ICV guide cannula. In separate mice, the BP effect of ICV infusion of the AT1 receptor antagonist losartan for 7 days was compared with subcutaneous infusion to determine the contribution of the central RAS to hypertension in BPH/2J mice.Results: Candesartan administered ICV during the dark period induced depressor responses which were 40% smaller in BPH/2J than BPN/3J mice (Pstrain < 0.05, suggesting AT1 receptor stimulation may contribute less to BP maintenance in BPH/2J mice. During the light period candesartan had minimal effect on BP in either strain. ICV tempol had comparable effects on BP between strains during the light and dark period (Pstrain > 0.08, suggesting ROS signaling is also not contributing to the hypertension in BPH/2J mice. Chronic ICV administration of losartan (22 nmol/h had minimal effect on BPN/3J mice. By contrast in BPH/2J mice, both ICV and subcutaneously administered

  8. Systems for harvesting and handling cotton plant residue

    Energy Technology Data Exchange (ETDEWEB)

    Coates, W. [Univ. of Arizona, Tucson, AZ (United States)

    1993-12-31

    In the warmer regions of the United States, cotton plant residue must be buried to prevent it from serving as an overwintering site for insect pests such as the pink bollworm. Most of the field operations used to bury the residue are high energy consumers and tend to degrade soil structure, thereby increasing the potential for erosion. The residue is of little value as a soil amendment and consequently is considered a negative value biomass. A commercial system to harvest cotton plant residue would be of both economic and environmental benefit to cotton producers. Research has been underway at the University of Arizona since the spring of 1991 to develop a commercially viable system for harvesting cotton plant residue. Equipment durability, degree of densification, energy required, cleanliness of the harvested material, and ease of product handling and transport are some of the performance variables which have been measured. Two systems have proven superior. In both, the plants are pulled from the ground using an implement developed specifically for the purpose. In one system, the stalks are baled using a large round baler, while in the other the stalks are chopped with a forage harvester, and then made into packages using a cotton module maker. Field capacities, energy requirements, package density and durability, and ease of handling with commercially available equipment have been measured for both systems. Selection of an optimum system for a specific operation depends upon end use of the product, and upon equipment availability.

  9. Persistent organochlorine pesticide residues in freshwater systems ...

    African Journals Online (AJOL)

    , heptachlor and endosulfan were determined in water and sediment samples of freshwater systems in the Eastern Cape Province of South Africa that receive runoff from agricultural lands and effluents from industries. The organochlorine ...

  10. Circadian Tick-Talking Across the Neuroendocrine System and Suprachiasmatic Nuclei Circuits: The Enigmatic Communication Between the Molecular and Electrical Membrane Clocks.

    Science.gov (United States)

    Belle, M D C

    2015-07-01

    As with many processes in nature, appropriate timing in biological systems is of paramount importance. In the neuroendocrine system, the efficacy of hormonal influence on major bodily functions, such as reproduction, metabolism and growth, relies on timely communication within and across many of the brain's homeostatic systems. The activity of these circuits is tightly orchestrated with the animal's internal physiological demands and external solar cycle by a master circadian clock. In mammals, this master clock is located in the hypothalamic suprachiasmatic nucleus (SCN), where the ensemble activity of thousands of clock neurones generates and communicates circadian time cues to the rest of the brain and body. Many regions of the brain, including areas with neuroendocrine function, also contain local daily clocks that can provide feedback signals to the SCN. Although much is known about the molecular processes underpinning endogenous circadian rhythm generation in SCN neurones and, to a lesser extent, extra-SCN cells, the electrical membrane clock that acts in partnership with the molecular clockwork to communicate circadian timing across the brain is poorly understood. The present review focuses on some circadian aspects of reproductive neuroendocrinology and processes involved in circadian rhythm communication in the SCN, aiming to identify key gaps in our knowledge of cross-talk between our daily master clock and neuroendocrine function. The intention is to highlight our surprisingly limited understanding of their interaction in the hope that this will stimulate future work in these areas. © 2015 The Author. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of The British Society for Neuroendocrinology.

  11. Valve arrangement for a nuclear plant residual heat removal system

    International Nuclear Information System (INIS)

    Fidler, G.L.; Hill, R.A.; Carrera, J.P.

    1978-01-01

    Disclosed is an improved valve arrangement for a two-train Residual Heat Removal System (RHRS) of a nuclear reactor plant which ensures operational integrity of the system under single failure circumstances including loss of one of two electrical power sources

  12. Circadian and Wakefulness-Sleep Modulation of Cognition in Humans

    Directory of Open Access Journals (Sweden)

    Kenneth P Wright

    2012-04-01

    Full Text Available Cognitive and affective processes vary over the course of the 24 hour day. Time of day dependent changes in human cognition are modulated by an internal circadian timekeeping system with a near-24-hour period. The human circadian timekeeping system interacts with sleep-wakefulness regulatory processes to modulate brain arousal, neurocognitive and affective function. Brain arousal is regulated by ascending brain stem, basal forebrain and hypothalamic arousal systems and inhibition or disruption of these systems reduces brain arousal, impairs cognition, and promotes sleep. The internal circadian timekeeping system modulates cognition and affective function by projections from the master circadian clock, located in the hypothalamic suprachiasmatic nuclei, to arousal and sleep systems and via clock gene oscillations in brain tissues. Understanding the basic principles of circadian and wakefulness-sleep physiology can help to recognize how the circadian system modulates human cognition and influences learning, memory and emotion. Developmental changes in sleep and circadian processes and circadian misalignment in circadian rhythm sleep disorders have important implications for learning, memory and emotion. Overall, when wakefulness occurs at appropriate internal biological times, circadian clockwork benefits human cognitive and emotion function throughout the lifespan. Yet, when wakefulness occurs at inappropriate biological times because of environmental pressures (e.g., early school start times, long work hours that include work at night, shift work, jet lag or because of circadian rhythm sleep disorders, the resulting misalignment between circadian and wakefulness-sleep physiology leads to impaired cognitive performance, learning, emotion, and safety.

  13. Synchronization of biological clock neurons by light and peripheral feedback systems promotes circadian rhythms and health

    Directory of Open Access Journals (Sweden)

    Ashna eRamkisoensing

    2015-06-01

    Full Text Available In mammals, the suprachiasmatic nucleus (SCN functions as a circadian clock that drives 24-hour rhythms in both physiology and behavior. The SCN is a multicellular oscillator in which individual neurons function as cell-autonomous oscillators. The production of a coherent output rhythm is dependent upon mutual synchronization among single cells and requires both synaptic communication and gap junctions. Changes in phase synchronization between individual cells have consequences on the amplitude of the SCN’s electrical activity rhythm, and these changes play a major role in the ability to adapt to seasonal changes. Both aging and sleep deprivation negatively affect the circadian amplitude of the SCN, whereas behavioral activity (i.e., exercise has a positive effect on amplitude. Given that the amplitude of the SCN’s electrical activity rhythm is essential for achieving robust rhythmicity in physiology and behavior, the mechanisms that underlie neuronal synchronization warrant further study. A growing body of evidence suggests that the functional integrity of the SCN contributes to health, well-being, cognitive performance, and alertness; in contrast, deterioration of the 24-hour rhythm is a risk factor for neurodegenerative disease, cancer, depression, and sleep disorders.

  14. Circadian timekeeping : from basic clock function to implications for health

    NARCIS (Netherlands)

    Lucassen, Eliane Alinda

    2016-01-01

    In modern society, circadian rhythms and sleep are often disturbed, which may negatively affect health. This thesis examines these associations and focuses on the basic functioning of sleep and the circadian system in mice and in humans. Circadian rhythms are orchestrated by ~20,000 neurons in the

  15. Effects of blue light on the circadian system and eye physiology.

    Science.gov (United States)

    Tosini, Gianluca; Ferguson, Ian; Tsubota, Kazuo

    2016-01-01

    Light-emitting diodes (LEDs) have been used to provide illumination in industrial and commercial environments. LEDs are also used in TVs, computers, smart phones, and tablets. Although the light emitted by most LEDs appears white, LEDs have peak emission in the blue light range (400-490 nm). The accumulating experimental evidence has indicated that exposure to blue light can affect many physiologic functions, and it can be used to treat circadian and sleep dysfunctions. However, blue light can also induce photoreceptor damage. Thus, it is important to consider the spectral output of LED-based light sources to minimize the danger that may be associated with blue light exposure. In this review, we summarize the current knowledge of the effects of blue light on the regulation of physiologic functions and the possible effects of blue light exposure on ocular health.

  16. Effects of blue light on the circadian system and eye physiology

    Science.gov (United States)

    Ferguson, Ian; Tsubota, Kazuo

    2016-01-01

    Light-emitting diodes (LEDs) have been used to provide illumination in industrial and commercial environments. LEDs are also used in TVs, computers, smart phones, and tablets. Although the light emitted by most LEDs appears white, LEDs have peak emission in the blue light range (400–490 nm). The accumulating experimental evidence has indicated that exposure to blue light can affect many physiologic functions, and it can be used to treat circadian and sleep dysfunctions. However, blue light can also induce photoreceptor damage. Thus, it is important to consider the spectral output of LED-based light sources to minimize the danger that may be associated with blue light exposure. In this review, we summarize the current knowledge of the effects of blue light on the regulation of physiologic functions and the possible effects of blue light exposure on ocular health. PMID:26900325

  17. Circadian signaling in the Northern krill Meganyctiphanes norvegica: In silico prediction of the protein components of a putative clock system using a publicly accessible transcriptome.

    Science.gov (United States)

    Christie, Andrew E; Yu, Andy; Pascual, Micah G

    2018-02-01

    The Northern krill Meganyctiphanes norvegica is a significant component of the zooplankton community in many regions of the North Atlantic Ocean. In the areas it inhabits, M. norvegica is of great importance ecologically, as it is both a major consumer of phytoplankton/small zooplankton and is a primary food source for higher-level consumers. One behavior of significance for both feeding and predator avoidance in Meganyctiphanes is diel vertical migration (DVM), i.e., a rising from depth at dusk and a return to depth at dawn. In this and other euphausiids, an endogenous circadian pacemaker is thought, at least in part, to control DVM. Currently, there is no information concerning the identity of the genes/proteins that comprise the M. norvegica circadian system. In fact, there is little information concerning the molecular underpinnings of circadian rhythmicity in crustaceans generally. Here, a publicly accessible transcriptome was used to identify the molecular components of a putative Meganyctiphanes circadian system. A complete set of core clock proteins was deduced from the M. norvegica transcriptome (clock, cryptochrome 2, cycle, period and timeless), as was a large suite of proteins that likely function as modulators of the core clock (e.g., doubletime), or serves as inputs to it (cryptochrome 1) or outputs from it (pigment dispersing hormone). This is the first description of a "complete" (core clock through putative output pathway signals) euphausiid clock system, and as such, provides a foundation for initiating molecular investigations of circadian signaling in M. norvegica and other krill species, including how clock systems may regulate DVM and other behaviors. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools at our disposal over the past four decades has enabled discovery of the genetic and molecular bases of circadian rhythmicity.

  19. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2008-12-07

    Dec 7, 2008 ... system for the study of circadian rhythms primarily due to the availability of molecular genetic tools that enabled iden- tification of genes, proteins and neuronal groups that are es- sential components of the circadian machinery. Further, D. melanogaster exhibits robust and relatively easily measur-.

  20. The Neurospora circadian clock : simple or complex?

    NARCIS (Netherlands)

    Bell-Pedersen, Deborah; Crosthwaite, Susan K.; Lakin-Thomas, Patricia L.; Merrow, Martha; Økland, Merete

    2001-01-01

    The fungus Neurospora crassa is being used by a number of research groups as a model organism to investigate circadian (daily) rhythmicity. In this review we concentrate on recent work relating to the complexity of the circadian system in this organism. We discuss: the advantages of Neurospora as a

  1. Health condition and residual life of deteriorating technical systems

    Energy Technology Data Exchange (ETDEWEB)

    Reinertsen, Rune

    1997-12-31

    Many offshore installations in the Norwegian Sector of the North Sea approach the end of their useful life. The same is true of many power plants and technical systems in general. This thesis describes the theory and improves the methods for the determination of the health condition and residual life of technical systems. Rather than developing new methods it discusses new ways of using existing statistical methods. The main contributions are: (1) A survey of the literature of diagnosis, prediction and life extension for deteriorating technical systems, (2) A discussion of some consequences of selecting the wrong life model, (3) A description of problems related to the determination of mean residual life of non-repairable technical systems, (4) Presentation of the concept of `technical health` to describe the soundness of a system exposed to failure mechanisms, (5) A model for predicting the technical health and residual life of a corroding system, (6) Recommends requirements and methods for using expert knowledge in safety and reliability analysis, (7) A general inspection strategy for system fault diagnosis by using Shannon entropy, (8) Points out weaknesses and strengths of risk measures used in the offshore industry today. 237 refs., 23 figs., 6 tabs.

  2. Circadian Clock, Cancer, and Chemotherapy

    Science.gov (United States)

    2015-01-01

    The circadian clock is a global regulatory system that interfaces with most other regulatory systems and pathways in mammalian organisms. Investigations of the circadian clock–DNA damage response connections have revealed that nucleotide excision repair, DNA damage checkpoints, and apoptosis are appreciably influenced by the clock. Although several epidemiological studies in humans and a limited number of genetic studies in mouse model systems have indicated that clock disruption may predispose mammals to cancer, well-controlled genetic studies in mice have not supported the commonly held view that circadian clock disruption is a cancer risk factor. In fact, in the appropriate genetic background, clock disruption may instead aid in cancer regression by promoting intrinsic and extrinsic apoptosis. Finally, the clock may affect the efficacy of cancer treatment (chronochemotherapy) by modulating the pharmacokinetics and pharmacodynamics of chemotherapeutic drugs as well as the activity of the DNA repair enzymes that repair the DNA damage caused by anticancer drugs. PMID:25302769

  3. Characteristic of oil palm residue for energy conversion system

    International Nuclear Information System (INIS)

    Muharnif; Zainal, Z.A.

    2006-01-01

    Malaysia is the major producer of palm oil in the world. It produces 8.5 tones per year (8.5 x 10 6 ty -1 ) of palm oil from 38.6 x 10 6 ty - 1 of fresh fruit bunches. Palm oil production generates large amounts of process residue such as fiber (5.4 x 10 6 ty - 1 ), shell (2.3 x 10 6 ty - 1 ), and empty fruit bunches (8.8 x 10 6 ty - 1 ). A large fraction of the fiber and much of the shell are used as fuel to generate process steam and electricity. The appropriate energy conversion system depends on the characteristic of the oil palm residue. In this paper, a description of characteristic of the oil palm residue is presented. The types of the energy conversion system presented are stoker type combustor and gasified. The paper focuses on the pulverized biomass material and the use of fluidized bed gasified. In the fluidized bed gasified, the palm shell and fiber has to be pulverized before feeding into gasified. For downdraft gasified and furnace, the palm shell and fiber can be used directly into the reactor for energy conversion. The heating value, burning characteristic, ash and moisture content of the oil palm residue are other parameters of the study

  4. Clustering-driven residue filter for profile measurement system.

    Science.gov (United States)

    Jiang, Jun; Cheng, Jun; Zhou, Ying; Chen, Guang

    2011-02-01

    The profile measurement system is widely used in industrial quality control, and phase unwrapping (PU) is a key technique. An algorithm-driven PU is often used to reduce the impact of noise-induced residues to retrieve the most reliable solution. However, measuring speed is lowered due to the searching of optimal integration paths or correcting of phase gradients. From the viewpoint of the rapidity of the system, this paper characterizes the noise-induced residues, and it proposes a clustering-driven residue filter based on a set of directional windows. The proposed procedure makes the wrapped phases included in the filtering window have more similar values, and it groups the correct and noisy phases into individual clusters along the local fringe direction adaptively. It is effective for the tightly packed fringes, and it converts the algorithm-driven PU to the residue-filtering-driven one. This improves the operating speed of the 3D reconstruction significantly. The tests performed on simulated and real projected fringes confirm the validity of our approach.

  5. Increased Sensitivity of the Circadian System to Temporal Changes in the Feeding Regime of Spontaneously Hypertensive Rats - A Potential Role for Bmal2 in the Liver

    Science.gov (United States)

    Nováková, Marta; Parkanová, Daniela; Sumová, Alena

    2013-01-01

    The mammalian timekeeping system generates circadian oscillations that rhythmically drive various functions in the body, including metabolic processes. In the liver, circadian clocks may respond both to actual feeding conditions and to the metabolic state. The temporal restriction of food availability to improper times of day (restricted feeding, RF) leads to the development of food anticipatory activity (FAA) and resets the hepatic clock accordingly. The aim of this study was to assess this response in a rat strain exhibiting complex pathophysiological symptoms involving spontaneous hypertension, an abnormal metabolic state and changes in the circadian system, i.e., in spontaneously hypertensive rats (SHR). The results revealed that SHR were more sensitive to RF compared with control rats, developing earlier and more pronounced FAA. Whereas in control rats, the RF only redistributed the activity profiles into two bouts (one corresponding to FAA and the other corresponding to the dark phase), in SHR the RF completely phase-advanced the locomotor activity according to the time of food presentation. The higher behavioral sensitivity to RF was correlated with larger phase advances of the hepatic clock in response to RF in SHR. Moreover, in contrast to the controls, RF did not suppress the amplitude of the hepatic clock oscillation in SHR. In the colon, no significant differences in response to RF between the two rat strains were detected. The results suggested the possible involvement of the Bmal2 gene in the higher sensitivity of the hepatic clock to RF in SHR because, in contrast to the Wistar rats, the rhythm of Bmal2 expression was advanced similarly to that of Bmal1 under RF. Altogether, the data demonstrate a higher behavioral and circadian responsiveness to RF in the rat strain with a cardiovascular and metabolic pathology and suggest a likely functional role for the Bmal2 gene within the circadian clock. PMID:24086613

  6. Increased sensitivity of the circadian system to temporal changes in the feeding regime of spontaneously hypertensive rats - a potential role for Bmal2 in the liver.

    Directory of Open Access Journals (Sweden)

    Lenka Polidarová

    Full Text Available The mammalian timekeeping system generates circadian oscillations that rhythmically drive various functions in the body, including metabolic processes. In the liver, circadian clocks may respond both to actual feeding conditions and to the metabolic state. The temporal restriction of food availability to improper times of day (restricted feeding, RF leads to the development of food anticipatory activity (FAA and resets the hepatic clock accordingly. The aim of this study was to assess this response in a rat strain exhibiting complex pathophysiological symptoms involving spontaneous hypertension, an abnormal metabolic state and changes in the circadian system, i.e., in spontaneously hypertensive rats (SHR. The results revealed that SHR were more sensitive to RF compared with control rats, developing earlier and more pronounced FAA. Whereas in control rats, the RF only redistributed the activity profiles into two bouts (one corresponding to FAA and the other corresponding to the dark phase, in SHR the RF completely phase-advanced the locomotor activity according to the time of food presentation. The higher behavioral sensitivity to RF was correlated with larger phase advances of the hepatic clock in response to RF in SHR. Moreover, in contrast to the controls, RF did not suppress the amplitude of the hepatic clock oscillation in SHR. In the colon, no significant differences in response to RF between the two rat strains were detected. The results suggested the possible involvement of the Bmal2 gene in the higher sensitivity of the hepatic clock to RF in SHR because, in contrast to the Wistar rats, the rhythm of Bmal2 expression was advanced similarly to that of Bmal1 under RF. Altogether, the data demonstrate a higher behavioral and circadian responsiveness to RF in the rat strain with a cardiovascular and metabolic pathology and suggest a likely functional role for the Bmal2 gene within the circadian clock.

  7. Molecular Mechanisms of Circadian Regulation During Spaceflight

    Science.gov (United States)

    Zanello, S. B.; Boyle, R.

    2012-01-01

    The physiology of both vertebrates and invertebrates follows internal rhythms coordinated in phase with the 24-hour daily light cycle. This circadian clock is governed by a central pacemaker, the suprachiasmatic nucleus (SCN) in the brain. However, peripheral circadian clocks or oscillators have been identified in most tissues. How the central and peripheral oscillators are synchronized is still being elucidated. Light is the main environmental cue that entrains the circadian clock. Under the absence of a light stimulus, the clock continues its oscillation in a free-running condition. In general, three functional compartments of the circadian clock are defined. The vertebrate retina contains endogenous clocks that control many aspects of retinal physiology, including retinal sensitivity to light, neurohormone synthesis (melatonin and dopamine), rod disk shedding, signalling pathways and gene expression. Neurons with putative local circadian rhythm generation are found among all the major neuron populations in the mammalian retina. In the mouse, clock genes and function are more localized to the inner retinal and ganglion cell layers. The photoreceptor, however, secrete melatonin which may still serve a an important circadian signal. The reception and transmission of the non-visual photic stimulus resides in a small subpopulation (1-3%) or retinal ganglion cells (RGC) that express the pigment melanopsin (Opn4) and are called intrisically photoreceptive RGC (ipRGC). Melanopsin peak absorption is at 420 nm and all the axons of the ipRGC reach the SCN. A common countermeasure for circadian re-entrainment utilizes blue-green light to entrain the circadian clock and mitigate the risk of fatigue and health and performance decrement due to circadian rhythm disruption. However, an effective countermeasure targeting the photoreceptor system requires that the basic circadian molecular machinery remains intact during spaceflight. We hypothesize that spaceflight may affect ip

  8. Coordination of the maize transcriptome by a conserved circadian clock

    Directory of Open Access Journals (Sweden)

    Harmon Frank G

    2010-06-01

    Full Text Available Abstract Background The plant circadian clock orchestrates 24-hour rhythms in internal physiological processes to coordinate these activities with daily and seasonal changes in the environment. The circadian clock has a profound impact on many aspects of plant growth and development, including biomass accumulation and flowering time. Despite recent advances in understanding the circadian system of the model plant Arabidopsis thaliana, the contribution of the circadian oscillator to important agronomic traits in Zea mays and other cereals remains poorly defined. To address this deficit, this study investigated the transcriptional landscape of the maize circadian system. Results Since transcriptional regulation is a fundamental aspect of circadian systems, genes exhibiting circadian expression were identified in the sequenced maize inbred B73. Of the over 13,000 transcripts examined, approximately 10 percent displayed circadian expression patterns. The majority of cycling genes had peak expression at subjective dawn and dusk, similar to other plant circadian systems. The maize circadian clock organized co-regulation of genes participating in fundamental physiological processes, including photosynthesis, carbohydrate metabolism, cell wall biogenesis, and phytohormone biosynthesis pathways. Conclusions Circadian regulation of the maize genome was widespread and key genes in several major metabolic pathways had circadian expression waveforms. The maize circadian clock coordinated transcription to be coincident with oncoming day or night, which was consistent with the circadian oscillator acting to prepare the plant for these major recurring environmental changes. These findings highlighted the multiple processes in maize plants under circadian regulation and, as a result, provided insight into the important contribution this regulatory system makes to agronomic traits in maize and potentially other C4 plant species.

  9. Circadian Biology: Uncoupling Human Body Clocks by Food Timing.

    Science.gov (United States)

    Vetter, Celine; Scheer, Frank A J L

    2017-07-10

    Synchrony of circadian rhythms between tissues/organs appears critical for health. A new study reports that meal timing, a modifiable temporal cue for the circadian system, can selectively uncouple circadian rhythms in metabolic physiology from the central circadian clock in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Residual HCRF rotation relative to the inertial coordinate system

    Science.gov (United States)

    Bobylev, V. V.

    2015-03-01

    VLBI measurements of the absolute proper motions of 23 radio stars have been collected from published data. These are stars with maser emission, or very young stars, or asymptotic-giant-branch stars. By comparing these measurements with the stellar proper motions from the optical catalogs of the Hipparcos Celestial Reference Frame (HCRF), we have found the components of the residual rotation vector of this frame relative to the inertial coordinate system: ( ω x , ω y , ω z ) = (-0.39, -0.51, -1.25) ± (0.58, 0.57, 0.56) mas yr-1. Based on all the available data, we have determined new values of the components of the residual rotation vector for the optical realization of the HCRF relative to the inertial coordinate system: ( ω x , ω y , ω z ) = (-0.15, +0.24,-0.53) ± (0.11, 0.10, 0.13) mas yr-1.

  11. The bipolarity of light and dark: A review on Bipolar Disorder and circadian cycles.

    Science.gov (United States)

    Abreu, T; Bragança, M

    2015-10-01

    Bipolar Disorder is characterized by episodes running the full mood spectrum, from mania to depression. Between mood episodes, residual symptoms remain, as sleep alterations, circadian cycle disturbances, emotional deregulation, cognitive impairment and increased risk for comorbidities. The present review intends to reflect about the most recent and relevant information concerning the biunivocal relation between bipolar disorder and circadian cycles. It was conducted a literature search on PubMed database using the search terms "bipolar", "circadian", "melatonin", "cortisol", "body temperature", "Clock gene", "Bmal1 gene", "Per gene", "Cry gene", "GSK3β", "chronotype", "light therapy", "dark therapy", "sleep deprivation", "lithum" and "agomelatine". Search results were manually reviewed, and pertinent studies were selected for inclusion as appropriate. Several studies support the relationship between bipolar disorder and circadian cycles, discussing alterations in melatonin, body temperature and cortisol rhythms; disruption of sleep/wake cycle; variations of clock genes; and chronotype. Some therapeutics for bipolar disorder directed to the circadian cycles disturbances are also discussed, including lithium carbonate, agomelatine, light therapy, dark therapy, sleep deprivation and interpersonal and social rhythm therapy. This review provides a summary of an extensive research for the relevant literature on this theme, not a patient-wise meta-analysis. In the future, it is essential to achieve a better understanding of the relation between bipolar disorder and the circadian system. It is required to establish new treatment protocols, combining psychotherapy, therapies targeting the circadian rhythms and the latest drugs, in order to reduce the risk of relapse and improve affective behaviour. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The role of the endocrine system in feeding-induced tissue-specific circadian entrainment.

    Science.gov (United States)

    Sato, Miho; Murakami, Mariko; Node, Koichi; Matsumura, Ritsuko; Akashi, Makoto

    2014-07-24

    The circadian clock is entrained to environmental cycles by external cue-mediated phase adjustment. Although the light input pathway has been well defined, the mechanism of feeding-induced phase resetting remains unclear. The tissue-specific sensitivity of peripheral entrainment to feeding suggests the involvement of multiple pathways, including humoral and neuronal signals. Previous in vitro studies with cultured cells indicate that endocrine factors may function as entrainment cues for peripheral clocks. However, blood-borne factors that are well characterized in actual feeding-induced resetting have yet to be identified. Here, we report that insulin may be involved in feeding-induced tissue-type-dependent entrainment in vivo. In ex vivo culture experiments, insulin-induced phase shift in peripheral clocks was dependent on tissue type, which was consistent with tissue-specific insulin sensitivity, and peripheral entrainment in insulin-sensitive tissues involved PI3K- and MAPK-mediated signaling pathways. These results suggest that insulin may be an immediate early factor in feeding-mediated tissue-specific entrainment. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Residual life estimation of electrical insulation system for rotating equipment

    International Nuclear Information System (INIS)

    Vashishtha, Y.D.; Gupta, A.K.; Bhattacharyya, A.K.; Verma, A.K.

    1994-01-01

    Residual life assessment gains significance towards the end of designed life for granting plant life extensions and resource planning for costly equipment replacement. A critical review of all the diagnostic techniques presently used to assess either health of insulation system or to infer qualitatively the remaining life for rotating machines is presented. However more emphasis is required on developing quantitative methods. This paper also formulates the experimental plan for progressively censored ageing tests, measurement of partial discharge parameters, micro-structural study for delamination and electrical tree growth and measurement of electrical breakdown strength. Partial discharge (PD) patterns, electrical tree growth and time to failure data shall be taken as training set for the neural network learning which can be useful to predict residual life with only one candidate parameter i.e. PD patterns. (author). 9 refs

  14. System Study: Residual Heat Removal 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-02-01

    This report presents an unreliability evaluation of the residual heat removal (RHR) system in two modes of operation (low-pressure injection in response to a large loss-of-coolant accident and post-trip shutdown-cooling) at 104 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RHR results.

  15. Use of Circadian Lighting System to improve night shift alertness and performance of NRC Headquarters Operations Officers

    International Nuclear Information System (INIS)

    Baker, T.L.; Morisseau, D.; Murphy, N.M.

    1995-01-01

    The Nuclear Regulatory Commission's (NRC) Headquarters Operations Officers (HOOs) receive and respond to events reported in the nuclear industry on a 24-hour basis. The HOOs have reported reduced alertness on the night shift, leading to a potential deterioration in their on-shift cognitive performance during the early morning hours. For some HOOs, maladaptation to the night shift was also reported to be the principal cause of: (a) reduced alertness during the commute to and from work, (b) poor sleep quality, and (c) personal lifestyle problems. ShiftWork Systems, Inc. (SWS) designed and installed a Circadian Lighting System (CLS) at both the Bethesda and Rockville HOO stations with the goal of facilitating the HOOs physiological adjustment to their night shift schedules. The data indicate the following findings: less subjective fatigue on night shifts; improved night shift alertness and mental performance; higher HOO confidence in their ability to assess event reports; longer, deeper and more restorative day sleep after night duty shifts; swifter adaptation to night work; and a safer commute, particularly for those with extensive drives

  16. Synchrony and desynchrony in circadian clocks: impacts on learning and memory

    Science.gov (United States)

    Krishnan, Harini C.

    2015-01-01

    Circadian clocks evolved under conditions of environmental variation, primarily alternating light dark cycles, to enable organisms to anticipate daily environmental events and coordinate metabolic, physiological, and behavioral activities. However, modern lifestyle and advances in technology have increased the percentage of individuals working in phases misaligned with natural circadian activity rhythms. Endogenous circadian oscillators modulate alertness, the acquisition of learning, memory formation, and the recall of memory with examples of circadian modulation of memory observed across phyla from invertebrates to humans. Cognitive performance and memory are significantly diminished when occurring out of phase with natural circadian rhythms. Disruptions in circadian regulation can lead to impairment in the formation of memories and manifestation of other cognitive deficits. This review explores the types of interactions through which the circadian clock modulates cognition, highlights recent progress in identifying mechanistic interactions between the circadian system and the processes involved in memory formation, and outlines methods used to remediate circadian perturbations and reinforce circadian adaptation. PMID:26286653

  17. Circadian Rhythms, Sleep Deprivation, and Human Performance

    Science.gov (United States)

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

    2014-01-01

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

  18. Entrainment of the Neurospora circadian clock

    NARCIS (Netherlands)

    Merrow, M; Boesl, C; Ricken, J; Messerschmitt, M; Goedel, M; Roenneberg, T

    2006-01-01

    Neurospora crassa has been systematically investigated for circadian entrainment behavior. Many aspects of synchronization can be investigated in this simple, cellular system, ranging from systematic entrainment and drivenness to masking. Clock gene expression during entrainment and entrainment

  19. Minimizing Residual Pressure within a Windowless Gas Target System - JENSA

    Science.gov (United States)

    Gomez, Orlando; Browne, Justin; Kontos, Antonios; Montes, Fernando; Jensa Collaboration

    2015-04-01

    Nuclear reactions between light gases and radioactive isotope beams are essential to address open questions in nuclear structure and astrophysics. Pure light gas targets are critical for the measurements of proton- and alpha-induced reactions. J _ et E _ xperiments in N _ uclear S _ tructure and A _ strophysics (JENSA) is the world's most dense (~ 1019 atoms/cm2) windowless gas target system. Most of the gas flow is localized; however, escaping gas creates a pressure gradient which degrades experimental measurements and contaminates the beam line. JENSA contains a differential pumping system to maintain a vacuum. The previous design configuration was not optimized for experiments (pressure measurements 70 cm downstream from the jet were ~ 10-3 torr; optimal is less than 10-4 torr). We have altered the current differential pumping system to minimize the residual pressure profile. Several configurations of two gas-receiving catchers were tested, and the most efficient ones identified using Enhanced Pirani and Cold Cathode gauges. We have determined the 30 mm outer and 20 mm inner gas-receiving cones minimize JENSA central chamber pressure to 200 millitorr at 16,000 torr of discharge pressure. Altering the tubing configuration has additionally lowered the pressure 70 cm downstream to 10-5 torr. The new residual pressure allows operation of JENSA with planned expansion of a recoil mass separator SECAR.

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

    Science.gov (United States)

    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.

  1. [Circadian markers and genes in bipolar disorder].

    Science.gov (United States)

    Yeim, S; Boudebesse, C; Etain, B; Belliviera, F

    2015-09-01

    Bipolar disorder is a severe and complex multifactorial disease, characterized by alternance of acute episodes of depression and mania/hypomania, interspaced by euthymic periods. The etiological determinants of bipolar disorder yet, are still poorly understood. For the last 30 years, chronobiology is an important field of investigation to better understand the pathophysiology of bipolar disorder. We conducted a review using Medline, ISI Database, EMBase, PsyInfo up to January 2015, using the following keywords combinations: "mood disorder", "bipolar disorder", "depression", "unipolar disorder", "major depressive disorder", "affective disorder", for psychiatric conditions; and "circadian rhythms", "circadian markers", "circadian gene", "clock gene", "melatonin" for circadian rhythms. The search critera was presence of word in any field of the article. Quantitative and qualitative circadian abnormalities are associated with bipolar disorders both during acute episodes and euthymic periods, suggesting that these altered circadian rhythms may represent biological trait markers of the disorder. These circadian dysfunctions were assessed by various validated tools including polysomnography, actigraphy, sleep diaries, chronotype assessments and blood melatonin/cortisol measures. Other altered endogenous circadian activities have also been reported in bipolar patients, such as hormones secretion, core body temperature or fibroblasts activity. Moreover, these markers were also altered in healthy relatives of bipolar patients, suggesting a degree of heritability. Several genetic association studies have also showed associations between multiple circadian genes and bipolar disorder, such as CLOCK, ARTNL1, GSK3β, PER3, NPAS2, NR1D1, TIMELESS, RORA, RORB, and CSNK1ε. Thus, these circadian gene variants may contribute to the genetic susceptibility of the disease. Furthermore, the study of the clock system may help to better understand some phenotypic aspects like the

  2. System Study: Residual Heat Removal 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-12-01

    This report presents an unreliability evaluation of the residual heat removal (RHR) system in two modes of operation (low-pressure injection in response to a large loss-of-coolant accident and post-trip shutdown-cooling) at 104 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing trends were identified in the RHR results. A highly statistically significant decreasing trend was observed for the RHR injection mode start-only unreliability. Statistically significant decreasing trends were observed for RHR shutdown cooling mode start-only unreliability and RHR shutdown cooling model 24-hour unreliability.

  3. Circadian rhythms of women with fibromyalgia

    Science.gov (United States)

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

    2001-01-01

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

  4. Control of Circadian Behavior by Transplanted Suprachiasmatic Nuclei.

    Science.gov (United States)

    1994-09-02

    Ihara NL (in press) The tau mutation destabilizes the circadian system of golden hamste,’s Fifth Sapporo Symposium on Biological Rhythms Hokkaido...Shimomura K and Ihara NL (in press) The tau mutation destabilizes the circadian system of golden hamsters Fifth Sapporo Symposium oh Biological Rhythms...Switzerland, April 5 University of Pisa, Dipartimento di Scienze del Comportamento Animale e dell’Uomo, invited lecture: "Circadian Organization in the

  5. Distribution of circadian clock-related proteins in the cephalic nervous system of the silkworm, Bombyx mori

    Czech Academy of Sciences Publication Activity Database

    Sehadová, Hana; Markova, E. P.; Sehnal, František; Takeda, M.

    2004-01-01

    Roč. 19, č. 6 (2004), s. 466-482 ISSN 0748-7304 Grant - others:JSPS(JP) 99L01205 Institutional research plan: CEZ:AV0Z5007907 Keywords : circadian rhythm * PER * CYC Subject RIV: ED - Physiology Impact factor: 2.979, year: 2004

  6. Daily circadian misalignment impairs human cognitive performance task-dependently.

    Science.gov (United States)

    Chellappa, Sarah L; Morris, Christopher J; Scheer, Frank A J L

    2018-02-14

    Shift work increases the risk for human errors, such that drowsiness due to shift work has contributed to major industrial disasters, including Space Shuttle Challenger, Chernobyl and Alaska Oil Spill disasters, with extraordinary socio-economical costs. Overnight operations pose a challenge because our circadian biology inhibits cognitive performance at night. Yet how the circadian system modulates cognition over multiple days under realistic shift work conditions remains to be established. Importantly, because task-specific cognitive brain regions show different 24-h circadian dynamics, we hypothesize that circadian misalignment impacts cognition task-dependently. Using a biologically-driven paradigm mimicking night shift work, with a randomized, cross-over design, we show that misalignment between the circadian pacemaker and behavioral/environmental cycles increases cognitive vulnerability on sustained attention, cognitive throughput, information processing and visual-motor performance over multiple days, compared to circadian alignment (day shifts). Circadian misalignment effects are task-dependent: while they acutely impair sustained attention with recovery after 3-days, they progressively hinder daily learning. Individuals felt sleepier during circadian misalignment, but they did not rate their performance as worse. Furthermore, circadian misalignment effects on sustained attention depended on prior sleep history. Collectively, daily circadian misalignment may provide an important biological framework for developing countermeasures against adverse cognitive effects in shift workers.

  7. Circadian Rhythm Sleep Disorders

    Directory of Open Access Journals (Sweden)

    Erhan Akinci

    2016-06-01

    Full Text Available The circadian rhythm sleep disorders define the clinical conditions where sleep and ndash;wake rhythm is disrupted despite optimum environmental and social conditions. They occur as a result of the changes in endogenous circadian hours or non-compatibility of environmental factors or social life with endogenous circadian rhythm. The sleep and ndash;wake rhythm is disrupted continuously or in repeating phases depending on lack of balance between internal and external cycles. This condition leads to functional impairments which cause insomnia, excessive sleepiness or both in people. Application of detailed sleep anamnesis and sleep diary with actigraphy record, if possible, will be sufficient for diagnosis. The treatment aims to align endogenous circadian rhythm with environmental conditions. The purpose of this article is to review pathology, clinical characteristics, diagnosis and treatment of circadian rhythm disorder. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 178-189

  8. Why and how do we model circadian rhythms?

    NARCIS (Netherlands)

    Beersma, DGM

    In our attempts to understand the circadian system, we unavoidably rely on abstractions. Instead of describing the behavior of the circadian system in all its complexity, we try to derive basic features from which we form a global concept on how the system works. Such a basic concept is a model of

  9. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    internal/physiological (endogenous) mechanism that drives them? Such questions have intrigued scientists for several decades and paved the way for the exploration of biological timing systems and their underlying mechanisms. Research on a wide variety of organisms has established that these rhythms are generated by.

  10. Evolution of circadian organization in vertebrates

    Directory of Open Access Journals (Sweden)

    M. Menaker

    1997-03-01

    Full Text Available Circadian organization means the way in which the entire circadian system above the cellular level is put together physically and the principles and rules that determine the interactions among its component parts which produce overt rhythms of physiology and behavior. Understanding this organization and its evolution is of practical importance as well as of basic interest. The first major problem that we face is the difficulty of making sense of the apparently great diversity that we observe in circadian organization of diverse vertebrates. Some of this diversity falls neatly into place along phylogenetic lines leading to firm generalizations: i in all vertebrates there is a "circadian axis" consisting of the retinas, the pineal gland and the suprachiasmatic nucleus (SCN, ii in many non-mammalian vertebrates of all classes (but not in any mammals the pineal gland is both a photoreceptor and a circadian oscillator, and iii in all non-mammalian vertebrates (but not in any mammals there are extraretinal (and extrapineal circadian photoreceptors. An interesting explanation of some of these facts, especially the differences between mammals and other vertebrates, can be constructed on the assumption that early in their evolution mammals passed through a "nocturnal bottleneck". On the other hand, a good deal of the diversity among the circadian systems of vertebrates does not fall neatly into place along phylogenetic lines. In the present review we will consider how we might better understand such "phylogenetically incoherent" diversity and what sorts of new information may help to further our understanding of the evolution of circadian organization in vertebrates

  11. Prediction of the protein components of a putative Calanus finmarchicus (Crustacea, Copepoda) circadian signaling system using a de novo assembled transcriptome.

    Science.gov (United States)

    Christie, Andrew E; Fontanilla, Tiana M; Nesbit, Katherine T; Lenz, Petra H

    2013-09-01

    Diel vertical migration and seasonal diapause are critical life history events for the copepod Calanus finmarchicus. While much is known about these behaviors phenomenologically, little is known about their molecular underpinnings. Recent studies in insects suggest that some circadian genes/proteins also contribute to the establishment of seasonal diapause. Thus, it is possible that in Calanus these distinct timing regimes share some genetic components. To begin to address this possibility, we used the well-established Drosophila melanogaster circadian system as a reference for mining clock transcripts from a 200,000+ sequence Calanus transcriptome; the proteins encoded by the identified transcripts were also deduced and characterized. Sequences encoding homologs of the Drosophila core clock proteins CLOCK, CYCLE, PERIOD and TIMELESS were identified, as was one encoding CRYPTOCHROME 2, a core clock protein in ancestral insect systems, but absent in Drosophila. Calanus transcripts encoding proteins known to modulate the Drosophila core clock were also identified and characterized, e.g. CLOCKWORK ORANGE, DOUBLETIME, SHAGGY and VRILLE. Alignment and structural analyses of the deduced Calanus proteins with their Drosophila counterparts revealed extensive sequence conservation, particularly in functional domains. Interestingly, reverse BLAST analyses of these sequences against all arthropod proteins typically revealed non-Drosophila isoforms to be most similar to the Calanus queries. This, in combination with the presence of both CRYPTOCHROME 1 (a clock input pathway protein) and CRYPTOCHROME 2 in Calanus, suggests that the organization of the copepod circadian system is an ancestral one, more similar to that of insects like Danaus plexippus than to that of Drosophila. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Physiological links of circadian clock and biological clock of aging.

    Science.gov (United States)

    Liu, Fang; Chang, Hung-Chun

    2017-07-01

    Circadian rhythms orchestrate biochemical and physiological processes in living organisms to respond the day/night cycle. In mammals, nearly all cells hold self-sustained circadian clocks meanwhile couple the intrinsic rhythms to systemic changes in a hierarchical manner. The suprachiasmatic nucleus (SCN) of the hypothalamus functions as the master pacemaker to initiate daily synchronization according to the photoperiod, in turn determines the phase of peripheral cellular clocks through a variety of signaling relays, including endocrine rhythms and metabolic cycles. With aging, circadian desynchrony occurs at the expense of peripheral metabolic pathologies and central neurodegenerative disorders with sleep symptoms, and genetic ablation of circadian genes in model organisms resembled the aging-related features. Notably, a number of studies have linked longevity nutrient sensing pathways in modulating circadian clocks. Therapeutic strategies that bridge the nutrient sensing pathways and circadian clock might be rational designs to defy aging.

  13. Multiscale Problems in Circadian Systems Biology: From Gene to Cell to Performance

    Science.gov (United States)

    2012-03-22

    the gametogenetic cycles in tropical hermatypic corals to the appropriate spawning season since photosynthate is their primary source of energy...scale phenomena in many other biological systems including the annual spawning of certain species of corals and; (vi) derivation of rigorous...the application domains of ecology, with the broad technical theme of understanding synchronized population-scale phenomena, such as coral spawning

  14. Circadian rhythm and menopause.

    Science.gov (United States)

    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.

  15. Circadian system functionality, hippocampal oxidative stress, and spatial memory in the APPswe/PS1dE9 transgenic model of Alzheimer disease: effects of melatonin or ramelteon.

    Science.gov (United States)

    Baño Otalora, Beatriz; Popovic, Natalija; Gambini, Juan; Popovic, Miroljub; Viña, José; Bonet-Costa, Vicent; Reiter, Russel J; Camello, Pedro Javier; Rol, Maria Ángeles; Madrid, Juan Antonio

    2012-08-01

    Alzheimer disease (AD) is a neurodegenerative disorder that primarily causes β-amyloid accumulation in the brain, resulting in cognitive and behavioral deficits. AD patients, however, also suffer from severe circadian rhythm disruptions, and the underlying causes are still not fully known. Patients with AD show reduced systemic melatonin levels. This may contribute to their symptoms, since melatonin is an effective chronobiotic and antioxidant with neuroprotective properties. Here, the authors critically assessed the effects of long-term melatonin treatment on circadian system function, hippocampal oxidative stress, and spatial memory performance in the APPswe/PS1 double transgenic (Tg) mouse model of AD. To test if melatonin MT1/MT2 receptor activation, alone, was involved, the authors chronically treated some mice with the selective MT1/MT2 receptor agonist ramelteon. The results indicate that many of the circadian and behavioral parameters measured, including oxidative stress markers, were not significantly affected in these AD mice. During the day, though, Tg controls (Tg-CON) showed significantly higher mean activity and body temperature (BT) than wild-type (WT) mice. Overall, BT rhythm amplitude was significantly lower in Tg than in WT mice. Although melatonin treatment had no effect, ramelteon significantly reduced the amplitude of the BT rhythm in Tg mice. Towards the end of the experiment, Tg mice treated with ramelteon (Tg-RAM) showed significantly higher circadian rhythm fragmentation than Tg-CON and reduced circadian BT rhythm strength. The free-running period (τ) for the BT and locomotor activity (LA) rhythms of Tg-CON was RAM compared with Tg-CON animals. These results suggest that not all aspects of the circadian system are affected in the APPswe/PS1 mice. Therefore, care should be taken when extending the results obtained in Tg mice to develop new therapies in humans. This study also revealed the complexity in the therapeutic actions of melatonin

  16. Interaction between circadian rhythms and stress

    Directory of Open Access Journals (Sweden)

    C.E. Koch

    2017-02-01

    Full Text Available Life on earth has adapted to the day-night cycle by evolution of internal, so-called circadian clocks that adjust behavior and physiology to the recurring changes in environmental conditions. In mammals, a master pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus receives environmental light information and synchronizes peripheral tissues and central non-SCN clocks to geophysical time. Regulatory systems such as the hypothalamus-pituitary-adrenal (HPA axis and the autonomic nervous system (ANS, both being important for the regulation of stress responses, receive strong circadian input. In this review, we summarize the interaction of circadian and stress systems and the resulting physiological and pathophysiological consequences. Finally, we critically discuss the relevance of rodent stress studies for humans, addressing complications of translational approaches and offering strategies to optimize animal studies from a chronobiological perspective.

  17. Breathing around the clock: an overview of the circadian pattern of respiration.

    Science.gov (United States)

    Mortola, Jacopo P

    2004-03-01

    This article reviews human and animal studies about the circadian patterns of physiological variables involved with the respiratory function. Some measures reflecting the mechanical properties of the lungs, such as functional residual capacity, forced expiratory volumes and airway resistance, change periodically with the time of the day. Also resting pulmonary ventilation (V(E)), tidal volume, and breathing rate follow circadian patterns. In humans, these patterns occur independently of the daily changes in activity, whereas, to some extent, they are linked to changes in the state of arousal. Differently, in some rodents, the circadian oscillations of the breathing pattern occur independently of the daily rhythms of either activity or state of arousal. Recent measurements of the breathing pattern for unlimited periods of time in undisturbed animals have indicated that the circadian changes occur in close temporal phase with those of oxygen consumption, carbon dioxide production, and body temperature. However, none of these variables can fully explain the circadian pattern of breathing, the origin of which remains unclear. Both in humans and in rats the V(E) responses to hypercapnia or hypoxia differ at various times of the day. In rats, the daily differences in V(E) responses are buffered by changes in metabolic rate, such that, unlike humans, the hyperventilation (defined as the increase in ventilation-metabolism ratio) remains constant throughout the 24 h. The presence of a biological clock is a major advantage in the adaptation to the environment, although it forces some variables to deviate periodically from their mean value. In humans, these deviations become apparent in conditions of hypoxia. Hence, a daily time-window exists in which the respiratory system is less capable of responding to challenges, a factor which may contribute to the findings that some cardio-respiratory symptoms and diseases peak at particular times of the day.

  18. Assessment of procurement systems for unutilized logging residues ...

    African Journals Online (AJOL)

    The results showed that coarse logging residues can be available as firewood in traditional utilization manner, but a thin material is left in the forest because of high collection and extraction costs. However, it was found that the increasing demand for forest biomass as a bioenergy resource encouraged the use of logging ...

  19. Influence of weeks of circadian misalignment on leptin levels

    Directory of Open Access Journals (Sweden)

    June Nguyen

    2009-12-01

    Full Text Available June Nguyen, Kenneth P Wright JrDepartment of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado, Boulder, CO, USAAbstract: The neurobiology of circadian, wakefulness–sleep, and feeding systems interact to influence energy homeostasis. Sleep and circadian disruptions are reported to be associated with increased risk of diabetes and obesity, yet the roles of energy balance hormones in these associations are largely unknown. Therefore, in the current study we aimed to assess the influence of several weeks of circadian misalignment (sleep and wakefulness occurring at an inappropriate biological time on the anorexigenic adipocyte hormone leptin. We utilized data from a previous study designed to assess physiological and cognitive consequences of changes in day length and light exposure as may occur during space flight, including exploration class space missions and exposure to the Martian Sol (day length. We hypothesized that circadian misalignment during an exploration class spaceflight simulation would reduce leptin levels. Following a three-week ~8 hours per night home sleep schedule, 14 healthy participants lived in the laboratory for more than one month. After baseline data collection, participants were scheduled to either 24.0 or 24.6 hours of wakefulness–sleep schedules for 25 days. Changes in the phase of the circadian melatonin rhythm, sleep, and leptin levels were assessed. Half of participants analyzed exhibited circadian misalignment with an average change in phase angle from baseline of ~4 hours and these participants showed reduced leptin levels, sleep latency, stage 2 and total sleep time (7.3 to 6.6 hours and increased wakefulness after sleep onset (all P < 0.05. The control group remained synchronized and showed significant increases in sleep latency and leptin levels. Our findings indicate that weeks of circadian misalignment, such as that which occurs in circadian sleep disorders, alters leptin

  20. Physiological effects of light on the human circadian pacemaker

    Science.gov (United States)

    Shanahan, T. L.; Czeisler, C. A.

    2000-01-01

    The physiology of the human circadian pacemaker and its influence and on the daily organization of sleep, endocrine and behavioral processes is an emerging interest in science and medicine. Understanding the development, organization and fundamental properties underlying the circadian timing system may provide insight for the application of circadian principles to the practice of clinical medicine, both diagnostically (interpretation of certain clinical tests are dependent on time of day) and therapeutically (certain pharmacological responses vary with the time of day). The light-dark cycle is the most powerful external influence acting upon the human circadian pacemaker. It has been shown that timed exposure to light can both synchronize and reset the phase of the circadian pacemaker in a predictable manner. The emergence of detectable circadian rhythmicity in the neonatal period is under investigation (as described elsewhere in this issue). Therefore, the pattern of light exposure provided in the neonatal intensive care setting has implications. One recent study identified differences in both amount of sleep time and weight gain in infants maintained in a neonatal intensive care environment that controlled the light-dark cycle. Unfortunately, neither circadian phase nor the time of day has been considered in most clinical investigations. Further studies with knowledge of principles characterizing the human circadian timing system, which governs a wide array of physiological processes, are required to integrate these findings with the practice of clinical medicine.

  1. Constant-coefficient FIR filters based on residue number system arithmetic

    Directory of Open Access Journals (Sweden)

    Stamenković Negovan

    2012-01-01

    Full Text Available In this paper, the design of a Finite Impulse Response (FIR filter based on the residue number system (RNS is presented. We chose to implement it in the (RNS, because the RNS offers high speed and low power dissipation. This architecture is based on the single RNS multiplier-accumulator (MAC unit. The three moduli set {2n+1,2n,2n-1}, which avoids 2n+1 modulus, is used to design FIR filter. A numerical example illustrates the principles of residue encoding, residue arithmetic, and residue decoding for FIR filters.

  2. Suitability of the charm HVS and a microbiological multiplate system for detection of residues in raw milk at EU maximum residue levels

    NARCIS (Netherlands)

    Nouws, J.F.M.; Egmond, van H.; Loeffen, G.; Schouten, J.; Keukens, H.; Smulders, I.; Stegeman, H.

    1999-01-01

    In this paper we assessed the suitability of the Charm HVS and a newly developed microbiological multiplate system as post-screening tests to confirm the presence of residues in raw milk at or near the maximum permissible residue level (MRL). The multiplate system is composed of Bacillus

  3. The Molecular Circadian Clock and Alcohol-Induced Liver Injury

    Directory of Open Access Journals (Sweden)

    Uduak S. Udoh

    2015-10-01

    Full Text Available Emerging evidence from both experimental animal studies and clinical human investigations demonstrates strong connections among circadian processes, alcohol use, and alcohol-induced tissue injury. Components of the circadian clock have been shown to influence the pathophysiological effects of alcohol. Conversely, alcohol may alter the expression of circadian clock genes and the rhythmic behavioral and metabolic processes they regulate. Therefore, we propose that alcohol-mediated disruption in circadian rhythms likely underpins many adverse health effects of alcohol that cut across multiple organ systems. In this review, we provide an overview of the circadian clock mechanism and showcase results from new studies in the alcohol field implicating the circadian clock as a key target of alcohol action and toxicity in the liver. We discuss various molecular events through which alcohol may work to negatively impact circadian clock-mediated processes in the liver, and contribute to tissue pathology. Illuminating the mechanistic connections between the circadian clock and alcohol will be critical to the development of new preventative and pharmacological treatments for alcohol use disorders and alcohol-mediated organ diseases.

  4. Diurnal Oscillations of Soybean Circadian Clock and Drought Responsive Genes

    Science.gov (United States)

    Marcolino-Gomes, Juliana; Rodrigues, Fabiana Aparecida; Fuganti-Pagliarini, Renata; Bendix, Claire; Nakayama, Thiago Jonas; Celaya, Brandon; Molinari, Hugo Bruno Correa; de Oliveira, Maria Cristina Neves; Harmon, Frank G.; Nepomuceno, Alexandre

    2014-01-01

    Rhythms produced by the endogenous circadian clock play a critical role in allowing plants to respond and adapt to the environment. While there is a well-established regulatory link between the circadian clock and responses to abiotic stress in model plants, little is known of the circadian system in crop species like soybean. This study examines how drought impacts diurnal oscillation of both drought responsive and circadian clock genes in soybean. Drought stress induced marked changes in gene expression of several circadian clock-like components, such as LCL1-, GmELF4- and PRR-like genes, which had reduced expression in stressed plants. The same conditions produced a phase advance of expression for the GmTOC1-like, GmLUX-like and GmPRR7-like genes. Similarly, the rhythmic expression pattern of the soybean drought-responsive genes DREB-, bZIP-, GOLS-, RAB18- and Remorin-like changed significantly after plant exposure to drought. In silico analysis of promoter regions of these genes revealed the presence of cis-elements associated both with stress and circadian clock regulation. Furthermore, some soybean genes with upstream ABRE elements were responsive to abscisic acid treatment. Our results indicate that some connection between the drought response and the circadian clock may exist in soybean since (i) drought stress affects gene expression of circadian clock components and (ii) several stress responsive genes display diurnal oscillation in soybeans. PMID:24475115

  5. Diurnal oscillations of soybean circadian clock and drought responsive genes.

    Directory of Open Access Journals (Sweden)

    Juliana Marcolino-Gomes

    Full Text Available Rhythms produced by the endogenous circadian clock play a critical role in allowing plants to respond and adapt to the environment. While there is a well-established regulatory link between the circadian clock and responses to abiotic stress in model plants, little is known of the circadian system in crop species like soybean. This study examines how drought impacts diurnal oscillation of both drought responsive and circadian clock genes in soybean. Drought stress induced marked changes in gene expression of several circadian clock-like components, such as LCL1-, GmELF4- and PRR-like genes, which had reduced expression in stressed plants. The same conditions produced a phase advance of expression for the GmTOC1-like, GmLUX-like and GmPRR7-like genes. Similarly, the rhythmic expression pattern of the soybean drought-responsive genes DREB-, bZIP-, GOLS-, RAB18- and Remorin-like changed significantly after plant exposure to drought. In silico analysis of promoter regions of these genes revealed the presence of cis-elements associated both with stress and circadian clock regulation. Furthermore, some soybean genes with upstream ABRE elements were responsive to abscisic acid treatment. Our results indicate that some connection between the drought response and the circadian clock may exist in soybean since (i drought stress affects gene expression of circadian clock components and (ii several stress responsive genes display diurnal oscillation in soybeans.

  6. Postoperative circadian disturbances

    DEFF Research Database (Denmark)

    Gögenur, Ismail

    2010-01-01

    parameters, and if pharmacological administration of chronobiotics could improve postoperative recovery. Circadian rhythm disturbances were found in all the examined endogenous rhythms. A delay was found in the endogenous rhythm of plasma melatonin and excretion of the metabolite of melatonin (AMT6s...... in patients with lower than median pain levels for a three days period after laparoscopic cholecystectomy. In the series of studies included in this thesis we have systematically shown that circadian disturbances are found in the secretion of hormones, the sleep-wake cycle, core body temperature rhythm...

  7. Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences, and Countermeasures

    Science.gov (United States)

    Skene, Debra J.; Arendt, Josephine; Cade, Janet E.; Grant, Peter J.; Hardie, Laura J.

    2016-01-01

    Circadian (∼24-hour) timing systems pervade all kingdoms of life and temporally optimize behavior and physiology in humans. Relatively recent changes to our environments, such as the introduction of artificial lighting, can disorganize the circadian system, from the level of the molecular clocks that regulate the timing of cellular activities to the level of synchronization between our daily cycles of behavior and the solar day. Sleep/wake cycles are intertwined with the circadian system, and global trends indicate that these, too, are increasingly subject to disruption. A large proportion of the world's population is at increased risk of environmentally driven circadian rhythm and sleep disruption, and a minority of individuals are also genetically predisposed to circadian misalignment and sleep disorders. The consequences of disruption to the circadian system and sleep are profound and include myriad metabolic ramifications, some of which may be compounded by adverse effects on dietary choices. If not addressed, the deleterious effects of such disruption will continue to cause widespread health problems; therefore, implementation of the numerous behavioral and pharmaceutical interventions that can help restore circadian system alignment and enhance sleep will be important. PMID:27763782

  8. Sleep Deprivation and Circadian Disruption: Stress, Allostasis, and Allostatic Load.

    Science.gov (United States)

    McEwen, Bruce S; Karatsoreos, Ilia N

    2015-03-01

    Sleep has important homeostatic functions, and circadian rhythms organize physiology and behavior on a daily basis to insure optimal function. Sleep deprivation and circadian disruption can be stressors, enhancers of other stressors that have consequences for the brain and many body systems. Whether the origins of circadian disruption and sleep disruption and deprivation are from anxiety, depression, shift work, long-distance air travel, or a hectic lifestyle, there are consequences that impair brain functions and contribute to the cumulative wear and tear on body systems caused by too much stress and/or inefficient management of the systems that promote adaptation. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Residue-based Coordinated Selection and Parameter Design of Multiple Power System Stabilizers (PSSs)

    DEFF Research Database (Denmark)

    Su, Chi; Hu, Weihao; Fang, Jiakun

    2013-01-01

    Residue method is a commonly used approach to design the parameters of a power system stabilizer (PSS). In this paper, a residue identification method is adopted to obtain the system residues for different input-output pairs, using the system identification toolbox in MATLAB with the measurement...... as the test system is built in DIgSIELNT PowerFactory 14.0, in which the proposed coordination method is validated by time domain simulations and modal analysis....... data from time domain simulations. Then a coordinated approach for multiple PSS selection and parameter design based on residue method is proposed and realized in MATLAB m-files. Particle swarm optimization (PSO) is adopted in the coordination process. The IEEE 39-bus New England system model...

  10. Long-term Levodopa Treatment Accelerates the Circadian Rhythm Dysfunction in a 6-hydroxydopamine Rat Model of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Si-Yue Li

    2017-01-01

    Conclusions: In the circadian system of advanced PD rat models, circadian dysfunction is not only contributed by the degeneration of the disease itself but also long-term L-DOPA therapy may further aggravate it.

  11. Neural Mechanisms of Circadian Regulation of Natural and Drug Reward

    Directory of Open Access Journals (Sweden)

    Lauren M. DePoy

    2017-01-01

    Full Text Available Circadian rhythms are endogenously generated near 24-hour variations of physiological and behavioral functions. In humans, disruptions to the circadian system are associated with negative health outcomes, including metabolic, immune, and psychiatric diseases, such as addiction. Animal models suggest bidirectional relationships between the circadian system and drugs of abuse, whereby desynchrony, misalignment, or disruption may promote vulnerability to drug use and the transition to addiction, while exposure to drugs of abuse may entrain, disrupt, or perturb the circadian timing system. Recent evidence suggests natural (i.e., food and drug rewards may influence overlapping neural circuitry, and the circadian system may modulate the physiological and behavioral responses to these stimuli. Environmental disruptions, such as shifting schedules or shorter/longer days, influence food and drug intake, and certain mutations of circadian genes that control cellular rhythms are associated with altered behavioral reward. We highlight the more recent findings associating circadian rhythms to reward function, linking environmental and genetic evidence to natural and drug reward and related neural circuitry.

  12. Unique Fiber Optic Sensor System for Residual Stress Measurement on Graphite Composites

    National Research Council Canada - National Science Library

    Bullock, D

    1995-01-01

    .... Measurement of this strain through the thickness of a composite is not a trivial task. Foster-Miller has developed the basis for a residual strain measurement system utilizing embedded fiber optic Bragg grating technology...

  13. Biological Clocks & Circadian Rhythms

    Science.gov (United States)

    Robertson, Laura; Jones, M. Gail

    2009-01-01

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

  14. Circadian Patterns in Twitter

    NARCIS (Netherlands)

    ten Thij, M.C.; Kampstra, P.; Bhulai, S.; Laux, F.; Pardalos, P.M.; Crolotte, A.

    2014-01-01

    In this paper, we study activity on the microblogging platform Twitter. We analyse two separate aspects of activity on Twitter. First, we analyse the daily and weekly number of posts, through which we find clear circadian (daily) patterns emerging in the use of Twitter for multiple languages. We see

  15. Calculating residual flows through a multiple-inlet system: the conundrum of the tidal period

    Science.gov (United States)

    Duran-Matute, Matias; Gerkema, Theo

    2015-11-01

    The concept of residual, i.e., tidally-averaged, flows through a multiple inlet system is reappraised. The evaluation of the residual through-flow depends on the time interval over which is integrated, in other words, on how one defines the tidal period. It is demonstrated that this definition is ambiguous and that different definitions (based on, e.g., high waters, slack tides, etc.) yield very different results for the residual, also in terms of their long-term statistical properties (median and standard deviation). A basin-wide applicable method of defining the tidal period, in terms of enclosed water volume, is analyzed. We compare the different methods on the basis of high-resolution model results for the Western Dutch Wadden Sea. The multitude of tidal constituents together with wind variability creates broad distributions for the residuals, with standard deviations much larger than the mean or median residual flows.

  16. Cellular Clocks : Coupled Circadian Dispatch and Cell Division Cycles

    NARCIS (Netherlands)

    Merrow, Martha; Roenneberg, Till

    2004-01-01

    Gating of cell division by the circadian clock is well known, yet its mechanism is little understood. Genetically tractable model systems have led to new hypotheses and questions concerning the coupling of these two cellular cycles.

  17. Circadian rhythm and sleep influences on digestive physiology and disorders

    OpenAIRE

    Vaughn, Bradley; Rotolo,Sean; Roth,Heidi

    2014-01-01

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

  18. On conditional residual lifetime and conditional inactivity time of k-out-of-n systems

    International Nuclear Information System (INIS)

    Tavangar, Mahdi; Bairamov, Ismihan

    2015-01-01

    In designing structures of technical systems, the reliability engineers often deal with the reliability analysis of coherent systems. Coherent system has monotone structure function and all components of the system are relevant. This paper considers some particular models of coherent systems having identical components with independent lifetimes. The main purpose of the paper is to study conditional residual lifetime of coherent system, given that at a fixed time certain number of components have failed but still there are some functioning components. Different aging and stochastic properties of variables connected with the conditional residual lifetimes of the coherent systems are obtained. An expression for the parent distribution in terms of conditional mean residual lifetime is provided. The similar result is obtained for the conditional mean inactivity time of the failed components of coherent system. The conditional mean inactivity time of failed components presents an interest in many engineering applications where the reliability of system structure is important for designing and constructing of systems. Some illustrative examples with given particular distributions are also presented. - Highlights: • Comparisons of conditional residual lifetime of k-out-of-n systems are derived. • The behavior of the coherent system is explored for IHR distributions. • The parent distribution is expressed in terms of conditional MRL and MIT. • Some illustrative examples are given to clarify the results of the paper.

  19. Reciprocal interactions between sleep, circadian rhythms and Alzheimer's disease: focus on the role of hypocretin and melatonin

    NARCIS (Netherlands)

    Slats, D.; Claassen, J.A.H.R.; Verbeek, M.M.; Overeem, S.

    2013-01-01

    AD, sleep and circadian rhythm physiology display an intricate relationship. On the one hand, AD pathology leads to sleep and circadian disturbances, with a clear negative influence on quality of life. On the other hand, there is increasing evidence that both sleep and circadian regulating systems

  20. Circadian adaptations to meal timing: Neuroendocrine mechanisms

    Directory of Open Access Journals (Sweden)

    Danica F Patton

    2013-10-01

    Full Text Available Circadian rhythms of behavior and physiology are generated by central and peripheral circadian oscillators entrained by periodic environmental or physiological stimuli. A master circadian pacemaker in the hypothalamic suprachiasmatic nucleus is directly entrained by daily light-dark cycles, and coordinates the timing of other oscillators by direct and indirect neural, hormonal and behavioral outputs. The daily rhythm of food intake provides stimuli that entrain most peripheral and central oscillators, some of which can drive a daily rhythm of food anticipatory activity if food is restricted to one daily mealtime. The location of food-entrainable oscillators (FEOs that drive food anticipatory rhythms, and the food-related stimuli that entrain these oscillators, remain to be clarified. Here, we critically examine the role of peripheral metabolic hormones as potential internal entrainment stimuli or outputs for FEOs controlling food anticipatory rhythms in rats and mice. Hormones for which data are available include corticosterone, ghrelin, leptin, insulin, glucagon, and glucagon-like peptide 1. All of these hormones exhibit daily rhythms of synthesis and secretion that are synchronized by meal timing. There is some evidence that ghrelin and leptin modulate the expression of food anticipatory rhythms, but none of the hormones examined so far are necessary for entrainment. Ghrelin and leptin likely modulate food-entrained rhythms by actions in hypothalamic circuits utilizing melanocortin and orexin signaling, although again food-entrained behavioral rhythms can persist in lesion and gene knockout models in which these systems are disabled. Actions of these hormones on circadian oscillators in central reward circuits remain to be evaluated. Food-entrained activity rhythms are likely mediated by a distributed system of circadian oscillators sensitive to multiple feeding related inputs. Metabolic hormones appear to play a modulatory role within this

  1. Circadian adaptations to meal timing: neuroendocrine mechanisms.

    Science.gov (United States)

    Patton, Danica F; Mistlberger, Ralph E

    2013-10-14

    Circadian rhythms of behavior and physiology are generated by central and peripheral circadian oscillators entrained by periodic environmental or physiological stimuli. A master circadian pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) is directly entrained by daily light-dark (LD) cycles, and coordinates the timing of other oscillators by direct and indirect neural, hormonal and behavioral outputs. The daily rhythm of food intake provides stimuli that entrain most peripheral and central oscillators, some of which can drive a daily rhythm of food anticipatory activity if food is restricted to one daily mealtime. The location of food-entrainable oscillators (FEOs) that drive food anticipatory rhythms, and the food-related stimuli that entrain these oscillators, remain to be clarified. Here, we critically examine the role of peripheral metabolic hormones as potential internal entrainment stimuli or outputs for FEOs controlling food anticipatory rhythms in rats and mice. Hormones for which data are available include corticosterone, ghrelin, leptin, insulin, glucagon, and glucagon-like peptide 1. All of these hormones exhibit daily rhythms of synthesis and secretion that are synchronized by meal timing. There is some evidence that ghrelin and leptin modulate the expression of food anticipatory rhythms, but none of the hormones examined so far are necessary for entrainment. Ghrelin and leptin likely modulate food-entrained rhythms by actions in hypothalamic circuits utilizing melanocortin and orexin signaling, although again food-entrained behavioral rhythms can persist in lesion and gene knockout models in which these systems are disabled. Actions of these hormones on circadian oscillators in central reward circuits remain to be evaluated. Food-entrained activity rhythms are likely mediated by a distributed system of circadian oscillators sensitive to multiple feeding related inputs. Metabolic hormones appear to play a modulatory role within this system.

  2. A Residual Approach for Balanced Truncation Model Reduction (BTMR of Compartmental Systems

    Directory of Open Access Journals (Sweden)

    William La Cruz

    2014-05-01

    Full Text Available This paper presents a residual approach of the square root balanced truncation algorithm for model order reduction of continuous, linear and time-invariante compartmental systems. Specifically, the new approach uses a residual method to approximate the controllability and observability gramians, whose resolution is an essential step of the square root balanced truncation algorithm, that requires a great computational cost. Numerical experiences are included to highlight the efficacy of the proposed approach.

  3. Circadian clock-mediated regulation of blood pressure.

    Science.gov (United States)

    Douma, Lauren G; Gumz, Michelle L

    2017-12-02

    Most bodily functions vary over the course of a 24h day. Circadian rhythms in body temperature, sleep-wake cycles, metabolism, and blood pressure (BP) are just a few examples. These circadian rhythms are controlled by the central clock in the suprachiasmatic nucleus (SCN) of the hypothalamus and peripheral clocks located throughout the body. Light and food cues entrain these clocks to the time of day and this synchronicity contributes to the regulation of a variety of physiological processes with effects on overall health. The kidney, brain, nervous system, vasculature, and heart have been identified through the use of mouse models and clinical trials as peripheral clock regulators of BP. The dysregulation of this circadian pattern of BP, with or without hypertension, is associated with increased risk for cardiovascular disease. The mechanism of this dysregulation is unknown and is a growing area of research. In this review, we highlight research of human and mouse circadian models that has provided insight into the roles of these molecular clocks and their effects on physiological functions. Additional tissue-specific studies of the molecular clock mechanism are needed, as well as clinical studies including more diverse populations (different races, female patients, etc.), which will be critical to fully understand the mechanism of circadian regulation of BP. Understanding how these molecular clocks regulate the circadian rhythm of BP is critical in the treatment of circadian BP dysregulation and hypertension. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Photoperiodic plasticity in circadian clock neurons in insects

    Directory of Open Access Journals (Sweden)

    Sakiko eShiga

    2013-08-01

    Full Text Available Since Bünning’s observation of circadian rhythms and photoperiodism in the runner bean Phaseolus multiflorus in 1936, many studies have shown that photoperiodism is based on the circadian clock system. In insects, involvement of circadian clock genes or neurons has been recently shown in the photoperiodic control of developmental arrests, diapause. Based on molecular and neuronal studies in Drosophila melanogaster, photoperiodic changes have been reported for expression patterns of the circadian clock genes, subcellular distribution of clock proteins, fiber distribution, or the number of plausible clock neurons in different species. Photoperiod sets peaks of per or tim mRNA abundance at lights-off in Sarcophaga crassipalpis, Chymomyza costata and Protophormia terraenovae. Abundance of per and Clock mRNA changes by photoperiod in Pyrrhocoris apterus. Subcellular Per distribution in circadian clock neurons changes with photoperiod in P. terraenovae. Although photoperiodism is not known in Leucophaea maderae, under longer day length, more stomata and longer commissural fibers of circadian clock neurons have been found. These plastic changes in the circadian clock neurons could be an important constituent for photoperiodic clock mechanisms to integrate repetitive photoperiodic information and produce different outputs based on day length.

  5. Circadian clock and vascular disease.

    OpenAIRE

    Takeda, Norihiko; Maemura, Koji

    2010-01-01

    Cardiovascular functions, including blood pressure and vascular functions, show diurnal oscillation. Circadian variations have been clearly shown in the occurrence of cardiovascular events such as acute myocardial infarction. Circadian rhythm strongly influences human biology and pathology. The identification and characterization of mammalian clock genes revealed that they are expressed almost everywhere throughout the body in a circadian manner. In contrast to the central clock in the suprac...

  6. Circadian misalignment, reward-related brain function, and adolescent alcohol involvement.

    Science.gov (United States)

    Hasler, Brant P; Clark, Duncan B

    2013-04-01

    Developmental changes in sleep and circadian rhythms that occur during adolescence may contribute to reward-related brain dysfunction, and consequently increase the risk of alcohol use disorders (AUDs). This review (i) describes marked changes in circadian rhythms, reward-related behavior and brain function, and alcohol involvement that occur during adolescence, (ii) offers evidence that these parallel developmental changes are associated, and (iii) posits a conceptual model by which misalignment between sleep-wake timing and endogenous circadian timing may increase the risk of adolescent AUDs by altering reward-related brain function. The timing of sleep shifts later throughout adolescence, in part due to developmental changes in endogenous circadian rhythms, which tend to become more delayed. This tendency for delayed sleep and circadian rhythms is at odds with early school start times during secondary education, leading to misalignment between many adolescents' sleep-wake schedules and their internal circadian timing. Circadian misalignment is associated with increased alcohol use and other risk-taking behaviors, as well as sleep loss and sleep disturbance. Growing evidence indicates that circadian rhythms modulate the reward system, suggesting that circadian misalignment may impact adolescent alcohol involvement by altering reward-related brain function. Neurocognitive function is also subject to sleep and circadian influence, and thus circadian misalignment may also impair inhibitory control and other cognitive processes relevant to alcohol use. Specifically, circadian misalignment may further exacerbate the cortical-subcortical imbalance within the reward circuit, an imbalance thought to explain increased risk-taking and sensation-seeking during adolescence. Adolescent alcohol use is highly contextualized, however, and thus studies testing this model will also need to consider factors that may influence both circadian misalignment and alcohol use. This review

  7. Circadian Regulation of Synaptic Plasticity

    Directory of Open Access Journals (Sweden)

    Marcos G. Frank

    2016-07-01

    Full Text Available Circadian rhythms refer to oscillations in biological processes with a period of approximately 24 h. In addition to the sleep/wake cycle, there are circadian rhythms in metabolism, body temperature, hormone output, organ function and gene expression. There is also evidence of circadian rhythms in synaptic plasticity, in some cases driven by a master central clock and in other cases by peripheral clocks. In this article, I review the evidence for circadian influences on synaptic plasticity. I also discuss ways to disentangle the effects of brain state and rhythms on synaptic plasticity.

  8. Thermoregulation is impaired in an environment without circadian time cues

    Science.gov (United States)

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

    1978-01-01

    Thirteen adult male squirrel monkeys were restrained to a metabolism chair for periods of two or more weeks within an isolation chamber having controlled environmental lighting and ambient temperature. The monkeys were subjected to mild 6-hour cold exposures at all circadian phases of the day. It was found that a prominent circadian rhythm in body temperature, regulated against mild cold exposure, was present in those monkeys synchronized in a 24-hour light-dark cycle. Cold exposures were found to produce decreased core body temperatures when the circadian rhythms were free running or when environmental time indicators were not present. It is concluded that the thermoregulating system depends on the internal synchronization of the circadian time-keeping system.

  9. Construction of a risk assessment system for chemical residues in agricultural products.

    Science.gov (United States)

    Choi, Shinai; Hong, Jiyeon; Lee, Dayeon; Paik, Minkyoung

    2014-01-01

    Continuous monitoring of chemical residues in agricultural and food products has been performed by various government bodies in South Korea. These bodies have made attempts to systematically manage this information by creating a monitoring database system as well as a system based on these data with which to assess the health risk of chemical residues in agricultural products. Meanwhile, a database system is being constructed consisting of information about monitoring and, following this, a demand for convenience has led to the need for an evaluation tool to be constructed with the data processing system. Also, in order to create a systematic and effective tool for the risk assessment of chemical residues in foods and agricultural products, various evaluation models are being developed, both domestically and abroad. Overseas, systems such as Dietary Exposure Evaluation Model: Food Commodity Intake Database and Cumulative and Aggregate Risk Evaluation System are being used; these use the US Environmental Protection Agency as a focus, while the EU has developed Pesticide Residue Intake Model for assessments of pesticide exposure through food intake. Following this, the National Academy of Agricultural Science (NAAS) created the Agricultural Products Risk Assessment System (APRAS) which supports the use and storage of monitoring information and risk assessments. APRAS efficiently manages the monitoring data produced by NAAS and creates an extraction feature included in the database system. Also, the database system in APRAS consists of a monitoring database system held by the NAAS and food consumption database system. Food consumption data is based on Korea National Health and Nutrition Examination Survey. This system is aimed at exposure and risk assessments for chemical residues in agricultural products with regards to different exposure scenarios.

  10. A method to evaluate residual phase error for polar formatted synthetic aperture radar systems

    Science.gov (United States)

    Musgrove, Cameron; Naething, Richard

    2013-05-01

    Synthetic aperture radar systems that use the polar format algorithm are subject to a focused scene size limit inherent to the polar format algorithm. The classic focused scene size limit is determined from the dominant residual range phase error term. Given the many sources of phase error in a synthetic aperture radar, a system designer is interested in how much phase error results from the assumptions made with the polar format algorithm. Autofocus algorithms have limits to the amount and type of phase error that can be corrected. Current methods correct only one or a few terms of the residual phase error. A system designer needs to be able to evaluate the contribution of the residual or uncorrected phase error terms to determine the new focused scene size limit. This paper describes a method to estimate the complete residual phase error, not just one or a few of the dominant residual terms. This method is demonstrated with polar format image formation, but is equally applicable to other image formation algorithms. A benefit for the system designer is that additional correction terms can be added or deleted from the analysis as necessary to evaluate the resulting effect upon image quality.

  11. Residual tree damage during selection cuts using two skidding systems in the Missouri Ozarks

    Science.gov (United States)

    Robert L. Ficklin; John P. Dwyer; Bruce E. Cutter; Tom Draper

    1997-01-01

    Today, there is an interest in using alternative silvicultural systems like selection and two-aged management, because the public finds these systems more acceptable than clearcutting. However, repeated entries into forest stands to remove timber increase the risk of residual stand damage. Harvest techniques are desirable that (1) reduce the risk of stand damage and (2...

  12. Residual generation with unknown input observer for linear systems in the presence of unmatched uncertainties

    International Nuclear Information System (INIS)

    Bagherpour, Esmaeel A.; HairiTazdi, Mohammad Reza; Mahjoob, Mohammad

    2014-01-01

    In this paper, we deal with residual vector generation for fault detection problems in linear systems via unknown input observer (UIO) when the so-called observer matching condition is not satisfied. Based on the relative degree between unknown input and output, a vector of the auxiliary output is introduced so that the observer matching condition is satisfied with respect to the vector. Auxiliary outputs are related to the derivatives of measured signals. However, differentiation leads to excessive amplification of measurement noise. A dynamically equivalent configuration of linear systems is developed using successive integrations to avoid differentiation. As such, auxiliary outputs are constructed without differentiation. Then, the equivalent dynamic system and its corresponding auxiliary outputs are used to generate the residual vector via an exponentially converging UIO. Fault detection in the generated residual vector is also investigated. Finally, the effectiveness of the proposed method is shown via numerical simulation.

  13. Circadian disorganization alters intestinal microbiota.

    Science.gov (United States)

    Voigt, Robin M; Forsyth, Christopher B; Green, Stefan J; Mutlu, Ece; Engen, Phillip; Vitaterna, Martha H; Turek, Fred W; Keshavarzian, Ali

    2014-01-01

    Intestinal dysbiosis and circadian rhythm disruption are associated with similar diseases including obesity, metabolic syndrome, and inflammatory bowel disease. Despite the overlap, the potential relationship between circadian disorganization and dysbiosis is unknown; thus, in the present study, a model of chronic circadian disruption was used to determine the impact on the intestinal microbiome. Male C57BL/6J mice underwent once weekly phase reversals of the light:dark cycle (i.e., circadian rhythm disrupted mice) to determine the impact of circadian rhythm disruption on the intestinal microbiome and were fed either standard chow or a high-fat, high-sugar diet to determine how diet influences circadian disruption-induced effects on the microbiome. Weekly phase reversals of the light:dark (LD) cycle did not alter the microbiome in mice fed standard chow; however, mice fed a high-fat, high-sugar diet in conjunction with phase shifts in the light:dark cycle had significantly altered microbiota. While it is yet to be established if some of the adverse effects associated with circadian disorganization in humans (e.g., shift workers, travelers moving across time zones, and in individuals with social jet lag) are mediated by dysbiosis, the current study demonstrates that circadian disorganization can impact the intestinal microbiota which may have implications for inflammatory diseases.

  14. Circadian Clocks : Running on Redox

    NARCIS (Netherlands)

    Merrow, Martha; Roenneberg, Till

    2001-01-01

    The circadian clock in all organisms is so intimately linked to light reception that it appears as if evolution has simply wired a timer into the mechanism that processes photic information. Several recent studies have provided new insights into the role of light input pathways in the circadian

  15. The neurobiology of circadian rhythms

    NARCIS (Netherlands)

    Van der Zee, Eddy A.; Boersma, Gretha J.; Hut, Roelof A.

    2009-01-01

    Purpose of review There is growing awareness of the importance of circadian rhythmicity in various research fields. Exciting developments are ongoing in the field of circadian neurobiology linked to sleep, food intake, and memory. With the current knowledge of critical clock genes' (genes found to

  16. Circadian rhythms in microalgae production

    NARCIS (Netherlands)

    Winter, de L.

    2015-01-01

    Abstract Thesis: Circadian rhythms in microalgae production

    Lenneke de Winter

    The sun imposes a daily cycle of light and dark on nearly all organisms. The circadian clock evolved to help organisms program their activities at an appropriate time during this daily

  17. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Junli Gou

    2009-01-01

    Full Text Available A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS, which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (SCPRHRS, the transient behaviors of the PRHRS as well as the effects of the height difference between the steam generator and the heat exchanger and the heat transfer area of the heat exchanger are studied in detail. Through the calculation analysis, it is found that the calculated parameter variation trends are reasonable. The higher height difference between the steam generator and the residual heat exchanger and the larger heat transfer area of the residual heat exchanger are favorable to the passive residual heat removal system.

  18. Crop residues as raw materials for biorefinery systems - A LCA case study

    International Nuclear Information System (INIS)

    Cherubini, Francesco; Ulgiati, Sergio

    2010-01-01

    Our strong dependence on fossil fuels results from the intensive use and consumption of petroleum derivatives which, combined with diminishing oil resources, causes environmental and political concerns. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. This paper focuses on a biorefinery concept which produces bioethanol, bioenergy and biochemicals from two types of agricultural residues, corn stover and wheat straw. These biorefinery systems are investigated using a Life Cycle Assessment (LCA) approach, which takes into account all the input and output flows occurring along the production chain. This approach can be applied to almost all the other patterns that convert lignocellulosic residues into bioenergy and biochemicals. The analysis elaborates on land use change aspects, i.e. the effects of crop residue removal (like decrease in grain yields, change in soil N 2 O emissions and decrease of soil organic carbon). The biorefinery systems are compared with the respective fossil reference systems producing the same amount of products/services from fossils instead of biomass. Since climate change mitigation and energy security are the two most important driving forces for biorefinery development, the assessment focuses on greenhouse gas (GHG) emissions and cumulative primary energy demand, but other environmental categories are evaluated as well. Results show that the use of crop residues in a biorefinery saves GHG emissions and reduces fossil energy demand. For instance, GHG emissions are reduced by about 50% and more than 80% of non-renewable energy is saved. Land use change effects have a strong influence in the final GHG balance (about 50%), and their uncertainty is discussed in a sensitivity analysis. Concerning the investigation of the other impact categories, biorefinery systems

  19. Circadian genes, rhythms and the biology of mood disorders.

    Science.gov (United States)

    McClung, Colleen A

    2007-05-01

    For many years, researchers have suggested that abnormalities in circadian rhythms may underlie the development of mood disorders such as bipolar disorder (BPD), major depression and seasonal affective disorder (SAD). Furthermore, some of the treatments that are currently employed to treat mood disorders are thought to act by shifting or "resetting" the circadian clock, including total sleep deprivation (TSD) and bright light therapy. There is also reason to suspect that many of the mood stabilizers and antidepressants used to treat these disorders may derive at least some of their therapeutic efficacy by affecting the circadian clock. Recent genetic, molecular and behavioral studies implicate individual genes that make up the clock in mood regulation. As well, important functions of these genes in brain regions and neurotransmitter systems associated with mood regulation are becoming apparent. In this review, the evidence linking circadian rhythms and mood disorders, and what is known about the underlying biology of this association, is presented.

  20. Sensory Conflict Disrupts Activity of the Drosophila Circadian Network

    Directory of Open Access Journals (Sweden)

    Ross E.F. Harper

    2016-11-01

    Full Text Available Periodic changes in light and temperature synchronize the Drosophila circadian clock, but the question of how the fly brain integrates these two input pathways to set circadian time remains unanswered. We explore multisensory cue combination by testing the resilience of the circadian network to conflicting environmental inputs. We show that misaligned light and temperature cycles can lead to dramatic changes in the daily locomotor activities of wild-type flies during and after exposure to sensory conflict. This altered behavior is associated with a drastic reduction in the amplitude of PERIOD (PER oscillations in brain clock neurons and desynchronization between light- and temperature-sensitive neuronal subgroups. The behavioral disruption depends heavily on the phase relationship between light and temperature signals. Our results represent a systematic quantification of multisensory integration in the Drosophila circadian system and lend further support to the view of the clock as a network of coupled oscillatory subunits.

  1. Genetics and Neurobiology of Circadian Clocks in Mammals

    Science.gov (United States)

    Park, Junghea; Lee, Choogon; Takahashi, Joseph S.

    2013-01-01

    In animals circadian behavior can be analyzed as an integrated system - beginning with genes leading ultimately to behavioral outputs. In the last decade, the molecular mechanism of circadian clocks has been unraveled primarily by the use of phenotype-driven (forward) genetic analysis in a number of model systems. Circadian oscillations are generated by a set of genes forming a transcriptional autoregulatory feedback loop. In mammals, there is a “core” set of circadian genes that form the primary negative feedback loop of the clock mechanism (Clock/Npas2, Bmal1, Per1, Per2, Cry1, Cry2 and CK1ε). Another dozen candidate genes have been identified and play additional roles in the circadian gene network such as the feedback loop involving Rev-erbα. Despite this remarkable progress, it is clear that a significant number of genes that strongly influence and regulate circadian rhythms in mammals remain to be discovered and identified. As part of a large-scale N-ethyl-N-nitrosourea (ENU) mutagenesis screen using a wide range of nervous system and behavioral phenotypes, we have identified a number of new circadian mutants in mice. Here we describe a new short period circadian mutant, part-time (prtm), which is caused by a loss-of-function mutation in the Cryptochrome1 gene. We also describe a long period circadian mutant named Overtime (Ovtm). Positional cloning and genetic complementation reveal that Ovtm is encoded by the F-box protein FBXL3 a component of the SKP1-CUL1-F-box-protein (SCF) E3 ubiquitin ligase complex. The Ovtm mutation causes an isoleucine to threonine (I364T) substitution leading to a loss-of-function in FBXL3 which interacts specifically with the CRYPTOCHROME (CRY) proteins. In Ovtm mice, expression of the PERIOD proteins PER1 and PER2 is reduced; however, the CRY proteins CRY1 and CRY2 are unchanged. The loss of FBXL3 function leads to a stabilization of the CRY proteins, which in turn leads to a global transcriptional repression of the Per and

  2. Modeling the effects of cell cycle M-phase transcriptional inhibition on circadian oscillation.

    Directory of Open Access Journals (Sweden)

    Bin Kang

    2008-03-01

    Full Text Available Circadian clocks are endogenous time-keeping systems that temporally organize biological processes. Gating of cell cycle events by a circadian clock is a universal observation that is currently considered a mechanism serving to protect DNA from diurnal exposure to ultraviolet radiation or other mutagens. In this study, we put forward another possibility: that such gating helps to insulate the circadian clock from perturbations induced by transcriptional inhibition during the M phase of the cell cycle. We introduced a periodic pulse of transcriptional inhibition into a previously published mammalian circadian model and simulated the behavior of the modified model under both constant darkness and light-dark cycle conditions. The simulation results under constant darkness indicated that periodic transcriptional inhibition could entrain/lock the circadian clock just as a light-dark cycle does. At equilibrium states, a transcriptional inhibition pulse of certain periods was always locked close to certain circadian phases where inhibition on Per and Bmal1 mRNA synthesis was most balanced. In a light-dark cycle condition, inhibitions imposed at different parts of a circadian period induced different degrees of perturbation to the circadian clock. When imposed at the middle- or late-night phase, the transcriptional inhibition cycle induced the least perturbations to the circadian clock. The late-night time window of least perturbation overlapped with the experimentally observed time window, where mitosis is most frequent. This supports our hypothesis that the circadian clock gates the cell cycle M phase to certain circadian phases to minimize perturbations induced by the latter. This study reveals the hidden effects of the cell division cycle on the circadian clock and, together with the current picture of genome stability maintenance by circadian gating of cell cycle, provides a more comprehensive understanding of the phenomenon of circading gating of

  3. Residual Mammographic Microcalcifications and Enhancing Lesions on MRI After Neoadjuvant Systemic Chemotherapy for Locally Advanced Breast Cancer: Correlation with Histopathologic Residual Tumor Size.

    Science.gov (United States)

    Kim, Young-Seon; Chang, Jung Min; Moon, Hyeong-Gon; Lee, Joongyub; Shin, Sung Ui; Moon, Woo Kyung

    2016-04-01

    To evaluate the accuracy of residual microcalcifications on mammogram (MG) in predicting the extent of the residual tumor after neoadjuvant systemic treatment (NST) in patients with locally advanced breast cancer and to evaluate factors affecting the accuracy of MG microcalcifications using magnetic resonance imaging (MRI) as a reference. The patients who underwent NST and showed suspicious microcalcifications on MG comprised our study population. Clinicopathologic and imaging (MG, MRI) findings were investigated. Agreement between image findings and pathology was assessed and factors affecting the discrepancy were analyzed. Among 207 patients, 196 had residual invasive ductal carcinoma or ductal carcinoma-in-situ (mean size, 3.78 cm). The overall agreement of residual microcalcifications on MG predicting residual tumor extents was lower than MRI in all tumor subtypes (intraclass correlation coefficient [ICC] = 0.368 and 0.723, p microcalcifications and pathology was highest in HR(+)/HER2(+) tumors and lowest in the triple-negative tumors (ICC = 0.417 and 0.205, respectively). Multivariate linear regression analysis revealed that a size discrepancy between microcalcifications and histopathology was correlated with molecular subtype (p = 0.005). In HR(+)/HER2(-) and triple-negative subtypes, the mean extents of residual microcalcification were smaller than residual cancer, and overestimation of tumor extent was more frequent in HR(+)/HER2(+) and HR(-)/HER2(+) tumors. The extent of microcalcifications on MG after NST showed an overall lower correlation with the extent of the pathologic residual tumor than enhancing lesions on MRI. The accuracy of residual tumor evaluation after NST with MG and MRI is affected by their molecular subtype.

  4. Circadian variation of cardiac autonomic nervous profile is affected in Japanese ambulance men with a working system of 24-h shifts.

    Science.gov (United States)

    Mitani, Satoko; Fujita, Masatoshi; Shirakawa, Taro

    2006-01-01

    The purpose of this study was to compare the stress levels of Japanese ambulance men between on-duty and off-duty days, by using the physiological indices of heart rate variability (HRV) and cortisol in urine, measured over each 24-h period. Measurements were made during one on-duty and one off-duty day for each subject. The participants were monitored for 24 h with a Holter recording system and a parameter reflecting overall stress levels was obtained by measuring the cortisol level in urine collected over 24 h. The circadian variation of cardiac autonomic nervous system activity was affected when the subjects were on duty. The low-frequency/high-frequency power ratio (=low-frequency power/high-frequency power: LF/HF), which is a useful parameter that reflects the balance of cardiac autonomic nervous activity, differed significantly between the waking and sleeping times on the off-duty day (P=0.03), while it did not differ between these two states on the on-duty day (P=0.56). Similarly, the normalized high-frequency power [=high-frequency/(high-frequency+low-frequency) power: HF/(HF+LF)] ratio, which is a useful measure of the activity of the parasympathetic nervous system, differed significantly between these two states on the off-duty day (P=0.04), while there was no significant difference in the ratio between the two states on the on-duty day (P=0.13). These results show that the diurnal balance of the cardiac autonomic nervous system is affected on the on-duty day, even though it is possible for ambulance men to sleep regular hours.

  5. Dynamical Analysis of bantam-Regulated Drosophila Circadian Rhythm Model

    Science.gov (United States)

    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.

  6. Circadian rhythm and sleep influences on digestive physiology and disorders

    Directory of Open Access Journals (Sweden)

    Vaughn BV

    2014-09-01

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

  7. Deficiency of circadian protein CLOCK reduces lifespan and increases age-related cataract development in mice

    OpenAIRE

    Dubrovsky, Yuliya V.; Samsa, William E.; Kondratov, Roman V.

    2010-01-01

    Circadian clock is implicated in the regulation of aging. The transcription factor CLOCK, a core component of the circadian system, operates in complex with another circadian clock protein BMAL1. Recently it was demonstrated that BMAL1 deficiency results in premature aging in mice. Here we investigate the aging of mice deficient for CLOCK protein. Deficiency of the CLOCK protein significantly affects longevity: the average lifespan of Clock−/− mice is reduced by 15% compared with wild type mi...

  8. Thermal treatment system of hazardous residuals in three heating zones based on a microprocessor

    International Nuclear Information System (INIS)

    Luna H, C.L.

    1997-01-01

    Thermal treatment system consists of a high power electric oven of three heating zones where each zone works up to 1200 Centigrades; it has the capacity of rising the central zone temperature up to 1000 Centigrades in 58 minutes approximately. This configuration of three zones could be programmed to different temperatures and they will be digitally controlled by a control microprocessor, which has been controlled by its own assembler language, in function of the PID control. There are also other important controls based on this microprocessor, as a signal amplification, starting and shutdown of high power step relays, activation and deactivation of both analogic/digital and digital/analogic convertors, port activation and basic data storage of the system. Two main characteristics were looked for this oven design; the first was the possibility of controlling the three zone temperature and the second was to reduce the rising and stabilization operation time and its digitized control. The principal function of the three zone oven is to accelerate the degradation of hazardous residuals by an oxidation instead combustion, through relatively high temperatures (minimum 800 Centigrades and maximum 1200 Centigrades); this process reduces the ash and volatile particulate production. The hazardous residuals will be pumped into the degradation system and after atomized through a packaged column; this step will avoid the direct contact of the residuals with the oven cores. These features make this system as closed process, which means that the residuals can not leak to the working area, reducing the exposure risk to the personnel. This three step oven system is the first stage of the complete hazardous residuals degradation system; after this, the flow will go into a cold plasma region where the process is completed, making a closed system. (Author)

  9. 76 FR 51038 - Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...

    Science.gov (United States)

    2011-08-17

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-D-0246] Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA...

  10. Aging assessment of Residual Heat Removal systems in Boiling Water Reactors

    International Nuclear Information System (INIS)

    Lofaro, R.J.; Aggarwal, S.

    1992-01-01

    The effects of aging on Residual Heat Removal systems in Boiling Water Reactors have been studied as part of the Nuclear Plant Aging Research Program. The aging phenomena has been characterized by analyzing operating experience from various national data bases. In addition, actual plant data was obtained to supplement and validate the data base findings

  11. Design of A District Heating System Including The Upgrading of Residual Industrial Waste Heat

    NARCIS (Netherlands)

    Falcao, P.W.; Mesbah, A.; Suherman, M.V.; Wennekes, S.

    2005-01-01

    This study was aimed to evaluate the feasibility of using a waste heat stream from DSM for a District Heating System. A conceptual design was carried out with emphasis on the unit for upgrading the residual waste heat. Having reviewed heat pump technology, mechanical heat pump was found to be the

  12. Financial performance of a mobile pyrolysis system used to produce biochar from sawmill residues

    Science.gov (United States)

    Dongyeob Kim; Nathaniel McLean Anderson; Woodam Chung

    2015-01-01

    Primary wood products manufacturers generate significant amounts of woody biomass residues that can be used as feedstocks for distributed-scale thermochemical conversion systems that produce valuable bioenergy and bioproducts. However, private investment in these technologies is driven primarily by financial performance, which is often unknown for new technologies with...

  13. Circadian rhythm, sleep pattern, and metabolic consequences: an overview on cardiovascular risk factors.

    Science.gov (United States)

    Machado, Roberta Marcondes; Koike, Marcia Kiyomi

    2014-04-01

    Sleep duration is a risk factor for cardiovascular disease. Alteration in sleep pattern can induce the loss of circadian rhythmicity. Chronically, this desynchronization between endogenous rhythm and behavioral cycles can lead to an adverse metabolic profile, a proinflammatory condition and can increase the risk of cardiovascular disease. The circadian cycle can vary due to environmental cues. The circadian pacemaker is located in the suprachiasmatic nuclei; this central clock coordinates the circadian rhythm in the central nervous system and peripheral tissues. The mechanisms involved in sleep disturbance, circadian misalignment and adverse metabolic effects have yet to be fully elucidated. This review looks over the association among sleep alteration, circadian rhythm and the development of risk factors implicated in cardiovascular disease.

  14. Transcriptional feedback and definition of the circadian pacemaker in Drosophila and animals.

    Science.gov (United States)

    Rosbash, M; Bradley, S; Kadener, S; Li, Y; Luo, W; Menet, J S; Nagoshi, E; Palm, K; Schoer, R; Shang, Y; Tang, C-H A

    2007-01-01

    The modern era of Drosophila circadian rhythms began with the landmark Benzer and Konopka paper and its definition of the period gene. The recombinant DNA revolution then led to the cloning and sequencing of this gene. This work did not result in a coherent view of circadian rhythm biochemistry, but experiments eventually gave rise to a transcription-centric view of circadian rhythm generation. Although these circadian transcription-translation feedback loops are still important, their contribution to core timekeeping is under challenge. Indeed, kinases and posttranslational regulation may be more important, based in part on recent in vitro work from cyanobacteria. In addition, kinase mutants or suspected kinase substrate mutants have unusually large period effects in Drosophila. This chapter discusses our recent experiments, which indicate that circadian transcription does indeed contribute to period determination in this system. We propose that cyanobacteria and animal clocks reflect two independent origins of circadian rhythms.

  15. Unavailability of the residual system heat removal of Angra 1 by Bayesian networks considering dependent failures

    International Nuclear Information System (INIS)

    Gomes, Many R.S.; Melo, Paulo F.F.F. e

    2015-01-01

    This work models by Bayesian networks the residual heat removal system (SRCR) of Angra I nuclear power plant, using fault tree mapping for systematically identifying all possible modes of occurrence caused by a large loss of coolant accident (large LOCA). The focus is on dependent events, such as the bridge system structure of the residual heat removal system and the occurrence of common-cause failures. We used the Netica™ tool kit, Norsys Software Corporation and Python 2.7.5 for modeling Bayesian networks and Microsoft Excel for modeling fault trees. Working with dependent events using Bayesian networks is similar to the solutions proposed by other models, beyond simple understanding and ease of application and modification throughout the analysis. The results obtained for the unavailability of the system were satisfactory, showing that in most cases the system will be available to mitigate the effects of an accident as described above. (author)

  16. How does general anaesthesia affect the circadian clock?

    Science.gov (United States)

    Poulsen, Raewyn C; Warman, Guy R; Sleigh, Jamie; Ludin, Nicola M; Cheeseman, James F

    2018-02-01

    Post-operative patients experience sleep disturbances. Animal studies demonstrate that general anaesthesia (GA) can disrupt circadian rhythms and cause changes in the molecular clock, indicating that anaesthesia contributes to post-operative circadian disruption. Here we review the effect of anaesthesia on the circadian clock and its rhythms in order to summarise current findings outline commonalities between studies and propose mechanisms by which effects may be mediated. 1) GA has strong effects on the main neurotransmitter systems linked with circadian control (Gamma aminobutyric acid/N-methyl-D-aspartate (GABA/NMDA)) and may act by interfering with light-entrainment of the clock. 2) Expression of the core clock gene per2 is inhibited by GA (possibly via a NMDA/glycogen synthase kinase 3β (GSK3β) pathway). 3) GA's effect on circadian rhythms appears greatest when administered during animals' active phases 4) GA may have different effects when administered under free-running and entrained conditions. 5) Anaesthesia may mimic the mechanism involved in adaptation of the clock to changes in daylength. There is agreement that GA can strongly affect the circadian clock. How anaesthesia-induced changes in the molecular clock lead to changes in behaviour remains unclear. The answer, and what it may mean for patients post-operatively, will rely on systematic studies at molecular, behavioural, and clinical levels using standardised protocols. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. An epithelial circadian clock controls pulmonary inflammation and glucocorticoid action.

    Science.gov (United States)

    Gibbs, Julie; Ince, Louise; Matthews, Laura; Mei, Junjie; Bell, Thomas; Yang, Nan; Saer, Ben; Begley, Nicola; Poolman, Toryn; Pariollaud, Marie; Farrow, Stuart; DeMayo, Francesco; Hussell, Tracy; Worthen, G Scott; Ray, David; Loudon, Andrew

    2014-08-01

    The circadian system is an important regulator of immune function. Human inflammatory lung diseases frequently show time-of-day variation in symptom severity and lung function, but the mechanisms and cell types underlying these effects remain unclear. We show that pulmonary antibacterial responses are modulated by a circadian clock within epithelial club (Clara) cells. These drive circadian neutrophil recruitment to the lung via the chemokine CXCL5. Genetic ablation of the clock gene Bmal1 (also called Arntl or MOP3) in bronchiolar cells disrupts rhythmic Cxcl5 expression, resulting in exaggerated inflammatory responses to lipopolysaccharide and an impaired host response to Streptococcus pneumoniae infection. Adrenalectomy blocks rhythmic inflammatory responses and the circadian regulation of CXCL5, suggesting a key role for the adrenal axis in driving CXCL5 expression and pulmonary neutrophil recruitment. Glucocorticoid receptor occupancy at the Cxcl5 locus shows circadian oscillations, but this is disrupted in mice with bronchiole-specific ablation of Bmal1, leading to enhanced CXCL5 expression despite normal corticosteroid secretion. The therapeutic effects of the synthetic glucocorticoid dexamethasone depend on intact clock function in the airway. We now define a regulatory mechanism that links the circadian clock and glucocorticoid hormones to control both time-of-day variation and the magnitude of pulmonary inflammation and responses to bacterial infection.

  18. Genetic Disruption of the Core Circadian Clock Impairs Hippocampus-Dependent Memory

    Science.gov (United States)

    Wardlaw, Sarah M.; Phan, Trongha X.; Saraf, Amit; Chen, Xuanmao; Storm, Daniel R.

    2014-01-01

    Perturbing the circadian system by electrolytically lesioning the suprachiasmatic nucleus (SCN) or varying the environmental light:dark schedule impairs memory, suggesting that memory depends on the circadian system. We used a genetic approach to evaluate the role of the molecular clock in memory. Bmal1[superscript -/-] mice, which are arrhythmic…

  19. “What watch?... such much!” Complexity and evolution of circadian clocks

    NARCIS (Netherlands)

    Roenneberg, Till; Merrow, Martha

    2002-01-01

    This review uses three examples to summarise our knowledge about the complexity and the evolution of circadian systems. The first example describes the ecology of unicellular algae, which use their circadian system to optimise the daily exploitation of resources that are spatially separated. The

  20. Central Circadian Control of Female Reproductive Function

    Directory of Open Access Journals (Sweden)

    Brooke H Miller

    2014-01-01

    Full Text Available Over the past two decades, it has become clear just how much of our physiology is under the control of the suprachiasmatic nucleus (SCN and the cell-intrinsic molecular clock that ticks with a periodicity of approximately 24 hours. The SCN prepares our digestive system for meals, our adrenal axis for the stress of waking up in the morning, and the genes expressed in our muscles when we prepare to exercise, Long before molecular studies of genes such as Clock, Bmal1, and the Per homologs were possible, it was obvious that female reproductive function was under strict circadian control at every level of the hypothalamic-pituitary-gonadal (HPG axis, and in the establishment and successful maintenance of pregnancy. This review highlights our current understanding of the role that the SCN plays in regulating female reproductive physiology, with a special emphasis on the advances made possible through the use of circadian mutant mice.

  1. Nocturia: The circadian voiding disorder

    Directory of Open Access Journals (Sweden)

    Jin Wook Kim

    2016-05-01

    Full Text Available Nocturia is a prevalent condition of waking to void during the night. The concept of nocturia has evolved from being a symptomatic aspect of disease associated with the prostate or bladder to a form of lower urinary tract disorder. However, recent advances in circadian biology and sleep science suggest that it might be important to consider nocturia as a form of circadian dysfunction. In the current review, nocturia is reexamined with an introduction to sleep disorders and recent findings in circadian biology in an attempt to highlight the importance of rediscovering nocturia as a problem of chronobiology.

  2. Circadian rhythms of fetal liver transcription persist in the absence of canonical circadian clock gene expression rhythms in vivo.

    Directory of Open Access Journals (Sweden)

    Chengwei Li

    Full Text Available The cellular circadian clock and systemic cues drive rhythmicity in the transcriptome of adult peripheral tissues. However, the oscillating status of the circadian clocks in fetal tissues, and their response to maternal cues, are less clear. Most clock genes do not cycle in fetal livers from mice and rats, although tissue level rhythms rapidly emerge when fetal mouse liver explants are cultured in vitro. Thus, in the fetal mouse liver, the circadian clock does not oscillate at the cellular level (but is induced to oscillate in culture. To gain a comprehensive overview of the clock status in the fetal liver during late gestation, we performed microarray analyses on fetal liver tissues. In the fetal liver we did not observe circadian rhythms of clock gene expression or many other transcripts known to be rhythmically expressed in the adult liver. Nevertheless, JTK_CYCLE analysis identified some transcripts in the fetal liver that were rhythmically expressed, albeit at low amplitudes. Upon data filtering by coefficient of variation, the expression levels for transcripts related to pancreatic exocrine enzymes and zymogen secretion were found to undergo synchronized daily fluctuations at high amplitudes. These results suggest that maternal cues influence the fetal liver, despite the fact that we did not detect circadian rhythms of canonical clock gene expression in the fetal liver. These results raise important questions on the role of the circadian clock, or lack thereof, during ontogeny.

  3. Asymptotic Solutions of Time-Space Fractional Coupled Systems by Residual Power Series Method

    Directory of Open Access Journals (Sweden)

    Wenjin Li

    2017-01-01

    Full Text Available This paper focuses on the asymptotic solutions to time-space fractional coupled systems, where the fractional derivative and integral are described in the sense of Caputo derivative and Riemann-Liouville integral. We introduce the Residual Power Series (for short RPS method to construct the desired asymptotic solutions. Furthermore, we apply this method to some time-space fractional coupled systems. The simplicity and efficiency of RPS method are shown by the application.

  4. Increased Sensitivity of the Circadian System to Temporal Changes in the Feeding Regime of Spontaneously Hypertensive Rats - A Potential Role for Bmal2 in the Liver

    Czech Academy of Sciences Publication Activity Database

    Polidarová, Lenka; Sládek, Martin; Nováková, Marta; Parkanová, Daniela; Sumová, Alena

    2013-01-01

    Roč. 8, č. 9 (2013), e75690 E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GAP303/11/0668 Institutional support: RVO:67985823 Keywords : circadian * clock gene * metabolism * liver * feeding regime * Bmal2 * spontaneously hypertensive rat Subject RIV: ED - Physiology Impact factor: 3.534, year: 2013

  5. Comparison of finishing and polishing systems for residual resin removal after debonding

    Directory of Open Access Journals (Sweden)

    Çaöry Ulusoy

    2009-06-01

    Full Text Available OBJECTIVE : The aim of this study was to evaluate (1 the effectiveness of one-step polishers on the surface morphology of enamel using scanning electron microscope (SEM and compare their effects with conventional systems for residual adhesive removal; and (2 the time spent to remove resin remnants. MATERIAL AND METHODS: Metal brackets were bonded to the buccal surface of 80 freshly extracted human premolar teeth and received the same resin-removal methods to evaluate the time spent to remove resin remnants (n=10. The brackets were debonded and residual adhesive was removed using different systems. Fourty-five premolars, including the control group with intact enamel (n=5, were examined by SEM. RESULTS: 30-blade tungsten carbide burs were the least time-consuming procedure. The best system in SEM study was the PoGo micro-polishers followed by Super-Snap Rainbow system. CONCLUSIONS: The effect of polishing systems on residual resin removal was dependent on the characteristics of the instruments in each system.

  6. Calculation of residual electricity mixes when accounting for the EECS (European Electricity Certificate System) - The need for a harmonised system

    International Nuclear Information System (INIS)

    Raadal, H. L.; Nyland, C. A.; Hanssen, O. J.

    2009-01-01

    According to the Electricity Directive, suppliers of electricity must disclose their electricity portfolio with regards to energy source and environmental impact. This paper gives some examples of disclosure systems and residual electricity mixes in Norway, Sweden and Finland, compared to an approach based on a common regional disclosure. Disclosures based on the E-TRACK standard are presented, as well as the variation in CO 2 emissions from different residual mixes. The results from this study clearly show that there is a need for a harmonised, transparent and reliable system for the accounting of electricity disclosure in Europe. (author)

  7. Ras-mediated deregulation of the circadian clock in cancer.

    Directory of Open Access Journals (Sweden)

    Angela Relógio

    Full Text Available Circadian rhythms are essential to the temporal regulation of molecular processes in living systems and as such to life itself. Deregulation of these rhythms leads to failures in biological processes and eventually to the manifestation of pathological phenotypes including cancer. To address the questions as to what are the elicitors of a disrupted clock in cancer, we applied a systems biology approach to correlate experimental, bioinformatics and modelling data from several cell line models for colorectal and skin cancer. We found strong and weak circadian oscillators within the same type of cancer and identified a set of genes, which allows the discrimination between the two oscillator-types. Among those genes are IFNGR2, PITX2, RFWD2, PPARγ, LOXL2, Rab6 and SPARC, all involved in cancer-related pathways. Using a bioinformatics approach, we extended the core-clock network and present its interconnection to the discriminative set of genes. Interestingly, such gene signatures link the clock to oncogenic pathways like the RAS/MAPK pathway. To investigate the potential impact of the RAS/MAPK pathway - a major driver of colorectal carcinogenesis - on the circadian clock, we used a computational model which predicted that perturbation of BMAL1-mediated transcription can generate the circadian phenotypes similar to those observed in metastatic cell lines. Using an inducible RAS expression system, we show that overexpression of RAS disrupts the circadian clock and leads to an increase of the circadian period while RAS inhibition causes a shortening of period length, as predicted by our mathematical simulations. Together, our data demonstrate that perturbations induced by a single oncogene are sufficient to deregulate the mammalian circadian clock.

  8. Ras-Mediated Deregulation of the Circadian Clock in Cancer

    Science.gov (United States)

    Relógio, Angela; Thomas, Philippe; Medina-Pérez, Paula; Reischl, Silke; Bervoets, Sander; Gloc, Ewa; Riemer, Pamela; Mang-Fatehi, Shila; Maier, Bert; Schäfer, Reinhold; Leser, Ulf; Herzel, Hanspeter; Kramer, Achim; Sers, Christine

    2014-01-01

    Circadian rhythms are essential to the temporal regulation of molecular processes in living systems and as such to life itself. Deregulation of these rhythms leads to failures in biological processes and eventually to the manifestation of pathological phenotypes including cancer. To address the questions as to what are the elicitors of a disrupted clock in cancer, we applied a systems biology approach to correlate experimental, bioinformatics and modelling data from several cell line models for colorectal and skin cancer. We found strong and weak circadian oscillators within the same type of cancer and identified a set of genes, which allows the discrimination between the two oscillator-types. Among those genes are IFNGR2, PITX2, RFWD2, PPARγ, LOXL2, Rab6 and SPARC, all involved in cancer-related pathways. Using a bioinformatics approach, we extended the core-clock network and present its interconnection to the discriminative set of genes. Interestingly, such gene signatures link the clock to oncogenic pathways like the RAS/MAPK pathway. To investigate the potential impact of the RAS/MAPK pathway - a major driver of colorectal carcinogenesis - on the circadian clock, we used a computational model which predicted that perturbation of BMAL1-mediated transcription can generate the circadian phenotypes similar to those observed in metastatic cell lines. Using an inducible RAS expression system, we show that overexpression of RAS disrupts the circadian clock and leads to an increase of the circadian period while RAS inhibition causes a shortening of period length, as predicted by our mathematical simulations. Together, our data demonstrate that perturbations induced by a single oncogene are sufficient to deregulate the mammalian circadian clock. PMID:24875049

  9. The circadian clock and asthma.

    Science.gov (United States)

    Durrington, Hannah J; Farrow, Stuart N; Loudon, Andrew S; Ray, David W

    2014-01-01

    It is characteristic of asthma that symptoms worsen overnight, particularly in the early hours of the morning. Nocturnal symptoms in asthma are common and are an important indicator for escalation of treatment. An extensive body of research has demonstrated that nocturnal symptoms of cough and dyspnea are accompanied by circadian variations in airway inflammation and physiologic variables, including airflow limitation and airways hyper-responsiveness. The molecular apparatus that underpins circadian variations, controlled by so called 'clock' genes, has recently been characterised. Clock genes control circadian rhythms both centrally, in the suprachiasmatic nucleus of the brain and peripherally, within every organ of the body. Here, we will discuss how clock genes regulate circadian rhythms. We will focus particularly on the peripheral lung clock and the peripheral immune clock and discuss how these might relate to both the pathogenesis and treatment of asthma.

  10. Temporal Regulation of Cytokines by the Circadian Clock

    Directory of Open Access Journals (Sweden)

    Atsuhito Nakao

    2014-01-01

    Full Text Available Several parameters of the immune system exhibit oscillations with a period of approximately 24 hours that refers to “circadian rhythms.” Such daily variations in host immune system status might evolve to maximize immune reactions at times when encounters with pathogens are most likely to occur. However, the mechanisms behind circadian immunity have not been fully understood. Recent studies reveal that the internal time keeping systemcircadian clock” plays a key role in driving the daily rhythms evident in the immune system. Importantly, several studies unveil molecular mechanisms of how certain clock proteins (e.g., BMAL1 and CLOCK temporally regulate expression of cytokines. Since cytokines are crucial mediators for shaping immune responses, this review mainly summarizes the new knowledge that highlights an emerging role of the circadian clock as a novel regulator of cytokines. A greater understanding of circadian regulation of cytokines will be important to exploit new strategies to protect host against infection by efficient cytokine induction or to treat autoimmunity and allergy by ameliorating excessive activity of cytokines.

  11. Pesticide residue assessment in three selected agricultural production systems in the Choluteca River Basin of Honduras

    International Nuclear Information System (INIS)

    Kammerbauer, J.; Moncada, J.

    1999-01-01

    There is a basic lack of information about the presence of pesticide residues in the environment in Central America. Over the period of February 1995 to June 1997, river, well, lagoon and spring water samples, as well as soil, fish tissue, lagoon bed sediments and some foodstuffs were taken from the greater Cholutecan River Basin of Honduras and analyzed for pesticide residues. These were collected at three separate sites (La Lima, Zamorano and Choluteca), each characterized by differing agricultural production systems. The main pesticide residues found in soil samples were dieldrin and p,p'-DDT, while river water samples were found to have detectable levels of heptachlor, endosulfan and chlorpyrifos, with lagoon and well water also being shown to contain heptachlor. These pesticides detected were in more than 20% of the samples assessed. In river water samples more pesticide residues at higher concentrations were found to be associated with areas of more intensive agricultural production. The fewest pesticides with lowest concentrations were found in the small subwatershed associated with traditional agricultural production. Although the pesticides found in the soils at the three sites were generally similar they tended to be higher in the southern part of the Cholutecan watershed, followed by the central zone, with the lowest concentrations being found in the more traditional production zone. In lagoon and well water samples more pesticides, but mostly in lower concentrations were detected at the traditional production site than at the others. Ten pesticide compounds were detected in fish tissue, mainly organochlorines, some of which were also found in lagoon sediments. In terms of food products, almost no pesticides were detected in vegetables, but the kidney adipose tissue taken from slaughtered cows was shown to have a tendency to contain some organochlorines. Spring water in the traditional agricultural production zone contained three organochlorine compounds

  12. Imaging Multidimensional Therapeutically Relevant Circadian Relationships

    Directory of Open Access Journals (Sweden)

    Jamil Singletary

    2009-01-01

    Full Text Available Circadian clocks gate cellular proliferation and, thereby, therapeutically target availability within proliferative pathways. This temporal coordination occurs within both cancerous and noncancerous proliferating tissues. The timing within the circadian cycle of the administration of drugs targeting proliferative pathways necessarily impacts the amount of damage done to proliferating tissues and cancers. Concurrently measuring target levels and associated key pathway components in normal and malignant tissues around the circadian clock provides a path toward a fuller understanding of the temporal relationships among the physiologic processes governing the therapeutic index of antiproliferative anticancer therapies. The temporal ordering among these relationships, paramount to determining causation, is less well understood using two- or three-dimensional representations. We have created multidimensional multimedia depictions of the temporal unfolding of putatively causative and the resultant therapeutic effects of a drug that specifically targets these ordered processes at specific times of the day. The systems and methods used to create these depictions are provided, as well as three example supplementary movies.

  13. Circadian and sleep disorders in Parkinson's disease.

    Science.gov (United States)

    Videnovic, Aleksandar; Golombek, Diego

    2013-05-01

    Impaired sleep and alertness, initially recognized by James Parkinson in his famous monograph "An Essay on the Shaking Palsy" in 1817, is one of the most common and disabling nonmotor symptoms of Parkinson's disease (PD). It is only recently, however, that sleep disturbances in PD have received the attention of medical and research community. Dopamine, the major neurotransmitter implicated in the pathogenesis of PD, plays a pivotal role in the regulation of sleep and circadian homeostasis. Sleep dysfunction affects up to 90% of patients with PD, and may precede the onset of the disease by decades. Sleep dysfunction in PD may be categorized into disturbances of overnight sleep and daytime alertness. Etiology of impaired sleep and alertness in PD is multifactorial. Co-existent primary sleep disorders, medication side effects, overnight re-emergence of motor symptoms, and primary neurodegeneration itself, are main causes of sleep disruption and excessive daytime sleepiness among patients with PD. Increasing body of evidence suggests that the circadian system becomes dysregulated in PD, which may lead to poor sleep and alertness. Treatment options are limited and frequently associated with unwanted side effects. Further studies that will examine pathophysiology of sleep dysfunction in PD, and focus on novel treatment approaches are therefore very much needed. In this article we review the role of dopamine in regulation of sleep and alertness and discuss main sleep and circadian disturbances associated with PD. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Links between circadian rhythms and psychiatric disease

    Directory of Open Access Journals (Sweden)

    Ilia N Karatsoreos

    2014-05-01

    Full Text Available Determining the cause of psychiatric disorders is a goal of modern neuroscience, and will hopefully lead to the discovery of treatments to either prevent or alleviate the suffering caused by these diseases. One roadblock to attaining this goal is the realization that neuropsychiatric diseases are rarely due to a single gene polymorphism, environmental exposure, or developmental insult. Rather, it is a complex interaction between these various influences that likely leads to the development of clinically relevant syndromes. Our lab is exploring the links between environmental exposures and neurobehavioral function by investigating how disruption of the circadian (daily clock alters the structure and function of neural circuits, with the hypothesis that disrupting this crucial homeostatic system can directly contribute to altered vulnerability of the organism to other factors that interact to produce psychiatric illness. This review explores some historical and more recent findings that link disrupted circadian clocks to neuropsychiatric disorders, particularly depression, mania, and schizophrenia. We take a comparative approach by exploring the effects observed in human populations, as well as some experimental models used in the laboratory to unravel mechanistic and causal relationships between disruption of the circadian clock and behavioral abnormalities. This is a rich area of research that we predict will contribute greatly to our understanding of how genes, environment, and development interact to modulate an individual’s vulnerability to psychiatric disorders.

  15. Plant Residual Management in different Crop Rotations System on Potato Tuber Yield Loss Affected by Wireworms

    Directory of Open Access Journals (Sweden)

    A. Zarea Feizabadi

    2016-07-01

    Full Text Available Introduction: Selection a proper crop rotation based on environmental conservation rules is a key factor for increasing long term productivity. On the other hand, the major problem in reaching agricultural sustainability is lack of soil organic matter. Recently, a new viewpoint has emerged based on efficient use of inputs, environmental protection, ecological economy, food supply and security. Crop rotation cannot supply and restore plant needed nutrients, so gradually the productivity of rotation system tends to be decreased. Returning the plant residues to the soil helps to increase its organic matter and fertility in long-term period. Wireworms are multi host pests and we can see them in wheat and barley too. The logic way for their control is agronomic practices like as crop rotation. Wireworms’ population and damages are increased with using grasses and small seed gramineas in mild winters, variation in cropping pattern, reduced chemical control, and cover crops in winter. In return soil cultivation, crop rotation, planting date, fertilizing, irrigation and field health are the examples for the effective factors in reducing wireworms’ damage. Materials and Methods: In order to study the effect of crop rotations, residue management and yield damage because of wireworms’ population in soil, this experiment was conducted using four rotation systems for five years in Jolgeh- Rokh agricultural research station. Crop rotations were included, 1 Wheat monoculture for the whole period (WWWWW, 2 Wheat- wheat- wheat- canola- wheat (WWWCW, 3 Wheat- sugar beet- wheat- potato- wheat (WSWPW, 4 Wheat- maize- wheat- potato- wheat (WMWPW as main plots and three levels of returning crop residues to soil (returning 0, 50 and 100% produced crop residues to soil were allocated as sub plots. This experiment was designed as split plot based on RCBD design with three replications. After ending each rotation treatment, the field was sowed with potato cv. Agria

  16. Vision-Inspection System for Residue Monitoring of Ready-Mixed Concrete Trucks

    Directory of Open Access Journals (Sweden)

    Deok-Seok Seo

    2015-01-01

    Full Text Available The objective of this study is to propose a vision-inspection system that improves the quality management for ready-mixed concrete (RMC. The proposed system can serve as an alternative to the current visual inspection method for the detection of residues in agitator drum of RMC truck. To propose the system, concept development and the system-level design should be executed. The design considerations of the system are derived from the hardware properties of RMC truck and the conditions of RMC factory, and then 6 major components of the system are selected in the stage of system level design. The prototype of system was applied to a real RMC plant and tested for verification of its utility and efficiency. It is expected that the proposed system can be employed as a practical means to increase the efficiency of quality management for RMC.

  17. Automatic Gamma-Scanning System for Measurement of Residual Heat in Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Osifo, Otasowie

    2007-03-01

    In Sweden, spent nuclear fuel will be encapsulated and placed in a deep geological repository. In this procedure, reliable and accurate spent fuel data such as discharge burnup, cooling time and residual heat must be available. The gamma scanning method was proposed in earlier work as a fast and reliable method for the experimental determination of such spent fuel data. This thesis is focused on the recent achievements in the development of a pilot gamma scanning system and its application in measuring spent fuel residual heat. The achievements include the development of dedicated spectroscopic data-acquisition and analysis software and the use of a specially designed calorimeter for calibrating the gamma scanning system. The pilot system is described, including an evaluation of the performance of the spectrum analysis software. Also described are the gamma-scanning measurements on 31 spent PWR fuel assemblies performed using the pilot system. The results obtained for the determination of residual heat are presented, showing an agreement of (2-3) % with both calorimetric and calculated data. In addition, the ability to verify declared data such as discharge burnup and cooling time is demonstrated

  18. Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Teixeira

    2013-10-01

    Full Text Available Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp. residues to the short-term CO2-C loss, we studied the influence of several tillage systems: heavy offset disk harrow (HO, chisel plow (CP, rotary tiller (RT, and sugarcane mill tiller (SM in 2008, and CP, RT, SM, moldboard (MP, and subsoiler (SUB in 2009, with and without sugarcane residues relative to no-till (NT in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47 % and 41 %, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

  19. Systemic therapy with oncolytic myxoma virus cures established residual multiple myeloma in mice

    Directory of Open Access Journals (Sweden)

    Eric Bartee

    2016-01-01

    Full Text Available Multiple myeloma is an incurable malignancy of plasma B-cells. Traditional chemotherapeutic regimes often induce initial tumor regression; however, virtually all patients eventually succumb to relapse caused by either reintroduction of disease during autologous transplant or expansion of chemotherapy resistant minimal residual disease. It has been previously demonstrated that an oncolytic virus known as myxoma can completely prevent myeloma relapse caused by reintroduction of malignant cells during autologous transplant. The ability of this virus to treat established residual disease in vivo, however, remained unknown. Here we demonstrate that intravenous administration of myxoma virus into mice bearing disseminated myeloma results in the elimination of 70–90% of malignant cells within 24 hours. This rapid debulking was dependent on direct contact of myxoma virus with residual myeloma and did not occur through destruction of the hematopoietic bone marrow niche. Importantly, systemic myxoma therapy also induced potent antimyeloma CD8+ T cell responses which localized to the bone marrow and were capable of completely eradicating established myeloma in some animals. These results demonstrate that oncolytic myxoma virus is not only effective at preventing relapse caused by reinfusion of tumor cells during stem cell transplant, but is also potentially curative for patients bearing established minimal residual disease.

  20. Tradeoffs in Crop Residue Utilization in Mixed Crop-Livestock Systems and Implications for Conservation Agriculture and Sustainable Land Management

    OpenAIRE

    Jaleta, Moti; Kassie, Menale; Shiferaw, Bekele A.

    2012-01-01

    Crop residue use for soil mulch and animal feed are the two major competing purposes and the basic source of fundamental challenge in conservation agriculture (CA) where residue retention on farm plots is one of the three CA principles. Using survey data from Kenya and applying bivariate ordered Probit and bivariate Tobit models, this paper analyzes the tradeoffs in maize residue use as soil mulch and livestock feed in mixed farming systems. Results show that both the proportion and quantity ...

  1. Nuclear reactor equipped with a flooding tank and a residual heat removal and emergency cooling system

    International Nuclear Information System (INIS)

    Schabert, H.P.; Winkler, F.

    1975-01-01

    A description is given of a nuclear reactor such as a pressurized-water reactor or the like which is equipped with a flooding tank and a residual heat removal and emergency cooling system. The flooding tank is arranged within the containment shell at an elevation above the upper edge of the reactor core and contains a liquid for flooding the reactor core in the event of a loss of coolant

  2. Failure Modes and Effects Analysis (FMEA) of the Residual Heat Removal System

    International Nuclear Information System (INIS)

    Eggleston, F.T.

    1976-01-01

    The Residual Heat Removal System (RHRS) transfer heat from the Reactor Coolant System (RCS) to the reactor plant Component Cooling System (CCS) to reduce the temperature of the RCS at a controlled rate during the second part of normal plant cooldown and maintains the desired temperature until the plant is restarted. By the use of an analytic tool, the Failure Modes and Effects Analysis, it is shown that the RHRS, because of its redundant two train design, is able to accommodate any credible component single failure with the only effect being an extension in the required cooldown time, thus demonstrating the reliability of the RHRS to perform its intended function

  3. Financial cost-benefit analysis of investment possibilities in district heating system on wood residues

    Directory of Open Access Journals (Sweden)

    Stošić Ivan

    2017-01-01

    Full Text Available The purpose of this research is to provide feasibility analysis of a long-term sustainable development concept for district heating based on wood residues. In this paper, the experimental study has been conducted starting from the data collected by field researches in municipality of Trstenik (town in Serbia with district heating system currently based on heavy fuel oil and lignite. Using the method of Financial Cost-Benefit Analysis, this study evaluates financial efficiency of investment in district heating plant based on wood residues and energy savings in district heating system. Findings show that such investment could be profitable from the financial point of view: Net Present Value of investment is positive, Financial Rate of Return is high (30.69%, and the pay-back period is relatively favourable (7 years. Moreover, the presented SWOT indicates that there are realistic prospects of implementation of district heating based on wood residues. However, this does not mean everything will go smoothly and easily, keeping in mind a number of challenges that each new concept of district heating contains immanently. Nevertheless, the results of this research could provide useful inputs for the decision makers when selecting appropriate models for improving performance of municipal district heating systems.

  4. Pesticide residues in apples grown under a conventional and integrated pest management system.

    Science.gov (United States)

    Mladenova, R; Shtereva, D

    2009-06-01

    This paper describes method validation for determination of more than 40 pesticides in apples using a GC technique. Target compounds belonged to the organochlorine, organophosphorus, carbamates, pyrethroids, triazoles, dicarboximides and strobilurins groups, among others. Sample preparation consisted of acetone extraction and subsequent cleanup/concentration by SPE with a polymer-based sorbent. Single quadrupole GC-MS operating in SIM mode and electron impact ionization was used for identification and quantification of the pesticides. Average recoveries for analytes ranged between 70 and 110% at three fortification levels - 0.01, 0.1 and 0.2 mg kg(-1). Relative standard deviations were lower than 20% for all tested compounds. Calculated limits of detection and limits of quantification were below 0.01 mg kg(-1), which were sufficiently low compared to the maximum residue levels (MRLs) established by European legislation. The proposed method was applied for determination of pesticide residue in four selected apple varieties after harvesting. Whole and processed fruits (peel and peeled fruits) were analyzed from different treatment systems: two conventional, one based on integrated pest management (IPM) and two variants based on organic production (controls). Higher levels of pesticide residues were found in apple fruits under conventional conditions. Fenitrothion and chlorpyrifos residues were detected frequently in apple peel at concentrations up to 0.45 and 0.77 mg kg(-1), respectively. The levels found in the whole fruits of the same samples were much lower than in peel and below the respective MRLs (0.5 mg kg(-1) for both pesticides). Measurable residues of triadimenol only, up to 0.05 mg kg(-1), concentrated in the peel, were found in the apples from IPM.

  5. Circadian rhythms and new options for novel anticancer therapies

    Directory of Open Access Journals (Sweden)

    Prosenc Zmrzljak U

    2015-01-01

    Full Text Available Ursula Prosenc ZmrzljakFaculty of Medicine, Center for Functional Genomics and Bio-Chips, Institute of Biochemistry, University of Ljubljana, Ljubljana, SloveniaAbstract: The patterns of activity/sleep, eating/fasting, etc show that our lives are under the control of an internal clock. Cancer is a systemic disease that affects sleep, feeding, and metabolism. All these processes are regulated by the circadian clock on the one hand, but on the other hand, they can serve as signals to tighten up the patient's circadian clock by robust daily routine. Usually, anticancer treatments take place in hospitals, where the patient's daily rest/activity pattern is changed. However, it has been shown that oncology patients with a disturbed circadian clock have poorer survival outcomes. The administration of different anticancer therapies can disturb the circadian cycle, but many cases show that circadian rhythms in tumors are deregulated per se. This fact can be used to plan anticancer therapies in such a manner that they will be most effective in antitumor action, but least toxic for the surrounding healthy tissue. Metabolic processes are highly regulated to prevent waste of energy and to ensure sufficient detoxification; as a consequence, xenobiotic metabolism is under tight circadian control. This gives the rationale for planning the administration of anticancer therapies in a chronomodulated manner. We review some of the potentially useful clinical praxes of anticancer therapies and discuss different possible approaches to be used in drug development and design in the future.Keywords: circadian rhythms, cancer, chronotherapy, detoxification metabolism

  6. Improvement of the Raman detection system for pesticide residues on/in fruits and vegetables

    Science.gov (United States)

    Li, Yan; Peng, Yankun; Zhai, Chen; Chao, Kuanglin; Qin, Jianwei

    2017-05-01

    Pesticide residue is one of the major challenges to fruits safety, while the traditional detection methods of pesticide residue on fruits and vegetables can't afford the demand of rapid detection in actual production because of timeconsuming. Thus rapid identification and detection methods for pesticide residue are urgently needed at present. While most Raman detection systems in the market are spot detection systems, which limits the range of application. In the study, our lab develops a Raman detection system to achieve area-scan thorough the self-developed spot detection Raman system with a control software and two devices. In the system, the scanning area is composed of many scanning spots, which means every spot needs to be detected and more time will be taken than area-scan Raman system. But lower detection limit will be achieved in this method. And some detection device is needed towards fruits and vegetables in different shape. Two detection devices are developed to detect spherical fruits and leaf vegetables. During the detection, the device will make spherical fruit rotate along its axis of symmetry, and leaf vegetables will be pressed in the test surface smoothly. The detection probe will be set to keep a proper distance to the surface of fruits and vegetables. It should make sure the laser shins on the surface of spherical fruit vertically. And two software are used to detect spherical fruits and leaf vegetables will be integrated to one, which make the operator easier to switch. Accordingly two detection devices for spherical fruits and leaf vegetables will also be portable devices to make it easier to change. In the study, a new way is developed to achieve area-scan result by spot-scan Raman detection system.

  7. Assessment of direct exposure and leaching risk from PAHs in roadway and stormwater system residuals.

    Science.gov (United States)

    Azah, Edmund; Kim, Hwidong; Townsend, Timothy

    2017-12-31

    Wastes generated from municipal cleaning activities such as street sweeping, ditch cleaning, stormwater pond maintenance, and catch basin sediment removal require appropriate management. Beneficial use of these types of waste is a good alternative to landfilling; however, there are genuine concerns about possible soil and groundwater contamination by pollutants such as polycyclic aromatic hydrocarbons (PAHs). This study assessed the potential risks associated with beneficial use of roadway and stormwater system residuals collected from 14 cities across the state of Florida, USA. Total and leachable concentrations of 16 priority PAHs in the residual samples were measured and compared to appropriate risk-based regulatory threshold values. The bioaccessibility of the PAHs found in the waste streams was also determined using in vitro gastrointestinal leaching test. Of the PAHs studied, benzo [a] pyrene measured concentrations were above appropriate risk-based regulatory threshold values for soil and groundwater, while all other detected PAHs measured concentrations were below. Benzo [a] pyrene concentration (mg/kg) in street sweepings was 1.2 times higher than residential threshold values and 6 times lower than industrial threshold values. The in vitro study found PAH bioaccessibility to range from 1.7% to 49% in six roadway and stormwater system residual samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A productivity and cost comparison of two systems for producing biomass fuel from roadside forest treatment residues

    Science.gov (United States)

    Nathaniel Anderson; Woodam Chung; Dan Loeffler; John Greg Jones

    2012-01-01

    Forest operations generate large quantities of forest biomass residues that can be used for production of bioenergy and bioproducts. However, a significant portion of recoverable residues are inaccessible to large chip vans, making use financially infeasible. New production systems must be developed to increase productivity and reduce costs to facilitate use of these...

  9. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  10. Spatial decision support system to evaluate crop residue energy potential by anaerobic digestion.

    Science.gov (United States)

    Escalante, Humberto; Castro, Liliana; Gauthier-Maradei, Paola; Rodríguez De La Vega, Reynel

    2016-11-01

    Implementing anaerobic digestion (AD) in energy production from crop residues requires development of decision tools to assess its feasibility and sustainability. A spatial decision support system (SDSS) was constructed to assist decision makers to select appropriate feedstock according to biomethanation potential, identify the most suitable location for biogas facilities, determine optimum plant capacity and supply chain, and evaluate associated risks and costs. SDSS involves a spatially explicit analysis, fuzzy multi-criteria analysis, and statistical and optimization models. The tool was validated on seven crop residues located in Santander, Colombia. For example, fique bagasse generates about 0.21millionm(3)CH4year(-1) (0.329m(3)CH4kg(-1) volatile solids) with a minimum profitable plant of about 2000tonyear(-1) and an internal rate of return of 10.5%. SDSS can be applied to evaluate other biomass resources, availability periods, and co-digestion potential. Copyright © 2016. Published by Elsevier Ltd.

  11. Dysglycemia induces abnormal circadian blood pressure variability

    Directory of Open Access Journals (Sweden)

    Kumarasamy Sivarajan

    2011-11-01

    Full Text Available Abstract Background Prediabetes (PreDM in asymptomatic adults is associated with abnormal circadian blood pressure variability (abnormal CBPV. Hypothesis Systemic inflammation and glycemia influence circadian blood pressure variability. Methods Dahl salt-sensitive (S rats (n = 19 after weaning were fed either an American (AD or a standard (SD diet. The AD (high-glycemic-index, high-fat simulated customary human diet, provided daily overabundant calories which over time lead to body weight gain. The SD (low-glycemic-index, low-fat mirrored desirable balanced human diet for maintaining body weight. Body weight and serum concentrations for fasting glucose (FG, adipokines (leptin and adiponectin, and proinflammatory cytokines [monocyte chemoattractant protein-1 (MCP-1 and tumor necrosis factor-α (TNF-α] were measured. Rats were surgically implanted with C40 transmitters and blood pressure (BP-both systolic; SBP and diastolic; DBP and heart rate (HR were recorded by telemetry every 5 minutes during both sleep (day and active (night periods. Pulse pressure (PP was calculated (PP = SBP-DBP. Results [mean(SEM]: The AD fed group displayed significant increase in body weight (after 90 days; p Conclusion These data validate our stated hypothesis that systemic inflammation and glycemia influence circadian blood pressure variability. This study, for the first time, demonstrates a cause and effect relationship between caloric excess, enhanced systemic inflammation, dysglycemia, loss of blood pressure control and abnormal CBPV. Our results provide the fundamental basis for examining the relationship between dysglycemia and perturbation of the underlying mechanisms (adipose tissue dysfunction induced local and systemic inflammation, insulin resistance and alteration of adipose tissue precursors for the renin-aldosterone-angiotensin system which generate abnormal CBPV.

  12. Molecular Mechanisms Regulating Temperature Compensation of the Circadian Clock

    Directory of Open Access Journals (Sweden)

    David M. Virshup

    2017-04-01

    Full Text Available An approximately 24-h biological timekeeping mechanism called the circadian clock is present in virtually all light-sensitive organisms from cyanobacteria to humans. The clock system regulates our sleep–wake cycle, feeding–fasting, hormonal secretion, body temperature, and many other physiological functions. Signals from the master circadian oscillator entrain peripheral clocks using a variety of neural and hormonal signals. Even centrally controlled internal temperature fluctuations can entrain the peripheral circadian clocks. But, unlike other chemical reactions, the output of the clock system remains nearly constant with fluctuations in ambient temperature, a phenomenon known as temperature compensation. In this brief review, we focus on recent advances in our understanding of the posttranslational modifications, especially a phosphoswitch mechanism controlling the stability of PER2 and its implications for the regulation of temperature compensation.

  13. Low-power implementation of polyphase filters in Quadratic Residue Number System

    DEFF Research Database (Denmark)

    Cardarilli, Gian Carlo; Re, Andrea Del; Nannarelli, Alberto

    2004-01-01

    The aim of this work is the reduction of the power dissipated in digital filters, while maintaining the timing unchanged. A polyphase filter bank in the Quadratic Residue Number System (QRNS) has been implemented and then compared, in terms of performance, area, and power dissipation...... to the implementation of a polyphase filter bank in the traditional two's complement system (TCS). The resulting implementations, designed to have the same clock rates, show that the QRNS filter is smaller and consumes less power than the TCS one....

  14. Study on grey theoretical model of passive residual heat removal system

    International Nuclear Information System (INIS)

    Zhou Tao; Yang Ruichang; Su, G.H.; Jia Dounan; Sugiyama, K.

    2004-01-01

    Natural Circulation Passive Residual Heat Removal System is treated as a Grey System by taking into account of its complexity and uncertainty of effect for factors each other. The magnitude and degree of some factors are confirmed by grey incidence analysis method; The one-one relationship of some variables is built by GM (1, 1) model; The relationship between key factor and other effect factors is built (1, 4) model. Grey model shows its more advantage of precision through comparing with multivariate model. (author)

  15. Disruption of Circadian Rhythms: A Crucial Factor in the Etiology of Depression

    Directory of Open Access Journals (Sweden)

    Roberto Salgado-Delgado

    2011-01-01

    Full Text Available Circadian factors might play a crucial role in the etiology of depression. It has been demonstrated that the disruption of circadian rhythms by lighting conditions and lifestyle predisposes individuals to a wide range of mood disorders, including impulsivity, mania and depression. Also, associated with depression, there is the impairment of circadian rhythmicity of behavioral, endocrine, and metabolic functions. Inspite of this close relationship between both processes, the complex relationship between the biological clock and the incidence of depressive symptoms is far from being understood. The efficiency and the timing of treatments based on chronotherapy (e.g., light treatment, sleep deprivation, and scheduled medication indicate that the circadian system is an essential target in the therapy of depression. The aim of the present review is to analyze the biological and clinical data that link depression with the disruption of circadian rhythms, emphasizing the contribution of circadian desynchrony. Therefore, we examine the conditions that may lead to circadian disruption of physiology and behavior as described in depressive states, and, according to this approach, we discuss therapeutic strategies aimed at treating the circadian system and depression.

  16. Purinergic Signaling in Neuron-Astrocyte Interactions, Circadian Rhythms, and Alcohol Use Disorder

    Directory of Open Access Journals (Sweden)

    Daniel Lindberg

    2018-02-01

    Full Text Available Alcohol use disorder (AUD is a debilitating condition marked by cyclic patterns of craving, use, and withdrawal. These pathological behaviors are mediated by multiple neurotransmitter systems utilizing glutamate, GABA, dopamine, ATP, and adenosine. In particular, purines such as ATP and adenosine have been demonstrated to alter the phase and function of the circadian clock and are reciprocally regulated by the clock itself. Importantly, chronic ethanol intake has been demonstrated to disrupt the molecular circadian clock and is associated with altered circadian patterns of activity and sleep. Moreover, ethanol has been demonstrated to disrupt purinergic signaling, while dysfunction of the purinergic system has been implicated in conditions of drug abuse such as AUD. In this review, we summarize our current knowledge regarding circadian disruption by ethanol, focusing on the reciprocal relationship that exists between oscillatory neurotransmission and the molecular circadian clock. In particular, we offer detailed explanations and hypotheses regarding the concerted regulation of purinergic signaling and circadian oscillations by neurons and astrocytes, and review the diverse mechanisms by which purinergic dysfuction may contribute to circadian disruption or alcohol abuse. Finally, we describe the mechanisms by which ethanol may disrupt or hijack endogenous circadian rhythms to induce the maladaptive behavioral patterns associated with AUD.

  17. Residual currents in a multiple-inlet system and the conundrum of the tidal period

    Science.gov (United States)

    Duran-Matute, Matias; Gerkema, Theo

    2015-04-01

    In multiple-inlet systems, one may find that, on average, flood dominates in some inlets, while ebb dominates in others. In that case, there is a residual flow through the system, i.e. there is a net flow if one integrates over a tidal period. Conceptually, this seems straightforward. However, to measure such a residual flow presents several difficulties. First, one needs to cover the entire cross-sections of all the inlets over a year or longer to take into account the variability due to wind. Second, the residual flow is usually much smaller than the tidal prisms and hence more uncertain in view of error bars. Third, the duration of 'the' tidal period when calculating a tidally averaged flow is not well defined. Should one take the time between alternate slack tides, or between consecutive high (or low) waters, or other options? There appears to be a fundamental ambiguity in the duration of the tidal period; here we discuss its origins. The problem of defining the tidal period seems to have received little attention in the literature, or perhaps it has not been perceived as a problem at all. One reason for this neglect may be that the focus in tidal analysis is often on the (main) individual tidal constituents, whose periods are well-defined. Indeed, the harmonic method developed by Kelvin exploits this fact, making it possible to predict high and low waters precisely by adding up the different constituents after their amplitudes and phases have been determined empirically for the location in question. The period between subsequent high (or low) waters is then simply an outcome of this method. Another reason for neglecting this problem may be that the main interest was in computing a representative quantity such as the yearly average residual flow through the inlets. For such quantities, the definition of the tidal period is not as relevant since one integrates over a much longer period. Recently, however, it has been shown, for the Western Dutch Wadden Sea, that

  18. Circadian clock and oral cancer.

    Science.gov (United States)

    Nirvani, Minou; Khuu, Cuong; Utheim, Tor Paaske; Sand, Lars Peter; Sehic, Amer

    2018-02-01

    The circadian clock is comprised of a master component situated in the hypothalamic suprachiasmatic nucleus and subordinate clock genes in almost every cell of the body. The circadian clock genes and their encoded proteins govern the organism to follow the natural signals of time, and adapt to external changes in the environment. The majority of physiological processes in mammals exhibit variable circadian rhythms, which are generated and coordinated by an oscillation in the expression of the clock genes. A number of studies have reported that alteration in the expression level of clock genes is correlated with several pathological conditions, including cancer. However, little is known about the role of clock genes in homeostasis of the oral epithelium and their disturbances in oral carcinogenesis. The present review summarizes the current state of knowledge of the implications of clock genes in oral cancer. It has been demonstrated that the development of oral squamous cell carcinoma undergoes circadian oscillation in relation to tumor volume and proliferation rate. The circadian clock gene period ( PER)1 has been associated with oral cancer pathogenesis and it is suggested that changes in the expression of PER1 may exhibit an important role in the development, invasion, and metastasis of oral squamous cell carcinoma. However, its role remains elusive and there is a need for further research in order to understand the underlying mechanisms of the clock genes in oral cancer pathogenesis.

  19. Determination of crop residues and the physical and mechanical properties of soil in different tillage systems

    Directory of Open Access Journals (Sweden)

    P Ahmadi Moghaddam

    2016-04-01

    Full Text Available Introduction: Monitoring and management of soil quality is crucial for sustaining soil function in ecosystem. Tillage is one of the management operations that drastically affect soil physical quality. Conservation tillage methods are one of the efficient solutions in agriculture to reduce the soil erosion, air pollution, energy consumption, and the costs, if there is a proper management on the crop residues. One of the serious problems in agriculture is soil erosion which is rapidly increased in the recent decades as the intensity of tillage increases. This phenomenon occurs more in sloping lands or in the fields which are lacking from crop residues and organic materials. The conservation tillage has an important role in minimizing soil erosion and developing the quality of soil. Hence, it has attracted the attention of more researchers and farmers in the recent years. Materials and Methods: In this study, the effect of different tillage methods has been investigated on the crop residues, mechanical resistance of soil, and the stability of aggregates. This research was performed on the agricultural fields of Urmia University, located in Nazloo zone in 2012. Wheat and barley were planted in these fields, consecutively. The soil texture of these fields was loamy clay and the factorial experiments were done in a completely randomized block design. In this study, effect of three tillage systems including tillage with moldboard (conventional tillage, tillage with disk plow (reduced tillage, chisel plow (minimum tillage and control treatment on some soil physical properties was investigated. Depth is second factor that was investigated in three levels including 0-60, 60-140, and 140-200 mm. Moreover, the effect of different percentages of crop residues on the rolling resistance of non-driving wheels was studied in a soil bin. The contents of crop residues have been measured by using the linear transects and image processing methods. In the linear

  20. Natural selection against a circadian clock gene mutation in mice.

    Science.gov (United States)

    Spoelstra, Kamiel; Wikelski, Martin; Daan, Serge; Loudon, Andrew S I; Hau, Michaela

    2016-01-19

    Circadian rhythms with an endogenous period close to or equal to the natural light-dark cycle are considered evolutionarily adaptive ("circadian resonance hypothesis"). Despite remarkable insight into the molecular mechanisms driving circadian cycles, this hypothesis has not been tested under natural conditions for any eukaryotic organism. We tested this hypothesis in mice bearing a short-period mutation in the enzyme casein kinase 1ε (tau mutation), which accelerates free-running circadian cycles. We compared daily activity (feeding) rhythms, survivorship, and reproduction in six replicate populations in outdoor experimental enclosures, established with wild-type, heterozygous, and homozygous mice in a Mendelian ratio. In the release cohort, survival was reduced in the homozygote mutant mice, revealing strong selection against short-period genotypes. Over the course of 14 mo, the relative frequency of the tau allele dropped from initial parity to 20%. Adult survival and recruitment of juveniles into the population contributed approximately equally to the selection for wild-type alleles. The expression of activity during daytime varied throughout the experiment and was significantly increased by the tau mutation. The strong selection against the short-period tau allele observed here contrasts with earlier studies showing absence of selection against a Period 2 (Per2) mutation, which disrupts internal clock function, but does not change period length. These findings are consistent with, and predicted by the theory that resonance of the circadian system plays an important role in individual fitness.

  1. Circadian Plasticity in the Brain of Insects and Rodents

    Directory of Open Access Journals (Sweden)

    Wojciech Krzeptowski

    2018-05-01

    Full Text Available In both vertebrate and invertebrate brains, neurons, glial cells and synapses are plastic, which means that the physiology and structure of these components are modified in response to internal and external stimuli during development and in mature brains. The term plasticity has been introduced in the last century to describe experience-dependent changes in synapse strength and number. These changes result from local functional and morphological synapse modifications; however, these modifications also occur more commonly in pre- and postsynaptic neurons. As a result, neuron morphology and neuronal networks are constantly modified during the life of animals and humans in response to different stimuli. Nevertheless, it has been discovered in flies and mammals that the number of synapses and size and shape of neurons also oscillate during the day. In most cases, these rhythms are circadian since they are generated by endogenous circadian clocks; however, some rhythmic changes in neuron morphology and synapse number and structure are controlled directly by environmental cues or by both external cues and circadian clocks. When the circadian clock is involved in generating cyclic changes in the nervous system, this type of plasticity is called circadian plasticity. It seems to be important in processing sensory information, in learning and in memory. Disruption of the clock may affect major brain functions.

  2. Investigation of passive residual heat removal system for VVERs: Effects of finned type heat exchanger tubes

    International Nuclear Information System (INIS)

    Ayhan, Hüseyin; Sökmen, Cemal Niyazi

    2016-01-01

    Highlights: • Performance of passive residual heat removal system (PRHRS) of VVER type nuclear power plants is investigated. • Unit heat exchanger of PRHRS is designed to reject 4 MW heat amount from reactor via steam generator. • This study shows that decay heat can be rejected by 16 heat exchangers of PRHRS without any operator actions. - Abstract: After nuclear reactor shutdown, decay heat generation continues in the reactor core and it has the possibility to cause a severe accident. This residual heat has to be removed from the core sufficiently. In Water-Water Energetic Reactors (WWER) or VVERs, passive residual heat removal system is designed to remove decay heat after reactor shutdown. This system does not need any power operation, since ambient air is used as the cooling fluid in heat exchanger. The steam that is generated in the steam generators due to the heat released in the reactor core condenses and rejects its heat to the ambient air within this heat exchanger. The condensed liquid is returned back to the steam generator. The motion of the cooling medium occurs due to natural circulation. In the presented study, the original geometric design of passive residual heat removal system of VVER type nuclear power plants is introduced. The performance of this system is investigated. In the previous study, geometric design parameters for this system was determined for plain tubes of heat exchanger. Heat exchanger tubes were positioned as a helical in the previous study. With the knowledge of enhancing heat transfer using finned surfaces, geometrical design is modified in presented study. Circular type fin structures (having rectangular cross-section) are added to the outer surface of heat exchanger tubes. In the present heat exchanger model, tubes are positioned as a staggered bank. As the fin parameters, fin thickness, fin radius and total fin number are investigated in this study. Results are compared with the one obtained with plane tube (in tube

  3. Control system of an anaerobia reactor used in the treatment of the Industrial residual waters

    International Nuclear Information System (INIS)

    Duque, Mauricio; Giraldo, Eugenio; Bello Frank

    1995-01-01

    The technology of the anaerobia digestion, has had a wide acceptance in the Colombian means for the treatment of industrial residual waters, especially for the economic advantages that it present and the good purification results. The technology of the anaerobia digestion for the treatment of residual waters, is based in the conversion of the organic matter present in the polluted waters, in methane and carbon dioxide. These two gases are removed of the reactor by means of special structures of gathering. Microorganisms that are sensitive to the changes of the pH mediate the conversion of the organic matter to CH4 and CO2. Therefore, the control on the pH is necessary for a correct behavior of the reactor. At the moment many industries are implementing plans of contamination control, that involve treatment of residual waters for means anaerobia. The present investigation is part of a wide work program in the technology of the anaerobia digestion. It is looked for to develop a monitored system and automatic control of reactors discharge anaerobia appraises, in a combined effort among the departments of Civil and Electric Engineering of the Andes University

  4. A High-Frequency Eddy Current Inspection System and Its Application to the Residual Stress Characterization

    International Nuclear Information System (INIS)

    Nakagawa, N.; Lee, C.; Shen, Y.

    2006-01-01

    This paper reports on an on-going project toward developing electromagnetic residual-stress characterization method. Specifically, we present recent work on an eddy current technique and model-based inversion method, specific to nickel-based superalloys. In our approach, we treat residual stress measurements essentially as a 'layer-substrate' problem (a shot-peened layer on an alloy substrate), to which the swept-frequency EC technique is applicable. To this end, a high-sensitivity eddy current system with operating frequency up to 50MHz has been recently developed and validated. We present a description of our instrumentation that includes proprietary probes fabricated by the PCB technology, and laboratory-grade instruments under software control. The paper also describes the experimental procedure for performance studies, supported by preliminary data that distinguish clearly between surfaces before and after shot-peening for nickel-based alloys. In addition, we present forward and inverse model validations which will determine their reliability in the subsequent use in model-based residual stress profile inversion

  5. Ball milled bauxite residue as a reinforcing filler in phosphate-based intumescent system

    Directory of Open Access Journals (Sweden)

    Adiat Ibironke Arogundade

    2018-01-01

    Full Text Available Bauxite residue (BR is an alumina refinery waste with a global disposal problem. Of the 120 MT generated annually, only 3 MT is disposed via utilization. One of the significant challenges to sustainable utilization has been found to be the cost of processing. In this work, using ball milling, we achieved material modification of bauxite residue. Spectrometric imaging with FESEM showed the transformation from an aggregate structure to nano, platy particulates, leading to particle size homogeneity. BET analysis showed surface area was increased by 23%, while pH was reduced from 10.8 to 9.1 due to collapsing of the hydroxyl surface by the fracturing action of the ball mill. Incorporation of this into a phosphate-based fire retardant, intumescent formulation led to improved material dispersion and the formation of reinforcing heat shielding char nodules. XRD revealed the formation of ceramic metal phosphates which acted as an additional heat sink to the intumescent system, thereby reducing char oxidation and heat transfer to the substrate. Steel substrate temperature from a Bunsen burner test reduced by 33%. Therefore, ball milling can serve as a simple, low-cost processing route for the reuse of bauxite residue in intumescent composites.

  6. Environmental disruption of the circadian clock leads to altered sleep and immune responses in mouse.

    Science.gov (United States)

    Phillips, Derrick J; Savenkova, Marina I; Karatsoreos, Ilia N

    2015-07-01

    In mammals, one of the most salient outputs of the circadian (daily) clock is the timing of the sleep-wake cycle. Modern industrialized society has led to a fundamental breakdown in the relationship between our endogenous timekeeping systems and the solar day, disrupting normal circadian rhythms. We have argued that disrupted circadian rhythms could lead to changes in allostatic load, and the capacity of organisms to respond to other environmental challenges. In this set of studies, we apply a model of circadian disruption characterized in our lab in which mice are housed in a 20h long day, with 10h of light and 10h of darkness. We explored the effects of this environmental disruption on sleep patterns, to establish if this model results in marked sleep deprivation. Given the interaction between circadian, sleep, and immune systems, we further probed if our model of circadian disruption also alters the innate immune response to peripheral bacterial endotoxin challenge. Our results demonstrate that this model of circadian disruption does not lead to marked sleep deprivation, but instead affects the timing and quality of sleep. We also show that while circadian disruption does not lead to basal changes in the immune markers we explored, the immune response is affected, both in the brain and the periphery. Together, our findings further strengthen the important role of the circadian timing system in sleep regulation and immune responses, and provide evidence that disrupting the circadian clock increases vulnerability to further environmental stressors, including immunological challenges. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Circadian timing of food intake contributes to weight gain.

    Science.gov (United States)

    Arble, Deanna M; Bass, Joseph; Laposky, Aaron D; Vitaterna, Martha H; Turek, Fred W

    2009-11-01

    Studies of body weight regulation have focused almost entirely on caloric intake and energy expenditure. However, a number of recent studies in animals linking energy regulation and the circadian clock at the molecular, physiological, and behavioral levels raise the possibility that the timing of food intake itself may play a significant role in weight gain. The present study focused on the role of the circadian phase of food consumption in weight gain. We provide evidence that nocturnal mice fed a high-fat diet only during the 12-h light phase gain significantly more weight than mice fed only during the 12-h dark phase. A better understanding of the role of the circadian system for weight gain could have important implications for developing new therapeutic strategies for combating the obesity epidemic facing the human population today.

  8. Design Status of the Capillary Brine Residual in Containment Water Recovery System

    Science.gov (United States)

    Sargusingh, Miriam J.; Callahan, Michael R.; Garison, John; Houng, Benjamin; Weislogel, Mark M.

    2016-01-01

    One of the goals of the AES Life Support System (LSS) Project is to achieve 98% water loop closure for long duration human exploration missions beyond low Earth orbit. To meet this objective, the AES LSS Project is developing technologies to recover water from wastewater brine; highly concentrated waste products generated from a primary water recovery system. The state of the art system used aboard the International Space Station (ISS) has the potential to recover up to 85% water from unine wastewater, leaving a significant amounts of water in the waste brine, the recovery of which is critical technology gap that must be filled in order to enable long duration human exploration. Recovering water from the urine wastewater brine is complicated by the concentration of solids as water is removed from the brine, and the concentration of the corrosive, toxic chemicals used to stabilize the urine which fouls and degrades water processing hardware, and poses a hazard to operators and crew. Brine Residual in Containment (BRIC) is focused on solids management through a process of "in-place" drying - the drying of brines within the container used for final disposal. Application of in-place drying has the potential to improve the safety and reliability of the system by reducing the exposure to curew and hardware to the problematic brine residual. Through a collaboration between the NASA Johnson Space Center and Portland Status University, a novel water recovery system was developed that utilizes containment geometry to support passive capillary flow and static phase separation allowing free surface evaporation to take place in a microgravity environment. A notional design for an ISS demonstration system was developed. This paper describes the testing performed to characterize the performance of the system as well as the status of the system level design.

  9. Comparative Analysis of Vertebrate Diurnal/Circadian Transcriptomes.

    Directory of Open Access Journals (Sweden)

    Greg Boyle

    Full Text Available From photosynthetic bacteria to mammals, the circadian clock evolved to track diurnal rhythms and enable organisms to anticipate daily recurring changes such as temperature and light. It orchestrates a broad spectrum of physiology such as the sleep/wake and eating/fasting cycles. While we have made tremendous advances in our understanding of the molecular details of the circadian clock mechanism and how it is synchronized with the environment, we still have rudimentary knowledge regarding its connection to help regulate diurnal physiology. One potential reason is the sheer size of the output network. Diurnal/circadian transcriptomic studies are reporting that around 10% of the expressed genome is rhythmically controlled. Zebrafish is an important model system for the study of the core circadian mechanism in vertebrate. As Zebrafish share more than 70% of its genes with human, it could also be an additional model in addition to rodent for exploring the diurnal/circadian output with potential for translational relevance. Here we performed comparative diurnal/circadian transcriptome analysis with established mouse liver and other tissue datasets. First, by combining liver tissue sampling in a 48h time series, transcription profiling using oligonucleotide arrays and bioinformatics analysis, we profiled rhythmic transcripts and identified 2609 rhythmic genes. The comparative analysis revealed interesting features of the output network regarding number of rhythmic genes, proportion of tissue specific genes and the extent of transcription factor family expression. Undoubtedly, the Zebrafish model system will help identify new vertebrate outputs and their regulators and provides leads for further characterization of the diurnal cis-regulatory network.

  10. Circadian clock dysfunction and psychiatric disease: could fruit flies have a say?

    Directory of Open Access Journals (Sweden)

    Mauro Agostino Zordan

    2015-04-01

    Full Text Available There is evidence of a link between the circadian system and psychiatric diseases. Studies in humans and mammals suggest that environmental and/or genetic disruption of the circadian system lead to an increased liability to psychiatric disease. Disruption of clock genes and/or the clock network might be related to the etiology of these pathologies; also, some genes, known for their circadian clock functions, might be associated to mental illnesses through clock-independent pleiotropy. Here we examine the features which we believe make Drosophila melanogaster a model apt to study the role of the circadian clock in psychiatric disease. Despite differences in the organization of the clock system, the molecular architecture of the Drosophila and mammalian circadian oscillators are comparable and many components are evolutionarily related. In addition, Drosophila has a rather complex nervous system, which shares much at the cell and neurobiological level with humans, i.e. a tripartite brain, the main neurotransmitter systems, and behavioral traits: circadian behavior, learning and memory, motivation, addiction, social behavior. There is evidence that the Drosophila brain shares some homologies with the vertebrate cerebellum, basal ganglia and hypothalamus-pituitary-adrenal axis, the dysfunctions of which have been tied to mental illness. We discuss Drosophila in comparison to mammals with reference to the: organization of the brain and neurotransmitter systems; architecture of the circadian clock; clock-controlled behaviors. We sum up current knowledge on behavioral endophenotypes which are amenable to modeling in flies, such as defects involving sleep, cognition, or social interactions and discuss the relationship of the circadian system to these traits. Finally, we consider if Drosophila could be a valuable asset to understand the relationship between circadian clock malfunction and psychiatric disease.

  11. Circadian Clock Dysfunction and Psychiatric Disease: Could Fruit Flies have a Say?

    Science.gov (United States)

    Zordan, Mauro Agostino; Sandrelli, Federica

    2015-01-01

    There is evidence of a link between the circadian system and psychiatric diseases. Studies in humans and mammals suggest that environmental and/or genetic disruption of the circadian system leads to an increased liability to psychiatric disease. Disruption of clock genes and/or the clock network might be related to the etiology of these pathologies; also, some genes, known for their circadian clock functions, might be associated to mental illnesses through clock-independent pleiotropy. Here, we examine the features which we believe make Drosophila melanogaster a model apt to study the role of the circadian clock in psychiatric disease. Despite differences in the organization of the clock system, the molecular architecture of the Drosophila and mammalian circadian oscillators are comparable and many components are evolutionarily related. In addition, Drosophila has a rather complex nervous system, which shares much at the cell and neurobiological level with humans, i.e., a tripartite brain, the main neurotransmitter systems, and behavioral traits: circadian behavior, learning and memory, motivation, addiction, social behavior. There is evidence that the Drosophila brain shares some homologies with the vertebrate cerebellum, basal ganglia, and hypothalamus-pituitary-adrenal axis, the dysfunctions of which have been tied to mental illness. We discuss Drosophila in comparison to mammals with reference to the: organization of the brain and neurotransmitter systems; architecture of the circadian clock; clock-controlled behaviors. We sum up current knowledge on behavioral endophenotypes, which are amenable to modeling in flies, such as defects involving sleep, cognition, or social interactions, and discuss the relationship of the circadian system to these traits. Finally, we consider if Drosophila could be a valuable asset to understand the relationship between circadian clock malfunction and psychiatric disease.

  12. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, G.M. [Commissariat a l`Energie Atomique, Saint-Paul-Lez-Durance (France)

    1995-09-01

    In the framework of research on diversified means for removing residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system). This system consists of integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: such as independent from the state of the loops, low volume of water in the primary circuit, compatibility with either a passive or an active operation mode, and compatibility with any other decay heat removal systems. This paper presents an evaluation of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of any another system. The results of this evaluation show the potential interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system and no need for the use of a high pressure safety injection system.

  13. Design Status of the Capillary Brine Residual in Containment Water Recovery System

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2016-01-01

    One of the goals of the AES Life Support System (LSS) Project is to achieve 98% water loop closure for long duration human exploration missions beyond low Earth orbit. To meet this objective, the AES LSS Project is developing technologies to recover water from wastewater brine; highly concentrated waste products generated from a primary water recovery system. The state of the art system used aboard the International Space Station (ISS) has the potential to recover up to 85% water from unine wastewater, leaving a significant amounts of water in the waste brine, the recovery of which is a critical technology gap that must be filled in order to enable long duration human exploration. Recovering water from the urine wastewater brine is complicated by the concentration of solids as water is removed from the brine, and the concentration of the corrosive, toxic chemicals used to stabilize the urine which fouls and degrades water processing hardware, and poses a hazard to operators and crew. Brine Residual in Containment (BRIC) is focused on solids management through a process of "in-place" drying - the drying of brines within the container used for final disposal. Application of in-place drying has the potential to improve the safety and reliability of the system by reducing the exposure to crew and hardware to the problematic brine residual. Through a collaboration between the NASA Johnson Space Center and Portland Status University, a novel water recovery system was developed that utilizes containment geometry to support passive capillary flow and static phase separation allowing free surface evaporation to take place in a microgravity environment. A notional design for an ISS demonstration system was developed. This paper describes the concept for the system level design.

  14. Metabolism and the Circadian Clock Converge

    Science.gov (United States)

    Eckel-Mahan, Kristin

    2013-01-01

    Circadian rhythms occur in almost all species and control vital aspects of our physiology, from sleeping and waking to neurotransmitter secretion and cellular metabolism. Epidemiological studies from recent decades have supported a unique role for circadian rhythm in metabolism. As evidenced by individuals working night or rotating shifts, but also by rodent models of circadian arrhythmia, disruption of the circadian cycle is strongly associated with metabolic imbalance. Some genetically engineered mouse models of circadian rhythmicity are obese and show hallmark signs of the metabolic syndrome. Whether these phenotypes are due to the loss of distinct circadian clock genes within a specific tissue versus the disruption of rhythmic physiological activities (such as eating and sleeping) remains a cynosure within the fields of chronobiology and metabolism. Becoming more apparent is that from metabolites to transcription factors, the circadian clock interfaces with metabolism in numerous ways that are essential for maintaining metabolic homeostasis. PMID:23303907

  15. A photoelastic measurement system for residual stress analysis in scintillating crystals by conoscopic imaging

    Science.gov (United States)

    Montalto, L.; Paone, N.; Scalise, L.; Rinaldi, D.

    2015-06-01

    The assessment of the stress state of scintillating crystals is an important issue for producers as well as users of such materials, because residual stress may arise during growth process. In this paper, a measurement system, based on the use of a photoelastic, conoscopic optical setup, is proposed for the assessment of stress state in scintillating crystals. Local stress values can be measured on the crystal in order to observe their spatial distribution. With the proposed system, it is possible to vary the dimensions of the inspected measurement volume. It has been validated with reference to a known stress state induced in a birefringent crystal sample and it has been tested for the case of loaded and unloaded samples, showing sub-millimetric spatial resolution and stress uncertainty ≤0.25 MPa. The proposed measurement system is a valid method for the inspection of scintillating crystals required by producers and users of such materials.

  16. Research on sleep, circadian rhythms and aging - Applications to manned spaceflight

    Science.gov (United States)

    Czeisler, Charles A.; Chiasera, August J.; Duffy, Jeanne F.

    1991-01-01

    Disorders of sleep and circadian rhythmicity are characteristic of both advancing age and manned spaceflight. Sleep fragmentation, reduced nocturnal sleep tendency and sleep efficiency, reduced daytime alertness, and increased daytime napping are common to both of these conditions. Recent research on the pathophysiology and treatment of disrupted sleep in older people has led to a better understanding of how the human circadian pacemaker regulates the timing of the daily sleep-wake cycle and how it responds to the periodic changes in the light-dark cycle to which we are ordinarily exposed. These findings have led to new treatments for some of the sleep disorders common to older individuals, using carefully timed exposure to bright light and darkness to manipulate the phase and/or amplitude of the circadian timing system. These insights and treatment approaches have direct applications in the design of countermeasures allowing astronauts to overcome some of the challenges which manned spaceflight poses for the human circadian timing system. We have conducted an operational feasibility study on the use of scheduled exposure to bright light and darkness prior to launch in order to facilitate adaptation of the circadian system of a NASA Space Shuttle crew to the altered sleep-wake schedule required for their mission. The results of this study illustrate how an understanding of the properties of the human circadian timing system and the consequences of circadian disruption can be applied to manned spaceflight.

  17. Systemic Associations with Residual Subretinal Fluid after Ranibizumab in Diabetic Macular Edema

    Directory of Open Access Journals (Sweden)

    Meng-Ju Tsai

    2017-01-01

    Full Text Available Purpose. To investigate the impact of systemic diseases on the occurrence of subretinal fluid (SRF in diabetic macular edema (DME and prognostic factors for residual SRF following three consecutive monthly intravitreal ranibizumab. Methods. Ninety-seven eyes from 68 patients with DME who completed 3 consecutive monthly injections of ranibizumab were enrolled. Systemic parameters mainly included chronic kidney disease (CKD, hypertension, HbA1c, and insulin dependence. Renal parameters for CKD were serum creatinine, estimated glomerular filtration rate (eGFR, and serum albumin. Ocular factors were baseline central macular thickness (CMT, severity of diabetic retinopathy (DR, and status of panretinal photocoagulation (PRP. Results. Chronic kidney disease had significant correlation with baseline SRF (R=0.397, p<0.001 after partial correlation with adjustment for age and DR severity. As for CKD, lower serum albumin, but not eGFR or serum creatinine, was associated with baseline presence of SRF (p=0.026, p=0.08 and p=0.53, resp., after adjustment for age and DR severity. Overall, lower eGFR and lower HbA1c values, contrary to popular belief, predicted the presence of residual SRF following intravitreal injections (p=0.016 and p<0.001, resp.. Conclusions. Tight sugar control and poorer baseline kidney function may slow the resorption of SRF after anti-VEGF injections in patients with DME in the short term.

  18. Circadian rhythm in salivary melatonin in narcoleptic patiens

    Czech Academy of Sciences Publication Activity Database

    Blažejová, K.; Illnerová, Helena; Hájek, Ivan; Nevšímalová, S.

    2008-01-01

    Roč. 437, č. 2 (2008), s. 162-164 ISSN 0304-3940 R&D Projects: GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : narcolepsy * circadian system * melatonin Subject RIV: FH - Neurology Impact factor: 2.200, year: 2008

  19. Living by the clock: the circadian pacemaker in older people.

    NARCIS (Netherlands)

    Hofman, M.A.; Swaab, D.F.

    2006-01-01

    The suprachiasmatic nucleus (SCN) of the hypothalamus is considered to be a critical component of a neural oscillator system implicated in the timing of a wide variety of biological processes. The circadian cycles established by this biological clock occur throughout nature and have a period of

  20. Living by the clock: the circadian pacemaker in older people

    NARCIS (Netherlands)

    Hofman, Michel A.; Swaab, Dick F.

    2006-01-01

    The suprachiasmatic nucleus (SCN) of the hypothalamus is considered to be a critical component of a neural oscillator system implicated in the timing of a wide variety of biological processes. The circadian cycles established by this biological clock occur throughout nature and have a period of

  1. is pupation height affected by circadian organization in Drosophila ...

    Indian Academy of Sciences (India)

    Unknown

    and reproduction related events that constitute the life- history of an .... of light are not perceived by the Drosophila circadian system. (Chandrashekaran et al. 1973) ..... J. Insect. Physiol. 13, 1547–1568. Rizki M. T. M. and Davis C. G. Jr. 1953 Light as an ecological determinant of interspecific competition between D. willistoni.

  2. Melatonin, Light and Circadian Cycles

    Science.gov (United States)

    1989-12-25

    bifida occulta , and sarcoidosis, all show loss of the melatonin circadian rhythm, with psoriasis vulgaris, spina bifida occulta , and sarcoidosis...autonomic neuro- pathy show decreased nocturnal melatonin (Checkley and Palazidou, 1988). Klinefelter’s syndrome, Turners syndrome, psoriasis vulgaris, spina

  3. ADHD, circadian rhythms and seasonality

    NARCIS (Netherlands)

    Wynchank, Dora S.; Bijlenga, Denise; Lamers, Femke; Bron, Tannetje I.; Winthorst, Wim H.; Vogel, Suzan W.; Penninx, Brenda W.; Beekman, Aartjan T.; Kooij, J. Sandra

    2016-01-01

    Objective: We evaluated whether the association between Adult Attention-Deficit/Hyperactivity Disorder (ADHD) and Seasonal Affective Disorder (SAD) was mediated by the circadian rhythm. Method: Data of 2239 persons from the Netherlands Study of Depression and Anxiety (NESDA) were used. Two groups

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

    Science.gov (United States)

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

    1998-01-01

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

  5. Disrupting circadian homeostasis of sympathetic signaling promotes tumor development in mice.

    Directory of Open Access Journals (Sweden)

    Susie Lee

    2010-06-01

    Full Text Available Cell proliferation in all rapidly renewing mammalian tissues follows a circadian rhythm that is often disrupted in advanced-stage tumors. Epidemiologic studies have revealed a clear link between disruption of circadian rhythms and cancer development in humans. Mice lacking the circadian genes Period1 and 2 (Per or Cryptochrome1 and 2 (Cry are deficient in cell cycle regulation and Per2 mutant mice are cancer-prone. However, it remains unclear how circadian rhythm in cell proliferation is generated in vivo and why disruption of circadian rhythm may lead to tumorigenesis.Mice lacking Per1 and 2, Cry1 and 2, or one copy of Bmal1, all show increased spontaneous and radiation-induced tumor development. The neoplastic growth of Per-mutant somatic cells is not controlled cell-autonomously but is dependent upon extracellular mitogenic signals. Among the circadian output pathways, the rhythmic sympathetic signaling plays a key role in the central-peripheral timing mechanism that simultaneously activates the cell cycle clock via AP1-controlled Myc induction and p53 via peripheral clock-controlled ATM activation. Jet-lag promptly desynchronizes the central clock-SNS-peripheral clock axis, abolishes the peripheral clock-dependent ATM activation, and activates myc oncogenic potential, leading to tumor development in the same organ systems in wild-type and circadian gene-mutant mice.Tumor suppression in vivo is a clock-controlled physiological function. The central circadian clock paces extracellular mitogenic signals that drive peripheral clock-controlled expression of key cell cycle and tumor suppressor genes to generate a circadian rhythm in cell proliferation. Frequent disruption of circadian rhythm is an important tumor promoting factor.

  6. Florfenicol residues in rainbow trout after oral dosing in recirculating and flow-through culture systems.

    Science.gov (United States)

    Meinertz, J R; Hess, K R; Bernardy, J A; Gaikowski, M P; Whitsel, M; Endris, R G

    2014-12-01

    Aquaflor is a feed premix for fish containing the broad spectrum antibacterial agent florfenicol (FFC) incorporated at a ratio of 50% (w/w). To enhance the effectiveness of FFC for salmonids infected with certain isolates of Flavobacterium psychrophilum causing cold water disease, the FFC dose must be increased from the standard 10 mg·kg⁻¹ body weight (BW)·d⁻¹ for 10 consecutive days. A residue depletion study was conducted to determine whether FFC residues remaining in the fillet tissue after treating fish at an increased dose would be safe for human consumption. Groups of Rainbow Trout Oncorhynchus mykiss (total n = 144; weight range, 126-617 g) were treated with FFC at 20 mg·kg⁻¹ BW·d⁻¹ for 10 d in a flow-through system (FTS) and a recirculating aquaculture system (RAS) each with a water temperature of ∼13°C. The two-tank RAS included a nontreated tank containing 77 fish. Fish were taken from each tank (treated tank, n = 16; nontreated tank, n = 8) at 6, 12, 24, 48, 72, 120, 240, 360, and 480 h posttreatment. Florfenicol amine (FFA) concentrations (the FFC marker residue) in skin-on fillets from treated fish were greatest at 12 h posttreatment (11.58 μg/g) in the RAS and were greatest at 6 h posttreatment (11.09 μg/g) in the FTS. The half-lives for FFA in skin-on fillets from the RAS and FTS were 20.3 and 19.7 h, respectively. Assimilation of FFC residues in the fillets of nontreated fish sharing the RAS with FFC-treated fish was minimal. Florfenicol water concentrations peaked in the RAS-treated tank and nontreated tanks at 10 h (453 μg/L) and 11 h (442 μg/L) posttreatment, respectively. Monitoring of nitrite concentrations throughout the study indicated the nitrogen oxidation efficiency of the RAS biofilter was minimally impacted by the FFC treatment.

  7. Florfenicol residues in Rainbow Trout after oral dosing in recirculating and flow-through culture systems

    Science.gov (United States)

    Meinertz, Jeffery R.; Hess, Karina R.; Bernady, Jeffry A.; Gaikowski, M. P.; Whitsel, Melissa; Endris, R. G.

    2014-01-01

    Aquaflor is a feed premix for fish containing the broad spectrum antibacterial agent florfenicol (FFC) incorporated at a ratio of 50% (w/w). To enhance the effectiveness of FFC for salmonids infected with certain isolates of Flavobacterium psychrophilum causing coldwater disease, the FFC dose must be increased from the standard 10 mg·kg−1 body weight (BW)·d−1 for 10 consecutive days. A residue depletion study was conducted to determine whether FFC residues remaining in the fillet tissue after treating fish at an increased dose would be safe for human consumption. Groups of Rainbow Trout Oncorhynchus mykiss (total n = 144; weight range, 126–617 g) were treated with FFC at 20 mg·kg−1 BW·d−1 for 10 d in a flow-through system (FTS) and a recirculating aquaculture system (RAS) each with a water temperature of ∼13°C. The two-tank RAS included a nontreated tank containing 77 fish. Fish were taken from each tank (treated tank, n = 16; nontreated tank, n = 8) at 6, 12, 24, 48, 72, 120, 240, 360, and 480 h posttreatment. Florfenicol amine (FFA) concentrations (the FFC marker residue) in skin-on fillets from treated fish were greatest at 12 h posttreatment (11.58 μg/g) in the RAS and were greatest at 6 h posttreatment (11.09 μg/g) in the FTS. The half-lives for FFA in skin-on fillets from the RAS and FTS were 20.3 and 19.7 h, respectively. Assimilation of FFC residues in the fillets of nontreated fish sharing the RAS with FFC-treated fish was minimal. Florfenicol water concentrations peaked in the RAS-treated tank and nontreated tanks at 10 h (453 μg/L) and 11 h (442 μg/L) posttreatment, respectively. Monitoring of nitrite concentrations throughout the study indicated the nitrogen oxidation efficiency of the RAS biofilter was minimally impacted by the FFC treatment.

  8. Ischemic stroke destabilizes circadian rhythms

    Directory of Open Access Journals (Sweden)

    Borjigin Jimo

    2008-10-01

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

  9. The circadian rhythm of core body temperature (Part I: The use of modern telemetry systems to monitor core body temperature variability

    Directory of Open Access Journals (Sweden)

    Słomko Joanna

    2016-06-01

    Full Text Available The best known daily rhythms in humans include: the sleep-wake rhythm, the circadian core body temperature variability, daily fluctuations in arterial blood pressure and heartbeat frequency, and daily changes in hormone secretion: e.g. melatonin, cortisol, growth hormone, prolactin. The core body temperature in humans has a characteristic sinusoidal course, with the maximum value occurring between 3:00-5:00 pm and the minimum between 3:00-5:00 am. Analysis of literature indicates that the obtained results concerning core body temperature are to a large extent influenced by the type of method applied in the measurement. Depending on test protocols, we may apply various methodologies to measuring core body temperature. One of the newest methods of measuring internal and external body temperature consists in the utilisation of remote temperature sensors transmitting the obtained value via a radio signal. The advantages of this method includes the ability to perform: continuous core temperature measurement, observe dynamic changes in core body temperature occurring in circadian rhythm and the repeatability and credibility of the obtained results, which is presented in numerous scientific reports.

  10. Implications of disturbances in circadian rhythms for cardiovascular health: A new frontier in free radical biology.

    Science.gov (United States)

    Khaper, Neelam; Bailey, Craig D C; Ghugre, Nilesh R; Reitz, Cristine; Awosanmi, Zikra; Waines, Ryan; Martino, Tami A

    2017-11-13

    Cell autonomous circadian "clock" mechanisms are present in virtually every organ, and generate daily rhythms that are important for normal physiology. This is especially relevant to the cardiovascular system, for example the circadian mechanism orchestrates rhythms in heart rate, blood pressure, cardiac contractility, metabolism, gene and protein abundance over the 24-h day and night cycles. Conversely, disturbing circadian rhythms (e.g. via shift work, sleep disorders) increases cardiovascular disease risk, and exacerbates cardiac remodelling and worsens outcome. Notably, reactive oxygen species (ROS) are important contributors to heart disease, especially the pathophysiologic damage that occurs after myocardial infarction (MI, heart attack). However, little is known about how the circadian mechanism, or rhythm desynchrony, is involved in these key pathologic stress responses. This review summarizes the current knowledge on circadian rhythms in the cardiovascular system, and the implications of rhythm disturbances for cardiovascular health. Furthermore, we highlight how free radical biology coincides with the pathogenesis of myocardial repair and remodelling after MI, and indicate a role for the circadian system in the oxidative stress pathways in the heart and brain after MI. This fusion of circadian biology with cardiac oxidative stress pathways is novel, and offers enormous potential for improving our understanding and treatment of heart disease. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Human Gut Bacteria Are Sensitive to Melatonin and Express Endogenous Circadian Rhythmicity.

    Directory of Open Access Journals (Sweden)

    Jiffin K Paulose

    Full Text Available Circadian rhythms are fundamental properties of most eukaryotes, but evidence of biological clocks that drive these rhythms in prokaryotes has been restricted to Cyanobacteria. In vertebrates, the gastrointestinal system expresses circadian patterns of gene expression, motility and secretion in vivo and in vitro, and recent studies suggest that the enteric microbiome is regulated by the host's circadian clock. However, it is not clear how the host's clock regulates the microbiome. Here, we demonstrate at least one species of commensal bacterium from the human gastrointestinal system, Enterobacter aerogenes, is sensitive to the neurohormone melatonin, which is secreted into the gastrointestinal lumen, and expresses circadian patterns of swarming and motility. Melatonin specifically increases the magnitude of swarming in cultures of E. aerogenes, but not in Escherichia coli or Klebsiella pneumoniae. The swarming appears to occur daily, and transformation of E. aerogenes with a flagellar motor-protein driven lux plasmid confirms a temperature-compensated circadian rhythm of luciferase activity, which is synchronized in the presence of melatonin. Altogether, these data demonstrate a circadian clock in a non-cyanobacterial prokaryote and suggest the human circadian system may regulate its microbiome through the entrainment of bacterial clocks.

  12. Developing an Integrated Model Framework for the Assessment of Sustainable Agricultural Residue Removal Limits for Bioenergy Systems

    Energy Technology Data Exchange (ETDEWEB)

    David Muth, Jr.; Jared Abodeely; Richard Nelson; Douglas McCorkle; Joshua Koch; Kenneth Bryden

    2011-08-01

    Agricultural residues have significant potential as a feedstock for bioenergy production, but removing these residues can have negative impacts on soil health. Models and datasets that can support decisions about sustainable agricultural residue removal are available; however, no tools currently exist capable of simultaneously addressing all environmental factors that can limit availability of residue. The VE-Suite model integration framework has been used to couple a set of environmental process models to support agricultural residue removal decisions. The RUSLE2, WEPS, and Soil Conditioning Index models have been integrated. A disparate set of databases providing the soils, climate, and management practice data required to run these models have also been integrated. The integrated system has been demonstrated for two example cases. First, an assessment using high spatial fidelity crop yield data has been run for a single farm. This analysis shows the significant variance in sustainably accessible residue across a single farm and crop year. A second example is an aggregate assessment of agricultural residues available in the state of Iowa. This implementation of the integrated systems model demonstrates the capability to run a vast range of scenarios required to represent a large geographic region.

  13. Role of Hot Water System Design on Factors Influential to Pathogen Regrowth: Temperature, Chlorine Residual, Hydrogen Evolution, and Sediment.

    Science.gov (United States)

    Brazeau, Randi H; Edwards, Marc A

    2013-10-01

    Residential water heating is linked to growth of pathogens in premise plumbing, which is the primary source of waterborne disease in the United States. Temperature and disinfectant residual are critical factors controlling increased concentration of pathogens, but understanding of how each factor varies in different water heater configurations is lacking. A direct comparative study of electric water heater systems was conducted to evaluate temporal variations in temperature and water quality parameters including dissolved oxygen levels, hydrogen evolution, total and soluble metal concentrations, and disinfectant decay. Recirculation tanks had much greater volumes of water at temperature ranges with potential for increased pathogen growth when set at 49°C compared with standard tank systems without recirculation. In contrast, when set at the higher end of acceptable ranges (i.e., 60°C), this relationship was reversed and recirculation systems had less volume of water at risk for pathogen growth compared with conventional systems. Recirculation tanks also tended to have much lower levels of disinfectant residual (standard systems had 40-600% higher residual), 4-6 times as much hydrogen, and 3-20 times more sediment compared with standard tanks without recirculation. On demand tankless systems had very small volumes of water at risk and relatively high levels of disinfectant residual. Recirculation systems may have distinct advantages in controlling pathogens via thermal disinfection if set at 60°C, but these systems have lower levels of disinfectant residual and greater volumes at risk if set at lower temperatures.

  14. Application of DIALIFE system for residual life time assessment on nuclear power plants

    International Nuclear Information System (INIS)

    Vincour, D.

    2003-01-01

    Instrumentation and Control Systems (I and C), Monitoring and Diagnostic Systems (MDS), Special Temporary Measurement (STM) and Chemical and Laboratory Parameters System enable to obtain detailed information about actual service conditions of power plant components. Thermocouples and strain gauges are used for local measuring near the critical spots of components. The saved data from these systems serve as input data to methods for evaluation in DIALIFE system. A systematic evaluation of experience, safety influence, and design were used for the selection of the critical spots subjected to a degradation. Critical spots are mostly damaged places and consequently determine residual lifetime of whole structure. If critical spots of structure are known, then they have to be included in monitoring the whole structure lifetime. The rapid stress determination on the base of continually measured values by Diagnostic and Monitoring systems is shown. The artificial neural network, prepared stress databases and analytical equation can be used for stress determination for the next assessment using mechanisms of degradation. The experiences from creating database of DIALIFE, selection, acquiring and processing of measured data from various systems of NPP are discussed. Few examples of assessment, opinions and experiences of DIALIFE users are presented. Results from assessment on the base of design transients and measured conditions are shown

  15. Sleep and circadian rhythms in space.

    Science.gov (United States)

    Stampi, C

    1994-05-01

    This paper presents a detailed critical review of the knowledge accumulated in the last three decades concerning research on sleep, work-rest schedules, and circadian rhythms in space. The focus of the paper is preceded by a brief review of the basic principles of the human circadian system and the physiology of the sleep-wake cycle, relevant to understanding the problem of astronaut work-rest scheduling. Much of what is known is based on anecdotal reports, mission log books, and debriefing of astronauts after flights. The broad literature reviewed, which includes studies from American and Soviet space missions, as well as some studies conducted under simulated weightlessness, offers just a handful of objective studies on the physiology of sleep and circadian rhythms in space. Nevertheless, the data are remarkably consistent, and indicate that sleep can be of reasonably good quality in space. The risk of sleep loss and associated performance degradation appears to be a manageable one. However, one clear conclusion arises from this review: whatever the type of mission of flight plan, its success will depend on whether the principles of circadian and sleep-wake regulation have been taken into account during the planning phase of work-rest schedules. That is, satisfactory sleep and alertness is more likely to occur if crews maintain a reasonable (i.e., constant) relation with their normal terrestrial rhythm. This is not as easy a task as it may appear; indeed, unexpected, high-intensity operational demands have been the major cause of acute problems of sleep loss and performance degradation in space. Moreover, the growing complexity of space missions indicate that emergencies will never disappear. Therefore, one of the most important research challenges for future space missions is the development of strategies that could permit astronauts to function closest to maximal efficiency during intensive and prolonged work. Countermeasures for optimizing astronaut

  16. A Hypergraph and Arithmetic Residue-based Probabilistic Neural Network for classification in Intrusion Detection Systems.

    Science.gov (United States)

    Raman, M R Gauthama; Somu, Nivethitha; Kirthivasan, Kannan; Sriram, V S Shankar

    2017-08-01

    Over the past few decades, the design of an intelligent Intrusion Detection System (IDS) remains an open challenge to the research community. Continuous efforts by the researchers have resulted in the development of several learning models based on Artificial Neural Network (ANN) to improve the performance of the IDSs. However, there exists a tradeoff with respect to the stability of ANN architecture and the detection rate for less frequent attacks. This paper presents a novel approach based on Helly property of Hypergraph and Arithmetic Residue-based Probabilistic Neural Network (HG AR-PNN) to address the classification problem in IDS. The Helly property of Hypergraph was exploited for the identification of the optimal feature subset and the arithmetic residue of the optimal feature subset was used to train the PNN. The performance of HG AR-PNN was evaluated using KDD CUP 1999 intrusion dataset. Experimental results prove the dominance of HG AR-PNN classifier over the existing classifiers with respect to the stability and improved detection rate for less frequent attacks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Modelling and analysis of the feeding regimen induced entrainment of hepatocyte circadian oscillators using petri nets.

    Directory of Open Access Journals (Sweden)

    Samar Hayat Khan Tareen

    Full Text Available Circadian rhythms are certain periodic behaviours exhibited by living organism at different levels, including cellular and system-wide scales. Recent studies have found that the circadian rhythms of several peripheral organs in mammals, such as the liver, are able to entrain their clocks to received signals independent of other system level clocks, in particular when responding to signals generated during feeding. These studies have found SIRT1, PARP1, and HSF1 proteins to be the major influencers of the core CLOCKBMAL1:PER-CRY circadian clock. These entities, along with abstracted feeding induced signals were modelled collectively in this study using Petri Nets. The properties of the model show that the circadian system itself is strongly robust, and is able to continually evolve. The modelled feeding regimens suggest that the usual 3 meals/day and 2 meals/day feeding regimens are beneficial with any more or less meals/day negatively affecting the system.

  18. Modelling and Analysis of the Feeding Regimen Induced Entrainment of Hepatocyte Circadian Oscillators Using Petri Nets

    Science.gov (United States)

    Tareen, Samar Hayat Khan; Ahmad, Jamil

    2015-01-01

    Circadian rhythms are certain periodic behaviours exhibited by living organism at different levels, including cellular and system-wide scales. Recent studies have found that the circadian rhythms of several peripheral organs in mammals, such as the liver, are able to entrain their clocks to received signals independent of other system level clocks, in particular when responding to signals generated during feeding. These studies have found SIRT1, PARP1, and HSF1 proteins to be the major influencers of the core CLOCKBMAL1:PER-CRY circadian clock. These entities, along with abstracted feeding induced signals were modelled collectively in this study using Petri Nets. The properties of the model show that the circadian system itself is strongly robust, and is able to continually evolve. The modelled feeding regimens suggest that the usual 3 meals/day and 2 meals/day feeding regimens are beneficial with any more or less meals/day negatively affecting the system. PMID:25789928

  19. Relationship between circadian rhythm amplitude and stability with sleep quality and sleepiness among shift nurses and health care workers.

    Science.gov (United States)

    Jafari Roodbandi, Akram; Choobineh, Alireza; Daneshvar, Somayeh

    2015-01-01

    Sleep is affected by the circadian cycle and its features. Amplitude and stability of circadian rhythm are important parameters of the circadian cycle. This study aims to examine the relationship between amplitude and stability of circadian rhythm with sleep quality and sleepiness. In this cross-sectional research, 315 shift nurses and health care workers from educational hospitals of Kerman University of Medical Sciences (KUMS), Iran, were selected using a random sampling method. The Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Circadian Type Inventory (CTI) were used to collect the required data. In this study, 83.2% suffered from poor sleep and one-half had moderate and excessive sleepiness. The results showed that flexibility in circadian rhythm stability, job stress and sleepiness are among the factors affecting quality sleep in shift workers. Those whose circadian rhythm amplitude was languid suffered more from sleepiness and those whose circadian stability was flexible had a better sleep. Variables including circadian rhythm stability (flexible/rigid) and amplitude (languid/vigorous) can act as predictive indices in order to employ people in a shift work system so that sleepiness and a drop in quality of sleep are prevented.

  20. Compared cycling in a soil-plant system of pea and barley residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1996-01-01

    the 1-3 year period, residual organic labelled N from different residues declined at similar rates, mean decay constant: 0.18 yr(-1). After 3 years, 45% of the barley and on average 32% of the pea residue N were present as soil organic N. The proportion of residue N remaining in the soil after 3 years...... of decomposition was most strongly correlated with the total and soluble N concentrations in the residue. The ratio (% inorganic N derived from residues):(% organic N derived from residues) was used as a measure of the rate residue N stabilization. From initial values of 3-7 the ratios declined to on average 1...... and 35% of the pea residue N were unaccounted for. Since these apparent losses are comparable to almost twice the amounts of pea and barley residue N taken up by the perennial ryegrass crop, there seems to be a potential for improved crop residue management in order to conserve nutrients in the soil...

  1. Redox regulation of circadian molecular clock in chronic airway diseases.

    Science.gov (United States)

    Sundar, Isaac K; Sellix, Michael T; Rahman, Irfan

    2017-10-31

    At the cellular level, circadian timing is maintained by the molecular clock, a family of interacting clock gene transcription factors, nuclear receptors and kinases called clock genes. Daily rhythms in pulmonary function are dictated by the circadian timing system, including rhythmic susceptibility to the harmful effects of airborne pollutants, exacerbations in patients with chronic airway disease and the immune-inflammatory response to infection. Further, evidence strongly suggests that the circadian molecular clock has a robust reciprocal interaction with redox signaling and plays a considerable role in the response to oxidative/carbonyl stress. Disruption of the circadian timing system, particularly in airway cells, impairs pulmonary rhythms and lung function, enhances oxidative stress due to airway inhaled pollutants like cigarette smoke and airborne particulate matter and leads to enhanced inflammosenescence, inflammasome activation, DNA damage and fibrosis. Herein, we briefly review recent evidence supporting the role of the lung molecular clock and redox signaling in regulating inflammation, oxidative stress, and DNA damage responses in lung diseases and their exacerbations. We further describe the potential for clock genes as novel biomarkers and therapeutic targets for the treatment of chronic lung diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  3. Development project for a residual life evaluation system in LWR NPPs

    International Nuclear Information System (INIS)

    Hervia, F.; Francia, L.

    1995-01-01

    Economic and safety factors have stimulated the interest of Spanish NPPs towards the optimisation of NPP Residual Life Management, and consequently the need to have access to tools to support such management. This requirement has been the subject of a project, the main objectives of which are the identification of the most significant ageing factors in NPPs and their corresponding parameters, and the development of an associated integrated monitoring system. Work on the project was started by UNESA in September 1992 and is partly financed from PIE funds. This paper gives a general description of the objectives and activities of Phase 1, the Definition of the Core Project, which is nearing completion, and Phase 2, the Application of the Integrated System in a Pilot Plant. Phase 1 has confirmed the technical feasibility of the system and its suitability as a tool for the continuous evaluation of the plant condition. Furthermore, it has raised issues of great interest to NPPs. The results and conclusions of Phase 1 are currently being used to define the most suitable scope for the development and implementation of the system in the pilot plant (Phase 2), so that all the main functions of the system are tested without incurring unnecessary costs

  4. Cyclic and circadian variations in cardiovascular events.

    Science.gov (United States)

    Elliot, W J

    2001-09-01

    The incidence of many biologic phenomena displays a reproducible and cyclic variation. Cardiovascular disease, the most common cause of death in the United States and other developed countries, also has an intrinsic variation in events. These events are more common in winter, at the beginning of each month, on Mondays (in working people), and during the early morning hours of each day. Recent meta-analyses have quantitated the excess risk of cardiovascular events in the hours around and just after awakening. Between 6 AM and noon, there is a 40% higher risk of heart attack, a 29% increased risk of cardiac death, and a 49% increased risk of stroke (compared with what would be expected if these events happened at random and were evenly distributed throughout the day). These observations have major consequences for emergency medical personnel and medical transport systems. The reasons for these observations are less clear. The circadian pattern of blood pressure (BP) and heart rate may be a major contributor, and long-term "hard end-point" studies designed to test specific pharmacologic interventions targeting the early morning rise in BP and heart rate are underway. Individuals who work night shifts and those whose BP has a different circadian pattern have a higher risk of cardiovascular events, but may be less likely to have an increased risk of cardiovascular events in the morning.

  5. Peroxiredoxins are conserved markers of circadian rhythms

    Science.gov (United States)

    Edgar, Rachel S.; Green, Edward W.; Zhao, Yuwei; van Ooijen, Gerben; Olmedo, Maria; Qin, Ximing; Xu, Yao; Pan, Min; Valekunja, Utham K.; Feeney, Kevin A.; Maywood, Elizabeth S.; Hastings, Michael H.; Baliga, Nitin S.; Merrow, Martha; Millar, Andrew J.; Johnson, Carl H.; Kyriacou, Charalambos P.; O’Neill, John S.; Reddy, Akhilesh B.

    2012-01-01

    Summary Cellular life emerged ~3.7 billion years ago. With scant exception, terrestrial organisms have evolved under predictable daily cycles due to the Earth’s rotation. The advantage conferred upon organisms that anticipate such environmental cycles has driven the evolution of endogenous circadian rhythms that tune internal physiology to external conditions. The molecular phylogeny of mechanisms driving these rhythms has been difficult to dissect because identified clock genes and proteins are not conserved across the domains of life: Bacteria, Archaea and Eukaryota. Here we show that oxidation-reduction cycles of peroxiredoxin proteins constitute a universal marker for circadian rhythms in all domains of life, by characterising their oscillations in a variety of model organisms. Furthermore, we explore the interconnectivity between these metabolic cycles and transcription-translation feedback loops of the clockwork in each system. Our results suggest an intimate co-evolution of cellular time-keeping with redox homeostatic mechanisms following the Great Oxidation Event ~2.5 billion years ago. PMID:22622569

  6. Anaerobic degradation of inedible crop residues produced in a Controlled Ecological Life Support System

    Science.gov (United States)

    Schwingel, W. R.; Sager, J. C.

    1996-01-01

    An anaerobic reactor seeded with organisms from an anaerobic lagoon was used to study the degradation of inedible crop residues from potato and wheat crops grown in a closed environment. Conversion of this biomass into other products was also evaluated. Degradation of wheat volatile solids was about 25% where that of potato was about 50%. The main product of the anaerobic fermentation of both crops was acetic acid with smaller quantities of propionate and butyrate produced. Nitrate, known to be high in concentration in inedible potato and wheat biomass grown hydroponically, was converted to ammonia in the anaerobic reactor. Both volatile fatty acid and ammonia production may have implications in a crop production system.

  7. Minimal tool set for a prokaryotic circadian clock.

    Science.gov (United States)

    Schmelling, Nicolas M; Lehmann, Robert; Chaudhury, Paushali; Beck, Christian; Albers, Sonja-Verena; Axmann, Ilka M; Wiegard, Anika

    2017-07-21

    Circadian clocks are found in organisms of almost all domains including photosynthetic Cyanobacteria, whereby large diversity exists within the protein components involved. In the model cyanobacterium Synechococcus elongatus PCC 7942 circadian rhythms are driven by a unique KaiABC protein clock, which is embedded in a network of input and output factors. Homologous proteins to the KaiABC clock have been observed in Bacteria and Archaea, where evidence for circadian behavior in these domains is accumulating. However, interaction and function of non-cyanobacterial Kai-proteins as well as homologous input and output components remain mainly unclear. Using a universal BLAST analyses, we identified putative KaiC-based timing systems in organisms outside as well as variations within Cyanobacteria. A systematic analyses of publicly available microarray data elucidated interesting variations in circadian gene expression between different cyanobacterial strains, which might be correlated to the diversity of genome encoded clock components. Based on statistical analyses of co-occurrences of the clock components homologous to Synechococcus elongatus PCC 7942, we propose putative networks of reduced and fully functional clock systems. Further, we studied KaiC sequence conservation to determine functionally important regions of diverged KaiC homologs. Biochemical characterization of exemplary cyanobacterial KaiC proteins as well as homologs from two thermophilic Archaea demonstrated that kinase activity is always present. However, a KaiA-mediated phosphorylation is only detectable in KaiC1 orthologs. Our analysis of 11,264 genomes clearly demonstrates that components of the Synechococcus elongatus PCC 7942 circadian clock are present in Bacteria and Archaea. However, all components are less abundant in other organisms than Cyanobacteria and KaiA, Pex, LdpA, and CdpA are only present in the latter. Thus, only reduced KaiBC-based or even simpler, solely KaiC-based timing systems

  8. Short nights attenuate light-induced circadian phase advances in humans.

    Science.gov (United States)

    Burgess, Helen J; Eastman, Charmane I

    2005-08-01

    In humans, sleep duration often determines the night (dark) length experienced, because we close our eyes when we sleep and are exposed to artificial or natural light when we are awake. Although it is recognized that there is an increasing trend in modern society toward shorter sleep time, it is not known how short nights (long photoperiods) affect the human circadian system. In this study we investigated for the first time the effects of night length on circadian phase shifts to light in humans. Eight young healthy subjects experienced 2 wk of 6-h sleep episodes in the dark (short nights) and 2 wk of long 9-h sleep episodes (long nights) in counterbalanced order. After each series of nights, they were exposed to four 30-min pulses of morning bright light (approximately 5000 lux) that advanced by 1 h/d for 3 consecutive days while night (dark) length was maintained at 6 or 9 h. Circadian phase was determined from the circadian rhythm of melatonin in dim light before and after the 3-d bright light treatments. The phase advance in the melatonin rhythm during the short nights was less than half of that observed during the long nights (P time that people who curtail their sleep may unwittingly reduce their circadian responsiveness to morning light. This finding also demonstrates that sleep length can alter human circadian function and has important implications for enhancing the treatment of circadian rhythm sleep disorders.

  9. Daily Light Exposure Patterns Reveal Phase and Period of the Human Circadian Clock.

    Science.gov (United States)

    Woelders, Tom; Beersma, Domien G M; Gordijn, Marijke C M; Hut, Roelof A; Wams, Emma J

    2017-06-01

    Light is the most potent time cue that synchronizes (entrains) the circadian pacemaker to the 24-h solar cycle. This entrainment process is an interplay between an individual's daily light perception and intrinsic pacemaker period under free-running conditions. Establishing individual estimates of circadian phase and period can be time-consuming. We show that circadian phase can be accurately predicted (SD = 1.1 h for dim light melatonin onset, DLMO) using 9 days of ambulatory light and activity data as an input to Kronauer's limit-cycle model for the human circadian system. This approach also yields an estimated circadian period of 24.2 h (SD = 0.2 h), with longer periods resulting in later DLMOs. A larger amount of daylight exposure resulted in an earlier DLMO. Individuals with a long circadian period also showed shorter intervals between DLMO and sleep timing. When a field-based estimation of tau can be validated under laboratory studies in a wide variety of individuals, the proposed methods may prove to be essential tools for individualized chronotherapy and light treatment for shift work and jetlag applications. These methods may improve our understanding of fundamental properties of human circadian rhythms under daily living conditions.

  10. Calcium and Magnesium Released from Residues in an Integrated Crop-Livestock System under Different Grazing Intensities

    Directory of Open Access Journals (Sweden)

    Joice Mari Assmann

    Full Text Available ABSTRACT Under integrated crop-livestock production systems (ICLS, plant and animal residues are important nutrient stocks for plant growth. Grazing management, by affecting the numbers of both plants and animals and the quality of residues, will influence nutrient release rates. The objective of this study was to evaluate the impact of grazing intensity on Ca and Mg release from pasture, dung, and soybean residues in a long-term no-till integrated soybean-cattle system. The experiment was established in May 2001 in a Latossolo Vermelho Distroférrico (Rhodic Hapludox. Treatments were a gradient of grazing intensity, determined by managing a black oat + Italian ryegrass pasture at 10, 20, 30, and 40 cm grazing height and no-grazing (NG, followed by soybean cropping. Ca and Mg release rates were determined in two entire cycles (2009/11. Moderate grazing (20 and 30 cm sward height led to greater Ca and Mg release rates from pasture and dung residues, with low average half-life values (13 and 3 days for Ca and 16 and 6 days for Mg for pasture and dung, respectively. Grazing compared with NG resulted in greater Ca and Mg release from pasture and dung residues. Grazing intensity did not affect Ca and Mg release rates or amounts from soybean residues, but Ca and Mg release rates were greater from soybean leaves than from stems. Although moderate grazing intensities produce higher quality residues and higher calcium and magnesium release rates, a higher total nutrient amount is released by light grazing intensity and no-grazing, determined by higher residue production. Grazing intensity is, then, important for nutrient dynamics in the soil-plant-animal continuum.

  11. High-throughput mosquito and fly bioassay system for natural and artificial substrates treated with residual insecticides.

    Science.gov (United States)

    Aldridge, Robert L; Wynn, W Wayne; Britch, Seth C; Allan, Sandra A; Walker, Todd W; Geden, Christopher J; Hogsette, Jerome A; Linthicum, Kenneth J

    2013-03-01

    A high-throughput bioassay system to evaluate the efficacy of residual pesticides against mosquitoes and muscid flies with minimal insect handling was developed. The system consisted of 4 components made of readily available materials: 1) a CO2 anaesthetizing chamber, 2) a specialized aspirator, 3) a cylindrical flat-bottomed glass bioassay chamber assembly, and 4) a customized rack.

  12. Passive residual energy utilization system in thermal cycles on water-cooled power reactors

    International Nuclear Information System (INIS)

    Placco, Guilherme M.; Guimaraes, Lamartine N.F.; Santos, Rubens S. dos

    2013-01-01

    This work presents a concept of a residual energy utilization in nuclear plants thermal cycles. After taking notice of the causes of the Fukushima nuclear plant accident, an idea arose to adapt a passive thermal circuit as part of the ECCS (Emergency Core Cooling System). One of the research topics of IEAv (Institute for Advanced Studies), as part of the heat conversion of a space nuclear power system is a passive multi fluid turbine. One of the main characteristics of this device is its passive capability of staying inert and be brought to power at moments notice. During the first experiments and testing of this passive device, it became clear that any small amount of gas flow would generate power. Given that in the first stages of the Fukushima accident and even during the whole event there was plenty availability of steam flow that would be the proper condition to make the proposed system to work. This system starts in case of failure of the ECCS, including loss of site power, loss of diesel generators and loss of the battery power. This system does not requires electricity to run and will work with bleed steam. It will generate enough power to supply the plant safety system avoiding overheating of the reactor core produced by the decay heat. This passive system uses a modified Tesla type turbine. With the tests conducted until now, it is possible to ensure that the operation of this new turbine in a thermal cycle is very satisfactory and it performs as expected. (author)

  13. Passive residual energy utilization system in thermal cycles on water-cooled power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Placco, Guilherme M.; Guimaraes, Lamartine N.F., E-mail: placco@ieav.cta.br, E-mail: guimarae@ieav.cta.br [Instituto de Estudos Avancados (IEAV/DCTA) Sao Jose dos Campos, SP (Brazil); Santos, Rubens S. dos, E-mail: rsantos@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN -RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This work presents a concept of a residual energy utilization in nuclear plants thermal cycles. After taking notice of the causes of the Fukushima nuclear plant accident, an idea arose to adapt a passive thermal circuit as part of the ECCS (Emergency Core Cooling System). One of the research topics of IEAv (Institute for Advanced Studies), as part of the heat conversion of a space nuclear power system is a passive multi fluid turbine. One of the main characteristics of this device is its passive capability of staying inert and be brought to power at moments notice. During the first experiments and testing of this passive device, it became clear that any small amount of gas flow would generate power. Given that in the first stages of the Fukushima accident and even during the whole event there was plenty availability of steam flow that would be the proper condition to make the proposed system to work. This system starts in case of failure of the ECCS, including loss of site power, loss of diesel generators and loss of the battery power. This system does not requires electricity to run and will work with bleed steam. It will generate enough power to supply the plant safety system avoiding overheating of the reactor core produced by the decay heat. This passive system uses a modified Tesla type turbine. With the tests conducted until now, it is possible to ensure that the operation of this new turbine in a thermal cycle is very satisfactory and it performs as expected. (author)

  14. Circadian remodeling of neuronal circuits involved in rhythmic behavior.

    Directory of Open Access Journals (Sweden)

    María Paz Fernández

    2008-03-01

    Full Text Available Clock output pathways are central to convey timing information from the circadian clock to a diversity of physiological systems, ranging from cell-autonomous processes to behavior. While the molecular mechanisms that generate and sustain rhythmicity at the cellular level are well understood, it is unclear how this information is further structured to control specific behavioral outputs. Rhythmic release of pigment dispersing factor (PDF has been proposed to propagate the time of day information from core pacemaker cells to downstream targets underlying rhythmic locomotor activity. Indeed, such circadian changes in PDF intensity represent the only known mechanism through which the PDF circuit could communicate with its output. Here we describe a novel circadian phenomenon involving extensive remodeling in the axonal terminals of the PDF circuit, which display higher complexity during the day and significantly lower complexity at nighttime, both under daily cycles and constant conditions. In support to its circadian nature, cycling is lost in bona fide clockless mutants. We propose this clock-controlled structural plasticity as a candidate mechanism contributing to the transmission of the information downstream of pacemaker cells.

  15. Are circadian rhythms new pathways to understand Autism Spectrum Disorder?

    Science.gov (United States)

    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.

  16. Assessing microbiological water quality in drinking water distribution systems with disinfectant residual using flow cytometry.

    Science.gov (United States)

    Gillespie, Simon; Lipphaus, Patrick; Green, James; Parsons, Simon; Weir, Paul; Juskowiak, Kes; Jefferson, Bruce; Jarvis, Peter; Nocker, Andreas

    2014-11-15

    Flow cytometry (FCM) as a diagnostic tool for enumeration and characterization of microorganisms is rapidly gaining popularity and is increasingly applied in the water industry. In this study we applied the method to obtain a better understanding of total and intact cell concentrations in three different drinking water distribution systems (one using chlorine and two using chloramines as secondary disinfectants). Chloramine tended to result in lower proportions of intact cells than chlorine over a wider residual range, in agreement with existing knowledge that chloramine suppresses regrowth more efficiently. For chlorinated systems, free chlorine concentrations above 0.5 mg L(-1) were found to be associated with relatively low proportions of intact cells, whereas lower disinfectant levels could result in substantially higher percentages of intact cells. The threshold for chlorinated systems is in good agreement with guidelines from the World Health Organization. The fact that the vast majority of samples failing the regulatory coliform standard also showed elevated proportions of intact cells suggests that this parameter might be useful for evaluating risk of failure. Another interesting parameter for judging the microbiological status of water, the biological regrowth potential, greatly varied among different finished waters providing potential help for investment decisions. For its measurement, a simple method was introduced that can easily be performed by water utilities with FCM capability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Bioenergy for District Bioheating System (DBS) from eucalyptus residues in a European coal-producing region

    International Nuclear Information System (INIS)

    Paredes-Sánchez, José P.; López-Ochoa, Luis M.; López-González, Luis M.; Xiberta-Bernat, Jorge

    2016-01-01

    Highlights: • The paper introduces a combined method to evaluate bioenergy. • Forest biomass needs to be studied as a fuel supplier and carbon sink. • The forests under study produce about 28 kt dry and 0.15 Mt CO 2 per year. • Examined a District Bioheating System (DBS) with the available biomass. - Abstract: Since forest biomass can substitute for CO 2 -emitting fossil fuels in the energy sector, forest management can greatly affect the global carbon cycle. Eucalyptus globulus has adapted very well in the coal region of the Principality of Asturias (Northwestern Spain) and has become highly regarded as a valuable raw material for the pulp and paper industry. In the present work, the Eucalyptus globulus is studied as a key natural energy source in order to improve existing methods and develop new ways of optimizing the evaluation and use of both forest biomass and woody residue in energy systems, in accordance with sustainable forestry industry safety and environmental requirements. The feasibility of utilizing forest biomass instead of natural gas in a District Bioheating System (DBS) has been examined based on an analysis of its economical and environmental impacts.

  18. Cellular bases of radiation-induced residual insufficiency in the haematopoietic system

    International Nuclear Information System (INIS)

    Wangenheim, K.H. v.; Peterson, H.P.; Feinendegen, L.E.

    1984-01-01

    Following radiation exposure, man's survival and further well-being largely depends on the degree of damage to his heamatopietic system. Stem cells are particualarly sensitive to radiation. Over and beyond acute radiation damge, residual radiation damage is of significance since it reduces the performance of the haematopietic system and enhances the risk of leukaemia. Knowledge concerning cellular bases may be important for preventive and therapeutic measures. The measurement method presented is based on the fact that stem cells from transfused bone marrow will settle in the spleen of highly irradiated mice and be able to reconstruct the haematopietic system. Initally individual colonies can be observed which originate from a single stem cell and the proliferation of its descendants. Counting these colonies will give the number of stem cells. The reduction of the proliferation factor measured in the stem-cell quality test apparently is not due to a shift in the age structure of the stem cell compartment but to a damage which is located within a more or less substantial proportion of the stem cells themselves. This damage is the cause of stem cell descendant growth retarded on an average. It is probable that recovery observed after irradiation is brought about by less-damaged or undamaged stem cells replacing damaged ones. Initial results point to the fact that this replacement can be influenced by treatment after irradiation. (orig./MG) [de

  19. The Circadian Clock Gene BMAL1 Coordinates Intestinal RegenerationSummary

    Directory of Open Access Journals (Sweden)

    Kyle Stokes

    2017-07-01

    Full Text Available Background & Aims: The gastrointestinal syndrome is an illness of the intestine caused by high levels of radiation. It is characterized by extensive loss of epithelial tissue integrity, which initiates a regenerative response by intestinal stem and precursor cells. The intestine has 24-hour rhythms in many physiological functions that are believed to be outputs of the circadian clock: a molecular system that produces 24-hour rhythms in transcription/translation. Certain gastrointestinal illnesses are worsened when the circadian rhythms are disrupted, but the role of the circadian clock in gastrointestinal regeneration has not been studied. Methods: We tested the timing of regeneration in the mouse intestine during the gastrointestinal syndrome. The role of the circadian clock was tested genetically using the BMAL1 loss of function mouse mutant in vivo, and in vitro using intestinal organoid culture. Results: The proliferation of the intestinal epithelium follows a 24-hour rhythm during the gastrointestinal syndrome. The circadian clock runs in the intestinal epithelium during this pathologic state, and the loss of the core clock gene, BMAL1, disrupts both the circadian clock and rhythmic proliferation. Circadian activity in the intestine involves a rhythmic production of inflammatory cytokines and subsequent rhythmic activation of the JNK stress response pathway. Conclusions: Our results show that a circadian rhythm in inflammation and regeneration occurs during the gastrointestinal syndrome. The study and treatment of radiation-induced illnesses, and other gastrointestinal illnesses, should consider 24-hour timing in physiology and pathology. Keywords: Intestine, Circadian Rhythms, Gastrointestinal Syndrome, TNF, Intestinal Stem Cells

  20. Individual differences in circadian locomotor parameters correlate with anxiety- and depression-like behavior.

    Directory of Open Access Journals (Sweden)

    Jeffrey Anyan

    Full Text Available Disrupted circadian rhythms are a core feature of mood and anxiety disorders. Circadian rhythms are coordinated by a light-entrainable master clock located in the suprachiasmatic nucleus. Animal models of mood and anxiety disorders often exhibit blunted rhythms in locomotor activity and clock gene expression. Interestingly, the changes in circadian rhythms correlate with mood-related behaviours. Although animal models of depression and anxiety exhibit aberrant circadian rhythms in physiology and behavior, it is possible that the methodology being used to induce the behavioral phenotype (e.g., brain lesions, chronic stress, global gene deletion affect behavior independently of circadian system. This study investigates the relationship between individual differences in circadian locomotor parameters and mood-related behaviors in healthy rats. The circadian phenotype of male Lewis rats was characterized by analyzing wheel running behavior under standard 12h:12h LD conditions, constant dark, constant light, and rate of re-entrainment to a phase advance. Rats were then tested on a battery of behavioral tests: activity box, restricted feeding, elevated plus maze, forced swim test, and fear conditioning. Under 12h:12h LD conditions, percent of daily activity in the light phase and variability in activity onset were associated with longer latency to immobility in the forced swim test. Variability in onset also correlated positively with anxiety-like behavior in the elevated plus maze. Rate of re-entrainment correlated positively with measures of anxiety in the activity box and elevated plus maze. Lastly, we found that free running period under constant dark was associated with anxiety-like behaviors in the activity box and elevated plus maze. Our results provide a previously uncharacterized relationship between circadian locomotor parameters and mood-related behaviors in healthy rats and provide a basis for future examination into circadian clock

  1. The relationship between circadian disruption and the development of metabolic syndrome and type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Karatsoreos IN

    2014-12-01

    Full Text Available Ilia N Karatsoreos Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA Abstract: Circadian (daily rhythms are pervasive in nature, and expressed in nearly every behavioral and physiological process. In mammals, circadian rhythms are regulated by the master brain clock in the suprachiasmatic nucleus of the hypothalamus that coordinates the activity of “peripheral” oscillators throughout the brain and body. While much progress has been made in understanding the basic functioning of the circadian clock at the level of genes, molecules, and cells, our understanding of how these clocks interact with complex systems is still in its infancy. Much recent work has focused on the role of circadian clocks in the etiology of disorders as diverse as cancer, diabetes, and obesity. Given the rapid rise in obesity, and the economic costs involved in treating its associated cardiometabolic disorders such as heart disease and diabetes mellitus, understanding the development of obesity and metabolic dysregulation is crucial. Significant epidemiological data indicate a role for circadian rhythms in metabolic disorders. Shift workers have a higher incidence of obesity and diabetes, and laboratory studies in humans show misaligning sleep and the circadian clock leads to hyperinsulinemia. In animal models, body-wide “clock gene” knockout mice are prone to obesity. Further, disrupting the circadian clock by manipulating the light–dark cycle can result in metabolic dysregulation and development of obesity. At the molecular level, elegant studies have shown that targeted disruption of the genetic circadian clock in the pancreas leads to diabetes, highlighting the fact that the circadian clock is directly coupled to metabolism at the cellular level. Keywords: glucose, metabolism, sleep, rhythms, obesity

  2. Deposition behavior of residual aluminum in drinking water distribution system: Effect of aluminum speciation.

    Science.gov (United States)

    Zhang, Yue; Shi, Baoyou; Zhao, Yuanyuan; Yan, Mingquan; Lytle, Darren A; Wang, Dongsheng

    2016-04-01

    Finished drinking water usually contains some residual aluminum. The deposition of residual aluminum in distribution systems and potential release back to the drinking water could significantly influence the water quality at consumer taps. A preliminary analysis of aluminum content in cast iron pipe corrosion scales and loose deposits demonstrated that aluminum deposition on distribution pipe surfaces could be excessive for water treated by aluminum coagulants including polyaluminum chloride (PACl). In this work, the deposition features of different aluminum species in PACl were investigated by simulated coil-pipe test, batch reactor test and quartz crystal microbalance with dissipation monitoring. The deposition amount of non-polymeric aluminum species was the least, and its deposition layer was soft and hydrated, which indicated the possible formation of amorphous Al(OH)3. Al13 had the highest deposition tendency, and the deposition layer was rigid and much less hydrated, which indicated that the deposited aluminum might possess regular structure and self-aggregation of Al13 could be the main deposition mechanism. While for Al30, its deposition was relatively slower and deposited aluminum amount was relatively less compared with Al13. However, the total deposited mass of Al30 was much higher than that of Al13, which was attributed to the deposition of particulate aluminum matters with much higher hydration state. Compared with stationary condition, stirring could significantly enhance the deposition process, while the effect of pH on deposition was relatively weak in the near neutral range of 6.7 to 8.7. Copyright © 2015. Published by Elsevier B.V.

  3. Concept Design of a Gravity Core Cooling Tank as a Passive Residual Heat Removal System for a Research Reactor

    International Nuclear Information System (INIS)

    Lee, Kwonyeong; Chi, Daeyoung; Kim, Seong Hoon; Seo, Kyoungwoo; Yoon, Juhyeon

    2014-01-01

    A core downward flow is considered to use a plate type fuel because it is benefit to install the fuel in the core. If a flow inversion from a downward to upward flow in the core by a natural circulation is introduced within a high heat flux region of residual heat, the fuel fails instantly due to zero flow. Therefore, the core downward flow should be sufficiently maintained until the residual heat is in a low heat flux region. In a small power research reactor, inertia generated by a flywheel of the PCP can maintain a downward flow shortly and resolve the problem of a flow inversion. However, a high power research reactor more than 10 MW should have an additional method to have a longer downward flow until a low heat flux. Usually, other research reactors have selected an active residual heat removal system as a safety class. But, an active safety system is difficult to design and expensive to construct. A Gravity Core Cooling Tank (GCCT) beside the reactor pool with a Residual Heat Removal Pipe connecting two pools was developed and designed preliminarily as a passive residual heat removal system for an open-pool type research reactor. It is very simple to design and cheap to construct. Additionally, a non-safety, but active residual heat removal system is applied with the GCCT. It is a Pool Water Cooling and Purification System. It can improve the usability of the research reactor by removing the thermal waves, and purify the reactor pool, the Primary Cooling System, and the GCCT. Moreover, it can reduce the pool top radiation level

  4. Non-alcoholic fatty liver disease as a consequence of autonomic imbalance and circadian desynchronization.

    Science.gov (United States)

    Sabath, E; Báez-Ruiz, A; Buijs, R M

    2015-10-01

    The circadian system, headed by the suprachiasmatic nucleus, synchronizes behaviour and metabolism according to the external light-dark cycle through neuroendocrine and autonomic signals. Metabolic diseases, such as steatosis, obesity and glucose intolerance, have been associated with conditions of circadian misalignment wherein the feeding schedule has been moved to the resting phase. Here we describe the physiological processes involved in liver lipid accumulation and show how they follow a circadian pattern importantly regulated by both the autonomic nervous system and the feeding-fasting cycle. We propose that an unbalanced activity of the sympathetic-parasympathetic branches between organs induced by circadian misalignment provides the conditions for the development and progression of non-alcoholic fatty liver disease. © 2015 World Obesity.

  5. A process for treatment of residues from dry/semidry APC systems at municipal solid waste incinerators. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hjelmar, O. [VKI, Hoersholm (Denmark)] Holland, D. [FLS miljoe a/s, Valby (Denmark)] Poulsen, B. [KARA, Roskilde (Denmark)

    1997-08-01

    The main objective of the project has been to establish and test a process for treatment of residues from the semidry (and dry) lime injection based APC processes at MSWIs, which will ensure that the residues can be managed in an environmentally safe manner. In pursuit of this goal, the following activities have been carried out: Performance of pilot scale extractions (approximately 50 kg of residue per batch) at the KARA MSWI in Roskilde of semidry APC system residues in order to establish and optimize process conditions. The optimization includes consideration of the possibilities for subsequent treatment/stabilization of the extracted solid phase as well as the possibility of treatment and safe discharge/utilization of the extract; Performance of chemical characterization, hydrogeochemical model calculations and experimental work in order to improve the understanding of the mechanisms and factors which for several contaminants control the equilibrium between the solid and liquid phases, both in the short and the long germ, and to use this information to obtain an environmentally acceptable method for stabilization/treatment of the extracted residues while at the same time minimizing the necessary amount of additives; production of treated residues and performance of leaching tests on these to assess and demonstrate the effectiveness of the entire process (extraction + stabilization/treatment); Evaluation of the technical, economical and environmental consequences of full scale implementation of the process. (EG) EFP-94. 19 refs.

  6. Residual thermal stress simulation in three-dimensional molar crown systems: a finite element analysis.

    Science.gov (United States)

    Bonfante, Estevam A; Rafferty, Brian T; Silva, Nelson R F A; Hanan, Jay C; Rekow, Elizabeth Dianne; Thompson, Van P; Coelho, Paulo G

    2012-10-01

    To simulate coefficient of thermal expansion (CTE)-generated stress fields in monolithic metal and ceramic crowns, and CTE mismatch stresses between metal, alumina, or zirconia cores and veneer layered crowns when cooled from high temperature processing. A 3D computer-aided design model of a mandibular first molar crown was generated. Tooth preparation comprised reduction of proximal walls by 1.5 mm and of occlusal surfaces by 2.0 mm. Crown systems were monolithic (all-porcelain, alumina, metal, or zirconia) or subdivided into a core (metallic, zirconia, or alumina) and a porcelain veneer layer. The model was thermally loaded from 900°C to 25°C. A finite element mesh of three nodes per edge and a first/last node interval ratio of 1 was used, resulting in approximately 60,000 elements for both solids. Regions and values of maximum principal stress at the core and veneer layers were determined through 3D graphs and software output. The metal-porcelain and zirconia-porcelain systems showed compressive fields within the veneer cusp bulk, whereas alumina-porcelain presented tensile fields. At the core/veneer interface, compressive fields were observed for the metal-porcelain system, slightly tensile for the zirconia-porcelain, and higher tensile stress magnitudes for the alumina-porcelain. Increasingly compressive stresses were observed for the metal, alumina, zirconia, and all-porcelain monolithic systems. Variations in residual thermal stress levels were observed between bilayered and single-material systems due to the interaction between crown configuration and material properties. © 2012 by the American College of Prosthodontists.

  7. Block quasi-minimal residual iterations for non-Hermitian linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Freund, R.W. [AT& T Bell Labs., Murray Hill, NJ (United States)

    1994-12-31

    Many applications require the solution of multiple linear systems that have the same coefficient matrix, but differ only in their right-hand sides. Instead of applying an iterative method to each of these systems individually, it is usually more efficient to employ a block version of the method that generates blocks of iterates for all the systems simultaneously. An example of such an iteration is the block conjugate gradient algorithm, which was first studied by Underwood and O`Leary. On parallel architectures, block versions of conjugate gradient-type methods are attractive even for the solution of single linear systems, since they have fewer synchronization points than the standard versions of these algorithms. In this talk, the author presents a block version of Freund and Nachtigal`s quasi-minimal residual (QMR) method for the iterative solution of non-Hermitian linear systems. He describes two different implementations of the block-QMR method, one based on a block version of the three-term Lanczos algorithm and one based on coupled two-term block recurrences. In both cases, the underlying block-Lanczos process still allows arbitrary normalizations of the vectors within each block, and the author discusses different normalization strategies. To maintain linear independence within each block, it is usually necessary to reduce the block size in the course of the iteration, and the author describes a deflation technique for performing this reduction. He also present some convergence results, and reports results of numerical experiments with the block-QMR method. Finally, the author discusses possible block versions of transpose-free Lanczos-based iterations such as the TFQMR method.

  8. Thoracic surface temperature rhythms as circadian biomarkers for cancer chronotherapy

    Science.gov (United States)

    Roche, Véronique Pasquale; Mohamad-Djafari, Ali; Innominato, Pasquale Fabio; Karaboué, Abdoulaye; Gorbach, Alexander; Lévi, Francis Albert

    2014-01-01

    The disruption of the temperature circadian rhythm has been associated with cancer progression, while its amplification resulted in cancer inhibition in experimental tumor models. The current study investigated the relevance of skin surface temperature rhythms as biomarkers of the Circadian Timing System (CTS) in order to optimize chronotherapy timing in individual cancer patients. Baseline skin surface temperature at four sites and wrist accelerations were measured every minute for 4 days in 16 patients with metastatic gastro-intestinal cancer before chronotherapy administration. Temperature and rest-activity were recorded, respectively, with wireless skin surface temperature patches (Respironics, Phillips) and an actigraph (Ambulatory Monitoring). Both variables were further monitored in 10 of these patients during and after a 4-day course of a fixed chronotherapy protocol. Collected at baseline, during and after therapy longitudinal data sets were processed using Fast Fourier Transform Cosinor and Linear Discriminant Analyses methods. A circadian rhythm was statistically validated with a period of 24 h (p|0.7|; p<0.05). Individual circadian acrophases at baseline were scattered from 15:18 to 6:05 for skin surface temperature, and from 12:19 to 15:18 for rest-activity, with respective median values of 01:10 (25–75% quartiles, 22:35–3:07) and 14:12 (13:14–14:31). The circadian patterns in skin surface temperature and rest-activity persisted or were amplified during and after fixed chronotherapy delivery for 5/10 patients. In contrast, transient or sustained disruption of these biomarkers was found for the five other patients, as indicated by the lack of any statistically significant dominant period in the circadian range. No consistent correlation (r<|0.7|, p ≥ 0.05) was found between paired rest-activity and temperature time series during fixed chronotherapy delivery. In conclusion, large inter-patient differences in circadian amplitudes and acrophases of

  9. Drosophila: An Emergent Model for Delineating Interactions between the Circadian Clock and Drugs of Abuse

    Directory of Open Access Journals (Sweden)

    Aliza K. De Nobrega

    2017-01-01

    Full Text Available Endogenous circadian oscillators orchestrate rhythms at the cellular, physiological, and behavioral levels across species to coordinate activity, for example, sleep/wake cycles, metabolism, and learning and memory, with predictable environmental cycles. The 21st century has seen a dramatic rise in the incidence of circadian and sleep disorders with globalization, technological advances, and the use of personal electronics. The circadian clock modulates alcohol- and drug-induced behaviors with circadian misalignment contributing to increased substance use and abuse. Invertebrate models, such as Drosophila melanogaster, have proven invaluable for the identification of genetic and molecular mechanisms underlying highly conserved processes including the circadian clock, drug tolerance, and reward systems. In this review, we highlight the contributions of Drosophila as a model system for understanding the bidirectional interactions between the circadian system and the drugs of abuse, alcohol and cocaine, and illustrate the highly conserved nature of these interactions between Drosophila and mammalian systems. Research in Drosophila provides mechanistic insights into the corresponding behaviors in higher organisms and can be used as a guide for targeted inquiries in mammals.

  10. Productivity and cost analysis of a mobile pyrolysis system deployed to convert mill residues into biochar

    Science.gov (United States)

    Woodam Chung; Dongyeob Kim; Nathaniel Anderson

    2012-01-01

    Forest and mill residues are a promising source of biomass feedstock for the production of bioenergy, biofuels and bioproducts. However, high costs of transportation and handling of feedstock often make utilization of forest residues, such as logging slash, financially unviable. As a result, these materials are often considered waste and left on site to decompose or...

  11. Calibration of a portable cost-effective chemical residue detection system with adaptive neural net control

    Science.gov (United States)

    Tripp, Alan C.; Walker, James C.

    2003-07-01

    The Sensory Research Institute at the Florida State University has quantitatively characterized a chemical residue detection system with adaptive neural net data processing. Two separate configurations, "Stormy" and "Gaea", were trained by exposure to decreasing amounts of n-amyl acetate from chemical emitters randomly distributed among a collection of non-emitters. The concentration of chemical in the sampled air stream was controlled precisely. The detection threshold for "Stormy" was 1.14 ppt; that for "Gaea" was 1.9 ppt. Cycle time for sampling and chemical analysis of each sample port was on the order of seconds. Possible effects on the sensors of environmental factors such as ambient humidity, temperature, and air velocity were not considered. Besides processing individual air sample data, the neural nets can sense concentration gradients and track to chemical source. The adaptive neural nets are accessed by a voice recognition system and are capable of point testing or free-ranging search. The service life of the detectors, the neural net processors, and auxiliary packaging is approximately 8 years under normal field use. Maintenance requires a good quality kibble and an occasional romp in the park.

  12. Determination of oxytetracycline residues in matrixes from a freshwater recirculating aquaculture system.

    Science.gov (United States)

    Carson, Mary C; Bullock, Graham; Bebak-Williams, Julie

    2002-01-01

    This paper describes related procedures to determine the amount of oxytetracycline (OTC) present in trout tissue (muscle with skin attached), biofilter sand, sediment, and tank water from a recirculating aquaculture system. OTC was extracted from the matrixes by different techniques, depending on complexity of the matrix and desired OTC detection level in that matrix. Listed in order of increasing complexity, OTC was extracted from tank water by dilution with acidic buffer containing ethylenediaminetetraacetic acid (EDTA); from biofilter sand by shaking with 0.1 N HCl; from sediment by homogenization and shaking with buffer/EDTA; and from ground trout by homogenization and shaking with buffer/EDTA (twice), with further cleanup and concentration of the extract on a polymeric solid-phase extraction cartridge. The 4 procedures all used the same reversed-phase gradient chromatography on a polymeric column with UV detection at 350 nm. The lower limit of detection (estimated) and upper limit of validation for each of these 4 matrixes were 0.04-4.0 microg/g (ppm; trout), 0.03-20 ppm (biofilter sand), 1-6000 ppm (sediment), and 0.003-10 ppm (water). Recoveries ranged from 82 to 108%, with relative standard deviation <20% over the applicable concentration ranges. These procedures were used to monitor OTC residues resulting from medicated feed administered to rainbow trout in a recirculating aquaculture system.

  13. Model based fault detection and diagnosis using structured residual approach in a multi-input multi-output system

    Directory of Open Access Journals (Sweden)

    Asokan A.

    2007-01-01

    Full Text Available Fault detection and isolation (FDI is a task to deduce from observed variable of the system if any component is faulty, to locate the faulty components and also to estimate the fault magnitude present in the system. This paper provides a systematic method of fault diagnosis to detect leak in the three-tank process. The proposed scheme makes use of structured residual approach for detection, isolation and estimation of faults acting on the process [1]. This technique includes residual generation and residual evaluation. A literature review showed that the conventional fault diagnosis methods like the ordinary Chisquare (ψ2 test method, generalized likelihood ratio test have limitations such as the "false alarm" problem. From the results it is inferred that the proposed FDI scheme diagnoses better when compared to other conventional methods.

  14. Circadian Rhythms and Substance Abuse: Chronobiological Considerations for the Treatment of Addiction.

    Science.gov (United States)

    Webb, Ian C

    2017-02-01

    Reward-related learning, including that associated with drugs of abuse, is largely mediated by the dopaminergic mesolimbic pathway. Mesolimbic neurophysiology and motivated behavior, in turn, are modulated by the circadian timing system which generates ∼24-h rhythms in cellular activity. Both drug taking and seeking and mesolimbic dopaminergic neurotransmission can vary widely over the day. Moreover, circadian clock genes are expressed in ventral tegmental area dopaminergic cells and in mesolimbic target regions where they can directly modulate reward-related neurophysiology and behavior. There also exists a reciprocal influence between drug taking and circadian timing as the administration of drugs of abuse can alter behavioral rhythms and circadian clock gene expression in mesocorticolimbic structures. These interactions suggest that manipulations of the circadian timing system may have some utility in the treatment of substance abuse disorders. Here, the literature on bidirectional interactions between the circadian timing system and drug taking is briefly reviewed, and potential chronotherapeutic considerations for the treatment of addiction are discussed.

  15. Critical role of the circadian clock in memory formation: lessons from Aplysia.

    Science.gov (United States)

    Lyons, Lisa C

    2011-01-01

    Unraveling the complexities of learning and the formation of memory requires identification of the cellular and molecular processes through which neural plasticity arises as well as recognition of the conditions or factors through which those processes are modulated. With its relatively simple nervous system, the marine mollusk Aplysia californica has proven an outstanding model system for studies of memory formation and identification of the molecular mechanisms underlying learned behaviors, including classical and operant associative learning paradigms and non-associative behaviors. In vivo behavioral studies in Aplysia have significantly furthered our understanding of how the endogenous circadian clock modulates memory formation. Sensitization of the tail-siphon withdrawal reflex represents a defensive non-associative learned behavior for which the circadian clock strongly modulates intermediate and long-term memory formation. Likewise, Aplysia exhibit circadian rhythms in long-term memory, but not short-term memory, for an operant associative learning paradigm. This review focuses on circadian modulation of intermediate and long-term memory and the putative mechanisms through which this modulation occurs. Additionally, potential functions and the adaptive advantages of time of day pressure on memory formation are considered. The influence of the circadian clock on learning and memory crosses distant phylogeny highlighting the evolutionary importance of the circadian clock on metabolic, physiological, and behavioral processes. Thus, studies in a simple invertebrate model system have and will continue to provide critical mechanistic insights to complementary processes in higher organisms.

  16. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2008-12-07

    Dec 7, 2008 ... large variety of tissues in the fly such as the eye, brain, pro- boscis, antennae, wings, abdomen, Malpighian tubules and testes (Plautz et al. 1997; Giebultowicz 2001). Although cell-autonomous circadian function is attributed to several tissues in Drosophila, circadian pacemaker neurons located in the brain ...

  17. Development of cortisol circadian rhythm in infancy.

    NARCIS (Netherlands)

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

    2003-01-01

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

  18. The Impact of Sleep and Circadian Disturbance on Hormones and Metabolism

    Directory of Open Access Journals (Sweden)

    Tae Won Kim

    2015-01-01

    Full Text Available The levels of several hormones fluctuate according to the light and dark cycle and are also affected by sleep, feeding, and general behavior. The regulation and metabolism of several hormones are influenced by interactions between the effects of sleep and the intrinsic circadian system; growth hormone, melatonin, cortisol, leptin, and ghrelin levels are highly correlated with sleep and circadian rhythmicity. There are also endogenous circadian mechanisms that serve to regulate glucose metabolism and similar rhythms pertaining to lipid metabolism, regulated through the actions of various clock genes. Sleep disturbance, which negatively impacts hormonal rhythms and metabolism, is also associated with obesity, insulin insensitivity, diabetes, hormonal imbalance, and appetite dysregulation. Circadian disruption, typically induced by shift work, may negatively impact health due to impaired glucose and lipid homeostasis, reversed melatonin and cortisol rhythms, and loss of clock gene rhythmicity.

  19. A systems dynamics approach for supporting regional decisions on the energetic use of regional biomass residues.

    Science.gov (United States)

    Szarka, Nora; Wolfbauer, Jürgen; Bezama, Alberto

    2018-02-01

    This article presents the definition, building, calibration and application of a system dynamics simulation model to quantify the present and future comparative advantages and disadvantages of using forest and agricultural residual biomass for energetic purpose through different processes and technologies, on a regional basis. A dynamic structure of the agricultural and forestry biomass process activities (i.e. production, transport, conversion and consumption) based on regional time-series data was built, implemented into and calibrated within a dynamic simulation tool (Vensim software) within a Hungarian county. Besides the agriculture and forestry sectors, the model includes data about demography, economy, environment and land use, among others. For carrying out the assessment, realistic scenarios of future biomass processes and of biomass use were formulated, characterised by quantitative sustainable development indicators and simulated within the dynamic model. The results prove that the introduced model supports decision making of biomass utilisation in a regional scale, through comparing and analysing quantitative changes of economic, social and environment indicators, which characterise a sustainable regional development. The model therefore allows analyses and evaluation of not only partial prosperous or adverse characteristics of biomass processes and use, but also to relate regional components and their development over time. The developed dynamic tool is therefore a powerful method to model complex systems, such as a regional energy system, considering the framework of the regional preferences stated by the regional stakeholders. It can thus provide useful decision support, especially when used as a priority-based screening of potential regional development programmes in the energy field.

  20. Circadian oscillators in the mouse brain

    DEFF Research Database (Denmark)

    Rath, Martin F; Rovsing, Louise; Møller, Morten

    2014-01-01

    The circadian timekeeper of the mammalian brain resides in the suprachiasmatic nucleus of the hypothalamus (SCN), and is characterized by rhythmic expression of a set of clock genes with specific 24-h daily profiles. An increasing amount of data suggests that additional circadian oscillators...... residing outside the SCN have the capacity to generate peripheral circadian rhythms. We have recently shown the presence of SCN-controlled oscillators in the neocortex and cerebellum of the rat. The function of these peripheral brain clocks is unknown, and elucidating this could involve mice...... and granular cell layers of the cerebellar cortex of the mouse brain. Among these, Per1, Per2, Cry1, Arntl, and Nr1d1 exhibit circadian rhythms suggesting that local running circadian oscillators reside within neurons of the mouse neocortex and cerebellar cortex. The temporal expression profiles of clock genes...

  1. 75 FR 45640 - Draft Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems...

    Science.gov (United States)

    2010-08-03

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-D-0246] Draft Guidance for Industry on Residual Drug in Transdermal and Related Drug Delivery Systems; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug...

  2. Field evaluations of residual pesticide applications and misting system on militarily relevant materials against medically important mosquitoes in Thailand

    Science.gov (United States)

    A key strategy to reduce insect-borne disease is to reduce contact between disease vectors and hosts. In the current study, residual pesticide application and misting system were applied on militarily relevant materials and evaluated against medically important mosquitoes. Field evaluations were car...

  3. The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

    Science.gov (United States)

    Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

    2018-01-01

    The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ-quanta by the residuals in the activated structures and scoring the prompt doses of these γ-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

  4. On the Generation of a Robust Residual for Closed-loopControl systems that Exhibit Sensor Faults

    DEFF Research Database (Denmark)

    Alavi, Seyed Mohammad Mahdi; Izadi-Zamanabadi, Roozbeh; Hayes, Martin J.

    2007-01-01

    This paper presents a novel design methodology, based on shaping the system frequency response, for the generation of an appropriate residual signal that is sensitive to sensor faults in the presence of model uncertainty and exogenous unknown (unmeasured) disturbances. An integrated feedback cont...

  5. The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

    Energy Technology Data Exchange (ETDEWEB)

    Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

    2018-01-01

    The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

  6. Investigating the Composite Step Biconjugate A-Orthogonal Residual Method for Non-Hermitian Dense Linear Systems in Electromagnetics

    NARCIS (Netherlands)

    Jing, Yan-Fei; Huang, Ting-Zhu; Carpentieri, Bruno; Duan, Yong

    An interesting stabilizing variant of the biconjugate A-orthogonal residual (BiCOR) method is investigated for solving dense complex non-Hermitian systems of linear equations arising from the Galerlcin discretization of surface integral equations in electromagnetics. The novel variant is naturally

  7. Circadian variation in defibrillation energy requirements.

    Science.gov (United States)

    Venditti, F J; John, R M; Hull, M; Tofler, G H; Shahian, D M; Martin, D T

    1996-10-01

    Reports have demonstrated a circadian variation in the incidence of acute myocardial infarction, ventricular arrhythmias, and sudden cardiac death. We tested the hypothesis that a similar circadian variation exists for defibrillation energy requirements in humans. We reviewed the time of defibrillation threshold (DFT) measurements in 134 patients with implantable cardioverter-defibrillators (ICDs) who underwent 345 DFT measurements. The DFT was determined in 130 patients at implantation, in 121 at a 2 months, and in 94 at 6 months. All patients had nonthoracotomy systems. The morning DFT (8 AM to 12 noon) was 15.1 +/- 1.2 J compared with 13.1 +/- 0.9 J in the midafternoon (12 noon to 4 PM) and 13.0 +/- 0.7 J in the late afternoon (4 to 8 PM), P < .02. In a separate group of 930 patients implanted with an ICD system with date and time stamps for each therapy, we reviewed 1238 episodes of ventricular tachyarrhythmias treated with shock therapy. To corroborate the hypothesis that energy requirements for arrhythmia termination vary during the course of the day, we plotted the failed first shock frequency for all episodes per hour. There was a significant peak in failed first shocks in the morning compared with other time intervals (P = .02). There is a morning peak in DFT and a corresponding morning peak in failed first shock frequency. This morning peak resembles the peaks seen in other cardiac events, specifically sudden cardiac death. These findings have important implications for appropriate ICD function, particularly in patients with marginal DFTs.

  8. WNT Takes Two to Tango: Molecular Links between the Circadian Clock and the Cell Cycle in Adult Stem Cells.

    Science.gov (United States)

    Matsu-Ura, Toru; Moore, Sean R; Hong, Christian I

    2018-02-01

    Like two dancers, the circadian clock and cell cycle are biological oscillators engaged in bidirectional communication, resulting in circadian clock-gated cell division cycles in species ranging from cyanobacteria to mammals. The identified mechanisms for this phenomenon have expanded beyond intracellular molecular coupling components to include intercellular connections. However, detailed molecular mechanisms, dynamics, and physiological functions of the circadian clock and cell cycle as coupled oscillators remain largely unknown. In this review, we discuss current understanding of this connection in light of recent findings that have uncovered intercellular coupling between the circadian clock in Paneth cells and the cell cycle in intestinal stem cells via WNT signaling. This extends the impact of circadian rhythms regulating the timing of cell divisions beyond the intracellular domain of homogenous cell populations into dynamic, multicellular systems. In-depth understanding of the molecular links and dynamics of these two oscillators will identify potential targets and temporal regimens for effective chronotherapy.

  9. Polyporus and Bupleuri radix effectively alter peripheral circadian clock phase acutely in male mice.

    Science.gov (United States)

    Motohashi, Hiroaki; Sukigara, Haruna; Tahara, Yu; Saito, Keisuke; Yamazaki, Mayu; Shiraishi, Takuya; Kikuchi, Yosuke; Haraguchi, Atsushi; Shibata, Shigenobu

    2017-07-01

    In mammals, daily physiological events are precisely regulated by an internal circadian clock system. An important function of this system is to readjust the phase of the clock daily. In Japan, traditional herb medicines, so-called crude drugs (Shoyaku), are widely used for many diseases, and some are reported to affect circadian clock impairment, suggesting that some of them might have an ability to modify clock gene expression rhythms. Therefore, from selected 40 crude drugs, finding candidates that control the circadian clock phases was the first purpose of this study. As there are several crude drugs used for liver- and/or kidney-related diseases, the second aim of the present study was to find some crude drugs affecting liver/kidney circadian clock in vivo. To assess phase changes in the daily circadian rhythm, bioluminescence from the core clock gene product Period 2 was continuously monitored in mouse embryonic fibroblasts in vitro and in some peripheral tissues (kidney, liver, and submandibular gland) of PERIOD2::LUCIFERASE knock-in mice in vivo. In our screening, Polyporus and Bupleuri radix were found to be good candidates to effectively manipulate the peripheral circadian clock phase acutely, with stimulation time-of-day dependency in vitro as well as in vivo. Interestingly, Polyporus and Bupleuri radix are traditional herb medicines use for treating edema and promoting diuresis, and for chronic hepatitis, respectively. These crude drugs may be therefore good modulators of the circadian peripheral clocks including liver and kidney, and circadian clock genes become new molecular targets for these crude drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Effect of circadian phase on memory acquisition and recall: operant conditioning vs. classical conditioning.

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    Madeleine V Garren

    Full Text Available There have been several studies on the role of circadian clocks in the regulation of associative learning and memory processes in both vertebrate and invertebrate species. The results have been quite variable and at present it is unclear to what extent the variability observed reflects species differences or differences in methodology. Previous results have shown that following differential classical conditioning in the cockroach, Rhyparobia maderae, in an olfactory discrimination task, formation of the short-term and long-term memory is under strict circadian control. In contrast, there appeared to be no circadian regulation of the ability to recall established memories. In the present study, we show that following operant conditioning of the same species in a very similar olfactory discrimination task, there is no impact of the circadian system on either short-term or long-term memory formation. On the other hand, ability to recall established memories is strongly tied to the circadian phase of training. On the basis of these data and those previously reported for phylogenetically diverse species, it is suggested that there may be fundamental differences in the way the circadian system regulates learning and memory in classical and operant conditioning.

  11. Linking Energy- and Land-Use Systems: Energy Potentials and Environmental Risks of Using Agricultural Residues in Tanzania

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    Julia C. Terrapon-Pfaff

    2012-02-01

    Full Text Available This paper attempts to assess whether renewable energy self-sufficiency can be achieved in the crop production and processing sector in Tanzania and if this could be accomplished in an environmentally sustainable manner. In order to answer these questions the theoretical energy potential of process residues from commercially produced agricultural crops in Tanzania is evaluated. Furthermore, a set of sustainability indicators with focus on environmental criteria is applied to identify risks and opportunities of using these residues for energy generation. In particular, the positive and negative effects on the land-use-system (soil fertility, water use and quality, biodiversity, etc. are evaluated. The results show that energy generation with certain agricultural process residues could not only improve and secure the energy supply but could also improve the sustainability of current land-use practices.

  12. Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

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    D. Singh

    2017-11-01

    Full Text Available Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle–γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with ‘fast’ α and 2α-emission channels are found to be entirely different from fusion–evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

  13. CLOCK Genes and Circadian Rhythmicity in Alzheimer Disease

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    J. Thome

    2011-01-01

    Full Text Available Disturbed circadian rhythms with sleep problems and disrupted diurnal activity are often seen in patients suffering from Alzheimer disease (AD. Both endogenous CLOCK genes and external Zeitgeber are responsible for the maintenance of circadian rhythmicity in humans. Therefore, modifications of the internal CLOCK system and its interactions with exogenous factors might constitute the neurobiological basis for clinically observed disruptions in rhythmicity, which often have grave consequences for the quality of life of patients and their caregivers. Presently, more and more data are emerging demonstrating how alterations of the CLOCK gene system might contribute to the pathophysiology of AD and other forms of dementia. At the same time, the impact of neuropsychiatric medication on CLOCK gene expression is under investigation.

  14. Analysis of plastic residues in maple sap and syrup collected from tubing systems sanitized with isopropyl alcohol

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    Luc Lagacé

    2017-05-01

    Full Text Available A plastic tubing system operated under vacuum is usually used to collect sap from maple trees during spring time to produce maple syrup. This system is commonly sanitized with isopropyl alcohol (IPA to remove microbial contamination colonizing the system during the sugar season. Questions have been raised whether IPA would contribute to the leaching of plastic residues in maple sap and syrup coming from sanitized systems. First, an extraction experiment was performed in the lab on commercial plastic tubing materials that were submitted to IPA under harsh conditions. The results of the GC-MS analysis revealed the presence of many compounds that served has target for further tests. Secondly, tests were done on early and mid-season maple sap and syrup coming from many sugarbushes using IPA or not to determine potential concentrations of plastic residues. Results obtained from sap and syrup samples showed that no quantifiable (< 1–75 μg/L concentration of any plastic molecules tested was determined in all samples coming from IPA treated or not treated systems. However, some samples of first sap run used as a rinse solution to be discarded before the season start and that were coming from non sanitized or IPA sanitized systems, showed quantifiable concentrations of chemical residue such as ultraviolet protector (octabenzone. These results show that IPA can be safely used to sanitize maple sap collection system in regards to the leaching of plastic residues in maple sap and syrup and reinforced the need to thoroughly rinse the tubing system at the beginning of the season for both sanitized and non sanitized systems.

  15. Aging has the opposite effect on cAMP and cGMP circadian variations in rat Leydig cells.

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    Baburski, Aleksandar Z; Sokanovic, Srdjan J; Andric, Silvana A; Kostic, Tatjana S

    2017-05-01

    The Leydig cell physiology displays a circadian rhythm driven by a complex interaction of the reproductive axis hormones and circadian system. The final output of this regulatory process is circadian pattern of steroidogenic genes expression and testosterone production. Aging gradually decreases robustness of rhythmic testosterone secretion without change in pattern of LH secretion. Here, we analyzed effect of aging on circadian variation of cAMP and cGMP signaling in Leydig cells. Results showed opposite effect of aging on cAMP and cGMP daily variation. Reduced amplitude of cAMP circadian oscillation was probably associated with changed expression of genes involved in cAMP production (increased circadian pattern of Adcy7, Adcy9, Adcy10 and decreased Adcy3); cAMP degradation (increased Pde4a, decreased Pde8b, canceled rhythm of Pde4d, completely reversed circadian pattern of Pde7b and Pde8a); and circadian expression of protein kinase A subunits (Prkac/PRKAC and Prkar2a). Aging stimulates expression of genes responsible for cGMP production (Nos2, Gucy1a3 and Gucy1b3/GUCYB3) and degradation (Pde5a, Pde6a and Pde6h) but the overall net effect is elevation of cGMP circadian oscillations in Leydig cells. In addition, the expression of cGMP-dependent kinase, Prkg1/PRKG1 is up-regulated. It seems that aging potentiate cGMP- and reduce cAMP-signaling in Leydig cells. Since both signaling pathways affect testosterone production and clockwork in the cells, further insights into these signaling pathways will help to unravel disorders linked to the circadian timing system, aging and reproduction.

  16. Effects of microgravity on circadian rhythms in insects

    Science.gov (United States)

    Alpatov, A. M.; Hoban-Higgins, T. M.; Fuller, C. A.; Lazarev, A. O.; Rietveld, W. J.; Tschernyshev, V. B.; Tumurova, E. G.; Wassmer, G.; Zotov, V. A.

    1998-01-01

    The desert beetle Trigonoscelis gigas Reitt. was used as a biological model in studies that examined the effects of space flight on the circadian timing system. Results from studies aboard the Bion-10, Bion-11, and Photon-11 missions are reported. The control study is an ongoing Mir experiment. The studies indicate that the free-running period in beetles may be longer during space flight.

  17. Mathematical Models of the Circadian Sleep-Wake Cycle.

    Science.gov (United States)

    1984-05-01

    may also be involved in adjustments of sleep -wake periodicity to conscious or subconscious habits , to shiftwork, and to Wever’s forced- sleep schedules...probably keeps running under LD control. Such force of external conditions and daily habits may affect the threshold system such that sleep ...A0 A145 712 MAIHEMATICAL MODELS Or ItE CIRCADIAN SLEEP -WAKE CYCLE i/ ll HARVARD MEDICAL SCHOOL BOSTON MA DEPT OF PHYSIOLOGY AND BIOPllVSICS U C MOORE

  18. Cryptochrome mediates light-dependent magnetosensitivity of Drosophila's circadian clock.

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    Taishi Yoshii

    2009-04-01

    Full Text Available Since 1960, magnetic fields have been discussed as Zeitgebers for circadian clocks, but the mechanism by which clocks perceive and process magnetic information has remained unknown. Recently, the radical-pair model involving light-activated photoreceptors as magnetic field sensors has gained considerable support, and the blue-light photoreceptor cryptochrome (CRY has been proposed as a suitable molecule to mediate such magnetosensitivity. Since CRY is expressed in the circadian clock neurons and acts as a critical photoreceptor of Drosophila's clock, we aimed to test the role of CRY in magnetosensitivity of the circadian clock. In response to light, CRY causes slowing of the clock, ultimately leading to arrhythmic behavior. We expected that in the presence of applied magnetic fields, the impact of CRY on clock rhythmicity should be altered. Furthermore, according to the radical-pair hypothesis this response should be dependent on wavelength and on the field strength applied. We tested the effect of applied static magnetic fields on the circadian clock and found that flies exposed to these fields indeed showed enhanced slowing of clock rhythms. This effect was maximal at 300 muT, and reduced at both higher and lower field strengths. Clock response to magnetic fields was present in blue light, but absent under red-light illumination, which does not activate CRY. Furthermore, cry(b and cry(OUT mutants did not show any response, and flies overexpressing CRY in the clock neurons exhibited an enhanced response to the field. We conclude that Drosophila's circadian clock is sensitive to magnetic fields and that this sensitivity depends on light activation of CRY and on the applied field strength, consistent with the radical pair mechanism. CRY is widespread throughout biological systems and has been suggested as receptor for magnetic compass orientation in migratory birds. The present data establish the circadian clock of Drosophila as a model system

  19. Circadian health differs between boys and girls as assessed by non-invasive tools in school-aged children.

    Science.gov (United States)

    Barraco, Gloria Maria; Martínez-Lozano, Nuria; Vales-Villamarín, Claudia; Del Carmen Blaya, María; Rios, Rafael; Madrid, Juan Antonio; Fardy, Paul; Garaulet, Marta

    2018-03-21

    Assessment of circadian health is confined to adults. However, understanding circadian status of school-aged children is necessary due to its health implications. The aim was to develop 1) a protocol to assess circadian function in school-aged children by combining the best non-invasive tools previously validated in adults; 2) a score to capture circadian function in children including food timing. This protocol will allow to explore gender differences and to compare the circadian function of school-aged children with adults from the same Mediterranean area. Healthy children (8-12 y) from 3 schools in a Mediterranean area of Spain were recruited (n = 248; 125 males and 123 females). Several non-invasive tools were used: a) 7-day-diaries of food timing and food intake, physical-activity and sleep, b) Munich-chronotype-self-reported-questionnaire; c) cortisol and melatonin saliva determinations; d) 7-day-rhythms of wrist temperature (T), activity (A), position (P) and the integrative variable TAP e) 7-day-light exposure. We have constructed the first school-aged children population for the assessment of circadian function (ONTIME-Jr) and a new circadian score has been developed. Among circadian-related measures, TAP was the most suitable and reliable to determine circadian system characteristics. Circadian function was better in girls than in boys [circadian score (AU) Mean ± SD (girls, 1216 ± 153 vs. 1159 ± 173 boys, P = 0.012)], and also in school-aged children than in adults from the same Mediterranean area (Circadian-Function-Index: children 0.47 ± 0.06 vs. adults 0.45 ± 0.06 P = 0.001). A new protocol, including TAP and food timing, demonstrated to be reliable in assessing circadian function in children. These non-invasive techniques provide the wherewithal for paediatricians to assess circadian function in clinical practice. Chronobiology and childhood obesity (ONTIME-Jr: Obesity, Nutrigenetics, Timing and Mediterranean, Junior). Clinical

  20. An autonomous circadian clock in the inner mouse retina regulated by dopamine and GABA.

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    Guo-Xiang Ruan

    2008-10-01

    Full Text Available The influence of the mammalian retinal circadian clock on retinal physiology and function is widely recognized, yet the cellular elements and neural regulation of retinal circadian pacemaking remain unclear due to the challenge of long-term culture of adult mammalian retina and the lack of an ideal experimental measure of the retinal circadian clock. In the current study, we developed a protocol for long-term culture of intact mouse retinas, which allows retinal circadian rhythms to be monitored in real time as luminescence rhythms from a PERIOD2::LUCIFERASE (PER2::LUC clock gene reporter. With this in vitro assay, we studied the characteristics and location within the retina of circadian PER2::LUC rhythms, the influence of major retinal neurotransmitters, and the resetting of the retinal circadian clock by light. Retinal PER2::LUC rhythms were routinely measured from whole-mount retinal explants for 10 d and for up to 30 d. Imaging of vertical retinal slices demonstrated that the rhythmic luminescence signals were concentrated in the inner nuclear layer. Interruption of cell communication via the major neurotransmitter systems of photoreceptors and ganglion cells (melatonin and glutamate and the inner nuclear layer (dopamine, acetylcholine, GABA, glycine, and glutamate did not disrupt generation of retinal circadian PER2::LUC rhythms, nor did interruption of intercellular communication through sodium-dependent action potentials or connexin 36 (cx36-containing gap junctions, indicating that PER2::LUC rhythms generation in the inner nuclear layer is likely cell autonomous. However, dopamine, acting through D1 receptors, and GABA, acting through membrane hyperpolarization and casein kinase, set the phase and amplitude of retinal PER2::LUC rhythms, respectively. Light pulses reset the phase of the in vitro retinal oscillator and dopamine D1 receptor antagonists attenuated these phase shifts. Thus, dopamine and GABA act at the molecular level of PER

  1. Identification of the molecular components of a Tigriopus californicus (Crustacea, Copepoda) circadian clock.

    Science.gov (United States)

    Nesbit, Katherine T; Christie, Andrew E

    2014-12-01

    Copepods of the genus Tigriopus have been proposed as marine models for investigations of environmental perturbation. One rapidly increasing anthropogenic stressor for intertidal organisms is light pollution. Given the sensitivity of circadian rhythms to exogenous light, the genes/proteins of a Tigriopus circadian pacemaker represent a potential system for investigating the influences of artificial light sources on circadian behavior in an intertidal species. Here, the molecular components of a putative Tigriopus californicus circadian clock were identified using publicly accessible transcriptome data; the recently deduced circadian proteins of the copepod Calanus finmarchicus were used as a reference. Transcripts encoding homologs of all commonly recognized ancestral arthropod core clock proteins were identified (i.e. CLOCK, CRYPTOCHROME 2, CYCLE, PERIOD and TIMELESS), as were ones encoding proteins likely to modulate the core clock (i.e. CASEIN KINASE II, CLOCKWORK ORANGE, DOUBLETIME, PROTEIN PHOSPHATASE 1, PROTEIN PHOSPHATASE 2A, SHAGGY, SUPERNUMERARY LIMBS and VRILLE) or to act as inputs to it (i.e. CRYPTOCHROME 1). PAR DOMAIN PROTEIN 1 was the only circadian-associated protein not identified in Tigriopus; it appears absent in Calanus too. These data represent just the third full set of molecular components for a crustacean circadian pacemaker (Daphnia pulex and C. finmarchicus previously), and only the second obtained from transcribed sequences (C. finmarchicus previously). Given Tigriopus' proposed status as a model for investigating the influences of anthropogenic stressors in the marine environment, these data provide the first suite of gene/protein targets for understanding how light pollution may influence circadian physiology and behavior in an intertidal organism. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Direct Repression of Evening Genes by CIRCADIAN CLOCK-ASSOCIATED1 in the Arabidopsis Circadian Clock.

    Science.gov (United States)

    Kamioka, Mari; Takao, Saori; Suzuki, Takamasa; Taki, Kyomi; Higashiyama, Tetsuya; Kinoshita, Toshinori; Nakamichi, Norihito

    2016-03-01

    The circadian clock is a biological timekeeping system that provides organisms with the ability to adapt to day-night cycles. Timing of the expression of four members of the Arabidopsis thaliana PSEUDO-RESPONSE REGULATOR(PRR) family is crucial for proper clock function, and transcriptional control of PRRs remains incompletely defined. Here, we demonstrate that direct regulation of PRR5 by CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) determines the repression state of PRR5 in the morning. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) analyses indicated that CCA1 associates with three separate regions upstream of PRR5 CCA1 and its homolog LATE ELONGATED HYPOCOTYL (LHY) suppressed PRR5 promoter activity in a transient assay. The regions bound by CCA1 in the PRR5 promoter gave rhythmic patterns with troughs in the morning, when CCA1 and LHY are at high levels. Furthermore,ChIP-seq revealed that CCA1 associates with at least 449 loci with 863 adjacent genes. Importantly, this gene set contains genes that are repressed but upregulated incca1 lhy double mutants in the morning. This study shows that direct binding by CCA1 in the morning provides strong repression of PRR5, and repression by CCA1 also temporally regulates an evening-expressed gene set that includes PRR5. © 2016 American Society of Plant Biologists. All rights reserved.

  3. Nitrógeno residual y lixiviado del fertilizante en el sistema suelo-planta-zeolitas Residual and leached nitrogen in soil plant zeolite systems

    Directory of Open Access Journals (Sweden)

    Gabriela Civeira

    2011-12-01

    -1 zeolite + 200 kg N ha-1, NZ2: 200 kg ha-1 zeolite + 200 kg N ha-1. At the maize silking (R1 stage, soil samples were taken to determine the residual N (NO3-N and N-NH4 and plant samples were obtained to measure dry matter (DM and N absorbed by the plant. The N use efficiency (NUE was also evaluated in each treatment. Finally, a forced leaching was applied in all treatments. The results showed that the application of N fertilizer with lower rates of zeolites (NZ1 significantly increased the N absorbed by maize, dry matter and NUE compared to the N treatment. These results can be explained by the favourable effect of the zeolites on nitrogen mineralization and soil water retention. The higher absorbed N levels in NZ1 corresponded with a significant residual N decrease compared to the N treatment while the leached N remained the same. Nevertheless, when the applied zeolites rate was higher (NZ2, the absorbed N by maize was similar to the N treatment while the leached N increased significantly compared to the N and NZ1 treatments, thus showing a late release of N to the soil solution. These results suggest that the synchronization between the pattern of N release from the soil-fertilizer-zeolite system and the N absorption by maize depended on the zeolite rate. While in NZ1 such synchronization improved the performance of the nitrogen fertilizer, in the NZ2 treatment the retained N by the zeolites was not available to maize, being detected as leached N at the end of the experiment.

  4. Principles for circadian orchestration of metabolic pathways

    Science.gov (United States)

    Thurley, Kevin; Herbst, Christopher; Wesener, Felix; Koller, Barbara; Wallach, Thomas; Maier, Bert; Kramer, Achim

    2017-01-01

    Circadian rhythms govern multiple aspects of animal metabolism. Transcriptome-, proteome- and metabolome-wide measurements have revealed widespread circadian rhythms in metabolism governed by a cellular genetic oscillator, the circadian core clock. However, it remains unclear if and under which conditions transcriptional rhythms cause rhythms in particular metabolites and metabolic fluxes. Here, we analyzed the circadian orchestration of metabolic pathways by direct measurement of enzyme activities, analysis of transcriptome data, and developing a theoretical method called circadian response analysis. Contrary to a common assumption, we found that pronounced rhythms in metabolic pathways are often favored by separation rather than alignment in the times of peak activity of key enzymes. This property holds true for a set of metabolic pathway motifs (e.g., linear chains and branching points) and also under the conditions of fast kinetics typical for metabolic reactions. By circadian response analysis of pathway motifs, we determined exact timing separation constraints on rhythmic enzyme activities that allow for substantial rhythms in pathway flux and metabolite concentrations. Direct measurements of circadian enzyme activities in mouse skeletal muscle confirmed that such timing separation occurs in vivo. PMID:28159888

  5. SKIP is a component of the spliceosome linking alternative splicing and the circadian clock in Arabidopsis.

    Science.gov (United States)

    Wang, Xiaoxue; Wu, Fangming; Xie, Qiguang; Wang, Huamei; Wang, Ying; Yue, Yanling; Gahura, Ondrej; Ma, Shuangshuang; Liu, Lei; Cao, Ying; Jiao, Yuling; Puta, Frantisek; McClung, C Robertson; Xu, Xiaodong; Ma, Ligeng

    2012-08-01

    Circadian clocks generate endogenous rhythms in most organisms from cyanobacteria to humans and facilitate entrainment to environmental diurnal cycles, thus conferring a fitness advantage. Both transcriptional and posttranslational mechanisms are prominent in the basic network architecture of circadian systems. Posttranscriptional regulation, including mRNA processing, is emerging as a critical step for clock function. However, little is known about the molecular mechanisms linking RNA metabolism to the circadian clock network. Here, we report that a conserved SNW/Ski-interacting protein (SKIP) domain protein, SKIP, a splicing factor and component of the spliceosome, is involved in posttranscriptional regulation of circadian clock genes in Arabidopsis thaliana. Mutation in SKIP lengthens the circadian period in a temperature-sensitive manner and affects light input and the sensitivity of the clock to light resetting. SKIP physically interacts with the spliceosomal splicing factor Ser/Arg-rich protein45 and associates with the pre-mRNA of clock genes, such as PSEUDORESPONSE REGULATOR7 (PRR7) and PRR9, and is necessary for the regulation of their alternative splicing and mRNA maturation. Genome-wide investigations reveal that SKIP functions in regulating alternative splicing of many genes, presumably through modulating recognition or cleavage of 5' and 3' splice donor and acceptor sites. Our study addresses a fundamental question on how the mRNA splicing machinery contributes to circadian clock function at a posttranscriptional level.

  6. The Trade-Off Mechanism in Mammalian Circadian Clock Model with Two Time Delays

    Science.gov (United States)

    Yan, Jie; Kang, Xiaxia; Yang, Ling

    Circadian clock is an autonomous oscillator which orchestrates the daily rhythms of physiology and behaviors. This study is devoted to explore how a positive feedback loop affects the dynamics of mammalian circadian clock. We simplify an experimentally validated mathematical model in our previous work, to a nonlinear differential equation with two time delays. This simplified mathematical model incorporates the pacemaker of mammalian circadian clock, a negative primary feedback loop, and a critical positive auxiliary feedback loop, Rev-erbα/Cry1 loop. We perform analytical studies of the system. Delay-dependent conditions for the asymptotic stability of the nontrivial positive steady state of the model are investigated. We also prove the existence of Hopf bifurcation, which leads to self-sustained oscillation of mammalian circadian clock. Our theoretical analyses show that the oscillatory regime is reduced upon the participation of the delayed positive auxiliary loop. However, further simulations reveal that the auxiliary loop can enable the circadian clock gain widely adjustable amplitudes and robust period. Thus, the positive auxiliary feedback loop may provide a trade-off mechanism, to use the small loss in the robustness of oscillation in exchange for adaptable flexibility in mammalian circadian clock. The results obtained from the model may gain new insights into the dynamics of biological oscillators with interlocked feedback loops.

  7. Dynamic circadian protein-protein interaction networks predict temporal organization of cellular functions.

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    Thomas Wallach

    2013-03-01

    Full Text Available Essentially all biological processes depend on protein-protein interactions (PPIs. Timing of such interactions is crucial for regulatory function. Although circadian (~24-hour clocks constitute fundamental cellular timing mechanisms regulating important physiological processes, PPI dynamics on this timescale are largely unknown. Here, we identified 109 novel PPIs among circadian clock proteins via a yeast-two-hybrid approach. Among them, the interaction of protein phosphatase 1 and CLOCK/BMAL1 was found to result in BMAL1 destabilization. We constructed a dynamic circadian PPI network predicting the PPI timing using circadian expression data. Systematic circadian phenotyping (RNAi and overexpression suggests a crucial role for components involved in dynamic interactions. Systems analysis of a global dynamic network in liver revealed that interacting proteins are expressed at similar times likely to restrict regulatory interactions to specific phases. Moreover, we predict that circadian PPIs dynamically connect many important cellular processes (signal transduction, cell cycle, etc. contributing to temporal organization of cellular physiology in an unprecedented manner.

  8. Detection and resolution of genetic loci affecting circadian period in Brassica oleracea.

    Science.gov (United States)

    Salathia, Neeraj; Lynn, James R; Millar, Andrew J; King, Graham J

    2007-02-01

    Circadian rhythms regulate many aspects of plant growth, fitness and vigour. The components and detailed mechanism of circadian regulation to date have been dissected in the reference species Arabidopsis thaliana. To determine the genetic basis and range of natural allelic variation for intrinsic circadian period in the closest crop relatives, we used an accurate and high throughput data capture system to record rhythmic cotyledon movement in two immortal segregating populations of Brassica oleracea, derived from parent lines representing different crop types. Periods varied between 24.4 and 26.1 h between the parent lines, with transgressive segregation between extreme recombinant lines in both populations of approximately 3.5 h. The additive effect of individual QTL identified in each population varied from 0.17 to 0.36 h. QTL detected in one doubled haploid population were verified and the mapping intervals further resolved by determining circadian period in genomic substitution lines derived from the parental lines. Comparative genomic analysis based on collinearity between Brassica and Arabidopsis also allowed identification of candidate orthologous genes known to regulate period in Arabidopsis, that may account for the additive circadian effects of specific QTL. The distinct QTL positions detected in the two populations, and the extent of transgressive segregation suggest that there is likely to be considerable scope for modulating the range of available circadian periods in natural populations and crop species of Brassica. This may provide adaptive advantage for optimising growth and development in different latitudes, seasons or climate conditions.

  9. Chronic cocaine causes long-term alterations in circadian period and photic entrainment in the mouse.

    Science.gov (United States)

    Stowie, A C; Amicarelli, M J; Prosser, R A; Glass, J D

    2015-01-22

    The disruptive effects of cocaine on physiological, behavioral and genetic processes are well established. However, few studies have focused on the actions of cocaine on the adult circadian timekeeping system, and none have explored the circadian implications of long-term (weeks to months) cocaine exposure. The present study was undertaken to explore the actions of such long-term cocaine administration on core circadian parameters in mice, including rhythm period, length of the nocturnal activity period and photic entrainment. For cocaine dosing over extended periods, cocaine was provided in drinking water using continuous and scheduled regimens. The impact of chronic cocaine on circadian regulation was evidenced by disruptions of the period of circadian entrainment and intrinsic free-running circadian period. Specifically, mice under a skeleton photoperiod (1-min pulse of dim light delivered daily) receiving continuous ad libitum cocaine entrained rapidly to the light pulse at activity onset. Conversely, water controls entrained more slowly at activity offset through a process of phase-delays, which resulted in their activity rhythms being entrained 147° out of phase with the cocaine group. This pattern persisted after cocaine withdrawal. Next, mice exposed to scheduled daily cocaine presentations exhibited free-running periods under constant darkness that were significantly longer than water controls and which also persisted after cocaine withdrawal. These cocaine-induced perturbations of clock timing could produce chronic psychological and physiological stress, contributing to increased cocaine use and dependence. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Mini screening of kinase inhibitors affecting period-length of mammalian cellular circadian clock.

    Science.gov (United States)

    Yagita, Kazuhiro; Yamanaka, Iori; Koinuma, Satoshi; Shigeyoshi, Yasufumi; Uchiyama, Yasuo

    2009-06-27

    In mammalian circadian rhythms, the transcriptional-translational feedback loop (TTFL) consisting of a set of clock genes is believed to elicit the circadian clock oscillation. The TTFL model explains that the accumulation and degradation of mPER and mCRY proteins control the period-length (tau) of the circadian clock. Although recent studies revealed that the Casein Kinase I epsilon delta (CKI epsilon delta) regulates the phosphorylation of mPER proteins and the circadian period-length, other kinases are also likely to contribute the phosphorylation of mPER. Here, we performed small scale screening using 84 chemical compounds known as kinase inhibitors to identify candidates possibly affecting the circadian period-length in mammalian cells. Screening by this high-throughput real-time bioluminescence monitoring system revealed that the several chemical compounds apparently lengthened the cellular circadian clock oscillation. These compounds are known as inhibitors against kinases such as Casein Kinase II (CKII), PI3-kinase (PI3K) and c-Jun N-terminal Kinase (JNK) in addition to CKI epsilon delta. Although these kinase inhibitors may have some non-specific effects on other factors, our mini screening identified new candidates contributing to period-length control in mammalian cells.

  11. Effect of Tillage Systems with Corn Residue on Grain Yield of Rapeseed in Moghan Region

    Directory of Open Access Journals (Sweden)

    J Taghinazhad

    2014-09-01

    Full Text Available This study carried out to evaluate the effect of different tillage systems on rapeseed yield (hayola 401 planted in corn residues. This experiment was done in Moghan region with clay soils during 2009-2012. Different seedbed preparation methods include MT: moldboard + disk tillage (conventional tillage was included, SCT: Stem Crusher + chisel + disk tandem harrow, STT: Stem Crusher + double-disc, CT: chisel + disk tillage and DD: two heavy disks. The experiment was conducted in a randomized complete block design with four replications. The results showed that soil bulk density in the 0-10 cm layer was not significant in different tillage treatments, but it was significantly higher than the conventional tillage in 10-20 cm depth. However, penetration resistance in 10-30 cm under DD was significantly higher than other treatments, but it was not significant in 0-10 cm layer among all tillage treatments. Thus, Comparison of the soil bulk density, penetration resistance, and plant establishment showed that the reduced tillage in canola seedbed preparation was effective. Besides, the surveys indicated that there was a significant different between MWD after primary and secondary tillage. The mean diameter weighted under SCT and DD, were 1.19 and 1.24 cm, respectively had the best status. The highest value and the worst status of this parameter observed for MT which was 1.92 cm. The highest rate of grain yield obtained by application of treatment SCT, and it was 2563.8 kg ha-1, The SCT treatment can be recommended as an effective canola bed preparation due to its significant saving in time and cost after corn harvesting.

  12. Fertilizer nitrogen recovery efficiencies in crop production systems of China with and without consideration of the residual effect of nitrogen

    International Nuclear Information System (INIS)

    Yan, Xiaoyuan; Ti, Chaopu; Zhu, Zhaoliang; Vitousek, Peter; Chen, Deli; Leip, Adrian; Cai, Zucong

    2014-01-01

    China is the world’s largest consumer of synthetic nitrogen (N), where very low rates of fertilizer N recovery in crops have been reported, raising discussion around whether fertilizer N use can be significantly reduced without yield penalties. However, using recovery rates as indicator ignores a possible residual effect of fertilizer N—a factor often unknown at large scales. Such residual effect might store N in the soil increasing N availability for subsequent crops. The objectives of the present study were therefore to quantify the residual effect of fertilizer N in China and to obtain more realistic rates of the accumulative fertilizer N recovery efficiency (RE) in crop production systems of China. Long-term spatially-extensive data on crop production, fertilizer N and other N inputs to croplands in China were used to analyze the relationship between crop N uptake and fertilizer N input (or total N input), and to estimate the amount of residual fertilizer N. Measurement results of cropland soil N content in two time periods were obtained to compare the change in the soil N pool. At the provincial scale, it was found that there is a linear relationship between crop N uptake and fertilizer N input or total N input. With the increase in fertilizer N input, annual direct fertilizer N RE decreased and was indeed low (below 30% in recent years), while its residual effect increased continuously, to the point that 40–68% of applied fertilizer was used for crop production sooner or later. The residual effect was evidenced by a buildup of soil N and a large difference between nitrogen use efficiencies of long-term and short-term experiments. (paper)

  13. Quantifying the residual volume transport through a multiple-inlet system in response to wind forcing: The case of the western Dutch Wadden Sea

    NARCIS (Netherlands)

    Duran-Matute, M.; Gerkema, T.; Sassi, M.

    2016-01-01

    In multiple-inlet coastal systems like the western Dutch Wadden Sea, the tides (and their interaction with the bathymetry), the fresh water discharge, and the wind drive a residual flow through the system. In the current paper, we study the effect of the wind on the residual volume transport through

  14. Circadian integration of metabolism and energetics.

    Science.gov (United States)

    Bass, Joseph; Takahashi, Joseph S

    2010-12-03

    Circadian clocks align behavioral and biochemical processes with the day/night cycle. Nearly all vertebrate cells possess self-sustained clocks that couple endogenous rhythms with changes in cellular environment. Genetic disruption of clock genes in mice perturbs metabolic functions of specific tissues at distinct phases of the sleep/wake cycle. Circadian desynchrony, a characteristic of shift work and sleep disruption in humans, also leads to metabolic pathologies. Here, we review advances in understanding the interrelationship among circadian disruption, sleep deprivation, obesity, and diabetes and implications for rational therapeutics for these conditions.

  15. Nutrient retention capabilities of Nile tilapia ( Oreochromis niloticus) fed bio-regenerative life support system (BLSS) waste residues

    Science.gov (United States)

    Gonzales, John M.; Brown, Paul B.

    Nile tilapia were evaluated as a bio-regenerative sub-process for reducing solid waste potentially encountered in bio-regenerative life support systems. Ten juvenile Nile tilapia (mean weight = 2.05 g) were stocked into triplicate aquaria and fed one of seven experimental diets consisting of vegetable, bacterial, or food waste for a period of seven weeks. Weight gain (g), specific growth rate (mg/d), and daily consumption (g) was significantly higher ( p diet (37.99 and 68.54, respectively) followed by fish fed the wheat bran/wheat germ diet (23.19 and 63.67, respectively). Nitrogen, sulfur, and crude protein retention was significantly higher ( p diet (23.68, 21.89, and 23.68, respectively). A general loss of minerals was observed among all groups. Strong associations were observed between crude lipid retention and sulfur retention ( r2 = 0.94), crude lipid retention and carbon retention ( r2 = 0.92), WG and fiber content of dietary treatments ( r2 = 0.92), WG and carbon retention and ( r2 = 0.88), WG and lysine content of waste residues ( r2 = 0.86), crude protein retention and carbon retention ( r2 = 0.84), sulfur retention and crude protein retention ( r2 = 0.84), and total sulfur amino acid (TSAA) content of residues and WG ( r2 = 0.81). Weaker associations existed between WG and crude lipid retention ( r2 = 0.77), crude fiber content and carbon retention ( r2 = 0.76), and WG and methionine content of waste residues ( r2 = 0.75). Additional research is needed to improve the nutritional quality of fibrous residues as a means to improve tilapia's ability to utilize these residues as a food source in bio-regenerative support systems.

  16. Evaluation of certain crop residues for carbohydrate and protein fractions by cornell net carbohydrate and protein system

    Directory of Open Access Journals (Sweden)

    Venkateswarulu Swarna

    2015-06-01

    Full Text Available Four locally available crop residues viz., jowar stover (JS, maize stover (MS, red gram straw (RGS and black gram straw (BGS were evaluated for carbohydrate and protein fractions using Cornell Net Carbohydrate and Protein (CNCP system. Lignin (% NDF was higher in legume straws as compared to cereal stovers while Non-structural carbohydrates (NSC (% DM followed the reverse trend. The carbohydrate fractions A and B1 were higher in BGS while B2 was higher in MS as compared to other crop residues. The unavailable cell wall fraction (C was higher in legume straws when compared to cereal stovers. Among protein fractions, B1 was higher in legume straws when compared to cereal stovers while B2 was higher in cereal stovers as compared to legume straws. Fraction B3 largely, bypass protein was highest in MS as compared to other crop residues. Acid detergent insoluble crude protein (ADICP (% CP or unavailable protein fraction C was lowest in MS and highest in BGS. It is concluded that MS is superior in nutritional value for feeding ruminants as compared to other crop residues.

  17. Harvest time residues of pendimethalin and oxyfluorfen in vegetables and soil in sugarcane-based intercropping systems.

    Science.gov (United States)

    Kaur, Navneet; Bhullar, Makhan S

    2015-05-01

    Terminal residues of pendimethalin and oxyfluorfen applied in autumn sugarcane- and vegetables-based intercropping systems were analyzed in peas (Pisum sativum), cabbage (Brassica oleracea), garlic (Allium sativum), gobhi sarson (Brassica napus), and raya (Brassica juncea). The study was conducted in winter season in 2010-2011 and in 2011-2012 at Ludhiana, India. Pendimethalin at 0.56 kg and 0.75 kg ha(-1) was applied immediately after sowing of gobhi sarson, raya, peas, garlic, and 2 days before transplanting of cabbage seedlings. Oxyfluorfen at 0.17 kg and 0.23 kg ha(-1) was applied immediately after sowing of peas and garlic and 2 days before transplanting of cabbage seedlings intercropped in autumn sugarcane. Representative samples of these vegetables were collected at 75, 90, 100, and 165 days after application of herbicides and analyzed by high-performance liquid chromatograph (HPLC) with diode array detector for residues. The residue level of pendimethalin and oxyfluorfen in mature vegetables was found to be below the limit of quantification which is 0.05 mg kg(-1) for both the herbicides. The soil samples were collected at 0, 7, 15, 30, 45, and 60 days after the application of their herbicides. The residues of herbicides in soil samples were found to be below the detectability limit of 0.05 mg kg(-1) after 60 days in case of pendimethalin and after 45 days in case of oxyfluorfen.

  18. REST: a computer system for estimating logging residue by using the line-intersect method

    Science.gov (United States)

    A. Jeff Martin

    1975-01-01

    A computer program was designed to accept logging-residue measurements obtained by line-intersect sampling and transform them into summaries useful for the land manager. The features of the program, along with inputs and outputs, are briefly described, with a note on machine compatibility.

  19. Formation of residual NAPL in three-phase systems: Experiments and numerical simulations

    NARCIS (Netherlands)

    Hofstee, C.; Oostrom, M.

    2002-01-01

    The formation of residual, discontinuous nonaqueous phase liquids (NAPLs) in the vadose zone is a process that is not well understood. The simulators have conveniently implemented the Leverett concept (Leverett and Lewis, 1941) which states that in a water-wet porous media, when fluid wettabilities

  20. Behaviour of phenyl-urea type herbicides and related chemical residues in soil-plant systems

    International Nuclear Information System (INIS)

    Suess, A.; Eben, C.

    1975-01-01

    Uniformly 14 C-labelled aniline derivatives were used to indicate the degradation of phenyl-urea type herbicides. The results suggested cleavage of the benzene ring when present as a soil residue, cleavage apparently being reduced by increased chlorination of the ring. (author)

  1. Scalar position in cochlear implant surgery and outcome in residual hearing and the vestibular system.

    Science.gov (United States)

    Nordfalk, Karl Fredrik; Rasmussen, Kjell; Hopp, Einar; Greisiger, Ralf; Jablonski, Greg Eigner

    2014-02-01

    To evaluate the effect of the intracochlear electrode position on the residual hearing and VNG- and cVEMP responses. Prospective pilot study. Thirteen adult patients who underwent unilateral cochlear implant surgery were examined with high-resolution rotational tomography after cochlear implantation. All subjects were also tested with VNG, and 12 of the subjects were tested with cVEMP and audiometry before and after surgery. We found that although the electrode was originally planned to be positioned inside the scala tympani, only 8 of 13 had full insertion into the scala tympani. Loss of cVEMP response occurred to the same extent in the group with full scala tympani positioning and the group with scala vestibuli involvement. There was a non-significant difference in the loss of caloric response and residual hearing between the two groups. Interscalar dislocation of the electrode inside the cochlea was observed in two patients. A higher loss of residual hearing could be seen in the group with electrode dislocation between the scalae. Our findings indicate that intracochlear electrode dislocation is a possible cause to loss of residual hearing during cochlear implantation but cannot be the sole cause of postoperative vestibular loss.

  2. Radioimmunological analysis of circadian rhythms of cortisol and melatonin in saliva

    International Nuclear Information System (INIS)

    Demel, A.W.

    1990-12-01

    Since blood cortisol (F) and melatonin (MLT) display a circadian secretion pattern and since the saliva concentration of this hormones is an excellent indicator of its blood levels the measurement of salivary F and MLT may be user for examining circadian rhythmicity. In this study the relationship between salivary F and MLT was explored. For this purpose it was necessary first to establish and validate a radioimmunoassay for F in saliva: salivary F was determined by a direct radioimmunoassay using cortisol-3-(O-carb oxymethyl) oximino-(2-( 125 I)iodohistamin) as tracer and cortisol-3-CMO-BSA antiserum. The parallel measurement of F levels in saliva and serum of adults gave an excellent correlation (r=0.87, p 0.00956x ). Serum F was assayed on the Abott TDX-System using a radioimmunofluorescence method. Secondly, using this assay the circadian saliva F pattern was determined as well as the pattern of salivary MLT in 9 young, healthy volunteers. For saliva MLT estimations a previously published method was applied (SCHULZ et al 1990). Using a computerized program (RHYTHM) written by EVE v. CAUTER (1979), the hormone data of each individuum were examined for circadian rhythmicity and its acrophase (time of occurence of the maximum of a sinusoid fitted to the data). The F acrophase occured between 7:00 and 12:00 h (Mean: 3:33 h, SD: 104.4 min). The easy stress-free non invasive nature of saliva collection makes saliva to one of the most accessible body fluids and of high value in studying the circadian system in healthy humans as well as in infants, children, pregnant women and anaemic patients. Measurements of salivary F and MLT may help to elucidate not only the circadian rhythms of these hormones under normal and pathological conditions but it may also provide insight in physiology and pathology of the circadian system in general. (author)

  3. Combination of Light and Melatonin Time Cues for Phase Advancing the Human Circadian Clock

    Science.gov (United States)

    Burke, Tina M.; Markwald, Rachel R.; Chinoy, Evan D.; Snider, Jesse A.; Bessman, Sara C.; Jung, Christopher M.; Wright, Kenneth P.

    2013-01-01

    Study Objectives: Photic and non-photic stimuli have been shown to shift the phase of the human circadian clock. We examined how photic and non-photic time cues may be combined by the human circadian system by assessing the phase advancing effects of one evening dose of exogenous melatonin, alone and in combination with one session of morning bright light exposure. Design: Randomized placebo-controlled double-blind circadian protocol. The effects of four conditions, dim light (∼1.9 lux, ∼0.6 Watts/m2)-placebo, dim light-melatonin (5 mg), bright light (∼3000 lux, ∼7 Watts/m2)-placebo, and bright light-melatonin on circadian phase was assessed by the change in the salivary dim light melatonin onset (DLMO) prior to and following treatment under constant routine conditions. Melatonin or placebo was administered 5.75 h prior to habitual bedtime and 3 h of bright light exposure started 1 h prior to habitual wake time. Setting: Sleep and chronobiology laboratory environment free of time cues. Participants: Thirty-six healthy participants (18 females) aged 22 ± 4 y (mean ± SD). Results: Morning bright light combined with early evening exogenous melatonin induced a greater phase advance of the DLMO than either treatment alone. Bright light alone and melatonin alone induced similar phase advances. Conclusion: Information from light and melatonin appear to be combined by the human circadian clock. The ability to combine circadian time cues has important implications for understanding fundamental physiological principles of the human circadian timing system. Knowledge of such principles is important for designing effective countermeasures for phase-shifting the human circadian clock to adapt to jet lag, shift work, and for designing effective treatments for circadian sleep-wakefulness disorders. Citation: Burke TM; Markwald RR; Chinoy ED; Snider JA; Bessman SC; Jung CM; Wright Jr KP. Combination of light and melatonin time cues for phase advancing the human circadian

  4. A new VLSI complex integer multiplier which uses a quadratic-polynomial residue system with Fermat numbers

    Science.gov (United States)

    Shyu, H. C.; Reed, I. S.; Truong, T. K.; Hsu, I. S.; Chang, J. J.

    1987-01-01

    A quadratic-polynomial Fermat residue number system (QFNS) has been used to compute complex integer multiplications. The advantage of such a QFNS is that a complex integer multiplication requires only two integer multiplications. In this article, a new type Fermat number multiplier is developed which eliminates the initialization condition of the previous method. It is shown that the new complex multiplier can be implemented on a single VLSI chip. Such a chip is designed and fabricated in CMOS-Pw technology.

  5. Role of Hot Water System Design on Factors Influential to Pathogen Regrowth: Temperature, Chlorine Residual, Hydrogen Evolution, and Sediment

    OpenAIRE

    Brazeau, Randi H.; Edwards, Marc A.

    2013-01-01

    Residential water heating is linked to growth of pathogens in premise plumbing, which is the primary source of waterborne disease in the United States. Temperature and disinfectant residual are critical factors controlling increased concentration of pathogens, but understanding of how each factor varies in different water heater configurations is lacking. A direct comparative study of electric water heater systems was conducted to evaluate temporal variations in temperature and water quality ...

  6. Targeting the Circadian Clock to Treat Cancer

    Science.gov (United States)

    Two compounds that target components of the circadian clock killed several types of cancer cells in the lab and slowed the growth of brain cancer in mice without harming healthy cells, as this Cancer Currents post reports.

  7. Cell-permeable Circadian Clock Proteins

    National Research Council Canada - National Science Library

    Johnson, Carl

    2002-01-01

    .... These 'biological clocks' are important to human physiology. For example, psychiatric and medical studies have shown that circadian rhythmicity is involved in some forms of depressive illness, 'jet lag', drug tolerance/efficacy, memory, and insomnia...

  8. Circadian Rhythms, Sleep, and Disorders of Aging.

    Science.gov (United States)

    Mattis, Joanna; Sehgal, Amita

    2016-04-01

    Sleep-wake cycles are known to be disrupted in people with neurodegenerative disorders. These findings are now supported by data from animal models for some of these disorders, raising the question of whether the disrupted sleep/circadian regulation contributes to the loss of neural function. As circadian rhythms and sleep consolidation also break down with normal aging, changes in these may be part of what makes aging a risk factor for disorders like Alzheimer's disease (AD). Mechanisms underlying the connection between circadian/sleep dysregulation and neurodegeneration remain unclear, but several recent studies provide interesting possibilities. While mechanistic analysis is under way, it is worth considering treatment of circadian/sleep disruption as a means to alleviate symptoms of neurodegenerative disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Mathematical Modeling of Circadian/Performance Countermeasures

    Data.gov (United States)

    National Aeronautics and Space Administration — We developed and refined our current mathematical model of circadian rhythms to incorporate melatonin as a marker rhythm. We used an existing physiologically based...

  10. Molecular components of the mammalian circadian clock

    OpenAIRE

    Buhr, Ethan D.; Takahashi, Joseph S.

    2013-01-01

    Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. This is achieved by ocular photoreception relaying signals to the suprachiasmatic nucleus (SCN) in the hypothalamus. Signals from the SCN cause the synchronization of independent circadian clocks throughout the body to appropriate phases. Signals that can entrain these peripheral clocks include humoral signals, metabolic factors, and body temperature. At the level of individual tissu...

  11. The Role of Mammalian Glial Cells in Circadian Rhythm Regulation

    Directory of Open Access Journals (Sweden)

    Donají Chi-Castañeda

    2017-01-01

    Full Text Available Circadian rhythms are biological oscillations with a period of about 24 hours. These rhythms are maintained by an innate genetically determined time-keeping system called the circadian clock. A large number of the proteins involved in the regulation of this clock are transcription factors controlling rhythmic transcription of so-called clock-controlled genes, which participate in a plethora of physiological functions in the organism. In the brain, several areas, besides the suprachiasmatic nucleus, harbor functional clocks characterized by a well-defined time pattern of clock gene expression. This expression rhythm is not restricted to neurons but is also present in glia, suggesting that these cells are involved in circadian rhythmicity. However, only certain glial cells fulfill the criteria to be called glial clocks, namely, to display molecular oscillators based on the canonical clock protein PERIOD, which depends on the suprachiasmatic nucleus for their synchronization. In this contribution, we summarize the current information about activity of the clock genes in glial cells, their potential role as oscillators as well as clinical implications.

  12. An allele of the crm gene blocks cyanobacterial circadian rhythms.

    Science.gov (United States)

    Boyd, Joseph S; Bordowitz, Juliana R; Bree, Anna C; Golden, Susan S

    2013-08-20

    The SasA-RpaA two-component system constitutes a key output pathway of the cyanobacterial Kai circadian oscillator. To date, rhythm of phycobilisome associated (rpaA) is the only gene other than kaiA, kaiB, and kaiC, which encode the oscillator itself, whose mutation causes completely arrhythmic gene expression. Here we report a unique transposon insertion allele in a small ORF located immediately upstream of rpaA in Synechococcus elongatus PCC 7942 termed crm (for circadian rhythmicity modulator), which results in arrhythmic promoter activity but does not affect steady-state levels of RpaA. The crm ORF complements the defect when expressed in trans, but only if it can be translated, suggesting that crm encodes a small protein. The crm1 insertion allele phenotypes are distinct from those of an rpaA null; crm1 mutants are able to grow in a light:dark cycle and have no detectable oscillations of KaiC phosphorylation, whereas low-amplitude KaiC phosphorylation rhythms persist in the absence of RpaA. Levels of phosphorylated RpaA in vivo measured over time are significantly altered compared with WT in the crm1 mutant as well as in the absence of KaiC. Taken together, these results are consistent with the hypothesis that the Crm polypeptide modulates a circadian-specific activity of RpaA.

  13. Internal noise-sustained circadian rhythms in a Drosophila model.

    Science.gov (United States)

    Li, Qianshu; Lang, Xiufeng

    2008-03-15

    Circadian rhythmic processes, mainly regulated by gene expression at the molecular level, have inherent stochasticity. Their robustness or resistance to internal noise has been extensively investigated by most of the previous studies. This work focuses on the constructive roles of internal noise in a reduced Drosophila model, which incorporates negative and positive feedback loops, each with a time delay. It is shown that internal noise sustains reliable oscillations with periods close to 24 h in a region of parameter space, where the deterministic kinetics would evolve to a stable steady state. The amplitudes of noise-sustained oscillations are significantly affected by the variation of internal noise level, and the best performance of the oscillations could be found at an optimal noise intensity, indicating the occurrence of intrinsic coherence resonance. In the oscillatory region of the deterministic model, the coherence of noisy circadian oscillations is suppressed by internal noise, while the period remains nearly constant over a large range of noise intensity, demonstrating robustness of the Drosophila model for circadian rhythms to intrinsic noise. In addition, the effects of time delay in the positive feedback on the oscillations are also investigated. It is found that the time delay could efficiently tune the performance of the noise-sustained oscillations. These results might aid understanding of the exploitation of intracellular noise in biochemical and genetic regulatory systems.

  14. Carbon balance and crop residue management in dynamic equilibrium under a no-till system in Campos Gerais

    Directory of Open Access Journals (Sweden)

    Ademir de Oliveira Ferreira

    2012-11-01

    Full Text Available The adoption of no-tillage systems (NT and the maintenance of crop residues on the soil surface result in the long-term increase of carbon (C in the system, promoting C sequestration and reducing C-CO2 emissions to the atmosphere. The purpose of this study was to evaluate the C sequestration rate and the minimum amount of crop residues required to maintain the dynamic C equilibrium (dC/dt = 0 of two soils (Typic Hapludox with different textural classes. The experiment was arranged in a 2 x 2 x 2 randomized block factorial design. The following factors were analyzed: (a two soil types: Typic Hapludox (Oxisol with medium texture (LVTM and Oxisol with clay texture (LVTA, (b two sampling layers (0-5 and 5-20 cm, and (c two sampling periods (P1 - October 2007; P2 - September 2008. Samples were collected from fields under a long-term (20 years NT system with the following crop rotations: wheat/soybean/black oat + vetch/maize (LVTM and wheat/maize/black oat + vetch/soybean (LVTA. The annual C sequestration rates were 0.83 and 0.76 Mg ha-1 for LVTM and LVTA, respectively. The estimates of the minimum amount of crop residues required to maintain a dynamic equilibrium (dC/dt = 0 were 7.13 and 6.53 Mg ha-1 year-1 for LVTM and LVTA, respectively. The C conversion rate in both studied soils was lower than that reported in other studies in the region, resulting in a greater amount of crop residues left on the soil surface.

  15. Microarray analysis of natural socially regulated plasticity in circadian rhythms of honey bees.

    Science.gov (United States)

    Rodriguez-Zas, Sandra L; Southey, Bruce R; Shemesh, Yair; Rubin, Elad B; Cohen, Mira; Robinson, Gene E; Bloch, Guy

    2012-02-01

    Honey bee workers care for ("nurse") the brood around the clock without circadian rhythmicity, but then they forage outside with strong circadian rhythms and a consolidated nightly rest. This chronobiological plasticity is associated with variation in the expression of the canonical "clock genes" that regulate the circadian clock: nurse bees show no brain rhythms of expression, while foragers do. These results suggest that the circadian system is organized differently in nurses and foragers. Nurses switch to activity with circadian rhythms shortly after being removed from the hive, suggesting that at least some clock cells in their brain continue to measure time while in the hive. We performed a microarray genome-wide survey to determine general patterns of brain gene expression in nurses and foragers sampled around the clock. We found 160 and 541 transcripts that exhibited significant sinusoidal oscillations in nurses and foragers, respectively, with peaks of expression distributed throughout the day in both task groups. Consistent with earlier studies, transcripts of genes involved in circadian rhythms, including Clockwork Orange that has not been studied before in bees, oscillated in foragers but not in nurses. The oscillating transcripts also were enriched for genes involved in the visual system, "development" and "response to stimuli" (foragers), "muscle contraction" and "microfilament motor gene expression" (nurses), and "generation of precursor metabolites" and "energy" (both). Transcripts of genes encoding P450 enzymes oscillated in both nurses and foragers but with a different phase. This study identified new putative clock-controlled genes in the honey bee and suggests that some brain functions show circadian rhythmicity even in nurse bees that are active around the clock.

  16. Microarray Analysis of Natural Socially-Regulated Plasticity in Circadian Rhythms of Honey Bees

    Science.gov (United States)

    Rodriguez-Zas, Sandra L.; Southey, Bruce R.; Shemesh, Yair; Rubin, Elad B.; Cohen, Mira; Robinson, Gene E.; Bloch, Guy

    2012-01-01

    Honey bee workers care for ("nurse") the brood around the clock without circadian rhythmicity, but then they forage outside with strong circadian rhythms and a consolidated nightly rest. This chronobiological plasticity is associated with variation in the expression of the canonical “clock genes” that regulate the circadian clock: nurse bees show no brain rhythms of expression, while foragers do. These results suggest that the circadian system is organized differently in nurses and foragers. Nurses switch to activity with circadian rhythms shortly after removed from the hive suggesting that at least some clock cells in their brain continue to measure time while in the hive. We performed a microarray genome-wide survey to determine general patterns of brain gene expression in nurses and foragers sampled around the clock. We found 160 and 541 transcripts that exhibited significant sinusoidal oscillations in nurses and foragers, respectively, with peaks of expression distributed throughout the day in both task groups. Consistent with earlier studies, transcripts of genes involved in circadian rhythms, including Clockwork Orange that has not been studied before in bees, oscillated in foragers but not in nurses. The oscillating transcripts also were enriched for genes involved in the visual system, “development” and “response to stimuli” (foragers), “muscle contraction” and “microfilament motor gene expression” (nurses), and “generation of precursor metabolites” and “energy” (both). Transcripts of genes encoding P450 enzymes oscillated in both nurses and foragers but with a different phase. This study identified new putative clock-controlled genes in the honey bee and suggests that some brain functions show circadian rhythmicity even in nurse bees that are active around the clock. PMID:22306970

  17. The effects of hydrogen peroxide on the circadian rhythms of Microcystis aeruginosa.

    Directory of Open Access Journals (Sweden)

    Haifeng Qian

    Full Text Available BACKGROUND: The cyanobacterium Microcystis aeruginosa is one of the principal bloom-forming cyanobacteria present in a wide range of freshwater ecosystems. M. aeruginosa produces cyanotoxins, which can harm human and animal health. Many metabolic pathways in M. aeruginosa, including photosynthesis and microcystin synthesis, are controlled by its circadian rhythms. However, whether xenobiotics affect the cyanobacterial circadian system and change its growth, physiology and biochemistry is unknown. We used real-time PCR to study the effect of hydrogen peroxide (H(2O(2 on the expression of clock genes and some circadian genes in M. aeruginosa during the light/dark (LD cycle. RESULTS: The results revealed that H(2O(2 changes the expression patterns of clock genes (kaiA, kaiB, kaiC and sasA and significantly decreases the transcript levels of kaiB, kaiC and sasA. H(2O(2 treatment also decreased the transcription of circadian genes, such as photosynthesis-related genes (psaB, psbD1 and rbcL and microcystin-related genes (mcyA, mcyD and mcyH, and changed their circadian expression patterns. Moreover, the physiological functions of M. aeruginosa, including its growth and microcystin synthesis, were greatly influenced by H(2O(2 treatment during LD. These results indicate that changes in the cyanobacterial circadian system can affect its physiological and metabolic pathways. CONCLUSION: Our findings show that a xenobiotic can change the circadian expression patterns of its clock genes to influence clock-controlled gene regulation, and these influences are evident at the level of cellular physiology.

  18. Atypical expression of circadian clock genes in denervated mouse skeletal muscle.

    Science.gov (United States)

    Nakao, Reiko; Yamamoto, Saori; Horikawa, Kazumasa; Yasumoto, Yuki; Nikawa, Takeshi; Mukai, Chiaki; Oishi, Katsutaka

    2015-05-01

    The central circadian clock in the suprachiasmatic nucleus of the hypothalamus synchronizes peripheral clocks through neural and humoral signals in most mammalian tissues. Here, we analyzed the effects of unilateral sciatic denervation on the expression of circadian clock- and clock-controlled genes in the gastrocnemius muscles of mice twice per day on days 0, 3, 7, 9, 11 and 14 after denervation and six times on each of days 7 and 28 after denervation to assess the regulation mechanism of the circadian clock in skeletal muscle. Sciatic denervation did not affect systemic circadian rhythms since core body temperature (Day 7), corticosterone secretion (Days 7 and 28), and hepatic clock gene expression remained intact (Days 7 and 28). Expression levels of most circadian clock-related genes such as Arntl, Per1, Rora, Nr1d1 and Dbp were reduced in accordance with the extent of muscle atrophy, although circadian Per2 expression was significantly augmented (Day 28). Cosinor analysis revealed that the circadian expression of Arntl (Days 7 and 28) and Dbp (Day 28) was phase advanced in denervated muscle. The mRNA expression of Clock was significantly increased in denervated muscle on Day 3 when the severe atrophy was absent, and it was not affected by atrophic progression for 28 days. Sciatic denervation did not affect the expression of these genes in the contralateral muscle (Days 7 and 28), suggesting that humoral changes were not involved in denervation-induced muscle clock disruption. We then analyzed genome-wide gene expression using microarrays to determine the effects of disrupting the molecular clock in muscle on circadian rhythms at Day 7. Among 478 circadian genes, 313 lost rhythmicity in the denervated muscles. These denervation-sensitive genes included the lipid metabolism-related genes, Nrip1, Bbs1, Ptgis, Acot1, Scd2, Hpgd, Insig1, Dhcr24, Ldlr and Mboat1. Our findings revealed that sciatic denervation disrupts the circadian expression of clock and clock

  19. A class of circadian long non-coding RNAs mark enhancers modulating long-range circadian gene regulation.

    Science.gov (United States)

    Fan, Zenghua; Zhao, Meng; Joshi, Parth D; Li, Ping; Zhang, Yan; Guo, Weimin; Xu, Yichi; Wang, Haifang; Zhao, Zhihu; Yan, Jun

    2017-06-02

    Circadian rhythm exerts its influence on animal physiology and behavior by regulating gene expression at various levels. Here we systematically explored circadian long non-coding RNAs (lncRNAs) in mouse liver and examined their circadian regulation. We found that a significant proportion of circadian lncRNAs are expressed at enhancer regions, mostly bound by two key circadian transcription factors, BMAL1 and REV-ERBα. These circadian lncRNAs showed similar circadian phases with their nearby genes. The extent of their nuclear localization is higher than protein coding genes but less than enhancer RNAs. The association between enhancer and circadian lncRNAs is also observed in tissues other than liver. Comparative analysis between mouse and rat circadian liver transcriptomes showed that circadian transcription at lncRNA loci tends to be conserved despite of low sequence conservation of lncRNAs. One such circadian lncRNA termed lnc-Crot led us to identify a super-enhancer region interacting with a cluster of genes involved in circadian regulation of metabolism through long-range interactions. Further experiments showed that lnc-Crot locus has enhancer function independent of lnc-Crot's transcription. Our results suggest that the enhancer-associated circadian lncRNAs mark the genomic loci modulating long-range circadian gene regulation and shed new lights on the evolutionary origin of lncRNAs. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. Ambulatory assessment of human circadian phase and related sleep disorders from heart rate variability and other non-invasive physiological measurements

    NARCIS (Netherlands)

    Gil Ponce, Enrique

    2017-01-01

    The circadian system plays a key role in our well-being and its effects can be seen in many aspects of our lives. Our master circadian clock, located deep in our brain, influences various physiological processes such as heart rate, body temperature, energy metabolism, hormones, and sleep, to name a

  1. Evaluation of an Anaerobic Digestion System for Processing CELSS Crop Residues for Resource Recovery

    Science.gov (United States)

    Strayer, R. F.; Finger, B. W.; Alazraki, M. P.

    1997-01-01

    Three bioreactors, connected in series, were used to process CELSS potato residues for recovery of resources. The first stage was an anaerobic digestor (8 L working volume; cow rumen contents inoculum; fed-batch; 8 day retention time; feed rate 25 gdw/day) that converted 33% of feed (dry weight loss) to CO2 and "volatile fatty acids" (vfa, 83:8:8 mmolar ratio acetic:propionic:butyric). High nitrate-N in the potato residue feed was absent in the anaerobic effluent, with a high portion converted to NH4(+)-N and the remainder unaccounted and probably lost to denitrification and NH4(+) volatilization. Liquid anaerobic effluent was fed to an aerobic, yeast biomass production vessel (2 L volume; Candida ingens inoculum; batch [pellicle] growth; 2 day retention time) where the VFAs and some NH4(+)-N were converted into yeast biomass. Yeast yields accounted for up to 8% of potato residue fed into the anaerobic bioreactor. The third bioreactor (0.5 L liquid working volume; commercial nitrifier inoculum; packed-bed biofilm; continuous yeast effluent feed; recirculating; constant volume; 2 day hydraulic retention time) was used to convert successfully the remaining NH4(+)-N into nitrate-N (preferred form of N for CELSS crop production) and to remove the remaining degradable soluble organic carbon. Effluents from the last two stages were used for partial replenishment of minerals for hydroponic potato production.

  2. Social memory in the rat: circadian variation and effect of circadian rhythm disruption

    NARCIS (Netherlands)

    Reijmers, L.G.J.E.; Leus, I.E.; Burbach, J.P.H.; Spruijt, B.M.; Ree, van J.M.

    2001-01-01

    Disruption of circadian rhythm can impair long-term passive avoidance memory of rats and mice. The present study investigated whether disruption of circadian rhythm can also impair social memory of male rats. Social memory was assessed using the social discrimination test, in which a short-term

  3. CREBH Maintains Circadian Glucose Homeostasis by Regulating Hepatic Glycogenolysis and Gluconeogenesis.

    Science.gov (United States)

    Kim, Hyunbae; Zheng, Ze; Walker, Paul D; Kapatos, Gregory; Zhang, Kezhong

    2017-07-15

    Cyclic AMP-responsive element binding protein, hepatocyte specific (CREBH), is a liver-enriched, endoplasmic reticulum-tethered transcription factor known to regulate the hepatic acute-phase response and lipid homeostasis. In this study, we demonstrate that CREBH functions as a circadian transcriptional regulator that plays major roles in maintaining glucose homeostasis. The proteolytic cleavage and posttranslational acetylation modification of CREBH are regulated by the circadian clock. Functionally, CREBH is required in order to maintain circadian homeostasis of hepatic glycogen storage and blood glucose levels. CREBH regulates the rhythmic expression of the genes encoding the rate-limiting enzymes for glycogenolysis and gluconeogenesis, including liver glycogen phosphorylase (PYGL), phosphoenolpyruvate carboxykinase 1 (PCK1), and the glucose-6-phosphatase catalytic subunit (G6PC). CREBH interacts with peroxisome proliferator-activated receptor α (PPARα) to synergize its transcriptional activities in hepatic gluconeogenesis. The acetylation of CREBH at lysine residue 294 controls CREBH-PPARα interaction and synergy in regulating hepatic glucose metabolism in mice. CREBH deficiency leads to reduced blood glucose levels but increases hepatic glycogen levels during the daytime or upon fasting. In summary, our studies revealed that CREBH functions as a key metabolic regulator that controls glucose homeostasis across the circadian cycle or under metabolic stress. Copyright © 2017 American Society for Microbiology.

  4. Effect of Residual Stresses and Prediction of Possible Failure Mechanisms on Thermal Barrier Coating System by Finite Element Method

    Science.gov (United States)

    Ranjbar-Far, M.; Absi, J.; Mariaux, G.; Shahidi, S.

    2010-09-01

    This work is focused on the effect of the residual stresses resulting from the coating process and thermal cycling on the failure mechanisms within the thermal barrier coating (TBC) system. To reach this objective, we studied the effect of the substrate preheating and cooling rate on the coating process conditions. A new thermomechanical finite element model (FEM) considering a nonhomogeneous temperature distribution has been developed. In the results, we observed a critical stress corresponding to a low substrate temperature and high cooling rate during spraying of the top-coat material. Moreover, the analysis of the stress distribution after service shows that more critical stresses are obtained in the case where residual stresses are taken into account.

  5. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  6. Analysis of plastic residues in maple sap and syrup collected from tubing systems sanitized with isopropyl alcohol.

    Science.gov (United States)

    Lagacé, Luc; Charron, Carmen; Sadiki, Mustapha

    2017-05-01

    A plastic tubing system operated under vacuum is usually used to collect sap from maple trees during spring time to produce maple syrup. This system is commonly sanitized with isopropyl alcohol (IPA) to remove microbial contamination colonizing the system during the sugar season. Questions have been raised whether IPA would contribute to the leaching of plastic residues in maple sap and syrup coming from sanitized systems. First, an extraction experiment was performed in the lab on commercial plastic tubing materials that were submitted to IPA under harsh conditions. The results of the GC-MS analysis revealed the presence of many compounds that served has target for further tests. Secondly, tests were done on early and mid-season maple sap and syrup coming from many sugarbushes using IPA or not to determine potential concentrations of plastic residues. Results obtained from sap and syrup samples showed that no quantifiable (syrup and reinforced the need to thoroughly rinse the tubing system at the beginning of the season for both sanitized and non sanitized systems.

  7. Acute myocardial infarction and infarct size: do circadian variations play a role?

    Directory of Open Access Journals (Sweden)

    Ibáñez B

    2012-08-01

    Full Text Available Aída Suárez-Barrientos,1 Borja Ibáñez1,21Cardiovascular Institute, Hospital Clínico San Carlos, 2Centro Nacional de Investigaciones Cardiovasculares, Madrid, SpainAbstract: The circadian rhythm influences cardiovascular system physiology, inducing diurnal variations in blood pressure, heart rate, cardiac output, endothelial functions, platelet aggregation, and coronary arterial flow, among other physiological parameters. Indeed, an internal circadian network modulates cardiovascular physiology by regulating heart rate, metabolism, and even myocyte growth and repair ability. Consequently, cardiovascular pathology is also controlled by circadian oscillations, with increased morning incidence of cardiovascular events. The potential circadian influence on the human tolerance to ischemia/reperfusion has not been systematically scrutinized until recently. It has since been proven, in both animals and humans, that infarct size varies during the day depending on the symptom onset time, while circadian fluctuations in spontaneous cardioprotection in humans with ST-segment elevation myocardial infarction (STEMI have also been demonstrated. Furthermore, several studies have proposed that the time of day at which revascularization occurs in patients with STEMI may also influence infarct size and reperfusion outcomes. The potential association of the circadian clock with infarct size advocates the acknowledgment of time of day as a new prognostic factor in patients suffering acute myocardial infarction, which would open up a new field for chronotherapeutic targets and lead to the inclusion of time of day as a variable in clinical trials that test novel cardioprotective strategies.Keywords: cardioprotection, circadian rhythm, reperfusion injury, ST-segment elevation myocardial infarction

  8. Altered expression of circadian clock genes in polyglandular autoimmune syndrome type III.

    Science.gov (United States)

    Angelousi, Anna; Nasiri-Ansari, Narjes; Spilioti, Eliana; Mantzou, Emilia; Kalotyxou, Vasiliki; Chrousos, George; Kaltsas, Gregory; Kassi, Eva

    2018-01-01

    Circadian timing system is a highly conserved, ubiquitous molecular "clock" which creates internal circadian rhythmicity. Dysregulation of clock genes expression is associated with various diseases including immune dysregulation. In this study we investigated the circadian pattern of Clock-related genes in patients with polyglandular autoimmune syndrome type III (PAS type III). Nineteen patients diagnosed with PAS type III and 12 healthy controls were enrolled. mRNA and protein expression of Clock-related genes (CLOCK, BMAL1, ROR and Per-1,-2,-3), as well as the GR-a and the GILZ genes were determined by real-time quantitative PCR and western blot analysis from blood samples drawn at 8 pm and 8am. Serum cortisol and TSH, as well as plasma ACTH, were measured by chemiluminescence. There were no statistical significant differences in the metabolic profile, cortisol, ACTH and TSH levels between patients and controls. Patients with PAS type III expressed higher transcript levels of CLOCK, BMAL1 and Per-1 in the evening than in the morning (p = 0.03, p = 0.029, p = 0.013, respectively), while the ratios (R pm/am ) of GR-a, CLOCK, BMAL1, and Per-3 mRNA levels were statistically different between patients and controls. Cortisol circadian variation (F pm/am ) was positively correlated with GILZ mRNA circadian pattern (R pm/am ) in the patient group and with the GR-a mRNA (R pm/am ) in the control group. Our findings suggest that there is an aberrant circadian rhythm of Clock-related genes in patients with PAS type III. The disruption of the expression of 4 circadian Clock-related genes could indicate a possible association with the pathogenesis of the disease.

  9. Evidence for widespread dysregulation of circadian clock progression in human cancer.

    Science.gov (United States)

    Shilts, Jarrod; Chen, Guanhua; Hughey, Jacob J

    2018-01-01

    The ubiquitous daily rhythms in mammalian physiology are guided by progression of the circadian clock. In mice, systemic disruption of the clock can promote tumor growth. In vitro , multiple oncogenes can disrupt the clock. However, due to the difficulties of studying circadian rhythms in solid tissues in humans, whether the clock is disrupted within human tumors has remained unknown. We sought to determine the state of the circadian clock in human cancer using publicly available transcriptome data. We developed a method, called the clock correlation distance (CCD), to infer circadian clock progression in a group of samples based on the co-expression of 12 clock genes. Our method can be applied to modestly sized datasets in which samples are not labeled with time of day and coverage of the circadian cycle is incomplete. We used the method to define a signature of clock gene co-expression in healthy mouse organs, then validated the signature in healthy human tissues. By then comparing human tumor and non-tumor samples from twenty datasets of a range of cancer types, we discovered that clock gene co-expression in tumors is consistently perturbed. Subsequent analysis of data from clock gene knockouts in mice suggested that perturbed clock gene co-expression in human cancer is not caused solely by the inactivation of clock genes. Furthermore, focusing on lung cancer, we found that human lung tumors showed systematic changes in expression in a large set of genes previously inferred to be rhythmic in healthy lung. Our findings suggest that clock progression is dysregulated in many solid human cancers and that this dysregulation could have broad effects on circadian physiology within tumors. In addition, our approach opens the door to using publicly available data to infer circadian clock progression in a multitude of human phenotypes.

  10. The circadian clock in skin: implications for adult stem cells, tissue regeneration, cancer, aging, and immunity

    Science.gov (United States)

    Plikus, Maksim V.; Van Spyk, Elyse Noelani; Pham, Kim; Geyfman, Mikhail; Kumar, Vivek; Takahashi, Joseph S.; Andersen, Bogi

    2015-01-01

    Historically work on peripheral circadian clocks has been focused on organs and tissues that have prominent metabolic functions, such as liver, fat and muscle. In recent years, skin is emerging as a model for studying circadian clock regulation of cell proliferation, stem cell functions, tissue regeneration, aging and carcinogenesis. Morphologically skin is complex, containing multiple cell types and structures, and there is evidence for a functional circadian clock in most, if not all, of its cell types. Despite the complexity, skin stem cell populations are well defined, experimentally tractable and exhibit prominent daily cell proliferation cycles. Hair follicle stem cells also participate in recurrent, long-lasting cycles of regeneration -- the hair growth cycles. Among other advantages of skin is a broad repertoire of available genetic tools enabling the creation of cell-type specific circadian mutants. Also, due to the accessibility of the skin, in vivo imaging techniques can be readily applied to study the circadian clock and its outputs in real time, even at the single-cell level. Skin provides the first line of defense against many environmental and stress factors that exhibit dramatic diurnal variations such as solar UV radiation and temperature. Studies have already linked the circadian clock to the control of UVB-induced DNA damage and skin cancers. Due to the important role that skin plays in the defense against microorganisms, it represents a promising model system to further explore the role of the clock in the regulation of the body's immune functions. To that end, recent studies have already linked the circadian clock to psoriasis, one of the most common immune-mediated skin disorders. The skin also provides opportunities to interrogate clock regulation of tissue metabolism in the context of stem cells and regeneration. Furthermore, many animal species feature prominent seasonal hair molt cycles, offering an attractive model for investigating the

  11. The Relative Impact of Sleep and Circadian Drive on Motor Skill Acquisition and Memory Consolidation.

    Science.gov (United States)

    Tucker, Matthew A; Morris, Christopher J; Morgan, Alexandra; Yang, Jessica; Myers, Samantha; Pierce, Joanna Garcia; Stickgold, Robert; Scheer, Frank A J L

    2017-04-01

    Sleep during the biological night facilitates memory consolidation. Here we determined the impact of sleep and wake on motor skill learning (acquisition) and subsequent off-line skill improvement (memory consolidation), independent of circadian phase, and compared this to the impact of the endogenous circadian system, independent of whether sleep occurred during the biological night or day. Participants completed two 8-day sleep laboratory visits, adhering on one visit to a circadian aligned ("normal") sleep schedule for the full duration of the protocol, and on the other to a circadian misaligned (12-hour inverted) schedule, with alignment during the first 3 days, a 12-hour 'slam shift' on Day 4, followed by circadian misalignment during the last 4 days of the protocol. Participants were repeatedly trained and tested on different versions of the finger-tapping motor sequence task across each visit. Sleep facilitated offline memory consolidation regardless of whether it occurred during the biological day or night, while circadian phase had no significant impact. These sleep-related benefits remained after accounting for general motor speed, measured in the absence of learning. In addition, motor skill acquisition was facilitated when the training session followed shortly after sleep, without significant impact of circadian phase (biological morning vs. evening). This effect was largely driven by heightened acquisition in participants who slept during the day and were trained shortly thereafter, that is, when acquisition occurred during the biological evening. These benefits were also retained after controlling for general motor speed. Sleep benefits both the acquisition and consolidation of motor skill regardless of whether they occur during the biological day or night. After controlling for general motor speed, a critical adjustment that few studies perform, these sleep benefits remain intact. Our findings have clear implications for night shift workers who obtain

  12. Circadian and dark-pulse activation of orexin/hypocretin neurons

    Directory of Open Access Journals (Sweden)

    Marston Oliver J

    2008-12-01

    Full Text Available Temporal control of brain and behavioral states emerges as a consequence of the interaction between circadian and homeostatic neural circuits. This interaction permits the daily rhythm of sleep and wake, regulated in parallel by circadian cues originating from the suprachiasmatic nuclei (SCN and arousal-promoting signals arising from the orexin-containing neurons in the tuberal hypothalamus (TH. Intriguingly, the SCN circadian clock can be reset by arousal-promoting stimuli while activation of orexin/hypocretin neurons is believed to be under circadian control, suggesting the existence of a reciprocal relationship. Unfortunately, since orexin neurons are themselves activated by locomotor promoting cues, it is unclear how these two systems interact to regulate behavioral rhythms. Here mice were placed in conditions of constant light, which suppressed locomotor activity, but also revealed a highly pronounced circadian pattern in orexin neuronal activation. Significantly, activation of orexin neurons in the medial and lateral TH occurred prior to the onset of sustained wheel-running activity. Moreover, exposure to a 6 h dark pulse during the subjective day, a stimulus that promotes arousal and phase advances behavioral rhythms, activated neurons in the medial and lateral TH including those containing orexin. Concurrently, this stimulus suppressed SCN activity while activating cells in the median raphe. In contrast, dark pulse exposure during the subjective night did not reset SCN-controlled behavioral rhythms and caused a transient suppression of neuronal activation in the TH. Collectively these results demonstrate, for the first time, pronounced circadian control of orexin neuron activation and implicate recruitment of orexin cells in dark pulse resetting of the SCN circadian clock.

  13. Research on the optimal dynamical systems of three-dimensional Navier-Stokes equations based on weighted residual

    Science.gov (United States)

    Peng, NaiFu; Guan, Hui; Wu, ChuiJie

    2016-04-01

    In this paper, the theory of constructing optimal dynamical systems based on weighted residual presented by Wu & Sha is applied to three-dimensional Navier-Stokes equations, and the optimal dynamical system modeling equations are derived. Then the multiscale global optimization method based on coarse graining analysis is presented, by which a set of approximate global optimal bases is directly obtained from Navier-Stokes equations and the construction of optimal dynamical systems is realized. The optimal bases show good properties, such as showing the physical properties of complex flows and the turbulent vortex structures, being intrinsic to real physical problem and dynamical systems, and having scaling symmetry in mathematics, etc.. In conclusion, using fewer terms of optimal bases will approach the exact solutions of Navier-Stokes equations, and the dynamical systems based on them show the most optimal behavior.

  14. Novel in vitro systems for prediction of veterinary drug residues in ovine milk and dairy products.

    Science.gov (United States)

    González-Lobato, L; Real, R; Herrero, D; de la Fuente, A; Prieto, J G; Marqués, M M; Alvarez, A I; Merino, G

    2014-01-01

    A new in vitro tool was developed for the identification of veterinary substrates of the main drug transporter in the mammary gland. These drugs have a much higher chance of being concentrated into ovine milk and thus should be detectable in dairy products. Complementarily, a cell model for the identification of compounds that can inhibit the secretion of drugs into ovine milk, and thus reduce milk residues, was also generated. The ATP-binding cassette transporter G2 (ABCG2) is responsible for the concentration of its substrates into milk. The need to predict potential drug residues in ruminant milk has prompted the development of in vitro cell models over-expressing ABCG2 for these species to detect veterinary drugs that interact with this transporter. Using these models, several substrates for bovine and caprine ABCG2 have been found, and differences in activity between species have been reported. However, despite being of great toxicological relevance, no suitable in vitro model to predict substrates of ovine ABCG2 was available. New MDCKII and MEF3.8 cell models over-expressing ovine ABCG2 were generated for the identification of substrates and inhibitors of ovine ABCG2. Five widely used veterinary antibiotics (marbofloxacin, orbifloxacin, sarafloxacin, danofloxacin and difloxacin) were discovered as new substrates of ovine ABCG2. These results were confirmed for the bovine transporter and its Y581S variant using previously generated cell models. In addition, the avermectin doramectin was described as a new inhibitor of ruminant ABCG2. This new rapid assay to identify veterinary drugs that can be concentrated into ovine milk will potentially improve detection and monitoring of veterinary drug residues in ovine milk and dairy products.

  15. Development of gasification and melting system for energy recovery from automobile shredder residue

    International Nuclear Information System (INIS)

    Jung, Hae Young; Seo, Yong Chil; Cho, Sung Jin; Lee, Jang Su; Lee, Ki Bae; Jeong, Dae Woon; Kim, Woo Hyun; Roh, Seon Ah; Min, Tai Jin

    2010-01-01

    As one of the efforts to increase recycling rate of end of life vehicles enforcing by the governmental regulation, automobile shredder residue (ASR) was considered to treat by a thermal method with converting waste to energy. Gasification and melting experimental processes of lab (1 kg/ hour) and pilot (5 ton/ day) scale were installed. ASR collected from a domestic shredding company was experimented at a lab-scale and pilot-scale gasification and melting process which is similar to the shaft type gasification melting furnace. The characteristics of syngas, tar and residue (slag) generated from a conversion process (gasification and melting) were analyzed to provide the information to further utilize them as fuel and recyclable materials in scaled up plants. A series of experiments have been conducted with various air equivalent ratios (ERs), and syngas compositions, carbon conversion efficiency, heating value of syngas, yield and characteristics of slag were analyzed. Finally, slags generated from the process were recycled with various alternative technologies. In summary, energy conversion technology of ASR with the least production of residue by gasification and slag utilization has been developed. The main components in product gas were H 2 , CO, CH 4 and CO 2 ; and concentrations of C 2 H 4 and C 2 H 6 were less. This can be used as clean fuel gas whose heating value ranged from 2.5 to 14.0 MJ/ m 3 . Most of slag generated from the process can further be fabricated to valuable and usable products. Such combined technology would result in achieving almost zero waste release from ELVs. (author)

  16. Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus) Residues.

    Science.gov (United States)

    Zafra-Rojas, Quinatzin Y; Cruz-Cansino, Nelly S; Quintero-Lira, Aurora; Gómez-Aldapa, Carlos A; Alanís-García, Ernesto; Cervantes-Elizarrarás, Alicia; Güemes-Vera, Norma; Ramírez-Moreno, Esther

    2016-07-21

    Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus) residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X₁: 80%-90%) and extraction time (X₂: 10-15 min), and results were compared with conventional extraction methods. The optimal conditions for antioxidants extraction were 91% amplitude for 15 min. The results for total phenolic content and anthocyanins and antioxidant activity by ABTS and DPPH were of 1201.23 mg gallic acid equivalent (GAE)/100 g dry weight basis (dw); 379.12 mg/100 g·dw; 6318.98 µmol Trolox equivalent (TE)/100 g·dw and 9617.22 µmol TE/100 g·dw, respectively. Compared to solvent extraction methods (water and ethanol), ultrasound achieved higher extraction of all compounds except for anthocyanins. The results obtained demonstrated that ultrasound is an alternative to improve extraction yield of antioxidants from fruit residues such as blackberry.

  17. Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus Residues

    Directory of Open Access Journals (Sweden)

    Quinatzin Y. Zafra-Rojas

    2016-07-01

    Full Text Available Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X1: 80%–90% and extraction time (X2: 10–15 min, and results were compared with conventional extraction methods. The optimal conditions for antioxidants extraction were 91% amplitude for 15 min. The results for total phenolic content and anthocyanins and antioxidant activity by ABTS and DPPH were of 1201.23 mg gallic acid equivalent (GAE/100 g dry weight basis (dw; 379.12 mg/100 g·dw; 6318.98 µmol Trolox equivalent (TE/100 g·dw and 9617.22 µmol TE/100 g·dw, respectively. Compared to solvent extraction methods (water and ethanol, ultrasound achieved higher extraction of all compounds except for anthocyanins. The results obtained demonstrated that ultrasound is an alternative to improve extraction yield of antioxidants from fruit residues such as blackberry.

  18. Crop residue management in arable cropping systems under a temperate climate. Part 2: Soil physical properties and crop production. A review

    Directory of Open Access Journals (Sweden)

    Hiel, MP.

    2016-01-01

    Full Text Available Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production. Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield. Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts.

  19. Hydrothermal carbonization of biomass residues: mass spectrometric characterization for ecological effects in the soil-plant system.

    Science.gov (United States)

    Jandl, Gerald; Eckhardt, Kai-Uwe; Bargmann, Inge; Kücke, Martin; Greef, Jörg-Michael; Knicker, Heike; Leinweber, Peter

    2013-01-01

    Hydrochars, technically manufactured by hydrothermal carbonization (HTC) of biomass residues, are recently tested in high numbers for their suitability as feedstock for bioenergy production, the bioproduct industry, and as long-term carbon storage in soil, but ecological effects in the soil-plant system are not sufficiently known. Therefore, we investigated the influence of different biomass residues and process duration on the molecular composition of hydrochars, and how hydrochar addition to soils affected the germination of spring barley ( L.) seeds. Samples from biomass residues and the corresponding hydrochars were analyzed by pyrolysis-field ionization mass spectrometry (Py-FIMS) and gaseous emissions from the germination experiments with different soil-hydrochar mixtures by gas chromatography/mass spectrometry (GC/MS). The molecular-level characterization of various hydrochars by Py-FIMS clearly showed that the kind of biomass residue influenced the chemical composition of the corresponding hydrochars more strongly than the process duration. In addition to various detected possible toxic substances, two independent mass spectrometric methods (Py-FIMS and GC/MS) indicated long C-chain aliphatic compounds which are typically degraded to the C-unit ethylene that can evoke phytotoxic effects in high concentrations. This showed for the first time possible chemical compounds to explain toxic effects of hydrochars on plant growth. It is concluded that the HTC process did not result in a consistent product with defined chemical composition. Furthermore, possible toxic effects urgently need to be investigated for each individual hydrochar to assess effects on the soil organic matter composition and the soil biota before hydrochar applications as an amendment on agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  20. Does circadian disruption play a role in the metabolic-hormonal link to delayed lactogenesis II?

    Directory of Open Access Journals (Sweden)

    Manjie eFu

    2015-02-01

    Full Text Available Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for six months, with continued breastfeeding for at least one year. However, in the US, only 18.8% of infants are exclusively breastfed until six months of age. For mothers who initiate breastfeeding, the early postpartum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early postpartum period are more likely to discontinue breastfeeding within two weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (i.e. onset of milk coming in more than 72 h postpartum. Recent studies report a metabolic-hormonal link to delayed lactogenesis II. This is not surprising because around the time of birth the mother’s entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam’s ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet lag, sleep disorders and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize delayed lactogenesis II is related to disruption of the mother’s circadian system. Here we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success.

  1. Does Circadian Disruption Play a Role in the Metabolic-Hormonal Link to Delayed Lactogenesis II?

    Science.gov (United States)

    Fu, Manjie; Zhang, Lingsong; Ahmed, Azza; Plaut, Karen; Haas, David M; Szucs, Kinga; Casey, Theresa M

    2015-01-01

    Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for 6 months, with continued breastfeeding for at least 1 year. However, in the US, only 18.8% of infants are exclusively breastfed until 6 months of age. For mothers who initiate breastfeeding, the early post-partum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early post-partum period are more likely to discontinue breastfeeding within 2 weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (DLII; i.e., onset of milk "coming in" more than 72 h post-partum). Recent studies report a metabolic-hormonal link to DLII. This is not surprising because around the time of birth the mother's entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam's ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet-lag, sleep disorders, and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize that DLII is related to disruption of the mother's circadian system. Here, we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success.

  2. Does Circadian Disruption Play a Role in the Metabolic–Hormonal Link to Delayed Lactogenesis II?

    Science.gov (United States)

    Fu, Manjie; Zhang, Lingsong; Ahmed, Azza; Plaut, Karen; Haas, David M.; Szucs, Kinga; Casey, Theresa M.

    2015-01-01

    Breastfeeding improves maternal and child health. The American Academy of Pediatrics recommends exclusive breastfeeding for 6 months, with continued breastfeeding for at least 1 year. However, in the US, only 18.8% of infants are exclusively breastfed until 6 months of age. For mothers who initiate breastfeeding, the early post-partum period sets the stage for sustained breastfeeding. Mothers who experience breastfeeding problems in the early post-partum period are more likely to discontinue breastfeeding within 2 weeks. A major risk factor for shorter breastfeeding duration is delayed lactogenesis II (DLII; i.e., onset of milk “coming in” more than 72 h post-partum). Recent studies report a metabolic–hormonal link to DLII. This is not surprising because around the time of birth the mother’s entire metabolism changes to direct nutrients to mammary glands. Circadian and metabolic systems are closely linked, and our rodent studies suggest circadian clocks coordinate hormonal and metabolic changes to support lactation. Molecular and environmental disruption of the circadian system decreases a dam’s ability to initiate lactation and negatively impacts milk production. Circadian and metabolic systems evolved to be functional and adaptive when lifestyles and environmental exposures were quite different from modern times. We now have artificial lights, longer work days, and increases in shift work. Disruption in the circadian system due to shift work, jet-lag, sleep disorders, and other modern life style choices are associated with metabolic disorders, obesity, and impaired reproduction. We hypothesize that DLII is related to disruption of the mother’s circadian system. Here, we review literature that supports this hypothesis, and describe interventions that may help to increase breastfeeding success. PMID:25988133

  3. Detection of antibiotic residues in bovine milk by a voltammetric electronic tongue system

    International Nuclear Information System (INIS)

    Wei Zhenbo; Wang Jun

    2011-01-01

    A voltammetric electronic tongue (VE-tongue) was developed to detect antibiotic residues in bovine milk. Six antibiotics (Chloramphenicol, Erythromycin, Kanamycin sulfate, Neomycin sulfate, Streptomycin sulfate and Tetracycline HCl) spiked at four different concentration levels (0.5, 1, 1.5 and 2 maximum residue limits (MRLs)) were classified based on VE-tongue by two pattern recognition methods: principal component analysis (PCA) and discriminant function analysis (DFA). The VE-tongue was composed of five working electrodes (gold, silver, platinum, palladium, and titanium) positioned in a standard three-electrode configuration. The Multi-frequency large amplitude pulse voltammetry (MLAPV) which consisted of four segments (1 Hz, 10 Hz, 100 Hz and 1000 Hz) was applied as potential waveform. The six antibiotics at the MRLs could not be separated from bovine milk completely by PCA, but all the samples were demarcated clearly by DFA. Three regression models: Principal Component Regression Analysis (PCR), Partial Least Squares Regression (PLSR), and Least Squares-Support Vector Machines (LS-SVM) were used for concentrations of antibiotics prediction. All the regression models performed well, and PCR had the most stable results.

  4. Detection of antibiotic residues in bovine milk by a voltammetric electronic tongue system

    Energy Technology Data Exchange (ETDEWEB)

    Wei Zhenbo [Zhejiang University, Department of Bio-Systems Engineering, 268 Kaixuan Road, Hangzhou, Zhejiang 310029 (China); Wang Jun, E-mail: jwang@zju.edu.cn [Zhejiang University, Department of Bio-Systems Engineering, 268 Kaixuan Road, Hangzhou, Zhejiang 310029 (China)

    2011-05-23

    A voltammetric electronic tongue (VE-tongue) was developed to detect antibiotic residues in bovine milk. Six antibiotics (Chloramphenicol, Erythromycin, Kanamycin sulfate, Neomycin sulfate, Streptomycin sulfate and Tetracycline HCl) spiked at four different concentration levels (0.5, 1, 1.5 and 2 maximum residue limits (MRLs)) were classified based on VE-tongue by two pattern recognition methods: principal component analysis (PCA) and discriminant function analysis (DFA). The VE-tongue was composed of five working electrodes (gold, silver, platinum, palladium, and titanium) positioned in a standard three-electrode configuration. The Multi-frequency large amplitude pulse voltammetry (MLAPV) which consisted of four segments (1 Hz, 10 Hz, 100 Hz and 1000 Hz) was applied as potential waveform. The six antibiotics at the MRLs could not be separated from bovine milk completely by PCA, but all the samples were demarcated clearly by DFA. Three regression models: Principal Component Regression Analysis (PCR), Partial Least Squares Regression (PLSR), and Least Squares-Support Vector Machines (LS-SVM) were used for concentrations of antibiotics prediction. All the regression models performed well, and PCR had the most stable results.

  5. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  6. Dynamical mechanism of Bmal 1 / Rev- erbα loop in circadian clock

    Science.gov (United States)

    Li, Ying; Liu, Zengrong

    2015-07-01

    In mammals, the circadian clock is driven by multiple integrated transcriptional feedback loops involving three kinds of central clock-controlled elements (CCEs): E-boxes, D-boxes and ROR-elements. With the aid of CCEs, the concentrations of the active proteins are approximated by the delayed concentrations of mRNAs, which simplifies the circadian system drastically. The regulatory loop composed by BMAL1 and REV-ERB- α plays important roles in circadian clock. With delay differential equations, we gave a mathematical model of this loop and investigated its dynamical mechanisms. Specially, we theoretically provided the sufficient conditions for sustained oscillation of the loop with Hopf bifurcation theory. The total of delays determines the emergence of oscillators, which explains the crucial roles of delays in circadian clock revealed by biological experiments. Numerically, we studied the amplitude and period against the variations of delays and the degradation rates. The different sensitivities of amplitude and period on these factors provide ideas to adjust the amplitude or period of circadian oscillators.

  7. Topological specificity and hierarchical network of the circadian calcium rhythm in the suprachiasmatic nucleus.

    Science.gov (United States)

    Enoki, Ryosuke; Kuroda, Shigeru; Ono, Daisuke; Hasan, Mazahir T; Ueda, Tetsuo; Honma, Sato; Honma, Ken-ichi

    2012-12-26

    The circadian pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) is a hierarchical multioscillator system in which neuronal networks play crucial roles in expressing coherent rhythms in physiology and behavior. However, our understanding of the neuronal network is still incomplete. Intracellular calcium mediates the input signals, such as phase-resetting stimuli, to the core molecular loop involving clock genes for circadian rhythm generation and the output signals from the loop to various cellular functions, including changes in neurotransmitter release. Using a unique large-scale calcium imaging method with genetically encoded calcium sensors, we visualized intracellular calcium from the entire surface of SCN slice in culture including the regions where autonomous clock gene expression was undetectable. We found circadian calcium rhythms at a single-cell level in the SCN, which were topologically specific with a larger amplitude and more delayed phase in the ventral region than the dorsal. The robustness of the rhythm was reduced but persisted even after blocking the neuronal firing with tetrodotoxin (TTX). Notably, TTX dissociated the circadian calcium rhythms between the dorsal and ventral SCN. In contrast, a blocker of gap junctions, carbenoxolone, had only a minor effect on the calcium rhythms at both the single-cell and network levels. These results reveal the topological specificity of the circadian calcium rhythm in the SCN and the presence of coupled regional pacemakers in the dorsal and ventral regions. Neuronal firings are not necessary for the persistence of the calcium rhythms but indispensable for the hierarchical organization of rhythmicity in the SCN.

  8. Dissection of the couplings between cellular messengers and the circadian clock

    International Nuclear Information System (INIS)

    Tong Jian; Edmunds, L.N.

    1995-12-01

    It has been known in recent years that living cells can exhibit circadian rhythms in totally different physiological processes. Intracellular messengers were demonstrated to mediate the entrained pathways linking rhythmic components between circadian clock and its output signalling. Levels of cyclic AMP and cyclic GMP in synchronized cells, and activities of the two key enzymes (AC and PDE) responsible for the cyclic AMP metabolism were measured by applying the isotopic techniques. Bimodal circadian oscillations of the messenger levels and the enzyme activities were disclosed in LD: 12, 12 cycle and constant darkness, as well as in the dividing and non-dividing cultures of the Euglena ZC mutant. Interference experiments with the enzyme activator and inhibitor such as forskolin, 8-Br-cGMP and LY 83583, and analysis of the cell division cycle (CDC) and coupling messengers suggested that the peak pulse of cyclic AMP, circadian oscillation of the AC-cAMP-PDE system and phase-dependent regulation by cyclic GMP might be important coupling factors in downstream mediation between the circadian clock and the CDC. (7 figs.)

  9. Sleep and circadian disruption and incident breast cancer risk: An evidence-based and theoretical review.

    Science.gov (United States)

    Samuelsson, Laura B; Bovbjerg, Dana H; Roecklein, Kathryn A; Hall, Martica H

    2018-01-01

    Opportunities for restorative sleep and optimal sleep-wake schedules are becoming luxuries in industrialized cultures, yet accumulating research has revealed multiple adverse health effects of disruptions in sleep and circadian rhythms, including increased risk of breast cancer. The literature on breast cancer risk has focused largely on adverse effects of night shift work and exposure to light at night (LAN), without considering potential effects of associated sleep disruptions. As it stands, studies on breast cancer risk have not considered the impact of both sleep and circadian disruption, and the possible interaction of the two through bidirectional pathways, on breast cancer risk in the population at large. We review and synthesize this literature, including: 1) studies of circadian disruption and incident breast cancer; 2) evidence for bidirectional interactions between sleep and circadian systems; 3) studies of sleep and incident breast cancer; and 4) potential mechanistic pathways by which interrelated sleep and circadian disruption may contribute to the etiology of breast cancer. Copyright © 2017. Published by Elsevier Ltd.

  10. Simulation of the loss of residual heat removal system of an integral test facility using French computer code CATHARE

    International Nuclear Information System (INIS)

    Troshko, A.A.; Hassan, Y.A.

    1997-01-01

    Thermal hydraulic CATHARE V1.3U code has been used to simulate an International Standard Problem (ISP38) experiment conducted at BETHSY Integral Test Facility located in Grenoble, France. This experiment dealt with simulation of the loss of Residual Heat Removal System (RHRS) during midloop operation. Overall, the code's prediction and experimental data were found to be in a reasonable qualitative agreement. However, the code underestimated the time of the core uncover and the actuation of the gravity feed injection. It was found that the code's model of the upward tee junction needs to be refined for the low pressure ranges

  11. Circadian rhythms in Macaca mulatta monkeys during Bion 11 flight

    Science.gov (United States)

    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.

  12. The circadian clock in cancer development and therapy

    Science.gov (United States)

    Most aspects of mammalian function display circadian rhythms driven by an endogenous clock. The circadian clock is operated by genes and comprises a central clock in the brain that responds to environmental cues and controls subordinate clocks in peripheral tissues via circadian output pathways. The...

  13. Natural selection against a circadian clock gene mutation in mice

    NARCIS (Netherlands)

    Spoelstra, K.; Wikelski, Martin; Daan, Serge; Loudon, Andrew; Hau, Michaela

    2016-01-01

    Circadian rhythms with an endogenous period close or equal to the natural light-dark cycle are considered evolutionarily adaptive (‘circadian resonance hypothesis’). Despite remarkable insight into the molecular mechanisms driving circadian cycles, this hypothesis has not been tested under natural

  14. Natural selection against a circadian clock gene mutation in mice

    NARCIS (Netherlands)

    Spoelstra, Kamiel; Wikelski, Martin; Daan, Serge; Loudon, Andrew S I; Hau, Michaela

    2016-01-01

    Circadian rhythms with an endogenous period close to or equal to the natural light-dark cycle are considered evolutionarily adaptive ("circadian resonance hypothesis"). Despite remarkable insight into the molecular mechanisms driving circadian cycles, this hypothesis has not been tested under

  15. Circadian Variation of Breast Milk Components and Implications for Care.

    Science.gov (United States)

    White, Robert D

    2017-09-01

    Several components of breast milk show circadian variability. It is likely that at least some of these macronutrients, hormones, and micronutrients produce circadian stimuli that enhance the well-being of breast-fed infants. Future research should determine whether high-risk infants benefit if breast milk is given during the same circadian phase as it was expressed.

  16. The regulations and role of circadian clock and melatonin in uterine receptivity and pregnancy-An immunological perspective.

    Science.gov (United States)

    Man, Gene Chi Wai; Zhang, Tao; Chen, Xiaoyan; Wang, Jianzhang; Wu, Fangrong; Liu, Yingyu; Wang, Chi Chiu; Cheong, Ying; Li, Tin Chiu

    2017-08-01

    During normal pregnancy, the mechanism by which the fetus escapes immunological rejection by the maternal womb remains elusive. Given the biological complexities, the immunological mechanism is unlikely to be simply an allograft response in acceptance or rejection of the early pregnancy. Circadian clock responsible for the mammalian circadian rhythm is an endogenously generated rhythm associated with almost all physiological processes including reproduction. There is now growing evidence to suggest that the circadian clocks are intricately linked to the immune system and pregnancy. When perturbed, the role of immune cells can be affected on maintaining the enriched vascular system needed for placentation. This alteration can be triggered by the irregular production of maternal and placental melatonin. Hence, the role of circadian rhythm modulators such as melatonin offers intriguing opportunities for therapy. In this review, we evaluate the complex interaction between the circadian clock and melatonin within the immune system and their roles in the circadian regulation and maintenance of normal pregnancy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. A GC-system for the analysis of residual geothermal gases

    Science.gov (United States)

    Sheppard, D.S.; Truesdell, A.H.

    1985-01-01

    The gases evolved from geothermal fields, after condensation of H2O, CO2, H2S and NH3 in caustic solution, contain He, H2, Ar, O2, N2, CH4 and higher hydrocarbons. The analysis for the major components in these residual gas mixtures can be achieved by use of two simple gas chromatographs in parallel, and using 5A?? molecular sieve. The separation of He and H2 to baseline is achieved by using low temperatures (30??C) coupled with a relatively long column; and the difficult separation of Ar and O2 is achieved by use of a cryogenically cooled column. The use of switching valves to backflush and bypass columns ensures that a minimum time for analysis can be achieved whilst retaining baseline separations of the He/H2 and Ar/O2 pairs. ?? 1985 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.

  18. Channel Model Optimization with Reflection Residual Component for Indoor MIMO-VLC System

    Science.gov (United States)

    Chen, Yong; Li, Tengfei; Liu, Huanlin; Li, Yichao

    2017-12-01

    A fast channel modeling method is studied to solve the problem of reflection channel gain for multiple input multiple output-visible light communications (MIMO-VLC) in the paper. For reducing the computational complexity when associating with the reflection times, no more than 3 reflections are taken into consideration in VLC. We think that higher order reflection link consists of corresponding many times line of sight link and firstly present reflection residual component to characterize higher reflection (more than 2 reflections). We perform computer simulation results for point-to-point channel impulse response, receiving optical power and receiving signal to noise ratio. Based on theoretical analysis and simulation results, the proposed method can effectively reduce the computational complexity of higher order reflection in channel modeling.

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

    Directory of Open Access Journals (Sweden)

    Goldstein-Kral Lauren

    2011-01-01

    WT siblings. Conclusion Our data suggests that circadian rhythms can be initiated and maintained in the absence of SCN and other tissues in the ventral brain. However, the SCN may have a role in regulating the amplitude of rhythms when environmental cues are absent. This provides some of the first evidence that the SCN of teleosts is not essential for establishing circadian rhythms during development. Several SCN-independent circadian rhythms have also been found in mammalian species. Thus, zebrafish may serve as a model system for understanding how vertebrate embryos coordinate rhythms that are controlled by different circadian clocks.

  20. Content Of 2,4-D-14C Herbicide Residue In Water And Soil Of Irrigated Rice Field System

    International Nuclear Information System (INIS)

    Chairul, Sofnie M.; Djabir, Elida; Magdalena, Nelly

    2000-01-01

    The investigation of 2,4-D exp.-14C herbicide residue in water and soil of irrigated rice field system was carried out. Rice plant and weeds (Monochoria vaginalis Burn. F. Presl) were planted in 101 buckets using two kinds of soil condition, I.e. normal soil and 30 % above normal compact soil. After one week planting, the plants were sprayed with 1 u Ci of 2,4-D exp.-14C and 0,4 mg non labeled 2,4-D. The herbicide residue content was determined 0, 2, 4, 8 and 10 weeks after spraying with 2,4-D herbicide. The analysis was done using Combustion Biological Oxidizer merk Harvey ox-400, and counted with Liquid Scintillation Counter merk Beckman model LS-1801. The results indicates that the herbicide contents in water and soil decrease from the first spraying with herbicide until harvest herbicide Residue content in water after harvest was 0.87 x 10 exp.-6 ppm for soil normal condition, and 0.59 x 10 exp.-6 pm for the soil 30 % up normal condition, while herbicide content in soil was 1.54 x 10 exp.-6 ppm for soil normal condition and 1.48 x 10 exp.-6 ppm for soil 30 % up normal. 2,4-D herbicide residue content in rice after harvest was 0.27 x 10 exp.-6 ppm for normal soil condition and 0.25 x 10 exp.-6 ppm for the soil 30 % up normal. 2,4-D herbicide residue content in roots and leaves of weeds after harvest were respectively 0.29 x 10 exp.-6 ppm and 0.18 x 10 exp.-6 for normal soil condition, while for 30 % up normal soil were 0.25 x 10 exp.-5 ppm and 0.63 x 10 exp.-7 ppm. This result indicates that there is no effect pollution to surrounding area, because the herbicide content is still bellow the allowed detection limit, 0.05 ppm

  1. Tillage and residue management effect on soil properties, crop performance and energy relations in greengram (Vigna radiata L. under maize-based cropping systems

    Directory of Open Access Journals (Sweden)

    J.R. Meena

    2015-12-01

    Full Text Available Effect of tillage and crop residue management on soil properties, crop performance, energy relations and economics in greengram (Vigna radiata L. was evaluated under four maize-based cropping systems in an Inceptisol of Delhi, India. Soil bulk density, hydraulic conductivity and aggregation at 0–15 cm layer were significantly affected both by tillage and cropping systems, while zero tillage significantly increased the soil organic carbon content. Yields of greengram were significantly higher in maize–chickpea and maize–mustard systems, more so with residue addition. When no residue was added, conventional tillage required 20% higher energy inputs than the zero tillage, while the residue addition increased the energy output in both tillage practices. Maize–wheat–greengram cropping system involved the maximum energy requirement and the cost of production. However, the largest net return was obtained from the maize–chickpea–greengram system under the conventional tillage with residue incorporation. Although zero tillage resulted in better aggregation, C content and N availability in soil, and reduced the energy inputs, cultivation of summer greengram appeared to be profitable under conventional tillage system with residue incorporation.

  2. Ribosomal S6 Kinase Cooperates with Casein Kinase 2 to Modulate the Drosophila Circadian Molecular Oscillator

    Science.gov (United States)

    Akten, Bikem; Tangredi, Michelle M.; Jauch, Eike; Roberts, Mary A.; Ng, Fanny; Raabe, Thomas; Jackson, F. Rob

    2009-01-01

    There is a universal requirement for post-translational regulatory mechanisms in circadian clock systems. Previous work in Drosophila has identified several kinases, phosphatases and an E3 ligase that are critical for determining the nuclear translocation and/or stability of clock proteins. The present study evaluated the function of p90 ribosomal S6 kinase (RSK) in the Drosophila circadian system. In mammals, RSK1 is a light- and clock-regulated kinase known to be activated by the MAPK pathway, but there is no direct evidence that it functions as a component of the circadian system. Here, we show that Drosophila S6KII RNA displays rhythms in abundance, indicative of circadian control. Importantly, an S6KII null mutant exhibits a short-period circadian phenotype that can be rescued by expression of the wild-type gene in clock neurons, indicating a role for S6KII in the molecular oscillator. Peak PER clock protein expression is elevated in the mutant, indicative of enhanced stability, whereas per mRNA level is decreased, consistent with enhanced feedback repression. Gene reporter assays show that decreased S6KII is associated with increased PER repression. Surprisingly, we demonstrate a physical interaction between S6KII and the Casein Kinase 2 regulatory subunit (CK2β), suggesting a functional relationship between the two kinases. In support of such a relationship, there are genetic interactions between S6KII and CK2 mutations, in vivo, which indicate that CK2 activity is required for S6KII action. We propose that the two kinases cooperate within clock neurons to fine-tune circadian period, improving the precision of the clock mechanism. PMID:19144847

  3. A stochastic logical system approach to model and optimal control of cyclic variation of residual gas fraction in combustion engines

    International Nuclear Information System (INIS)

    Wu, Yuhu; Kumar, Madan; Shen, Tielong

    2016-01-01

    Highlights: • An in-cylinder pressure based measuring method for the RGF is derived. • A stochastic logical dynamical model is proposed to represent the transient behavior of the RGF. • The receding horizon controller is designed to reduce the variance of the RGF. • The effectiveness of the proposed model and control approach is validated by the experimental evidence. - Abstract: In four stroke internal combustion engines, residual gas from the previous cycle is an important factor influencing the combustion quality of the current cycle, and the residual gas fraction (RGF) is a popular index to monitor the influence of residual gas. This paper investigates the cycle-to-cycle transient behavior of the RGF in the view of systems theory and proposes a multi-valued logic-based control strategy for attenuation of RGF fluctuation. First, an in-cylinder pressure sensor-based method for measuring the RGF is provided by following the physics of the in-cylinder transient state of four-stroke internal combustion engines. Then, the stochastic property of the RGF is examined based on statistical data obtained by conducting experiments on a full-scale gasoline engine test bench. Based on the observation of the examination, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF, and with the model an optimal feedback control law, which targets on rejection of the RGF fluctuation, is derived in the framework of stochastic logical system theory. Finally, experimental results are demonstrated to show the effectiveness of the proposed model and the control strategy.

  4. Innovative bioelectrochemical-anaerobic-digestion integrated system for ammonia recovery and bioenergy production from ammonia-rich residues

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia (NH4+/NH3) inhibition during anaerobic digestion process is one of the most frequent problems existing in biogas plants, resulting in unstable process and reduced biogas production. In this study, we developed a novel hybrid system, consisted of a submersed microbial resource recovery cell...... (SMRC) and a continuous stirred tank reactor (CSTR), to prevent ammonia toxicity during anaerobic digestion by in-situ ammonia recovery and electricity production (Figure 1). In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L with an average recovery rate of 0.18 g...... of ammonia recovery on the microbial community composition in the integrated system. Results clearly indicate the great potential of the SMRC-CSTR-coupled system for efficient and cost-effective ammonia recovery, energy production and treatment of ammonia-rich residues....

  5. Effect of cataract surgery on regulation of circadian rhythms

    DEFF Research Database (Denmark)

    Erichsen, Jesper Høiberg; Brøndsted, Adam E; Kessel, Line

    2015-01-01

    was evaluated based on the principles described in the Grading of Recommendations Assessment, Development, and Evaluation system. A literature search of PubMed, Embase, and Cochrane Library databases was performed, as well as a search for unpublished trials at the U.S. National Institutes of Health Clinical......UNLABELLED: This review looked at the effect of cataract surgery on the regulation of circadian rhythms and compared the effect of blue light-filtering and clear intraocular lenses (IOLs) on circadian rhythms. A systematic review and metaanalysis were performed, and the level of evidence...... improved regulation of circadian rhythms measured by the PSQI questionnaire, but the clinical relevance is uncertain. There was no difference between the effect of the 2 IOL types. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned....

  6. Ovariectomy influences the circadian rhythm of locomotor activity and the photic phase shifts in the volcano mouse.

    Science.gov (United States)

    Juárez-Tapia, Cinthia; Miranda-Anaya, Manuel

    2017-12-01

    Recently, the relationship between the circadian system and female reproduction has been of great interest; ovarian hormones can modify the amount and distribution of daily activity differently in rodent species. The volcano mouse Neotomodon alstoni is a species in which it is possible to study the circadian rhythm of locomotion, and it offers comparative information about the influence of ovaries on the circadian system. In this study, we used infrared crossings to compare free movement in intact and sham-operated or ovariectomized mice. We analyzed behavioral and endocrine changes related to the estrous cycle and locomotor circadian rhythm in free-running mice and photic phase shifting. Evidence shows that intact mice present a scalloped pattern of daily activity during the estrous cycle. In constant darkness, the ovariectomy reduces the total amount of activity, shortens the free-running circadian period of locomotion and increases photic phase shifts during the early subjective night. During entrainment, the ovariectomized mice increased the amplitude of total activity during the scotophase, and delay the time of activity onset. These results suggest that ovarian hormones in N. alstoni modulate the circadian rhythm of locomotor activity in a species-specific manner. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Application of an ex vivo cellular model of circadian variation for bipolar disorder research: a proof of concept study.

    Science.gov (United States)

    Bamne, Mikhil N; Ponder, Christine A; Wood, Joel A; Mansour, Hader; Frank, Ellen; Kupfer, David J; Young, Michael W; Nimgaonkar, Vishwajit L

    2013-09-01

    Disruption of circadian function has been observed in several human disorders, including bipolar disorder (BD). Research into these disorders can be facilitated by human cellular models that evaluate external factors (zeitgebers) that impact circadian pacemaker activity. Incorporating a firefly luciferase reporter system into human fibroblasts provides a facile, bioluminescent readout that estimates circadian phase, while leaving the cells intact. We evaluated whether this system can be adapted to clinical BD research and whether it can incorporate zeitgeber challenge paradigms. Fibroblasts from patients with bipolar I disorder (BD-I) (n = 13) and controls (n = 12) were infected ex vivo with a lentiviral reporter incorporating the promoter sequences for Bmal1, a circadian gene to drive expression of the firefly luciferase gene. Following synchronization, the bioluminescence was used to estimate period length. Phase response curves (PRCs) were also generated following forskolin challenge and the phase response patterns were characterized. Period length and PRCs could be estimated reliably from the constructs. There were no significant case-control differences in period length, with a nonsignificant trend for differences in PRCs following the phase-setting experiments. An ex vivo cellular fibroblast-based model can be used to investigate circadian function in BD-I. It can be generated from specific individuals and this could usefully complement ongoing circadian clinical research. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. The clock in the cell: Entrainment of the circadian clock in Neurospora crassa

    OpenAIRE

    Madeti Jyothi-Boesl, Cornelia

    2008-01-01

    Since reports of daily leaf movements 2000 years ago, a so-called circadian clock (‘circa diem’ meaning ‘about a day’) has been described in organisms from almost all phyla. The work presented in this thesis gives special emphasis on the circadian clock in the fungus Neurospora crassa, a rather simple cellular system. Neurospora was used to elucidate basic clock mechanisms are that are comparable to those in more complex organisms. To that end, we investigated chronoecological questions as we...

  9. Adaptive Control of Non-Minimum Phase Modal Systems Using Residual Mode Filters2. Parts 1 and 2

    Science.gov (United States)

    Balas, Mark J.; Frost, Susan

    2011-01-01

    Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. This paper will be divided into two parts. Here in Part I we will review the basic adaptive control approach and introduce the primary ideas. In Part II, we will present the RMF methodology and complete the proofs of all our results. Also, we will apply the above theoretical results to a simple flexible structure example to illustrate the behavior with and without the residual mode filter.

  10. Catalyst systems in the production of biodiesel from residual oil; Sistemas cataliticos na producao de biodiesel por meio de oleo residual

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Carlos Alexandre de [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)

    2006-07-01

    The vegetable oils and fat animals appear like an alternative for substitution the diesel oil in ignition engines for compression. Submitting the oil on transesterification reaction, we obtain a fuel with same characteristics as diesel, called biodiesel. Generally, 85 per cent of biodiesel cost is from the oil production. Through transesterification vegetable oil can be transformed in a mixture of esters of fatty acids. The residual oil from frying has been used as a possibility of raw materials of biodiesel, due to its easy acquisition and the viability of not being discarded as waste. (author)

  11. Circadian aspects of post-operative morbidity and mortality

    DEFF Research Database (Denmark)

    Kvaslerud, T.; Hansen, M.V.; Rosenberg, J.

    2010-01-01

    concerning post-operative circadian disturbances. We also present the literature concerning circadian variation in post-operative morbidity and mortality. PubMed and the Cochrane database were searched for papers using a combination of 'circadian,' 'surgery,' 'post-operative,' 'mortality' and 'morbidity....... There is a peak incidence of myocardial ischemia, fatal thromboembolism and sudden unexpected death in the morning hours. A circadian variation exists in post-operative morbidity and mortality. The observed circadian variation in post-operative morbidity and mortality may warrant a chronopharmacological approach...

  12. Plant circadian clocks increase photosynthesis, growth, survival, and competitive advantage.

    Science.gov (United States)

    Dodd, Antony N; Salathia, Neeraj; Hall, Anthony; Kévei, Eva; Tóth, Réka; Nagy, Ferenc; Hibberd, Julian M; Millar, Andrew J; Webb, Alex A R

    2005-07-22

    Circadian clocks are believed to confer an advantage to plants, but the nature of that advantage has been unknown. We show that a substantial photosynthetic advantage is conferred by correct matching of the circadian clock period with that of the external light-dark cycle. In wild type and in long- and short-circadian period mutants of Arabidopsis thaliana, plants with a clock period matched to the environment contain more chlorophyll, fix more carbon, grow faster, and survive better than plants with circadian periods differing from their environment. This explains why plants gain advantage from circadian control.

  13. Characterization of circadian behavior in the starlet sea anemone, Nematostella vectensis.

    Directory of Open Access Journals (Sweden)

    William D Hendricks

    Full Text Available Although much is known about how circadian systems control daily cycles in the physiology and behavior of Drosophila and several vertebrate models, marine invertebrates have often been overlooked in circadian rhythms research. This study focuses on the starlet sea anemone, Nematostella vectensis, a species that has received increasing attention within the scientific community for its potential as a model research organism. The recently sequenced genome of N. vectensis makes it an especially attractive model for exploring the molecular evolution of circadian behavior. Critical behavioral data needed to correlate gene expression patterns to specific behaviors are currently lacking in N. vectensis.To detect the presence of behavioral oscillations in N. vectensis, locomotor activity was evaluated using an automated system in an environmentally controlled chamber. Animals exposed to a 24 hr photoperiod (12 hr light: 12 hr dark exhibited locomotor behavior that was both rhythmic and predominantly nocturnal. The activity peak occurred in the early half of the night with a 2-fold increase in locomotion. Upon transfer to constant lighting conditions (constant light or constant dark, an approximately 24 hr rhythm persisted in most animals, suggesting that the rhythm is controlled by an endogenous circadian mechanism. Fourier analysis revealed the presence of multiple peaks in some animals suggesting additional rhythmic components could be present. In particular, an approximately 12 hr oscillation was often observed. The nocturnal increase in generalized locomotion corresponded to a 24 hr oscillation in animal elongation.These data confirm the presence of a light-entrainable circadian clock in Nematostella vectensis. Additional components observed in some individuals indicate that an endogenous clock of approximately 12 hr frequency may also be present. By describing rhythmic locomotor behavior in N. vectensis, we have made important progress in developing

  14. Impact testing of the residual limb: System response to changes in prosthetic stiffness.

    Science.gov (United States)

    Boutwell, Erin; Stine, Rebecca; Gard, Steven

    2016-01-01

    Currently, it is unknown whether changing prosthetic limb stiffness affects the total limb stiffness and influences the shock absorption of an individual with transtibial amputation. The hypotheses tested within this study are that a decrease in longitudinal prosthetic stiffness will produce (1) a reduced total limb stiffness, and (2) reduced magnitude of peak impact forces and increased time delay to peak force. Fourteen subjects with a transtibial amputation participated in this study. Prosthetic stiffness was modified by means of a shock-absorbing pylon that provides reduced longitudinal stiffness through compression of a helical spring within the pylon. A sudden loading evaluation device was built to examine changes in limb loading mechanics during a sudden impact event. No significant change was found in the peak force magnitude or timing of the peak force between prosthetic limb stiffness conditions. Total limb stiffness estimates ranged from 14.9 to 17.9 kN/m but were not significantly different between conditions. Thus, the prosthetic-side total limb stiffness was unaffected by changes in prosthetic limb stiffness. The insensitivity of the total limb stiffness to prosthetic stiffness may be explained by the mechanical characteristics (i.e., stiffness and damping) of the anatomical tissue within the residual limb.

  15. Analysis of 10 systemic pesticide residues in various baby foods using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yang, Angel; Abd El-Aty, A M; Park, Jong-Hyouk; Goudah, Ayman; Rahman, Md Musfiqur; Do, Jung-Ah; Choi, Ok-Ja; Shim, Jae-Han

    2014-06-01

    Ten systemic pesticides, comprising methomyl, thiamethoxam, acetamiprid, carbofuran, fosthiazate, metalaxyl, azoxystrobin, diethofencarb, propiconazole, and difenoconazole, were detected in 13 baby foods (cereals, boiled potatoes, fruit and milk) using QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) for sample preparation and liquid chromatography tandem mass spectrometry for analysis. The matrix-matched calibration curves showed good linearity with determination coefficients (R(2) ) >0.992. The limits of detection and quantitation were 0.0015-0.003 and 0.005-0.01 mg/kg, respectively. The mean recoveries of three different concentrations ranged from 69.2 to 127.1% with relative standard deviations market, and none of the samples were found to contain pesticide residues. This method is suitable for the identification and quantification of systemic pesticides with matrix-matched standards in various baby foods. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Interface stress in socket/residual limb with transtibial prosthetic suspension systems during locomotion on slopes and stairs.

    Science.gov (United States)

    Eshraghi, Arezoo; Abu Osman, Noor Azuan; Gholizadeh, Hossien; Ali, Sadeeq; Abas, Wan Abu Bakar Wan

    2015-01-01

    This study aimed to compare the effects of different suspension methods on the interface stress inside the prosthetic sockets of transtibial amputees when negotiating ramps and stairs. Three transtibial prostheses, with a pin/lock system, a Seal-In system, and a magnetic suspension system, were created for the participants in a prospective study. Interface stress was measured as the peak pressure by using the F-socket transducers during stairs and ramp negotiation. Twelve individuals with transtibial amputation managed to complete the experiments. During the stair ascent and descent, the greatest peak pressure was observed in the prosthesis with the Seal-In system. The magnetic prosthetic suspension system caused significantly different peak pressure at the anterior proximal region compared with the pin/lock (P = 0.022) and Seal-In (P = 0.001) during the stair ascent. It was also observed during the stair descent and ramp negotiation. The prostheses exhibited varying pressure profiles during the stair and ramp ascent. The prostheses with the pin/lock and magnetic suspension systems exhibited lower peak pressures compared with the Seal-In system. The intrasystem pressure distribution at the anterior and posterior regions of the residual limb was fairly homogenous during the stair and ramp ascent and descent. Nevertheless, the intrasystem pressure mapping revealed a significant difference among the suspension types, particularly at the anterior and posterior sensor sites.

  17. Circadian and Circalunar Clock Interactions in a Marine Annelid

    Directory of Open Access Journals (Sweden)

    Juliane Zantke

    2013-10-01

    Full Text Available Life is controlled by multiple rhythms. Although the interaction of the daily (circadian clock with environmental stimuli, such as light, is well documented, its relationship to endogenous clocks with other periods is little understood. We establish that the marine worm Platynereis dumerilii possesses endogenous circadian and circalunar (monthly clocks and characterize their interactions. The RNAs of likely core circadian oscillator genes localize to a distinct nucleus of the worm’s forebrain. The worm’s forebrain also harbors a circalunar clock entrained by nocturnal light. This monthly clock regulates maturation and persists even when circadian clock oscillations are disrupted by the inhibition of casein kinase 1δ/ε. Both circadian and circalunar clocks converge on the regulation of transcript levels. Furthermore, the circalunar clock changes the period and power of circadian behavior, although the period length of the daily transcriptional oscillations remains unaltered. We conclude that a second endogenous noncircadian clock can influence circadian clock function.

  18. Circadian rhythm in succinate dehydrogenase activity in Neurospora crassa

    Directory of Open Access Journals (Sweden)

    Claudia Patricia Álvarez Barón

    2004-07-01

    Full Text Available Neurospora crassa is a widely studied model of circadian rhythmicity. In this fungus, metabolism is controlled by multiple factors which include development, medium characteristics and the circadian clock. The study of the circadian control of metabolism in this fungus could be masked by the use of restrictive media that inhibit growth and development. In this report, the presence of a circadian rhythm in the activity of the enzyme Succinate Dehydrogenase in Neurospora crassa is demonstrated. Rhythmic and arrhythmic Neurospora strains were grown in complete medium without conidiation restriction. A circadian change in the enzymatic activity was found with high values in hours corresponding to the night and a low level during the day. This finding highlights the importance of deeper studies in the circadian control of metabolism in this fungus, given the existence of multiple pathways of regulation of metabolic enzymes and a circadian clock control at the transcriptional and post-transcriptional levels.

  19. Melatonin is required for the circadian regulation of sleep.

    Science.gov (United States)

    Gandhi, Avni V; Mosser, Eric A; Oikonomou, Grigorios; Prober, David A

    2015-03-18

    Sleep is an evolutionarily conserved behavioral state whose regulation is poorly understood. A classical model posits that sleep is regulated by homeostatic and circadian mechanisms. Several factors have been implicated in mediating the homeostatic regulation of sleep, but molecules underlying the circadian mechanism are unknown. Here we use animals lacking melatonin due to mutation of arylalkylamine N-acetyltransferase 2 (aanat2) to show that melatonin is required for circadian regulation of sleep in zebrafish. Sleep is dramatically reduced at night in aanat2 mutants maintained in light/dark conditions, and the circadian regulation of sleep is abolished in free-running conditions. We find that melatonin promotes sleep downstream of the circadian clock as it is not required to initiate or maintain circadian rhythms. Additionally, we provide evidence that melatonin may induce sleep in part by promoting adenosine signaling, thus potentially linking circadian and homeostatic control of sleep. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. FM-to-AM modulations induced by a weak residual reflection stack of sine-modulated pulses in inertial confinement fusion laser systems

    Science.gov (United States)

    Huang, Xiaoxia; Deng, Xuewei; Zhou, Wei; Hu, Dongxia; Guo, Huaiwen; Wang, Yuancheng; Zhao, Bowang; Zhong, Wei; Deng, Wu

    2018-02-01

    We report on frequency to amplitude modulation (FM-to-AM) conversion induced by a weak residual reflection stack of sine-modulated pulses in a complex laser system. Theoretical and experimental investigations reveal that when weak residual reflected pulses stack on the main pulse, the spectral intensity changes in the stacked region, which then converts to obvious AM. This kind of FM-to-AM effect often occurs in the tail of the pulse and cannot be eliminated by common compensation methods, which even enhance the modulation depth. Furthermore, the actual intensity modulation frequency and depth induced by the residual reflection stack are much higher and deeper than observed on the oscilloscope, which is harmful for safe operation of the laser facility and the driving power balance during inertial confinement fusion. To eliminate this kind of FM-to-AM effect, any possible on-axis and near-axis residual reflection in laser systems must be avoided.

  1. Evaluation of dose due to the liberation of the radioactive content present in systems of final disposal of radioactive residues

    International Nuclear Information System (INIS)

    Amado, V.; Lopez, F.

    2006-01-01

    The disposal systems of radioactive residuals well-known as repositories near to the surface, are used to dispose residuals that can contain high concentrations of radionuclides of period of short semi disintegration, which they would decay at levels radiologically insignificant in some few decades or in some centuries: and acceptably low concentrations of radionuclides of period of long semi disintegration. The dose that would receive the critic group due to these systems it could be increased by cause of discreet events that affect the foreseen retard time, or by the gradual degradation of the barriers. To this last case it contributes the presence of water, because it implies leaching and dissolution that can give place to radionuclide concentrations in the underground water greater to the prospective ones. The dosimetric evaluation is important because it offers useful objective information to decide if a given repository is adjusted to the purposes of its design and it fulfills the regulatory requirements. In this work a simplified evaluation of the dose that would receive the critic group due to the liberation of contained radionuclides in a hypothetical system of final disposition of radioactive residuals is presented. For it, they are considered representative values of the usually contained activities in this type of systems and they are carried out some approaches of the source term. The study is developed in two stages. In the first one, by means of the Radionuclide pollutant scattering pattern in phreatic aquifers (DRAF) it is considered the scattering of the pollutants in the phreatic aquifer, until the discharge point in the course of the nearest surface water. This model, developed originally in the regulatory branch of the National Commission of Argentine Atomic Energy (CNEA); it solves the transport equation of solutes in porous means in three dimensions, by the finite differences method having in account the soil retention and the radioactive

  2. Identification of human circadian genes based on time course gene expression profiles by using a deep learning method.

    Science.gov (United States)

    Cui, Peng; Zhong, Tingyan; Wang, Zhuo; Wang, Tao; Zhao, Hongyu; Liu, Chenglin; Lu, Hui

    2017-12-12

    Circadian genes express periodically in an approximate 24-h period and the identification and study of these genes can provide deep understanding of the circadian control which plays significant roles in human health. Although many circadian gene identification algorithms have been developed, large numbers of false positives and low coverage are still major problems in this field. In this study we constructed a novel computational framework for circadian gene identification using deep neural networks (DNN) - a deep learning algorithm which can represent the raw form of data patterns without imposing assumptions on the expression distribution. Firstly, we transformed time-course gene expression data into categorical-state data to denote the changing trend of gene expression. Two distinct expression patterns emerged after clustering of the state data for circadian genes from our manually created learning dataset. DNN was then applied to discriminate the aperiodic genes and the two subtypes of periodic genes. In order to assess the performance of DNN, four commonly used machine learning methods including k-nearest neighbors, logistic regression, naïve Bayes, and support vector machines were used for comparison. The results show that the DNN model achieves the best balanced precision and recall. Next, we conducted large scale circadian gene detection using the trained DNN model for the remaining transcription profiles. Comparing with JTK_CYCLE and a study performed by Möller-Levet et al. (doi: https://doi.org/10.1073/pnas.1217154110), we identified 1132 novel periodic genes. Through the functional analysis of these novel circadian genes, we found that the GTPase superfamily exhibits distinct circadian expression patterns and may provide a molecular switch of circadian control of the functioning of the immune system in human blood. Our study provides novel insights into both the circadian gene identification field and the study of complex circadian-driven biological

  3. Disruption of the Circadian Clock in Mice Increases Intestinal Permeability and Promotes Alcohol-Induced Hepatic Pathology and Inflammation.

    Directory of Open Access Journals (Sweden)

    Keith C Summa

    Full Text Available The circadian clock orchestrates temporal patterns of physiology and behavior relative to the environmental light:dark cycle by generating and organizing transcriptional and biochemical rhythms in cells and tissues throughout the body. Circadian clock genes have been shown to regulate the physiology and function of the gastrointestinal tract. Disruption of the intestinal epithelial barrier enables the translocation of proinflammatory bacterial products, such as endotoxin, across the intestinal wall and into systemic circulation; a process that has been linked to pathologic inflammatory states associated with metabolic, hepatic, cardiovascular and neurodegenerative diseases - many of which are commonly reported in shift workers. Here we report, for the first time, that circadian disorganization, using independent genetic and environmental strategies, increases permeability of the intestinal epithelial barrier (i.e., gut leakiness in mice. Utilizing chronic alcohol consumption as a well-established model of induced intestinal hyperpermeability, we also found that both genetic and environmental circadian disruption promote alcohol-induced gut leakiness, endotoxemia and steatohepatitis, possibly through a mechanism involving the tight junction protein occludin. Circadian organization thus appears critical for the maintenance of intestinal barrier integrity, especially in the context of injurious agents, such as alcohol. Circadian disruption may therefore represent a previously unrecognized risk factor underlying the susceptibility to or development of alcoholic liver disease, as well as other conditions associated with intestinal hyperpermeability and an endotoxin-triggered inflammatory state.

  4. SKIP Is a Component of the Spliceosome Linking Alternative Splicing and the Circadian Clock in Arabidopsis[W

    Science.gov (United States)

    Wang, Xiaoxue; Wu, Fangming; Xie, Qiguang; Wang, Huamei; Wang, Ying; Yue, Yanling; Gahura, Ondrej; Ma, Shuangshuang; Liu, Lei; Cao, Ying; Jiao, Yuling; Puta, Frantisek; McClung, C. Robertson; Xu, Xiaodong; Ma, Ligeng

    2012-01-01

    Circadian clocks generate endogenous rhythms in most organisms from cyanobacteria to humans and facilitate entrainment to environmental diurnal cycles, thus conferring a fitness advantage. Both transcriptional and posttranslational mechanisms are prominent in the basic network architecture of circadian systems. Posttranscriptional regulation, including mRNA processing, is emerging as a critical step for clock function. However, little is known about the molecular mechanisms linking RNA metabolism to the circadian clock network. Here, we report that a conserved SNW/Ski-interacting protein (SKIP) domain protein, SKIP, a splicing factor and component of the spliceosome, is involved in posttranscriptional regulation of circadian clock genes in Arabidopsis thaliana. Mutation in SKIP lengthens the circadian period in a temperature-sensitive manner and affects light input and the sensitivity of the clock to light resetting. SKIP physically interacts with the spliceosomal splicing factor Ser/Arg-rich protein45 and associates with the pre-mRNA of clock genes, such as PSEUDORESPONSE REGULATOR7 (PRR7) and PRR9, and is necessary for the regulation of their alternative splicing and mRNA maturation. Genome-wide investigations reveal that SKIP functions in regulating alternative splicing of many genes, presumably through modulating recognition or cleavage of 5′ and 3′ splice donor and acceptor sites. Our study addresses a fundamental question on how the mRNA splicing machinery contributes to circadian clock function at a posttranscriptional level. PMID:22942380

  5. Genetic adaptation of the human circadian clock to day-length latitudinal variations and relevance for affective disorders.

    Science.gov (United States)

    Forni, Diego; Pozzoli, Uberto; Cagliani, Rachele; Tresoldi, Claudia; Menozzi, Giorgia; Riva, Stefania; Guerini, Franca R; Comi, Giacomo P; Bolognesi, Elisabetta; Bresolin, Nereo; Clerici, Mario; Sironi, Manuela

    2014-01-01

    The temporal coordination of biological processes into daily cycles is a common feature of most living organisms. In humans, disruption of circadian rhythms is commonly observed in psychiatric diseases,including schizophrenia, bipolar disorder, depression and autism. Light therapy is the most effective treatment for seasonal affective disorder and circadian-related treatments sustain antidepressant response in bipolar disorder patients. Day/night cycles represent a major circadian synchronizing signal and vary widely with latitude. We apply a geographically explicit model to show that out-of-Africa migration, which led humans to occupy a wide latitudinal area, affected the evolutionary history of circadian regulatory genes. The SNPs we identify using this model display consistent signals of natural selection using tests based on population genetic differentiation and haplotype homozygosity. Signals of natural selection driven by annual photoperiod variation are detected for schizophrenia, bipolar disorder, and restless leg syndrome risk variants, in line with the circadian component of these conditions. Our results suggest that human populations adapted to life at different latitudes by tuning their circadian clock systems. This process also involves risk variants for neuropsychiatric conditions, suggesting possible genetic modulators for chronotherapies and candidates for interaction analysis with photoperiod-related environmental variables, such as season of birth, country of residence, shift-work or lifestyle habits.

  6. Hypothalamic neurosecretory and circadian vasopressinergic neuronal systems in the blind cone-rod homeobox knock out mouse (Crx(-/-) ) and the 129sv wild type mouse

    DEFF Research Database (Denmark)

    Rovsing, Louise; Rath, Martin Fredensborg; Møller, Morten

    2013-01-01

    magnocellular and parvocellular vasopressinergic systems in both genotypes. We here present a detailed mapping of all classical hypothalamo-pituitary and accessory magnocellular nuclei and neurons in the hypothalamus by use of immunohistochemistry and in situ hybridization in both genotypes. Semiquantitative...... in situ hybridization revealed a very high expression of Avp-mRNA in all the magnocellular nuclei compared to a much lower level in the parvocellular suprachiasmatic nucleus. In a series of mice killed every 4 hours, The Avp-mRNA expression in the SCN showed a significant daily rhythm with a zenith...

  7. Transcutaneous electrical nerve stimulation (TENS) improves circadian rhythm disturbances in Alzheimer disease

    NARCIS (Netherlands)

    van Someren, E. J.; Scherder, E. J.; Swaab, D. F.

    1998-01-01

    In patients with Alzheimer disease (AD), an irregular day-night rhythm with behavioral restlessness during the night makes a strong demand on caregivers and is among the most important reasons for institutionalization. A dysfunctioning circadian timing system is supposed to underlie the disturbance

  8. Circadian modulation of GABA function in the rat suprachiasmatic nucleus: excitatory effects during the night phase.

    NARCIS (Netherlands)

    De Jeu, M.T.G.; Pennartz, C.M.A.

    2002-01-01

    Gramicidin-perforated patch-clamp recordings were made from slices of the suprachiasmatic nucleus (SCN) of adult rats to characterize the role of gamma-amino butyric acid (GABA) in the circadian timing system. During the day, activation of GABA(A) receptors hyperpolarized the membrane of SCN

  9. The role of microRNAs (miRNA) in circadian rhythmicity

    Indian Academy of Sciences (India)

    2008-12-31

    Dec 31, 2008 ... identify clock miRNAs and their function in the circadian system. .... rithms have been developed to recognize the 'seed' region to identify putative target genes, and their predictions may not always overlap. Currently, four different depositories of ... cence induced by serum starvation is associated with trans-.

  10. Circadian and age-related modulation of thermoception and temperature regulation: mechanisms and functional implications.

    NARCIS (Netherlands)

    van Someren, E.J.W.; Raymann, RJEM; Scherder, E.J.A.; Daanen, H.A.M.; Swaab, D.F.

    2002-01-01

    At older ages, the circadian rhythm of body temperature shows a decreased amplitude, an advanced phase, and decreased stability. The present review evaluates to what extent these changes may result from age-related deficiencies at several levels of the thermoregulatory system, including

  11. Circadian and age-related modulation of thermoreception and temperature regulation: mechanisms and functional implications

    NARCIS (Netherlands)

    van Someren, Eus J. W.; Raymann, Roy J. E. M.; Scherder, Erik J. A.; Daanen, Hein A. M.; Swaab, Dick F.

    2002-01-01

    At older ages, the circadian rhythm of body temperature shows a decreased amplitude, an advanced phase, and decreased stability. The present review evaluates to what extent these changes may result from age-related deficiencies at several levels of the thermoregulatory system, including

  12. Non-peptide oxytocin receptor ligands and hamster circadian wheel running rhythms.

    Science.gov (United States)

    Gannon, Robert L

    2014-10-17

    The synchronization of circadian rhythms in sleep, endocrine and metabolic functions with the environmental light cycle is essential for health, and dysfunction of this synchrony is thought to play a part in the development of many neurological disorders. There is a demonstrable need to develop new therapeutics for the treatment of neurological disorders such as depression and schizophrenia, and oxytocin is currently being investigated for this purpose. There are no published reports describing activity of oxytocin receptor ligands on mammalian circadian rhythms and that, then, is the purpose of this study. Non-peptide oxytocin receptor ligands that cross the blood brain barrier were systemically injected in hamsters to determine their ability to modulate light-induced phase advances and delays of circadian wheel running rhythms. The oxytocin receptor agonist WAY267464 (10 mg/kg) inhibited light induced phase advances of wheel running rhythms by 55%, but had no effect on light-induced phase delays. In contrast, the oxytocin receptor antagonist WAY162720 (10 mg/kg) inhibited light-induced phase delays by nearly 75%, but had no effect on light-induced phase advances. Additionally, WAY162720 was able to antagonize the inhibitory effects of WAY267464 on light-induced phase advances. These results are consistent for a role of oxytocin in the phase-delaying effects of light on circadian activity rhythms early in the night. Therefore, oxytocin may prove to be useful in developing therapeutics for the treatment of mood disorders with a concomitant dysfunction in circadian rhythms. Investigators should also be cognizant that oxytocin ligands may negatively affect circadian rhythms during clinical trials for other conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture

    Directory of Open Access Journals (Sweden)

    Virginie Sabado

    2017-10-01

    Full Text Available Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF, which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the

  14. Melanopsin resets circadian rhythms in cells by inducing clock gene Period1

    Science.gov (United States)

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

    2014-02-01

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

  15. Mice deficient of glutamatergic signaling from intrinsically photosensitive retinal ganglion cells exhibit abnormal circadian photoentrainment.

    Directory of Open Access Journals (Sweden)

    Nicole Purrier

    Full Text Available Several aspects of behavior and physiology, such as sleep and wakefulness, blood pressure, body temperature, and hormone secretion exhibit daily oscillations known as circadian rhythms. These circadian rhythms are orchestrated by an intrinsic biological clock in the suprachiasmatic nuclei (SCN of the hypothalamus which is adjusted to the daily environmental cycles of day and night by the process of photoentrainment. In mammals, the neuronal signal for photoentrainment arises from a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs that send a direct projection to the SCN. ipRGCs also mediate other non-image-forming (NIF visual responses such as negative masking of locomotor activity by light, and the pupillary light reflex (PLR via co-release of neurotransmitters glutamate and pituitary adenylate cyclase-activating peptide (PACAP from their synaptic terminals. The relative contribution of each neurotransmitter system for the circadian photoentrainment and other NIF visual responses is still unresolved. We investigated the role of glutamatergic neurotransmission for circadian photoentrainment and NIF behaviors by selective ablation of ipRGC glutamatergic synaptic transmission in mice. Mutant mice displayed delayed re-entrainment to a 6 h phase shift (advance or delay in the light cycle and incomplete photoentrainment in a symmetrical skeleton photoperiod regimen (1 h light pulses between 11 h dark periods. Circadian rhythmicity in constant darkness also was reduced in some mutant mice. Other NIF responses such as the PLR and negative masking responses to light were also partially attenuated. Overall, these results suggest that glutamate from ipRGCs drives circadian photoentrainment and negative masking responses to light.

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

    Science.gov (United States)

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

    2017-07-01

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

  17. EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Karagul Osman

    2017-09-01

    Full Text Available Introduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material and

  18. Circadian clock components in the rat neocortex

    DEFF Research Database (Denmark)

    Rath, Martin Fredensborg; Rohde, Kristian; Fahrenkrug, Jan

    2013-01-01

    in the rat neocortex. Among these, Per1, Per2, Per3, Cry1, Bmal1, Nr1d1 and Dbp were found to exhibit daily rhythms. The amplitude of circadian oscillation in neocortical clock gene expression was damped and the peak delayed as compared with the SCN. Lesions of the SCN revealed that rhythmic clock gene...

  19. Circadian Variation in Coronary Stent Thrombosis

    NARCIS (Netherlands)

    Mahmoud, Karim D.; Lennon, Ryan J.; Ting, Henry H.; Rihal, Charanjit S.; Holmes, David R.

    Objectives We sought to determine the circadian, weekly, and seasonal variation of coronary stent thrombosis. Background Other adverse cardiovascular events such as acute myocardial infarction are known to have higher incidences during the early morning hours, Mondays, and winter months. Methods The

  20. Circadian Metabolism in the Light of Evolution

    DEFF Research Database (Denmark)

    Gerhart-Hines, Zachary; Lazar, Mitchell A.

    2015-01-01

    A review. Circadian rhythm, or daily oscillation, of behaviors and biol. processes is a fundamental feature of mammalian physiol. that has developed over hundreds of thousands of years under the continuous evolutionary pressure of energy conservation and efficiency. Evolution has fine-tuned the b...

  1. Circadian rhythms: from genes to behaviour

    Indian Academy of Sciences (India)

    located in the third ventricle of the hypothalamus by two independent groups: F. K. Stephan and Irvin ... levels of biological organization, and we have tried to represent this aspect of our discipline in this special ... nature of circadian rhythm research, because at the core of all these studies lies a genetic architecture which.

  2. Circadian rhythms in handwriting kinematics and legibility

    NARCIS (Netherlands)

    Jasper, Isabelle; Gordijn, Marijke; Haeussler, Andreas; Hermsdoerfer, Joachim

    The aim of the present study was to analyze the circadian rhythmicity in handwriting kinematics and legibility and to compare the performance between Dutch and German writers. Two subject groups underwent a 40 h sleep deprivation protocol under Constant Routine conditions either in Groningen (10

  3. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    More recently, detailed investigation leading to the anatomical, neurochemical and electrophysiological characterization of the various neuronal subgroups that comprise the circadian machinery has revealed pathways through which these neurons come together to act as a neuronal circuit. Thus the D. melanogaster ...

  4. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.

    1942-10-15

    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  5. Circadian and infradian rhythms in mood.

    Science.gov (United States)

    Mitsutake, G; Otsuka, K; Cornélissen, G; Herold, M; Günther, R; Dawes, C; Burch, J B; Watson, D; Halberg, F

    2001-01-01

    The aim of this study was to assess any variation in positive, negative and total affect recorded longitudinally; to compare the results with those from prior transverse or hybrid population studies, based on the same or a different method of mood rating; and to test for any association of mood with cardiovascular, hormonal and geophysical variables monitored concomitantly. The study approach was as follows. A clinically healthy 34-year-old man filled out the positive and negative affective scale (PANAS) questionnaire five times a day for 86 days. Systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) were also measured automatically at 30-minute intervals with an ambulatory monitor from May 19 to June 29, 2000, while different endpoints of heart rate variability (HRV) were also determined at 5-minute intervals from beat-to-beat electrocardiogram (ECG) monitoring for 42 days between May 3 and June 14, 2000, with only short interruptions while the subject took a shower and changed ECG tapes. Saliva samples were collected at the times of mood ratings for one month for later determination of melatonin and cortisol concentrations. Intervals of 24 hours of the record of each variable displaced in increments of 24 hours were analyzed by chronobiologic serial section at a trial period of 24 hours to assess the circadian characteristics as they changed from one day to another. Estimates of the midline-estimating statistic of rhythm (MESOR) and circadian amplitude and acrophase obtained on consecutive days were correlated among variables to assess any associations. The findings were as follows. Overall, a circadian rhythm was demonstrated for all variables. A positive association was noteworthy between the circadian amplitude of negative affect and the MESOR of both SBP (r= 0.363; P= 0.029) and DBP (r= 0.389; P= 0.019), suggesting that BP is raised in the presence of large swings in negative affect. Needing further validation was a weak association between

  6. Experimental and analytical studies on the passive residual heat removal system for the advanced integral type reactor

    International Nuclear Information System (INIS)

    Park, Hyun-Sik; Choi, Ki-Yong; Cho, Seok; Park, Choon-Kyung; Lee, Sung-Jae; Song, Chul-Hwa; Chung, Moon-Ki

    2004-01-01

    An experiment on the thermal-hydraulic characteristics of the passive residual heat removal system (PRHRS) for an advanced integral type reactor, SMART-P, has been performed, and its experimental results have been analyzed using a best-estimated system analysis code, MARS. The experiment is performed to investigate the performance of the passive residual heat removal system using the high temperature and high pressure thermal-hydraulic test facility (VISTA) which simulates the SMART-P. The natural circulation performance of the PRHRS, the heat transfer characteristics of the PRHRS heat exchangers and the emergency cooldown tank (ECT), and the thermal-hydraulic behavior of the primary loop are investigated. The experimental results show that the coolant flows steadily in the PRHRS loop and the heat transfer through the PRHRS heat exchanger in the emergency cooldown tank is sufficient enough to enable a natural circulation of the coolant. Analysis on a typical PRHRS test has been carried out using the MARS code. The overall trends of the calculated flow rate, pressure, temperature, and heat transfer rate in the PRHRS are similar to the experimental data. There is good agreement between the experimental data and the calculated one for the fluid temperature in the PRHRS steam line. However, the calculated fluid temperature in the PRHRS condensate line is higher, the calculated coolant outlet temperature is lower, and the heat transfer rate through the PRHRS heat exchanger is lower than the experimental data. It seems that it is due to an insufficient heat transfer modeling in the pool such as the emergency cooldown tank in the MARS calculation. (author)

  7. Quality Assurance Objectives for Nondestructive Assay with the Residues Segmented Gamma Scan Assay System at the Plutonium Finishing Plant (PFP)

    International Nuclear Information System (INIS)

    WESTSIK, G.A.

    2001-01-01

    The PFP facility utilizes a Segmented Gamma Scanner Assay System (SGSAS) to perform assays on cans of ash for WIPP characterization measurements. This report documents the conformance of SGSAS to the precision and accuracy radioassay QAOs, and reports the minimum detectable concentration (MDC). The QAO measurement runs supplied in this document were for a billet can geometry. The billet cans containing stabilized residues will be loaded into pipe overpack containers (POC) for shipment to WIPP. The measurements were performed in March, 2001 following a system reconfiguration which occurred on October 27, 2000. The actual system recalibration was performed in March 2001. The new calibration will be used for all assay data collected after October 27, 2000. No parameter changes have been made and the system has been in measurement control during this period of time. The WIPP-WAC defines four nominal test levels for NDA, which are in alpha curies and grams of weapons grade (WG) Pu. Due to intended utilization of the SGSAS system for the materials mentioned above, it is presently only being qualified for the two highest QAO ranges. The sources used for the QAO measurement are the WPP NDA Performance Demonstration Project working reference materials. This report documents the analysis of test data for the SGSAS system at the nominal 10 gram and 160 gram levels. The MDC was determined using a billet can filled with diatomaceous earth but no plutonium present. Since the system is not being qualified for TRU vs low-level waste (LLW) sorting the MDC will primarily provide verification that the detection level for the system is well below the QAO ranges for which the system is being qualified. The MDC reflects the best sensitivity for a particular assay system and specific assay conditions (i.e. count time, sample configuration) when no added radioactivity is present. As such, no radioactive sources were required for the MDC determination. As with the accuracy and precision

  8. Putative pacemakers in the eyestalk and brain of the crayfish Procambarus clarkii show circadian oscillations in levels of mRNA for crustacean hyperglycemic hormone.

    Directory of Open Access Journals (Sweden)

    Janikua Nelson-Mora

    Full Text Available Crustacean hyperglycemic hormone (CHH synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress.

  9. Putative pacemakers in the eyestalk and brain of the crayfish Procambarus clarkii show circadian oscillations in levels of mRNA for crustacean hyperglycemic hormone.

    Science.gov (United States)

    Nelson-Mora, Janikua; Prieto-Sagredo, Julio; Loredo-Ranjel, Rosaura; Fanjul-Moles, María Luisa

    2013-01-01

    Crustacean hyperglycemic hormone (CHH) synthesizing cells in the optic lobe, one of the pacemakers of the circadian system, have been shown to be present in crayfish. However, the presence of CHH in the central brain, another putative pacemaker of the multi-oscillatory circadian system, of this decapod and its circadian transcription in the optic lobe and brain have yet to be explored. Therefore, using qualitative and quantitative PCR, we isolated and cloned a CHH mRNA fragment from two putative pacemakers of the multi-oscillatory circadian system of Procambarus clarkii, the optic lobe and the central brain. This CHH transcript synchronized to daily light-dark cycles and oscillated under dark, constant conditions demonstrating statistically significant daily and circadian rhythms in both structures. Furthermore, to investigate the presence of the peptide in the central brain of this decapod, we used immunohistochemical methods. Confocal microscopy revealed the presence of CHH-IR in fibers and cells of the protocerebral and tritocerebal clusters and neuropiles, particularly in some neurons located in clusters 6, 14, 15 and 17. The presence of CHH positive neurons in structures of P. clarkii where clock proteins have been reported suggests a relationship between the circadian clockwork and CHH. This work provides new insights into the circadian regulation of CHH, a pleiotropic hormone that regulates many physiological processes such as glucose metabolism and osmoregulatory responses to stress.

  10. Real-time monitoring of circadian clock oscillations in primary cultures of mammalian cells using Tol2 transposon-mediated gene transfer strategy

    Directory of Open Access Journals (Sweden)

    Yamanaka Iori

    2010-01-01

    Full Text Available Abstract Background The circadian rhythm in mammals is orchestrated by a central pacemaker in the brain, but most peripheral tissues contain their own intrinsic circadian oscillators. The circadian rhythm is a fundamental biological system in mammals involved in the regulation of various physiological functions such as behavior, cardiovascular functions and energy metabolism. Thus, it is important to understand the correlation between circadian oscillator and physiological functions in peripheral tissues. However, it is still difficult to investigate the molecular oscillator in primary culture cells. Results In this study, we used a novel Tol2 transposon based Dbp promoter or Bmal1 promoter driven luciferase reporter vector system to detect and analyze the intrinsic molecular oscillator in primary culture cells (mouse embryonic fibroblasts, fetal bovine heart endothelial cells and rat astrocytes. The results showed circadian molecular oscillations in all examined primary culture cells. Moreover, the phase relationship between Dbp promoter driven and Bmal1 promoter driven molecular rhythms were almost anti-phase, which suggested that these reporters appropriately read-out the intrinsic cellular circadian clock. Conclusions Our results indicate that gene transfer strategy using the Tol2 transposon system of a useful and safe non-viral vector is a powerful tool for investigating circadian rhythms in peripheral tissues.

  11. An environmental assessment of electricity production from slaughterhouse residues. Linking urban, industrial and waste management systems

    International Nuclear Information System (INIS)

    Santagata, R.; Ripa, M.; Ulgiati, S.

    2017-01-01

    Highlights: • Animal by-products use for electricity generation is investigated as a case-study. • Different methodological approaches to deal with by-products are explored in LCA. • Adopting a holistic perspective is crucial to achieve a circular economy framework. - Abstract: The food processing industry continues to grow, generating large amount of organically rich waste flows per year: these processors face significant economic and environmental pressures for appropriate conversion and disposal of these waste flows. Solid waste disposal problems, mostly in highly urbanized environments, energy shortages (primarily oil) and/or high petroleum prices, as well as environmental issues such as the shrinking landfill capacity, can all be addressed by converting waste material into useful and saleable products. This paper brings to the attention a possible strategy in order to meet the general EU directives concerning the residues utilization and percentage contribution for the total energy consumption by 2020, by evaluating the use of animal by-products (category 3, as defined in the directive 2002/1774/EC) for energy purposes. Slaughterhouse waste represents an important potential source of renewable energy: on average, 40–50% of a live animal is waste, with a potential energy content close to diesel fuel. Treatment of animal waste from slaughterhouse and the subsequent conversion to electricity is investigated as a case study in the Campania Region (Italy): the animal waste undergoes a rendering process, to separate a protein-rich fraction useful for animal meal production and a fat-rich fraction, to be combusted in a diesel engine for power and heat generation (CHP). An environmental assessment of the entire process is performed by means of LCA, providing a quantitative understanding of the plant processing. The study aims to understand to what extent electricity production from animal fat is environmentally sound and if there are steps and/or components

  12. Circadian rhythms, sleep, and performance in space.

    Science.gov (United States)

    Mallis, M M; DeRoshia, C W

    2005-06-01

    Maintaining optimal alertness and neurobehavioral functioning during space operations is critical to enable the National Aeronautics and Space Administration's (NASA's) vision "to extend humanity's reach to the Moon, Mars and beyond" to become a reality. Field data have demonstrated that sleep times and performance of crewmembers can be compromised by extended duty days, irregular work schedules, high workload, and varying environmental factors. This paper documents evidence of significant sleep loss and disruption of circadian rhythms in astronauts and associated performance decrements during several space missions, which demonstrates the need to develop effective countermeasures. Both sleep and circadian disruptions have been identified in the Behavioral Health and Performance (BH&P) area and the Advanced Human Support Technology (AHST) area of NASA's Bioastronautics Critical Path Roadmap. Such disruptions could have serious consequences on the effectiveness, health, and safety of astronaut crews, thus reducing the safety margin and increasing the chances of an accident or incident. These decrements oftentimes can be difficult to detect and counter effectively in restrictive operational environments. NASA is focusing research on the development of optimal sleep/wake schedules and countermeasure timing and application to help mitigate the cumulative effects of sleep and circadian disruption and enhance operational performance. Investing research in humans is one of NASA's building blocks that will allow for both short- and long-duration space missions and help NASA in developing approaches to manage and overcome the human limitations of space travel. In addition to reviewing the current state of knowledge concerning sleep and circadian disruptions during space operations, this paper provides an overview of NASA's broad research goals. Also, NASA-funded research, designed to evaluate the relationships between sleep quality, circadian rhythm stability, and

  13. Direct residue analysis of systemic insecticides and some of their relevant metabolites in wines by liquid chromatography - mass spectrometry.

    Science.gov (United States)

    Berset, J D; Mermer, S; Robel, A E; Walton, V M; Chien, M L; Field, J A

    2017-07-14

    A direct large volume injection (DI-LVI) high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS) method was developed and validated for the quantitative determination of 16 systemic insecticides and their main plant metabolites. The assays were conducted on commercial red and white wines made from grapes grown in major wine-producing regions nationally and internationally. Using a 1:20 dilution and an injection volume of 800μL, a limit of quantitation (LOQ) of 1μgL -1 for all analytes was achieved. Matrix-matched standards (MM) were used for accurate quantitation. Imidacloprid (IMI) and methoxyfenozide (MET) were the most frequently detected parent insecticides in the wines reaching concentrations of 1-132μgL -1 . Two important plant metabolites imidacloprid-olefin (IMI-OLE) and spirotetramat-enol (SPT-EN) were found at higher concentrations. In five samples SPT-EN was detected in the mgL -1 range with a maximum concentration of 16.3mgL -1 measured in a conventional white wine sample. Most "organic" wines contained no detectable or low insecticide residues, except for one sample, which showed the highest IMI (14.7μgL -1 ) and IMI-OLE (331μgL -1 ) concentrations. Considering the maximum residue limit (MRL) definition for the different insecticides, three "conventional" wine samples were non-compliant for SPT. This study highlights the importance to determine both parent and metabolite forms of systemic insecticides in the finished product. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Case study: Is the 'catch-all-plastics bin' useful in unlocking the hidden resource potential in the residual waste collection system?

    Science.gov (United States)

    Kranzinger, Lukas; Schopf, Kerstin; Pomberger, Roland; Punesch, Elisabeth

    2017-02-01

    Austria's performance in the collection of separated waste is adequate. However, the residual waste still contains substantial amounts of recyclable materials - for example, plastics, paper and board, glass and composite packaging. Plastics (lightweight packaging and similar non-packaging materials) are detected at an average mass content of 13% in residual waste. Despite this huge potential, only 3% of the total amount of residual waste (1,687,000 t y -1 ) is recycled. This implies that most of the recyclable materials contained in the residual waste are destined for thermal recovery and are lost for recycling. This pilot project, commissioned by the Land of Lower Austria, applied a holistic approach, unique in Europe, to the Lower Austrian waste management system. It aims to transfer excess quantities of plastic packaging and non-packaging recyclables from the residual waste system to the separately collected waste system by introducing a so-called 'catch-all-plastics bin'. A quantity flow model was constructed and the results showed a realistic increase in the amount of plastics collected of 33.9 wt%. This equals a calculated excess quantity of 19,638 t y -1 . The increased plastics collection resulted in a positive impact on the climate footprint (CO 2 equivalent) in line with the targets of EU Directive 94/62/EG (Circular Economy Package) and its Amendments. The new collection system involves only moderate additional costs.

  15. QA Objectives for NDA with the Residues Segmented Gamma Scan Assay System at the Plutonium Finishing Plant (PFP)

    International Nuclear Information System (INIS)

    WESTSIK, G.A.

    2001-01-01

    The PFP facility utilizes a Segmented Gamma Scanner Assay System (SGSAS) to perform assays on cans of ash for WIPP characterization measurements. This report documents the conformance of SGSAS to the precision and accuracy radioassay QAOs, and reports the minimum detectable concentration (MDC). The QAO measurement runs supplied in this document were for a billet can geometry. The measurements were performed in August 2000. This document covers assays performed until October 27, 2000. The billet cans containing stabilized residues will be loaded into pipe overpack containers (POC) for shipment to WIPP. The WIPP-WAC defines four nominal test levels for NDA, which are in alpha curies and grams of weapons grade (WG) Pu. Due to intended utilization of the SGSAS system for the materials mentioned above, it is presently only being qualified for the two highest QAO ranges. The sources used for the QAO measurements are plutonium standards, which have been calibrated using calorimetry techniques. This report documents the analysis of test data for the SGSAS system at the nominal 10 gram and 160 gram levels. The MDC was determined using a billet can filled with diatomaceous earth but no plutonium present. Since the system is not being qualified for TRU vs low-level waste (LLW) sorting the MDC will primarily provide verification that the detection level for the system is well below the QAO ranges for which the system is being qualified. The MDC reflects the best sensitivity for a particular assay system and specific assay conditions (i.e. count time, sample configuration) when no added radioactivity is present. As such, no radioactive sources were required for the MDC determination. As with the accuracy and precision QAOs, the MDC is valid for the billet cans

  16. Neurospora COP9 signalosome integrity plays major roles for hyphal growth, conidial development, and circadian function.

    Directory of Open Access Journals (Sweden)

    Zhipeng Zhou

    Full Text Available The COP9 signalosome (CSN is a highly conserved multifunctional complex that has two major biochemical roles: cleaving NEDD8 from cullin proteins and maintaining the stability of CRL components. We used mutation analysis to confirm that the JAMM domain of the CSN-5 subunit is responsible for NEDD8 cleavage from cullin proteins in Neurospora crassa. Point mutations of key residues in the metal-binding motif (EX(nHXHX(10D of the CSN-5 JAMM domain disrupted CSN deneddylation activity without interfering with assembly of the CSN complex or interactions between CSN and cullin proteins. Surprisingly, CSN-5 with a mutated JAMM domain partially rescued the phenotypic defects observed in a csn-5 mutant. We found that, even without its deneddylation activity, the CSN can partially maintain the stability of the SCF(FWD-1 complex and partially restore the degradation of the circadian clock protein FREQUENCY (FRQ in vivo. Furthermore, we showed that CSN containing mutant CSN-5 efficiently prevents degradation of the substrate receptors of CRLs. Finally, we found that deletion of the CAND1 ortholog in N. crassa had little effect on the conidiation circadian rhythm. Our results suggest that CSN integrity plays major roles in hyphal growth, conidial development, and circadian function in N. crassa.

  17. Cholinergic and dopaminergic mechanisms involved in the recovery of circadian anticipation by aniracetam in aged rats.

    Science.gov (United States)

    Tanaka, Yushiro; Kurasawa, Mitsue; Nakamura, Kazuo

    2002-05-01

    We have reported that repeated administration of aniracetam (100 mg/kg p.o.) for 7 consecutive days recovers mealtime-associated circadian anticipatory behavior diminished in aged rats. The present study examines the mode of action underlying the restoration by aniracetam with various types of receptor antagonists. Coadministration of scopolamine (0.1 mg/kg i.p.) or haloperidol (0.1 mg/kg i.p.) for the last 3 days significantly reduced the restorative effects of aniracetam without affecting the timed feeding-induced anticipatory behavior by each receptor antagonist itself. The other receptor antagonists, mecamylamine (3 mg/kg i.p.), 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX, 1 microg/rat i.c.v.) had no effect on either the basal or aniracetam-elicited circadian anticipation. In contrast, ketanserin (1 mg/kg i.p.) itself recovered the diminished anticipatory behavior as aniracetam did, but it did not alter the restorative effects of aniracetam. Among the receptor antagonists tested, NBQX reduced appetite and haloperidol induced circadian hypoactivity. These results suggest that the food-entrainable circadian oscillations or the temporal regulatory system of behavior is modulated by cholinergic, dopaminergic and serotonergic systems. Furthermore, aniracetam may restore the aging-diminished behavioral anticipation by activating muscarinic acetylcholine (ACh) and/or dopamine (DA) D2 receptors through the enhanced release of ACh and/or DA in the brain.

  18. Signals from the brainstem sleep/wake centers regulate behavioral timing via the circadian clock.

    Directory of Open Access Journals (Sweden)

    Sabra M Abbott

    Full Text Available Sleep-wake cycling is controlled by the complex interplay between two brain systems, one which controls vigilance state, regulating the transition between sleep and wake, and the other circadian, which communicates time-of-day. Together, they align sleep appropriately with energetic need and the day-night cycle. Neural circuits connect brain stem sites that regulate vigilance state with the suprachiasmatic nucleus (SCN, the master circadian clock, but the function of these connections has been unknown. Coupling discrete stimulation of pontine nuclei controlling vigilance state with analytical chemical measurements of intra-SCN microdialysates in mouse, we found significant neurotransmitter release at the SCN and, concomitantly, resetting of behavioral circadian rhythms. Depending upon stimulus conditions and time-of-day, SCN acetylcholine and/or glutamate levels were augmented and generated shifts of behavioral rhythms. These results establish modes of neurochemical communication from brain regions controlling vigilance state to the central circadian clock, with behavioral consequences. They suggest a basis for dynamic integration across brain systems that regulate vigilance states, and a potential vulnerability to altered communication in sleep disorders.