Science.gov

Sample records for restless quiescence thermonuclear

  1. Nucleosynthesis in Thermonuclear Supernovae

    SciTech Connect

    Claudia, Travaglio; Hix, William Raphael

    2013-01-01

    We review our understanding of the nucleosynthesis that occurs in thermonuclear supernovae and their contribution to Galactic Chemical evolution. We discuss the prospects to improve the modeling of the nucleosynthesis within simulations of these events.

  2. Restless Leg Syndrome in Neurologic and Medical Disorders.

    PubMed

    Askenasy, Nadir; Askenasy, Jean-Jacques

    2015-09-01

    Adopting prior models of sleep-wake transitions, a flip-flop switch in synchronized neurotransmitter activity is proposed to underlie restless leg syndrome onset. In this model, leg quiescence homeostasis sustained through concerted activities of several neurotransmitters in basal ganglia is perturbed and produces striatal motor activity along sensory activity associated with thalamocortical circuits (conscious urge and discomfort). This model explains the association of restless leg syndrome with a wide variety of associated pathologies emphasizing that perturbed function and imbalance may occur under different steady states of neurotransmitter levels. Likewise, this concept links various central and peripheral etiologies and integrates the augmenting and transient effects of therapeutic neuromodulators.

  3. Thermonuclear land of plenty

    NASA Astrophysics Data System (ADS)

    Gasior, P.

    2014-11-01

    Since the process of energy production in the stars has been identified as the thermonuclear fusion, this mechanism has been proclaimed as a future, extremely modern, reliable and safe for sustaining energetic needs of the humankind. However, the idea itself was rather straightforward and the first attempts to harness thermonuclear reactions have been taken yet in 40s of the twentieth century, it quickly appeared that physical and technical problems of domesticating exotic high temperature medium known as plasma are far from being trivial. Though technical developments as lasers, superconductors or advanced semiconductor electronics and computers gave significant contribution for the development of the thermonuclear fusion reactors, for a very long time their efficient performance was out of reach of technology. Years of the scientific progress brought the conclusions that for the development of the thermonuclear power plants an enormous interdisciplinary effort is needed in many fields of science covering not only plasma physics but also material research, superconductors, lasers, advanced diagnostic systems (e.g. spectroscopy, interferometry, scattering techniques, etc.) with huge amounts of data to be processed, cryogenics, measurement-control systems, automatics, robotics, nanotechnology, etc. Due to the sophistication of the problems with plasma control and plasma material interactions only such a combination of the research effort can give a positive output which can assure the energy needs of our civilization. In this paper the problems of thermonuclear technology are briefly outlined and it is shown why this domain can be a broad field for the experts dealing with electronics, optoelectronics, programming and numerical simulations, who at first glance can have nothing common with the plasma or nuclear physics.

  4. Restless Legs Syndrome

    MedlinePlus

    ... Restless Legs Syndrome Share Print Restless Legs Syndrome Table of Contents1. Overview2. Symptoms3. Diagnosis4. Treatment5. Questions OverviewWhat ... twitch when you try and sleep (also called periodic limb movements of sleep or PLMS). DiagnosisHow does ...

  5. Restless legs syndrome.

    PubMed

    Bayard, Max; Avonda, Thomas; Wadzinski, James

    2008-07-15

    Restless legs syndrome is a common neurologic movement disorder that affects approximately 10 percent of adults. Of those affected with this condition, approximately one third have symptoms severe enough to require medical therapy. Restless legs syndrome may be a primary condition, or it may be secondary to iron deficiency, renal failure, pregnancy, or the use of certain medications. The diagnosis is clinical, requiring an urge to move the legs usually accompanied by an uncomfortable sensation, occurrence at rest, improvement with activity, and worsening of symptoms in the evening or at night. Restless legs syndrome causes sleep disturbances, is associated with anxiety and depression, and has a negative effect on quality of life. Treatment of secondary causes of restless legs syndrome may result in improvement or resolution of symptoms. Currently, there is little information regarding the effects of lifestyle changes on the symptoms of restless legs syndrome. If medications are needed, dopamine agonists are the primary medications for moderate to severe restless legs syndrome. Other medications that may be effective include gabapentin, carbidopa/levodopa, opioids, and benzodiazepines.

  6. Pathway parameter and thermonuclear functions

    NASA Astrophysics Data System (ADS)

    Mathai, A. M.; Haubold, H. J.

    2008-04-01

    In the theory of thermonuclear reaction rates, analytical evaluation of thermonuclear functions for non-resonant reactions, including cases with cut-off and depletion of the tail of the Maxwell-Boltzmann distribution function were considered in a series of papers by Mathai and Haubold [A.M. Mathai, H.J. Haubold, Modern Problems in Nuclear and Neutrino Astrophysics, Akademie-Verlag, Berlin, 1988]. In the present paper we study more general classes of thermonuclear functions by introducing a pathway parameter α, so that when α→1 the thermonuclear functions in the Maxwell-Boltzmannian case are recovered. We will also give interpretations for the pathway parameter α in the case of cut-off and in terms of moments. Non-extensive statistical mechanics, as developed by Tsallis [C. Tsallis, What should a statistical mechanics satisfy to reflect nature? Physica D 193 (2004) 3-34], provides the physical basis for the generalized thermonuclear functions considered in this paper.

  7. Restless legs syndrome.

    PubMed

    Venkateshiah, Saiprakash B; Ioachimescu, Octavian C

    2015-07-01

    Restless legs syndrome is a common sensorimotor disorder characterized by an urge to move, and associated with uncomfortable sensations in the legs (limbs). Restless legs syndrome can lead to sleep-onset or sleep-maintenance insomnia, and occasionally excessive daytime sleepiness, all leading to significant morbidity. Brain iron deficiency and dopaminergic neurotransmission abnormalities play a central role in the pathogenesis of this disorder, along with other nondopaminergic systems, although the exact mechanisms are still. Intensive care unit patients are especially vulnerable to have unmasking or exacerbation of restless legs syndrome because of sleep deprivation, circadian rhythm disturbance, immobilization, iron deficiency, and use of multiple medications that can antagonize dopamine. Published by Elsevier Inc.

  8. Transient nuclear Prospero induces neural progenitor quiescence.

    PubMed

    Lai, Sen-Lin; Doe, Chris Q

    2014-10-29

    Stem cells can self-renew, differentiate, or enter quiescence. Understanding how stem cells switch between these states is highly relevant for stem cell-based therapeutics. Drosophila neural progenitors (neuroblasts) have been an excellent model for studying self-renewal and differentiation, but quiescence remains poorly understood. In this study, we show that when neuroblasts enter quiescence, the differentiation factor Prospero is transiently detected in the neuroblast nucleus, followed by the establishment of a unique molecular profile lacking most progenitor and differentiation markers. The pulse of low level nuclear Prospero precedes entry into neuroblast quiescence even when the timing of quiescence is advanced or delayed by changing temporal identity factors. Furthermore, loss of Prospero prevents entry into quiescence, whereas a pulse of low level nuclear Prospero can drive proliferating larval neuroblasts into quiescence. We propose that Prospero levels distinguish three progenitor fates: absent for self-renewal, low for quiescence, and high for differentiation.

  9. Thermonuclear runaways in nova outbursts

    NASA Technical Reports Server (NTRS)

    Shankar, Anurag; Arnett, David; Fryxell, Bruce A.

    1992-01-01

    Results of exploratory, two-dimensional numerical calculations of a local thermonuclear runaway on the surface of a white dwarf are reported. It is found that the energy released by the runaway can induce a significant amount of vorticity near the burning region. Such mass motions account naturally for mixing of core matter into the envelope during the explosion. A new mechanism for the lateral spread of nuclear burning is also discussed.

  10. Black Hole Binaries in Quiescence

    NASA Astrophysics Data System (ADS)

    Bailyn, Charles D.

    I discuss some of what is known and unknown about the behavior of black hole binary systems in the quiescent accretion state. Quiescence is important for several reasons: 1) the dominance of the companion star in optical and IR wavelengths allows the binary parameters to be robustly determined - as an example, we argue that the longer proposed distance to the X-ray source GRO J1655-40 is correct; 2) quiescence represents the limiting case of an extremely low accretion rate, in which both accretion and jets can be observed; 3) understanding the evolution and duration of the quiescent state is a key factor in determining the overall demographics of X-ray binaries, which has taken on a new importance in the era of gravitational wave astronomy.

  11. Targeting Quiescence in Prostate Cancer

    DTIC Science & Technology

    2016-10-01

    G0 in the bone marrow , which renders them insensitive to chemotherapies designed to target actively proliferating cancer cells. Our goal is to...examine whether dormant DTCs enter G0 in the bone marrow and test whether the disruption of DTC quiescence may reduce tumor burden and improve treatment...dynamics, and that these cell lines respond to signals from the bone marrow thought to promote dormancy by increasing cell cycle arrest. In our xenograft

  12. [Restless legs syndrome].

    PubMed

    Lai, Szu-Chia; Chen, Rou-Shayn

    2008-03-01

    The restless legs syndrome (RLS) is a common neurological disorder to take possession of increasing attention. RLS is characterized by an urge to move the legs, usually accompanied by uncomfortable or unpleasant sensations, that occurs or worsen at rest and is relieved by activity. The symptoms of RLS have a major impact on nocturnal sleep and daytime functions. The clinical diagnostic criteria were established and published in 2003 by International Restless Legs Syndrome Study Group (IRLSSG). All four essential criteria must be met for a positive diagnosis. However, RLS encompassed an idiopathic form of genetic or unknown origin and secondary forms associated with many causes. Special awareness should be kept for differential diagnosis such as uremia, iron deficiency anemia, polyneuropathy, rheumatoid arthritis, and other neurodegenerative diseases. Polysomnography, actinography, L-dopa loading test, and suggested immobilization test (SIT) are helpful tools to reduce the diagnostic puzzle of false positive and false negative. Pathophysiological concepts of RLS are essentially based on the neuroimaging and neurophysiological data to assume a dysfunction of the dopaminergic system, possibly on the All neuron group localized in the hypothalamus. These neurons modulate spinal excitability and alter the sensory processing predominantly of leg afferents. Treatment may be closely linked to the dopaminergic system and iron metabolism. Dopaminergic stimulation with levodopa or dopamine agonists is the first choice in idiopathic restless legs syndrome, but the long-term adverse effect of augmentation should be carefully monitored.

  13. ASI regulates satiety quiescence in C. elegans.

    PubMed

    Gallagher, Thomas; Kim, Jeongho; Oldenbroek, Marieke; Kerr, Rex; You, Young-Jai

    2013-06-05

    In Caenorhabditis elegans, satiety quiescence mimics behavioral aspects of satiety and postprandial sleep in mammals. On the basis of calcium-imaging, genetics, and behavioral studies, here we report that a pair of amphid neurons, ASI, is activated by nutrition and regulates worms' behavioral states specifically promoting satiety quiescence; ASI inhibits the switch from quiescence to dwelling (a browsing state) and accelerates the switch from dwelling to quiescence. The canonical TGFβ pathway, whose ligand is released from ASI, regulates satiety quiescence. The mutants of a ligand, a receptor and SMADs in the TGFβ pathway all eat more and show less quiescence than wild-type. The TGFβ receptor in downstream neurons RIM and RIC is sufficient for worms to exhibit satiety quiescence, suggesting neuronal connection from ASI to RIM and RIC is essential for feeding regulation through the TGFβ pathway. ASI also regulates satiety quiescence partly through cGMP signaling; restoring cGMP signaling in ASI rescues the satiety quiescence defect of cGMP signaling mutants. From these results, we propose that TGFβ and cGMP pathways in ASI connect nutritional status to promotion of satiety quiescence, a sleep-like behavioral state.

  14. ASI regulates satiety quiescence in C. elegans

    PubMed Central

    Gallagher, Thomas; Kim, Jeongho; Oldenbroek, Marieke; Kerr, Rex; You, Young-Jai

    2013-01-01

    In C. elegans, satiety quiescence mimics behavioral aspects of satiety and post-prandial sleep in mammals. On the basis of calcium-imaging, genetics and behavioral studies, here we report that a pair of amphid neurons ASI is activated by nutrition and regulates worms’ behavioral states specifically promoting satiety quiescence; ASI inhibits the switch from quiescence to dwelling (a browsing state) and accelerates the switch from dwelling to quiescence. The canonical TGFβ pathway, whose ligand is released from ASI, regulates satiety quiescence. The mutants of a ligand, a receptor and SMADs in the TGFβ pathway all eat more and show less quiescence than wild type. The TGFβ receptor in downstream neurons RIM and RIC is sufficient for worms to exhibit satiety quiescence, suggesting neuronal connection from ASI to RIM and RIC is essential for feeding regulation through the TGFβ pathway. ASI also regulates satiety quiescence partly through cGMP signaling; restoring cGMP signaling in ASI rescues the satiety quiescence defect of cGMP signaling mutants. From these results, we propose that TGFβ and cGMP pathways in ASI connect nutritional status to promotion of satiety quiescence, a sleep-like behavioral state. PMID:23739968

  15. Restless legs syndrome.

    PubMed

    Ekbom, Karl; Ulfberg, J

    2009-11-01

    Restless legs syndrome (RLS) is a common neurological sensory-motor disorder that is characterized by intense restlessness and unpleasant creeping sensations deep inside the lower legs. Symptoms appear when the legs are at rest and are worst in the evening and at night. They force patients to keep moving their legs, and often to get out of bed and wander about. Periodic limb movements (PLMS) are also common during sleep amongst those suffering from RLS, and sleep efficiency is severely reduced. There are idiopathic as well as symptomatic forms of RLS, the latter being associated with e.g. pregnancy, iron deficiency and chronic renal failure. A family history of RLS is very common and pedigrees in these cases suggest an autosomal-dominant transmission with high penetrance. Genetic investigations have been performed in order to identify genes associated with RLS. Several loci have been found (on chromosomes 12q, 14q, 9p, 2q, 20p and 16p). Pathophysiology of RLS remains incompletely understood. However, advanced brain imaging studies and positive results of dopaminergic treatment suggest that RLS may be generated by dopamine dysfunction locally within the central nervous system. At present, there is a wide range of treatment options including levodopa, dopamine agonists, opioids, benzodiazepines, antiepileptic drugs and iron supplements.

  16. Transient nuclear Prospero induces neural progenitor quiescence

    PubMed Central

    Lai, Sen-Lin; Doe, Chris Q

    2014-01-01

    Stem cells can self-renew, differentiate, or enter quiescence. Understanding how stem cells switch between these states is highly relevant for stem cell-based therapeutics. Drosophila neural progenitors (neuroblasts) have been an excellent model for studying self-renewal and differentiation, but quiescence remains poorly understood. In this study, we show that when neuroblasts enter quiescence, the differentiation factor Prospero is transiently detected in the neuroblast nucleus, followed by the establishment of a unique molecular profile lacking most progenitor and differentiation markers. The pulse of low level nuclear Prospero precedes entry into neuroblast quiescence even when the timing of quiescence is advanced or delayed by changing temporal identity factors. Furthermore, loss of Prospero prevents entry into quiescence, whereas a pulse of low level nuclear Prospero can drive proliferating larval neuroblasts into quiescence. We propose that Prospero levels distinguish three progenitor fates: absent for self-renewal, low for quiescence, and high for differentiation. DOI: http://dx.doi.org/10.7554/eLife.03363.001 PMID:25354199

  17. Cosmic Chandlery with thermonuclear supernovae

    DOE PAGES

    Calder, Alan C.; Krueger, Brendan K.; Jackson, A. P.; ...

    2017-05-30

    Thermonuclear (Type Ia) supernovae are bright stellar explosions, the light curves of which can be calibrated to allow for use as "standard candles" for measuring cosmological distances. Contemporary research investigates how the brightness of an event may be influenced by properties of the progenitor system that follow from properties of the host galaxy such as composition and age. The goals are to better understand systematic effects and to assess the intrinsic scatter in the brightness, thereby reducing uncertainties in cosmological studies. We present the results from ensembles of simulations in the single-degenerate paradigm addressing the influence of age and metallicitymore » on the brightness of an event and compare our results to observed variations of brightness that correlate with properties of the host galaxy. As a result, we also present results from "hybrid" progenitor models that incorporate recent advances in stellar evolution.« less

  18. Cosmic Chandlery with Thermonuclear Supernovae

    NASA Astrophysics Data System (ADS)

    Calder, A. C.; Krueger, B. K.; Jackson, A. P.; Willcox, D. E.; Miles, B. J.; Townsley, D. M.

    2017-05-01

    Thermonuclear (Type Ia) supernovae are bright stellar explosions, the light curves of which can be calibrated to allow for use as “standard candles” for measuring cosmological distances. Contemporary research investigates how the brightness of an event may be influenced by properties of the progenitor system that follow from properties of the host galaxy such as composition and age. The goals are to better understand systematic effects and to assess the intrinsic scatter in the brightness, thereby reducing uncertainties in cosmological studies. We present the results from ensembles of simulations in the single-degenerate paradigm addressing the influence of age and metallicity on the brightness of an event and compare our results to observed variations of brightness that correlate with properties of the host galaxy. We also present results from “hybrid” progenitor models that incorporate recent advances in stellar evolution.

  19. Simulating Thermonuclear Runaway in Novae

    NASA Astrophysics Data System (ADS)

    Dursi, L. J.; Truran, J.; Zingale, M.; Calder, A. C.; Fryxell, B.; Olson, K.; Ricker, P.; Rosner, R.; Timmes, F. X.; Tufo, H. M.; MacNeice, P.

    2000-12-01

    A nova is a thought to result from a partially degenerate thermonuclear runaway on the surface of a white dwarf. Material from the underlying white dwarf must be dredged up into the atmosphere in order to produce an explosion with the observed energies; the carbon and oxygen serve as catalysts for the hydrogen burning, allowing the much more temperature-sensitive CNO burning to occur. In order to understand this dredge-up problem, we are running two different types of simulations. The first are large-scale simulations with the FLASH code (Fryxell et al., 2000), using a one-dimensional set of initial conditions of a nova about to undergo runaway created by Ami Glasner. These initial conditions have been used in previous multidimensional simulations (Glasner et al. 1997; Kercek et al. 1998), but these simulations have given widely different results because of different mixing behaviors in the two codes. Our set of simulations will shed some light on this discrepancy; since our code has adaptive mesh refinement (MacNeice et al., 2000), we can afford to highly refine the region of the star where the mixing occurs, without the cost of highly refining the entire region. Because these large-scale computations are extremely compute-intensive, they are not appropriate for broad exploration of initial conditions. To do this, we use a One-Dimensional Turbulence (ODT) model which has been used in astrophysical models previously (Niemeyer & Kerstein, 1997). This allows us to use ODT simulations of the nova as experiments to guide us to interesting regimes to study further with multidimensional FLASH code simulations. This work was supported in part by the Department of Energy Grant No. B341495 to the Center for Astrophysical Thermonuclear Flashes at the University of Chicago under the ASCI Strategic Alliances Program and by NASA/Goddard Space Flight Center

  20. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  1. Thermonuclear fusion in a strong laser field

    NASA Astrophysics Data System (ADS)

    Krainov, V. P.

    2014-08-01

    Thermonuclear fusion induced by the irradiation of solid deuterated cluster targets and foils with fields of strong femtosecond and picosecond laser pulses is discussed. The thermonuclear-fusion process D( d, n)3He in a collision of two deuterons at an energy of 50 to 100 keV in a deuterium cluster target irradiated with a strong laser pulse is discussed. A theory of thermonuclear fusion proceeding upon the irradiation of clusters formed by deuterium iodide (DI) molecules with the field of a superintense femtosecond laser pulse is developed. This theory is based on an above-barrier process in which the sequential multiple inner ionization of atomic ions within a cluster is accompanied by field-induced outer ionization. The yield of neutrons from thermonuclear fusion in a deuteron-deuteron collision after the completion of a laser pulse is calculated. The yield of neutrons is determined for the thermonuclear-fusion reaction proceeding in the interaction of an intense picosecond laser pulse with thin TiD2 foils. A multiple ionization of titanium atoms at the front edge of the laser pulse is considered. The heating of free electron occurs in induced inverse bremsstrahlung in the process of electron scattering on multiply charged titanium ions. The yield of alpha particles in the thermonuclear-fusion reaction involving protons and 11B nuclei that is induced in microdrops by a strong laser field is determined. Experimental data on laser-induced thermonuclear fusion are discussed.

  2. Restless leg syndrome in pregnancy

    PubMed Central

    Grover, Aarti; Clark-Bilodeau, Courtney

    2015-01-01

    Restless leg syndrome, more recently renamed Willis-Ekbom disease, is a condition that disrupts sleep and occurs more frequently in the pregnant population. We present a 39-year-old woman with restless legs syndrome in the third trimester and discuss the epidemiology, pathophysiology and therapeutic options in the pregnant population while highlighting the challenges posed by the lack of safety data of approved drugs. PMID:27512466

  3. Restless leg syndrome in pregnancy.

    PubMed

    Grover, Aarti; Clark-Bilodeau, Courtney; D'Ambrosio, Carolyn M

    2015-09-01

    Restless leg syndrome, more recently renamed Willis-Ekbom disease, is a condition that disrupts sleep and occurs more frequently in the pregnant population. We present a 39-year-old woman with restless legs syndrome in the third trimester and discuss the epidemiology, pathophysiology and therapeutic options in the pregnant population while highlighting the challenges posed by the lack of safety data of approved drugs.

  4. Restless legs syndrome.

    PubMed

    Klingelhoefer, Lisa; Bhattacharya, Kalyan; Reichmann, Heinz

    2016-08-01

    Restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), is a common movement disorder characterised by an uncontrollable urge to move because of uncomfortable, sometimes painful sensations in the legs with a diurnal variation and a release with movement. The pathophysiology is only partially known and a genetic component together with dopaminergic and brain iron dysregulation plays an important role. Secondary causes for RLS need to be excluded. Treatment depends on the severity and frequency of RLS symptoms, comprises non-pharmacological (eg lifestyle changes) and pharmacological interventions (eg dopaminergic medication, alpha-2-delta calcium channel ligands, opioids) and relieves symptoms only. Augmentation is the main complication of long-term dopaminergic treatment of RLS. This article will provide a clinically useful overview of RLS with provision of diagnostic criteria, differential diagnoses, possible investigations and different treatment strategies with their associated complications. © 2016 Royal College of Physicians.

  5. Controlled thermonuclear fusion, high temperature plasma physics

    NASA Astrophysics Data System (ADS)

    1985-05-01

    The primary source of nuclear energy comes from the fission process of heavy nuclei. To utilize the energy released by a thermonuclear fusion process, methods of controlling the fusion reaction were studied. This is controlled thermonuclear fusion technology. The fuel used in a thermonuclear fusion process are isotopes of hydrogen: deuterium and tritium. They can be extracted from the almost unlimited seawater. Nuclear fusion also produces very little radioactive waste. Thermonuclear fusion is a promising energy source with an almost unlimited supply; it is economical, safe, and relatively clean. Ways to raise plasma temperature to a very high level and to maintain it to allow fusion reactions to take place are studied. The physical laws of high temperature plasma was studied to reach this goal which resulted in the development of high temperature plasma physics.

  6. Ignition of thermonuclear microexplosions with antimatter

    SciTech Connect

    Shmatov, M.L.

    1994-10-01

    The use of antimatter for the indirect ignition of staged thermonuclear microexplosions is proposed. The space propulsion system based on this method may become economically acceptable earlier than that which uses only the energy of annihilation. 19 refs.

  7. Thermonuclear runaways on neutron stars

    NASA Technical Reports Server (NTRS)

    Taam, R. E.; Picklum, R. E.

    1979-01-01

    Thermonuclear runaways which develop when neutron stars of 0.476 solar masses accrete hydrogen-rich material at 10 to the -10th and 2 x 10 to the -9th solar masses/year have been followed using a numerical model. It is found that a thermal instability occurs at densities in excess of 10 to the 5th g/cu cm and that the maximum accumulated mass required to initiate the runaway is 0.7 x 10 to the -12th and 2.1 x 10 to the -12th solar masses for the mass accretion rates of 10 to the -10th and 2 x 10 to the -9th solar masses/year, respectively. Heating the of the neutron star envelope by hydrogen burning leads to the ignition of helium. The nonequilibrium burning of helium by a combination of (alpha, p), (p, gamma), and (alpha, gamma) reactions involving O-14, O-15, and other heavy nuclei provides the energy for an X-ray burst. The gross properties of these models bear suggestive resemblance to those observed for some X-ray burst sources.

  8. Restless legs syndrome. A review.

    PubMed

    O'Keeffe, S T

    1996-02-12

    Restless legs syndrome is characterized by unpleasant, deep-seated paresthesias in the legs and sometimes the arms. These sensations occur at rest and are relieved by movement. Sleep disturbance is common. Many patients also have periodic movements of sleep. Mild symptoms of restless legs occur in up to 5% of the population. Restless legs syndrome is idiopathic in most patients, but it may be the presenting feature of iron deficiency and is also common in uremia, pregnancy, diabetes mellitus, rheumatoid arthritis, and polyneuropathy. Treatment of the underlying cause, when possible, usually relieves the symptoms. For patients with severe symptoms, levodopa, bromocriptine mesylate, opioids, carbamazepine, clonazepam, and clonidine hydrochloride have proved to be effective.

  9. Restless legs syndrome in multiple system atrophy.

    PubMed

    Ghorayeb, Imad; Dupouy, Sandrine; Tison, François; Meissner, Wassilios G

    2014-12-01

    The purpose of the study was to evaluate the frequency of restless legs syndrome in 30 patients with multiple system atrophy. Eight patients complained from restless legs syndrome, their severity score was 19.4 ± 4.1. Pittsburgh Sleep Quality Index scores were significantly higher in patients with restless legs syndrome than those without (9.3 ± 3.7 vs. 4.8 ± 2.9, p = 0.00165). Periodic limb movements were found in 75% of patients with restless legs syndrome. Restless legs syndrome is more prevalent in multiple system atrophy as compared to the acknowledged prevalence in the general population.

  10. Restless legs syndrome.

    PubMed

    Miletić, Vladimir; Relja, Maja

    2011-12-01

    Being of the most frequent causes of insomnia, which in the end leads to chronic fatigue, inadequate performance of daily activities, and serious disruption of quality of living, restless legs syndrome (RLS) is nowadays not only a serious medical problem but a socio-economical one as well. Prevalence of the disorder in general population is estimated at 5 to 15%. Family history is positive in over 50% of idiopathic RLS patients which points to genetic basis of the disorder. The characteristics of the secondary or acquired form of RLS are symptoms that start later in life as well as a rapid progression of the disease. On the other hand, idiopathic RLS more often starts at a younger age and the prognoses are better. Over twenty disorders and conditions are brought in connection with secondary RLS. Although the cause of primary RLS is still unknown, there is a strong connection between central metabolism of iron as well as dopamine levels and RLS manifestation. A differential diagnosis of RLS includes a wide specter of motor and sensory disorders. Diagnosis is based on clinical features and the history of disease. To correctly diagnose idiopathic RLS one must first eliminate secondary causes of RLS and then also exclude any disorders with clinical features that mimic those of RLS. It has been estimated that some 20 to 25% of patients need pharmacological therapy. Best initial therapy is the application of nonergot dopamine agonists. Anticonvulsants, benzodiazepines and opioides can be given to patients who are refractory to dopaminergic therapy, those suffering from RLS with emphasized painful sensory component and those with RLS connected with insomnia.

  11. Microtubules move the nucleus to quiescence.

    PubMed

    Laporte, Damien; Sagot, Isabelle

    2014-01-01

    The nucleus is a cellular compartment that hosts several macro-molecular machines displaying a highly complex spatial organization. This tight architectural orchestration determines not only DNA replication and repair but also regulates gene expression. In budding yeast microtubules play a key role in structuring the nucleus since they condition the Rabl arrangement in G1 and chromosome partitioning during mitosis through their attachment to centromeres via the kinetochore proteins. Recently, we have shown that upon quiescence entry, intranuclear microtubules emanating from the spindle pole body elongate to form a highly stable bundle that spans the entire nucleus. Here, we examine some molecular mechanisms that may underlie the formation of this structure. As the intranuclear microtubule bundle causes a profound re-organization of the yeast nucleus and is required for cell survival during quiescence, we discuss the possibility that the assembly of such a structure participates in quiescence establishment.

  12. [Restless-legs syndrome].

    PubMed

    Karroum, E; Konofal, E; Arnulf, I

    2008-01-01

    Restless-legs syndrome (RLS) is a sensorimotor disorder, characterized by an irresistible urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations. It begins or worsens during periods of rest or inactivity, is partially or totally relieved by movements and is exacerbated or occurs at night and in the evening. RLS sufferers represent 2 to 3% of the general population in Western countries. Supportive criteria include a family history, the presence of periodic-leg movements (PLM) when awake or asleep and a positive response to dopaminergic treatment. The RLS phenotypes include an early onset form, usually idiopathic with a familial history and a late onset form, usually secondary to peripheral neuropathy. Recently, an atypical RLS phenotype without PLM and l-DOPA resistant has been characterized. RLS can occur in childhood and should be distinguished from attention deficit/hyperactivity disorder, growing pains and sleep complaints in childhood. RLS should be included in the diagnosis of all patients consulting for sleep complaints or discomfort in the lower limbs. It should be differentiated from akathisia, that is, an urge to move the whole body without uncomfortable sensations. Polysomnographic studies and the suggested immobilization test can detect PLM. Furthermore, an l-DOPA challenge has recently been validated to support the diagnosis of RLS. RLS may cause severe-sleep disturbances, poor quality of life, depressive and anxious symptoms and may be a risk factor for cardiovascular disease. In most cases, RLS is idiopathic. It may also be secondary to iron deficiency, end-stage renal disease, pregnancy, peripheral neuropathy and drugs, such as antipsychotics and antidepressants. The small-fiber neuropathy can mimic RLS or even trigger it. RLS is associated with many neurological and sleep disorders including Parkinson's disease, but does not predispose to these diseases. The pathophysiology of RLS includes an altered brain

  13. Neutron Stars and Thermonuclear X-ray Bursts

    NASA Technical Reports Server (NTRS)

    Bhattacharyya, Supid

    2007-01-01

    This viewgraph presentation describes neutron stars and thermonuclear x ray bursts. The contents include: 1) Neutron Stars: why do we care?; 2) Thermonuclear Bursts: why do we care?; 3) Neutron Stars: Mass, Radius and Spin: a. Continuum Spectroscopy of Bursts b. Spectral Lines from Bursts c. Timing Properties of Bursts; 4) Neutron Star Atmosphere: Thermonuclear Flame Spreading; and 5) Future Prospects and Conclusions.

  14. Plasma physics and controlled thermonuclear fusion

    SciTech Connect

    Krikorian, R. )

    1989-01-01

    This proceedings contains papers on plasma physics and controlled thermonuclear fusion. Included are the following topics: Plasma focus and Z-pinch, Review of mirror fusion research, Progress in studies of x-ray and ion-beam emission from plasma focus facilities.

  15. Thermonuclear model for high energy transients

    SciTech Connect

    Woosley, S.E.

    1982-01-01

    The thermonuclear model for x- and ..gamma..-ray bursts is discussed. Different regimes of nuclear burning are reviewed, each appropriate to a given range of (steady state) accretion rate. Accretion rates in the range 10/sup -14/ to 10/sup -8/ Msub solar y/sup -1/ all appear capable of producing x-ray transients of various durations and intervals. Modifications introduced by radiatively driven mass loss, the thermal inertia of the envelope, different burning mechanisms, and two-dimensional considerations are discussed as are difficulties encountered when the thermonuclear model is confronted with observations of rapidly recurrent bursts (less than or equal to 10 min), and super-Eddington luminosities and temperatures. Results from a numerical simulation of a combined hydrogen-helium runaway initiated at pycnonuclear density are presented for the first time. The thermonuclear model for ..gamma..-ray bursts is also reviewed and updated, particularly with regard to the breakdown of the steady state hypothesis employed in previous work. Solely on the basis of nuclear instability, ..gamma..-ray bursts of various types appear possible for a very broad variety of accretion rates (approx. 10/sup -17/ to approx. 10/sup -11/ Msub solar y/sup -1/) although other considerations may restrict this range. The thermonuclear model appears capable of yielding a great diversity of high energy transient phenomena for various accretion rates, magnetic field configurations, and neutron star envelope histories.

  16. The polonium-210 problem in thermonuclear reactor

    SciTech Connect

    Shchipakhin, O.L.; Borisov, N.B.; Churkin, S.L.

    1993-12-31

    Polonium 210 forms in the lithium-lead eutectic blanket of a thermonuclear reactor. On the basis of obtained experimental data some estimates have been calculated on the ITER blanket accident consequences. The LOCA type accident represents the failure of eutectic circuit in the process of transfusion of liquid eutectic from blanket to the tritium reprocessing plant.

  17. Laser Fusion - A New Thermonuclear Concept

    ERIC Educational Resources Information Center

    Cooper, Ralph S.

    1975-01-01

    Describes thermonuclear processes induced by interaction of a laser beam with the surface of a fuel pellet. An expanding plasma is formed which results in compression of the element. Laser and reactor technology are discussed. Pictures and diagrams are included. (GH)

  18. Laser Fusion - A New Thermonuclear Concept

    ERIC Educational Resources Information Center

    Cooper, Ralph S.

    1975-01-01

    Describes thermonuclear processes induced by interaction of a laser beam with the surface of a fuel pellet. An expanding plasma is formed which results in compression of the element. Laser and reactor technology are discussed. Pictures and diagrams are included. (GH)

  19. Restless Legs Syndrome and Leg Motor Restlessness in Parkinson's Disease

    PubMed Central

    Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Hirata, Koichi

    2015-01-01

    Sleep disturbances are important nonmotor symptoms in Parkinson's disease (PD) that are associated with a negative impact on quality of life. Restless legs syndrome (RLS), which is characterized by an urge to move the legs accompanied by abnormal leg sensations, can coexist with PD, although the pathophysiology of these disorders appears to be different. RLS and PD both respond favorably to dopaminergic treatment, and several investigators have reported a significant relationship between RLS and PD. Sensory symptoms, pain, motor restlessness, akathisia, and the wearing-off phenomenon observed in PD should be differentiated from RLS. RLS in PD may be confounded by chronic dopaminergic treatment; thus, more studies are needed to investigate RLS in drug-naïve patients with PD. Recently, leg motor restlessness (LMR), which is characterized by an urge to move the legs that does not fulfill the diagnostic criteria for RLS, has been reported to be observed more frequently in de novo patients with PD than in age-matched healthy controls, suggesting that LMR may be a part of sensorimotor symptoms intrinsic to PD. In this paper, we provide an overview of RLS, LMR, and PD and of the relationships among these disorders. PMID:26504610

  20. Numerical analysis of thermonuclear detonation in dense plasma

    NASA Astrophysics Data System (ADS)

    Avronin, Y. N.; Bunatyan, A. A.; Gadzhiyev, A. D.; Mustafin, K. A.; Nurbakov, A. S.; Pisarev, V. N.; Feoktistov, L. P.; Frolov, V. D.; Shibarshov, L. I.

    1985-01-01

    The propagation of thermonuclear combustion from the region heated to thermonuclear temperatures by an external source to the remaining part of the target was investigated. The target was a tube of inert material (gold, lead, beryllium, etc.) filled with a deuterium-tritium mixture. It was determined analytically that thermonuclear combustion can propagate from a small portion of a nonspherical target to the remainder of the target and that a steady-state thermonuclear detonation wave can be formed. The role of various physical processes in thermonuclear detonation was investigated. Shock wave is the main mechanism underlying detonation propagation. The detonation rate and intensity of the thermonuclear reaction is influenced by the leakage of heat due to transvere heat conductivity. The critical diameter for thermonuclear detonation was determined approximately for a plasma filament encased in a housing with twice the density of the fuel.

  1. [Restless legs syndrome - a review].

    PubMed

    Sveinsson, Olafur Arni; Sigurdsson, Albert Pall

    2012-01-01

    Restless legs syndrome (RLS) is a common disorder with a prevalence between 10-20% in Iceland. There are two forms of RLS, idiopathic and secondary. Symptom onset of RLS before the age of 45 suggests an idiopathic form with no known underlying cause but inheritance. Symptom onset after age of 45 indicates a secondary form with an underlying cause without inheritance. Causes for secondary forms are for example: iron depletion, uraemia and polyneuropathy. Symptoms of RLS are uncomfortable and unpleasant deep sensations in the legs that are felt at rest, accompanied by an urge to move the legs, typically just before sleep. Accompanying RLS is a sleep disturbance that can lead to daytime somnolence, decreased quality of life, poor concentration, memory problems, depression and decreased energy. Dopamine agonists are currently the first line treatment for RLS. restless legs, periodic limb movements, sleep disturbance, dopamine agonists.

  2. Merging white dwarfs and thermonuclear supernovae.

    PubMed

    van Kerkwijk, M H

    2013-06-13

    Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.

  3. Thermonuclear microdetonation macron accelerator for impact ignition

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2008-03-01

    It is proposed to replace the expensive ~150 kJ petawatt laser as a means for the fast ignition of a highly compressed dense DT target by a small flyer plate propelled to high velocities by a thermonuclear microdetonation ignited at one end of a super-pinch. It appears that this can most efficiently be done with the previously proposed modification of the dense plasma focus device, adding a high voltage relativistic electron beam emitting diode inside the coaxial plasma focus discharge tube, igniting at the end of the plasma focus pinch column a thermonuclear detonation wave, propagating in the axial direction and accelerating at the end of the pinch a flyer plate to a velocity of 103 km s-1.

  4. Epidermal stem cell diversity and quiescence

    PubMed Central

    Watt, Fiona M; Jensen, Kim B

    2009-01-01

    Mammalian epidermis is maintained by self-renewal of stem cells and terminal differentiation of their progeny. New data reveal a diversity amongst stem cells that was previously unrecognized. Different stem cell populations have different locations and differ in whether they are quiescent or actively cycling. During normal epidermal homeostasis, each stem cell population feeds a restricted number of differentiated lineages. However, in response to injury or genetic manipulation the different pools of stem cells demonstrate multi-lineage differentiation ability. While it is well established that Wnt signalling promotes hair follicle (HF) differentiation, new observations suggest a role for EGF receptor signalling in promoting differentiation of interfollicular epidermis. NFATc1 maintains quiescence in the HF, while Lrig1 exerts the same function in the junctional zone. The stage is now set for exploring the relationship between the different epidermal stem cell populations and between quiescence and lineage selection. PMID:20049729

  5. Epidermal stem cell diversity and quiescence.

    PubMed

    Watt, Fiona M; Jensen, Kim B

    2009-08-01

    Mammalian epidermis is maintained by self-renewal of stem cells and terminal differentiation of their progeny. New data reveal a diversity amongst stem cells that was previously unrecognized. Different stem cell populations have different locations and differ in whether they are quiescent or actively cycling. During normal epidermal homeostasis, each stem cell population feeds a restricted number of differentiated lineages. However, in response to injury or genetic manipulation the different pools of stem cells demonstrate multi-lineage differentiation ability. While it is well established that Wnt signalling promotes hair follicle (HF) differentiation, new observations suggest a role for EGF receptor signalling in promoting differentiation of interfollicular epidermis. NFATc1 maintains quiescence in the HF, while Lrig1 exerts the same function in the junctional zone. The stage is now set for exploring the relationship between the different epidermal stem cell populations and between quiescence and lineage selection.

  6. Drug-induced restless legs syndrome.

    PubMed

    2010-08-01

    Restless legs syndrome can be very troublesome but it has no serious physical complications. The underlying causes are unknown, but it can be triggered or aggravated by a drug. In early 2010, about 60 cases of drug-induced restless legs syndrome had been published in detail. The drugs implicated were mainly psychotropics, especially antidepressants and neuroleptics. Some drugs used to treat restless legs syndrome, especially dopaminergic drugs, can in fact aggravate symptoms. Drug-induced restless legs syndrome generally resolves when the dose is reduced or the drug is withdrawn. Dysfunction of the dopaminergic system has been implicated in some cases. In practice, when a patient presents with restless legs syndrome, the role of a drug, especially a psychotropic, should be considered. Drug withdrawal or a dose reduction may be beneficial.

  7. Clinical characteristics of leg restlessness in Parkinson's disease compared with idiopathic Restless Legs Syndrome.

    PubMed

    Zhu, Xiao-Ying; Liu, Ye; Zhang, Xiao-Jin; Yang, Wen-Hao; Feng, Ya; Ondo, William G; Tan, Eng-King; Wu, Yun-Cheng

    2015-10-15

    There is limited data on motor restlessness in Parkinson's disease (PD). Here we evaluate for clinical differences between cohorts of idiopathic Restless Legs Syndrome (iRLS), PD patients with leg restlessness, and PD with RLS. We examined 276 consecutive PD patients for leg restlessness symptoms, we compared clinical features of PD patients with RLS, PD patients with leg restlessness but not meeting RLS criteria, PD patient without RLS and iRLS. A total of 262 PD patients who satisfied the inclusion criteria were analyzed. After excluding 23 possible secondary RLS or mimics, 28 were diagnosed with RLS and 18 with leg motor restlessness (LMR). Compared with iRLS patients, PD patients with RLS or LMR had older age of RLS/LMR onset, shorter duration of leg restlessness, less positive family history, different seasonal trends and more unilaterality of leg restlessness symptom (P<0.01) which were often in accordance with dominant Parkinsonism side and related with Parkinsonism severity. PD patients with RLS/LMR had lower daily dosage (P<0.01) and shorter duration (P<0.05) of dopaminergic medication when RLS/LMR symptom onset than PD without leg restlessness. PD with LMR had less severe Parkinsonism (P<0.05) and leg restlessness (P<0.01) symptoms than PD with RLS. Clinical characteristics of PD patients with RLS and LMR were different from iRLS, differentiating these various subtypes can facilitate optimal treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Rotigotine for restless legs syndrome.

    PubMed

    Davies, Shelley

    2009-09-01

    Restless legs syndrome (RLS) is a neurological disorder related to abnormal and unpleasant sensations and movements in the legs. It usually occurs at nighttime and thus has a detrimental impact on the ability to sleep, leading to poor patient quality of life. UCB has been developing rotigotine transdermal patch system (Neupro; SPM-962) as a treatment for RLS. This system is designed to replace levels of dopamine in the body via once-daily application of the patch, in a bid to restore proper motor functioning. The rotigotine patch has been authorized for the treatment of RLS since August 2008.

  9. Epilepsy and restless legs syndrome.

    PubMed

    Geyer, James D; Geyer, Emery E; Fetterman, Zachary; Carney, Paul R

    2017-03-01

    Restless legs syndrome (RLS) is a common neurological movement disorder occurring in approximately 10% of the general population. The prevalence of moderately severe RLS is 2.7% overall (3.7% for women and 1.7% for men). Epilepsy is also a common neurological disorder with significant associated morbidity and impact on quality of life. We evaluated the severity and frequency of primary RLS in patients with localization-related temporal lobe epilepsy (TLE) and investigated the role of prodromal RLS symptoms as a warning sign and lateralizing indicator. All epilepsy patients seen in the outpatient clinic were screened for movement disorders from 2005 to 2015. Ninety-eight consecutive patients with localization-related TLE (50 right TLE and 48 left TLE) who met inclusion criteria were seen in the outpatient clinic. The control group consisted of 50 individuals with no history or immediate family history of epilepsy. Each patient was evaluated with the International Restless Legs Study Group (IRLSSG) questionnaire, NIH RLS diagnostic criteria, ferritin level, and comprehensive sleep screening including polysomnography. Furthermore, patients with obstructive sleep apnea or a definite cause of secondary restless legs syndrome such as low serum ferritin or serum iron levels were also excluded from the study. There was a significant association between the type of epilepsy and whether or not patients had RLS χ(2) (1)=10.17, p<.01, using the χ(2) Goodness of Fit Test. Based on the odds ratio, the odds of patients having RLS were 4.60 times higher if they had right temporal epilepsy than if they had left temporal epilepsy, serving as a potential lateralizing indicator. A prodromal sensation of worsening RLS occurred in some patients providing the opportunity to intervene at an earlier stage in this subgroup. We identified frequent moderate to severe RLS in patients with epilepsy. The frequency of RLS was much more common than would typically be seen in patients of similar

  10. Restless legs syndrome mimicking S1 radiculopathy.

    PubMed

    Zambelis, Th; Wolgamuth, B R; Papoutsi, S N; Economou, N T

    2016-01-01

    Α case of a chronic idiopathic form of a severe type of Restless Legs Syndrome (RLS), which developed during pregnancy and persisted after this, misdiagnosed for 34 years as radiculopathy S1, is reported. In spite of the thorough clinical and laboratory investigation, in addition to constant changes of the therapeutic approach, the diagnosis of S1 radiculopathy could not be confirmed, resulting in a chronic clinical course; the latter was characterized by relapses and remissions not attributed or linked in any way to the treatment (various types of). In fact, it was due to a routine workup in a sleep clinic, where the patient was referred because of a coincident chronic insomnia (Restless Legs Syndrome is a known and important cause of insomnia/chronic insomnia), which resulted in a proper diagnosis and treatment of this case. With the use of Restless Legs Syndrome appropriate treatment (Pramipexole 0.18 mg taken at bedtime, a dopaminergic agent and Level A recommended drug for Restless Legs Syndrome) an excellent response and immediate elimination of symptoms was achieved. Restless Legs Syndrome may present with a variety of symptoms (with the most prominent shortly being reported with the acronym URGE: Urge to move the legs usually associated with unpleasant leg sensations, Rest induces symptoms, Getting active brings relief, Evening and night deteriorate symptoms); given the fact that Restless Legs Syndrome presents with a great variety and heterogeneity of symptoms (mostly pain, dysesthesia and paresthesia), which may occur in several other diseases (the so called "RLS mimics"), proper diagnosis of Restless Legs Syndrome usually fails. Restless Legs Syndrome misinterpreted as S1 radiculopathy, to the best of our knowledge, has not been reported yet in the literature. Here, case history, clinical course and common RLS mimics are presented. Different forms of Restless Legs Syndrome manifestations, which are commonly -as in this case- misinterpreted due to their

  11. Treatment of restless legs syndrome.

    PubMed

    Comella, Cynthia L

    2014-01-01

    Restless legs syndrome (RLS) is a common disorder diagnosed by the clinical characteristics of restlessness in the legs associated often with abnormal sensations that start at rest and are improved by activity, occurring with a diurnal pattern of worsened symptoms at night and improvement in the morning. RLS is the cause of impaired quality of life in those more severely afflicted. Treatment of RLS has undergone considerable change over the last few years. Several classes of medications have demonstrated efficacy, including the dopaminergic agents and the alpha-2-delta ligands. Levodopa was the first dopaminergic agent found to be successful. However, chronic use of levodopa is frequently associated with augmentation that is defined as an earlier occurrence of symptoms frequently associated with worsening severity and sometimes spread to other body areas. The direct dopamine agonists, including ropinirole, pramipexole, and rotigotine patch, are also effective, although side effects, including daytime sleepiness, impulse control disorders, and augmentation, may limit usefulness. The alpha-2-delta ligands, including gabapentin, gabapentin enacarbil, and pregabalin, are effective for RLS without known occurrence of augmentation or impulse control disorders, although sedation and dizziness can occur. Other agents, including the opioids and clonazepam do not have sufficient evidence to recommend them as treatment for RLS, although in an individual patient, they may provide benefit.

  12. Quiescence: early evolutionary origins and universality do not imply uniformity.

    PubMed

    O'Farrell, Patrick H

    2011-12-27

    Cell cycle investigations have focused on relentless exponential proliferation of cells, an unsustainable situation in nature. Proliferation of cells, whether microbial or metazoan, is interrupted by periods of quiescence. The vast majority of cells in an adult metazoan lie quiescent. As disruptions in this quiescence are at the foundation of cancer, it will be important for the field to turn its attention to the mechanisms regulating quiescence. While often presented as a single topic, there are multiple forms of quiescence each with complex inputs, some of which are tied to conceptually challenging aspects of metazoan regulation such as size control. In an effort to expose the enormity of the challenge, I describe the differing biological purposes of quiescence, and the coupling of quiescence in metazoans to growth and to the structuring of tissues during development. I emphasize studies in the organism rather than in tissue culture, because these expose the diversity of regulation. While quiescence is likely to be a primitive biological process, it appears that in adapting quiescence to its many distinct biological settings, evolution has diversified it. Consideration of quiescence in different models gives us an overview of this diversity.

  13. Oscillations During Thermonuclear X-ray Bursts

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290Hz) has, been claimed.

  14. Symptom Severity of Restless Legs Syndrome Predicts Its Clinical Course.

    PubMed

    Lee, Chung Suk; Kim, Tae; Lee, Sumin; Jeon, Hong Jun; Bang, Young Rong; Yoon, In-Young

    2016-04-01

    This study examines the clinical course of restless legs syndrome according to its severity and factors associated with the remission of restless legs syndrome symptoms. The remission or persistence of restless legs syndrome symptoms was investigated by considering patients with restless legs syndrome at the sleep clinic of Seoul National University Bundang Hospital. All subjects were observed for at least 18 months, and an incidence of remission was defined as having no restless legs syndrome symptoms for at least 1 year. Restless legs syndrome severity was evaluated by the International Restless Legs Syndrome Study Group Rating Scale. A total of 306 patients participated in this study. Over the observation periods of 4.1 ± 1.6 years, the cumulative incidence of remission is 32.5% (95% confidence interval [CI], 27.0-38.0) and decreased with baseline restless legs syndrome severity (P < .001): 60% (95% CI, 44.9-75.1), 44% (95% CI, 34.4-53.6), and 16.7% (95% CI, 10.6-22.8) in mild, moderate, and severe to very severe restless legs syndrome cases, respectively. Most cases of remission (82/96) were observed within 1 year, and the remission occurred sooner for mild restless legs syndrome. The hazard ratios of remission by Cox proportional hazards model were lower for moderate (0.556; 95% CI, 0.340-0.909) and severe to very severe (0.193; 95% CI, 0.108-0.343) restless legs syndrome than for mild restless legs syndrome. The remission incidence was lower for those patients who had a family history of restless legs syndrome and were older at restless legs syndrome diagnosis. Mild restless legs syndrome severity, no family history, and young age at restless legs syndrome diagnosis were significant predictors of restless legs syndrome remission. More than 80% of patients with severe restless legs syndrome showed a chronic clinical course. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Genetics Home Reference: restless legs syndrome

    MedlinePlus

    ... are some genetic conditions more common in particular ethnic groups? Genetic Changes Restless legs syndrome likely results from ... medications, including certain drugs used to treat nausea, depression and other mental health disorders, colds and allergies, ...

  16. Restless Legs Syndrome -- Causes and Symptoms

    MedlinePlus

    ... Treatment Jet Lag Overview Symptoms & Self Test Treatment Narcolepsy Overview & Facts Symptoms Self-Tests & Diagnosis Treatment Restless ... Category Insomnias Insomnia Child Insomnia Short Sleeper Hypersomnias Narcolepsy Insufficient Sleep Syndrome Long Sleeper Sleep Breathing Disorders ...

  17. Update in restless legs syndrome

    PubMed Central

    Salas, Rachel E.; Gamaldo, Charlene E.; Allen, Richard P.

    2016-01-01

    Purpose of review Although restless legs syndrome (RLS) is a disorder recognized in the medical literature since the 17th century, there have only recently been significant clinical and scientific advances in diagnosis, epidemiology and understanding the disorder, mainly due to the advent of dopaminergic treatment. Recent findings Recent discoveries have uncovered the iron–dopamine connection in RLS and the basic dopaminergic pathology related to the RLS symptoms. These have led to new understanding of the morbidity of RLS and the many conditions associated with RLS, which have also supported new approaches to treatment. These developments are each briefly described here. Summary Although there has been progress in understanding, diagnosing and treating RLS, it remains an underdiagnosed and undertreated condition severely impairing functioning of patients with moderate-to-severe disease. Much work is needed to improve on current, as well as other novel therapies. PMID:20581683

  18. Arteriolar niches maintain haematopoietic stem cell quiescence

    PubMed Central

    Kunisaki, Yuya; Bruns, Ingmar; Scheiermann, Christoph; Ahmed, Jalal; Pinho, Sandra; Zhang, Dachuan; Mizoguchi, Toshihide; Wei, Qiaozhi; Lucas, Daniel; Ito, Keisuke; Mar, Jessica C.; Bergman, Aviv; Frenette, Paul S.

    2013-01-01

    Cell cycle quiescence is a critical feature contributing to haematopoietic stem cell (HSC) maintenance. Although various candidate stromal cells have been identified as potential HSC niches, the spatial localization of quiescent HSCs in the bone marrow (BM) remains unclear. Here, using a novel approach that combines whole-mount confocal immunofluorescence imaging techniques and computational modelling to analyse significant tridimensional associations among vascular structures, stromal cells and HSCs, we show that quiescent HSCs associate specifically with small arterioles that are preferentially found in endosteal BM. These arterioles are ensheathed exclusively by rare NG2+ pericytes, distinct from sinusoid-associated LepR+ cells. Pharmacological or genetic activation of HSC cell cycle alters the distribution of HSCs from NG2+ peri-arteriolar niches to LepR+ peri-sinusoidal niches. Conditional depletion of NG2+ cells induces HSC cycling and reduces functional long-term repopulating HSCs in BM. These results thus indicate that arteriolar niches are indispensable to maintain HSC quiescence. PMID:24107994

  19. Arteriolar niches maintain haematopoietic stem cell quiescence.

    PubMed

    Kunisaki, Yuya; Bruns, Ingmar; Scheiermann, Christoph; Ahmed, Jalal; Pinho, Sandra; Zhang, Dachuan; Mizoguchi, Toshihide; Wei, Qiaozhi; Lucas, Daniel; Ito, Keisuke; Mar, Jessica C; Bergman, Aviv; Frenette, Paul S

    2013-10-31

    Cell cycle quiescence is a critical feature contributing to haematopoietic stem cell (HSC) maintenance. Although various candidate stromal cells have been identified as potential HSC niches, the spatial localization of quiescent HSCs in the bone marrow remains unclear. Here, using a novel approach that combines whole-mount confocal immunofluorescence imaging techniques and computational modelling to analyse significant three-dimensional associations in the mouse bone marrow among vascular structures, stromal cells and HSCs, we show that quiescent HSCs associate specifically with small arterioles that are preferentially found in endosteal bone marrow. These arterioles are ensheathed exclusively by rare NG2 (also known as CSPG4)(+) pericytes, distinct from sinusoid-associated leptin receptor (LEPR)(+) cells. Pharmacological or genetic activation of the HSC cell cycle alters the distribution of HSCs from NG2(+) periarteriolar niches to LEPR(+) perisinusoidal niches. Conditional depletion of NG2(+) cells induces HSC cycling and reduces functional long-term repopulating HSCs in the bone marrow. These results thus indicate that arteriolar niches are indispensable for maintaining HSC quiescence.

  20. Ropinirole treatment for restless legs syndrome.

    PubMed

    Molnar, Miklos Zsolt; Fornadi, Katalin; Shapiro, Colin M

    2006-09-01

    In this paper we discuss therapy with ropinirole (known as adartrel in the United Kingdom) in patients with restless legs syndrome. Restless legs syndrome is characterized by an urge to move the legs, uncomfortable sensations in the legs and worsening of these symptoms during rest with at least temporary relief brought on by activity. Current recommendations suggest dopaminergic therapy (levodopa or dopamine receptor agonists like ropinirole) as the first-line treatment for restless legs syndrome. Based on the results of randomized, placebo-controlled, double-blind trials, we conclude that ropinirole is effective in reducing symptoms of restless legs syndrome in the general population. Ropinirole has no serious or common side effects that would limit its use significantly. Rebound and augmentation problems are relatively rarely seen with ropinirole, although properly designed comparative trials are still needed to address this question. It must be noted, however, that most published studies with ropinirole compare this drug with placebo. Very few studies have compared ropinirole with other drugs (L-dopa, gabapentin, opioids, benzodiazepines, other dopaminergic agents and selegiline hydrochloride). No cost-effectiveness trial has been published yet. Treatment of restless legs syndrome with ropinirole shows it to be effective, well-tolerated and safe and it can be used in restless legs syndrome in general.

  1. [Epidemiology of restless legs syndrome].

    PubMed

    Ghorayeb, I; Tison, F

    2009-01-01

    Restless legs syndrome (RLS) is a chronic sensorimotor disorder where patients complain of an almost irresistible urge to move their legs. This urge can often be accompanied by pain or other unpleasant sensations, it either occurs or worsens with rest particularly at night, and improves with activity. The International Restless Legs Syndrome Study Group has established four essential criteria for clinical diagnosis of RLS. Affecting an estimated 7.2 to 11.5% of the adult population, the symptoms of RLS may be associated with significant sleep disturbance and may have a negative impact on quality of life. The prevalence of RLS increases with age, and women are more frequently affected than men. In France, the estimated prevalence is 8.5%. Among sufferers, 4.4% complain of very severe symptoms. Although RLS is mainly idiopathic, several clinical conditions have been associated with it, especially iron deficiency with or without anemia, end-stage renal disease and pregnancy. These conditions may share a common pathophysiological mechanism involving a disorder of iron metabolism. By contrast, controversy persists as to whether polyneuropathy, particularly when associated with diabetes, is to be considered as an important cause of secondary RLS. This association is difficult to demonstrate as conventional electromyography is not adequate to detect small fiber neuropathy often associated with diabetes. RLS is often underdiagnosed and few subjects receive recommended RLS drug treatment. There is a clear need for complementary education to improve the accurate diagnosis of RLS. Indeed, better knowledge of this syndrome is a prerequisite to prompt an appropriate therapeutic management.

  2. Thermonuclear model for. gamma. -ray bursts

    SciTech Connect

    Woosley, S.E.

    1981-08-26

    The evolution of magnetized neutron stars with field strengths of approx. 10/sup 12/ gauss that are accreting mass onto kilometer-sized polar regions at a rate of approx. /sup 13/ M/sub 0/yr/sup -1/ is examined. Based on the results of one-dimensional calculations, one finds that stable hydrogen burning, mediated by the hot CNO-cycle, will lead to a critical helium mass in the range 10/sup 20/ to 10/sup 22/ g km/sup -2/. Owing to the extreme degeneracy of the electron gas providing pressure support, helium burning occurs as a violent thermonuclear runaway which may propagate either as a convective deflagration (Type I burst) or as a detonation wave (Type II burst). Complete combustion of helium into /sup 56/Ni releases from 10/sup 38/ to 10/sup 40/ erg km/sup -2/ and pushes hot plasma with ..beta.. > 1 above the surface of the neutron star. Rapid expansion of the plasma channels a substantial fraction of the explosion energy into magnetic field stress. Spectral properties are expected to be complex with emission from both thermal and non-thermal processes. The hard ..gamma..-outburst of several seconds softens as the event proceeds and is followed by a period, typically of several minutes duration, of softer x-ray emission as the subsurface ashes of the thermonuclear explosion cool. In this model, most ..gamma..-ray bursts currently being observed are located at a distance of several hundred parsecs and should recur on a timescale of months to centuries with convective deflagrations (Type I bursts) being the more common variety. An explanation for Jacobson-like transients is also offered.

  3. X-ray bursts and neutron-star thermonuclear flashes

    NASA Technical Reports Server (NTRS)

    Joss, P. C.

    1977-01-01

    A description is presented of a model concerning the production of X-ray bursts by thermonuclear flashes in the freshly accreted matter near the surface of an accreting neutron star. An investigation is conducted regarding the physical processes relevant to such thermonuclear flashes. It is concluded that thermonuclear flashes may account for some, but not all, of the observed X-ray burst sources. Attention is given to a neutron star undergoing accretion of mass from a binary stellar companion, aspects of energetics, nuclear reactions, and heat transport mechanisms.

  4. Neutron Stars and Thermonuclear X-ray Bursts

    NASA Technical Reports Server (NTRS)

    Bhattacharyya, Sudip

    2007-01-01

    Studies of thermonuclear X-ray bursts can be very useful to constrain the spin rate, mass and radius of a neutron star approaching EOS model of high density cold matter in the neutron star cores. +k Extensive observation and analysis of the data from the rising portions of the bursts - modeling of burst oscillations and thermonuclear flame spreading. +k Theoretical study of thermonuclear flame spreading on the rapidly spinning neutron stars should be done considering all the main physical effects (including magnetic field, nuclear energy generation, Coriolis effect, strong gravity, etc.).

  5. Understanding Neutron Stars using Thermonuclear X-ray Bursts

    NASA Technical Reports Server (NTRS)

    Bhattacharyya, S.

    2007-01-01

    Studies of thermonuclear X-ray bursts can be very useful to constrain the spin rate, mass and radius of a neutron star = EOS model of high density cold matter in the neutron star cores. Extensive observation and analysis of the data from the rising portions of the bursts = modeling of burst oscillations and thermonuclear flame spreading. Theoretical study of thermonuclear flame spreading on the rapidly spinning neutron stars should be done considering all the main physical effects (including magnetic field, nuclear energy generation, Coriolis effect, strong gravity, etc.).

  6. X-ray bursts and neutron-star thermonuclear flashes

    NASA Technical Reports Server (NTRS)

    Joss, P. C.

    1977-01-01

    A description is presented of a model concerning the production of X-ray bursts by thermonuclear flashes in the freshly accreted matter near the surface of an accreting neutron star. An investigation is conducted regarding the physical processes relevant to such thermonuclear flashes. It is concluded that thermonuclear flashes may account for some, but not all, of the observed X-ray burst sources. Attention is given to a neutron star undergoing accretion of mass from a binary stellar companion, aspects of energetics, nuclear reactions, and heat transport mechanisms.

  7. Restless abdomen: a phenotypic variant of restless legs syndrome.

    PubMed

    Pérez-Díaz, Hernando; Iranzo, Alex; Rye, David B; Santamaría, Joan

    2011-09-27

    A diagnosis of restless legs syndrome (RLS) requires an urge to move the legs in combination with sensory leg discomfort. Localization of the symptoms to other body areas in the absence of leg involvement is not recognized as part of the phenotypic spectrum of RLS. We describe 3 patients who presented with sensorimotor symptoms confined to the abdominal wall and, with the exception of not involving the legs, satisfied the primary and secondary diagnostic criteria for RLS. Patients underwent detailed clinical history, video-polysomnography, abdominal imaging, and serologic and genotyping assessment. Unpleasant abdominal symptoms emerged at night during periods of rest and were accompanied by an urge to move and temporized by movement. Patients reported sleep onset and sleep maintenance insomnia due to their abdominal symptomatology. Abdominal imaging was normal. Secondary features included periodic leg movements of sleep (PLMS), and dramatic symptom amelioration with the D(2)-D(3) dopaminergic agonist pramipexole. Two subjects were anemic. Conventional RLS emerged in one subject and resolved after dose escalation. Each subject was homozygous for the most common RLS/PLMS-associated risk allele in the BTBD9 gene. Our observations indicate that the restricted abdominal symptomatology manifest in our subjects represents a phenotypic variant of RLS. Physicians should be vigilant to the existence of this unique phenotype when encountering subjects who present with insomnia and abnormal abdominal sensations. Our experience emphasizes the importance of supportive clinical features in rendering a correct diagnosis such that the most cost-effective workups and treatment can be realized.

  8. The yeast genome undergoes significant topological reorganization in quiescence

    PubMed Central

    Rutledge, Mark T.; Russo, Mariano; Belton, Jon-Matthew; Dekker, Job; Broach, James R.

    2015-01-01

    We have examined the three-dimensional organization of the yeast genome during quiescence by a chromosome capture technique as a means of understanding how genome organization changes during development. For exponentially growing cells we observe high levels of inter-centromeric interaction but otherwise a predominance of intrachromosomal interactions over interchromosomal interactions, consistent with aggregation of centromeres at the spindle pole body and compartmentalization of individual chromosomes within the nucleoplasm. Three major changes occur in the organization of the quiescent cell genome. First, intrachromosomal associations increase at longer distances in quiescence as compared to growing cells. This suggests that chromosomes undergo condensation in quiescence, which we confirmed by microscopy by measurement of the intrachromosomal distances between two sites on one chromosome. This compaction in quiescence requires the condensin complex. Second, inter-centromeric interactions decrease, consistent with prior data indicating that centromeres disperse along an array of microtubules during quiescence. Third, inter-telomeric interactions significantly increase in quiescence, an observation also confirmed by direct measurement. Thus, survival during quiescence is associated with substantial topological reorganization of the genome. PMID:26202961

  9. Probing thermonuclear burning on accreting neutron stars

    NASA Astrophysics Data System (ADS)

    Keek, L.

    2008-12-01

    Neutron stars are the most compact stars that can be directly observed, which makes them ideal laboratories to study physics at extreme densities. Neutron stars in low-mass X-ray binaries accrete hydrogen and helium from a lower-mass companion star through Roche lobe overflow. This matter undergoes thermonuclear burning in the neutron star envelope, creating carbon and heavier elements. The fusion process may proceed in an unstable manner, resulting in a thermonuclear runaway. Within one second the entire surface is burned, which is observable as a sharp rise in the emitted X-ray flux: a type I X-ray burst. Afterwards the neutron star surface cools down on a timescale of ten to one hundred seconds. During these bursts the surface of an accreting neutron star can be observed directly, which makes them instrumental for studying this type of stars. We have studied rare kinds of X-ray bursts. One such rare burst is the superburst, which lasts a thousand times longer than an ordinary burst. Superbursts are thought to result from the explosive burning of a thick carbon layer, which lies deeper inside the neutron star, close to a layer known as the crust. A prerequisite for the occurrence of a superburst is a high enough temperature, which is set by the temperature of the crust and the heat conductivity of the envelope. The latter is lowered by the presence of heavy elements that are produced during normal X-ray bursts. Using a large set of observations from the Wide Field Camera's onboard the BeppoSAX satellite, we find that, at high accretion rate, sources which do not exhibit normal bursts likely have a longer superburst recurrence time, than the observed superburst recurrence time of one burster. We analyze in detail the first superburst from a transient source, which went into outburst only 55 days before the superburst. Recent models of the neutron star crust predict that this is too small a time to heat the crust sufficiently for superburst ignition, indicating

  10. Benzodiazepines for restless legs syndrome.

    PubMed

    Carlos, Karla; Prado, Gilmar F; Teixeira, Camila Dm; Conti, Cristiane; de Oliveira, Marcio M; Prado, Lucila Bf; Carvalho, Luciane Bc

    2017-03-20

    Restless legs syndrome (RLS) is a common disease affecting about 5% to 15% of the population. Symptoms of RLS can be severe in a minority of and can have a major impact on sleep, mostly sleep initiation, and quality of life. Benzodiazepines are drugs that can induce and maintain sleep and, hence, intuitively are thought to be beneficial to people with RLS. Altough benzodiazepines, particularly clonazepam, are used to treat RLS symptoms, a systematic review done by the American Academy of Sleep Medicine stated that benzodiazepines should not be used as a first-line treatment, although could be used as a coadjuvant therapy. To evaluate the efficacy and safety of benzodiazepine compared to placebo or other treatment for idiopathic RLS, including unconfounded trials comparing benzodiazepines versus open control. In March 2016 we searched CENTRAL, MEDLINE, Embase and LILACS We checked the references of each study and contacted study authors to identify any additional studies. We considered studies published in any language. Randomised clinical trials of benzodiazepine treatment in idiopathic RLS. We did not perform data collection and analysis, since we did not include any studies, MAIN RESULTS: We did not identify any studies that met the inclusion criteria of the review. Two cross-over studies are awaiting classification because the cross-over trials did not give data at the end of the first cross-over period. The effectiveness of benzodiazepines for RLS treatment is currently unknown.

  11. Targinact for restless legs syndrome.

    PubMed

    2016-04-01

    Idiopathic restless legs syndrome (RLS)--also known as Willis-Ekbom disease--is a neurological condition characterised by an overwhelming urge to move the legs, occurring during rest or inactivity, especially at night. Symptoms are highly variable in frequency and severity, and can affect sleep and quality of life. First-line management includes addressing precipitating or aggravating factors and providing explanation, reassurance and advice on self-help strategies. Drug therapy (e.g. a dopamine agonist) is used for patients with more severe symptoms. In December 2014, the marketing authorisation for a modified-release preparation containing oxycodone and naloxone (Targinact-Napp Pharmaceuticals) was expanded to include use in the treatment of severe to very severe RLS after failure of dopaminergic therapy.(10)Here we review the management of adults with RLS, including the place of oxycodone/naloxone. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. Pharmacotherapy for restless legs syndrome.

    PubMed

    Ferini-Strambi, Luigi; Marelli, Sara

    2014-06-01

    Restless legs syndrome (RLS) is a common condition characterized by paresthesia and an urge to move. Predominantly, symptoms occur at rest in the evening or at night, and they are alleviated by moving the affected extremity. RLS prevalence in the general population has been estimated to be approximately 5%. This review presents all options for the treatment of RLS. Pharmacological treatment should be limited to those patients who suffer from clinically relevant RLS, that is, when symptoms impair the patient's quality of life, daytime functioning, social functioning or sleep. Treatment on demand is a clinical need in some RLS patients, and medications include carbidopa/levodopa, pramipexole, ropinirole, oxycodone, methadone, codeine and tramadol. Chronic RLS should be treated with either a nonergot dopamine agonist or an α-2-δ calcium channel ligand. A dopamine agonist is a more appropriate choice in the presence of depression and overweight. As α-2-δ ligands can alleviate chronic pain and may be helpful in treating anxiety and insomnia, the presence of any of these comorbidities may favor their use. For RLS present through much of the day and night, the use of long-acting agents, such as the rotigotine patch or gabapentin enacarbil should be considered. In refractory RLS, oral prolonged release oxycodone-naloxone should be considered.

  13. Perils of a Restless Planet

    NASA Astrophysics Data System (ADS)

    Zebrowski, Ernest, Jr.

    1999-05-01

    From epidemics and earthquakes to tornados and tidal waves, the overwhelming power of nature never ceases to instill humankind with both terror and awe. As natural disasters continue to claim human lives and leave destruction in their wake, Perils of a Restless Planet examines our attempts to understand and anticipate such phenomena. Now available in paperback, this highly acclaimed book draws on actual events from ancient to present times. Coverage focuses on basic scientific inquiry, technological innovation and, ultimately, public policy to provide a lucid and riveting look at the natural events that have shaped our view of natural disasters. While shedding light on the elusive quality of nature's intermittent tantrums and the limits scientific study and laboratory replication impose on our understanding of its mercurial ways, the author extrapolates from the history of science to suggest how we may someday learn to warn and protect the vulnerable populations on our small, tempestuous planet. Compelling and informative, this book will find readers both in and outside of the scientific community.

  14. Restless legs symptoms in a patient with above knee amputations: a case of phantom restless legs.

    PubMed

    Hanna, Philip A; Kumar, Sanjeev; Walters, Arthur S

    2004-01-01

    We describe a 78-year-old gentleman who, following bilateral above-knee amputations, developed symptoms of restless legs syndrome in the absent portions of his lower extremities. These symptoms improved with dopamine agonist therapy. In addition, he later developed parkinsonism with prominent rest tremor on metoclopramide. This suggests that this individual had a dopamine-deficient state which predisposed him to both restless legs syndrome and drug-induced or drug-exacerbated parkinsonism. We propose expanding the spectrum of phantom limb phenomena to include phantom restless legs.

  15. Restless Bladder in an Elderly Woman: An Unusual Feature or a Variant of Restless Legs Syndrome?

    PubMed

    Suzuki, Keisuke; Miyamoto, Masayuki; Uchiyama, Tomoyuki; Miyamoto, Tomoyuki; Matsubara, Takeo; Hirata, Koichi

    We herein report an elderly patient with a history of restless legs syndrome (RLS) who developed unpleasant sensations in the lower abdomen and perineum. The patient' s symptoms occurred during the evening and at rest and forced the patient to void, resulting in some symptom relief. Urological examinations and spinal magnetic resonance imaging findings were unremarkable. The adjunctive use of rotigotine resolved her symptoms. The symptoms were considered to be "restless bladder". Further studies are required to elucidate whether restless bladder is an identical condition to the clinical entities of other RLS variants or whether it represents an unusual feature of RLS.

  16. Thermonuclear Reaction Rate Parameterization for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Sharp, Jacob; Kozub, Raymond L.; Smith, Michael S.; Scott, Jason; Lingerfelt, Eric

    2004-10-01

    The knowledge of thermonuclear reaction rates is vital to simulate novae, supernovae, X-ray bursts, and other astrophysical events. To facilitate dissemination of this knowledge, a set of tools has been created for managing reaction rates, located at www.nucastrodata.org. One tool is a rate parameterizer, which provides a parameterization for nuclear reaction rate vs. temperature values in the most widely used functional form. Currently, the parameterizer uses the Levenberg-Marquardt method (LMM), which requires an initial estimate of the best-fit parameters. The initial estimate is currently provided randomly from a preselected pool. To improve the quality of fits, a new, active method of selecting parameters has been developed. The parameters of each set in the pool are altered for a few iterations to replicate the input data as closely as possible. Then, the set which most nearly matches the input data (based on chi squared) is used in the LMM as the initial estimate for the final fitting procedure. A description of the new, active algorithm and its performance will be presented. Supported by the U. S. Department of Energy.

  17. Bayesian Estimation of Thermonuclear Reaction Rates

    NASA Astrophysics Data System (ADS)

    Iliadis, C.; Anderson, K. S.; Coc, A.; Timmes, F. X.; Starrfield, S.

    2016-11-01

    The problem of estimating non-resonant astrophysical S-factors and thermonuclear reaction rates, based on measured nuclear cross sections, is of major interest for nuclear energy generation, neutrino physics, and element synthesis. Many different methods have been applied to this problem in the past, almost all of them based on traditional statistics. Bayesian methods, on the other hand, are now in widespread use in the physical sciences. In astronomy, for example, Bayesian statistics is applied to the observation of extrasolar planets, gravitational waves, and Type Ia supernovae. However, nuclear physics, in particular, has been slow to adopt Bayesian methods. We present astrophysical S-factors and reaction rates based on Bayesian statistics. We develop a framework that incorporates robust parameter estimation, systematic effects, and non-Gaussian uncertainties in a consistent manner. The method is applied to the reactions d(p,γ)3He, 3He(3He,2p)4He, and 3He(α,γ)7Be, important for deuterium burning, solar neutrinos, and Big Bang nucleosynthesis.

  18. Opioids for restless legs syndrome.

    PubMed

    de Oliveira, César Osório; Carvalho, Luciane Bc; Carlos, Karla; Conti, Cristiane; de Oliveira, Marcio M; Prado, Lucila Bf; Prado, Gilmar F

    2016-06-29

    Restless legs syndrome (RLS) is a distressing and common neurological disorder that may have a huge impact in the quality of life of those with frequent and intense symptoms. Patients complain of unpleasant sensations in the legs, at or before bedtime, and feel an urge to move the legs, which improves with movement, such as walking. Symptoms start with the patient at rest (e.g. sitting or lying down), and follow a circadian pattern, increasing during the evening or at night. Many pharmacological intervention are available for RLS, including drugs used to treat Parkinson's disease (L-Dopa and dopaminergic agonists), epilepsy (anticonvulsants), anxiety (benzodiazepines), and pain (opioids). Dopaminergic drugs are those most frequently used for treatment of RLS, but some patients do not respond effectively and require other medication. Opioids, a class of medications used to treat severe pain, seem to be effective in treating RLS symptoms, and are recommended for patients with severe symptoms, because RLS and pain appear to share the same mechanism in the central nervous system. All available drugs are associated to some degree with side effects, which can impede treatment. Opioids are associated with adverse events such as constipation, tolerance, and dependence. This justifies the conduct of a systematic review to ascertain whether opioids are safe and effective for treatment of RLS. To asses the effects of opioids compared to placebo treatment for restless legs syndrome in adults. We searched the Cochrane Central Register of Controlled trials, CENTRAL 2016, issue 4 and MEDLINE, EMBASE, and LILACS up to April 2016, using a search strategy adapted by Cochraneto identify randomised clinical trials. We checked the references of each study and established personal communication with other authors to identify any additional studies. We considered publications in all languages. Randomised controlled clinical trials of opioid treatment in adults with idiopathic RLS. Two

  19. Transient translational quiescence in primordial germ cells.

    PubMed

    Oulhen, Nathalie; Swartz, S Zachary; Laird, Jessica; Mascaro, Alexandra; Wessel, Gary

    2017-02-24

    Stem cells in animals often exhibit a slow cell cycle and/or low transcriptional activity referred to as quiescence. Here we report that the translational activity in the primordial germ cells (PGCs) of the sea urchin embryo (Strongylocentrotus purpuratus) is quiescent. We measured new protein synthesis with O-propargyl-puromycin, and L-homopropargylglycine, Click-iT technologies and determined that these cells synthesize protein at only 6% the level of their adjacent somatic cells. Knock-down of translation of the RNA-binding protein Nanos2 by morpholino anti-sense oligonucleotides, or knock-out of the Nanos2 gene by CRISPR/Cas9 resulted in a significant, but partial increase (47%) in general translation specifically in the PGCs. We found that the mRNA of the translation factor eEF1A is excluded from the PGCs in a Nanos2-dependent manner, a consequence of a Nanos/Pumilio response element (PRE) in its 3'UTR. In addition to eEF1A, the cytoplasmic pH of the PGCs appears to repress translation and simply increasing the pH also significantly restores translation selectively in the PGCs. We conclude that the PGCs of this sea urchin institute parallel pathways to quiesce translation thoroughly but transiently.

  20. Symmetrically converging plane thermonuclear burn waves

    NASA Astrophysics Data System (ADS)

    Charakhch'yan, A. A.; Khishchenko, K. V.

    2013-10-01

    Five variants of a one-dimensional problem on synchronous bilateral action of two identical drivers on opposite surfaces of a plane layer of DT fuel with the normal or five times greater initial density, where the solution includes two thermonuclear burn waves propagating to meet one another at the symmetry plane, are simulated. A laser pulse with total absorption of energy at the critical density (in two variants) and a proton bunch that provides for a nearly isochoric heating (in three variants) are considered as drivers. A wide-range equation of state for the fuel, electron and ion heat conduction, self-radiation of plasma and plasma heating by α-particles are taken into account. In spite of different ways of ignition, various models of α-particle heat, whether the burn wave remains slow or transforms into the detonation wave, and regardless of way of such a transformation, the final value of the burn-up factor depends essentially on the only parameter Hρ0, where H is the half-thickness of the layer and ρ0 is the initial fuel density. This factor is about 0.35 at Hρ0 ≈ 1 g cm-2 and about 0.7 at Hρ0 ≈ 5 g cm-2. The expansion stage of the flow (after reflecting the burn or detonation wave from the symmetry plane) gives the main contribution in forming the final values of the burn-up factor and the gain at Hρ0 ≈ 1 g cm-2 and increases them approximately two times at Hρ0 ≈ 5 g cm-2. In the case of the proton driver, the final value of the gain is about 200 at Hρ0 ≈ 1 g cm-2 and about 2000 at Hρ0 ≈ 5 g cm-2. In the case of the laser driver, the above values are four times less in conformity with the difference between the driver energies.

  1. Polarized fuel for controlled thermonuclear fusion

    NASA Astrophysics Data System (ADS)

    Bartalucci, Sergio

    2017-07-01

    The use of polarized nuclei as a fuel for thermonuclear fusion reactors was suggested more than 30 years ago, providing evidence for a significant increase of the total cross section. In particular, an enhancement factor close to 1.5 is expected in the energy range below 100 keV for the dominant nuclear fusion reactions 2H + 3H → 4He + n + 17.58 MeV and 2H + 3He → 4He + p + 18.34 MeV. Furthermore, the use of polarized fuel allows one to control the ejectile trajectories, via an enhancement in the forward-backward cross section asymmetry due to polarization. This allows some control on the energy transfer from the plasma to the reactor wall or helps concentrate the neutron flux to defined wall areas. Nevertheless, this idea was received with skepticism by the relevant scientific community, due to some uncertainty in the physics of the process, the low efficiency in the production of polarized beams for injection into plasma and the apparent difficulty of preserving the ion polarization for a time long compared with nuclear burning time. But more recently, as a consequence of significant progress in the field of atomic beam sources and polarized targets, the interest in this matter has been refreshed for both inertially and magnetically confined plasmas. The possibility of implementing nuclear polarization in present and future fusion reactors is discussed in this paper. In particular, the interaction between polarized ions and magnetic fields, both static and RF, which are typically used in a Tokamak for plasma heating via ion cyclotron resonance (ICRH), is considered. Also, experimental issues for practically performing a feasibility test on a real fusion reactors are illustrated.

  2. Diagnosis and treatment of restless legs syndrome.

    PubMed

    Sales, Samantha; Sanghera, Manjit K; Klocko, David J; Stewart, R Malcolm

    2016-07-01

    Restless legs syndrome (RLS) is a disorder characterized by an irresistible urge to move the legs during rest, usually accompanied by uncomfortable sensations in the affected extremity or extremities. RLS can manifest at any age but prevalence increases with advancing age. This article describes the symptoms of RLS, associated comorbidities, and how to diagnose and manage RLS.

  3. Effect of Renal Transplantation in Restless Legs Syndrome.

    PubMed

    Kahvecioglu, Serdar; Yildiz, Demet; Buyukkoyuncu, Nilufer; Celik, Huseyin; Tufan, Fatih; Kılıç, Ahmet Kasım; Gul, Bulent; Yildiz, Abdulmecid

    2016-02-01

    Restless legs syndrome is a disorder in which patients have irresistible urge to move legs during rest. Restless legs syndrome seems to be common in end-stage renal disease. After a successful renal transplant, symptoms ameliorate with renal function improvement and restless legs syndrome is seen less in this population. Here, we aimed to investigate restless legs syndrome frequency and associated factors in renal transplant patients. In a cross-sectional study with 193 patients (116 hemodialysis patients, 45 transplant patients, and 32 controls), the presence of restless legs syndrome was assessed using the Restless Legs Syndrome Questionnaire. Medical history, demographic, and laboratory data were collected from the patients' medical records. Patients were questioned about the presence of restless legs syndrome using the Restless Legs Syndrome Questionnaire. Patients were evaluated with Beck Depression Scale for depression and Pittsburgh tests for sleep disturbances. While the rate of restless legs syndrome was similar between transplants and controls, it was significantly greater in hemodialysis patients. Hemodialysis patients and controls had similar depression scores that were higher compared with transplant patients. Pittsburgh score was similar in transplant patients and controls and significantly increased in the hemodialysis patients. The rate of insomnia was significantly higher in the hemodialysis patients compared with the other 2 groups. Logistic regression analysis revealed independent correlates of restless legs syndrome as insomnia, Beck depression score, and being on hemodialysis. Linear regression analysis showed that independent correlates of higher Pittsburgh score were higher depression score, higher age, and presence of restless legs syndrome. The prevalence of restless legs syndrome is significantly lower in transplant patients than it is in patients on maintenance dialysis. In renal transplant patients, restless legs syndrome frequency was

  4. Pallasite paleomagnetism: Quiescence of a core dynamo

    NASA Astrophysics Data System (ADS)

    Nichols, Claire I. O.; Bryson, James F. J.; Herrero-Albillos, Julia; Kronast, Florian; Nimmo, Francis; Harrison, Richard J.

    2016-05-01

    Recent paleomagnetic studies of two Main Group pallasites, the Imilac and Esquel, have found evidence for a strong, late-stage magnetic field on the parent body. It has been hypothesized that this magnetic field was generated by a core dynamo, driven by compositional convection during core solidification. Cooling models suggest that the onset of core solidification occurred ∼200 Ma after planetary accretion. Prior to core solidification, a core dynamo may have been generated by thermal convection; however a thermal dynamo is predicted to be short-lived, with a duration of ∼10 Ma to ∼40 Ma after planetary accretion. These models predict, therefore, a period of quiescence between the thermally driven dynamo and the compositionally driven dynamo, when no core dynamo should be active. To test this hypothesis, we have measured the magnetic remanence recorded by the Marjalahti and Brenham pallasites, which based on cooling-rate data locked in any magnetic field signals present ∼95 Ma to ∼135 Ma after planetary accretion, before core solidification began. The cloudy zone, a region of nanoscale tetrataenite islands within a Fe-rich matrix was imaged using X-ray photoemission electron microscopy. The recovered distribution of magnetisation within the cloudy zone suggests that the Marjalahti and Brenham experienced a very weak magnetic field, which may have been induced by a crustal remanence, consistent with the predicted lack of an active core dynamo at this time. We show that the transition from a quiescent period to an active, compositionally driven dynamo has a distinctive paleomagnetic signature, which may be a crucial tool for constraining the time of core solidification on differentiated bodies, including Earth.

  5. Thermonuclear supernova light curves: Progenitors and cosmology

    NASA Astrophysics Data System (ADS)

    Rodney, Steven A.

    Thermonuclear Supernovae (TN SNe) are an extremely important tool in modern astronomy. In their role as cosmological distance probes, they have revealed the accelerated expansion of the universe and have begun to constrain the nature of the dark energy that may be driving that expansion. The next decade will see a succession of wide-field surveys producing thousands of TNSN detections each year. Traditional methods of SN analysis, rooted in time-intensive spectroscopic follow-up, will become completely impractical. To realize the potential of this coming tide of massive data sets, we will need to extract cosmographic parameters (redshift and luminosity distance) from SN photometry without any spectroscopic support. In this dissertation, I present the Supernova Ontology with Fuzzy Templates (SOFT) method, an innovative new approach to the analysis of SN light curves. SOFT uses the framework of fuzzy set theory to perform direct comparisons of SN candidates against template light curves, simultaneously producing both classifications and cosmological parameter estimates. The SOFT method allows us to shed new light on two rich archival data sets. I revisit the IfA Deep Survey and HST GOODS to extract new and improved measurements of the TNSN rate from z=0.2 out to z=1.6. Our new analysis shows a steady increase in the TNSN rate out to z˜1, and adds support for a decrease in the rate at z=1.5. Comparing these rate measurements to theoretical models, I conclude that the progenitor scenario most favored by the collective observational data is a single degenerate model, regulated by a strong wind from the accreting white dwarf. Using a compilation of SN light curves from five recent surveys, I demonstrate that SOFT is able to derive useful constraints on cosmological models from a data set with no spectroscopic information at all. Looking ahead to the near future, I find that photometric analysis of data sets containing 2,000 SNe will be able to improve our constraints on

  6. Do spherical tokamaks have a thermonuclear future?

    NASA Astrophysics Data System (ADS)

    Mirnov, S. V.

    2012-12-01

    the potential possibility of their use in thermonuclear research.

  7. Localization of thermonuclear burning in accreting millisecond pulsars

    NASA Astrophysics Data System (ADS)

    Boutloukos, Stratos; Miller, Cole

    Nuclear-powered oscillations during Type-I X-ray bursts have so far revealed the spin of about twenty accreting millisecond pulsars in low-mass X-ray binaries. Constraining strong gravity through the emission from the hot spots on the neutron star surface requires understanding of the properties of such burst oscillations. We use adaptive mesh refinement hydrodynamical numerical computations to model the ignition and spreading of thermonuclear flames. Our preliminary simulations suggest that confinement of fuel is important for the localization of thermonuclear burning, like that required for the observed burst oscillations. This is consistent with spectral analyses of RXTE observations that we also present here. The software used in this work was in part developed by the DOE-supported ASCI/Alliances Center for Astrophysical Thermonuclear Flashes at the University of Chicago. This work was supported by NSF Grant AST0708424.

  8. Profile of altered brain iron acquisition in restless legs syndrome.

    PubMed

    Connor, James R; Ponnuru, Padmavathi; Wang, Xin-Sheng; Patton, Stephanie M; Allen, Richard P; Earley, Christopher J

    2011-04-01

    Restless legs syndrome is a neurological disorder characterized by an urgency to move the legs during periods of rest. Data from a variety of sources provide a compelling argument that the amount of iron in the brain is lower in individuals with restless legs syndrome compared with neurologically normal individuals. Moreover, a significant percentage of patients with restless legs syndrome are responsive to intravenous iron therapy. The mechanism underlying the decreased iron concentrations in restless legs syndrome brains is unknown. We hypothesize that the source of the brain iron deficit is at the blood-brain interface. Thus we analysed the expression of iron management proteins in the epithelial cells of the choroid plexus and the brain microvasculature in post-mortem tissues. The choroid plexus, obtained at autopsy, from 18 neurologically normal controls and 14 individuals who had primary restless legs syndrome was subjected to histochemical staining for iron and immunostaining for iron management proteins. Iron and heavy chain ferritin staining was reduced in the epithelial cells of choroid plexus in restless legs syndrome. Divalent metal transporter, ferroportin, transferrin and its receptor were upregulated in the choroid plexus in restless legs syndrome. Microvessels were isolated from the motor cortex of 11 restless legs syndrome and 14 control brains obtained at autopsy and quantitative immunoblot analyses was performed. Expression of heavy chain ferritin, transferrin and its receptor in the microvessels from restless legs syndrome was significantly decreased compared with the controls but divalent metal protein 1, ferroportin, prohepcidin, mitochondrial ferritin and light-chain ferritin remained unchanged. The presence of an iron regulatory protein was demonstrated in the brain microvasculature and the activity of this protein is decreased in restless legs syndrome; a finding similar to our earlier report in neuromelanin cells from the substantia nigra

  9. Profile of altered brain iron acquisition in restless legs syndrome

    PubMed Central

    Ponnuru, Padmavathi; Wang, Xin-Sheng; Patton, Stephanie M.; Allen, Richard P.; Earley, Christopher J.

    2011-01-01

    Restless legs syndrome is a neurological disorder characterized by an urgency to move the legs during periods of rest. Data from a variety of sources provide a compelling argument that the amount of iron in the brain is lower in individuals with restless legs syndrome compared with neurologically normal individuals. Moreover, a significant percentage of patients with restless legs syndrome are responsive to intravenous iron therapy. The mechanism underlying the decreased iron concentrations in restless legs syndrome brains is unknown. We hypothesize that the source of the brain iron deficit is at the blood–brain interface. Thus we analysed the expression of iron management proteins in the epithelial cells of the choroid plexus and the brain microvasculature in post-mortem tissues. The choroid plexus, obtained at autopsy, from 18 neurologically normal controls and 14 individuals who had primary restless legs syndrome was subjected to histochemical staining for iron and immunostaining for iron management proteins. Iron and heavy chain ferritin staining was reduced in the epithelial cells of choroid plexus in restless legs syndrome. Divalent metal transporter, ferroportin, transferrin and its receptor were upregulated in the choroid plexus in restless legs syndrome. Microvessels were isolated from the motor cortex of 11 restless legs syndrome and 14 control brains obtained at autopsy and quantitative immunoblot analyses was performed. Expression of heavy chain ferritin, transferrin and its receptor in the microvessels from restless legs syndrome was significantly decreased compared with the controls but divalent metal protein 1, ferroportin, prohepcidin, mitochondrial ferritin and light-chain ferritin remained unchanged. The presence of an iron regulatory protein was demonstrated in the brain microvasculature and the activity of this protein is decreased in restless legs syndrome; a finding similar to our earlier report in neuromelanin cells from the substantia

  10. Statistical methods for investigating quiescence and other temporal seismicity patterns

    USGS Publications Warehouse

    Matthews, M.V.; Reasenberg, P.A.

    1988-01-01

    We propose a statistical model and a technique for objective recognition of one of the most commonly cited seismicity patterns:microearthquake quiescence. We use a Poisson process model for seismicity and define a process with quiescence as one with a particular type of piece-wise constant intensity function. From this model, we derive a statistic for testing stationarity against a 'quiescence' alternative. The large-sample null distribution of this statistic is approximated from simulated distributions of appropriate functionals applied to Brownian bridge processes. We point out the restrictiveness of the particular model we propose and of the quiescence idea in general. The fact that there are many point processes which have neither constant nor quiescent rate functions underscores the need to test for and describe nonuniformity thoroughly. We advocate the use of the quiescence test in conjunction with various other tests for nonuniformity and with graphical methods such as density estimation. ideally these methods may promote accurate description of temporal seismicity distributions and useful characterizations of interesting patterns. ?? 1988 Birkha??user Verlag.

  11. Restless Legs Syndrome After Single Low Dose Quetiapine Administration.

    PubMed

    Soyata, Ahmet Z; Celebi, Fahri; Yargc, Lutfi I

    2016-01-01

    Restless legs syndrome is an underdiagnosed sensori-motor disorder and psychotropic drugs are one of the main secondary causes of the illness. The most common psychotropic agents that cause restless legs syndrome are antidepressants; however, antipsychotics have also been reported to induce restless legs syndrome. The prevalence, vulnerability factors and the underlying mechanism of antipsychotic-induced restless legs syndrome are unclear. A possible explanation is that dopaminergic blockade is the main precipitator of the syndrome. Quetiapine-induced restless legs syndrome is another point of interest because of its low binding to D2 receptors. We herein report the case of a restless legs syndrome that emerged after a single low dose quetiapine administration.

  12. Thermonuclear supernovae: simulations of the deflagration stage and their implications.

    PubMed

    Gamezo, Vadim N; Khokhlov, Alexei M; Oran, Elaine S; Chtchelkanova, Almadena Y; Rosenberg, Robert O

    2003-01-03

    Large-scale, three-dimensional numerical simulations of the deflagration stage of a thermonuclear supernova explosion show the formation and evolution of a highly convoluted turbulent flame in the gravitational field of an expanding carbon-oxygen white dwarf. The flame dynamics are dominated by the gravity-induced Rayleigh-Taylor instability that controls the burning rate. The thermonuclear deflagration releases enough energy to produce a healthy explosion. The turbulent flame, however, leaves large amounts of unburned and partially burned material near the star center, whereas observations that imply these materials are present only in outer layers. This disagreement could be resolved if the deflagration triggers a detonation.

  13. Restless legs syndrome and hypertension in middle-aged women.

    PubMed

    Batool-Anwar, Salma; Malhotra, Atul; Forman, John; Winkelman, John; Li, Yanping; Gao, Xiang

    2011-11-01

    Limited research suggests a relationship between restless legs syndrome and hypertension. We, therefore, assessed the relationship between restless legs syndrome and hypertension among middle-aged women. This is a cross-sectional study including 65 544 women (aged 41-58 years) participating in Nurses' Health Study II. The participants with diabetes mellitus and arthritis were excluded, because these conditions can mimic restless legs syndrome. Restless legs syndrome was assessed by a self-administered questionnaire based on the International Restless Legs Study Group criteria. Information on diagnosis of hypertension and blood pressure values were collected via questionnaires. Multivariable logistic regression models were used to analyze the relation between restless legs syndrome and hypertension, with adjustment for age, race, body mass index, physical activity, menopausal status, smoking, use of analgesics, and intake of alcohol, caffeine, folate, and iron. Compared with women with no restless legs symptoms, the multiple adjusted odds of having hypertension were 1.20 times (95% CI: 1.10-1.30; P<0.0001) higher among women with restless legs symptoms. The adjusted odds ratios for women who reported restless legs symptoms 5 to 14 times per month and ≥15 times per month were 1.06 (95% CI: 0.94-1.18) and 1.41 (95% CI: 1.24-1.61) respectively, compared with those without the symptoms (P trend: <0.0001). Greater frequency of restless legs symptoms was associated with higher concurrent systolic and diastolic blood pressures (P trend: <0.0001 for both). Women with restless legs syndrome have a higher prevalence of hypertension, and this prevalence increases with more frequent restless legs symptoms.

  14. Prevalence and Outcomes of Restless Legs Syndrome among Veterans

    DTIC Science & Technology

    2007-09-01

    SUBTITLE 5a. CONTRACT NUMBER Prevalence and Outcomes of Restless Legs Syndrome among Veterans 5b. GRANT NUMBER DAMD17-03-1-0082 5c. PROGRAM...SUPPLEMENTARY NOTES 14. ABSTRACT Background: Restless Legs Syndrome (RLS) is a commonly under diagnosed organi cause of insomnia. There is evidence...AD_________________ Award Number: DAMD17-03-1-0082 TITLE: Prevalence and Outcomes of Restless Legs

  15. NFATc1 balances quiescence and proliferation of skin stem cells

    PubMed Central

    Horsley, Valerie; Aliprantis, Antonios O.; Polak, Lisa; Glimcher, Laurie H.; Fuchs, Elaine

    2008-01-01

    Quiescent adult stem cells reside in specialized niches where they become activated to proliferate and differentiate during tissue homeostasis and injury. How stem cell quiescence is governed is poorly understood. We report here that NFATc1 is preferentially expressed by hair follicle stem cells in their niche, where it's expression is activated by BMP signaling upstream and it acts downstream to transcriptionally repress CDK4 and maintain stem cell quiescence. As stem cells become activated during hair growth, NFATc1 is downregulated, relieving CDK4 repression and activating proliferation. When calcineurin/NFATc1 signaling is suppressed, pharmacologically or via complete or conditional NFATc1 gene ablation, stem cells are activated prematurely, resulting in precocious follicular growth. Our findings may explain why patients receiving cyclosporine A for immunosuppressive therapy display excessive hair growth, and unveil a functional role for calcium-NFATc1-CDK4 circuitry in governing stem cell quiescence. PMID:18243104

  16. Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS)

    MedlinePlus

    ... Page Manual of Health Quizzes Self-Assessment Tools Tables Common Medical ... Spinal Cord, and Nerve Disorders Sleep Disorders Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome ( ...

  17. Restless Legs Syndrome and Psychiatric Disorders.

    PubMed

    Mackie, Susan; Winkelman, John W

    2015-09-01

    There are strong epidemiologic ties between restless legs syndrome (RLS) and a wide array of psychiatric conditions. Although the mechanism of this association is not fully understood, there are likely bidirectional cause-and-effect relationships. Appreciation of psychiatric comorbidity is an essential component of the treatment of RLS. Clinicians should be prepared to facilitate appropriate psychiatric treatment and consider the complex interactions between psychiatric medications, RLS medications, and the clinical course of both illnesses. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Methylene blue promotes quiescence of rat neural progenitor cells.

    PubMed

    Xie, Luokun; Choudhury, Gourav R; Wang, Jixian; Park, Yong; Liu, Ran; Yuan, Fang; Zhang, Chun-Li; Yorio, Thomas; Jin, Kunlin; Yang, Shao-Hua

    2014-01-01

    Neural stem cell-based treatment holds a new therapeutic opportunity for neurodegenerative disorders. Here, we investigated the effect of methylene blue on proliferation and differentiation of rat neural progenitor cells (NPCs) both in vitro and in vivo. We found that methylene blue inhibited proliferation and promoted quiescence of NPCs in vitro without affecting committed neuronal differentiation. Consistently, intracerebroventricular infusion of methylene blue significantly inhibited NPC proliferation at the subventricular zone (SVZ). Methylene blue inhibited mTOR signaling along with down-regulation of cyclins in NPCs in vitro and in vivo. In summary, our study indicates that methylene blue may delay NPC senescence through enhancing NPCs quiescence.

  19. Thermonuclear Fusion: An Energy Source for the Future

    ERIC Educational Resources Information Center

    Drummond, William E.

    1973-01-01

    Discusses current research in thermonuclear fusion with particular emphasis on the problem of confining hot plasma. Recent experiments indicate that magnetic bottles called tokamaks may achieve the necessary confinement times, and this break-through has given renewed optimism to the feasibility of commercial fusion power by the turn of the…

  20. Thermonuclear Fusion: An Energy Source for the Future

    ERIC Educational Resources Information Center

    Drummond, William E.

    1973-01-01

    Discusses current research in thermonuclear fusion with particular emphasis on the problem of confining hot plasma. Recent experiments indicate that magnetic bottles called tokamaks may achieve the necessary confinement times, and this break-through has given renewed optimism to the feasibility of commercial fusion power by the turn of the…

  1. Patterns of significant seismic quiescence on the Mexican Pacific coast

    NASA Astrophysics Data System (ADS)

    Muñoz-Diosdado, A.; Rudolf-Navarro, A. H.; Angulo-Brown, F.; Barrera-Ferrer, A. G.

    Many authors have proposed that the study of seismicity rates is an appropriate technique for evaluating how close a seismic gap may be to rupture. We designed an algorithm for identification of patterns of significant seismic quiescence by using the definition of seismic quiescence proposed by Schreider (1990). This algorithm shows the area of quiescence where an earthquake of great magnitude may probably occur. We have applied our algorithm to the earthquake catalog on the Mexican Pacific coast located between 14 and 21 degrees of North latitude and 94 and 106 degrees West longitude; with depths less than or equal to 60 km and magnitude greater than or equal to 4.3, which occurred from January, 1965 until December, 2014. We have found significant patterns of seismic quietude before the earthquakes of Oaxaca (November 1978, Mw = 7.8), Petatlán (March 1979, Mw = 7.6), Michoacán (September 1985, Mw = 8.0, and Mw = 7.6) and Colima (October 1995, Mw = 8.0). Fortunately, in this century earthquakes of great magnitude have not occurred in Mexico. However, we have identified well-defined seismic quiescences in the Guerrero seismic-gap, which are apparently correlated with the occurrence of silent earthquakes in 2002, 2006 and 2010 recently discovered by GPS technology.

  2. Magnitude Dependent Seismic Quiescence of 2008 Wenchuan Earthquake

    NASA Astrophysics Data System (ADS)

    Suyehiro, K.; Sacks, S. I.; Takanami, T.; Smith, D. E.; Rydelek, P. A.

    2014-12-01

    The change in seismicity leading to the Wenchuan Earthquake in 2008 (Mw 7.9) has been studied by various authors based on statistics and/or pattern recognitions (Huang, 2008; Yan et al., 2009; Chen and Wang, 2010; Yi et al., 2011). We show, in particular, that the magnitude-dependent seismic quiescence is observed for the Wenchuan earthquake and that it adds to other similar observations. Such studies on seismic quiescence prior to major earthquakes include 1982 Urakawa-Oki earthquake (M 7.1) (Taylor et al., 1992), 1994 Hokkaido-Toho-Oki earthquake (Mw=8.2) (Takanami et al., 1996), 2011 Tohoku earthquake (Mw=9.0) (Katsumata, 2011). Smith and Sacks (2013) proposed a magnitude-dependent quiescence based on a physical earthquake model (Rydelek and Sacks, 1995) and demonstrated the quiescence can be reproduced by the introduction of "asperities" (dilantacy hardened zones). Actual observations indicate the change occurs in a broader area than the eventual earthquake fault zone. In order to accept the explanation, we need to verify the model as the model predicts somewhat controversial features of earthquakes such as the magnitude dependent stress drop at lower magnitude range or the dynamically appearing asperities and repeating slips in some parts of the rupture zone. We show supportive observations. We will also need to verify the dilatancy diffusion to be taking place. So far, we only seem to have indirect evidences, which need to be more quantitatively substantiated.

  3. Precursory seismic quiescence: A preliminary assessment of the hypothesis

    USGS Publications Warehouse

    Reasenberg, P.A.; Matthews, M.V.

    1988-01-01

    Numerous cases of precursory seismic quiescence have been reported in recent years. Some investigators have interpreted these observations as evidence that seismic quiescence is a somewhat reliable precursor to moderate or large earthquakes. However, because failures of the pattern to predict earthquakes may not, in general, be reported, and because numerous earthquakes are not preceded by quiescence, the validity and reliability of the quiescence precursor have not been established. We have analyzed the seismicity rate prior to, and in the source region of, 37 shallow earthquakes (M 5.3-7.0) in central California and Japan for patterns of rate fluctuation, especially precursory quiescence. Nonuniformity in rate for these pre-mainshock sequences is relatively high, and numerous intervals with significant (p<0.10) extrema in rate are observed in some of the sequences. In other sequences, however, the rate remains within normal limits up to the time of the mainshock. Overall, in terms of an observational basis for intermediate-term earthquake prediction, no evidence is found in the cases studied for a systematic, widespread or reliable pattern of quiescence prior to the mainshocks. In earthquake sequences comprising full seismic cycles for 5 sets of (M 3.7-5.1) repeat earthquakes on the San Andreas fault near Bear Valley, California, the seismicity rates are found to be uniform. A composite of the estimated rate fluctuations for the sequences, normalized to the length of the seismic cycle, reveals a weak pattern of a low rate in the first third of the cycle, and a high rate in the last few months. While these observations are qualitative, they may represent weak expressions of physical processes occurring in the source region over the seismic cycle. Re-examination of seismicity rate fluctuations in volumes along the creeping section of the San Andreas fault specified by Wyss and Burford (1985) qualitatively confirms the existence of low-rate intervals in volumes 361

  4. Quantitative Mapping of Precursory Seismic Quiescence Before Large Aftershocks

    NASA Astrophysics Data System (ADS)

    Neukomm, S.; Wiemer, S.; Giardini, D.

    2002-12-01

    A relative decrease of aftershock activity before the occurrence of large aftershocks to M6+ mainshocks is one of only few earthquake precursors accepted for the IASPEI preliminary list of significant earthquake precursors. If one considers earthquake rate to be dependent on stressing rate, aftershocks sequences offer in fact an ideal environment to detect precursory quiescence before large earthquakes: The numerous aftershocks allow a much higher spatial and temporal resolution of transients in seismicity than possible with the average background rate of micro-earthquakes. Past studies of precursory quiescence before larger aftershocks, however, have largely been based on bulk value. The aim of this study is to map the temporal and spatial variability of activity rate within several rich aftershock sequences, and, possibly, exploit the results for improving real time probabilistic aftershock hazard assessment. We introduce a new algorithm based on fitting the modified Omori law to the aftershock sequences. At arbitrarily chosen grid points, the Omori parameters of the sub-samples containing all aftershock within 5 or 10 km of the node are estimated at time t. We calculate the number of aftershocks N +/- dN in the time interval t + dt using the relevant four Omori parameters (p, c and k) parameters and their corresponding standard deviations estimated using a bootstrap analysis. The difference between the forecasted and the observed number of aftershocks, normalized by the standard deviation of the forecast, is our estimator of rate change. The algorithm is tested on synthetic aftershock sequences containing artificial quiescences in order to calibrate the free parameters for optimal detection of precursory quiescence. We then perform our spatial and temporal mapping for several prominent Californian and Japanese aftershock sequences (Landers, Hector Mine, Northridge, Loma Prieta, Kobe, Western Tottori and Hokkaido). Preliminary results suggest that we cannot

  5. Immune quiescence: a model of protection against HIV infection.

    PubMed

    Card, Catherine M; Ball, Terry Blake; Fowke, Keith R

    2013-11-20

    Aberrant immune activation is a strong correlate of HIV disease progression, but little is known about how immune activation alters susceptibility to HIV infection. Susceptibility to HIV infection varies between individuals, but the immunological determinants of HIV transmission are not well understood. Here, we present evidence from studies of HIV transmission in the context of clinical trials and HIV-exposed seronegative (HESN) cohorts that implicates elevated immune activation as a risk factor for acquiring HIV. We propose a model of protection from infection based on a phenotype of low baseline immune activation referred to as immune quiescence. Immune quiescence is evidenced by reduced expression of T cell activation markers, low levels of generalized gene transcription and low levels of proinflammatory cytokine and chemokine production in the periphery and genital mucosa of HESN. Since HIV preferentially replicates in activated CD4+ T cells, immune quiescence may protect against infection by limiting HIV target cell availability. Although the determinants of immune quiescence are unclear, several potential factors have been identified that may be involved in driving this phenotype. HESN were shown to have elevated proportions of regulatory T cells (Tregs), which are known to suppress T cell activation. Likewise, proteins involved in controlling inflammation in the genital tract have been found to be elevated in HESN. Furthermore, expression of interferon regulatory factor 1 (IRF-1) is reduced in HESN as a consequence of genetic polymorphisms and differential epigenetic regulation. Since IRF-1 is an important regulator of immune responses, it may play a role in maintaining immune quiescence. Based on this model, we propose a novel avenue for HIV prevention targeted based on reducing host mucosal immune activation.

  6. S100B in myoblasts regulates the transition from activation to quiescence and from quiescence to activation and reduces apoptosis.

    PubMed

    Tubaro, Claudia; Arcuri, Cataldo; Giambanco, Ileana; Donato, Rosario

    2011-05-01

    S100B protein activates IKKβ/NF-κB within myoblasts, thereby inhibiting the expression of MyoD and the MyoD-downstream effectors, myogenin and p21(WAF1), and myoblast differentiation. Herein we show that myoblasts downregulate S100B expression once transferred from proliferation medium to differentiation medium via a p38 MAPK-driven transcriptional mechanism as well as a post-translational, proteasome-dependent mechanism, and that myoblasts that have not been committed to differentiation resume expressing S100B once transferred back to proliferation medium. Likewise, myoblasts downregulate S100B expression once transferred to quiescence medium, and interference with S100B downregulation as obtained by stable overexpression of the protein results in reduced acquisition of quiescence and a faster proliferation upon transfer of the cells from quiescence medium to proliferation medium, compared to controls. These latter effects are dependent on S100B-induced activation of JNK. Moreover, S100B reduces myoblast apoptosis in an MEK-ERK1/2, Akt, JNK, and NF-κB-dependent manner. However, myogenin(+) myoblasts (i.e., myocytes) and myotubes abundantly express S100B likely induced by myogenin. Our results suggest that (1) a timely repression of S100B expression is required for efficient myogenic differentiation; (2) S100B plays an important role in the expansion of the activated (i.e., proliferating) myoblast population; (3) under conditions associated with enhanced expression of S100B, the transition from proliferation to quiescence and from quiescence to proliferation might be altered; and (4) S100B exerts different regulatory effects in myoblasts and myocytes/myotubes/myofibers. This article is part of a Special Issue entitled: 11th European Symposium on Calcium. 2010 Elsevier B.V. All rights reserved.

  7. Cell-cycle quiescence maintains Caenorhabditis elegans germline stem cells independent of GLP-1/Notch.

    PubMed

    Seidel, Hannah S; Kimble, Judith

    2015-11-09

    Many types of adult stem cells exist in a state of cell-cycle quiescence, yet it has remained unclear whether quiescence plays a role in maintaining the stem cell fate. Here we establish the adult germline of Caenorhabditis elegans as a model for facultative stem cell quiescence. We find that mitotically dividing germ cells--including germline stem cells--become quiescent in the absence of food. This quiescence is characterized by a slowing of S phase, a block to M-phase entry, and the ability to re-enter M phase rapidly in response to re-feeding. Further, we demonstrate that cell-cycle quiescence alters the genetic requirements for stem cell maintenance: The signaling pathway required for stem cell maintenance under fed conditions--GLP-1/Notch signaling--becomes dispensable under conditions of quiescence. Thus, cell-cycle quiescence can itself maintain stem cells, independent of the signaling pathway otherwise essential for such maintenance.

  8. The mysteries of restless legs syndrome.

    PubMed

    Martin, Caren McHenry

    2007-11-01

    Restless legs syndrome (RLS) is a sensorimotor disorder characterized by the uncontrollable urge to move the legs. This urge can often be accompanied by pain or other unpleasant sensations, and it either occurs or worsens with rest. Affecting an estimated 6% to 15% of the adult population, RLS compromises the patient's ability to sleep and can significantly decrease quality of life. Because diagnosis currently relies solely on patient (or caregiver) interview, recognizing the symptoms of RLS and knowing what medications treat this condition--as well as the many that exacerbate it--is important for all health care practitioners.

  9. Myoclonus in familial restless legs syndrome.

    PubMed

    Boghen, D; Peyronnard, J M

    1976-05-01

    Eighteen members of a family were affected over a span of five generations with the restless legs syndrome, transmitted as an autosomal dominant trait. Ten patients had myoclonus. The propositus, a 57-year-old man, suffered from repeated, intense, asymmetric flexion jerks of the lower extremities, alternating with fidgeting and friction movements of the legs; all occurred at night prior to sleep and severely interfering with it. The patient's movements ceased with the onset of stage 1 sleep, while in his brother, the motor activity persisted in stages 1 and 2 of sleep.

  10. The Molecular Genetics of Restless Legs Syndrome.

    PubMed

    Rye, David B

    2015-09-01

    Restless legs syndrome (RLS) is a common sensorimotor trait defined by symptoms that interfere with sleep onset and maintenance in a clinically meaningful way. Nonvolitional myoclonus while awake and asleep is a sign of the disorder and an informative endophenotype. The genetic contributions to RLS/periodic leg movements are substantial, are among the most robust defined to date for a common disease, and account for much of the variance in disease expressivity. The disorder is polygenic, as revealed by recent genome-wide association studies. Experimental studies are revealing mechanistic details of how these common variants might influence RLS expressivity. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Sonoluminescence, shock waves, and micro-thermonuclear fusion

    SciTech Connect

    Moss, W.C.; Clarke, D.B.; White, J.W.; Young, D.A.

    1995-08-01

    We have performed numerical hydrodynamic simulations of the growth and collapse of a sonoluminescing bubble in a liquid. Our calculations show that spherically converging shock waves are generated during the collapse of the bubble. The combination of the shock waves and a realistic equation of state for the gas in the bubble provides an explanation for the measured picosecond optical pulse widths and indicates that the temperatures near the center of the bubble may exceed 3O eV. This leads naturally to speculation about obtaining micro-thermonuclear fusion in a bubble filled with deuterium (D{sub 2}) gas. Consequently, we performed numerical simulations of the collapse of a D{sub 2} bubble in D{sub 2}0. A pressure spike added to the periodic driving amplitude creates temperatures that may be sufficient to generate a very small, but measurable number of thermonuclear D-D fusion reactions in the bubble.

  12. Atypical Thermonuclear Supernovae from Tidally Crushed White Dwarfs

    SciTech Connect

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2008-01-01

    Suggestive evidence has accumulated that intermediate mass black holes (IMBHs) exist in some globular clusters. Some stars will inevitably wander sufficiently close to the hole to suffer a tidal disruption. IMBHs can disrupt not only solar-type stars but also compact white dwarf stars. We investigate the fate of white dwarfs that approach the hole close enough to be disrupted and compressed to such an extent that explosive nuclear burning is triggered. Based on a precise modeling of the gas dynamics together with the nuclear reactions, it is argued that thermonuclear ignition is a natural outcome for white dwarfs of all masses passing well within the tidal radius. A good fraction of the star is accreted, yielding high luminosities that persist for up to a year. A peculiar, underluminous thermonuclear explosion accompanied by a soft X-ray transient signal would, if detected, be a compelling testimony for the presence of an IMBH.

  13. Thermonuclear Burning as a Probe of Neutron Star

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod

    2008-01-01

    Thermonuclear fusion is a fundamental process taking place in the matter transferred onto neutron stars in accreting binary systems. The heat deposited by nuclear reactions becomes readily visible in the X-ray band when the burning is either unstable or marginally stable, and results in the rich phenomenology of X-ray bursts, superbursts, and mHz quasiperiodic oscillations. Fast X-ray timing observations with NASA's Rossi X-ray Timing Explorer (RXTE) over the past decade have revealed a wealth of new phenomena associated with thermonuclear burning on neutron stars, including the discovery of nuclear powered pulsations during X-ray bursts and superbursts. I will briefly review our current observational and theoretical understanding of these new phenomena, with an emphasis on recent findings, and discuss what they are telling us about the structure of neutron stars.

  14. Parameters of the focusing optics in a laser thermonuclear reactor

    SciTech Connect

    Basov, N.G.; Belousov, N.I.; Vergunova, G.A.; Grishunin, P.A.; Danilov, A.E.; Lebo, I.G.; Rozanov, V.B.; Sklizkov, G.V.; Subbotin, V.I.; Fedotov, S.I.

    1985-03-01

    The energy balance of a laser thermonuclear reactor is considered and it is shown that the energy of the reaction products absorbed by the focusing optics of the reactor considerably exceeds the energy absorbed from the laser pulse. The x-ray spectrum of the target emission is calculated and used to find the minimum distances from the center of the chamber to the optical system. Variants of the gas shield are analyzed. The laser radiation brightness required to ignite the reaction is used to obtain a relationship between the minimum focal length and the optical strength of the material employed for the optics. It is shown that thermonuclear neutrons incident on the focusing system generate considerable thermal stresses and deformations.

  15. Thermonuclear Burning as a Probe of Neutron Star

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod

    2008-01-01

    Thermonuclear fusion is a fundamental process taking place in the matter transferred onto neutron stars in accreting binary systems. The heat deposited by nuclear reactions becomes readily visible in the X-ray band when the burning is either unstable or marginally stable, and results in the rich phenomenology of X-ray bursts, superbursts, and mHz quasiperiodic oscillations. Fast X-ray timing observations with NASA's Rossi X-ray Timing Explorer (RXTE) over the past decade have revealed a wealth of new phenomena associated with thermonuclear burning on neutron stars, including the discovery of nuclear powered pulsations during X-ray bursts and superbursts. I will briefly review our current observational and theoretical understanding of these new phenomena, with an emphasis on recent findings, and discuss what they are telling us about the structure of neutron stars.

  16. Shock ignition of thermonuclear fuel with high areal density.

    PubMed

    Betti, R; Zhou, C D; Anderson, K S; Perkins, L J; Theobald, W; Solodov, A A

    2007-04-13

    A novel method by C. Zhou and R. Betti [Bull. Am. Phys. Soc. 50, 140 (2005)] to assemble and ignite thermonuclear fuel is presented. Massive cryogenic shells are first imploded by direct laser light with a low implosion velocity and on a low adiabat leading to fuel assemblies with large areal densities. The assembled fuel is ignited from a central hot spot heated by the collision of a spherically convergent ignitor shock and the return shock. The resulting fuel assembly features a hot-spot pressure greater than the surrounding dense fuel pressure. Such a nonisobaric assembly requires a lower energy threshold for ignition than the conventional isobaric one. The ignitor shock can be launched by a spike in the laser power or by particle beams. The thermonuclear gain can be significantly larger than in conventional isobaric ignition for equal driver energy.

  17. Strong plasma screening in thermonuclear reactions: Electron drop model

    NASA Astrophysics Data System (ADS)

    Kravchuk, P. A.; Yakovlev, D. G.

    2014-01-01

    We analyze enhancement of thermonuclear fusion reactions due to strong plasma screening in dense matter using a simple electron drop model. In the model we assume fusion in a potential that is screened by an effective electron cloud around colliding nuclei (extended Salpeter ion-sphere model). We calculate the mean-field screened Coulomb potentials for atomic nuclei with equal and nonequal charges, appropriate astrophysical S factors, and enhancement factors of reaction rates. As a byproduct, we study the analytic behavior of the screening potential at small separations between the reactants. In this model, astrophysical S factors depend not only on nuclear physics but on plasma screening as well. The enhancement factors are in good agreement with calculations by other methods. This allows us to formulate a combined, pure analytic model of strong plasma screening in thermonuclear reactions. The results can be useful for simulating nuclear burning in white dwarfs and neutron stars.

  18. Enhancement of thermonuclear reaction rates in extremely dense stellar plasmas

    NASA Astrophysics Data System (ADS)

    Itoh, Naoki; Kuwashima, Fumiyoshi; Munakata, Hiroharu

    1990-10-01

    The enhancement factor of the thermonuclear reaction rates is calculated for the extremely dense stellar plasmas in the liquid phase where the condition 3Gamma/tau less than or equal to 1.6 is not necessarily imposed. Here the parameter 3Gamma/tau corresponds to the ratio of the classical turning point radius at the Gamow peak and the mean interionic distance in the case of the pure Coulomb potential. Direct double integration is carried out to obtain the thermonuclear reaction rates. The result is presented in the form of an analytic fitting formula to facilitate applications. The present fitting formula is valid for 3Gamma/tau = 0-5.4. The present calculation is intended to serve as the best available one for the case that ions are in the semiquantum regime.

  19. Method of achieving the controlled release of thermonuclear energy

    DOEpatents

    Brueckner, Keith A.

    1986-01-01

    A method of achieving the controlled release of thermonuclear energy by illuminating a minute, solid density, hollow shell of a mixture of material such as deuterium and tritium with a high intensity, uniformly converging laser wave to effect an extremely rapid build-up of energy in inwardly traveling shock waves to implode the shell creating thermonuclear conditions causing a reaction of deuterons and tritons and a resultant high energy thermonuclear burn. Utilizing the resulting energy as a thermal source and to breed tritium or plutonium. The invention also contemplates a laser source wherein the flux level is increased with time to reduce the initial shock heating of fuel and provide maximum compression after implosion; and, in addition, computations and an equation are provided to enable the selection of a design having a high degree of stability and a dependable fusion performance by establishing a proper relationship between the laser energy input and the size and character of the selected material for the fusion capsule.

  20. Predisposing factors of restless legs syndrome in pregnancy.

    PubMed

    Tunç, Tuğba; Karadağ, Yeşim Sücüllü; Doğulu, Funda; Inan, Levent E

    2007-04-15

    The occurrence of restless legs syndrome in pregnancy is well known. However, the mechanism of this association is unclear. In this study, we aimed to identify the factors that predispose women to have restless legs syndrome during pregnancy. A total of 146 pregnant women were included in the study. Patients were asked questions regarding demographic characteristics, complications of pregnancy, medical therapy (vitamin and iron intake), sleep disorders, muscle cramps, and excessive daytime sleepiness. Electroneurography, routine blood biochemistry tests, complete blood count, and thyroid function tests were performed and vitamin B12, folic acid, serum iron, iron-binding capacity, ferritin, iron saturation, prolactin, estradiol, and progesterone were measured. Of the participants, 38 were diagnosed as having restless legs syndrome. In women with restless legs syndrome, additional medical problems, night cramps, and excessive daytime sleepiness were more frequent. In women without restless legs syndrome, serum hemoglobin levels were significantly higher and the use of supplemental iron or vitamins was greater. Among the women with restless legs syndrome, progesterone levels were slightly higher but this difference was not statistically significant. In summary, in this study, lower hemoglobin levels and supplementation deficits of iron and vitamins were found be the risk factors for restless legs syndrome in pregnancy.

  1. Pramipexole Alters Thermoregulation in Restless Legs Syndrome

    PubMed Central

    Salminen, Aaro V.; Rimpilä, Ville; Polo, Olli

    2014-01-01

    Study Objectives: Previous studies have associated restless legs syndrome (RLS) with peripheral hypoxia and impaired thermoregulation in the lower extremities. We performed long-term monitoring of skin temperatures in order to investigate whether these findings could be explained by reduced blood flow to the peripheral tissues. Methods: 96-hour continuous measurements of skin temperature were performed both in the distal and proximal parts of the body of 15 patients with RLS and 14 healthy controls. During the recording, the patients participated in suggested immobilization tests both with and without pramipexole medication. Results: We found no baseline differences in distal or proximal skin temperature between patients and controls in daytime or during immobilization. However, pramipexole significantly increased distal skin temperature in the patient group during immobilization (31.1°C vs. 32.9°C, p < 0.05). Daytime temperatures were not affected by therapy or disease status. Conclusions: The data suggest that patients with RLS and healthy controls have similar blood flow to the peripheral skin tissue. Pramipexole, however, alters thermoregulation and the previous studies might have been biased by medication. Dopaminergic medication is a major confounding factor when assessing peripheral phenomena in RLS and should be controlled for in the future studies. Citation: Salminen AV, Rimpilä V, Polo O. Pramipexole alters thermoregulation in restless legs syndrome. J Clin Sleep Med 2014;10(12):1325-1329. PMID:25325594

  2. Olanzapine-induced restless legs syndrome.

    PubMed

    Zhao, Mangsuo; Geng, Tongchao; Qiao, Liyan; Zhang, Mingjie; Shi, Jie; Huang, Fangjie; Lin, Xianzhong; Wang, Jing; Zuo, Huancong

    2014-09-01

    Only nine patients with olanzapine-induced restless legs syndrome (RLS) have been reported in the literature to our knowledge. We describe two patients with olanzapine-induced RLS treated at our hospital and review the nine reported patients. There were five women and six men aged between 28 and 62 years in the overall group. RLS symptoms emerged at olanzapine doses between 2.5 and 20mg. The symptoms improved in all patients when the dose was reduced and immediately disappeared when the medication was stopped. International Restless Legs Scale (IRLS) scores ranged from 10 to 35. Three patients had a family history of idiopathic RLS. Supplemental drugs were administered to control RLS symptoms in five patients. Ropinirole was effective in one patient, while two patients did not respond to the drug. Propoxyphene effectively relieved symptoms in one patient who did not respond to ropinirole or clonazepam. RLS symptoms did not recur following substitution of other antipsychotic drugs for olanzapine. In conclusion, olanzapine can induce RLS, particularly in patients with a family history of idiopathic RLS. More than half of the patients experienced severe to very severe symptoms. A dose-dependent relationship was observed between olanzapine and RLS symptoms. A gradual increase in dose may prevent olanzapine-induced RLS. The optimal treatment for olanzapine-induced RLS is discontinuation of olanzapine. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Purinergic Receptors in Quiescence and Localization of Leukemic Stem Cells

    DTIC Science & Technology

    2011-05-01

    2011. Ewing’s Sarcoma Gene EWS regulates Hematopoietic Stem Cell Senescence. Blood, 117:1156-66. Conclusion How leukemia stem cells gained...findings contained in this report are those of the author( s ) and should not be construed as an official Department of the Army position, policy or...Receptors in Quiescence and Localization of Leukemic Stem Cells 5b. GRANT NUMBER W81XWH-09-1-0364 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d

  4. Hypoxia, MTOR and autophagy: converging on senescence or quiescence.

    PubMed

    Blagosklonny, Mikhail V

    2013-02-01

    Although hypoxia can cause cell cycle arrest, it may simultaneously suppress a conversion from this arrest to senescence. Furthermore, hypoxia can suppress senescence caused by diverse stimuli, maintaining reversible quiescence instead. Hypoxia activates autophagy and inhibits MTOR, thus also activating autophagy. What is the relationship between autophagy and cellular senescence? Also, can inhibition of MTOR and stimulation of autophagy explain the gerosuppressive effects of hypoxia?

  5. Proteasome dynamics between proliferation and quiescence stages of Saccharomyces cerevisiae.

    PubMed

    Yedidi, Ravikiran S; Fatehi, Amatullah K; Enenkel, Cordula

    The ubiquitin-proteasome system (UPS) plays a critical role in cellular protein homeostasis and is required for the turnover of short-lived and unwanted proteins, which are targeted by poly-ubiquitination for degradation. Proteasome is the key protease of UPS and consists of multiple subunits, which are organized into a catalytic core particle (CP) and a regulatory particle (RP). In Saccharomyces cerevisiae, proteasome holo-enzymes are engaged in degrading poly-ubiquitinated substrates and are mostly localized in the nucleus during cell proliferation. While in quiescence, the RP and CP are sequestered into motile and reversible storage granules in the cytoplasm, called proteasome storage granules (PSGs). The reversible nature of PSGs allows the proteasomes to be transported back into the nucleus upon exit from quiescence. Nuclear import of RP and CP through nuclear pores occurs via the canonical pathway that includes the importin-αβ heterodimer and takes advantage of the Ran-GTP gradient across the nuclear membrane. Dependent on the growth stage, either inactive precursor complexes or mature holo-enzymes are imported into the nucleus. The present review discusses the dynamics of proteasomes including their assembly, nucleo-cytoplasmic transport during proliferation and the sequestration of proteasomes into PSGs during quiescence. [Formula: see text].

  6. Possibilities of applications of fiber Bragg gratings for thermonuclear fusion technology

    NASA Astrophysics Data System (ADS)

    Gasior, P.

    2016-09-01

    The research on harnessing thermonuclear fusion is considered to be important for reaching global energetic safety as the future thermonuclear fusion reactors offer an inexhaustible and CO2 emission free source of electric power. The development of thermonuclear fusion reactors is a great interdisciplinary effort which needs participation of scientists dealing with many fields of physics and engineering. Due to the experimental character of the works (the best example is the effort for the development of ITER - International Thermonuclear Experimental Reactor) its crucial part is in the design and application of diagnostics operating in harsh thermonuclear environments. Fiber optics and especially fiber Bragg gratings are components which can operate feasibly in both irradiation and electromagnetic interference conditions. This paper is to give a prospect of application of fiber Bragg grating sensors in devices aimed on the research in the thermonuclear fusion field.

  7. Thermonuclear milestones: (2) Beginnings of the Soviet H-bomb program

    SciTech Connect

    Goncharov, G.A.

    1996-11-01

    Early Soviet theoretical work on thermonuclear ignition was adied by espionage, but many important ideas were conceived and developed independently {copyright} {ital 1996 American Institute of Physics.}

  8. Restless Legs Syndrome -- Self-Tests and Diagnosis

    MedlinePlus

    ... Treatment Jet Lag Overview Symptoms & Self Test Treatment Narcolepsy Overview & Facts Symptoms Self-Tests & Diagnosis Treatment Restless ... Category Insomnias Insomnia Child Insomnia Short Sleeper Hypersomnias Narcolepsy Insufficient Sleep Syndrome Long Sleeper Sleep Breathing Disorders ...

  9. Odd-skipped related 2 is epigenetically regulated in cellular quiescence

    SciTech Connect

    Kawai, Shinji; Amano, Atsuo

    2010-06-11

    Cellular behavior and development are extensively altered during the transition from cell cycle into quiescence, though the mechanism involved in establishing and maintaining quiescence is largely unknown. We found that Odd-skipped related 2 (Osr2) was up-regulated during cellular quiescence by serum starvation as well as culturing to confluence. To investigate the regulatory mechanism of Osr2 under these conditions, we characterized the mouse Osr2 promoter. CpG islands in the flanking region of the transcription start site were predominantly methylated in exponentially growing cells, resulting in silencing of Osr2 expression. In addition, CpG demethylation in quiescence caused activation of Osr2 expression, while acetylation of the H3 and H4 histones during quiescence also led to an increase in Osr2 expression. These results suggest that epigenetically regulated Osr2 plays an important role in cellular quiescence and proliferation.

  10. Restless Leg Syndrome/Willis-Ekbom Disease Pathophysiology.

    PubMed

    Allen, Richard P

    2015-09-01

    Restless leg syndrome/Willis-Ekbom disease has brain iron deficiency that produces excessive dopamine and known genetic risks, some of which contribute to the brain iron deficiency. Dopamine treatments work temporarily but may eventually produce further postsynaptic down-regulation and worse restless leg syndrome. This article includes sections focused on pathophysiologic findings from each of these areas: genetics, cortical-spinal excitability, and iron and dopamine. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Association of Restless Legs Syndrome Variants in Korean Patients with Restless Legs Syndrome

    PubMed Central

    Kim, Myeong-Kyu; Cho, Yong Won; Shin, Won Chul; Cho, Jae Wook; Shon, Young Min; Kim, Jee Hyun; Yang, Kwang Ik; Earley, Christopher J.; Allen, Richard P.

    2013-01-01

    Study Objectives: Recent genome-wide association studies (GWAS) for Caucasians identified several allelic variants associated with increased risk of developing restless legs syndrome (RLS), also known as Willis-Ekbom disease. Although the pathogenic mechanisms of RLS are not entirely understood, it is becoming increasingly evident that many diseases such as RLS can be attributed to an epistasis. The study objectives were to evaluate whether the associations of RLS with all loci determined in previous GWAS for Caucasians can be replicated significantly for the Korean population and to elucidate whether an epistasis plays a role in the pathogenesis of RLS. Design, Setting, and Participants: DNA from 320 patients with RLS and 320 age- and sex-matched controls were genotyped for variants in the RLS loci. Measurements and Results: A significant association was found for rs3923809 and rs9296249 in BTBD9 (P < 0.0001 and P = 0.001, respectively); the odds ratio (OR) for rs3923809 was 1.61 (P < 0.0001) to 1.88 (P < 0.0001) and the OR for rs9296249 was 1.44 (P = 0.001) to 1.73 (P = 0.002), according to the model of inheritance. The OR for the interaction between rs3923809 in BTBD9 and rs4626664 in PTPRD was 2.05 (P < 0.0001) in the additive model, 1.80 (P = 0.002) in the dominant model and 2.47 (P = 0.004) in the recessive model. There was no significant association between genotypes of all tested single nucleotide polymorphisms and the mean value of serum iron parameters. Conclusions: Our results suggest that the role of BTBD9 in the pathogenesis of restless legs syndrome is more universal across populations than previously reported and more efforts should be focused on the role of epistasis in the genetic architecture of restless legs syndrome. Citation: Kim MK; Cho YW; Shin WC; Cho JW; Shon YM; Kim JH; Yang KI; Earley CJ; Allen RP. Association of restless legs syndrome variants in Korean patients with restless legs syndrome. SLEEP 2013;36(12):1787-1791. PMID:24293752

  12. Clinical correlates of the restless legs syndrome.

    PubMed

    Marin, Luis Fabiano; Felicio, Andre Carvalho; Santos, William Adolfo; Prado, Lucila Bizari; Prado, Gilmar Fernandes

    2012-07-01

    To determine the clinical correlates of the restless legs syndrome (RLS) in a Brazilian sleep disorders center. We retrospectively studied 118 patients with RLS from January, 2004, to December, 2010. The analyzed variables were: age at disease onset, gender, race, years of school instruction, primary and secondary RLS, and treatment options. Among the studied patients, 83.9% were women with a female/male sex ratio of 5:1. Mean age of the patients at symptom onset ± standard deviation was 41.7±17.9 years-old. The primary RLS was found in 85% of patients. The other 15% remainders consisted of secondary forms, and they were associated with neuropathy, iron deficiency anemia, end-stage renal disease, or Parkinson's disease. Drug therapy for RLS was introduced in 67% of patients. Most patients presented primary RLS with an early disease onset. Further epidemiological studies are welcomed to provide better information on secondary RLS in Brazil.

  13. Serum 25-hydroxyvitamin D levels in restless legs syndrome patients.

    PubMed

    Balaban, Hatice; Yıldız, Özlem Kayım; Çil, Gülsüm; Şentürk, İlteriş Ahmet; Erselcan, Taner; Bolayır, Ertuğrul; Topaktaş, Suat

    2012-08-01

    Restless legs syndrome is characterised by discomfort during rest and an urge to move the limbs that is accompanied by abnormal sensations. Studies on disease pathophysiology have focused on dopaminergic dysfunction. Vitamin D may play an important role in dopamine function, but the role of vitamin D in restless legs syndrome has not been examined. We compared the serum vitamin D levels of RLS patients and matched controls and explored the correlation of plasma vitamin D levels with disease severity. We measured serum 25-hydroxyvitamin D levels in 36 patients with restless legs syndrome and compared them to 38 healthy control subjects. The mean serum 25-hydroxyvitamin D levels were 7.31±4.63 ng/mL in female patients with restless legs syndrome and 12.31±5.27 ng/mL in female control subjects (p=0.001). We found a significant inverse correlation between vitamin D levels and disease severity in females (p=0.01, r=-0.47). The mean serum vitamin D levels were lower in female patients with restless legs syndrome. Low vitamin D levels may cause dopaminergic dysfunction in restless legs syndrome patients. Further studies are required to confirm these results. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Restless leg syndrome: a neglected diagnosis.

    PubMed

    Einollahi, Behzad; Izadianmehr, Neda

    2014-09-01

    Restless legs syndrome (RLS) is an irresistible urge to move legs that usually occur during inactivity and at night. This neurologic condition is associated with increased risk of nocturnal hypertension as well as cardiovascular events and affects patient's sleep, which leads to anxiety, depression, and decreases quality of life. Presence of RLS in patients on hemodialysis is associated with higher mortality rate. Most of the times, patients have indescribable symptoms. The aim of this review was to provide physicians with information to be aware and turn their attention to the patient's symptoms, which are the most important clue to diagnosis of RLS. For data extraction, we reviewed PubMed, Scopus, Google scholar, the Cochrane collaboration, and Up to Date databases with the keywords of restless legs syndrome, sleep disorders, and end-stage renal disease (ESRD). The most recent review articles, clinical trials, and cross-sectional studies with large sample sizes that had used International RLS Study Group criteria (IRLSSG) and had focused on demographic characteristics and renal function were included. This situation has described in primary and secondary forms. The former usually occurs in younger patients and seems to have genetic tendencies and the latter is due to the iron deficiency state, pregnancy, and ESRD. Two major theories are developed regarding the pathophysiology of RLS. The first one concerns central nervous system dopamine imbalance and the second one concerns intracellular iron dysregulation. The most common used pharmacologic agents in treatment of RLS are dopamine agonists. Other used therapeutic agents include levodopa, Alpha-2-delta calcium channel ligands, opioids, anticonvulsants, benzodiazepines, clonidine, iron therapy in low levels of serum ferritin, and nonpharmacologic therapies. The most important factor in diagnosis is physician's attention and clinical experience with this condition and using IRLSSG.

  15. Restless Leg Syndrome: A Neglected Diagnosis

    PubMed Central

    Einollahi, Behzad; Izadianmehr, Neda

    2014-01-01

    Context: Restless legs syndrome (RLS) is an irresistible urge to move legs that usually occur during inactivity and at night. This neurologic condition is associated with increased risk of nocturnal hypertension as well as cardiovascular events and affects patient’s sleep, which leads to anxiety, depression, and decreases quality of life. Presence of RLS in patients on hemodialysis is associated with higher mortality rate. Most of the times, patients have indescribable symptoms. The aim of this review was to provide physicians with information to be aware and turn their attention to the patient’s symptoms, which are the most important clue to diagnosis of RLS. Evidence Acquisition: For data extraction, we reviewed PubMed, Scopus, Google scholar, the Cochrane collaboration, and Up to Date databases with the keywords of restless legs syndrome, sleep disorders, and end-stage renal disease (ESRD). The most recent review articles, clinical trials, and cross-sectional studies with large sample sizes that had used International RLS Study Group criteria (IRLSSG) and had focused on demographic characteristics and renal function were included. This situation has described in primary and secondary forms. The former usually occurs in younger patients and seems to have genetic tendencies and the latter is due to the iron deficiency state, pregnancy, and ESRD. Results: Two major theories are developed regarding the pathophysiology of RLS. The first one concerns central nervous system dopamine imbalance and the second one concerns intracellular iron dysregulation. The most common used pharmacologic agents in treatment of RLS are dopamine agonists. Other used therapeutic agents include levodopa, Alpha-2-delta calcium channel ligands, opioids, anticonvulsants, benzodiazepines, clonidine, iron therapy in low levels of serum ferritin, and nonpharmacologic therapies. Conclusions: The most important factor in diagnosis is physician’s attention and clinical experience with this

  16. Restless legs syndrome in patients on hemodialysis.

    PubMed

    Salman, Saleh Mohammad Yaser

    2011-03-01

    Restless legs syndrome (RLS) is common among dialysis patients, with a reported prevalence of 6-60%. The prevalence of RLS in Syrian patients on hemodialysis (HD) is not known. The purpose of this study is to determine the prevalence of RLS in patients on regular HD, and to find the possible correlation between the presence of RLS and demographic, clinical, and biochemical factors. One hundred and twenty-three patients (male/female = 70/53, mean age = 41.95 ± 15.11 years) on HD therapy at the Aleppo University Hospital were enrolled into the study. RLS was diagnosed based on criteria established by the International Restless Legs Syn-drome Study Group (IRLSSG). Data procured were compared between patients with and without RLS. Applying the IRLSSG criteria for the diagnosis, RLS was seen in 20.3% of the study pa-tients. No significant difference in age, gender, and intake of nicotine and caffeine was found between patients with and without the RLS. Similarly, there was no difference between the two groups in the duration of end-stage renal disease (ESRD), the period of dialysis dependence, dialysis adequacy, urea and creatinine levels, and the presence of anemia. The co-morbidities and the use of drugs also did not differ in the two groups. Our study suggests that the high prevalence of RLS among patients on HD requires careful attention and correct diagnosis can lead to better therapy and better quality of life. The pathogenesis of RLS is not clear and further studies are required to identify any possible cause as well as to discover the impact of this syndrome on sleep, quality of life, and possibly other complications such as cardiovasculare disease.

  17. D-ribose benefits restless legs syndrome.

    PubMed

    Shecterle, Linda; Kasubick, Robert; St Cyr, John

    2008-11-01

    Restless legs syndrome is a neurological disorder characterized by unpleasant sensations and pain, predominantly in the lower extremities while at rest, accompanied by an uncontrollable urge for movement for relief. We report on two affected male individuals, a father and son, ages 71 and 47, from a family in which three generations carry the diagnosis. To evaluate any potential benefit of D-ribose in this condition, each individual orally consumed 5-g doses of D-ribose daily at different trial stages. Each stage lasted 3 weeks with a 2-week washout period between stages. The initial stage involved a single 5 gm dose of D-ribose consumed at breakfast. Throughout the second stage, D-ribose was taken at breakfast and lunch. In the third stage, D-ribose was taken at all meals, breakfast, lunch, and dinner. Diaries by the subjects pertaining to their documentation and severity of restless legs syndrome symptoms was compiled. During the initial stage both men reported a general feeling of more energy and less fatigue, most notably after exercise, without any significant changes in their symptoms. With the increase in the daily dose of D-ribose, in the second stage, their leg twitching and the feeling to move during the day was reduced for 1 subject, and rarely present in the other. Both still experienced the unpleasant sensations during the night. However, during the final stage, a further increase in the daily dose of D-ribose eliminated their daily symptoms and the symptoms at night were of a lesser degree and had a later occurrence. Both men reported that D-ribose did not totally eliminate their discomfort, but the severity and onset of symptoms affecting their quality of life was substantially improved with D-ribose without any adverse reactions.

  18. Thermonuclear runaways in thick hydrogen rich envelopes of neutron stars

    NASA Technical Reports Server (NTRS)

    Starrfield, S. G.; Kenyon, S.; Truran, J. W.; Sparks, W. M.

    1981-01-01

    A Lagrangian, fully implicit, one dimensional hydrodynamic computer code was used to evolve thermonuclear runaways in the accreted hydrogen rich envelopes of 1.0 Msub solar neutron stars with radii of 10 km and 20 km. Simulations produce outbursts which last from about 750 seconds to about one week. Peak effective temeratures and luninosities were 26 million K and 80 thousand Lsub solar for the 10 km study and 5.3 millison and 600 Lsub solar for the 20 km study. Hydrodynamic expansion on the 10 km neutron star produced a precursor lasting about one ten thousandth seconds.

  19. Is restlessness best understood as a process? Reflecting on four boys’ restlessness during music therapy in kindergarten

    PubMed Central

    Helle-Valle, Anna; Binder, Per-Einar; Anderssen, Norman; Stige, Brynjulf

    2017-01-01

    ABSTRACT ADHD can be considered an internationally recognized framework for understanding children’s restlessness. In this context, children’s restlessness is understood as a symptom of neurodevelopmental disorder. However, there are other possible understandings of children’s restlessness. In this article, we explore four boys’ collaborative and creative process as it is described and understood by three adults. The process is framed by a community music therapy project in a Norwegian kindergarten, and we describe four interrelated phases of this process: Exploring musical vitality and cooperation, Consolidating positions, Performing together, and Discovering ripple effects. We discuss these results in relation to seven qualities central to a community music therapy approach: participation, resource orientation, ecology, performance, activism, reflexivity and ethics. We argue that in contrast to a diagnostic approach that entails a focus on individual problems, a community music therapy approach can shed light on adult and systemic contributions to children’s restlessness. PMID:28532331

  20. Concise Review: Quiescence in Adult Stem Cells: Biological Significance and Relevance to Tissue Regeneration.

    PubMed

    Rumman, Mohammad; Dhawan, Jyotsna; Kassem, Moustapha

    2015-10-01

    Adult stem cells (ASCs) are tissue resident stem cells responsible for tissue homeostasis and regeneration following injury. In uninjured tissues, ASCs exist in a nonproliferating, reversibly cell cycle-arrested state known as quiescence or G0. A key function of the quiescent state is to preserve stemness in ASCs by preventing precocious differentiation, and thus maintaining a pool of undifferentiated ASCs. Recent evidences suggest that quiescence is an actively maintained state and that excessive or defective quiescence may lead to compromised tissue regeneration or tumorigenesis. The aim of this review is to provide an update regarding the biological mechanisms of ASC quiescence and their role in tissue regeneration.

  1. Thermonuclear Supernova Explosions From Hybrid White Dwarf Progenitors

    NASA Astrophysics Data System (ADS)

    Willcox, Donald E.; Townsley, Dean; Calder, Alan; Denissenkov, Pavel; Herwig, Falk

    2016-01-01

    Motivated by recent results in stellar evolution in which convective boundary mixing in SAGB stars can give rise to hybrid white dwarf (WD) stars with a C-O core inside an O-Ne shell, we simulate thermonuclear (Type Ia) supernovae from these hybrid progenitors. We use the FLASH code to perform multidimensional simulations in the deflagration to detonation transition (DDT) explosion paradigm from progenitor models produced with the MESA stellar evolution code that include the thermal energetics of the Urca process. We performed a suite of DDT simulations over a range of ignition conditions and compare to previous results from a suite of C-O white dwarfs. Despite significant variability within each suite, distinguishing trends are apparent in their Ni-56 yields and the kinetic properties of their ejecta. We comment on the feasibility of these hybrid WD explosions as the source of some classes of observed subluminous events. This research was supported in part by the U.S. Department of Energy under grant DE-FG02-87ER40317 and by resources at the Institute for Advanced Computational Science at Stony Brook University. The software used in this work was in part developed by the DOE-supported ASC/Alliances Center for Astrophysical Thermonuclear Flashes at the University of Chicago.

  2. The classification of magnetohydrodynamic regimes of thermonuclear combustion

    SciTech Connect

    Remming, Ian S.; Khokhlov, Alexei M.

    2014-10-10

    Physical properties of magnetohydrodynamic (MHD) reaction fronts are studied as functions of the thermodynamic conditions, and the strength and orientation of the magnetic field in the unburned matter through which the fronts propagate. We determine the conditions for the existence of the various types of MHD reaction fronts and the character of the changes in physical quantities across these reaction fronts. The analysis is carried out in general for a perfect gas equation of state and a constant energy release, and then extended to thermonuclear reaction fronts in degenerate carbon-oxygen mixtures and degenerate helium in conditions typical of Type Ia supernova explosions. We find that as unburned matter enters perpendicular to a reaction front, the release of energy through burning generates shear velocity in the reacting gas that, depending on the type of reaction front, strengthens or weakens the magnetic field. In addition, we find that the steady-state propagation of a reaction front is impossible for certain ranges of magnetic field direction. Our results provide insight into the phenomena of MHD thermonuclear combustion that is relevant to the interpretation of future simulations of SN Ia explosions that have magnetic fields systematically incorporated.

  3. Thermonuclear supernova models, and observations of Type Ia supernovae

    SciTech Connect

    Bravo, E.; Garcia-Senz, D.; Badenes, C.

    2005-10-21

    In this paper, we review the present state of theoretical models of thermonuclear supernovae, and compare their predictions with the constraints derived from observations of Type Ia supernovae. The diversity of explosion mechanisms usually found in one-dimensional simulations is a direct consequence of the impossibility to resolve the flame structure under the assumption of spherical symmetry. Spherically symmetric models have been successful in explaining many of the observational features of Type Ia supernovae, but they rely on two kinds of empirical models: one that describes the behaviour of the flame on the scales unresolved by the code, and another that takes account of the evolution of the flame shape. In contrast, three-dimensional simulations are able to compute the flame shape in a self-consistent way, but they still need a model for the propagation of the flame in the scales unresolved by the code. Furthermore, in three dimensions the number of degrees of freedom of the initial configuration of the white dwarf at runaway is much larger than in one dimension. Recent simulations have shown that the sensitivity of the explosion output to the initial conditions can be extremely large. New paradigms of thermonuclear supernovae have emerged from this situation, as the Pulsating Reverse Detonation. The resolution of all these issues must rely on the predictions of observational properties of the models, and their comparison with current Type Ia supernova data, including X-ray spectra of Type Ia supernova remnants.

  4. Patterns of significant seismic quiescence in the Pacific Mexican coast

    NASA Astrophysics Data System (ADS)

    Muñoz-Diosdado, Alejandro; Rudolf-Navarro, Adolfo; Barrera-Ferrer, Amilcar; Angulo-Brown, Fernando

    2014-05-01

    Mexico is one of the countries with higher seismicity. During the 20th century, 8% of all the earthquakes in the world of magnitude greater than or equal to 7.0 have taken place in Mexico. On average, an earthquake of magnitude greater than or equal to 7.0 occurred in Mexico every two and a half years. Great earthquakes in Mexico have their epicenters in the Pacific Coast in which some seismic gaps have been identified; for example, there is a mature gap in the Guerrero State Coast, which potentially can produce an earthquake of magnitude 8.2. With the purpose of making some prognosis, some researchers study the statistical behavior of certain physical parameters that could be related with the process of accumulation of stress in the Earth crust. Other researchers study seismic catalogs trying to find seismicity patterns that are manifested before the occurrence of great earthquakes. Many authors have proposed that the study of seismicity rates is an appropriate technique for evaluating how close a seismic gap may be to rupture. We designed an algorithm for identification of patterns of significant seismic quiescence by using the definition of seismic quiescence proposed by Schreider (1990). This algorithm shows the area of quiescence where an earthquake of great magnitude will probably occur. We apply our algorithm to the earthquake catalogue of the Mexican Pacific coast located between 14 and 21 degrees of North latitude and 94 and 106 degrees West longitude; with depths less or equal to 60 km and magnitude greater or equal to 4.2, which occurred from September, 1965 until December, 2014. We have found significant patterns of seismic quietude before the earthquakes of Oaxaca (November 1978, Mw = 7.8), Petatlán (March 1979, Mw = 7.6), Michoacán (September 1985, Mw = 8.0, and Mw = 7.6) and Colima (October 1995, Mw = 8.0). Fortunately, in this century have not occurred earthquakes of great magnitude in Mexico, however, we have identified well-defined seismic

  5. INSTRUMENTS AND METHODS OF INVESTIGATION Nanostructures in controlled thermonuclear fusion devices

    NASA Astrophysics Data System (ADS)

    Krauz, V. I.; Martynenko, Yurii V.; Svechnikov, N. Yu; Smirnov, Valentin P.; Stankevich, V. G.; Khimchenko, L. N.

    2011-01-01

    It is shown that the presence of nano-sized and nano-structured erosion products not only affects the operation of thermonuclear devices but also, to a large extent, determines the safety and economy of future thermonuclear reactors. The formation mechanisms and the characteristics and properties of deposited films and nano-sized dust that form in tokamaks are reviewed.

  6. Impact of Restless Legs Syndrome on Cardiovascular Autonomic Control

    PubMed Central

    Bertisch, Suzanne M.; Muresan, Cristen; Schoerning, Laura; Winkelman, John W.; Taylor, J. Andrew

    2016-01-01

    Study Objectives: To examine whether patients with restless legs syndrome demonstrate specific alterations in cardiovascular autonomic control. Methods: Patients with moderate-severe restless legs syndrome (n = 20, 80% female) and controls (n = 20) matched for age, sex, body mass index, and free of hypertension and cardiovascular disease were enrolled. We assessed cardiovagal baroreflex gain via the modified Oxford technique, sympathetically mediated vascular responses to isometric exercise to fatigue, bradycardiac response to Valsalva maneuver, and respiratory sinus arrhythmia during paced breathing. Standard electrocardiography, beat-by-beat arterial pressure, respiration, and popliteal blood flow velocity were recorded continuously. Results: Resting blood pressure and heart rate were similar between groups. However, baroreflex gain averaged 14.3 ± 1.4 msec/mm Hg in restless legs syndrome and was lower than in controls (22.6 ± 3.5 msec/mm Hg, P = 0.04). Hemodynamic responses to isometric exercise were similar between groups, though participants with restless legs syndrome had lower leg blood flow (P < 0.001), with greater leg vascular resistance (P < 0.0001), before and during isometric exercise. Respiratory sinus arrhythmia and Valsalva ratios were similar between groups. Neither baroreflex gain nor vascular resistance was correlated with sleep duration, sleep quality, or symptom duration. Conclusion: Patients with restless legs syndrome demonstrate compromised cardiovagal control, specific to the arterial baroreflex, with greater peripheral vascular resistance, potentially due to heightened sympathetic outflow. These autonomic alterations may directly relate to the higher prevalence of cardiovascular disease in restless legs syndrome. Citation: Bertisch SM, Muresan C, Schoerning L, Winkelman JW, Taylor JA. Impact of restless legs syndrome on cardiovascular autonomic control. SLEEP 2016;39(3):565–571. PMID:26564128

  7. Sleep apnea in patients reporting insomnia or restless legs symptoms.

    PubMed

    Bianchi, M T; Goparaju, B; Moro, M

    2016-01-01

    Insomnia and restless legs syndrome (RLS) are defined by self-reported symptoms, and polysomnography (PSG) is not routinely indicated. Occult obstructive sleep apnea (OSA), common even in asymptomatic adults, may complicate management of patients presenting with insomnia or restless legs. To this end, we investigated objective sleep apnea metrics in a large retrospective cohort according to self-reported symptom profiles. We compared sleep apnea findings in patients referred to our center according to self-reported symptoms associated with insomnia, sleep apnea, and restless legs. The cohort included over 1900 adults who underwent diagnostic (n = 1418) or split-night (n = 504) PSGs and completed a symptom and medical history questionnaire. More than 30% of patients who did not endorse any OSA symptoms, but did endorse insomnia or restless legs symptoms, were found to have OSA based on apnea-hypopnea index (AHI) >5 during overnight laboratory testing. Regression models of the full cohort showed that the risk of OSA was related, as expected, to older age, male sex, elevated body mass index, and presence of OSA symptoms. The presence of insomnia symptoms did not alter the risk of OSA. The presence of restless legs symptoms showed a small odds ratio for lowered OSA risk. Objective evidence of OSA occurs similarly in those with insomnia or restless legs symptoms, even among those without self-reported OSA symptoms. Providers should be aware of the potential for occult OSA in populations with insomnia and restless legs, which may complicate their management in addition to presenting an independent medical risk itself. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Restless legs syndrome in patients on dialysis.

    PubMed

    Al-Jahdali, Hamdan H; Al-Qadhi, Waleed A; Khogeer, Haithm A; Al-Hejaili, Fayez F; Al-Ghamdi, Saeed M; Al Sayyari, Abdullah A

    2009-05-01

    Restless legs syndrome (RLS) is an extremely distressing problem experienced by patients on dialysis; the prevalence appears to be greater than in the general population, with a wide variation from 6.6% to 80%. The diagnosis of RLS is a clinical one, and its definition has been clarified and standardized by internationally recognized diagnostic criteria, published in 1995 by the International Restless Legs Syndrome Study Group (IRLSSG). This study was designed to find out the prevalence of RLS in Saudi patients with end-stage renal disease (ESRD) on maintenance dialysis. This is a cross sectional study carried out between May and Sept 2007 at two centers, King Abdulaziz Medical City-King Fahad National Guard Hospital (KAMC-KFNGH), Riyadh and King Faisal Specialist Hospital and Research Centre (KFHRC), Jeddah, Saudi Arabia. Data were gathered on 227 Saudi patients on chronic maintenance hemodialysis or chronic peritoneal dialysis. The prevalence of RLS was measured using IRLSSG's RLS Questionnaire (RLSQ). Potential risk factors for RLS including other sleep disorders, underlying cause of chronic renal failure, duration on dialysis, dialysis shift, biochemical tests and demographic data were also evaluated. The overall prevalence of RLS was 50.22% including 53.7% males and 46.3% females. Their mean age was 55.7 +/- 17.2 years and mean duration on dialysis 40.4 +/- 37.8 months. Significant predictors of RLS were history of diabetes mellitus (DM), coffee intake, afternoon dialysis, gender and type of dialysis (P= 0.03, 0.01, < 0.001, 0.05 and 0.009 respectively). Patients with RLS were found to be at increased risk of having insomnia and excessive daytime sleepiness (EDS) (P= < 0.001 and 0.001, respectively). Our study suggests that RLS is a very common problem in dialysis population and was significantly associated with other sleep disorders, particularly insomnia, and EDS. Optimal care of dialysis patient should include particular attention to the diagnosis and

  9. Dormancy and quiescence of skeletal muscle stem cells.

    PubMed

    Rocheteau, Pierre; Vinet, Mathilde; Chretien, Fabrice

    2015-01-01

    The skeletal muscle of vertebrates has a huge regenerative capacity. When destroyed after different types of injury, this organ can regenerate very quickly (less than 20 days following myotoxin injection in the mouse) ad integrum and repeatedly. The cell responsible for this regeneration is the so-called satellite cell, the muscle stem cell that lies on top of the muscle fibre, a giant, multinucleated cell that contains the contractile material. When injected in the muscle, satellite cells can efficiently differentiate into contractile muscle fibres. The satellite cell shows great therapeutic potential; and its regenerative capacity has triggered particular interest in the field of muscular degeneration. In this review we will focus on one particular property of the satellite cell: its quiescence and dormancy. Indeed adult satellite cells are quiescent; they lie between the basal lamina and the basement membrane of the muscle fibre, ready to proliferate, and fuse in order to regenerate myofibers upon injury. It has recently been shown that a subpopulation of satellite cells is able to enter dormancy in human and mice cadavers. Dormancy is defined by a low metabolic state, low mobility, and a long lag before division when plated in vitro, compared to quiescent cells. This definition is also based on current knowledge about long-term hematopoietic stem cells, a subpopulation of stem cells that are described as dormant based on the same criteria (rare division and low metabolism when compared to progeny which are dividing more often). In the first part of this review, we will provide a description of satellite cells which addresses their quiescent state. We will then focus on the uneven distribution of satellite cells in the muscle and describe evidence that suggests that their dormancy differs from one muscle to the next and that one should be cautious when making generalisations regarding this cellular state. In a second part, we will discuss the transition between

  10. Cellular quiescence in mammary stem cells and breast tumor stem cells: got testable hypotheses?

    PubMed

    Harmes, David C; DiRenzo, James

    2009-03-01

    Cellular quiescence is a state of reversible cell cycle arrest and has more recently been shown to be a blockade to differentiation and to correlate with resistance to cancer chemotherapeutics and other xenobiotics; features that are common to adult stem cells and possibly tumor stem cells. The biphasic kinetics of mammary regeneration, coupled to its cyclic endocrine control suggest that mammary stem cells most likely divide during a narrow window of the regenerative cycle and return to a state of quiescence. This would enable them to retain their proliferative capacity, resist differentiation signals and preserve their prolonged life span. There is accumulating evidence that mammary stem cells and other adult stem cells utilize quiescence for this purpose, however the degree to which tumor stem cells do so is largely unknown. The retained proliferative capacity of mammary stem cells likely enables them to accumulate and harbor mutations that lead to breast cancer initiation. However it is currently unclear if these causative lesions lead to defective or deranged quiescence in mammary stem cells. Evidence of such effects could potentially lead to the development of diagnostic systems that monitor mammary stem cell quiescence or activation. Such systems may be useful for the evaluation of patients who are at significant risk of breast cancer. Additionally quiescence has been postulated to contribute to therapeutic resistance and tumor recurrence. This review aims to evaluate what is known about the mechanisms governing cellular quiescence and the role of tumor stem cell quiescence in breast cancer recurrence.

  11. The Internal Restlessness Scale: Performance of College Students with and without ADHD.

    ERIC Educational Resources Information Center

    Weyandt, Lisa L.; Iwaszuk, Wendy; Fulton, Katie; Ollerton, Micha; Beatty, Noelle; Fouts, Hillary; Schepman, Stephen; Greenlaw, Corey

    2003-01-01

    A study explored the construct of mental restlessness in 20 college students with and without attention deficit hyperactivity disorder (ADHD) using the Internal Restlessness Scale (IRS). Students with ADHD reported significantly higher ratings of internal restlessness. The IRS appears to have adequate test-retest reliability and a four-factor…

  12. Relativistic outflow from two thermonuclear shell flashes on neutron stars

    NASA Astrophysics Data System (ADS)

    in't Zand, J. J. M.; Keek, L.; Cavecchi, Y.

    2014-08-01

    We study the exceptionally short (32-43 ms) precursors of two intermediate-duration thermonuclear X-ray bursts observed with the Rossi X-ray Timing Explorer from the neutron stars in 4U 0614+09 and 2S 0918-549. They exhibit photon fluxes that surpass those at the Eddington limit later in the burst by factors of 2.6 to 3.1. We are able to explain both the short duration and the super-Eddington flux by mildly relativistic outflow velocities of 0.1c to 0.3c subsequent to the thermonuclear shell flashes on the neutron stars. These are the highest velocities ever measured from any thermonuclear flash. The precursor rise times are also exceptionally short: about 1 ms. This is inconsistent with predictions for nuclear flames spreading laterally as deflagrations and suggests detonations instead. This is the first time that a detonation is suggested for such a shallow ignition column depth (yign ≈ 1010 g cm-2). The detonation would possibly require a faster nuclear reaction chain, such as bypassing the α-capture on 12C with the much faster 12C(p,γ)13N(α,p)16O process previously proposed. We confirm the possibility of a detonation, albeit only in the radial direction, through the simulation of the nuclear burning with a large nuclear network and at the appropriate ignition depth, although it remains to be seen whether the Zel'dovich criterion is met. A detonation would also provide the fast flame spreading over the surface of the neutron star to allow for the short rise times. This needs to be supported by future two-dimensional calculations of flame spreading at the relevant column depth. As an alternative to the detonation scenario, we speculate on the possibility that the whole neutron star surface burns almost instantly in the auto-ignition regime. This is motivated by the presence of 150 ms precursors with 30 ms rise times in some superexpansion bursts from 4U 1820-30 at low ignition column depths of ~108 g cm-2.

  13. Corticosterone predicts nocturnal restlessness in a long-distance migrant.

    PubMed

    Eikenaar, Cas; Klinner, Thomas; Stöwe, Mareike

    2014-07-01

    The decision made by migrating birds to stop refueling and to depart from stopover depends on cues from innate rhythms, intrinsic factors such as fuel reserves, and extrinsic factors such as weather conditions. The physiological mechanism behind this decision, however, is largely unexplored. The transition from refueling to flight involves an increase in both locomotion and energetic demands. Because, at baseline levels, corticosterone stimulates locomotion and is involved in the mobilization of energy, this hormone could encourage departure of migrants. We collected field data on baseline corticosterone, migratory restlessness, and actual departure in northern wheatears at stopover. Additionally, in refueling long-term captive conspecifics, we measured migratory restlessness while simultaneously collecting droppings to determine glucocorticoid metabolite (GCM) levels. We found that migratory restlessness at stopover was positively correlated with corticosterone level. Similarly, in refueling long-term captive birds, migratory restlessness was positively correlated with concurrently measured GCM levels in droppings. To our best knowledge, our study is the first to simultaneously measure a hormonal signal and migratory restlessness. In conclusion, our results are consistent with the hypothesis that, by increasing locomotor activity, baseline corticosterone is involved in the regulation of departure of migrants at stopover. Future studies could reveal how corticosterone is up-regulated in migrants that are ready to depart.

  14. Restless legs syndrome and pregnancy: a review.

    PubMed

    Srivanitchapoom, Prachaya; Pandey, Sanjay; Hallett, Mark

    2014-07-01

    Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery.

  15. Pramipexole alters thermoregulation in restless legs syndrome.

    PubMed

    Salminen, Aaro V; Rimpilä, Ville; Polo, Olli

    2014-12-15

    Previous studies have associated restless legs syndrome (RLS) with peripheral hypoxia and impaired thermoregulation in the lower extremities. We performed long-term monitoring of skin temperatures in order to investigate whether these findings could be explained by reduced blood flow to the peripheral tissues. 96-hour continuous measurements of skin temperature were performed both in the distal and proximal parts of the body of 15 patients with RLS and 14 healthy controls. During the recording, the patients participated in suggested immobilization tests both with and without pramipexole medication. We found no baseline differences in distal or proximal skin temperature between patients and controls in daytime or during immobilization. However, pramipexole significantly increased distal skin temperature in the patient group during immobilization (31.1°C vs. 32.9°C, p < 0.05). Daytime temperatures were not affected by therapy or disease status. The data suggest that patients with RLS and healthy controls have similar blood flow to the peripheral skin tissue. Pramipexole, however, alters thermoregulation and the previous studies might have been biased by medication. Dopaminergic medication is a major confounding factor when assessing peripheral phenomena in RLS and should be controlled for in the future studies. © 2014 American Academy of Sleep Medicine.

  16. [RESTLESS LEGS SYNDROME--WILLIS-EKBOM DISEASE].

    PubMed

    Ruppert, Élisabeth; Bataillard, Marc; Bourgin, Patrice

    2015-09-01

    Restless legs syndrome (RLS) is a sensorimotor disorder with a high prevalence (10% in Caucasian populations). It is a purely clinical diagnosis characterized by an urge to move the lower limbs usually accompanied or caused by unpleasant sensations in the legs with an improvement in symptoms with movement. These sensations occur during inactivity or at rest and worsen in the evening or at night. RLS may not only impact the quality of life for an individual, but may also increase mortality. Disease markers such as genetic predispositions have been identified, as well as reduced iron stores with altered intracerebral iron homeostasis and dopaminergic dysfunction. Medication is often necessary in severe forms, with low doses of dopaminergic agonists being the first-line of treatment. The use of α2δ ligands is an alternative. Finally benzodiazepines and opioid medications can be effective in refractory cases. In less severe forms of RLS, a non-pharmacological approach is usually sufficient with avoidance of stimulants and correction of contributing factors.

  17. Restless legs syndrome in hemodialysis patients.

    PubMed

    Rafie, Shahram; Jafari, Majid; Azizi, Mostafa; Bahadoram, Mohammad; Jafari, Shima

    2016-03-01

    Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable sensation of paresthesia in legs that subsequently causes involuntary and continuous movement of the lower limbs, especially at rest. Its prevalence in hemodialysis is more than that in the general population. Different risk factors have been suggested for RLS. We studied the prevalence and risk factors of RLS in 137 hemodialysis patients followed up at our center. The patients completed at least three months on dialysis and fulfilled four criteria for the diagnosis of RLS. We compared the patients with and without RLS, and the odds ratios (ORs) were estimated by the logistic regression models. The prevalence of RLS was 36.5% in the study patients. Among the variables, diabetes was the only predicting factor for the development of RLS. The diabetic patients may be afflicted with RLS 2.25 times more than the non-diabetics. Women developed severe RLS 5.23 times more than men. Neurodegeneration, decrease in dopamine level, higher total oxidant status, and neuropathy in diabetic patients may explain the RLS symptoms.

  18. Restless legs syndrome and pregnancy: A review

    PubMed Central

    Srivanitchapoom, Prachaya; Pandey, Sanjay; Hallett, Mark

    2014-01-01

    Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery. PMID:24768121

  19. Restless legs syndrome associated with major diseases

    PubMed Central

    Allen, Richard; Högl, Birgit; Paulus, Walter

    2016-01-01

    Recent publications on both the genetics and environmental factors of restless legs syndrome (RLS) defined as a clinical disorder suggest that overlapping genetic risk factors may play a role in primary (idiopathic) and secondary (symptomatic) RLS. Following a systematic literature search of RLS associated with comorbidities, we identified an increased prevalence of RLS only in iron deficiency and kidney disease. In cardiovascular disease, arterial hypertension, diabetes, migraine, and Parkinson disease, the methodology of studies was poor, but an association might be possible. There is insufficient evidence for conditions such as anemia (without iron deficiency), chronic obstructive pulmonary disease, multiple sclerosis, headache, stroke, narcolepsy, and ataxias. Based on possible gene–microenvironmental interaction, the classifications primary and secondary RLS may suggest an inappropriate causal relation. We recognize that in some conditions, treatment of the underlying disease should be achieved as far as possible to reduce or eliminate RLS symptoms. RLS might be seen as a continuous spectrum with a major genetic contribution at one end and a major environmental or comorbid disease contribution at the other. PMID:26944272

  20. Pediatric restless legs syndrome diagnostic criteria: an update by the International Restless Legs Syndrome Study Group.

    PubMed

    Picchietti, Daniel L; Bruni, Oliviero; de Weerd, Al; Durmer, Jeffrey S; Kotagal, Suresh; Owens, Judith A; Simakajornboon, Narong

    2013-12-01

    Specific diagnostic criteria for pediatric restless legs syndrome (RLS) were published in 2003 following a workshop at the National Institutes of Health. Due to substantial new research and revision of the adult RLS diagnostic criteria, a task force was chosen by the International Restless Legs Syndrome Study Group (IRLSSG) to consider updates to the pediatric diagnostic criteria. A committee of seven pediatric RLS experts developed a set of 15 consensus questions to review, conducted a comprehensive literature search, and extensively discussed potential revisions. The committee recommendations were approved by the IRLSSG executive committee and reviewed by the IRLSSG membership. The pediatric RLS diagnostic criteria were simplified and integrated with the newly revised adult RLS criteria. Specific recommendations were developed for pediatric application of the criteria, including consideration of typical words used by children to describe their symptoms. Pediatric aspects of differential diagnosis, comorbidity, and clinical significance were then defined. In addition, the research criteria for probable and possible pediatric RLS were updated and criteria for a related condition, periodic limb movement disorder (PLMD), were clarified. Revised diagnostic criteria for pediatric RLS have been developed, which are intended to improve clinical practice and promote further research. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  1. ITER (International Thermonuclear Experimental Reactor) reactor building design study

    SciTech Connect

    Thomson, S.L.; Blevins, J.D.; Delisle, M.W.; Canadian Fusion Fuels Technology Project, Mississauga, ON )

    1989-01-01

    The International Thermonuclear Experimental Reactor (ITER) is at the midpoint of a two-year conceptual design. The ITER reactor building is a reinforced concrete structure that houses the tokamak and associated equipment and systems and forms a barrier between the tokamak and the external environment. It provides radiation shielding and controls the release of radioactive materials to the environment during both routine operations and accidents. The building protects the tokamak from external events, such as earthquakes or aircraft strikes. The reactor building requirements have been developed from the component designs and the preliminary safety analysis. The equipment requirements, tritium confinement, and biological shielding have been studied. The building design in progress requires continuous iteraction with the component and system designs and with the safety analysis. 8 figs.

  2. Multiplexing thermography for International Thermonuclear Experimental Reactor divertor targets

    SciTech Connect

    Itami, K.; Sugie, T.; Vayakis, G.; Walker, C.

    2004-10-01

    The concept of multiplexing thermography is applied to the design of the divertor thermography system for International Thermonuclear Experimental Reactor (ITER). The combination of the front mirror with multiellipticity and a Czerney-Turner spectrometer with a 0.2 mm pitched multichannel detector enables a spatial resolution of 3 mm and a time resolution of 20 {mu}s above a target temperature of 300 deg. C to be achieved. This should be sufficient to measure ELM heat fluxes to the targets in ITER. To satisfy the measurement requirement, it is very important to keep an accurate alignment around the optical axis against movement of the vessel during the plasma discharges. Several key engineering problems, such as the survivability of components against mirror coating by redeposited divertor material, remain to be solved. Potential solutions have been identified.

  3. Joining of carbon-carbon composites for thermonuclear fusion applications

    SciTech Connect

    Salvo, M.; Lemoine, P.; Ferraris, M.; Montorsi, M.; Merola, M.

    1997-01-01

    Carbon-fiber-reinforced carbon (CfC) composites have been joined by using different joining agents: metals (silicon, aluminum, and titanium), an intermetallic compound (magnesium silicide, Mg{sub 2}Si), and glasses (borosilicates and zinc borates). These joining agents have been chosen by considering their possible use in a thermonuclear fusion reactor, as suggested by their low-activation properties, reasonably high working temperature, industrial feasibility, and potential scale-up of the joined carbon-carbon structures using pressureless-processing techniques. Each joined structure (CfC composite-joining material-CfC composite) has been first morphologically characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffractometry. Then, single-lap shear tests have been performed on the most-promising joined structures, i.e., silicon- and aluminum-joined CfC-composite samples, which have shown an average shear strength of 22 and 10 MPa, respectively.

  4. Laser induced sonofusion: A new road toward thermonuclear reactions

    NASA Astrophysics Data System (ADS)

    Sadighi-Bonabi, Rasoul; Gheshlaghi, Maryam

    2016-03-01

    The Possibility of the laser assisted sonofusion is studied via single bubble sonoluminescence (SBSL) in Deuterated acetone (C3D6O) using quasi-adiabatic and hydro-chemical simulations at the ambient temperatures of 0 and -28.5 °C. The interior temperature of the produced bubbles in Deuterated acetone is 1.6 × 106 K in hydro-chemical model and it is reached up to 1.9 × 106 K in the laser induced SBSL bubbles. Under these circumstances, temperature up to 107 K can be produced in the center of the bubble in which the thermonuclear D-D fusion reactions are promising under the controlled conditions.

  5. The Thermonuclear Runaway and the Classical Nova Outburst

    NASA Astrophysics Data System (ADS)

    Starrfield, S.; Iliadis, C.; Hix, W. R.

    2016-05-01

    Nova explosions occur on the white dwarf component of a cataclysmic variable binary stellar system that is accreting matter lost by its companion. When sufficient material has been accreted by the white dwarf, a thermonuclear runaway occurs and ejects material in what is observed as a classical nova explosion. We describe both the recent advances in our understanding of the progress of the outburst and outline some of the puzzles that are still outstanding. We report on the effects of improving both the nuclear reaction rate library and including a modern nuclear reaction network in our one-dimensional, fully implicit, hydrodynamic computer code. In addition, there has been progress in observational studies of supernovae Ia with implications about the progenitors, and we discuss that in this review.

  6. Thermonuclear runaways investigated using drip line beta decays

    NASA Astrophysics Data System (ADS)

    Wrede, Christopher

    2016-09-01

    In close binary star systems, mass transfer onto the surface of a white dwarf or neutron star can lead to spectacular periodic emissions including classical novae and x-ray bursts. Accurate nuclear reaction rates are needed to model energy generation and nucleosynthesis in these thermonuclear runaways enabling meaningful comparisons to observations. An experimental program has been established at the National Superconducting Cyclotron Laboratory to constrain the most influential nuclear physics uncertainties using the beta decays of nuclides adjacent to the proton drip line. In particular, the beta decays of 20Mg, 26P, and 31Cl have been used to investigate the 15O(α,γ)19Ne, 25Al(p,γ)26Si, and 30P(p,γ)31S reaction rates, respectively. These studies relate to the shapes of x-ray burst light curves, the production of the radionuclide 26Al in the Milky Way, and the identification of presolar nova grains in meteoritic material.

  7. Acoustically driven spherical implosions and the possibility of thermonuclear reactions

    NASA Astrophysics Data System (ADS)

    Gaitan, D. Felipe; Tessien, Ross

    2003-04-01

    Acoustically driven, gas-filled cavities in liquids have been known to collapse violently, generating short flashes of light of ~100-ps duration. More recently, the possibility of generating fusion reactions using acoustics (acoustic inertial confinement fusion) has been considered. Results of computer simulations using the HYADES hydrocode (Cascade Applied Sciences, Inc) plus the SESAME equations of state for free collapsing and acoustically driven cavities in molten metals will be presented as well as experimental data at high ambient pressures in different liquids. Back-of-the-envelope calculations in terms of the acoustical and thermodynamic parameters necessary to achieve thermonuclear reactions will be presented in an effort to evaluate the feasibility of acoustic ICF as an energy source.

  8. On some features of plane waves of thermonuclear burn

    NASA Astrophysics Data System (ADS)

    Khishchenko, K. V.; Charakhch'yan, A. A.

    2015-01-01

    The behavior of a slow burn wave propagating over a precompressed thermonuclear fuel heated by several shock waves generated by a laser pulse is studied. It is shown that such a burn wave can rapidly increase the fuel density ahead of the wave front and transform to a pair of detonation waves moving in the opposite directions. Hydrodynamic equations with a linear velocity profile are solved. It is found that the proton beam intensity necessary for ignition increases with the initial fuel density in accordance with the known formula generalizing results of two-dimensional simulations. A possibility of using results of one-dimensional simulations for determining the energy of ignition of a cylindrical target is discussed.

  9. Current drive at plasma densities required for thermonuclear reactors.

    PubMed

    Cesario, R; Amicucci, L; Cardinali, A; Castaldo, C; Marinucci, M; Panaccione, L; Santini, F; Tudisco, O; Apicella, M L; Calabrò, G; Cianfarani, C; Frigione, D; Galli, A; Mazzitelli, G; Mazzotta, C; Pericoli, V; Schettini, G; Tuccillo, A A

    2010-08-10

    Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.

  10. Transport simulation of ITER (International Thermonuclear Engineering Reactor) startup

    SciTech Connect

    Attenberger, S.E.; Houlberg, W.A.

    1989-01-01

    The present International Thermonuclear Engineering Reactor (ITER) reference configurations are the Technology Phase,'' in which the plasma current is maintained noninductively at a subignition density, and the Physics Phase,'' which is ignited but requires inductive maintenance of the current. The WHIST 1.5-D transport code is used to evaluate the volt-second requirements of both configurations. A slow current ramp (60-80's) is required for fixed-radius startup in ITER to avoid hollow current density profiles. To reach the operating point requires about 203 V{center dot}s for the Technology Phase (18 MA) and about 270 V{center dot}s for the Physics Phase (22 MA). The resistive losses can be reduced with expanding-radius startup. 5 refs., 4 figs.

  11. Multidimensional Simulations of Thermonuclear Supernovae from the First Stars

    NASA Astrophysics Data System (ADS)

    Chen, K. J.; Heger, A.; Almgren, A.

    2012-07-01

    Theoretical models suggest that the first stars in the universe could have been very massive, with typical masses ≥ 100 M⊙ . Many of them might have died as energetic thermonuclear explosions known as pair-instability supernovae (PSNe). We present multidimensional numerical simulations of PSNe with the new radiation-hydrodynamics code CASTRO. Our models capture all explosive burning and follow the explosion until the shock breaks out from the stellar surface. We find that fluid instabilities driven by oxygen and helium burning arise at the upper and lower boundaries of the oxygen shell ˜ 20 - 100 sec after the explosion begins. Later, when the shock reaches the hydrogen envelope a strong reverse shock forms that rapidly develops additional Rayleigh-Taylor instabilities. In red supergiant progenitors, the amplitudes of these instabilities are sufficient to mix the supernova's ejecta and alter its observational signature. Our results provide useful predictions for the detection of PSNe by forthcoming telescopes.

  12. Laser induced sonofusion: A new road toward thermonuclear reactions

    SciTech Connect

    Sadighi-Bonabi, Rasoul; Gheshlaghi, Maryam

    2016-03-15

    The Possibility of the laser assisted sonofusion is studied via single bubble sonoluminescence (SBSL) in Deuterated acetone (C{sub 3}D{sub 6}O) using quasi-adiabatic and hydro-chemical simulations at the ambient temperatures of 0 and −28.5 °C. The interior temperature of the produced bubbles in Deuterated acetone is 1.6 × 10{sup 6} K in hydro-chemical model and it is reached up to 1.9 × 10{sup 6} K in the laser induced SBSL bubbles. Under these circumstances, temperature up to 10{sup 7} K can be produced in the center of the bubble in which the thermonuclear D-D fusion reactions are promising under the controlled conditions.

  13. Influence of thermonuclear effects on the collapse of supermassive stars

    NASA Astrophysics Data System (ADS)

    Montero, Pedro J.; Janka, H.-T.; Müller, E.; Müller, B.

    2011-09-01

    We present results of general relativistic simulations of collapsing supermassive stars using the two-dimensional general relativistic numerical code Nada, which solves the Einstein equations written in the BSSN formalism and the general relativistic hydrodynamic equations with high resolution shock capturing schemes. These numerical simulations use a tabulated equation of state which includes effects of radiation and gas pressure, and those associated with the electron-positron pairs. We also take into account the effect of thermonuclear energy released by hydrogen and helium burning. We find that objects with mass ≈ 5 × 105M and initial metallicity greater than ZCNO ≈ 0.004 do explode if non-rotating, while the threshold metallicity for an explosion is reduced to ZCNO ≈ 0.002 for objects uniformly rotating.

  14. Close Binary Progenitors and Ejected Companions of Thermonuclear Supernovae

    NASA Astrophysics Data System (ADS)

    Geier, S.; Kupfer, T.; Heber, U.; Nemeth, P.; Ziegerer, E.; Irrgang, A.; Schindewolf, M.; Marsh, T. R.; Gänsicke, B. T.; Barlow, B. N.; Bloemen, S.

    2017-03-01

    Hot subdwarf stars (sdO/Bs) are evolved core helium-burning stars with very thin hydrogen envelopes, which can be formed by common envelope ejection. Close sdB binaries with massive white dwarf (WD) companions are potential progenitors of thermonuclear supernovae type Ia (SN Ia). We discovered such a progenitor candidate as well as a candidate for a surviving companion star, which escapes from the Galaxy. More candidates for both types of objects have been found by cross-matching known sdB stars with proper motion and light curve catalogues. We found 72 sdO/B candidates with high Galactic restframe velocities, 12 of them might be unbound to our Galaxy. Furthermore, we discovered the second-most compact sdB+WD binary known. However, due to the low mass of the WD companion, it is unlikely to be a SN Ia progenitor.

  15. Analytical Model for the Thermonuclear Instability in IGNITOR

    NASA Astrophysics Data System (ADS)

    Cardinali, A.; Sonnino, G.; Coppi, B.

    2013-10-01

    The non-linear energy balance equation for thermal equilibrium and stability, is analytically and numerically investigated in order to study the thermonuclear instability in the IGNITOR experiment facility. The expressions for the ion and the electron thermal coefficients, introduced in the thermal energy balance equation, are obtained by solving the nonlinear transport equations relevant to several collisional transport regimes (in particular the banana regime). The differential equation for the temperature profile at equilibrium is solved and the resulting profile is compared with the results obtained by a full transport code. The growth of the perturbation in the temperature is analyzed by integrating the equation in time. A scenario is considered where IGNITOR is led to operate in a slightly sub-critical regime by adding a small fraction of 3He to the nominal 50-50 Deuterium-Tritium mixture and heating the plasma by ICRH power. Sponsored in part by the US DOE.

  16. The Dynamic Mutation Characteristics of Thermonuclear Reaction in Tokamak

    PubMed Central

    Li, Jing; Quan, Tingting; Zhang, Wei; Deng, Wei

    2014-01-01

    The stability and bifurcations of multiple limit cycles for the physical model of thermonuclear reaction in Tokamak are investigated in this paper. The one-dimensional Ginzburg-Landau type perturbed diffusion equations for the density of the plasma and the radial electric field near the plasma edge in Tokamak are established. First, the equations are transformed to the average equations with the method of multiple scales and the average equations turn to be a Z2-symmetric perturbed polynomial Hamiltonian system of degree 5. Then, with the bifurcations theory and method of detection function, the qualitative behavior of the unperturbed system and the number of the limit cycles of the perturbed system for certain groups of parameter are analyzed. At last, the stability of the limit cycles is studied and the physical meaning of Tokamak equations under these parameter groups is given. PMID:24892099

  17. The dynamic mutation characteristics of thermonuclear reaction in Tokamak.

    PubMed

    Li, Jing; Quan, Tingting; Zhang, Wei; Deng, Wei

    2014-01-01

    The stability and bifurcations of multiple limit cycles for the physical model of thermonuclear reaction in Tokamak are investigated in this paper. The one-dimensional Ginzburg-Landau type perturbed diffusion equations for the density of the plasma and the radial electric field near the plasma edge in Tokamak are established. First, the equations are transformed to the average equations with the method of multiple scales and the average equations turn to be a Z 2-symmetric perturbed polynomial Hamiltonian system of degree 5. Then, with the bifurcations theory and method of detection function, the qualitative behavior of the unperturbed system and the number of the limit cycles of the perturbed system for certain groups of parameter are analyzed. At last, the stability of the limit cycles is studied and the physical meaning of Tokamak equations under these parameter groups is given.

  18. Aedes aegypti pharate 1st instar quiescence affects larval fitness and metal tolerance.

    PubMed

    Perez, Mario H; Noriega, Fernando G

    2012-06-01

    The eggs of the mosquito Aedes aegypti possess the ability to undergo an extended quiescence hosting a fully developed 1st instar larvae within the chorion. As a result of this life history trait pharate larvae can withstand months of quiescence inside the egg where they depend on stored maternal reserves. A. aegypti mosquitoes are frequently associated with urban habitats that may contain significant metal pollution. Therefore, the duration of quiescence and extent of nutritional depletion may affect the physiology and survival of larvae that hatch in a suboptimal habitat. The aim of this study was to determine the effect of an extended quiescence on larval nutrient reserves and the subsequent effects of metal exposure on larval fitness, survival and development. We hypothesized that an extended quiescence would reduce nutritional reserves and alter the molecular response to metal exposure thereby reducing larval survival and altering larval development. As a molecular marker for metal stress responses, we evaluated transcriptional changes in the metallothionein gene (AaMtn) in response to quiescence and metal exposure. Extended 1st instar quiescence resulted in a significant decrease in lipid reserves and negatively affected larval fitness and development. AaMtn transcription and metal tolerance were compromised in first instars emerged from eggs that had undergone an extended quiescence. These findings suggest that newly emerged mosquito larvae that had survived a relatively long pharate 1st instar quiescence (as might occur during a dry season) are more vulnerable to environmental stress. Pharate 1st instar quiescence could have implications for vector control strategies. Newly emerged mosquito larvae at the end of the dry season or start of the wet season are physiologically compromised, and therefore potentially more susceptible to vector control strategies than mosquito larvae hatched subsequently throughout the wet season. Published by Elsevier Ltd.

  19. Demonstration of thermonuclear conditions in Magnetized Liner Inertial Fusion experiments

    NASA Astrophysics Data System (ADS)

    Gomez, Matthew

    2014-10-01

    The Magnetized Liner Inertial Fusion concept utilizes a magnetic field and laser heating to relax the implosion requirements to achieve inertial confinement fusion. The first experiments to test the concept were recently conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z coils. Despite the relatively slow implosion velocity (70 km/s) in these experiments, electron and ion temperatures at stagnation were approximately 3 keV, and thermonuclear DD neutron yields up to 2e12 have been produced. X-ray emission from the fuel at stagnation had a width ranging from 60-120 microns over a roughly 6 mm height and lasted approximately 2 ns. X-ray spectra from these experiments are consistent with a stagnation density of the hot fuel equal to 0.4 g/cm3 . In these experiments 1-5e10 secondary DT neutrons were produced. Given that the areal density of the plasma was approximately 2 mg/cm2, this indicates the stagnation plasma was significantly magnetized. This is consistent with the anisotropy observed in the DT neutron time of flight spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and DD yields greater than 1e10. An additional control experiment where the fuel contained a sufficient dopant fraction to radiate away the laser energy deposited in the fuel also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  20. The Internal Structure and Propagation of Magnetohydrodynamical Thermonuclear Flames

    NASA Astrophysics Data System (ADS)

    Remming, Ian S.; Khokhlov, Alexei M.

    2016-11-01

    We present general equations for non-ideal, reactive flow magnetohydrodynamics (RFMHD) in the form best suited for describing thermonuclear combustion in high-density degenerate matter of SNe Ia. The relative importance of various non-ideal effects is analyzed as a function of characteristic spatial and temporal scales of the problem. From the general RFMHD equations, we derive the one-dimensional ordinary differential equations describing the steady-state propagation of a planar thermonuclear flame front in a magnetic field. The physics of the flame is first studied qualitatively using a simple case of one-step Arrhenius kinetics, a perfect gas equation of state (EOS), and constant thermal conductivity coefficients. After that, the equations are solved, the internal flame front structure is calculated, and the flame velocity, S l , and flame thickness, δ l , are found for carbon-oxygen degenerate material of supernovae using a realistic EOS, transport properties, and detailed nuclear kinetics. The magnetic field changes the flame behavior significantly, both qualitatively and quantitatively, as compared to the non-magnetic case of classical combustion. (1) The magnetic field influences the evolutionarity of a flame front and makes it impossible for a flame to propagate steadily in a wide range of magnetic field strengths and orientations relative to the front. (2) When the flame moves steadily, it can propagate in several distinct modes, the most important being the slow C S and super-Alfvénic C sup modes. (3) The speed of the flame can be diminished or enhanced by up to several factors relative to the non-magnetic laminar flame speed.

  1. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    DOE PAGES

    Gomez, Matthew R.; Slutz, Stephen A.; Sefkow, Adam B.; ...

    2015-04-29

    In this study, the magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as highmore » as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm3. In these experiments, up to 5 ×1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.« less

  2. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experimentsa)

    NASA Astrophysics Data System (ADS)

    Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Hahn, K. D.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Ruiz, C. L.; Sinars, D. B.; Harding, E. C.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Smith, I. C.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Harvey-Thompson, A. J.; Herrmann, M. C.; Hess, M. H.; Lamppa, D. C.; Martin, M. R.; McBride, R. D.; Peterson, K. J.; Porter, J. L.; Rochau, G. A.; Savage, M. E.; Schroen, D. G.; Stygar, W. A.; Vesey, R. A.

    2015-05-01

    The magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6-8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2-0.4 g/cm3. In these experiments, up to 5 × 1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1-2 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  3. Terminal restlessness: perspectives of an interdisciplinary palliative care team.

    PubMed

    Brajtman, Susan

    2005-04-01

    To explore an interdisciplinary team's perceptions of families' needs and experiences surrounding terminal restlessness. A qualitative exploratory design using two focus groups. Participants were members of an interdisciplinary palliative care team working in a palliative care unit in a university teaching hospital in Israel. The palliative care team confronted several challenging and stressful issues surrounding the management of terminal restlessness that influenced their treatment decisions and relationships with families. Four themes reflected the participants' perceptions and experiences: suffering, maintaining control, feelings of ambivalence and valuing communication to reduce conflict. Findings suggest the need for comprehensive treatment plans to meet the special supportive and information needs of these families, specific supportive strategies for the professional caregivers and further studies to develop ethical criteria and evidence-based guidelines for the use of sedation in the management of terminal restlessness.

  4. Not only limbs in atypical restless legs syndrome.

    PubMed

    Turrini, Alessandra; Raggi, Alberto; Calandra-Buonaura, Giovanna; Martinelli, Paolo; Ferri, Raffaele; Provini, Federica

    2017-04-04

    Restless legs syndrome (RLS) typically affects the limbs, but the involvement of other body parts has also been reported. In this essay, we critically review all literature reports of atypical RLS cases with unusual localizations. Applying the updated diagnostic criteria of the International restless legs syndrome study group (IRLSSG), which also consider symptoms localized outside of the lower limbs, a few of these atypical cases reported in the previous literature resulted in a definitive diagnosis of RLS. We also discuss the relationship between RLS and burning mouth syndrome (BMS) or restless genital syndrome (RGS). We conclude clinical sleep specialists should be aware of unusual RLS localizations because they respond to the usual treatment for RLS. All the IRLSSG diagnostic criteria should be applied in every suspected case, in order to establish a correct diagnosis of this disabling but treatable condition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Search for thermonuclear neutrons in a mega-ampere plasma focus

    NASA Astrophysics Data System (ADS)

    Klir, D.; Kubes, P.; Paduch, M.; Pisarczyk, T.; Chodukowski, T.; Scholz, M.; Kalinowska, Z.; Bienkowska, B.; Karpinski, L.; Kortanek, J.; Kravarik, J.; Rezac, K.; Ivanova-Stanik, I.; Tomaszewski, K.; Zielinska, E.

    2012-01-01

    Plasma focus experiments were carried out at a modified PF-1000 where the cathode disc was added in front of the anode. Experimental results indicated a fraction of thermonuclear neutrons on the mega-ampere current level. In order to prove the thermonuclear mechanism, the time of neutron production and the neutron energy spectrum were measured by time-of-flight (TOF) diagnostics. Neutron TOF signals showed that the neutron production was a multiphase process and more than one mechanism occurred simultaneously. The occurrence of the thermonuclear mechanism was most evident during the plasma stagnation at low deuterium pressures. At low filling pressures, the narrow width of the neutron energy spectra demonstrated an ion temperature of about 1 keV. The possibility of thermonuclear neutrons was studied also after the stagnation, during the main neutron emission. In this case, the thermonuclear mechanism could be verified by calculating the number of deuterons that participate in the fusion process. For the bulk of thermonuclear plasmas, a significant fraction of plasma should participate in fusion. Finally, the basic consideration of the thermonuclear mechanism in Z-pinches showed the reasonableness of the MagLIF concept.

  6. Impact of Restless Legs Syndrome on Cardiovascular Autonomic Control.

    PubMed

    Bertisch, Suzanne M; Muresan, Cristen; Schoerning, Laura; Winkelman, John W; Taylor, J Andrew

    2016-03-01

    To examine whether patients with restless legs syndrome demonstrate specific alterations in cardiovascular autonomic control. Patients with moderate-severe restless legs syndrome (n = 20, 80% female) and controls (n = 20) matched for age, sex, body mass index, and free of hypertension and cardiovascular disease were enrolled. We assessed cardiovagal baroreflex gain via the modified Oxford technique, sympathetically mediated vascular responses to isometric exercise to fatigue, bradycardiac response to Valsalva maneuver, and respiratory sinus arrhythmia during paced breathing. Standard electrocardiography, beat-by-beat arterial pressure, respiration, and popliteal blood flow velocity were recorded continuously. Resting blood pressure and heart rate were similar between groups. However, baroreflex gain averaged 14.3 ± 1.4 msec/mm Hg in restless legs syndrome and was lower than in controls (22.6 ± 3.5 msec/mm Hg, P = 0.04). Hemodynamic responses to isometric exercise were similar between groups, though participants with restless legs syndrome had lower leg blood flow (P < 0.001), with greater leg vascular resistance (P < 0.0001), before and during isometric exercise. Respiratory sinus arrhythmia and Valsalva ratios were similar between groups. Neither baroreflex gain nor vascular resistance was correlated with sleep duration, sleep quality, or symptom duration. Patients with restless legs syndrome demonstrate compromised cardiovagal control, specific to the arterial baroreflex, with greater peripheral vascular resistance, potentially due to heightened sympathetic outflow. These autonomic alterations may directly relate to the higher prevalence of cardiovascular disease in restless legs syndrome. © 2016 Associated Professional Sleep Societies, LLC.

  7. Willis-Ekbom Disease or Restless Legs Syndrome?

    PubMed

    Carlos, K; Prado, L B F; Carvalho, L B C; Prado, G F

    2015-09-01

    Restless Legs Syndrome (RLS) or Willis-Ekbom Disease (WED) is highly prevalent, but patients and healthcare providers alike know little about it. Furthermore, controversy persists as to the best way of diagnosing this nosological entity. To verify whether the term used to refer to this disease entity (Restless Legs Syndrome or Willis-Ekbom Disease) affects the prevalence of self-diagnosed RLS/WED in a sample of newly graduated physicians. Newly graduated physicians were asked to self-evaluate for the presence of RLS/WED. Briefly, participants were allocated randomly across two groups. One was asked to self-assess for RLS, while the other was asked to self-assess for WED. The evaluation form given to one group asked 'Do you have Restless Legs Syndrome?' whereas the form given to participants in the other group asked 'Do you have Willis-Ekbom Disease?'. Both forms also contained the four criteria for diagnosing RLS proposed by the International Restless Legs Syndrome Study Group (IRLSSG) and instructions for self-diagnosis according to these criteria. The study sample comprised 1413 newly graduated physicians. Of the 708 participants who were given the form that used the term RLS, 87 (12.28%) diagnosed themselves with the condition. Conversely, of 705 physicians given the form with the term WED, 13 (1.84%) diagnosed themselves with the condition (p <0.0001). A greater proportion of newly graduated physicians diagnosed themselves with RLS/WED when presented with the term Restless Legs Syndrome than when presented with the term Willis-Ekbom Disease. This suggests that the term Restless Legs Syndrome may not be the most appropriate term to denote this nosological entity. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Leg cramps and restless legs syndrome during pregnancy.

    PubMed

    Hensley, Jennifer G

    2009-01-01

    Sleep disturbance during pregnancy can result in excessive daytime sleepiness, diminished daytime performance, inability to concentrate, irritability, and the potential for an increased length of labor and increased risk of operative birth. Sleep disturbance may be the result of a sleep disorder, such as leg cramps, a common yet benign disorder, or restless legs syndrome, a sensorimotor disorder. Both disrupt sleep, are distressing to the pregnant woman, and mimic one another and other serious disorders. During pregnancy, up to 30% of women can be affected by leg cramps, and up to 26% can be affected by restless legs syndrome.

  9. A spectrophotometric study of IR Gem at outburst and quiescence

    NASA Technical Reports Server (NTRS)

    Feinswog, Laurie; Szkody, Paula; Garnavich, Peter

    1988-01-01

    Optical spectra with 2.5-A resolution obtained throughout the orbit of IR Gem during a five-day sequence beginning at an outburst state and ending at quiescence are compared with B magnitude and IUE spectra obtained throughout other quiescent-state orbits. No obvious second component is found in the emission lines. In contrast to previous results, little high-excitation He II 4686-A emission is noted, and no variation of the equivalent widths of the Balmer emission is found over the orbital cycle. The results suggest that large changes in the excitation level and in the modulation from a heated zone can take place during different quiescent states, possibly due to the interoutburst phase.

  10. Diapause and quiescence in Lutzomyia diabolica (Diptera:Psychodidae).

    PubMed

    Lawyer, P; Young, D

    1991-12-01

    Gravid, laboratory-reared Lutzomyia diabolica from Garner State Park, Texas, oviposited from May to December in an outdoor colony cage at Gainesville, Florida. Egg batches contained 100% fast-developing (nondiapause) eggs, a mixture of fast-developing and slow-developing (diapause) eggs, or 100% slow-developing eggs, depending on the time of year laid. The percent diapause eggs per batch increased from 0% in early October to 100% by December. These observations suggest that Lu. diabolica is a long-day species, depositing diapause eggs in response to shorter day length. Temperature may also modify the degree of diapause response by altering the calendar position of the critical day length. Termination of the winter diapause is probably temperature dependent. Quiescence was observed in 3rd and 4th stage larvae in both indoor and outdoor cultures and was usually associated with adverse conditions such as excessive moisture, extreme temperatures, or poor diet.

  11. Evaluation of a seismic quiescence pattern in southeastern sicily

    NASA Astrophysics Data System (ADS)

    Mulargia, F.; Broccio, F.; Achilli, V.; Baldi, P.

    1985-07-01

    Southeastern Sicily experienced a very peculiar seismic activity in historic times, with a long series of ruinous earthquakes. A last large event, with magnitude probably in excess of 7.5, occurred on Jan., 11, 1693, totally destroying the city of Catania and killing 60,000 people. Only a few moderate events were reported since then, and a seismic gap issue has been proposed on this basis. A close scrutiny of the available data further shows that all significant seismic activity ceased after year 1850, suggesting one of the largest quiescence patterns ever encountered. This is examined together with the complex tectonic setting of the region, characterized by a wrenching mechanism with most significant seismicity located in its northern graben structure. An attempt to ascertain the imminence and the size of a future earthquake through commonly accepted empirical relations based on size and duration of the quiescence pattern did not provide any feasible result. A precision levelling survey which we recently completed yielded a relative subsidence of ~ 3 mm/yr, consistent with an aseismic slip on the northern graben structure at a rate of ~ 15 mm/yr. Comparing these results with sedimentological and tidal data suggests that the area is undergoing an accelerated deformation process; this issue is further supported by Rikitake's ultimate strain statistics. If the imminence of a damaging ( M = 5.4) event is strongly favoured by Weibull statistics applied to the time series of occurrence of large events, the accumulated strain does not appear sufficient for a large earthquake ( M ⪸ 7.0). Within the limits of reliability of present semi-empirical approaches we conclude that the available evidence is consistent with the occurrence of a moderate-to-large ( M ≅ 6.0) event in the near future. Several questions regarding the application of simple models to real (and complex) tectonic settings remain nevertheless unanswered.

  12. Is HL Tauri and FU Orionis system in quiescence?

    NASA Technical Reports Server (NTRS)

    Lin, D. N. C.; Hayashi, M.; Bell, K. R.; Ohashi, N.

    1994-01-01

    A recent Nobeyama map of HL Tau reveals that gas is infalling in a flattened region approximately 1400 AU around the central star. The apparent motion of the gas provides the necessary condition for the formation of a Keplerian disk with a radius comparable to the size of the primordial solar nebula. The inferred mass infall rate onto the disk is approximately equal to 5 x 10(exp -6) solar mass/yr, which greatly exceeds the maximum estimate of the accretion rate onto the central star (approximately 7 x 10(exp -7) solar mass/yr). Consequently, mass must currently be accumulating in the disk. The estimated age and disk mass of HL Tau suggest that the accumulated matter has been flushed repeatedly on a timescale less than 10(exp 4) yr. Based on the similarites between their evolution patterns, we propose that HL Tau is an FU Orionis system in quiescence. In addition to HL Tau, 14 out of 86 pre-main-sequence stars in the Taurus-Auriga dark clouds have infrared luminosities much greater than their otherwise normal extinction-corrected stellar luminosities. These sources also tend to have flat spectra which may be due to the reprocessing of radiation by dusty, flattened, collapsing envelopes with infall rates a few 10(exp -6) solar mass/yr. Such rates are much larger than estimated central accretion rates for these systems, which suggests that mass must also be accumulating in these disks. If these sources are FU Orionis stars in quiescence, similar to HL Tau, their age and relative abundance imply that the FU Orionis phase occurs over a timescale of approixmately 10(exp 5) yr, and the quiescent phase between each outburst lasts approximately 10(exp 3) =10(exp 4) yr. These inferred properties are compatible with the scenario that FU Orionis outbursts are regulated by a thermal instability in the inner region of the disk.

  13. Cell-cycle quiescence maintains Caenorhabditis elegans germline stem cells independent of GLP-1/Notch

    PubMed Central

    Seidel, Hannah S; Kimble, Judith

    2015-01-01

    Many types of adult stem cells exist in a state of cell-cycle quiescence, yet it has remained unclear whether quiescence plays a role in maintaining the stem cell fate. Here we establish the adult germline of Caenorhabditis elegans as a model for facultative stem cell quiescence. We find that mitotically dividing germ cells—including germline stem cells—become quiescent in the absence of food. This quiescence is characterized by a slowing of S phase, a block to M-phase entry, and the ability to re-enter M phase rapidly in response to re-feeding. Further, we demonstrate that cell-cycle quiescence alters the genetic requirements for stem cell maintenance: The signaling pathway required for stem cell maintenance under fed conditions—GLP-1/Notch signaling—becomes dispensable under conditions of quiescence. Thus, cell-cycle quiescence can itself maintain stem cells, independent of the signaling pathway otherwise essential for such maintenance. DOI: http://dx.doi.org/10.7554/eLife.10832.001 PMID:26551561

  14. Aedes aegypti pharate 1st instar quiescence: a case for anticipatory reproductive plasticity.

    PubMed

    Perez, Mario H; Noriega, Fernando G

    2013-03-01

    Aedes aegypti mosquitoes use pharate 1st instar quiescence to cope with fluctuations in water availability hosting a fully developed 1st instar larvae within the chorion. The duration of this quiescence has been shown to affect larval fitness. This study sought to determine if an extended egg quiescence can elicit a plastic response resulting in an adult phenotype distinct from adults reared from short quiescence eggs. Our findings indicate that extended pharate 1st instar quiescence affects the performance and reproductive fitness of the adult female mosquito as well as the nutritional status of its progeny via maternal effects in an adaptive manner. This study demonstrates that phenotypic plasticity results as a consequence of the duration of pharate 1st instar quiescence and alternative phenotypes may exist for this mosquito with quiescence serving as a cue possibly signaling the environmental conditions that follow a dry period. These findings have implications for A. aegypti's success as a vector, geographic distribution, vector capacity and control.

  15. Distinct Mechanisms Underlie Quiescence during Two Caenorhabditis elegans Sleep-Like States.

    PubMed

    Trojanowski, Nicholas F; Nelson, Matthew D; Flavell, Steven W; Fang-Yen, Christopher; Raizen, David M

    2015-10-28

    Electrophysiological recordings have enabled identification of physiologically distinct yet behaviorally similar states of mammalian sleep. In contrast, sleep in nonmammals has generally been identified behaviorally and therefore regarded as a physiologically uniform state characterized by quiescence of feeding and locomotion, reduced responsiveness, and rapid reversibility. The nematode Caenorhabditis elegans displays sleep-like quiescent behavior under two conditions: developmentally timed quiescence (DTQ) occurs during larval transitions, and stress-induced quiescence (SIQ) occurs in response to exposure to cellular stressors. Behaviorally, DTQ and SIQ appear identical. Here, we use optogenetic manipulations of neuronal and muscular activity, pharmacology, and genetic perturbations to uncover circuit and molecular mechanisms of DTQ and SIQ. We find that locomotion quiescence induced by DTQ- and SIQ-associated neuropeptides occurs via their action on the nervous system, although their neuronal target(s) and/or molecular mechanisms likely differ. Feeding quiescence during DTQ results from a loss of pharyngeal muscle excitability, whereas feeding quiescence during SIQ results from a loss of excitability in the nervous system. Together these results indicate that, as in mammals, quiescence is subserved by different mechanisms during distinct sleep-like states in C. elegans.

  16. Distinct Mechanisms Underlie Quiescence during Two Caenorhabditis elegans Sleep-Like States

    PubMed Central

    Trojanowski, Nicholas F.; Nelson, Matthew D.; Flavell, Steven W.

    2015-01-01

    Electrophysiological recordings have enabled identification of physiologically distinct yet behaviorally similar states of mammalian sleep. In contrast, sleep in nonmammals has generally been identified behaviorally and therefore regarded as a physiologically uniform state characterized by quiescence of feeding and locomotion, reduced responsiveness, and rapid reversibility. The nematode Caenorhabditis elegans displays sleep-like quiescent behavior under two conditions: developmentally timed quiescence (DTQ) occurs during larval transitions, and stress-induced quiescence (SIQ) occurs in response to exposure to cellular stressors. Behaviorally, DTQ and SIQ appear identical. Here, we use optogenetic manipulations of neuronal and muscular activity, pharmacology, and genetic perturbations to uncover circuit and molecular mechanisms of DTQ and SIQ. We find that locomotion quiescence induced by DTQ- and SIQ-associated neuropeptides occurs via their action on the nervous system, although their neuronal target(s) and/or molecular mechanisms likely differ. Feeding quiescence during DTQ results from a loss of pharyngeal muscle excitability, whereas feeding quiescence during SIQ results from a loss of excitability in the nervous system. Together these results indicate that, as in mammals, quiescence is subserved by different mechanisms during distinct sleep-like states in C. elegans. SIGNIFICANCE STATEMENT Sleep behavior is characterized by cessation of feeding and locomotion, reduced responsiveness, and rapid reversibility. In mammals and birds, there are sleep states that have fundamentally different electrophysiology despite outwardly similar behavior. However, it is not clear whether behavioral sleep is a uniform state in animals in which electrophysiology is not readily possible. The nematode Caenorhabditis elegans displays sleep-like behavior under two conditions: during development and after exposure to environmental stressors. Here, we show that feeding and locomotion

  17. Restless Leg Syndrome Across the Globe: Epidemiology of the Restless Legs Syndrome/Willis-Ekbom Disease.

    PubMed

    Koo, Brian B

    2015-09-01

    There are more than 50 epidemiologic studies measuring the prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) across 5 of the 6 inhabited continents (not Australia), most conducted in North America and Europe. Sufficient studies have been conducted in Asia, North America, and Europe to make inferences on RLS/WED prevalence by region. RLS/WED prevalence is thought to be highest in North America and Europe and lower in Asia. These differences across regions may be explained by cultural, environmental, and genetic factors. Future investigation is needed to determine to what extent these factors affect expression of RLS/WED according to world region. Published by Elsevier Inc.

  18. Cryogenic thermonuclear fuel implosions on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Glenzer, S. H.; Callahan, D. A.; MacKinnon, A. J.; Kline, J. L.; Grim, G.; Alger, E. T.; Berger, R. L.; Bernstein, L. A.; Betti, R.; Bleuel, D. L.; Boehly, T. R.; Bradley, D. K.; Burkhart, S. C.; Burr, R.; Caggiano, J. A.; Castro, C.; Casey, D. T.; Choate, C.; Clark, D. S.; Celliers, P.; Cerjan, C. J.; Collins, G. W.; Dewald, E. L.; DiNicola, P.; DiNicola, J. M.; Divol, L.; Dixit, S.; Döppner, T.; Dylla-Spears, R.; Dzenitis, E.; Eckart, M.; Erbert, G.; Farley, D.; Fair, J.; Fittinghoff, D.; Frank, M.; Frenje, L. J. A.; Friedrich, S.; Casey, D. T.; Gatu Johnson, M.; Gibson, C.; Giraldez, E.; Glebov, V.; Glenn, S.; Guler, N.; Haan, S. W.; Haid, B. J.; Hammel, B. A.; Hamza, A. V.; Haynam, C. A.; Heestand, G. M.; Hermann, M.; Hermann, H. W.; Hicks, D. G.; Hinkel, D. E.; Holder, J. P.; Holunda, D. M.; Horner, J. B.; Hsing, W. W.; Huang, H.; Izumi, N.; Jackson, M.; Jones, O. S.; Kalantar, D. H.; Kauffman, R.; Kilkenny, J. D.; Kirkwood, R. K.; Klingmann, J.; Kohut, T.; Knauer, J. P.; Koch, J. A.; Kozioziemki, B.; Kyrala, G. A.; Kritcher, A. L.; Kroll, J.; La Fortune, K.; Lagin, L.; Landen, O. L.; Larson, D. W.; LaTray, D.; Leeper, R. J.; Le Pape, S.; Lindl, J. D.; Lowe-Webb, R.; Ma, T.; McNaney, J.; MacPhee, A. G.; Malsbury, T. N.; Mapoles, E.; Marshall, C. D.; Meezan, N. B.; Merrill, F.; Michel, P.; Moody, J. D.; Moore, A. S.; Moran, M.; Moreno, K. A.; Munro, D. H.; Nathan, B. R.; Nikroo, A.; Olson, R. E.; Orth, C. D.; Pak, A. E.; Patel, P. K.; Parham, T.; Petrasso, R.; Ralph, J. E.; Rinderknecht, H.; Regan, S. P.; Robey, H. F.; Ross, J. S.; Rosen, M. D.; Sacks, R.; Salmonson, J. D.; Saunders, R.; Sater, J.; Sangster, C.; Schneider, M. B.; Séguin, F. H.; Shaw, M. J.; Spears, B. K.; Springer, P. T.; Stoeffl, W.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Town, R. P. J.; Walters, C.; Weaver, S.; Weber, S. V.; Wegner, P. J.; Whitman, P. K.; Widmann, K.; Widmayer, C. C.; Wilde, C. H.; Wilson, D. C.; Van Wonterghem, B.; MacGowan, B. J.; Atherton, L. J.; Edwards, M. J.; Moses, E. I.

    2012-05-01

    The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These experiments use 0.17 mg of fuel with the potential for ignition and significant fusion yield conditions. The thermonuclear fuel has been fielded as a cryogenic layer on the inside of a spherical plastic capsule that is mounted in the center of a cylindrical gold hohlraum. Heating the hohlraum with 192 laser beams for a total laser energy of 1.6 MJ produces a soft x-ray field with 300 eV temperature. The ablation pressure produced by the radiation field compresses the initially 2.2-mm diameter capsule by a factor of 30 to a spherical dense fuel shell that surrounds a central hot-spot plasma of 50 μm diameter. While an extensive set of x-ray and neutron diagnostics has been applied to characterize hot spot formation from the x-ray emission and 14.1 MeV deuterium-tritium primary fusion neutrons, thermonuclear fuel assembly is studied by measuring the down-scattered neutrons with energies in the range of 10 to 12 MeV. X-ray and neutron imaging of the compressed core and fuel indicate a fuel thickness of (14 ± 3) μm, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 ± 0.09) g cm-2 result in fuel densities approaching 600 g cm-3. The fuel surrounds a hot-spot plasma with average ion temperatures of (3.5 ± 0.1) keV that is measured with neutron time of flight spectra. The hot-spot plasma produces a total fusion neutron yield of 1015 that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5±0.1)×1014 which is 70% to 75% of the total fusion yield due to the high areal density. Gamma ray measurements provide the duration of nuclear activity of (170 ± 30) ps. These indirect-drive implosions result in the highest areal densities and neutron yields achieved on laser facilities to date

  19. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    SciTech Connect

    Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Hahn, K. D.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Ruiz, C. L.; Sinars, D. B.; Harding, E. C.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Smith, I. C.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Harvey-Thompson, A. J.; Hess, M. H.; and others

    2015-05-15

    The magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 10{sup 12} have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm{sup 3}. In these experiments, up to 5 × 10{sup 10} secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm{sup 2}, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 10{sup 10}. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  20. Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

    SciTech Connect

    Gomez, Matthew R.; Slutz, Stephen A.; Sefkow, Adam B.; Hahn, Kelly D.; Hansen, Stephanie B.; Knapp, Patrick F.; Schmit, Paul F.; Ruiz, Carlos L.; Sinars, Daniel Brian; Harding, Eric C.; Jennings, Christopher A.; Awe, Thomas James; Geissel, Matthias; Rovang, Dean C.; Smith, Ian C.; Chandler, Gordon A.; Cooper, Gary Wayne; Cuneo, Michael Edward; Harvey-Thompson, Adam James; Herrmann, Mark C.; Mark Harry Hess; Lamppa, Derek C.; Martin, Matthew R.; McBride, Ryan D.; Peterson, Kyle J.; Porter, John L.; Rochau, Gregory A.; Savage, Mark E.; Schroen, Diana G.; Stygar, William A.; Vesey, Roger Alan

    2015-04-29

    In this study, the magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 1012 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm3. In these experiments, up to 5 ×1010 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm2, this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 1010. An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source.

  1. Dopaminergic Therapy for Restless Legs Syndrome/Willis-Ekbom Disease.

    PubMed

    Zak, Rochelle S; Walters, Arthur S

    2015-09-01

    Dopaminergic therapies have been a mainstay of restless legs treatment and are endorsed as first-line therapies by multiple professional societies. This article summarizes the differences and similarities among the dopamine agonists with attention to pharmacology, efficacy, side effects, and dosing. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Modeling Human Performance in Restless Bandits with Particle Filters

    ERIC Educational Resources Information Center

    Yi, Sheng Kung M.; Steyvers, Mark; Lee, Michael

    2009-01-01

    Bandit problems provide an interesting and widely-used setting for the study of sequential decision-making. In their most basic form, bandit problems require people to choose repeatedly between a small number of alternatives, each of which has an unknown rate of providing reward. We investigate restless bandit problems, where the distributions of…

  3. [Restless Legs Syndrome : A Threat to the quality of life].

    PubMed

    Castaño-Cárcamo, Mauricio; Escobar-Cordoba, Franklin; Rey de Castro, Jorge

    2014-01-01

    Restless legs syndrome is a disorder associated with the imperative need to move the legs, starting at different times of day and it gets worse at night, relieved by activity, affecting the quality of life and sleep who sufferers it. Despite being a common disorder at any age, in adults with a prevalence of up to 10%, is not diagnosed by doctors and first level specialists that is why diagnostic and therapeutic interventions get delayed contributing to the perpetuation of symptoms and worsening quality of life. Since its diagnosis is purely clinical, getting familiar with this disorder is essential to ensure proper focus and thus rule out other diseases commonly confused with this one. Restless legs syndrome has a multi-factorial etiology that ranges from a genetic and hereditary, which are called primary restless legs syndrome, to its association with multiple pathologies, known as secondary restless legs syndrome. As for its management, drug therapy and non-drug therapy is aimed at symptom control, as its cure is not possible, although occasionally the condition can refer to later repeat in months or years.

  4. Clinical and polysomnographic features of patients with Restless Legs Syndrome.

    PubMed

    Mungan, Semra; Ozcan, Murat; Orhan, Gurdal; Titiz, Ayse; Arli, Berna; Koseoglu, Sabri; Ak, Fikri; Dere, Haci Huseyin

    2016-05-01

    To reveal clinical and polysomnographic features in patients treated for restless leg syndrome, and to examine the compatibility of sleep data and clinical features. The study was conducted at the Department of Neurology, Ankara Numune Training and Education Hospital, Ankara, Turkey, and comprised patients who presented to the outpatient clinic between January and July 2014 who were diagnosed with restless leg syndrome based on the International RestIess Leg Syndrome Study Group criteria. Patients underwent polysomnography test in spontaneous sleep in a single room. SPSS 18 was used for statistical analyses. Of the 18 patients, 13(72%)were females and 5(28%)were males. Overall mean age was 51.56±11.57years (range: 23-66 years). Fourteen (77.8%) patients reported insomnia; 10(55.5%) patients had excessive daytime sleepiness; 13(72.2%) reported snoring; and 3(17%) had apnoea. Mean International Restless Legs Syndrome Study Group Rating Scale score was 26.11±7.9 (range: 16-40).Mean Epworth Sleepiness Scale score was 9.17±5.1 (range: 0-20). Restless leg syndrome was more common in women and the most common complaint was insomnia.

  5. [Restless legs syndrome and diabetes mellitus: an accidental association?].

    PubMed

    Greco, Domenico

    2011-05-01

    Although limited in number, several studies have documented an increased prevalence of Restless Legs Syndrome (RLS) in type 2 diabetes. Polyneuropathy only partially explains the relation between the two disorders. This association could be due to the effects of a prolonged sleep loss: in increasing the probability of developing insulin-resistance and metabolic disturbances.

  6. Thermonuclear inverse magnetic pumping power cycle for stellarator reactors

    SciTech Connect

    Ho, D.D.M.; Kulsrud, R.M.

    1985-09-01

    A novel power cycle for direct conversion of alpha-particle energy into electricity is proposed for an ignited plasma in a stellarator reactor. The plasma column is alternately compressed and expanded in minor radius by periodic variation of the toroidal magnetic field strength. As a result of the way a stellarator is expected to work, the plasma pressure during expansion is greater than the corresponding pressure during compression. Therefore, negative work is done on the plasma during a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils, and direct electrical energy is obtained from this voltage. For a typical reactor, the average power obtained from this cycle (with a minor radius compression factor on the order of 50%) can be as much as 50% of the electrical power obtained from the thermonuclear neutrons without compressing the plasma. Thus, if it is feasible to vary the toroidal field strength, the power cycle provides an alternative scheme of energy conversion for a deuterium-tritium fueled reactor. The cycle may become an important method of energy conversion for advanced neutron-lean fueled reactors. By operating two or more reactors in tandem, the cycle can be made self-sustaining.

  7. Current drive for stability of thermonuclear plasma reactor

    NASA Astrophysics Data System (ADS)

    Amicucci, L.; Cardinali, A.; Castaldo, C.; Cesario, R.; Galli, A.; Panaccione, L.; Paoletti, F.; Schettini, G.; Spigler, R.; Tuccillo, A.

    2016-01-01

    To produce in a thermonuclear fusion reactor based on the tokamak concept a sufficiently high fusion gain together stability necessary for operations represent a major challenge, which depends on the capability of driving non-inductive current in the hydrogen plasma. This request should be satisfied by radio-frequency (RF) power suitable for producing the lower hybrid current drive (LHCD) effect, recently demonstrated successfully occurring also at reactor-graded high plasma densities. An LHCD-based tool should be in principle capable of tailoring the plasma current density in the outer radial half of plasma column, where other methods are much less effective, in order to ensure operations in the presence of unpredictably changes of the plasma pressure profiles. In the presence of too high electron temperatures even at the periphery of the plasma column, as envisaged in DEMO reactor, the penetration of the coupled RF power into the plasma core was believed for long time problematic and, only recently, numerical modelling results based on standard plasma wave theory, have shown that this problem should be solved by using suitable parameter of the antenna power spectrum. We show here further information on the new understanding of the RF power deposition profile dependence on antenna parameters, which supports the conclusion that current can be actively driven over a broad layer of the outer radial half of plasma column, thus enabling current profile control necessary for the stability of a reactor.

  8. Evidence of Spreading Layer Emission in a Thermonuclear Superburst

    NASA Astrophysics Data System (ADS)

    Koljonen, K. I. I.; Kajava, J. J. E.; Kuulkers, E.

    2016-10-01

    When a neutron star (NS) accretes matter from a companion star in a low-mass X-ray binary, the accreted gas settles onto the stellar surface through a boundary/spreading layer. On rare occasions the accumulated gas undergoes a powerful thermonuclear superburst powered by carbon burning deep below the NS atmosphere. In this paper, we apply the non-negative matrix factorization spectral decomposition technique to show that the spectral variations during a superburst from 4U 1636-536 can be explained by two distinct components: (1) the superburst emission characterized by a variable temperature blackbody radiation component and (2) a quasi-Planckian component with a constant, ˜2.5 keV, temperature varying by a factor of ˜15 in flux. The spectrum of the quasi-Planckian component is identical in shape and characteristics to the frequency-resolved spectra observed in the accretion/persistent spectrum of NS low-mass X-ray binaries and agrees well with the predictions of the spreading layer model by Inogamov & Sunyaev. Our results provide yet more observational evidence that superbursts—and possibly also normal X-ray bursts—induce changes in the disc-star boundary.

  9. Poloidal flux linkage requirements for the International Thermonuclear Experimental Reactor

    SciTech Connect

    Jardin, S.C.; Kessel, C.; Pomphrey, N.

    1994-01-01

    We have applied two computational models to calculate the poloidal flux linkage requirements for the current ramp-up and for the flattop phase of the proposed International Thermonuclear Experimental Reactor (ITER). For the current ramp-up phase, we have used the TSC code to simulate the entire current ramp-up period as described in the TAC-3 Physics Report. We have extended the time of the simulation to cover the full current penetration time, that is, until the loop voltage is a constant throughout the plasma. Sensitivity studies have been performed with respect to current ramp-up time, impurity concentration, and to the time of onset of auxiliary heating. We have also used a steady state plasma equilibrium code that has the constant loop voltage constraint built in to survey the dependence of the steady state loop-voltage on the density and temperature profiles. This calculation takes into account the plasma bootstrap current contribution, including non-circular and collisional corrections. The results can be displayed as contours of the loop-voltage on a POPCON like diagram.

  10. Thermonuclear dynamo inside ultracentrifuge with supersonic plasma flow stabilization

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2016-01-01

    Einstein's general theory of relativity implies the existence of virtual negative masses in the rotational reference frame of an ultracentrifuge with the negative mass density of the same order of magnitude as the positive mass density of a neutron star. In an ultracentrifuge, the repulsive gravitational field of this negative mass can simulate the attractive positive mass of a mini-neutron star, and for this reason can radially confine a dense thermonuclear plasma placed inside the centrifuge, very much as the positive mass of a star confines its plasma by its own attractive gravitational field. If the centrifuge is placed in an externally magnetic field to act as the seed field of a magnetohydrodynamic generator, the configuration resembles a magnetar driven by the release of energy through nuclear fusion, accelerating the plasma to supersonic velocities, with the magnetic field produced by the thermomagnetic Nernst effect insulating the hot plasma from the cold wall of the centrifuge. Because of the supersonic flow and the high plasma density the configuration is stable.

  11. Thermonuclear runaways in thick hydrogen rich envelopes of neutron stars

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Kenyon, S.; Truran, J. W.; Sparks, W. M.

    1982-01-01

    A Lagrangian, fully implicit, one-dimensional hydrodynamic computer code is used to evolve thermonuclear runaways in the accreted hydrogen-rich envelopes of 1.0-solar-mass neutron stars with radii of 10 km and 20 km. The simulations produce outbursts lasting from approximately 750 seconds to approximately one week. The peak effective temperatures and luminosities are 2.6 x 10 to the 7th K and 8 x 10 to the 4th solar luminosities for the 10 km study and 5.3 x 10 to the 6th K and 600 solar luminosities for the 20 km study. It is found that hydrodynamic expansion on the 10 km neutron star produced a precursor lasting approximately 0.0001 second. The study assumes that the bursters and transient X-ray sources occur as a result of mass transfer from a secondary onto a neutron star in a fashion analogous to the nova phenomena. The peak temperatures and luminosities are found to be inversely proportional to the radius of the neutron stars and the calculations here, together with those in the literature, indicate that the actual radii of most neutron stars must be closer to 10 km than 20 km.

  12. Thermonuclear dynamo inside ultracentrifuge with supersonic plasma flow stabilization

    SciTech Connect

    Winterberg, F.

    2016-01-15

    Einstein's general theory of relativity implies the existence of virtual negative masses in the rotational reference frame of an ultracentrifuge with the negative mass density of the same order of magnitude as the positive mass density of a neutron star. In an ultracentrifuge, the repulsive gravitational field of this negative mass can simulate the attractive positive mass of a mini-neutron star, and for this reason can radially confine a dense thermonuclear plasma placed inside the centrifuge, very much as the positive mass of a star confines its plasma by its own attractive gravitational field. If the centrifuge is placed in an externally magnetic field to act as the seed field of a magnetohydrodynamic generator, the configuration resembles a magnetar driven by the release of energy through nuclear fusion, accelerating the plasma to supersonic velocities, with the magnetic field produced by the thermomagnetic Nernst effect insulating the hot plasma from the cold wall of the centrifuge. Because of the supersonic flow and the high plasma density the configuration is stable.

  13. Thermonuclear Burst Observations for Model Comparisons: A Reference Sample

    NASA Astrophysics Data System (ADS)

    Galloway, Duncan K.; Goodwin, Adelle J.; Keek, Laurens

    2017-04-01

    We present observations of thermonuclear (type-I) X-ray bursts, selected for comparison with numerical models. We provide examples of four distinct cases of ignition: He-ignition in mixed H/He fuel (case 1); He-ignition in pure He fuel, following exhaustion of accreted H by steady burning (case 2); ignition in (almost) pure He accumulated from an evolved donor in an ultracompact system; and a superburst, thought to arise from ignition of carbon fuel produced as a by-product of H/He bursts. For regular bursts, we measured the recurrence time and calculated averaged burst profiles from RXTE observations. We also estimated the recurrence time for pairs of bursts, including those observed during a transient outburst, modelled using a numerical ignition code. For each example we list the burst properties including recurrence time, fluence, peak flux, the persistent flux level (and inferred accretion rate), and the ratio of persistent flux to fluence. In the accompanying material, we provide a bolometric lightcurve for each burst, determined from time-resolved spectral analysis. Along with the inferred or adopted parameters for each burst system, including distance, surface gravity, and redshift, these data are suggested as suitable test cases for ignition models.

  14. Divertor impurity monitor for the International Thermonuclear Experimental Reactor

    NASA Astrophysics Data System (ADS)

    Sugie, T.; Ogawa, H.; Nishitani, T.; Kasai, S.; Katsunuma, J.; Maruo, M.; Ebisawa, K.; Ando, T.; Kita, Y.

    1999-01-01

    The divertor impurity monitoring system of the International Thermonuclear Experimental Reactor has been designed. The main functions of this system are to identify impurity species and to measure the two-dimensional distributions of the particle influxes in the divertor plasmas. The wavelength range is 200-1000 nm. The viewing fans are realized by molybdenum mirrors located in the divertor cassette. With additional viewing fans seeing through the gap between the divertor cassettes, the region approximately from the divertor leg to the x point will be observed. The light from the divertor region passes through the quartz windows on the divertor port plug and the cryostat, and goes through the dog-leg optics in the biological shield. Three different type of spectrometers: (i) survey spectrometers for impurity species monitoring, (ii) filter spectrometers for the particle influx measurement with the spatial resolution of 10 mm and the time resolution of 1 ms, and (iii) high dispersion spectrometers for high resolution wavelength measurements are designed. These spectrometers are installed just behind the biological shield (for λ<450 nm) to prevent the transmission loss in fiber and in the diagnostic room (for λ⩾450 nm) from the point of view of accessibility and flexibility. The optics have been optimized by a ray trace analysis. As a result, 10-15 mm spatial resolution will be achieved in all regions of the divertor.

  15. Wideband Heterodyne QWIP Receiver Development for Thermonuclear Fusion Measurements

    SciTech Connect

    Bennett, C.A.; Buchanan, M.; Hutchinson, D.P.; Liu, H.C.; Richards, R.K.; Simpson, M.L.

    1998-11-01

    Oak Ridge National Laboratory (ORNL) has been developing heterodyne receivers for plasma diagnostic applications for over 20 years. One area of this work has been the development of a diagnostic system for the measurement of the energy of alpha particles created in a thermonuclear fusion reactor. These particles originate with an energy of 3.5 MeV and cool to the thermal energy of the plasma (around 15 keV) after several seconds. To measure the velocity distribution of these alpha particles, a Thomson scattering diagnostic is under development based on a high power CO{sub 2} laser at 10 microns with a heterodyne receiver. The Doppler shift generated by Thomson scattering of the alpha particles requires a wideband heterodyne receiver (greater than 10 GHz). Because Mercury-Cadimum-Telluride (MCT) detectors are limited to a bandwidth of approximately 2 GHz, a Quantum Well Infrared Photodetector (QWIP) detector was obtained from the National Research Council of Canada (NRC) and evaluated for its heterodyne performance using the heterodyne testing facility developed at ORNL.

  16. Detection of burning ashes from thermonuclear X-ray bursts

    NASA Astrophysics Data System (ADS)

    Kajava, J. J. E.; Nättilä, J.; Poutanen, J.; Cumming, A.; Suleimanov, V.; Kuulkers, E.

    2017-01-01

    When neutron stars (NS) accrete gas from low-mass binary companions, explosive nuclear burning reactions in the NS envelope fuse hydrogen and helium into heavier elements. The resulting thermonuclear (type-I) X-ray bursts produce energy spectra that are fit well with black bodies, but a significant number of burst observations show deviations from Planck spectra. Here we present our analysis of RXTE/PCA observations of X-ray bursts from the NS low-mass X-ray binary HETE J1900.1-2455. We have discovered that the non-Planckian spectra are caused by photoionization edges. The anticorrelation between the strength of the edges and the colour temperature suggests that the edges are produced by the nuclear burning ashes that have been transported upwards by convection and become exposed at the photosphere. The atmosphere model fits show that occasionally the photosphere can consist entirely of metals, and that the peculiar changes in blackbody temperature and radius can be attributed to the emergence and disappearance of metals in the photosphere. As the metals are detected already in the Eddington-limited phase, it is possible that a radiatively driven wind ejects some of the burning ashes into the interstellar space.

  17. Nucleosynthesis in type Ia supernovae driven by asymmetric thermonuclear ignition

    NASA Astrophysics Data System (ADS)

    Maeda, Keiichi

    2012-11-01

    Type Ia Supernovae (SNe Ia) are believed to be thermonuclear explosions of a white dwarf. They can be used as mature cosmological standardized candles, leading to the discovery of the accelerating expansion of the Universe. However, the explosion mechanism has not yet been fully clarified. In this paper, we first present nucleosynthetic features of a leading explosion scenario, namely a delayed-detonation scenario. Based on this, we propose a new and strong observational constraint on the explosion mechanism through emission lines from neutron-rich Fe-peaks. Especially, we show that an asymmetry in the explosion is likely a generic feature. We further argue that the diversity arising from various viewing angles can be an origin of observational diversities of SNe Ia seen in their spectral features (suspected possible biases in cosmology) and colors (related to the extinction estimate in cosmology). Using these new insights could open up a possibility of using SNe Ia as more precise distance indicators than currently employed.

  18. Focused Study of Thermonuclear Bursts on Neutron Stars

    NASA Astrophysics Data System (ADS)

    Chenevez, Jérôme

    2009-05-01

    X-ray bursters form a class of Low Mass X-Ray Binaries where accreted material from a donor star undergoes rapid thermonuclear burning in the surface layers of a neutron star. The flux released can temporarily exceed the Eddington limit and drive the photosphere to large radii. Such photospheric radius expansion bursts likely eject nuclear burning ashes into the interstellar medium, and may make possible the detection of photoionization edges. Indeed, theoretical models predict that absorption edges from 58Fe at 9.2 keV, 60Zn and 62Zn at 12.2 keV should be detectable by the future missions Simbol-X and NuSTAR. A positive detection would thus probe the nuclear burning as well as the gravitational redshift from the neutron star. Moreover, likely observations of atomic X-ray spectral components reflected from the inner accretion disk have been reported. The high spectral resolution capabilities of the focusing X-ray telescopes may therefore make possible to differentiate between the potential interpretations of the X-ray bursts spectral features.

  19. Nucleosynthesis in type Ia supernovae driven by asymmetric thermonuclear ignition

    SciTech Connect

    Maeda, Keiichi

    2012-11-12

    Type Ia Supernovae (SNe Ia) are believed to be thermonuclear explosions of a white dwarf. They can be used as mature cosmological standardized candles, leading to the discovery of the accelerating expansion of the Universe. However, the explosion mechanism has not yet been fully clarified. In this paper, we first present nucleosynthetic features of a leading explosion scenario, namely a delayed-detonation scenario. Based on this, we propose a new and strong observational constraint on the explosion mechanism through emission lines from neutron-rich Fe-peaks. Especially, we show that an asymmetry in the explosion is likely a generic feature. We further argue that the diversity arising from various viewing angles can be an origin of observational diversities of SNe Ia seen in their spectral features (suspected possible biases in cosmology) and colors (related to the extinction estimate in cosmology). Using these new insights could open up a possibility of using SNe Ia as more precise distance indicators than currently employed.

  20. High energy components and collective modes in thermonuclear plasmas

    SciTech Connect

    Coppi, B.; Cowley, S.; Detragiache, P.; Kulsrud, R.; Pegoraro, F.

    1986-02-01

    The theory of a class of collective modes of a thermonuclear magnetically confined plasma, with frequencies in the range of the ion cyclotron frequency and of its harmonics, is presented. These modes can be excited by their resonant cyclotron interaction with a plasma component of relatively high energy particles characterized by a strongly anisotropic distribution in velocity space. Normal modes that are spatially localized by the inhomogeneity of the plasma density are found. This ensures that the energy gained by their resonant interaction is not convected away. The mode spatial localization can be significantly altered by the magnetic field inhomogeneity for a given class of plasma density profiles. Special attention is devoted to the case of a spin polarized plasma, where the charged products of fusion reactions are anisotropically distributed. We show that for the mode of polarization that enhances nuclear reaction rates the tritium will be rapidly depolarized to toroidal configurations with relatively mild gradients of the confining magnetic field. 18 refs., 9 figs.

  1. Thermonuclear processes on accreting neutron stars - A systematic study

    NASA Technical Reports Server (NTRS)

    Ayasli, S.; Joss, P. C.

    1982-01-01

    A series of model calculations for the evolution of the surface layers of an accreting neutron star is carried out. The neutron star mass, radius, core temperature, and surface magnetic field strength are systematically varied, as are the accretion rate onto the neutron star surface and the metallicity of the accreting matter, in order to determine the effects of these parameters on the properties of thermonuclear flashes in the surface layers and the emitted X-ray bursts that result from such flashes. The core temperatures required for thermal equilibrium are found to be approximately a factor of 2 lower than estimated in earlier work. Owing to the effects of the gravitational redshift, the emitted X-ray bursts have lower peak luminosities and longer durations than those calculated in the Newtonian approximation. The entrainment of hydrogen into helium flashes can cause the flashes to exhibit a rather wide range of observable effects and can decrease by a factor of more than 2 the ratio of persistent accretion-driven luminosity to time-averaged burst luminosity emitted by the neutron star.

  2. Optimized heavy ion beam probing for International Thermonuclear Experimental Reactor

    NASA Astrophysics Data System (ADS)

    Melnikov, A. V.; Eliseev, L. G.

    1999-01-01

    The international workgroup developed the conceptual design of a heavy ion beam probe (HIBP) diagnostics for International Thermonuclear Experimental Reactor (ITER), which is intended for measurements of the plasma potential profile in a gradient area. Now we optimized it by the accurate analysis of the probing trajectories and variation of positions of the injection and detection points. Optimization allows us to reduce the energy of Tl+ beam from 5.6 to 3.4 MeV for standard ITER regime. The detector line starting at the plasma edge towards the center can get an outer part of the horizontal radial potential profile by variation of the energy. The observed radial interval is slightly increased up to 0.76<ρ<1 with respect to initial version 0.8<ρ<1, that allows to cover the region of the density gradient more reliably. Almost double reduction of the beam energy is a critical point. Thus we can significantly decrease the sizes of the accelerator and energy analyzer, the cost of the equipment, and impact of the diagnostics to the machine. Therefore the optimized HIBP design can be realized in ITER.

  3. Restless Legs Syndrome in a Nigerian Elderly Population

    PubMed Central

    Fawale, Michael B.; Ismaila, Isiaka Alani; Mustapha, Adekunle F.; Komolafe, Morenikeji A.; Adedeji, Tewogbade A.

    2016-01-01

    Study Objectives: The prevalence of restless legs syndrome (RLS) is highest in the elderly in Caucasian populations; the prevalence of RLS in elderly Africans is not known. This study aimed at determining the frequency and associations of RLS in a Nigerian elderly population. Methods: The study population comprised of 633 consecutive elderly individuals aged 65–105 years attending the general outpatient clinic of the State Hospital, Ilesa, for minor complaints and routine check-up. The diagnosis of RLS was made using the 2003 minimal criteria of the International Restless Legs Syndrome Study Group. Relevant sociodemographic and clinical data, including sleep duration, were also obtained. Results: Restless legs syndrome was found in 3.5% of the study population with a male-female ratio of 2:1. There was no significant age (p = 0.427) or gender (p = 0.178) influence on the prevalence of RLS except in the 75- to 84-year age group where there was significant male preponderance (p = 0.044). A strong independent association between RLS and sleep duration (OR, 3.229; 95% CI, 1.283–8.486; p = 0.013) and past history of head injury (OR, 4.691; 95% CI, 1.750–12.577; p = 0.002) was found. Conclusions: Our finding support previous reports of a possible lower prevalence of RLS in Africans. Restless legs syndrome independently increases the odds of habitual sleep curtailment in elderly individuals. Head injury may be a risk factor for future RLS; this requires further investigation as indirect evidence for a possible link between RLS and traumatic brain injury exists. Citation: Fawale MB, Ismaila IA, Mustapha AF, Komolafe MA, Adedeji TA. Restless legs syndrome in a Nigerian elderly population. J Clin Sleep Med 2016;12(7):965–972. PMID:27070251

  4. Ropinirole: new indication. Restless legs: disproportionate adverse effects.

    PubMed

    2006-10-01

    (1) The restless legs syndrome consists of unpleasant sensory and motor symptoms of varying intensity in the lower limbs. Symptoms occur at rest, seated or lying down, are more intense in the evening and at night, and are relieved by moving the limb. This syndrome does not cause serious physical complications. When sleep disturbances occur, non drug methods should be tried first. (2) Ropinirole is a dopaminergic agonist initially marketed for the treatment of Parkinson's disease. It is the first drug to be approved for restless legs syndrome in France. (3) Three double-blind randomised placebo-controlled trials with similar designs showed minimal differences on a composite rating scale. After 12 weeks of treatment, ropinirole led to an improvement of about 3 points on a 40-point scale compared with placebo. (4) A 12-week double-blind randomised controlled trial and including patients who had "responded" to ropinirole showed a lower relapse rate in the group that continued to use ropinirole (32.6%) instead of switching to placebo (57.8%). However, we do not know if this was because of continued drug efficacy or a rebound effect in the placebo group. (5) The adverse effects of ropinirole in patients with restless legs syndrome had already been observed in the treatment of Parkinson's disease, and included nausea, vomiting, drowsiness, a sudden urge to sleep, syncope, hypotension, and hallucinations. (6) An increase in the severity of restless legs symptoms, typically seen with levodopa, was not evaluated in clinical trials of ropinirole. Some cases have nevertheless been reported. They describe the appearance of symptoms increasingly early in the evening, then in the afternoon, or as a rebound effect in the morning or the latter part of the night. Their intensity increases and can affect other parts of the body. (7) In practice, ropinirole has a negative risk-benefit balance in restless legs syndrome, which is a minor health disorder.

  5. Restless Legs Syndrome and Cognitive Function: A Population-based Cross-sectional Study.

    PubMed

    Rist, Pamela M; Elbaz, Alexis; Dufouil, Carole; Tzourio, Christophe; Kurth, Tobias

    2015-09-01

    Restless legs syndrome has been speculated to be linked to cognitive impairment through vascular risk factors or through its effect on sleep deprivation. Previous studies on the association between restless legs syndrome and cognitive function have been inconclusive. We performed a cross-sectional analysis of the association between restless legs syndrome and cognitive function using data from a large population-based study of elderly individuals residing in France. We used information from 2070 individuals from the Dijon, France center of the Three-City study who had available information on restless legs syndrome and cognitive functioning measures. Restless legs syndrome was assessed using the 4 minimal diagnostic criteria of the International Restless Legs Study Group. During the same wave in which restless legs syndrome status was assessed, cognitive functions also were assessed using 4 tests: Isaacs' test of verbal/category fluency, the Benton Visual Retention Test, the Trail Making Test B, and the Mini-Mental State Examination. We created a summary global cognitive score by summing the z scores for the 4 tests and used analysis of covariance to explore the association between restless legs syndrome and cognitive function. We did not observe any statistically significant differences in any cognitive z-score between those with restless legs syndrome and those without restless legs syndrome. The mean global z-score after multivariate adjustment was -0.003 (SE 0.173) for those with restless legs syndrome and -0.007 (SE 0.129) for those without restless legs syndrome (P-value = .98). Data from this large, population-based study do not suggest that restless legs syndrome is associated with prevalent cognitive deficits in elderly individuals. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. The black hole candidate Swift J1753.5-0127 is back in quiescence

    NASA Astrophysics Data System (ADS)

    Zhang, Guobao; Russell, David M.; Bernardini, Federico; Gelfand, Joseph D.; Lewis, Fraser

    2017-07-01

    We report on new optical observations showing that after a period of intense activity at the end of its 11-year long outburst, the black hole candidate Swift J1753.5-0127 appears to be back in quiescence.

  7. Passive degassing during quiescence: a trigger of volcanic unrest

    NASA Astrophysics Data System (ADS)

    Girona, Társilo; Costa, Fidel; Newhall, Chris

    2014-05-01

    . Thus, our results suggest that many of the unrest episodes at openly-degassing volcanoes are causally linked to the gas emitted during quiescence. We propose that degassing-induced depressurization is a trigger of different physical processes, such as magma replenishment and fractures, which can culminate in unrest episodes and eventual eruption. This study opens the possibility to use the total mass of gas released during quiescence as a new proxy to anticipate unrest at openly-degassing volcanoes.

  8. Effects of prolonged quiescence on neuclei and chromatin of WI-38 fibroblasts.

    PubMed

    Rossini, M; Lin, J C; Baserga, R

    1976-05-01

    DNA synthesis and cell division are markedly reduced in confluent mono-layers of WI-38 diploid fibroblasts, but resume again if the depleted medium is replaced by fresh medium containing 10% fetal calf serum. If the cells are kept quiescent for prolonged periods of time after confluence (1 or 2 weeks), the fraction of cells that can be stimulated to proliferate by fresh serum decreases and the length of the prereplicative phase increases. The template activity of isolated nuclei decreases with increasing time of quiescence, and parallel changes occur in chromatin as evidenced by circular dichroism spectra and capacity to bind the intercalating dye, ethidium bromide. When WI-38 cells are stimulated to proliferate after prolonged quiescence, the increase in template activity of nuclei is delayed by several hours in comparison to cells stimulated after short periods of quiescence. Two distinct steps, both requiring serum, can be identified in the prereplicative phase of cells stimulated to proliferative after prolonged quiescence. We interpret the results as indicating that, during prolonged quiescence, WI-38 fibroblasts go into a deeper GO state from which they can be rescued only after prolonged stimulation. In this respect, prolonged quiescence may bear some resemblance to the process of aging.

  9. The role of brain natriuretic peptide in maintaining myometrial quiescence during pregnancy.

    PubMed

    Carvajal, Jorge A

    2014-03-01

    Myometrial quiescence is a physiological stage of the myometrium during pregnancy. It is a period of active relaxation of the myometrial smooth muscle cells; myometrial quiescence is responsible for maintaining pregnancy. The precise mechanisms underlying myometrial quiescence have not been completely elucidated, although many mediators and cellular pathways have been described as playing a role. Fetal membranes (chorion and amnion) produce and release one or more substances that inhibit myometrial contractions, playing a central role in the maintenance of myometrial quiescence. Brain natriuretic peptide (BNP) is more potent than any other natriuretic peptide in inhibiting myometrial contractions in vitro. Brain natriuretic peptide is produced by the chorion and amnion, mainly during myometrial quiescence, and decreasing towards the end of pregnancy. Production of BNP is reduced in fetal membranes obtained from women in preterm labour. It is postulated that BNP, acting in a paracrine fashion, plays a key role in the maintaining myometrial quiescence and, therefore, controlling the duration of pregnancy. Furthermore, it is postulated that a premature decrease of BNP production by the fetal membranes may cause preterm labour and preterm birth.

  10. A RADIO-LOUD MAGNETAR IN X-RAY QUIESCENCE

    SciTech Connect

    Levin, Lina; Bailes, Matthew; Bhat, N. D. Ramesh; Burke-Spolaor, Sarah; Van Straten, Willem; Bates, Samuel; Kramer, Michael; Stappers, Ben; Burgay, Marta; D'Amico, Nichi; Milia, Sabrina; Possenti, Andrea; Rea, Nanda

    2010-09-20

    As part of a survey for radio pulsars with the Parkes 64 m telescope, we have discovered PSR J1622-4950, a pulsar with a 4.3 s rotation period. Follow-up observations show that the pulsar has the highest inferred surface magnetic field of the known radio pulsars (B {approx}3 x 10{sup 14} G), and it exhibits significant timing noise and appears to have an inverted spectrum. Unlike the vast majority of the known pulsar population, PSR J1622-4950 appears to switch off for many hundreds of days and even in its on-state exhibits extreme variability in its flux density. Furthermore, the integrated pulse profile changes shape with epoch. All of these properties are remarkably similar to the only two magnetars previously known to emit radio pulsations. The position of PSR J1622-4950 is coincident with an X-ray source that, unlike the other radio pulsating magnetars, was found to be in quiescence. We conclude that our newly discovered pulsar is a magnetar-the first to be discovered via its radio emission.

  11. Herschel observations of Circinus X-1 during outburst and quiescence

    SciTech Connect

    Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle; Fost, Tyler E-mail: dawn@ipac.caltech.edu E-mail: tyler.fost@gmail.com

    2014-07-01

    We have used the Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging REceiver instruments on the Herschel Space Observatory to observe Cir X-1 both in and out of outburst. We detected Cir X-1 during outburst at 70 μm. Unfortunately, a cold background source dominates Cir X-1 at longer wavelengths. We have assembled optical and infrared (IR) data for Cir X-1 to model its spectral energy distribution (SED) in both quiescence and outburst and find that in both states it is consistent with a heavily reddened, 10,000 K blackbody. We believe this behavior is completely consistent with previous suggestions that these outbursts are due to accretion disk events, not unlike those of dwarf novae. To explore the behavior of other low-mass X-ray binaries with reported synchrotron jets, we have extracted and/or compiled optical and near- and mid-IR data sets for five such systems to construct their SEDs. The Z-source GX 349+2 and the black hole system GRS 1915+105 have strong and variable mid-IR excesses that suggest synchrotron emission. The other Z-sources have rather weak (or no) IR excesses that can be explained as reddened blackbody spectra with the addition of either synchrotron or bremsstrahlung components.

  12. Electromagnetic Spindown of a Transient Accreting Millisecond Pulsar During Quiescence

    NASA Astrophysics Data System (ADS)

    Melatos, A.; Mastrano, A.

    2016-02-01

    The measured spindown rates in quiescence of the transient accreting millisecond pulsars IGR J00291+5934, XTE J1751-305, SAX J1808.4-3658, and Swift J1756.9-2508 have been used to estimate the magnetic moments of these objects assuming standard magnetic dipole braking. It is shown that this approach leads to an overestimate if the amount of residual accretion is enough to distort the magnetosphere away from a force-free configuration through magnetospheric mass loading or crushing, so that the lever arm of the braking torque migrates inside the light cylinder. We derive an alternative spindown formula and calculate the residual accretion rates where the formula is applicable. As a demonstration we apply the alternative spindown formula to produce updated magnetic moment estimates for the four objects above. We note that based on current uncertain observations of quiescent accretion rates, magnetospheric mass loading and crushing are neither firmly indicated nor ruled out in these four objects. Because quiescent accretion rates are not measured directly (only upper limits are placed), without more data it is impossible to be confident about whether the thresholds for magnetospheric mass loading or crushing are reached or not.

  13. ELECTROMAGNETIC SPINDOWN OF A TRANSIENT ACCRETING MILLISECOND PULSAR DURING QUIESCENCE

    SciTech Connect

    Melatos, A.; Mastrano, A. E-mail: alpham@unimelb.edu.au

    2016-02-10

    The measured spindown rates in quiescence of the transient accreting millisecond pulsars IGR J00291+5934, XTE J1751–305, SAX J1808.4–3658, and Swift J1756.9–2508 have been used to estimate the magnetic moments of these objects assuming standard magnetic dipole braking. It is shown that this approach leads to an overestimate if the amount of residual accretion is enough to distort the magnetosphere away from a force-free configuration through magnetospheric mass loading or crushing, so that the lever arm of the braking torque migrates inside the light cylinder. We derive an alternative spindown formula and calculate the residual accretion rates where the formula is applicable. As a demonstration we apply the alternative spindown formula to produce updated magnetic moment estimates for the four objects above. We note that based on current uncertain observations of quiescent accretion rates, magnetospheric mass loading and crushing are neither firmly indicated nor ruled out in these four objects. Because quiescent accretion rates are not measured directly (only upper limits are placed), without more data it is impossible to be confident about whether the thresholds for magnetospheric mass loading or crushing are reached or not.

  14. Restless legs syndrome and periodic leg movements in patients with movement disorders: Specific considerations.

    PubMed

    Högl, Birgit; Stefani, Ambra

    2017-05-01

    Restless legs syndrome is a frequent neurological disorder with potentially serious and highly distressing treatment complications. The role and potential implications of periodic leg movements during sleep range from being a genetic risk marker for restless legs syndrome to being a cardiovascular risk factor. The diagnosis of restless legs syndrome in patients with daytime movement disorders is challenging and restless legs syndrome needs to be differentiated from other sleep-related movement disorders. This article provides an update on the diagnosis of restless legs syndrome as an independent disorder and the role of periodic leg movements and reviews the association of restless legs syndrome with Parkinson's disease and other movement disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  15. Theory of supercompression of vapor bubbles and nanoscale thermonuclear fusion

    NASA Astrophysics Data System (ADS)

    Nigmatulin, Robert I.; Akhatov, Iskander Sh.; Topolnikov, Andrey S.; Bolotnova, Raisa Kh.; Vakhitova, Nailya K.; Lahey, Richard T.; Taleyarkhan, Rusi P.

    2005-10-01

    This paper provides the theoretical basis for energetic vapor bubble implosions induced by a standing acoustic wave. Its primary goal is to describe, explain, and demonstrate the plausibility of the experimental observations by Taleyarkhan et al. [Science 295, 1868 (2002); Phys. Rev. E 69, 036109 (2004)] of thermonuclear fusion for imploding cavitation bubbles in chilled deuterated acetone. A detailed description and analysis of these data, including a resolution of the criticisms that have been raised, together with some preliminary HYDRO code simulations, has been given by Nigmatulin et al. [Vestnik ANRB (Ufa, Russia) 4, 3 (2002); J. Power Energy 218-A, 345 (2004)] and Lahey et al. [Adv. Heat Transfer (to be published)]. In this paper a hydrodynamic shock (i.e., HYDRO) code model of the spherically symmetric motion for a vapor bubble in an acoustically forced liquid is presented. This model describes cavitation bubble cluster growth during the expansion period, followed by a violent implosion during the compression period of the acoustic cycle. There are two stages of the bubble dynamics process. The first, low Mach number stage, comprises almost all the time of the acoustic cycle. During this stage, the radial velocities are much less than the sound speeds in the vapor and liquid, the vapor pressure is very close to uniform, and the liquid is practically incompressible. This process is characterized by the inertia of the liquid, heat conduction, and the evaporation or condensation of the vapor. The second, very short, high Mach number stage is when the radial velocities are the same order, or higher, than the sound speeds in the vapor and liquid. In this stage high temperatures, pressures, and densities of the vapor and liquid take place. The model presented herein has realistic equations of state for the compressible liquid and vapor phases, and accounts for nonequilibrium evaporation/condensation kinetics at the liquid/vapor interface. There are interacting

  16. Theory of supercompression of vapor bubbles and nanoscale thermonuclear fusion

    SciTech Connect

    Nigmatulin, Robert I.; Akhatov, Iskander Sh.; Topolnikov, Andrey S.; Bolotnova, Raisa Kh.; Vakhitova, Nailya K.; Lahey, Richard T. Jr.; Taleyarkhan, Rusi P.

    2005-10-01

    This paper provides the theoretical basis for energetic vapor bubble implosions induced by a standing acoustic wave. Its primary goal is to describe, explain, and demonstrate the plausibility of the experimental observations by Taleyarkhan et al. [Science 295, 1868 (2002); Phys. Rev. E 69, 036109 (2004)] of thermonuclear fusion for imploding cavitation bubbles in chilled deuterated acetone. A detailed description and analysis of these data, including a resolution of the criticisms that have been raised, together with some preliminary HYDRO code simulations, has been given by Nigmatulin et al. [Vestnik ANRB (Ufa, Russia) 4, 3 (2002); J. Power Energy 218-A, 345 (2004)] and Lahey et al. [Adv. Heat Transfer (to be published)]. In this paper a hydrodynamic shock (i.e., HYDRO) code model of the spherically symmetric motion for a vapor bubble in an acoustically forced liquid is presented. This model describes cavitation bubble cluster growth during the expansion period, followed by a violent implosion during the compression period of the acoustic cycle. There are two stages of the bubble dynamics process. The first, low Mach number stage, comprises almost all the time of the acoustic cycle. During this stage, the radial velocities are much less than the sound speeds in the vapor and liquid, the vapor pressure is very close to uniform, and the liquid is practically incompressible. This process is characterized by the inertia of the liquid, heat conduction, and the evaporation or condensation of the vapor. The second, very short, high Mach number stage is when the radial velocities are the same order, or higher, than the sound speeds in the vapor and liquid. In this stage high temperatures, pressures, and densities of the vapor and liquid take place. The model presented herein has realistic equations of state for the compressible liquid and vapor phases, and accounts for nonequilibrium evaporation/condensation kinetics at the liquid/vapor interface. There are interacting

  17. SUPER-EDDINGTON FLUXES DURING THERMONUCLEAR X-RAY BURSTS

    SciTech Connect

    Boutloukos, Stratos; Miller, M. Coleman; Lamb, Frederick K.

    2010-09-01

    It has been known for nearly three decades that the energy spectra of thermonuclear X-ray bursts are often well fit by Planck functions with temperatures so high that they imply a super-Eddington radiative flux at the emitting surface, even during portions of bursts when there is no evidence of photospheric radius expansion. This apparent inconsistency is usually set aside by assuming that the flux is actually sub-Eddington and that the fitted temperature is so high because the spectrum has been distorted by the energy-dependent opacity of the atmosphere. Here we show that the spectra predicted by currently available conventional atmosphere models appear incompatible with the highest precision measurements of burst spectra made using the Rossi X-ray Timing Explorer, such as during the 4U 1820-30 superburst and a long burst from GX 17+2. In contrast, these measurements are well fit by Bose-Einstein spectra with high temperatures and modest chemical potentials. Such spectra are very similar to Planck spectra. They imply surface radiative fluxes more than a factor of 3 larger than the Eddington flux. We find that segments of many other bursts from many sources are well fit by similar Bose-Einstein spectra, suggesting that the radiative flux at the emitting surface also exceeds the Eddington flux during these segments. We suggest that burst spectra can closely approximate Bose-Einstein spectra and have fluxes that exceed the Eddington flux because they are formed by Comptonization in an extended, low-density radiating gas supported by the outward radiation force and confined by a tangled magnetic field.

  18. Spontaneous Formation of Detonations by Turbulent Flames in Thermonuclear Supernovae

    NASA Astrophysics Data System (ADS)

    Poludnenko, Alexei Y.; Oran, E. S.

    2012-01-01

    Presently, the scenario best capable of explaining the observational properties of "normal" type Ia supernovae (SNIa), which are of primary importance for cosmology, is the delayed-detonation model. This model postulates that a subsonic thermonuclear deflagration, which originates close to the center of a Chandrasekhar-mass white dwarf (WD) in a single-degenerate binary system, transitions to a supersonic detonation (deflagration-to-detonation transition, or DDT) during the later stages of the explosion. Modern large-scale multidimensional simulations of SNIa cannot capture the DDT process and, thus, are forced to make two crucial assumptions, namely (a) that DDT does occur at some point, and (b) when and where it occurs. Significant progress has been made over the years in elucidating the nature of DDT in terrestrial confined systems with walls, obstacles, or pre-existing shocks. It remains unclear, however, whether and how a detonation can form in an unpressurized, unconfined system such as the interior of a WD. Here we show, through first-principles numerical simulations, that sufficiently fast, but subsonic, turbulent flames in such unconfined environments are inherently susceptible to DDT. The associated mechanism is based on the unsteady evolution of turbulent flames faster than the Chapman-Jouguet deflagrations and is qualitatively different from the traditionally suggested gradient (spontaneous reaction wave) model. It also does not require the formation of distributed flames. The proposed mechanism predicts the DDT density in SNIa to be 107 g/cm3, in agreement with the values previously found to give the best match with observations. This DDT mechanism opens the possibility for eliminating the transition density as a free parameter and, thus, for developing fully self-consistent global multidimensional SNIa models. This work was supported in part by the Naval Research Laboratory, the Air Force Office of Scientific Research, and by the Department of Defense

  19. Association between restless leg syndrom and slow coronary flow.

    PubMed

    Erden, İsmail; Çakcak Erden, Emine; Durmuş, Hacer; Tıbıllı, Hakan; Tabakçı, Mustafa; Kalkan, Mehmet Emin; Türker, Yasin; Akçakoyun, Mustafa

    2014-11-01

    Restless legs syndrome (RLS) is a common sleep disorder in which patients feel unpleasent leg sensations and urge to move the legs during rest, especially at night, and symptoms are improved by leg movement. Prior studies analyzing the associations between cardiovascular disease and restless legs syndrome has shown controversial results. The goal of the study was to estimate the relationship between restless legs syndrome and slow coronary flow (SCF). The present study was cross-sectional and observational and consists of 176 individuals who underwent coronary angiography and had angiographically normal coronary arteries of varying coronary flow rates. The study included 86 patients with isolated SCF and 90 control participants with normal coronary flow (NCF). RLS was assessed the day after the coronry flow was evaluated, using a self-administered questionnaire based on the International Restless Legs Study Group criteria. The following question was asked: "Do you have unpleasant leg sensations (like crawling, paraesthesia, or pain) combined with motor restlessness and an urge to move?" The possible responses were as follows: no, less than once/month, 2-4 times/month, 5-14 times/month, and 15 or more times per month. Those who answered that they had these feelings were asked the following two more questions: 1) "Do these symptoms occur only at rest and does moving improve them?" and 2) "Are these symptoms worsen in the evening/at night compared with the morning?" RLS is considered to be probable if the participant has answered "yes" for all three of the above questions, and has a frequency of ≥5 times/month. Student's t-test, Mann-Whitney U test, multiple logistic regression analysis were used for statistical analysis. The prevalence of restless legs syndrome was 48 (27%) and increased significantly with age. Patients with SCF have more likely had RLS than the control group (p<0.001). The age-adjusted prevalence odds of SCF were 3.11 times higher (95% CI: 1

  20. Vascular risk factors, cardiovascular disease and restless legs syndrome in men

    PubMed Central

    Winter, Anke C.; Berger, Klaus; Glynn, Robert J; Buring, Julie E.; Gaziano, J. Michael; Schürks, Markus; Kurth, Tobias

    2012-01-01

    Background Prevalences of vascular risk factors, cardiovascular disease and restless legs syndrome increase with age. Prior studies analyzing the associations between vascular risk factors, cardiovascular disease, and restless legs syndrome found controversial results. We therefore aim to evaluate the association between prevalent vascular risk factors, prevalent cardiovascular disease and restless legs syndrome. Methods We conducted a cross-sectional study among 22,786 participants of the US Physicians’ Health Studies I and II. Restless legs syndrome was classified according to the four minimal diagnostic criteria. Vascular risk factors and restless legs syndrome symptoms were self-reported. Prevalent cardiovascular disease events including major cardiovascular disease, stroke and myocardial infarction were confirmed by medical record review. Age- and multivariable-adjusted logistic regression models were used to evaluate the association between vascular risk factors, prevalent cardiovascular disease events and restless legs syndrome. Results The mean age of the cohort 67.8 years. Restless legs syndrome prevalence was 7.5% and increased significantly with age. Diabetes significantly increased the odds (OR: 1.41, 95%CI: 1.21–1.65), while frequent exercise (OR: 0.78, 95%CI: 0.67–0.91) and alcohol consumption of one or more drinks per day (OR: 0.80, 95%CI: 0.69–0.92) significantly reduced the odds of restless legs syndrome in multivariable-adjusted models. Prevalent stroke showed an increased multivariable-adjusted OR of 1.40 (1.05–1.86) while men with prevalent myocardial infarction had a decreased OR of 0.73 (0.55–0.97) for restless legs syndrome. Conclusions The restless legs syndrome prevalence among US male physicians is similar to men of the same age group in other western countries. A history of diabetes is the most consistent risk factor associated with restless legs syndrome. Prevalent stroke and myocardial infarction are related to restless legs

  1. Dopa responsive burning mouth syndrome: restless mouth syndrome or oral variant of restless legs syndrome?

    PubMed

    Prakash, Sanjay; Ahuja, Sunil; Rathod, Chirag

    2012-09-15

    Burning mouth syndrome (BMS) is an oral dysesthesia presenting as a burning sensation of the tongue and other oral and perioral mucosae. A painful symptomatology in different bodily regions (extraoral) may also be a common feature in patient with BMS. The management of BMS is challenging and there is no clear guideline for the management of idiopathic BMS. Herein, we describe a group of patients (5 patients) in whom symptoms of BMS responded to levodopa. In parallel, four patients fulfilled the criteria for restless legs syndrome (RLS). Family history of RLS was positive in two patients. We reviewed the literature and noted a marked overlap between BMS and RLS. Overlaps were noted in epidemiological profiles, pattern of clinical features and even in neurophysiological observations (alterations in the striatal dopaminergic system). We suggest that a subset of patients with BMS may be a phenotypic variant of RLS and a trial of dopaminergic drugs should be given in patients with BMS who has a history suggestive of RLS or in a patient who do not show a response to usual therapies for BMS.

  2. Sleep fragmentation and motor restlessness in a Drosophila model of Restless Legs Syndrome.

    PubMed

    Freeman, Amanda; Pranski, Elaine; Miller, R Daniel; Radmard, Sara; Bernhard, Doug; Jinnah, H A; Betarbet, Ranjita; Rye, David B; Sanyal, Subhabrata

    2012-06-19

    Restless Legs Syndrome (RLS), first chronicled by Willis in 1672 and described in more detail by Ekbom in 1945, is a prevalent sensorimotor neurological disorder (5%-10% in the population) with a circadian predilection for the evening and night. Characteristic clinical features also include a compelling urge to move during periods of rest, relief with movement, involuntary movements in sleep (viz., periodic leg movements of sleep), and fragmented sleep. Although the pathophysiology of RLS is unknown, dopaminergic neurotransmission and deficits in iron availability modulate expressivity. Genome-wide association studies have identified a polymorphism in an intronic region of the BTBD9 gene on chromosome 6 that confers substantial risk for RLS. Here, we report that loss of the Drosophila homolog CG1826 (dBTBD9) appreciably disrupts sleep with concomitant increases in waking and motor activity. We further show that BTBD9 regulates brain dopamine levels in flies and controls iron homeostasis through the iron regulatory protein-2 in human cell lines. To our knowledge, this represents the first reverse genetic analysis of a "novel" or heretofore poorly understood gene implicated in an exceedingly common and complex sleep disorder and the development of an RLS animal model that closely recapitulates all disease phenotypes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Restless legs syndrome: an underappreciated and distressing problem for haemodialysis patients.

    PubMed

    Chu, L; Chu, E; Dogra, G; Chakera, A

    2014-10-01

    Restless legs syndrome is a distressing condition that is more common in patients with end-stage renal failure. Despite the significant impact it has on quality of life and the documented association between restless legs syndrome and increased mortality, limited data regarding the epidemiology of restless legs syndrome in Australian dialysis patients are available. We report a prospective study that assessed the prevalence and factors associated with restless legs syndrome in an in-centre haemodialysis population. © 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.

  4. [A case of Parkinson's disease following restless genial sensation].

    PubMed

    Sawamura, Masanori; Toma, Keiichiro; Unai, Yuki; Sekiya, Tomoko; Nishinaka, Kazuhito; Udaka, Fukashi

    2015-01-01

    A 62-year-old woman experienced uncomfortable genial sensation in 2010. Her uncomfortable sensation was exacerbated during rest at night and improved by walking. She exhibited short-stepped gait with postural disturbance and was diagnosed as suffering from Parkinson's disease (PD) in 2013. Administration of clonazepam and pramipexisole improved her uncomfortable genial sensation. In persistent genital arousal disorder (PGAD)/restless genial syndrome (RGS), abnormal genital sensation occurred without sexual desire, which was relieved by clonazepam administration. PGAD/RGS often coexists with restless legs syndrome (RLS). PGAD/RGS and RLS share common characteristics. This is the first case report of PD following PGAD/RGS, suggesting similar underlying mechanisms between PGAD/RGS and RLS associated with PD.

  5. Restless legs syndrome: demographics, presentation, and differential diagnosis.

    PubMed

    Hening, Wayne; Allen, Richard P; Tenzer, Penny; Winkelman, John W

    2007-09-01

    Restless legs syndrome (RLS) is a sensorimotor disorder characterized by a distressing urge to move the legs and sometimes other parts of the body. Diagnosis is based on clinical features that may be easily remembered with the mnemonic URGE: Urge to move, Rest induced, Gets better with activity, and Evening and night accentuation. RLS is common, its prevalence increases with age, and women are more frequently affected. The course is chronic with often severe sleep disruption, including periodic leg movements. Differential diagnosis includes disorders of restlessness and leg discomfort. Primary RLS is familial and likely to be genetic. Important causes of secondary RLS are end-stage renal disease, pregnancy, and iron deficiency. Every patient should be checked for iron status with a serum ferritin measurement.

  6. Passive degassing during quiescence as trigger of volcanic unrest

    NASA Astrophysics Data System (ADS)

    Girona, T.; Costa Rodriguez, F.; Newhall, C. G.; Taisne, B.

    2014-12-01

    Unravelling the mechanisms that trigger the ascent of magma to the surface is crucial for making progress towards improved eruption forecasts. This is especially important for persistent degassing volcanoes, like Etna (Italy) or Mayon (Philippines), since they are the most active sub-aerial volcanoes around the world. Their activity consists of quiescent periods, dominated by abundant passive gas emissions, that alternate with unrest episodes and eruptions occurring every few months or years. In this study, we wonder how passive degassing during quiescence can affect the eruptive dynamics of persistent degassing volcanoes. We have developed a new lumped parameter model that correlates the pressure of shallow magma reservoirs with the mean degassing rates measured with monitoring systems. The model accounts for the conduit-reservoir size, the viscoelastic properties of the crust, the exsolution and expansion of bubbles at depth, the magma density changes, and the connectivity between the shallow reservoir and deeper magma sources. Our theoretical analysis demonstrates that there are many realistic scenarios under which depressurizations between 1-10 MPa occur in only a few months or years, that is, within the inter-eruptive timescale of persistent degassing volcanoes. Our results are consistent with geophysical and geodetical observations at volcanoes like Llaima (Chile), Asama (Japan), Satsuma-Iwojima (Japan), and Masaya (Nicaragua), and suggest that degassing-induced depressurization could induce magma replenishment, sudden bubble expansion at depth, collapse of the crater floor, and fractures in the reservoir wall-rock. All these processes can, in turn, lead to new unrest episodes and eruption.

  7. Echocardiography as an indication of continuous-time cardiac quiescence

    NASA Astrophysics Data System (ADS)

    Wick, C. A.; Auffermann, W. F.; Shah, A. J.; Inan, O. T.; Bhatti, P. T.; Tridandapani, S.

    2016-07-01

    Cardiac computed tomography (CT) angiography using prospective gating requires that data be acquired during intervals of minimal cardiac motion to obtain diagnostic images of the coronary vessels free of motion artifacts. This work is intended to assess B-mode echocardiography as a continuous-time indication of these quiescent periods to determine if echocardiography can be used as a cost-efficient, non-ionizing modality to develop new prospective gating techniques for cardiac CT. These new prospective gating approaches will not be based on echocardiography itself but on CT-compatible modalities derived from the mechanics of the heart (e.g. seismocardiography and impedance cardiography), unlike the current standard electrocardiogram. To this end, echocardiography and retrospectively-gated CT data were obtained from ten patients with varied cardiac conditions. CT reconstructions were made throughout the cardiac cycle. Motion of the interventricular septum (IVS) was calculated from both echocardiography and CT reconstructions using correlation-based, deviation techniques. The IVS was chosen because it (1) is visible in echocardiography images, whereas the coronary vessels generally are not, and (2) has been shown to be a suitable indicator of cardiac quiescence. Quiescent phases were calculated as the minima of IVS motion and CT volumes were reconstructed for these phases. The diagnostic quality of the CT reconstructions from phases calculated from echocardiography and CT data was graded on a four-point Likert scale by a board-certified radiologist fellowship-trained in cardiothoracic radiology. Using a Wilcoxon signed-rank test, no significant difference in the diagnostic quality of the coronary vessels was found between CT volumes reconstructed from echocardiography- and CT-selected phases. Additionally, there was a correlation of 0.956 between the echocardiography- and CT-selected phases. This initial work suggests that B-mode echocardiography can be used as a

  8. Restless Legs Syndrome in a Nigerian Elderly Population.

    PubMed

    Fawale, Michael B; Ismail, Ishaq Alani; Mustapha, Adekunle F; Komolafe, Morenikeji A; Adedeji, Tewogbade A

    2016-07-15

    The prevalence of restless legs syndrome (RLS) is highest in the elderly in Caucasian populations; the prevalence of RLS in elderly Africans is not known. This study aimed at determining the frequency and associations of RLS in a Nigerian elderly population. The study population comprised of 633 consecutive elderly individuals aged 65-105 years attending the general outpatient clinic of the State Hospital, Ilesa, for minor complaints and routine check-up. The diagnosis of RLS was made using the 2003 minimal criteria of the International Restless Legs Syndrome Study Group. Relevant sociodemographic and clinical data, including sleep duration, were also obtained. Restless legs syndrome was found in 3.5% of the study population with a male-female ratio of 2:1. There was no significant age (p = 0.427) or gender (p = 0.178) influence on the prevalence of RLS except in the 75- to 84-year age group where there was significant male preponderance (p = 0.044). A strong independent association between RLS and sleep duration (OR, 3.229; 95% CI, 1.283-8.486; p = 0.013) and past history of head injury (OR, 4.691; 95% CI, 1.750-12.577; p = 0.002) was found. Our finding support previous reports of a possible lower prevalence of RLS in Africans. Restless legs syndrome independently increases the odds of habitual sleep curtailment in elderly individuals. Head injury may be a risk factor for future RLS; this requires further investigation as indirect evidence for a possible link between RLS and traumatic brain injury exists. © 2016 American Academy of Sleep Medicine.

  9. The phantom of the night: restless legs syndrome in amputees.

    PubMed

    Giummarra, Melita J; Bradshaw, John L

    2010-06-01

    Chronic pain conditions often "mimic" the symptoms of restless legs syndrome (RLS) with worse pain in the evening and upon rest, associated with an urge to move and relief upon movement. We propose that too little has been made of these parallels, with pain conditions resembling RLS being dismissed as mimics. We found, in a large questionnaire study (n=283) on phantom limb perception, a pattern of phantom pain that resembled RLS: amputees with nocturnal phantom pain were more likely to report worse pain upon rest and/or lying down, with an urge to move the phantom and/or walk to relieve their pain, and to experience spontaneous limb movements akin to periodic leg movements of RLS. We present the hypothesis that a model of restless legs syndrome may provide new insights into the mechanisms underlying phantom pain, and lead to new mechanism-based phantom pain treatment. In particular, central changes associated with sensory and motor symptoms of RLS, neuropathy, and dopamine may also be involved in those predisposed to experience phantom pain that mimics the symptoms of RLS. Ultimately, restless legs syndrome may indeed be a pain syndrome, and warrants further investigation in chronic pain populations.

  10. Thermally-assisted Magma Emplacement Explains Restless Calderas.

    PubMed

    Amoruso, Antonella; Crescentini, Luca; D'Antonio, Massimo; Acocella, Valerio

    2017-08-11

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei caldera, Italy. Campi Flegrei experienced at least 4 major unrest episodes in the last decades. Our results indicate that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust. Our thermal models show that this repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth ~3 ka before the last eruption. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks. Our model of thermally-assisted unrest may have a wider applicability, possibly explaining also the dynamics of other restless calderas.

  11. The Nova Outburst: Thermonuclear Runaways on Degenerated Dwarfs

    SciTech Connect

    Starrfield, S.; Truran, J.W.; Sparks, W.M.

    1999-07-08

    Observational and theoretical studies of the outbursts of classical novae have provided critical insights into a broad range of astrophysical phenomena. Thermonuclear runaways (TNRs) in accreted hydrogen-rich envelopes on the white dwarf (WD) components of close binary systems constitute not only the outburst mechanism for a classical nova explosion, but also the recurrent novae and a fraction of the symbiotic novae explosions. Studies of the general characteristics of these explosions, both in our own galaxy and in neighboring galaxies of varying metallicity, can teach us about binary stellar evolution, while studies of the evolution of nova binary systems can constrain models for the (as yet unidentified) progenitors of Type Ia supernovae. Further, the empirical relation between the peak luminosity of a nova and the rate of decline, which presents a challenge to theoretical models, allows novae to be utilized as standard candles for distance determinations out to the Virgo Cluster. E xtensive studies of novae with IUE and the resulting abundance determinations have revealed the existence of oxygen-neon white dwarfs in some systems. The high levels of enrichment of novae ejecta in elements ranging from carbon to sulfur confirm that there is significant dredge-up of matter from the core of the underlying white dwarf and enable novae to contribute to the chemical enrichment of the interstellar medium. Observations of the epoch of dust formation in the expanding shells of novae allow important constraints to be placed on the dust formation process and confirm that graphite, SiC, and SiO{sub 2} grains are formed by the outburst. It is possible that grains from novae were injected into the pre-solar nebula and can be identified with some of the pre-solar grains or ''stardust'' found in meteorites. Finally, g-ray observations during the first several years of their outburst, using the next generation of satellite observatories, could confirm

  12. A bioengineered niche preserves the quiescence of muscle stem cells and enhances their therapeutic efficacy

    PubMed Central

    Quarta, Marco; Brett, Jamie O.; DiMarco, Rebecca; De Morree, Antoine; Boutet, Stephane C.; Chacon, Robert; Gibbons, Michael C.; Garcia, Victor A.; Su, James; Shrager, Joseph B.; Heilshorn, Sarah; Rando, Thomas A.

    2016-01-01

    A promising therapeutic strategy for diverse genetic disorders involves transplantation of autologous stem cells that have been genetically corrected ex vivo. A major challenge in such approaches is a loss of stem cell potency during stem cell culture. Here we describe a system for maintaining muscle stem cells (MuSCs) in vitro in a potent, quiescent state. Using a machine learning method, we identified a molecular signature of quiescence and used it to screen for factors that could maintain mouse MuSC quiescence, thus defining a quiescence medium (QM). We also designed artificial muscle fibers (AMFs) that mimic the native myofiber of the MuSC niche. Mouse MuSCs maintained in QM on AMFs showed enhanced potential for engraftment, tissue regeneration and self-renewal after transplantation in mice. An artificial niche adapted to human MuSCs showed similarly prolonged quiescence in vitro and enhanced potency in vivo. Our approach for maintaining quiescence may be applicable to stem cells from a range of other tissues. PMID:27240197

  13. A gene-trap strategy identifies quiescence-induced genes in synchronized myoblasts.

    PubMed

    Sambasivan, Ramkumar; Pavlath, Grace K; Dhawan, Jyotsna

    2008-03-01

    Cellular quiescence is characterized not only by reduced mitotic and metabolic activity but also by altered gene expression. Growing evidence suggests that quiescence is not merely a basal state but is regulated by active mechanisms. To understand the molecular programme that governs reversible cell cycle exit, we focused on quiescence-related gene expression in a culture model of myogenic cell arrest and activation. Here we report the identification of quiescence-induced genes using a gene-trap strategy. Using a retroviral vector, we generated a library of gene traps in C2C12 myoblasts that were screened for arrest-induced insertions by live cell sorting (FACS-gal). Several independent gene- trap lines revealed arrest-dependent induction of betagal activity, confirming the efficacy of the FACS screen. The locus of integration was identified in 15 lines. In three lines,insertion occurred in genes previously implicated in the control of quiescence, i.e. EMSY - a BRCA2--interacting protein, p8/com1 - a p300HAT -- binding protein and MLL5 - a SET domain protein. Our results demonstrate that expression of chromatin modulatory genes is induced in G0, providing support to the notion that this reversibly arrested state is actively regulated.

  14. DYRK1A protein kinase promotes quiescence and senescence through DREAM complex assembly.

    PubMed

    Litovchick, Larisa; Florens, Laurence A; Swanson, Selene K; Washburn, Michael P; DeCaprio, James A

    2011-04-15

    In the absence of growth signals, cells exit the cell cycle and enter into G0 or quiescence. Alternatively, cells enter senescence in response to inappropriate growth signals such as oncogene expression. The molecular mechanisms required for cell cycle exit into quiescence or senescence are poorly understood. The DREAM (DP, RB [retinoblastoma], E2F, and MuvB) complex represses cell cycle-dependent genes during quiescence. DREAM contains p130, E2F4, DP1, and a stable core complex of five MuvB-like proteins: LIN9, LIN37, LIN52, LIN54, and RBBP4. In mammalian cells, the MuvB core dissociates from p130 upon entry into the cell cycle and binds to BMYB during S phase to activate the transcription of genes expressed late in the cell cycle. We used mass spectroscopic analysis to identify phosphorylation sites that regulate the switch of the MuvB core from BMYB to DREAM. Here we report that DYRK1A can specifically phosphorylate LIN52 on serine residue 28, and that this phosphorylation is required for DREAM assembly. Inhibiting DYRK1A activity or point mutation of LIN52 disrupts DREAM assembly and reduces the ability of cells to enter quiescence or undergo Ras-induced senescence. These data reveal an important role for DYRK1A in the regulation of DREAM activity and entry into quiescence.

  15. Theoretical determination of the strength characteristics of multilayer materials intended for nuclear and thermonuclear engineering

    NASA Astrophysics Data System (ADS)

    Vitkovskii, I. V.; Leshukov, A. Yu.; Romashin, S. N.; Shorkin, V. S.

    2015-12-01

    A method is developed to estimate the integrity of multilayer structures. This method is based on the version of the theory of adhesion and cohesion interactions of structure elements that only takes into account their thermomechanical properties. The structures to be studied are the material of the multilayer wall of the liquid-metal thermonuclear reactor blanket and a heat-resistant magnet wire with a bimetallic conductor, which is the base of the windings of the magnetohydrodynamic machines and electric motors intended for operation at high temperatures under ionizing radiation in, e.g., the machines and facilities in nuclear and thermonuclear reactors.

  16. A restless abdomen and propriospinal myoclonus like at sleep onset: an unusual overlap syndrome

    PubMed Central

    Baiardi, Simone; La Morgia, Chiara; Mondini, Susanna; Cirignotta, Fabio

    2015-01-01

    We report for the first time the association between restless abdomen, a phenotypic variant of restless legs syndrome in which symptoms are limited to the abdomen, and propriospinal myoclonus at sleep onset causing severe insomnia. The treatment with a low-dosage of dopaminergic drug (pramipexole) induced the immediate disappearance of both symptoms, which was documented by video-polysomnography. PMID:25820108

  17. Restless legs syndrome and its associated risk factors in Parkinson's disease.

    PubMed

    Azmin, Shahrul; Khairul Anuar, Abdul Manaf; Nafisah, Wan Yahya; Tan, Hui Jan; Raymond, Azman Ali; Hanita, Othman; Shah, Shamsul Azhar; Norlinah, Mohamed Ibrahim

    2013-01-01

    Introduction. Restless legs syndrome has been shown to negatively impact the quality of life of patients. Studies have shown an association between restless legs syndrome and Parkinson's disease. We attempted to investigate the prevalence of restless legs syndrome in Parkinson's disease patients and to identify associated risk factors. Method. This was a cross-sectional study among patients with idiopathic Parkinson's disease. Exclusion criterion was a Mini Mental State Examination score of less than 21/30. The International Restless Legs Syndrome Study Group criterion was used to identify patients with restless legs syndrome. Results. A total of 113 patients were recruited. The prevalence rate of restless legs syndrome in our cohort was 9.7% and was significantly associated with a younger onset of Parkinson's disease (P = 0.023), male gender (P = 0.045), higher Mini Mental State Examination score (P = 0.004), and less advanced Hoehn & Yahr stage (P = 0.014). Conclusion. The prevalence rate of restless legs syndrome in our Parkinson's disease population is in keeping with other studies published worldwide. The significance of the association between a younger onset of Parkinson's disease and restless legs syndrome needs to be further investigated.

  18. An array of nuclear microtubules reorganizes the budding yeast nucleus during quiescence

    PubMed Central

    Laporte, Damien; Courtout, Fabien; Salin, Bénédicte; Ceschin, Johanna

    2013-01-01

    The microtubule cytoskeleton is a highly dynamic network. In dividing cells, its complex architecture not only influences cell shape and movement but is also crucial for chromosome segregation. Curiously, nothing is known about the behavior of this cellular machinery in quiescent cells. Here we show that, upon quiescence entry, the Saccharomyces cerevisiae microtubule cytoskeleton is drastically remodeled. Indeed, while cytoplasmic microtubules vanish, the spindle pole body (SPB) assembles a long and stable monopolar array of nuclear microtubules that spans the entire nucleus. Consequently, the nucleolus is displaced. Kinetochores remain attached to microtubule tips but lose SPB clustering and distribute along the microtubule array, leading to a large reorganization of the nucleus. When cells exit quiescence, the nuclear microtubule array slowly depolymerizes and, by pulling attached centromeres back to the SPB, allows the recovery of a typical Rabl-like configuration. Finally, mutants that do not assemble a nuclear array of microtubules are impaired for both quiescence survival and exit. PMID:24247429

  19. The transcription factor MEF/ELF4 regulates the quiescence of primitive hematopoietic cells.

    PubMed

    Lacorazza, H Daniel; Yamada, Takeshi; Liu, Yan; Miyata, Yasuhiko; Sivina, Mariela; Nunes, Juliana; Nimer, Stephen D

    2006-03-01

    The transcriptional circuitry that regulates the quiescence of hematopoietic stem cells is largely unknown. We report that the transcription factor known as MEF (or ELF4), which is targeted by the t(X;21)(q26;q22) in acute myelogenous leukemia, regulates the proliferation of primitive hematopoietic progenitor cells at steady state, controlling their quiescence. Mef null HSCs display increased residence in G0 with reduced 5-bromodeoxyuridine incorporation in vivo and impaired cytokine-driven proliferation in vitro. Due to their increased HSC quiescence, Mef null mice are relatively resistant to the myelosuppressive effects of chemotherapy and radiation. Thus, MEF plays an important role in the decision of stem/primitive progenitor cells to divide or remain quiescent by regulating their entry to the cell cycle.

  20. Pten is necessary for the quiescence and maintenance of adult muscle stem cells

    PubMed Central

    Yue, Feng; Bi, Pengpeng; Wang, Chao; Shan, Tizhong; Nie, Yaohui; Ratliff, Timothy L.; Gavin, Timothy P.; Kuang, Shihuan

    2017-01-01

    Satellite cells (SCs) are myogenic stem cells required for regeneration of adult skeletal muscles. A proper balance among quiescence, activation and differentiation is essential for long-term maintenance of SCs and their regenerative function. Here we show a function of Pten (phosphatase and tensin homologue) in quiescent SCs. Deletion of Pten in quiescent SCs leads to their spontaneous activation and premature differentiation without proliferation, resulting in depletion of SC pool and regenerative failure. However, prior to depletion, Pten-null activated SCs can transiently proliferate upon injury and regenerate injured muscles, but continually decline during regeneration, suggesting an inability to return to quiescence. Mechanistically, Pten deletion increases Akt phosphorylation, which induces cytoplasmic translocation of FoxO1 and suppression of Notch signalling. Accordingly, constitutive activation of Notch1 prevents SC depletion despite Pten deletion. Our findings delineate a critical function of Pten in maintaining SC quiescence and reveal an interaction between Pten and Notch signalling. PMID:28094257

  1. Return to quiescence of murine neural stem cells by degradation of a pro-activation protein

    PubMed Central

    Urbán, Noelia; van den Berg, Debbie L.C.; Forget, Antoine; Andersen, Jimena; Demmers, Jeroen A.; Hunt, Charles; Ayrault, Olivier; Guillemot, François

    2017-01-01

    Quiescence is essential for long-term maintenance of adult stem cells. Niche signals regulate the transit of stem cells from dormant to activated states. Here we show that the E3-ubiquitin ligase Huwe1 (HECT, UBA and WWE domain containing 1) is required for proliferating stem cells of the adult mouse hippocampus to return to quiescence. Huwe1 destabilises pro-activation protein Ascl1 (achaete-scute family bHLH transcription factor 1) in proliferating hippocampal stem cells, which prevents accumulation of cyclin Ds and promotes the return to a resting state. When stem cells fail to return to quiescence, the proliferative stem cell pool becomes depleted. Thus, long-term maintenance of hippocampal neurogenesis depends on the return of stem cells to a transient quiescent state through the rapid degradation of a key activation factor. PMID:27418510

  2. Theoretical z -pinch scaling relations for thermonuclear-fusion experiments.

    PubMed

    Stygar, W A; Cuneo, M E; Vesey, R A; Ives, H C; Mazarakis, M G; Chandler, G A; Fehl, D L; Leeper, R J; Matzen, M K; McDaniel, D H; McGurn, J S; McKenney, J L; Muron, D J; Olson, C L; Porter, J L; Ramirez, J J; Seamen, J F; Speas, C S; Spielman, R B; Struve, K W; Torres, J A; Waisman, E M; Wagoner, T C; Gilliland, T L

    2005-08-01

    implosion time tau(i). For an accelerator coupled to a double-pinch-driven hohlraum that drives the implosion of an ICF fuel capsule, we find that the accelerator power and energy required to achieve high-yield fusion scale as tau(i)0.36 and tau(i)1.36, respectively. Thus the accelerator requirements decrease as the implosion time is decreased. However, the x-ray-power and thermonuclear-yield efficiencies of such a coupled system increase with tau(i). We also find that increasing the anode-cathode gap of the pinch from 2 to 4 mm increases the requisite values of P(a) and E(a) by as much as a factor of 2.

  3. Curious Variables Experiment (CURVE) CCD photometry of QW Serpentis in superoutburst and quiescence

    NASA Astrophysics Data System (ADS)

    Olech, A.; Kȩdzierski, P.; Złoczewski, K.; Mularczyk, K.; Wiśniewski, M.

    2003-12-01

    We report extensive photometry of the dwarf nova QW Ser throughout its February 2003 superoutburst untill quiescence. During the superoutburst the star displayed clear superhumps with a mean period of P_sh = 0.07703(4) days. In the quiescence we observed a double humped wave characterized by a period of P=0.07457(2) days. As both periods obey the Stolz-Schoembs relation with a period excess equal to 3.30+/-0.06%, the latter period is interpreted as the orbital period of the binary system

  4. [Signaling molecules and pathways involved in maintaining the quiescence of primordial follicles].

    PubMed

    Hu, Liao-Liao; Xiang, Cheng; Zheng, Li-Ping

    2015-02-25

    Reproductive lifespan in female mammals is related to the size of primordial follicles pool, which relies on the balance between activated and quiescent primordial follicles. Therefore, the molecular mechanisms of recruiting and maintaining quiescence of primordial follicles have become hot research topics recently. Multiple studies have shown that genetic mutations, local ovarian autocrine and paracrine factors, proto-oncogene and tumor-suppressor genes are involved in the maintenance of balance between quiescent and activated primordial follicles. In the present review, we summarize recent research progress of the important signaling molecules and pathways that maintain the quiescence of primordial follicles.

  5. Probing thermonuclear flame spreading on neutron stars using burst rise oscillations

    NASA Astrophysics Data System (ADS)

    Chakraborty, Manoneeta; Bhattacharyya, Sudip

    2016-07-01

    Intense X-ray bursts (type-I bursts), originated from runaway thermonuclear processes, are observed from the surfaces of many accreting neutron star Low Mass X-ray Binary (LMXB) systems and they provide an important tool to constrain the neutron star equation of state. Periodic intensity variations during these bursts, termed burst oscillations, are observed in about 10% of thermonuclear bursts. Oscillations during the rising phases of thermonuclear bursts are hypothesized to originate from an expanding hot-spot on the surface of the neutron star. We studied the evolution of oscillations during the rising phase of a large sample of thermonuclear bursts from 10 bursting neutron stars in order to probe the process of burning front propagation during an X-ray burst. Our results show observational evidences of expanding hot-spot with spin modulated flame speeds, possibly due to the effects of the Coriolis force present as a result of the high stellar spin (270-620 Hz). This implies that the flame propagation is latitude-dependent and we address the factors affecting the detection and non-detection of burst rise oscillations in the light of this Coriolis force modulated flame spreading scenario.

  6. Diagnosis and management of restless legs syndrome in children

    PubMed Central

    Simakajornboon, Narong; Kheirandish-Gozal, Leila; Gozal, David

    2010-01-01

    Summary Recent published evidence suggests that restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are common condition in children and adolescents. It is likely that if left untreated, RLS and PLMD may lead to adverse cardiovascular and neurocognitive consequences. However, the diagnosis of RLS and PLMD in children is challenging, particularly because children are relatively unable to describe typical RLS symptoms. The International Restless Legs Study Group has recently published consensus criteria for the diagnosis of RLS and PLMD in children. In addition to clinical description of RLS symptoms, supportive evidence including the presence of clinical sleep disturbances, documented periodic limb movements in sleep from overnight sleep study and family history of restless legs syndrome may be required. Few if any controlled studies have addressed the management of RLS and PLMD, which may involve both non-pharmacologic and pharmacologic approaches. In this context, the importance of avoidance of aggravating factors and good sleep hygiene cannot be overemphasized. Children with evidence of low-iron storage, i.e., low-serum ferritin and/ or iron levels may likely benefit from iron therapy. While there is overall limited experience regarding the use of dopaminergic agents in children with RLS and PLMD, published reports suggesting efficacy of compounds such as levodopa, ropinirole, pramipexole and pergolide have emerged. Other medications including benzodiazepine, anti-convulsants, alpha-adrenergic and opioid medications have not been adequately studied in children. Children with RLS and PLMD should have regular follow-up visits to evaluate clinical improvement and to monitor adverse effects from the selected therapy. Based on aforementioned findings, it is clear that a substantial research effort is needed to evaluate the pathophysiology, PMID:19186083

  7. Restless Legs Syndrome and Sleep-Wake Disturbances in Pregnancy

    PubMed Central

    Dunietz, Galit Levi; Lisabeth, Lynda D.; Shedden, Kerby; Shamim-Uzzaman, Q. Afifa; Bullough, Alexandra S.; Chames, Mark C.; Bowden, Marc F.; O'Brien, Louise M.

    2017-01-01

    Study Objectives: To estimate the association of restless legs syndrome (RLS) and its frequency with sleep-wake disturbances in pregnancy. Methods: A cohort of 1,563 women in their third trimester of pregnancy were recruited from prenatal clinics between March 2007 and December 2010. Demographic, pregnancy, and delivery data were extracted from medical records and sleep information was collected with questionnaires. To diagnose RLS, we used standardized criteria of RLS symptoms and frequency that were developed by the International Restless Legs Study Group. Logistic regression models were constructed to investigate the association of RLS and its frequency with sleep-wake disturbances (poor sleep quality, daytime sleepiness, poor daytime function) and delivery outcomes. Results: Overall 36% of the pregnant women had RLS, and half had moderate to severe symptoms. Compared to women without RLS, those with RLS were more likely to have poor sleep quality (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.7–2.9), poor daytime function (OR 1.9, 95% CI 1.4–2.4), and excessive daytime sleepiness (OR 1.6, 95% CI 1.3–2.0). A dose-response relationship also was evident between RLS frequency and each of the sleep-wake disturbances. There was no evidence for any association between RLS and delivery outcomes. Conclusions: RLS is a significant contributor to poor sleep quality, daytime sleepiness, and poor daytime function, all common and often debilitating conditions in pregnancy. Obstetric health care providers should be aware of these associations and screen women for RLS. Commentary: A commentary on this article appears in this issue on page 857. Citation: Dunietz GL, Lisabeth LD, Shedden K, Shamim-Uzzaman A, Bullough AS, Chames MC, Bowden MF, O'Brien LM. Restless legs syndrome and sleep-wake disturbances in pregnancy. J Clin Sleep Med. 2017;13(7):863–870. PMID:28633715

  8. Diagnosis of Restless Leg Syndrome (Willis-Ekbom Disease).

    PubMed

    Becker, Philip M

    2015-09-01

    Restless leg syndrome, or Willis-Ekbom disease, is a neurosensorimotor disorder with significant impact that is diagnosed through 5 clinical criteria. Adherence to 5 criteria and a thorough physical examination are often sufficient for diagnosis. Associated features prove helpful in young children or the cognitively impaired. Polysomnography is not routinely required unless the patient has other sleep-related symptoms. The finding of periodic leg movements in sleep only suggests, instead of confirms, the diagnosis. It is important to arrive at appropriate diagnosis because the prevalence is in the millions and treatment significantly improves sleep quality and daytime function. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Restless legs syndrome: diagnostic time-savers, Tx tips.

    PubMed

    Moyer, Darlene E; Zayas-Bazan, Javier; Reese, Gary

    2009-08-01

    To diagnose restless legs syndrome (RLS), start with the 4 "essential criteria": (1) a powerful urge to move the legs that is (2) rest-induced, (3) improves with activity, and (4) worsens in the evening. Carefully screen for secondary causes of RLS, including renal failure, pregnancy, iron deficiency, and medications that can cause or exacerbate symptoms. Carbidopa/levodopa is the first-line treatment for patients with intermittent symptoms of RLS; dopamine agonists are recommended for those with daily or refractory symptoms.

  10. The Restless Sea: Exploring the World Beneath the Waves

    NASA Astrophysics Data System (ADS)

    Knauss, John A.

    I have often been disappointed by popular science books. In the attempt to reach a large audience the author too often loses the subtlety and the excitement that accompanies scientific discovery. Even knowing the author was the 1994 recipient of AGU's Walter Sullivan Award, given for excellence in science journalism, I approached The Restless Sea: Exploring the World Beneath the Waves with little anticipation.But by the third chapter I was hooked. By the last chapter I was prepared to recommend it, and recommend it strongly not only to the nonocean members of AGU, but to all of my fellow members of the Ocean Science section as well.

  11. Restless legs syndrome and periodic leg movements of sleep.

    PubMed

    Rye, David B; Trotti, Lynn Marie

    2012-11-01

    Women are more commonly affected than men by restless legs syndrome, and prevalence is highest amongst those of northern European heritage. The motor manifestations include nonvolitional myoclonus (periodic leg movements). Disinhibition of spinal sensorimotor circuits may underlie these primary features and can be affected by peripheral as well as supraspinal networks. Insufficient mobilizable iron stores increase expressivity in some individuals. The sensorimotor features are relieved by dopamine, especially dopamine agonists, gabapentin and its derivatives, and opioids. A diagnosis relies on recognition of key primary and supportive features, and treatments are generally well tolerated, efficacious, and life-changing. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Dementia-related restlessness: relationship to characteristics of persons with dementia and family caregivers.

    PubMed

    Regier, Natalie G; Gitlin, Laura N

    2017-03-23

    Dementia-related restlessness is commonly endorsed by caregivers but not well understood. This study examines differences in characteristics (demographics, cognitive status, physical function, pain, and mood) of persons with dementia whose caregivers endorse restlessness versus those who do not. We also examine the relationship of restlessness to caregiver well-being including burden, upset with behaviors, mastery, and depressive symptomatology. We combined baseline data from three caregiver intervention studies of community-dwelling persons with dementia who exhibited neuropsychiatric symptoms (n = 569) as measured by the Agitated Behaviors in Dementia Scale. We conducted bivariate correlations and independent t-tests by using the Agitated Behaviors in Dementia Scale restlessness item. Nearly 65% (n = 367) of dementia caregivers reported restlessness. There were no significant differences between those with and without (n = 202) reported restlessness concerning functional status (physical or cognitive). However, persons with restlessness had significantly higher pain scores (p < 0.01), were more likely to be on behavioral medications (p < 0.001), and had more neuropsychiatric symptoms as compared with persons without restlessness (M = 11.11, nonrestless; M = 6.61, restless) (p < 0.001). Caregivers of persons with dementia-related restlessness reported greater burden (p < 0.001), behavioral upset (p < 0.001), depression (p < 0.001), and lower mastery providing care (p < 0.01) compared with caregivers of persons without dementia-related restlessness. Restlessness is a common neuropsychiatric symptom that appears to be associated with poorer functioning in persons with dementia and greater distress in their caregivers. Further research is needed to understand the unique contributions of restlessness to care burden and quality of life of persons with dementia, as well as ways to address this distressing symptom. Copyright © 2017 John Wiley

  13. Restless legs syndrome: prevalence and impact in children and adolescents--the Peds REST study.

    PubMed

    Picchietti, Daniel; Allen, Richard P; Walters, Arthur S; Davidson, Julie E; Myers, Andrew; Ferini-Strambi, Luigi

    2007-08-01

    Restless legs syndrome, a common neurologic sleep disorder, occurs in 5% to 10% of adults in the United States and Western Europe. Although approximately 25% of adults with restless legs syndrome report onset of symptoms between the ages of 10 and 20 years, there is very little literature looking directly at the prevalence in children and adolescents. In this first population-based study to use specific pediatric diagnostic criteria, we examined the prevalence and impact of restless legs syndrome in 2 age groups: 8 to 11 and 12 to 17 years. Initially blinded to survey topic, families were recruited from a large, volunteer research panel in the United Kingdom and United States. Administration was via the Internet, and results were stratified by age and gender. National Institutes of Health pediatric restless legs syndrome diagnostic criteria (2003) were used, and questions were specifically constructed to exclude positional discomfort, leg cramps, arthralgias, and sore muscles being counted as restless legs syndrome. Data were collected from 10,523 families. Criteria for definite restless legs syndrome were met by 1.9% of 8- to 11-year-olds and 2.0% of 12- to 17-year-olds. Moderately or severely distressing restless legs syndrome symptoms were reported to occur > or = 2 times per week in 0.5% and 1.0% of children, respectively. Convincing descriptions of restless legs syndrome symptoms were provided. No significant gender differences were found. At least 1 biological parent reported having restless legs syndrome symptoms in > 70% of the families, with both parents affected in 16% of the families. Sleep disturbance was significantly more common in children and adolescents with restless legs syndrome than in controls (69.4% vs 39.6%), as was a history of "growing pains" (80.6% vs 63.2%). Various consequences were attributed to restless legs syndrome, including 49.5% endorsing a "negative effect on mood." Data were also collected on comorbid conditions and restless

  14. [Human life and energy production. Prospects opened up by controlled thermonuclear fusion].

    PubMed

    Escande, D

    1997-03-18

    The massive and presently increasing energy production is going to confront mankind with a very important problem in the forthcoming decades, in particular due to the vanishing of resources and to the greenhouse effect. The share of fossil fuels in the energy production will have to decrease, and other energy sources will be needed. Among them controlled thermonuclear fusion has may assets due to its non-radioactive fuel with plentiful supply, its non radioactive and non polluting ashes, its safety, its weak environmental impact, and its irrelevance to nuclear proliferation in a normal setting. During the last three decades, physicists have made a series of steps toward the peaceful use of the dominant source of energy in the Universe. They have learned how to confine by magnetic fields plasmas at temperatures of 200 millions degrees centigrade, and they have developed several specific technologies. This way, they produced 11 million watts of nuclear power by fusing two isotopes of hydrogen. These investigations are conducted in a responsible spirit, that of ecoproduction, where possible negative consequences are anticipated, are made as low as reasonably achievable, and their management is studied. Yet several fundamental issues still have to be solved before on economically efficient industrial thermonuclear power plant be operated. A huge international collaboration involving Japan, the USA, the Russian Federation, and the European Union joined with Switzerland and Canada, is presently designing the first experimental thermonuclear reactor, the International Thermonuclear Experimental Reactor (ITER). It would cost 9 billion dollars, a cost similar to other large scientific projects. This is an important step toward an electricity producing thermonuclear reactor that would be both safe and respectful of human health and of environment.

  15. Pericytes in the myovascular niche promote post-natal myofiber growth and satellite cell quiescence.

    PubMed

    Kostallari, Enis; Baba-Amer, Yasmine; Alonso-Martin, Sonia; Ngoh, Pamela; Relaix, Frederic; Lafuste, Peggy; Gherardi, Romain K

    2015-04-01

    The satellite cells, which serve as adult muscle stem cells, are both located beneath myofiber basement membranes and closely associated with capillary endothelial cells. We observed that 90% of capillaries were associated with pericytes in adult mouse and human muscle. During post-natal growth, newly formed vessels with their neuroglial 2 proteoglycan (NG2)-positive pericytes became progressively associated with the post-natal muscle stem cells, as myofibers increased in size and satellite cells entered into quiescence. In vitro, human muscle-derived pericytes promoted myogenic cell differentiation through insulin-like growth factor 1 (IGF1) and myogenic cell quiescence through angiopoietin 1 (ANGPT1). Diphtheria toxin-induced ablation of muscle pericytes in growing mice led both to myofiber hypotrophy and to impaired establishment of stem cells quiescence. Similar effects were observed following conditional in vivo deletion of pericyte Igf1 and Angpt1 genes, respectively. Our data therefore demonstrate that, by promoting post-natal myogenesis and stem cell quiescence, pericytes play a key role in the microvascular niche of satellite cells. © 2015. Published by The Company of Biologists Ltd.

  16. CDK6 Levels Regulate Quiescence Exit in Human Hematopoietic Stem Cells

    PubMed Central

    Laurenti, Elisa; Frelin, Catherine; Xie, Stephanie; Ferrari, Robin; Dunant, Cyrille F.; Zandi, Sasan; Neumann, Andrea; Plumb, Ian; Doulatov, Sergei; Chen, Jing; April, Craig; Fan, Jian-Bing; Iscove, Norman; Dick, John E.

    2015-01-01

    Summary Regulated blood production is achieved through the hierarchical organization of dormant hematopoietic stem cell (HSC) subsets that differ in self-renewal potential and division frequency, with long-term (LT)-HSCs dividing the least. The molecular mechanisms underlying this variability in HSC division kinetics are unknown. We report here that quiescence exit kinetics are differentially regulated within human HSC subsets through the expression level of CDK6. LT-HSCs lack CDK6 protein. Short-term (ST)-HSCs are also quiescent but contain high CDK6 protein levels that permit rapid cell cycle entry upon mitogenic stimulation. Enforced CDK6 expression in LT-HSCs shortens quiescence exit and confers competitive advantage without impacting function. Computational modeling suggests that this independent control of quiescence exit kinetics inherently limits LT-HSC divisions and preserves the HSC pool to ensure lifelong hematopoiesis. Thus, differential expression of CDK6 underlies heterogeneity in stem cell quiescence states that functionally regulates this highly regenerative system. PMID:25704240

  17. Computational identification of a p38SAPK regulated transcription factor network required for tumor cell quiescence

    PubMed Central

    Adam, Alejandro P.; George, Ajish; Schewe, Denis; Bragado, Paloma; Iglesias, Bibiana V.; Ranganathan, Aparna C.; Kourtidis, Antonis; Conklin, Douglas S.; Aguirre-Ghiso, Julio A.

    2009-01-01

    The stress activated kinase p38 plays key roles in tumor suppression and induction of tumor cell dormancy. However, the mechanisms behind these functions remain poorly understood. Using computational tools we identified a transcription factor (TF) network regulated by p38α/β and required for human squamous carcinoma cell quiescence in vivo. We found that p38 transcriptionally regulates a core network of 46 genes that includes 16 TFs. Activation of p38 induced the expression of the TFs p53 and BHLHB3, while inhibiting c-Jun and FoxM1 expression. Further, induction of p53 by p38 was dependent on c-Jun downregulation. Accordingly, while RNAi downregulation of BHLHB3 or p53 interrupted tumor cell quiescence; downregulation of c-Jun or FoxM1 or overexpression of BHLHB3 in malignant cells mimicked the onset of quiescence. Our results identify components of the regulatory mechanisms driving p38-induced cancer cell quiescence. These may regulate dormancy of residual disease that usually precedes the onset of metastasis in many cancers. PMID:19584293

  18. Multiwavelength observations of the gamma-ray blazar PKS 0528+134 in quiescence

    DOE PAGES

    Palma, N. I.; Böttcher, M.; de la Calle, I.; ...

    2011-06-16

    Here, we present multiwavelength observations of the ultraluminous blazar-type radio loud quasar PKS 0528+134 in quiescence during the period July to December 2009. Four Target-of-Opportunity (ToO) observations with the XMM-Newton Satellite in the 0.2 – 10 keV range were supplemented with optical observations.

  19. Multiwavelength observations of the gamma-ray blazar PKS 0528+134 in quiescence

    SciTech Connect

    Palma, N. I.; Böttcher, M.; de la Calle, I.; Agudo, I.; Aller, M.; Aller, H.; Bach, U.; Benítez, E.; Buemi, C. S.; Escande, L.; Gómez, J. L.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Jorstad, S. G.; Joshi, M.; Lähteenmäki, A.; Larionov, V. M.; Leto, P.; Li, Y.; López, J. M.; Lott, B.; Madejski, G.; Marscher, A. P.; Morozova, D. A.; Raiteri, C. M.; Roberts, V.; Tornikoski, M.; Trigilio, C.; Umana, G.; Villata, M.; Wylezalek, D.

    2011-06-16

    Here, we present multiwavelength observations of the ultraluminous blazar-type radio loud quasar PKS 0528+134 in quiescence during the period July to December 2009. Four Target-of-Opportunity (ToO) observations with the XMM-Newton Satellite in the 0.2 – 10 keV range were supplemented with optical observations.

  20. Isoform α of PKC may contribute to the maintenance of pregnancy myometrial quiescence in humans.

    PubMed

    Jofré, Nicolás M; Delpiano, Ana M; Cuello, Mauricio A; Poblete, José A; Vargas, Paula A; Carvajal, Jorge A

    2013-01-01

    We postulate that protein kinase C α (PKCα) may contribute to the maintenance of pregnancy myometrial quiescence in humans. We studied the changes in myometrial PKCα gene products (messenger RNA [mRNA] and protein) in 4 groups of women: preterm not in labor (PT-NL), preterm in labor (PT-L), term not in labor (T-NL), and term in labor (T-L). The degree of PKCα activation was studied by comparing the levels of particulate (active) PKCα with the total PKCα protein levels and by measuring PKCα activity in the cytosolic and particulate fractions. Protein kinase Cα abundance (mRNA and protein) did not increase during myometrial quiescence (PT-NL), whereas the level of PKCα activity significantly increased during quiescence. The activity of PKCα significantly decreased in the T-NL, T-L, and PT-L groups. These findings suggest that PKCα plays a significant role in the maintenance of myometrial quiescence and that PKCα activity must decrease at the end of pregnancy allowing myometrial activation. Additionally, our data demonstrate an association between reduced PKCα activity and preterm labor, which merits further investigation.

  1. A new role for an old friend: NFAT and stem cell quiescence.

    PubMed

    Oro, Anthony E

    2008-02-07

    NFAT proteins are calcium-regulated transcription factors that play a critical role during the timing and activation of many vertebrate tissues. A recent paper in Cell (Horsley et al., 2008) demonstrates a role of the calcineurin-NFAT-CDK4 pathway in maintaining hair follicle stem cell quiescence.

  2. Pancreatic small cells: Analysis of quiescence, long-term maintenance and insulin expression in vitro

    SciTech Connect

    Petropavlovskaia, M. . E-mail: maria.petropavlovskaia@mail.mcgill.ca; Bodnar, C.A.; Behie, L.A.; Rosenberg, L.

    2007-03-10

    We have previously identified a novel population of small cells in human and canine pancreas characterized by immature morphology, quiescence, and a glucose-responsive insulin secretion. Based on their immature phenotype and predominant presence in small islets, we have hypothesized that small cells serve as islet progenitors. This hypothesis remains untested, however, due to persistent quiescence and scarcity of small cells in vitro. We have recently developed a culture medium that allowed for modest small cell proliferation. In this study we characterized the expression of genes potentially involved in small cell growth regulation by Q-RT-PCR. Our results suggest that quiescence of small cells correlates with up-regulation of Cdk inhibitors p27{sup Kip1}, p16{sup INK4a} and p21{sup CIP1}, PTEN, Hep27 and Foxo1a and with down-regulation of c-Myc and the receptors for EGF, FGF2 and HGF. The exit from quiescence correlates with activation of EGFR expression and down-regulation of p27{sup Kip1} and p16{sup INK4a}. We also report here that small cells can be maintained in long-term non-adherent cultures preserving insulin and glucagon production for up to 208 days. Therefore, expansion of small cells in vitro may have a significant potential for the treatment of diabetes. This study is an important step in understanding the mechanisms involved in small cell growth regulation, which is required to fully evaluate their functional potential.

  3. The Saccharomyces cerevisiae protein Stm1p facilitates ribosome preservation during quiescence

    SciTech Connect

    Van Dyke, Natalya; Chanchorn, Ekkawit; Van Dyke, Michael W.

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer Stm1p confers increased resistance to the macrolide starvation-mimic rapamycin. Black-Right-Pointing-Pointer Stm1p maintains 80S ribosome integrity during stationary phase-induced quiescence. Black-Right-Pointing-Pointer Stm1p facilitates polysome formation following quiescence exit. Black-Right-Pointing-Pointer Stm1p facilitates protein synthesis following quiescence exit. Black-Right-Pointing-Pointer Stm1p is a ribosome preservation factor under conditions of nutrient deprivation. -- Abstract: Once cells exhaust nutrients from their environment, they enter an alternative resting state known as quiescence, whereby proliferation ceases and essential nutrients are obtained through internal stores and through the catabolism of existing macromolecules and organelles. One example of this is ribophagy, the degradation of ribosomes through the process of autophagy. However, some ribosomes need to be preserved for an anticipated recovery from nutrient deprivation. We found that the ribosome-associated protein Stm1p greatly increases the quantity of 80S ribosomes present in quiescent yeast cells and that these ribosomes facilitate increased protein synthesis rates once nutrients are restored. These findings suggest that Stm1p can act as a ribosome preservation factor under conditions of nutrient deprivation and restoration.

  4. Do we understand children's restlessness? Constructing ecologically valid understandings through reflexive cooperation

    PubMed Central

    Binder, Per-Einar; Stige, Brynjulf

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is the most widely used children's mental health diagnosis today, but the validity of the diagnosis is controversial, for instance, because it might conceal relational and ecological dimensions of restlessness. We invited parents and professionals from one local community in western Norway to participate in cooperative group discussions on how to conceptualize and understand children's restlessness. We carried out a thematic and reflexive analysis of the cooperative group discussions on ADHD and children's restlessness, and present findings related to three ecological levels inspired by Bronfenbrenner's ecological systems model. At the level of the individual, restlessness was discussed as individual trait, as the expectation to be seen and heard, and as a result of traumatization. At the level of dyad, group or family, restlessness was discussed as a relational phenomenon and as parents' problems. At the level of community, restlessness was discussed as lack of cooperation and lack of structures or resources. Our findings show how contextualized and cooperative reflexivity can contribute to more valid understandings of children's restlessness, and how cooperative inquiry can stimulate reflections about solidarity and sustainability in relation to adult's actions. PMID:26701898

  5. Persistent genital arousal and restless genitalia: sexual dysfunction or subtype of vulvodynia?

    PubMed

    Markos, A R; Dinsmore, Wallace

    2013-11-01

    We conducted a literature review of patients' conditions described under persistent genital arousal disorder and restless genital syndrome, vulvodynia and male genital skin pain of unknown aetiology (penoscrotodynia). Our aim is to improve the understanding of the condition, unify nomenclature and promote evidence-based practice. The most prominent symptom in persistent genital arousal disorder and restless genital syndrome is a spontaneous, unwelcomed, intrusive and distressing vulval sensation. There are similarities between the clinical presentation of vulvodynia, penoscrotodynia, persistent genital arousal disorder and restless genital syndrome patients. The aetiology of persistent genital arousal disorder and restless genital syndrome, similar to vulvodynia, could be better explained in terms of neuro-vascular dysfunction, genital peripheral neuropathy and/or dysfunctional micro-vascular arterio-venous shunting. Erythromelalgia lends itself to explain some cases of restless genital syndrome, who have concurrent restless legs syndrome; and therefore draw parallels with the red scrotum syndrome. The published literature supports the concept of classifying restless genital syndrome as a sub-type of vulvodynia rather than sexual dysfunction.

  6. The influence of antidepressants on restless legs syndrome and periodic limb movements: A systematic review.

    PubMed

    Kolla, Bhanu Prakash; Mansukhani, Meghna P; Bostwick, J Michael

    2017-06-15

    Restless legs syndrome is commonly co-morbid with medical conditions that are treated with antidepressant medications, such as depression, anxiety, fibromyalgia, and chronic insomnia disorder. Evidence from case reports and cross-sectional studies suggests that antidepressants may induce or worsen restless legs syndrome and increase periodic limb movements. We undertook a systematic review of the literature to identify and collate all prospective studies that measured restless legs syndrome symptoms and/or periodic limb movements following the introduction of an antidepressant. Eighteen studies were eligible for inclusion. Current data indicate that onset or exacerbation of restless legs syndrome and rise in frequency of periodic limb movements are uncommon following the initiation of an antidepressant. Among the various antidepressants, mirtazapine may be associated with higher rates of restless legs syndrome and periodic limb movements. One small study of normal volunteers suggested that venlafaxine may be associated with an increase in restless legs syndrome symptoms and periodic limb movements. Sertraline, fluoxetine, and amitriptyline appear to increase periodic limb movements that do not disrupt sleep and are thus unlikely to be clinically significant. On the other hand, bupropion may reduce restless legs syndrome symptoms, at least in the short term. Sedating antidepressants such as trazodone, nefazodone, and doxepin do not seem to aggravate periodic limb movements. The current evidence is limited by poor study design, inadequate use of standardized questionnaires, and heterogeneous populations studied for variable lengths of time. Future research should attempt to remedy these shortcomings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The effect of selenium administration on restless leg syndrome treatment.

    PubMed

    Rahimdel, A G; Ayatollahi, P; Zeinali, A; Mehrabanian, N; Mellat-Ardekani, A

    2012-01-01

    Restless leg syndrome (RLS) is defined as an uncomfortable feeling in the limbs which is prominently sensed in legs. Dopamine system involvement is considered as the base of RLS's etiology. Because of safety, anti-oxidant and dopaminergic promoting action of selenium, this study aims to investigate the effect of selenium on restless leg syndrome treatment. Sixty patients with primary RLS were enrolled in this clinical trial (Irct2011103015943n1). It was based on 3 periods of drug prescription with one month wash out period. As placebo, 50 and 200 μg of selenium were administered in each separated month. The diagnosis was based on criteria published by IRLSG (International RLS Study Group). The questionnaire included 10 questions while each question's rating was between 0 and 4. Points between 1 and 10 were considered mild, 11 to 20 as moderate, 21 to 30 as severe and 31 to 40 as very severe. After end of each month of drug consumption, questionnaires were completed and each subject was asked to report the severity of disease and side effects of the drugs. At least 10 declines in scale were considered as appropriate responses. Improvement (decline IRLS score >10) was significantly higher in selenium (50 and 200 μg) than placebo group. Selenium prescription in daily recommended dose of 50 μg instead of a dopamine agonist would be an alternative treatment in improvement of RLS symptoms.

  8. Is There an Association between Restless Legs Syndrome and Urticaria?

    PubMed

    Tuna, Serpil; Alan, Sevil; Samancı, Nehir; Karakaş, Ayşe Akman

    2016-05-01

    Restless legs syndrome (RLS) is a disease characterized by the urge to move the legs and sleep disturbances. Similarly, chronic spontaneous urticaria (CSU) is a dermatological disease characterized by pruritus and sleep disorders. In this study, we aimed to determine the prevalence and severity of RLS in patients with chronic spontaneous urticaria (CSU) and to compare the quality of sleep of patients with and without RLS in the CSU group using the Pittsburgh Sleep Quality Index. A total of 130 patients with CSU and 100 healthy controls were included in this study. The frequency of RLS, frequency of sleep disturbances, and average score of RLS in patients with CSU were statistically significantly higher than control groups (respectively P = 0.008, P = 0.009, P = 0.004). Subjective sleep quality, sleep latency and habitual sleep efficiency scores in patients with RLS were statistically significantly higher than patients without RLS (respectively P = 0.016, P = 0.007, P = 0.035). We claimed that pruritus of urticaria may decrease the quality of sleep in patients with RLS and it may trigger and worsen the restless legs syndrome. Furthermore, RLS and CSU may share a common etiology.

  9. Pregabalin for the Treatment of Restless Legs Syndrome.

    PubMed

    Griffin, Emily; Brown, Jamie N

    2016-07-01

    To evaluate the efficacy and safety of pregabalin for the treatment of restless legs syndrome (RLS). A search of the MEDLINE database (1956-February 2016) and EMBASE (1957-February 2016) was conducted, using the terms pregabalin and restless legs syndrome In addition, a manual review of the references cited in each publication identified from the database search was conducted to identify relevant articles. All English-language, peer-reviewed publications were evaluated for relevance. From an initial review of 285 articles, 5 clinical trials were included in the final analysis. Pregabalin is an analog of γ-aminobutyric acid that exhibits antinociceptive and anticonvulsant activity by binding to voltage-gated calcium channels in the central nervous system. Studies of pregabalin have demonstrated efficacy through significant reductions in mean International RLS Scale scores and wake after sleep onset scores, and it had a lower rate of augmentation than pramipexole treatment. Study durations ranged from 6 to 52 weeks, with doses ranging from 150 to 600 mg daily. The most common adverse effects associated with pregabalin use in all studies included dizziness and somnolence. Clinical evidence suggests that pregabalin may improve symptoms of RLS and reduce disturbances in sleep, resulting in improvements in quality of life for patients affected by the disease. Pregabalin is considered to be relatively safe and poses a minimal risk of augmentation unlike current recommended first-line treatments for RLS. Thus, evidence suggests that pregabalin is a reasonable therapeutic option for the treatment of RLS. © The Author(s) 2016.

  10. Restless legs syndrome/Willis Ekbom disease: evaluation and treatment.

    PubMed

    Allen, Richard P

    2014-04-01

    Restless legs syndrome/Willis Ekbom disease (RLS/WED) has been recognized as a significant medical disorder since the 17th century. It was studied mostly in the last 50 years in relation to increasing interest in sleep medicine and health-related quality of life. This led to recognition that the disease is not well characterized as restless feelings in the legs. These symptoms are reported in many situations, but the subjective experience of RLS/WED patients differs from that experienced by others. Thus a new name has been introduced that avoids problems of symptom definition of a disease by naming it after those who first characterized it, i.e. 'Willis Ekbom disease'. This article emphasizes the importance of RLS/WED for psychiatry. The disease carries significant increased risk for depression and anxiety disorders. Treatment requires consideration of these co-morbid disorders. RLS/WED can exacerbate or even engender psychiatric disease, so treatment of psychiatric disease should also include consideration of RLS/WED. The need for attention to RLS/WED is particularly significant for depression. Most anti-depressants exacerbate or can even engender RLS/WED. Thus this article seeks to introduce RLS/WED in relation to psychiatric practice. It presents the RLS/WED disease, its overlap with psychiatry and the current treatment options.

  11. Diagnosis, comorbidities, and management of restless legs syndrome.

    PubMed

    Becker, Philip M; Novak, Marta

    2014-08-01

    This narrative review describes the differential diagnosis of restless legs syndrome, and provides an overview of the evidence for the associations between RLS and potential comorbidities. Secondary causes of RLS and the characteristics of pediatric RLS are also discussed. Finally, management strategies for RLS are summarized. The review began with a comprehensive PubMed search for 'restless legs syndrome/Willis-Ekbom disease' in combination with the following: anxiety, arthritis, attention-deficit hyperactivity disorder, cardiac, cardiovascular disease, comorbidities, depression, end-stage renal disease, erectile dysfunction, fibromyalgia, insomnia, kidney disease, liver disease, migraine, mood disorder, multiple sclerosis, narcolepsy, neuropathy, obesity, pain, Parkinson's disease, polyneuropathy, pregnancy, psychiatric disorder, sleep disorder, somatoform pain disorder, and uremia. Additional papers were identified by reviewing the reference lists of retrieved publications. Although clinical diagnosis of RLS can be straightforward, diagnostic challenges may arise when patients present with comorbid conditions. Comorbidities of RLS include insomnia, depressive and anxiety disorders, and pain disorders. Differential diagnosis is particularly important, as some of the medications used to treat insomnia and depression may exacerbate RLS symptoms. Appropriate diagnosis and management of RLS symptoms may benefit patient well-being and, in some cases, may lessen comorbid disease burden. Therefore, it is important that physicians are aware of the presence of RLS when treating patients with conditions that commonly co-occur with the disorder.

  12. Actigraph Evaluation of Acupuncture for Treating Restless Legs Syndrome

    PubMed Central

    Wang, Mingzhe; Li, Mao; Wang, Qiudong; Kwak, Shin; Jiang, Wenfei; Yamamoto, Yoshiharu

    2015-01-01

    We evaluated the effects of acupuncture in patients with restless legs syndrome (RLS) by actigraph recordings. Among the 38 patients with RLS enrolled, 31 (M = 12, F = 19; mean age, 47.2 ± 9.7 years old) completed the study. Patients were treated with either standard acupuncture (n = 15) or randomized acupuncture (n = 16) in a single-blind manner for 6 weeks. Changes in nocturnal activity (NA) and early sleep activity (ESA) between week 0 (baseline), week 2, week 4, and week 6 were assessed using leg actigraph recordings, the International Restless Legs Syndrome Rating Scale (IRLSRS), and Epworth Sleepiness Scale (ESS). Standard but not randomized acupuncture reduced the abnormal leg activity of NA and ESA significantly in week 2, week 4, and week 6 based on the changes in the clinical scores for IRLSRS and ESS in week 4 and week 6 compared with the baseline. No side effects were observed. The results indicate that standard acupuncture might improve the abnormal leg activity in RLS patients and thus is a potentially suitable integrative treatment for long-term use. PMID:25763089

  13. Levodopa for idiopathic restless legs syndrome: evidence-based review.

    PubMed

    Conti, Cristiane Fiquene; de Oliveira, Márcio Moysés; Andriolo, Regis Bruni; Saconato, Humberto; Atallah, Alvaro Nagib; Valbuza, Juliana Spelta; Coin de Carvalho, Luciane Bizari; do Prado, Gilmar Fernandes

    2007-10-15

    Restless legs syndrome (RLS) is a sensory motor disorder characterized by a distressing urge to move the legs and sometimes also other parts of the body usually accompanied by a marked sense of discomfort or pain in the leg or other affected body part. The prevalence of RLS is estimated at 2.7 to 5% of adults and it is more common in women. The treatment of RLS with levodopa has been reported thus a systematic synthesis of evidence is necessary to evaluate the effectiveness and safety of levodopa for RLS. Systematic review of randomized or quasi-randomized, double blind trials on levodopa. Relief of restless legs symptoms marked on a validated scale, subjective sleep quality, sleep quality measured by night polysomnography and actigraphy, quality of life measured by subjective measures, adverse events associated with the treatments. Nine eligible clinical trials were included. The subjective analyses of these studies showed contradictory results, although the objective analyses showed that treatment group had a statistically significant improvement of periodic leg movement (PLM) index, favoring the treatment group. The most commonly adverse event seen was gastrointestinal symptoms. The short-term treatment with levodopa was demonstrated effective and safety for PLM, but there was only few trials assessing long-term treatment and the augmentation phenomenon in RLS. Further long-term randomized controlled trials using standard follow-up measurements as the International RLS Study Group Rating Scale are necessary.

  14. Restless legs syndrome: manifestations, treatment and dental implications.

    PubMed

    Friedlander, Arthur H; Mahler, Michael E; Yagiela, John A

    2006-06-01

    The authors reviewed the clinical features, epidemiology, pathogenesis and risk factors, medical management, dental findings and dental management of patients with restless legs syndrome (RLS). The authors conducted a MEDLINE search for the years 2000 through 2004 using the key terms "restless legs syndrome," "epidemiology," "pathophysiology," "treatment" and "dentistry." They selected articles published in English in peer-reviewed journals for further review, and they gave preference to articles reporting randomized controlled trials. RLS is a neurological disorder that is characterized by unpleasant sensations in the legs that occur at rest, especially at bedtime. These symptoms cause an irresistible urge to get out of bed and move the legs to relieve the discomfort, thereby delaying sleep onset and resulting in fatigue and dysphoria the next day. The prevalence of dental disease may be extensive in patients with RLS because of diminished salivary flow resulting from the medications used to treat RLS. Patient education, saliva substitutes and anticaries agents are indicated. Special precautions must be taken when prescribing or administering sedative-hypnotic agents that are likely to have adverse reactions with the medications used to treat RLS.

  15. New concepts in the management of restless legs syndrome.

    PubMed

    Garcia-Borreguero, Diego; Cano-Pumarega, Irene

    2017-02-27

    Restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED) is a neurological condition with an overall prevalence in adults of 5-10% in Europe and North America. It is characterised by strong feelings of restlessness and distressing paraesthesia-like sensations in the lower legs, particularly when at rest. The symptoms vary considerably in severity and frequency. RLS/WED has a variable clinical expression influenced by genetic, environmental, and medical factors. Research into the pathophysiology of RLS/WED has found that various genetic markers and existing dysfunctions in dopaminergic mechanisms and iron mechanisms play a central role. Until recently, the first line treatment of RLS/WED was with low dose dopamine agonists, with three drugs having been approved by the US Food and Drug Administration and the European Medicines Agency. However, the occurrence of dopaminergic augmentation and an overall increase in severity of symptoms during long term treatment with dopamine agonists is leading to a shift towards non-dopaminergic alternatives as initial treatments, and particularly to α2δ ligands. Recent international guidelines recommend, whenever possible, to start treatment with these drugs (α2δ ligands) to avoid augmentation from the start. Other (eg, glutamatergic or adenosine) neurotransmitters might also play an important role in causing RLS/WED and might thus lead to new treatments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Neuropathy in a cohort of restless leg syndrome patients.

    PubMed

    Bastia, Jogendra K; Bhoi, Sanjeev K; Kalita, Jayantee; Misra, Usha K

    2015-08-01

    This study aims to evaluate the types of neuropathy in a cohort of restless leg syndrome (RLS) patients and compare them with primary RLS. RLS symptoms can occur in peripheral neuropathy and may cause diagnostic confusion, and there is a paucity of studies comparing neuropathic RLS and primary RLS. Patients with RLS diagnosed according to the international restless legs syndrome study group criteria were categorized as primary RLS or secondary. Those with evidence of peripheral neuropathy were categorized as neuropathic RLS. The demographic, clinical, laboratory profile and therapeutic response to dopamine agonists at 6 months and 1 year of neuropathic RLS patients were compared between primary and secondary RLS patients. There were 82 patients with RLS of whom 22 had peripheral neuropathy and 28 had primary RLS. The etiology of neuropathic RLS was diabetes mellitus in 13, renal failure in six, hypothyroidism in five, demyelinating in two, nutritional deficiency in three, leprosy in one, and miscellaneous etiologies in four patients. The neuropathic RLS patients were older (46.0±14.1 versus 35.8±15.4 years), had shorter duration of illness (1.4±1.4 versus 6.2±6.2 years) and were more frequently symptomatic. RLS symptoms were asymmetric in primary RLS patients compared to neuropathic RLS (25% versus 0%). The therapeutic response was similar in both groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Is There an Association between Restless Legs Syndrome and Urticaria?

    PubMed Central

    2016-01-01

    Restless legs syndrome (RLS) is a disease characterized by the urge to move the legs and sleep disturbances. Similarly, chronic spontaneous urticaria (CSU) is a dermatological disease characterized by pruritus and sleep disorders. In this study, we aimed to determine the prevalence and severity of RLS in patients with chronic spontaneous urticaria (CSU) and to compare the quality of sleep of patients with and without RLS in the CSU group using the Pittsburgh Sleep Quality Index. A total of 130 patients with CSU and 100 healthy controls were included in this study. The frequency of RLS, frequency of sleep disturbances, and average score of RLS in patients with CSU were statistically significantly higher than control groups (respectively P = 0.008, P = 0.009, P = 0.004). Subjective sleep quality, sleep latency and habitual sleep efficiency scores in patients with RLS were statistically significantly higher than patients without RLS (respectively P = 0.016, P = 0.007, P = 0.035). We claimed that pruritus of urticaria may decrease the quality of sleep in patients with RLS and it may trigger and worsen the restless legs syndrome. Furthermore, RLS and CSU may share a common etiology. PMID:27134503

  18. Transgenic expression of BRCA1 disturbs hematopoietic stem and progenitor cells quiescence and function

    SciTech Connect

    Bai, Lin; Shi, Guiying; Zhang, Xu; Dong, Wei; Zhang, Lianfeng

    2013-10-15

    The balance between quiescence and proliferation of HSCs is an important regulator of hematopoiesis. Loss of quiescence frequently results in HSCs exhaustion, which underscores the importance of tight regulation of proliferation in these cells. Studies have indicated that cyclin-dependent kinases are involved in the regulation of quiescence in HSCs. BRCA1 plays an important role in the repair of DNA double-stranded breaks, cell cycle, apoptosis and transcription. BRCA1 is expressed in the bone marrow. However, the function of BRCA1 in HSCs is unknown. In our study, we generated BRCA1 transgenic mice to investigate the effects of BRCA1 on the mechanisms of quiescence and differentiation in HSCs. The results demonstrate that over-expression of BRCA1 in the bone marrow impairs the development of B lymphocytes. Furthermore, BRCA1 induced an increase in the number of LSKs, LT-HSCs, ST-HSCs and MPPs. A competitive transplantation assay found that BRCA1 transgenic mice failed to reconstitute hematopoiesis. Moreover, BRCA1 regulates the expression of p21{sup waf1}/cip1 and p57{sup kip2}, which results in a loss of quiescence in LSKs. Together, over-expression of BRCA1 in bone marrow disrupted the quiescent of LSKs, induced excessive accumulation of LSKs, and disrupted differentiation of the HSCs, which acts through the down-regulated of p21{sup waf1}/cip1 and p57{sup kip2}. - Highlights: • Over-expression of BRCA1 results in impaired B lymphocyte development. • BRCA1 transgenic mice disrupted the quiescent of LSKs, induced excessive accumulation of LSKs. • BRCA1 impairs the function of HSCs through the down-regulated of p21{sup waf1/cip1} and p57{sup kip2}.

  19. The onset of seasonal quiescence in the female Bennett's wallaby (Macropus rufogriseus rufogriseus).

    PubMed

    Curlewis, J D; White, A S; Loudon, A S

    1987-05-01

    The breeding season of the non-lactating Bennett's wallaby terminates when animals enter the state of seasonal quiescence. To examine this transition, pouch young were removed from females at intervals which were 3, 4 or 8 weeks (6, 11 and 8 animals respectively) after the winter solstice. Within 48 days, 3, 1 and 1 females gave birth respectively, indicating that these animals were not in seasonal quiescence when pouch young were removed. Those animals which did not give birth were either in seasonal quiescence or had undergone a non-pregnant cycle. To differentiate between the 2 possibilities, techniques which would ensure the detection of pregnant and non-pregnant cycles were assessed in 8 females during the breeding season. As has been previously reported for the wallaby, changes in peripheral progesterone concentrations and the vaginal smear occurred during pregnant and non-pregnant reproductive cycles. In addition, mating was detected by marking the male with a mixture of coloured crayon and paraffin wax. It was concluded that reproductive cycles in female wallabies could be monitored by collecting blood samples 2 times each week for progesterone determination and daily examination of females for mating marks. These techniques were then used to study the onset of seasonal quiescence in 9 females. All animals continued to show reproductive cycles after the winter solstice and it was not until 10 weeks after the winter solstice that all animals were in seasonal quiescence. This represents an increase in the duration of the breeding season over that previously reported for this species.

  20. Vascular risk factors, cardiovascular disease and restless legs syndrome in women

    PubMed Central

    Winter, Anke C.; Schürks, Markus; Glynn, Robert J; Buring, Julie E.; Gaziano, J. Michael; Berger, Klaus; Kurth, Tobias

    2013-01-01

    Background Previous studies evaluating the association between cardiovascular disease and vascular risk factors with restless legs syndrome showed inconsistent results, especially for the potential relation between various vascular risk factors and restless legs syndrome. We therefore aimed to analyze the relationship between vascular risk factors, prevalent cardiovascular disease and restless legs syndrome. Methods This is a cross-sectional study of 30,262 female health professionals participating in the Women's Health Study (WHS). Restless legs syndrome was defined according to diagnostic criteria of the International Restless Legs Study Group. Information on vascular risk factors (diabetes, hypertension, hypercholesterolemia, body mass index, alcohol, smoking, exercise, family history of myocardial infarction) was self-reported. Cardiovascular disease events (coronary revascularization, myocardial infarction, stroke) were confirmed by medical record review. Prevalent major cardiovascular disease was defined as non-fatal stroke or non-fatal myocardial infarction. Logistic regression models were used to evaluate the association between vascular risk factors, prevalent cardiovascular disease and restless legs syndrome. Results Of the 30,262 participants (mean age: 63.6 years), 3,624 (12.0%) reported restless legs syndrome. In multivariable-adjusted models, body mass index (OR for BMI ≥35kg/m2: 1.35, 95% CI: 1.17–1.56), diabetes (OR: 1.19, 95%CI: 1.04–1.35), hypercholesterolemia (OR: 1.17, 95% CI: 1.09–1.26), smoking status (OR for ≥15 cigarettes/day: 1.41, 95%CI: 1.19–1.66) and exercise (OR for exercise ≥ 4 times/week: 0.84, 95%CI: 0.74–0.95) were associated with restless legs syndrome prevalence. We found no association between prevalent cardiovascular disease (major cardiovascular disease, myocardial infarction, stroke) and restless legs syndrome prevalence. Women who underwent coronary revascularization had a multivariable-adjusted OR of 1.39 (1

  1. Restless legs syndrome: a qualitative analysis of psychosocial suffering and interdisciplinary attention.

    PubMed

    Varela, Maria José V; Coin-Carvalho, João E; Carvalho, Luciane B C; Varela, Maite V; Potasz, Clarisse; Prado, Lucila B F; do Prado, Gilmar F

    2013-10-01

    The aim of this study is to investigate psychosocial factors related to the diagnosis and treatment of patients with restless legs syndrome. Fifteen patients were interviewed at the Neuro-Sono Outpatient Clinic, Universidade Federal de São Paulo. The results were submitted to a qualitative analysis. We identified four content categories: illness description, illness history, illness experience, and relationships. Lack of control over the body and lack of recognition by professionals produce stigma and lead patients to suffering. The research underscores the relevance of psychosocial factors to the diagnosis and treatment of patients with restless legs syndrome and the importance of having interdisciplinary teams when attending patients with restless legs syndrome.

  2. Pathological gambling plus hypersexuality in restless legs syndrome: a new case.

    PubMed

    d'Orsi, Giuseppe; Demaio, Vincenzo; Specchio, L M

    2011-08-01

    Emerging clinical data indicate that dopaminergic agonists used to treat restless legs syndrome may be associated with dopamine dysregulation syndrome, particularly pathological gambling. We report a new case with pathological gambling plus hypersexuality and impotence in an old patient treated with a small dose (0.18 mg daily at bedtime) of pramipexole for restless legs syndrome for 5 months. The time relationship and the resolution upon discontinuation of dopaminergic agonists suggest a causative association. Our new case confirms that restless legs syndrome patients should be cautioned about potential dopamine dysregulation syndrome coinciding with dopaminergic agonists, as it can be reversed by drug withdrawal.

  3. Characterizing restless legs syndrome and leg motor restlessness in patients with Parkinson's disease: A multicenter case-controlled study.

    PubMed

    Suzuki, Keisuke; Okuma, Yasuyuki; Uchiyama, Tomoyuki; Miyamoto, Masayuki; Sakakibara, Ryuji; Shimo, Yasushi; Hattori, Nobutaka; Kuwabara, Satoshi; Yamamoto, Toshimasa; Kaji, Yoshiaki; Hirano, Shigeki; Numao, Ayaka; Hirata, Koichi

    2017-08-14

    We investigated the prevalence and impact of restless legs syndrome (RLS) and leg motor restlessness (LMR) in patients with Parkinson's disease (PD) in a multicenter study. A total of 436 PD patients and 401 age- and sex-matched controls were included in this study. RLS was diagnosed based on four essential features. LMR was diagnosed when a participant exhibited the urge to move his or her legs but did not meet the four essential features of RLS. The RLS prevalence did not differ between PD patients and controls (3.4% vs. 2.7%), while LMR prevalence was significantly higher in PD patients than in controls (12.8% vs. 4.5%). PD patients with RLS or LMR had a higher prevalence of excessive daytime sleepiness (EDS) (50.7%, vs. 6.9%), probable REM sleep behavior disorder (38.0% vs. 3.4%) and PD-related sleep problems (49.3% vs. 20.7%) than controls with RLS or LMR. RLS/LMR preceding PD onset was related to an older age of PD onset. Our study revealed an increased prevalence of LMR but not RLS in PD patients. LMR could be an early manifestation of PD; however, whether LMR is within the range of RLS or whether LMR and RLS constitute different entities in PD requires further studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Restless legs syndrome in Korean patients with drug-naïve Parkinson's disease: a nation-wide study.

    PubMed

    Shin, Hee-Young; Youn, Jinyoung; Yoon, Won Tae; Kim, Ji Sun; Cho, Jin Whan

    2013-03-01

    Restless legs syndrome is a common neurologic disorder, and there is increasing evidence for a dopaminergic link between Parkinson's disease and restless legs syndrome. However, most previous studies did not take into account the effects of dopaminergic medication. We conducted a nation-wide, cross-sectional study to determine the prevalence and clinical characteristics of restless legs syndrome in Korean drug-naïve Parkinson's disease patients. One hundred and fifty-one drug-naïve patients with Parkinson's disease were enrolled from 18 centers in South Korea over the course of one year. Clinical profiles of parkinsonism, restless legs syndrome, psychiatric symptoms, and laboratory data were collected. The findings of subjects with and without restless legs syndrome were compared. The prevalence of restless legs syndrome in drug-naïve patients with Parkinson's disease was 16.5%. Subjects with restless legs syndrome had a higher mean Hoehn and Yahr stage and more severe limb parkinsonism, especially tremor. There was, however, no difference in iron metabolism between patients with and without restless legs syndrome. Analysis demonstrated that Beck's depression inventory score was associated with the severity of restless legs syndrome. Our study demonstrated an increased prevalence of restless leg syndrome in drug-naïve patients with Parkinson's disease than in the general population. Based on the association between parkinsonism and restless legs syndrome, and the unique characteristics of restless legs syndrome in patients with Parkinson's disease, we suggest that the pathophysiology of restless legs syndrome in Parkinson's disease differs from that in patients without Parkinson's disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Insulin, cGMP, and TGF-beta signals regulate food intake and quiescence in C. elegans: a model for satiety.

    PubMed

    You, Young-jai; Kim, Jeongho; Raizen, David M; Avery, Leon

    2008-03-01

    Despite the prevalence of obesity and its related diseases, the signaling pathways for appetite control and satiety are not clearly understood. Here we report C. elegans quiescence behavior, a cessation of food intake and movement that is possibly a result of satiety. C. elegans quiescence shares several characteristics of satiety in mammals. It is induced by high-quality food, it requires nutritional signals from the intestine, and it depends on prior feeding history: fasting enhances quiescence after refeeding. During refeeding after fasting, quiescence is evoked, causing gradual inhibition of food intake and movement, mimicking the behavioral sequence of satiety in mammals. Based on these similarities, we propose that quiescence results from satiety. This hypothesized satiety-induced quiescence is regulated by peptide signals such as insulin and TGF-beta. The EGL-4 cGMP-dependent protein kinase functions downstream of insulin and TGF-beta in sensory neurons including ASI to control quiescence in response to food intake.

  6. Size-frequency distribution of gamma ray bursts from thermonuclear runaway on neutron stars accreting interstellar gas

    SciTech Connect

    Higdon, J.C.; Lingenfelter, R.E.

    1984-05-26

    We present some preliminary results of calculations we have made suggesting that runaway thermonuclear burning of interstellar gas accreted onto magnetic neutron stars can account for the observed size-frequency distribution of gamma ray bursts.

  7. Oscillations During Thermonuclear X-ray Bursts: A New Probe of Neutron Stars

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Observations of thermonuclear (also called Type 1) X-ray bursts from neutron stars in low mass X-ray binaries (LMXB) with the Rossi X-ray Timing Explorer (RXTE) have revealed large amplitude, high coherence X-ray brightness oscillations with frequencies in the 300 - 600 Hz range. Substantial spectral and timing evidence point to rotational modulation of the X-ray burst flux as the cause of these oscillations, and it is likely that they reveal the spin frequencies of neutron stars in LMXB from which they are detected. Here we review the status of our knowledge of these oscillations and describe how they can be used to constrain the masses and radii of neutron stars as well as the physics of thermonuclear burning on accreting neutron stars.

  8. A review of the thermonuclear runaway model of a nova outburst

    NASA Technical Reports Server (NTRS)

    Sparks, W. M.; Starrfield, S.; Truran, J. W.

    1977-01-01

    Kraft's (1963) model for a nova outburst caused by a thermonuclear runaway in the hydrogen-rich matter accreted onto the white dwarf in a binary system is reviewed. Hydrostatic and hydrodynamic studies of this phenomenon are summarized, analyses of shock ejection based on hydrodynamic computer codes are discussed, and one specific hydrodynamic code is outlined. Results obtained with this code are presented and evaluated for an initial model containing a white dwarf with a hydrogen-rich envelope of 0.0001 to 0.001 solar mass in hydrostatic and thermal equilibrium. It is shown that an implicit hydrodynamic computer code is required in order to study the thermonuclear-runaway phenomenon. The early evolution of three models with different intrinsic luminosities is illustrated, and enhancement of CNO nuclei at the bottom of the hydrogen-rich envelope is investigated. It is suggested that the concentration of C-13, N-15, and O-17 should be greatly enhanced in nova ejecta.

  9. Compression and combustion of non-cryogenic targets with a solid thermonuclear fuel for inertial fusion

    SciTech Connect

    Gus'kov, S. Yu.; Zmitrenko, N. V.; Sherman, V. E.

    2013-04-15

    Variants of a target with a solid thermonuclear fuel in the form of deuterium-tritium hydrides of light metals for an inertial fusion have been proposed. The laser-pulse-induced compression of non-cryogenic targets, as well as ignition and combustion of such targets, has been examined. The numerical calculations show that, despite a decrease in the caloric content of the fuel and an increase in the energy losses on intrinsic radiation in the target containing deuterium-tritium hydrides of light metals as compared to the target containing deuterium-tritium ice, the non-cryogenic target can ensure the fusion gain sufficient for its use in the energy cycle of a thermonuclear power plant based on the inertial plasma confinement method.

  10. Compression and combustion of non-cryogenic targets with a solid thermonuclear fuel for inertial fusion

    NASA Astrophysics Data System (ADS)

    Gus'kov, S. Yu.; Zmitrenko, N. V.; Sherman, V. E.

    2013-04-01

    Variants of a target with a solid thermonuclear fuel in the form of deuterium-tritium hydrides of light metals for an inertial fusion have been proposed. The laser-pulse-induced compression of non-cryogenic targets, as well as ignition and combustion of such targets, has been examined. The numerical calculations show that, despite a decrease in the caloric content of the fuel and an increase in the energy losses on intrinsic radiation in the target containing deuterium-tritium hydrides of light metals as compared to the target containing deuterium-tritium ice, the non-cryogenic target can ensure the fusion gain sufficient for its use in the energy cycle of a thermonuclear power plant based on the inertial plasma confinement method.

  11. Frontiers in propulsion research: Laser, matter-antimatter, excited helium, energy exchange thermonuclear fusion

    NASA Technical Reports Server (NTRS)

    Papailiou, D. D. (Editor)

    1975-01-01

    Concepts are described that presently appear to have the potential for propulsion applications in the post-1990 era of space technology. The studies are still in progress, and only the current status of investigation is presented. The topics for possible propulsion application are lasers, nuclear fusion, matter-antimatter annihilation, electronically excited helium, energy exchange through the interaction of various fields, laser propagation, and thermonuclear fusion technology.

  12. A Deep Search for Prompt Radio Emission from Thermonuclear Supernovae with the Very Large Array

    NASA Astrophysics Data System (ADS)

    Chomiuk, Laura; Soderberg, Alicia M.; Chevalier, Roger A.; Bruzewski, Seth; Foley, Ryan J.; Parrent, Jerod; Strader, Jay; Badenes, Carles; Fransson, Claes; Kamble, Atish; Margutti, Raffaella; Rupen, Michael P.; Simon, Joshua D.

    2016-04-01

    Searches for circumstellar material around Type Ia supernovae (SNe Ia) are some of the most powerful tests of the nature of SN Ia progenitors, and radio observations provide a particularly sensitive probe of this material. Here, we report radio observations for SNe Ia and their lower-luminosity thermonuclear cousins. We present the largest, most sensitive, and spectroscopically diverse study of prompt ({{Δ }}t≲ 1 years) radio observations of 85 thermonuclear SNe, including 25 obtained by our team with the unprecedented depth of the Karl G. Jansky Very Large Array. With these observations, SN 2012cg joins SN 2011fe and SN 2014J as an SN Ia with remarkably deep radio limits and excellent temporal coverage (six epochs, spanning 5-216 days after explosion, implying \\dot{M}/{v}w≲ 5× 10-9 M⊙) yr-1/(100 km s-1), assuming ɛB = 0.1 and ɛe = 0.1). All observations yield non-detections, placing strong constraints on the presence of circumstellar material. We present analytical models for the temporal and spectral evolution of prompt radio emission from thermonuclear SNe as expected from interaction with either wind-stratified or uniform density media. These models allow us to constrain the progenitor mass loss rates, with limits in the range of \\dot{M}≲ 10-9-10-4 M⊙ yr-1, assuming a wind velocity of vw = 100 km s-1. We compare our radio constraints with measurements of Galactic symbiotic binaries to conclude that ≲10% of thermonuclear SNe have red giant companions.

  13. The historical record for Sirius - Evidence for a white-dwarf thermonuclear runaway?

    NASA Technical Reports Server (NTRS)

    Bruhweiler, Frederick C.; Kondo, Yoji; Sion, Edward M.

    1986-01-01

    Evidence was recently presented that in medieval times Sirius was a bright red star, rather than the present bluish-white star. Here, the results of attempts to detect possible planetary nebula ejecta toward Sirius using data obtained by the IUE are presented. Based on these results and in the light of recent advances in understanding white-dwarf evolution, it is proposed that Sirius B underwent a recent thermonuclear runaway event triggered by a diffusion-induced CN reaction.

  14. MILLIHERTZ QUASI-PERIODIC OSCILLATIONS AND THERMONUCLEAR BURSTS FROM TERZAN 5: A SHOWCASE OF BURNING REGIMES

    SciTech Connect

    Linares, M.; Chakrabarty, D.; Altamirano, D.; Cumming, A.; Keek, L.

    2012-04-01

    We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J17480-2446, located in the globular cluster Terzan 5. The increase in burst rate that we found during its 2010 outburst, when persistent luminosity rose from 0.1 to 0.5 times the Eddington limit, is in qualitative agreement with thermonuclear burning theory yet contrary to all previous observations of thermonuclear bursts. Thermonuclear bursts gradually evolved into a mHz QPO when the accretion rate increased, and vice versa. The mHz QPOs from IGR J17480-2446 resemble those previously observed in other accreting NSs, yet they feature lower frequencies (by a factor {approx}3) and occur when the persistent luminosity is higher (by a factor 4-25). We find four distinct bursting regimes and a steep (close to inverse cubic) decrease of the burst recurrence time with increasing persistent luminosity. We compare these findings to nuclear burning models and find evidence for a transition between the pure helium and mixed hydrogen/helium ignition regimes when the persistent luminosity was about 0.3 times the Eddington limit. We also point out important discrepancies between the observed bursts and theory, which predicts brighter and less frequent bursts, and suggest that an additional source of heat in the NS envelope is required to reconcile the observed and expected burst properties. We discuss the impact of NS magnetic field and spin on the expected nuclear burning regimes, in the context of this particular pulsar.

  15. Rocket propulsion by thermonuclear micro-bombs ignited with intense relativistic electron beams.

    NASA Technical Reports Server (NTRS)

    Winterberg, F.

    1971-01-01

    Discussion of a method for the ignition of a thermonuclear microbomb by means of an intense relativistic electron beam with regard to its potential application to rocket propulsion. With such a system, exhaust velocities up to 1000 km/sec, corresponding to a specific impulse of 100,000 sec, seem to be within the realm of possibility. The rocket is propelled by a chain of thermonuclear microbombs exploded in a concave magnetic mirror produced by superconducting field coils. The magnetic pressure of the field reflects the fireball generated by the explosion. For the large capacitor bank required to generate the intense relativistic electron beam, a desirable lightweight design may be possible through use of ferroelectric materials. Because of the high cost of the T-D and He 3-D thermonuclear material, the system has to be optimized by minimizing the T-D and He 3-D consumption by a proper TD and He 3-D fuel to hydrogen propellant mass ratio, leading to a larger total system mass than would be absolutely necessary.

  16. Rocket propulsion by thermonuclear micro-bombs ignited with intense relativistic electron beams.

    NASA Technical Reports Server (NTRS)

    Winterberg, F.

    1971-01-01

    Discussion of a method for the ignition of a thermonuclear microbomb by means of an intense relativistic electron beam with regard to its potential application to rocket propulsion. With such a system, exhaust velocities up to 1000 km/sec, corresponding to a specific impulse of 100,000 sec, seem to be within the realm of possibility. The rocket is propelled by a chain of thermonuclear microbombs exploded in a concave magnetic mirror produced by superconducting field coils. The magnetic pressure of the field reflects the fireball generated by the explosion. For the large capacitor bank required to generate the intense relativistic electron beam, a desirable lightweight design may be possible through use of ferroelectric materials. Because of the high cost of the T-D and He 3-D thermonuclear material, the system has to be optimized by minimizing the T-D and He 3-D consumption by a proper TD and He 3-D fuel to hydrogen propellant mass ratio, leading to a larger total system mass than would be absolutely necessary.

  17. Restless leg syndrome exacerbated by amytriptiline in a patient with Duchenne Muscular Dystrophy.

    PubMed

    Akamine, Ricardo Tera; Grossklauss, Luis Fernando; Nozoe, Karen Tieme; Moreira, Gustavo Antonio; Bulle Oliveira, Acary Souza; Troccoli Chieia, Marco Antônio; Andersen, Monica Levy; Tufik, Sergio

    2014-09-01

    We report an unusual case of a Duchenne Muscular Dystrophy(DMD) patient who initiated a restless leg syndrome after the use of amytriptiline. The prescription and use of this medication for patients with persistent neuropathic pain is relatively common, especially for patients with DMD. Normally, this medication is well tolerated, however, we now report the occurrence of an induction or intensification of a restless leg syndrome case in a young patient with DMD, treated with amytriptiline for his chronic pain.

  18. Novel assessment of microvascular changes in idiopathic restless legs syndrome (Willis-Ekbom disease).

    PubMed

    Anderson, Kirstie N; Di Maria, Costanzo; Allen, John

    2013-06-01

    Many patients with restless legs syndrome (Willis-Ekbom disease) complain of burning sensations in their feet associated with the desire to move, such that they seek cooler environments. This pilot study aimed to characterise the microvascular skin changes in 12 patients with restless legs syndrome compared with 12 age- and sex-matched controls. Patients with moderate or severe restless legs syndrome and controls underwent detailed thermovascular assessment in a controlled temperature room at three different stages (normothermic phase 23 °C, hot phase 30 °C, cold phase 18 °C). Microvascular activity was recorded during all phases by bilateral great toe laser-Doppler flowmetry and also by whole-body thermography. Patient and control measurements were compared. The study protocol was well tolerated. Parameters extracted from the laser-Doppler flowmetry measurements were used to model a logistic function using binary logistic regression. This demonstrated a statistically significant difference between patients with restless legs syndrome and healthy controls (P < 0.001). Visual inspection of the body thermography image sequences showed increased lower limb movement in patients with restless legs syndrome patients compared with controls. Thermography analysis also showed significant differences between foot temperatures in patients with restless legs syndrome compared with controls during the hot phase (P = 0.011). Notably, patients with restless legs syndrome had more uniform foot temperatures, whereas controls had a wider variability in surface temperature across the feet. This novel study demonstrates impaired microvascular circulation in patients with restless legs syndrome in comparison to matched controls and a potential mechanism for the sensation of burning feet. The protocol also provides an experimental paradigm to test therapeutic interventions for the future. © 2013 European Sleep Research Society.

  19. [Practical guidelines for diagnosis and therapy of restless legs syndrome].

    PubMed

    Krenzer, M; Oertel, W; Trenkwalder, C

    2014-01-01

    Restless legs syndrome (RLS) is the most common neurological sleep disorder affecting 10 % of the Caucasian population. The disorder is characterized by painful sensations in the lower limbs, especially during the evening, at night and during rest, resulting in an urge to move the legs and insomnia. As a result the quality of life is significantly reduced. Dopaminergic agents, opioids and anticonvulsants have proven to be effective for RLS with only the former being currently licensed; however, affected patients have to be identified, which is not always the case, especially in outpatient settings. Possible impediments to the adequate management of patients with RLS may include a lack of awareness, comorbidities and other medical conditions mimicking RLS. To overcome some of these difficulties practical guidelines for the diagnosis and therapy of RLS are provided.

  20. Can botulinum toxin put the restless legs syndrome to rest?

    PubMed

    Lim, Erle C H; Seet, Raymond C S

    2007-01-01

    The restless legs syndrome (RLS), affecting between 3% and 15% of the population, is characterised by an urge to move the legs during wakefulness, associated with a range of unpleasant sensory symptoms, especially when sitting or lying down at night. The symptoms can even be painful, and lead to sleep disturbances and depression. RLS is treated with dopaminergic agents, anticonvulsants, opioids, clonidine and benzodiazepines. In a small percentage of cases, RLS is refractory to treatment, requiring combination therapy. Botulinum toxin (BTX), derived from the exotoxin of Clostridium botulinum, cleaves soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, causing chemodenervation of cholinergic neurons. BTX has been demonstrated to ameliorate pain syndromes, possibly by reducing peripheral and central sensitization to pain. We postulate that BTX can be injected subcutaneously to the lower limbs to effect amelioration of the symptoms of RLS.

  1. The biopsychosocial effects of restless legs syndrome (RLS)

    PubMed Central

    Becker, Philip M

    2006-01-01

    The symptoms of restless legs syndrome (RLS) are associated with reductions in patients’ quality of life (QoL) and mental heath. Sleep disturbance, which is often the most troublesome symptom of RLS, may have a negative impact on patients’ daytime cognitive abilities. Research has established a relationship between the symptoms of RLS and mood symptoms, but causality is unclear. Some studies have indicated that the symptoms of RLS precede those of depression or anxiety, and others relate the severity of mood symptoms to the severity of RLS symptoms. Associations between the sleep disturbance produced by RLS and patients’ mood symptoms have also been demonstrated. The impact of RLS symptoms and their treatment on QoL, mental health, and cognition are reviewed herein. PMID:19412498

  2. Restless legs syndrome: diagnosis and review of management options

    PubMed Central

    Byrne, Ruth; Sinha, Smita; Chaudhuri, K Ray

    2006-01-01

    Restless legs syndrome (RLS) is one of the commonest movement disorders affecting sleep and also daytime functioning. The prevalence may be 8%–10% of the white Caucasian population. The diagnosis is simple and is based on a well-validated clinical questionnaire, yet misdiagnosis is common and the condition remains underdiagnosed and consequently inappropriately treated, often causing great distress to the sufferers. In spite of robust evidence for effective treatment of RLS, patients may often be told to “put up with the symptoms” and suffer the consequence of years of poor sleep which may lead to major lifestyle changes. This review addresses the diagnostic issues, the differential diagnosis, and the evidence base for treatment of the common condition. PMID:19412460

  3. Living with Restless Legs Syndrome/Willis-Ekbom Disease.

    PubMed

    Tachibana, Naoko

    2015-09-01

    Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is commonly seen in patients with end-stage renal disease (ESRD), but this condition has not been properly recognized. The prevalence of RLS/WED in ESRD shows the ethnic variation (7%-68%), with the similar tendency of primary RLS/WED. Although RLS/WED in ESRD is defined in secondary RLS/WED, the factors of ESRD that are involved in the genesis of RLS/WED remain unknown. Even after renal transplantation, RLS/WED symptoms do not completely disappear, and genetic predisposition to RLS/WED may play an important role in causing RLS/WED. Long-term intervention for RLS/WED and ESRD will be necessary. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Restless Legs Syndrome/Willis-Ekbom Disease and Pregnancy.

    PubMed

    Prosperetti, Chiara; Manconi, Mauro

    2015-09-01

    Restless legs syndrome (RLS)/Willis-Ekbom disease is 3-fold more prevalent in pregnant than in non-pregnant women. Symptoms are particularly strong and frequent during the third trimester of pregnancy and disappear around delivery. A pre-existing form of RLS tends to worsen during pregnancy. Women who experience RLS during pregnancy have a higher risk of symptoms in further pregnancies and of developing a primary form of RLS later in life, than women free of symptoms during pregnancy. This article reviews the literature for pregnancy-related RLS, with particular attention to its epidemiology, course, possible mechanisms, management, and the impact of symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Restless legs syndrome and periodic limb movement disorder.

    PubMed

    Parker, Kathy P; Rye, David B

    2002-12-01

    Restless leg syndrome and PLMD are nocturnal movement disorders associated with significant adverse effects on the health and well-being of patients and their families [66]. Although the pathophysiological basis remains to be fully described, current research points to abnormalities in CNS function and neurotransmitter systems. The accurate diagnosis of RLS and PMD requires a thorough history, physical examination, diagnostic tests, and often, a referral to a sleep disorders specialist. Considering the prevalence of these conditions and their negative impact, nurses should be well-versed in the assessment and management of these problems as well as in the appropriate education of patients and their families. Nursing research is greatly needed, particularly with regard to the development and testing of biobehavioral interventions designed to decrease associated symptoms and improve clinical outcomes. Finally, because of the complexity of the clinical presentation of RLS and PLMD, this population of patients presents nurse clinicians and researchers alike with an extraordinary opportunity for interdisciplinary collaboration.

  6. Differentiating nocturnal leg cramps and restless legs syndrome.

    PubMed

    Rana, Abdul Qayyum; Khan, Fatima; Mosabbir, Abdullah; Ondo, William

    2014-07-01

    Leg pain and discomfort are common complaints in any primary physician's clinic. Two common causes of pain or discomfort in legs are nocturnal leg cramps (NLC) and restless leg syndrome (RLS). NLC present as painful and sudden contractions mostly in part of the calf. Diagnosis of NLC is mainly clinical and sometimes involves investigations to rule out other mimics. RLS is a condition characterized by the discomfort or urge to move the lower limbs, which occurs at rest or in the evening/night. The similarity of RLS and leg cramps poses the issue of errors in diagnosing and differentiating the two. In this paper we review the pathopysiology of each entity and their diagnosis as well as treatment. The two conditions are then compared to appreciate the differences and similarities. Finally, suggestions are recommended for complete assessment.

  7. Restless legs syndrome: a review of clinical and pathophysiologic features.

    PubMed

    Allen, R P; Earley, C J

    2001-03-01

    Restless legs syndrome (RLS), although long ignored and still much underdiagnosed, disrupts the life and sleep considerably of those who have it. Recent clinical and basic research provides for better definition and pathophysiologic understanding of the disorder. The body of knowledge about this disorder has been expanding rapidly during the past decade and it has altered our concepts of this disorder. This review of RLS covers history, diagnosis, morbidity of sleep disturbance, relation to periodic limb movements in both sleep and waking, secondary causes, severity assessment methods, phenotypes for possible genetic patterns, epidemiology, pathophysiology, and medical treatment considerations. The emphasis on pathophysiology includes consideration of central nervous system localization, neurotransmitter and other systems involved, and the role of iron metabolism. Studies to date support the authors' recently advanced iron-dopamine model of RLS.

  8. Iron's role in paediatric restless legs syndrome - a review.

    PubMed

    Dosman, Cara; Witmans, Manisha; Zwaigenbaum, Lonnie

    2012-04-01

    Paediatric restless legs syndrome (RLS) treatment is important because RLS's associated sleep disturbance causes significant developmental-behavioural morbidity and impacts family well-being. RLS is associated with brain iron insufficiency and dopaminergic dysfunction. Diagnosis requires fulfillment of diagnostic criteria, which for children are currently in evolution, and have limitations, especially in preschoolers. The community physician needs to recognize the possibility of RLS to refer to a sleep specialist for diagnostic confirmation and management recommendations, which include oral iron therapy, even though there is currently no definitive research evidence for iron efficacy in most children with RLS. A 3 mg to 6 mg elemental iron/kg/day dose for three months could be tried if the ferritin level is <50 ug/L. Sleep hygiene and behavioural strategies are also recommended. Iron supplementation should be safe in the absence of iron metabolism disorders, provided that transferrin saturation and ferritin levels are monitored pre-and post-treatment.

  9. Lack of the ubiquitin-editing enzyme A20 results in loss of hematopoietic stem cell quiescence

    PubMed Central

    Nakagawa, Masahiro Marshall; Thummar, Keyur; Mandelbaum, Jonathan; Pasqualucci, Laura

    2015-01-01

    A balance between quiescence and proliferation is critical for proper maintenance of the hematopoietic stem cell (HSC) pool. Although a lot is known about hematopoiesis, molecular mechanisms that control HSC quiescence remain largely unknown. The ubiquitin-editing enzyme A20 functions as a central regulator of inflammation and adaptive immunity. Here, we show that a deficiency of A20 in the hematopoietic system causes anemia, lymphopenia, and postnatal lethality. Lack of A20 in HSCs results in diminished pool size, impaired radioprotection, defective repopulation, and loss of quiescence. A20-deficient HSCs display increased IFN-γ signaling, caused by augmented NF-κB activation. Strikingly, deletion of both IFN-γ and A20 in hematopoietic cells results in partial rescue of the HSC phenotype. We anticipate that our experiments will facilitate the understanding of mechanisms through which A20-mediated inflammatory signals control HSC quiescence and functions. PMID:25624445

  10. Ferric carboxymaltose in patients with restless legs syndrome and nonanemic iron deficiency: A randomized trial.

    PubMed

    Trenkwalder, Claudia; Winkelmann, Juliane; Oertel, Wolfgang; Virgin, Garth; Roubert, Bernard; Mezzacasa, Anna

    2017-06-23

    Compromised iron status is important in restless legs syndrome pathophysiology. We compared the efficacy and tolerability of ferric carboxymaltose (single intravenous dose) versus placebo for restless legs syndrome treatment in iron-deficient nonanemic patients. Patients with moderate to severe restless legs syndrome and serum ferritin < 75 μg/L (or serum ferritin 75-300 μg/L and transferrin saturation < 20%) were randomized to ferric carboxymaltose (1000 mg iron) or placebo. Mean change difference between ferric carboxymaltose and placebo in International Restless Legs Syndrome Severity Scale score from baseline to week 4 was the primary end point; week 12 was a secondary end point. Ferric carboxymaltose treatment (n = 59) led to nonsignificant improvement over placebo (n = 51) in International Restless Legs Syndrome Severity Scale score at week 4 (difference [95% confidence interval], -2.5 [-5.93 to 1.02], P = 0.163), reaching significance by week 12 (-4.66 [-8.59 to -0.73], P = 0.021). In patients who responded to treatment, ferric carboxymaltose may require more time to stabilize restless legs syndrome than previously assumed. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

  11. Association of restless legs syndrome, pain, and mood disorders in Parkinson's disease.

    PubMed

    Rana, Abdul Qayyum; Qureshi, Abdul Rehman M; Rahman, Labiba; Jesudasan, Ajantha; Hafez, Kevin K; Rana, Mohammad A

    2016-01-01

    The objectives of the study were to analyze the association between Parkinson's disease and restless legs syndrome, and to explore the relationship between mood disorder comorbidity (anxiety and depression), pain, and restless legs syndrome. This study included 123 Parkinson's disease patients and 123 non-Parkinson's disease patients matched for age and gender, and evaluated for anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence. This was performed using semi-structured interviews and a neurological examination through the restless legs syndrome diagnostic criteria and the following inventories; Hospital Anxiety and Depression Scale, Brief Pain Inventory, and Pain Disability Index. Parkinson's disease patients had significantly greater anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence in comparison to controls. In addition, Parkinson's disease patients' comorbid for anxiety and depression had significantly greater pain severity, pain interference, and pain disability, but not RLS prevalence, in comparison to Parkinson's disease only, Parkinson's disease anxiety, and Parkinson's disease depression patients. Pain interference, pain severity, and pain disability is greater among Parkinson's disease patients with anxiety and depression, in comparison to Parkinson's disease patients without anxiety and depression. On the contrary, the prevalence of restless legs syndrome was not found to be relevant.

  12. Silent Cerebral Small Vessel Disease in Restless Legs Syndrome

    PubMed Central

    Ferri, Raffaele; Cosentino, Filomena I.I.; Moussouttas, Michael; Lanuzza, Bartolo; Aricò, Debora; Bagai, Kanika; Wang, Lily; McLaughlin, BethAnn; Walters, Arthur S.

    2016-01-01

    Study Objectives: Growing literature suggests that patients with restless legs syndrome (RLS) may be at increased risk for hypertension, heart disease, and stroke. Cerebral small vessel disease (SVD) is a known risk factor for clinical stroke. This study evaluated silent cerebral SVD by MRI in patients with RLS, in the absence of a history of previous clinical stroke or known stroke risk factors and taking into account disease duration. Methods: Fifty-three patients with RLS < 10 y were prospectively recruited along with 44 with RLS > 10 y and 74 normal controls. A magnetic resonance imaging study was obtained from all subjects and scans were analyzed for area and volume of SVD. Results: There was a significant increase in SVD area in the entire group of RLS patients compared to controls (P = 0.036); this was almost entirely driven by the group with RLS > 10 y. SVD area and volume were significantly increased in patients with RLS > 10 y with respect to both controls (P < 0.0001 and P < 0.0014, respectively) and RLS < 10 y (P < 0.00022 and P < 0.003, respectively). Age, duration of RLS, and the interaction of age and duration of RLS were independent predictors of SVD disease. Duration of RLS was an independent predictor of the burden of cerebral SVD (area P < 0.00012 and volume P < 0.0025), whereas sex and insomnia were not. Conclusion: RLS duration should be taken into account when analyzing the association between RLS and cerebrovascular disease; our data support the hypothesis that a long-lasting RLS and its accompanying periodic limb movements in sleep are a risk factor for silent SVD and perhaps for the development of clinical stroke. Citation: Ferri R, Cosentino FI, Moussouttas M, Lanuzza B, Aricò D, Bagai K, Wang L, McLaughlin B, Walters AS. Silent cerebral small vessel disease in restless legs syndrome. SLEEP 2016;39(7):1371–1377. PMID:27091527

  13. Mood disorders in restless legs syndrome (Willis-Ekbom disease).

    PubMed

    Becker, Philip M; Sharon, Denise

    2014-07-01

    Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sensorimotor disorder that can result in considerable sleep disruption. This narrative review provides an overview of RLS diagnosis and reports epidemiologic evidence for an association between RLS and mood disorders. Possible links between RLS, sleep disturbances, and mood disorders are considered, and theoretical pathophysiologic pathways are discussed. Finally, pharmacologic therapies for RLS are summarized. A PubMed search was performed using the search term restless legs syndrome in combination with affective/anxiety, antidepressants, anxiety/anxiety disorder, attention deficit hyperactivity disorder, depression/depressive disorder, mood/mood disorder, neuropsychiatric, panic/panic disorder, psychiatric disorder, and psychosis. English-language articles published between January 1993 and May 2013 were retrieved. Additional studies were identified from the reference lists of relevant publications. 173 publications were retrieved. Articles related to the association between idiopathic RLS and depression, anxiety, and mood disorders were reviewed. In total, 32 epidemiologic studies were identified. These studies were reviewed in detail and ranked according to quality. Data were extracted on the basis of relevance to the topic. Epidemiologic studies were assessed using 3 parameters: methodology, data quality, and generalizability of the results. Each factor was scored from 1 (high quality) to 4 (low quality), giving a total score of between 3 and 12 for each study. RLS and mood disorders are frequently comorbid. Recognition and appropriate treatment of comorbid RLS are particularly important in patients with psychiatric disorders, as RLS is a common medical reason for insomnia, and antidepressant use may exacerbate sensory symptoms. © Copyright 2014 Physicians Postgraduate Press, Inc.

  14. Restless Legs Syndrome and Sleep-Wake Disturbances in Pregnancy.

    PubMed

    Dunietz, Galit Levi; Lisabeth, Lynda D; Shedden, Kerby; Shamim-Uzzaman, Q Afifa; Bullough, Alexandra S; Chames, Mark C; Bowden, Marc F; O'Brien, Louise M

    2017-07-15

    To estimate the association of restless legs syndrome (RLS) and its frequency with sleep-wake disturbances in pregnancy. A cohort of 1,563 women in their third trimester of pregnancy were recruited from prenatal clinics between March 2007 and December 2010. Demographic, pregnancy, and delivery data were extracted from medical records and sleep information was collected with questionnaires. To diagnose RLS, we used standardized criteria of RLS symptoms and frequency that were developed by the International Restless Legs Study Group. Logistic regression models were constructed to investigate the association of RLS and its frequency with sleep-wake disturbances (poor sleep quality, daytime sleepiness, poor daytime function) and delivery outcomes. Overall 36% of the pregnant women had RLS, and half had moderate to severe symptoms. Compared to women without RLS, those with RLS were more likely to have poor sleep quality (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.7-2.9), poor daytime function (OR 1.9, 95% CI 1.4-2.4), and excessive daytime sleepiness (OR 1.6, 95% CI 1.3-2.0). A dose-response relationship also was evident between RLS frequency and each of the sleep-wake disturbances. There was no evidence for any association between RLS and delivery outcomes. RLS is a significant contributor to poor sleep quality, daytime sleepiness, and poor daytime function, all common and often debilitating conditions in pregnancy. Obstetric health care providers should be aware of these associations and screen women for RLS. A commentary on this article appears in this issue on page 857.

  15. Restless leg syndrome in patients with spinal cord injury.

    PubMed

    Kumru, Hatice; Vidal, Joan; Benito, Jesus; Barrio, Manuela; Portell, Enric; Valles, Margarita; Flores, Cecilia; Santamaria, Joan

    2015-12-01

    The presence of restless leg syndrome (RLS) in patients with spinal cord injury (SCI) is not well established. We studied the frequency and severity of RLS in a population of patients with SCI and the effect of treatment with dopaminergic drugs when clinically indicated. Consecutive patients with SCI admitted to an out-patient clinic of a neurorehabilitation hospital (n:195) were evaluated for the presence of RLS between February 2013 and May 2014. A diagnosis of RLS was made according to the criteria of the International RLS Study Group, and severity was assessed by the RLS rating scale. Information on gender, age, time since SCI, level and severity of SCI, was obtained. The mean age was 54.7 ± 15.6 years (range: 22-81 year); with time since SCI: 16.9 ± 11.4 years (range: 1-50 years). Thirty-five of 195 patients (17.9%) presented RLS. Twenty-two out of 154 (14.3%) patients with cervicothoracic SCI and 13 out of 41 (31.7%) patients with lumbosacral SCI presented RLS. Restless leg symptoms were mild in 2 patients, moderate in 10 patients, severe in 12 patients and very severe in 11. Ten patients received dopaminergic agonist treatment with a significant reduction in RLS severity scale from 29.1 ± 5.9 to 10.2 ± 7.9. RLS occurs frequently in SCI patients and responds to dopaminergic treatment. Physicians have to be aware of this diagnosis to avoid unnecessary suffering in this patient population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Is restless legs syndrome associated with chronic mountain sickness?

    PubMed

    Vizcarra-Escobar, Darwin; Mendiola-Yamasato, Andrea; Risco-Rocca, Jorge; Mariños-Velarde, Alejandro; Juárez-Belaunde, Alan; Anculle-Arauco, Victor; Rivera-Chira, María

    2015-08-01

    Restless legs syndrome (RLS) and chronic mountain sickness (CMS) share physiological traits. Our objective was to explore a possible association between RLS and CMS. We carried a cross-sectional study with male subjects living between 4100 and 4300 m above sea level. Participants underwent a clinical interview, physical examination, electrocardiographic (EKG) recording, and spirometry. We classified subjects into CMS, Limbo, and healthy high-altitude dwellers (hHAD), according to their Quinghai score and hematocrit levels. We applied the "Paradigm of questions for epidemiological studies of RLS," The International Restless Leg Syndrome Study Group Scale, and the Pittsburgh Sleep Quality Index. Logistic regression analysis was used to determine the association between variables. Seventy-eight male subjects were included. Forty subjects were hHAD, 23 were CMS patients, and 15 participants were considered as Limbo. CMS and Limbo subjects had a higher frequency of RLS (p <0.05). Limbo subjects had the highest severity score for RLS. There were no differences in age, body mass index (BMI), or tobacco use between RLS patients and non-sufferers. In the multivariate analysis, CMS was not associated with RLS diagnosis. Oxygen saturation (p = 0.019), poor sleep quality (p <0.01), and Quinghai score of ≥6 (p = 0.026) were independently associated with RLS diagnosis. Our results did not show a direct association between RLS and CMS; however, RLS was associated with reduced oxygen saturation. Hence, RLS could represent an early clinical manifestation of hypoxia, or, in CMS natural history, an early sign of maladaptation to high altitude. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Restless Legs Syndrome: Current Concepts about Disease Pathophysiology

    PubMed Central

    Koo, Brian B.; Bagai, Kanika; Walters, Arthur S.

    2016-01-01

    Background In the past few decades, much has been learned about the pathophysiology of restless legs syndrome (RLS). Investigators have studied neuropathology, imaging, electrophysiology, and genetics of RLS, identifying brain regions and biological systems affected in RLS. This manuscript will review RLS pathophysiology literature, examining the RLS state through consideration of the neuroanatomy, then the biological, organ, and genetic systems. Methods Pubmed (1966 to April 2016) was searched for the term “restless legs syndrome” cross-referenced with “pathophysiology,” “pathogenesis,” “pathology,” or “imaging.” English language papers were reviewed. Studies that focused on RLS in relation to another disease were not reviewed. Results Although there are no gross structural brain abnormalities in RLS, widespread brain areas are activated, including the pre- and post-central gyri, cingulate cortex, thalamus, and cerebellum. Pathologically, the most consistent finding is striatal iron deficiency in RLS patients. A host of other biological systems are also altered in RLS, including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems. Polymorphisms in genes including BTBD9 and MEIS1 are associated with RLS. Discussion RLS is a neurologic sensorimotor disorder that involves pathology, most notably iron deficiency, in motor and sensory brain areas. Brain areas not subserving movement or sensation such as the cingulate cortex and cerebellum are also involved. Other biological systems including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems are involved. Further research is needed to determine which of these anatomic locations or biological systems are affected primarily, and which are affected in a secondary response. PMID:27536462

  18. Quiescence Correlates Strongly with Directly Measured Black Hole Mass in Central Galaxies

    NASA Astrophysics Data System (ADS)

    Terrazas, Bryan A.; Bell, Eric F.; Henriques, Bruno M. B.; White, Simon D. M.; Cattaneo, Andrea; Woo, Joanna

    2016-10-01

    Roughly half of all stars reside in galaxies without significant ongoing star formation. However, galaxy formation models indicate that it is energetically challenging to suppress the cooling of gas and the formation of stars in galaxies that lie at the centers of their dark matter halos. In this Letter, we show that the dependence of quiescence on black hole and stellar mass is a powerful discriminant between differing models for the mechanisms that suppress star formation. Using observations of 91 star-forming and quiescent central galaxies with directly measured black hole masses, we find that quiescent galaxies host more massive black holes than star-forming galaxies with similar stellar masses. This observational result is in qualitative agreement with models that assume that effective, more-or-less continuous active galactic nucleus feedback suppresses star formation, strongly suggesting the importance of the black hole in producing quiescence in central galaxies.

  19. The Hippo signalling pathway maintains quiescence in Drosophila neural stem cells

    PubMed Central

    Ding, Rouven; Weynans, Kevin; Bossing, Torsten; Barros, Claudia S.; Berger, Christian

    2016-01-01

    Stem cells control their mitotic activity to decide whether to proliferate or to stay in quiescence. Drosophila neural stem cells (NSCs) are quiescent at early larval stages, when they are reactivated in response to metabolic changes. Here we report that cell-contact inhibition of growth through the canonical Hippo signalling pathway maintains NSC quiescence. Loss of the core kinases hippo or warts leads to premature nuclear localization of the transcriptional co-activator Yorkie and initiation of growth and proliferation in NSCs. Yorkie is necessary and sufficient for NSC reactivation, growth and proliferation. The Hippo pathway activity is modulated via inter-cellular transmembrane proteins Crumbs and Echinoid that are both expressed in a nutrient-dependent way in niche glial cells and NSCs. Loss of crumbs or echinoid in the niche only is sufficient to reactivate NSCs. Finally, we provide evidence that the Hippo pathway activity discriminates quiescent from non-quiescent NSCs in the Drosophila nervous system. PMID:26821647

  20. Brain natriuretic peptide (BNP) produced by the human chorioamnion may mediate pregnancy myometrial quiescence.

    PubMed

    Carvajal, Jorge A; Delpiano, Ana M; Cuello, Mauricio A; Poblete, Jose A; Casanello, Paola C; Sobrevia, Luis A; Weiner, Carl P

    2009-01-01

    We aim to demonstrate that Brain Natriuretic Peptide (BNP) is synthesized and released from the fetal membranes and mediates pregnancy myometrial quiescence. Myometrium and fetal membranes (FM) were obtained from term and preterm pregnancies at the time of cesarean section, either in labor or not in labor. BNP was measured in term and preterm FM, in culture cells, and conditioned media. We found BNP (but not ANP or CNP) inhibited contractions of preterm, but not term, human myometrium. BNP (both protein and mRNA) was detected in all tissues, conditioned media and cultured cells. BNP was higher in samples from preterm women not in labor compared to those at term not in labor. BNP concentrations were significantly reduced in women in spontaneous preterm labor. We conclude that locally produced BNP may be involved in generating myometrial quiescence during pregnancy. Further, a premature decrease of BNP production may cause preterm labor.

  1. Msi RNA-binding proteins control reserve intestinal stem cell quiescence

    PubMed Central

    Yousefi, Maryam; Li, Ning; Jensen, Shane T.

    2016-01-01

    Regeneration of the intestinal epithelium is driven by multiple intestinal stem cell (ISC) types, including an active, radiosensitive Wnthigh ISC that fuels turnover during homeostasis and a reserve, radioresistant Wntlow/off ISC capable of generating active Wnthigh ISCs. We examined the role of the Msi family of oncoproteins in the ISC compartment. We demonstrated that Msi proteins are dispensable for normal homeostasis and self-renewal of the active ISC, despite their being highly expressed in these cells. In contrast, Msi proteins are required specifically for activation of reserve ISCs, where Msi activity is both necessary and sufficient to drive exit from quiescence and entry into the cell cycle. Ablation of Msi activity in reserve ISCs rendered the epithelium unable to regenerate in response to injury that ablates the active stem cell compartment. These findings delineate a molecular mechanism governing reserve ISC quiescence and demonstrate a necessity for the activity of this rare stem cell population in intestinal regeneration. PMID:27799368

  2. V729 Sgr: a long period dwarf nova showing negative superhumps during quiescence

    NASA Astrophysics Data System (ADS)

    Ramsay, Gavin; Wood, Matt A.; Cannizzo, John K.; Howell, Steve B.; Smale, Alan

    2017-07-01

    We report K2 observations of the eclipsing cataclysmic variable V729 Sgr which covered nearly 80 d in duration. We find five short outbursts and two long outbursts, one of which shows a clear plateau phase in the rise to maximum brightness. The mean time between successive short outbursts is ˜10 d while the time between the two long outbursts is ˜38 d. The frequency of these outbursts is unprecedented for a cataclysmic variable (CV) above the orbital period gap. We find evidence that the mid-point of the eclipse occurs systematically earlier in outburst than in quiescence. During five of the six quiescent epochs we find evidence for a second photometric period which is roughly 5 per cent shorter than the 4.16 h orbital period which we attribute to negative superhumps. V729 Sgr is therefore one of the longest period CVs to show negative superhumps during quiescence.

  3. The Hippo signalling pathway maintains quiescence in Drosophila neural stem cells.

    PubMed

    Ding, Rouven; Weynans, Kevin; Bossing, Torsten; Barros, Claudia S; Berger, Christian

    2016-01-29

    Stem cells control their mitotic activity to decide whether to proliferate or to stay in quiescence. Drosophila neural stem cells (NSCs) are quiescent at early larval stages, when they are reactivated in response to metabolic changes. Here we report that cell-contact inhibition of growth through the canonical Hippo signalling pathway maintains NSC quiescence. Loss of the core kinases hippo or warts leads to premature nuclear localization of the transcriptional co-activator Yorkie and initiation of growth and proliferation in NSCs. Yorkie is necessary and sufficient for NSC reactivation, growth and proliferation. The Hippo pathway activity is modulated via inter-cellular transmembrane proteins Crumbs and Echinoid that are both expressed in a nutrient-dependent way in niche glial cells and NSCs. Loss of crumbs or echinoid in the niche only is sufficient to reactivate NSCs. Finally, we provide evidence that the Hippo pathway activity discriminates quiescent from non-quiescent NSCs in the Drosophila nervous system.

  4. A stable microtubule array drives fission yeast polarity reestablishment upon quiescence exit

    PubMed Central

    Laporte, Damien; Courtout, Fabien; Pinson, Benoît; Dompierre, Jim; Salin, Bénédicte; Brocard, Lysiane

    2015-01-01

    Cells perpetually face the decision to proliferate or to stay quiescent. Here we show that upon quiescence establishment, Schizosaccharomyces pombe cells drastically rearrange both their actin and microtubule (MT) cytoskeletons and lose their polarity. Indeed, while polarity markers are lost from cell extremities, actin patches and cables are reorganized into actin bodies, which are stable actin filament–containing structures. Astonishingly, MTs are also stabilized and rearranged into a novel antiparallel bundle associated with the spindle pole body, named Q-MT bundle. We have identified proteins involved in this process and propose a molecular model for Q-MT bundle formation. Finally and importantly, we reveal that Q-MT bundle elongation is involved in polarity reestablishment upon quiescence exit and thereby the efficient return to the proliferative state. Our work demonstrates that quiescent S. pombe cells assemble specific cytoskeleton structures that improve the swiftness of the transition back to proliferation. PMID:26124291

  5. Precursory seismic quiescence along the Sumatra-Andaman subduction zone: past and present

    NASA Astrophysics Data System (ADS)

    Sukrungsri, Santawat; Pailoplee, Santi

    2016-07-01

    In this study, the seismic quiescence prior to hazardous earthquakes was analyzed along the Sumatra-Andaman subduction zone (SASZ). The seismicity data were screened statistically with mainshock earthquakes of M w ≥ 4.4 reported during 1980-2015 being defined as the completeness database. In order to examine the possibility of using the seismic quiescence stage as a marker of subsequent earthquakes, the seismicity data reported prior to the eight major earthquakes along the SASZ were analyzed for changes in their seismicity rate using the statistical Z test. Iterative tests revealed that Z factors of N = 50 events and T = 2 years were optimal for detecting sudden rate changes such as quiescence and to map these spatially. The observed quiescence periods conformed to the subsequent major earthquake occurrences both spatially and temporally. Using suitable conditions obtained from successive retrospective tests, the seismicity rate changes were then mapped from the most up-to-date seismicity data available. This revealed three areas along the SASZ that might generate a major earthquake in the future: (i) Nicobar Islands (Z = 6.7), (ii) the western offshore side of Sumatra Island (Z = 7.1), and (iii) western Myanmar (Z = 6.7). The performance of a stochastic test using a number of synthetic randomized catalogues indicated these levels of anomalous Z value showed the above anomaly is unlikely due to chance or random fluctuations of the earthquake. Thus, these three areas have a high possibility of generating a strong-to-major earthquake in the future.

  6. Precursory seismic quiescence along the Sumatra-Andaman subduction zone: past and present

    NASA Astrophysics Data System (ADS)

    Sukrungsri, Santawat; Pailoplee, Santi

    2017-03-01

    In this study, the seismic quiescence prior to hazardous earthquakes was analyzed along the Sumatra-Andaman subduction zone (SASZ). The seismicity data were screened statistically with mainshock earthquakes of M w ≥ 4.4 reported during 1980-2015 being defined as the completeness database. In order to examine the possibility of using the seismic quiescence stage as a marker of subsequent earthquakes, the seismicity data reported prior to the eight major earthquakes along the SASZ were analyzed for changes in their seismicity rate using the statistical Z test. Iterative tests revealed that Z factors of N = 50 events and T = 2 years were optimal for detecting sudden rate changes such as quiescence and to map these spatially. The observed quiescence periods conformed to the subsequent major earthquake occurrences both spatially and temporally. Using suitable conditions obtained from successive retrospective tests, the seismicity rate changes were then mapped from the most up-to-date seismicity data available. This revealed three areas along the SASZ that might generate a major earthquake in the future: (i) Nicobar Islands ( Z = 6.7), (ii) the western offshore side of Sumatra Island ( Z = 7.1), and (iii) western Myanmar ( Z = 6.7). The performance of a stochastic test using a number of synthetic randomized catalogues indicated these levels of anomalous Z value showed the above anomaly is unlikely due to chance or random fluctuations of the earthquake. Thus, these three areas have a high possibility of generating a strong-to-major earthquake in the future.

  7. Distinct histone methylation and transcription profiles are established during the development of cellular quiescence in yeast.

    PubMed

    Young, Conor P; Hillyer, Cory; Hokamp, Karsten; Fitzpatrick, Darren J; Konstantinov, Nikifor K; Welty, Jacqueline S; Ness, Scott A; Werner-Washburne, Margaret; Fleming, Alastair B; Osley, Mary Ann

    2017-01-26

    Quiescent cells have a low level of gene activity compared to growing cells. Using a yeast model for cellular quiescence, we defined the genome-wide profiles of three species of histone methylation associated with active transcription between growing and quiescent cells, and correlated these profiles with the presence of RNA polymerase II and transcripts. Quiescent cells retained histone methylations normally associated with transcriptionally active chromatin and had many transcripts in common with growing cells. Quiescent cells also contained significant levels of RNA polymerase II, but only low levels of the canonical initiating and elongating forms of the polymerase. The RNA polymerase II associated with genes in quiescent cells displayed a distinct occupancy profile compared to its pattern of occupancy across genes in actively growing cells. Although transcription is generally repressed in quiescent cells, analysis of individual genes identified a period of active transcription during the development of quiescence. The data suggest that the transcript profile and histone methylation marks in quiescent cells were established both in growing cells and during the development of quiescence and then retained in these cells. Together, this might ensure that quiescent cells can rapidly adapt to a changing environment to resume growth.

  8. A Genetic Screen for Saccharomyces cerevisiae Mutants That Fail to Enter Quiescence

    PubMed Central

    Li, Lihong; Miles, Shawna; Breeden, Linda L.

    2015-01-01

    Budding yeast begin the transition to quiescence by prolonging G1 and accumulating limited nutrients. They undergo asymmetric cell divisions, slow cellular expansion, acquire significant stress tolerance and construct elaborate cell walls. These morphologic changes give rise to quiescent (Q) cells, which can be distinguished from three other cell types in a stationary phase culture by flow cytometry. We have used flow cytometry to screen for genes that are required to obtain the quiescent cell fraction. We find that cell wall integrity is critical and these genes may help define quiescence-specific features of the cell wall. Genes required to evade the host innate immune response are common. These may be new targets for antifungal drugs. Acquired thermotolerance is also a common property, and we show that the stress-response transcription factors Msn2 and Msn4 promote quiescence. Many other pathways also contribute, including a subset of genes involved in autophagy, ubiquitin-mediated proteolysis, DNA replication, bud site selection, and cytokinesis. PMID:26068574

  9. A Genetic Screen for Saccharomyces cerevisiae Mutants That Fail to Enter Quiescence.

    PubMed

    Li, Lihong; Miles, Shawna; Breeden, Linda L

    2015-06-10

    Budding yeast begin the transition to quiescence by prolonging G1 and accumulating limited nutrients. They undergo asymmetric cell divisions, slow cellular expansion, acquire significant stress tolerance and construct elaborate cell walls. These morphologic changes give rise to quiescent (Q) cells, which can be distinguished from three other cell types in a stationary phase culture by flow cytometry. We have used flow cytometry to screen for genes that are required to obtain the quiescent cell fraction. We find that cell wall integrity is critical and these genes may help define quiescence-specific features of the cell wall. Genes required to evade the host innate immune response are common. These may be new targets for antifungal drugs. Acquired thermotolerance is also a common property, and we show that the stress-response transcription factors Msn2 and Msn4 promote quiescence. Many other pathways also contribute, including a subset of genes involved in autophagy, ubiquitin-mediated proteolysis, DNA replication, bud site selection, and cytokinesis.

  10. Transcriptional Control of Cell-Cycle Quiescence During C. elegans Development

    PubMed Central

    Clayton, Joseph E.; van den Heuvel, Sander J.L.; Saito, R. Mako

    2008-01-01

    During the development of the C. elegans reproductive system, cells that give rise to the vulva, the vulval precursor cells (VPCs), remain quiescent for two larval stages before resuming cell division in the third larval stage. We have identified several transcriptional regulators that contribute to this temporary cell-cycle arrest. Mutation of lin-1 or lin-31, two downstream targets of the Receptor Tyrosine kinase (RTK)/Ras/MAP kinase cascade that controls VPC cell fate, disrupts the temporary VPC quiescence. We found that the LIN-1/Ets and LIN-31/FoxB transcription factors promote expression of CKI-1, a member of the p27 family of cyclin-dependent kinase inhibitors (CKIs). LIN-1 and LIN-31 promote cki-1/Kip-1 transcription prior to their inhibition through RTK/Ras/MAPK activation. Another mutation identified in the screen defined the mdt-13 TRAP240 Mediator subunit. Further analysis of the multisubunit Mediator complex revealed that a specific subset of its components act in VPC quiescence. These components substantially overlap with the CDK-8 module implicated in transcriptional repression. Taken together, strict control of cell-cycle quiescence during VPC development involves transcriptional induction of CKI-1 and transcriptional regulation through the Mediator complex. These transcriptional regulators represent potential molecular connections between development and the basic cell-cycle machinery. PMID:18082681

  11. Do Quiescence and Wasp Venom-Induced Lethargy Share Common Neuronal Mechanisms in Cockroaches?

    PubMed Central

    2017-01-01

    The escape behavior of a cockroach may not occur when it is either in a quiescent state or after being stung by the jewel wasp (Ampulex compressa). In the present paper, we show that quiescence is an innate lethargic state during which the cockroach is less responsive to external stimuli. The neuronal mechanism of such a state is poorly understood. In contrast to quiescence, the venom-induced lethargic state is not an innate state in cockroaches. The Jewel Wasp disables the escape behavior of cockroaches by injecting its venom directly in the head ganglia, inside a neuropile called the central complex a ‘higher center’ known to regulate motor behaviors. In this paper we show that the coxal slow motoneuron ongoing activity, known to be involved in posture, is reduced in quiescent animals, as compared to awake animals, and it is further reduced in stung animals. Moreover, the regular tonic firing of the slow motoneuron present in both awake and quiescent cockroaches is lost in stung cockroaches. Injection of procaine to prevent neuronal activity into the central complex to mimic the wasp venom injection produces a similar effect on the activity of the slow motoneuron. In conclusion, we speculate that the neuronal modulation during the quiescence and venom-induced lethargic states may occur in the central complex and that both states could share a common neuronal mechanism. PMID:28045911

  12. The Dwarf Novae UZ Serpentis and SS Aurigae During Quiescence: Exposed White Dwarfs?

    NASA Astrophysics Data System (ADS)

    Lake, J.; Sion, E. M.

    2000-12-01

    UZ Serpentis and SS Aurigae are both U Geminorum-type dwarf novae with similar orbital periods, outburst amplitudes, and outburst recurrence times. Since dwarf novae above the period gap have higher accretion rates, their accretion disks may remain optically thick even during quiescence. Hence the detection of the white dwarf is more difficult. UZ Ser and SS Aur offer the possiblity of extending the range of systems for which the underlying white dwarf accreter has been analyzed with model atmospheres. We have applied the Massa-Fitzpatrick (2000) flux calibration correction to the archival IUE NEWSIPS SWP spectra of these two systems, obtained during dwarf nova quiescence. We have carried out high gravity model atmosphere using the codes TLUSTY195, SYNSPEC42, ROTIN and accretion disk synthetic spectra from the grid of Wade and Hubeny (1998). We have determined the physical properties of the white dwarf accreters, including temperature, gravity chemical abundances estimates, and the accretion rate during quiescence. We discuss our results in the context of the overall picture of accretion physics in dwarf novae and the effects of accretion on the white dwarf. This research was supported in part by NSF grant AST 99-01955, NASA ADP grant NAG5-8388 and by summer research funding from the NASA- Delaware Space Grant Colleges Consortium.

  13. The X-Ray Spectral Evolution of Galactic Black Hole X-Ray Binaries toward Quiescence

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard. M.; Gallo, Elena; Jonker, Peter G.

    2013-08-01

    Most transient black hole X-ray binaries (BHXBs) spend the bulk of their time in a quiescent state, where they accrete matter from their companion star at highly sub-Eddington luminosities (we define quiescence here as a normalized Eddington ratio lx = L 0.5-10 keV/L Edd < 10-5). Here, we present Chandra X-ray imaging spectroscopy for three BHXB systems (H 1743-322, MAXI J1659-152, and XTE J1752-223) as they fade into quiescence following an outburst. Multiple X-ray observations were taken within one month of each other, allowing us to track each individual system's X-ray spectral evolution during its decay. We compare these three systems to other BHXB systems. We confirm that quiescent BHXBs have softer X-ray spectra than low-hard-state BHXBs, and that quiescent BHXB spectral properties show no dependence on the binary system's orbital parameters. However, the observed anti-correlation between X-ray photon index (Γ) and lx in the low-hard state does not continue once a BHXB enters quiescence. Instead, Γ plateaus to an average langΓrang = 2.08 ± 0.07 by the time lx reaches ~10-5. lx ~ 10-5 is thus an observationally motivated upper limit for the beginning of the quiescent spectral state. Our results are discussed in the context of different accretion flow models and across the black hole mass scale.

  14. Laminin-111 and the Level of Nuclear Actin Regulate Epithelial Quiescence via Exportin-6.

    PubMed

    Fiore, Ana Paula Zen Petisco; Spencer, Virginia A; Mori, Hidetoshi; Carvalho, Hernandes F; Bissell, Mina J; Bruni-Cardoso, Alexandre

    2017-06-06

    Nuclear actin (N-actin) is known to participate in the regulation of gene expression. We showed previously that N-actin levels mediate the growth and quiescence of mouse epithelial cells in response to laminin-111 (LN1), a component of the mammary basement membrane (BM). We know that BM is defective in malignant cells, and we show here that it is the LN1/N-actin pathway that is aberrant in human breast cancer cells, leading to continuous growth. Photobleaching assays revealed that N-actin exit in nonmalignant cells begins as early as 30 min after LN1 treatment. LN1 attenuates the PI3K pathway leading to upregulation of exportin-6 (XPO6) activity and shuttles actin out of the nucleus. Silencing XPO6 prevents quiescence. Malignant cells are impervious to LN1 signaling. These results shed light on the crucial role of LN1 in quiescence and differentiation and how defects in the LN1/PI3K/XPO6/N-actin axis explain the loss of tissue homeostasis and growth control that contributes to malignant progression. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. Transcriptional quiescence of paternal mtDNA in cyprinid fish embryos

    PubMed Central

    Wen, Ming; Peng, Liangyue; Hu, Xinjiang; Zhao, Yuling; Liu, Shaojun; Hong, Yunhan

    2016-01-01

    Mitochondrial homoplasmy signifies the existence of identical copies of mitochondrial DNA (mtDNA) and is essential for normal development, as heteroplasmy causes abnormal development and diseases in human. Homoplasmy in many organisms is ensured by maternal mtDNA inheritance through either absence of paternal mtDNA delivery or early elimination of paternal mtDNA. However, whether paternal mtDNA is transcribed has remained unknown. Here we report that paternal mtDNA shows late elimination and transcriptional quiescence in cyprinid fishes. Paternal mtDNA was present in zygotes but absent in larvae and adult organs of goldfish and blunt-snout bream, demonstrating paternal mtDNA delivery and elimination for maternal mtDNA inheritance. Surprisingly, paternal mtDNA remained detectable up to the heartbeat stage, suggesting its late elimination leading to embryonic heteroplasmy up to advanced embryogenesis. Most importantly, we never detected the cytb RNA of paternal mtDNA at all stages when paternal mtDNA was easily detectable, which reveals that paternal mtDNA is transcriptionally quiescent and thus excludes its effect on the development of heteroplasmic embryos. Therefore, paternal mtDNA in cyprinids shows late elimination and transcriptional quiescence. Clearly, transcriptional quiescence of paternal mtDNA represents a new mechanism for maternal mtDNA inheritance and provides implications for treating mitochondrion-associated diseases by mitochondrial transfer or replacement. PMID:27334806

  16. Vitamin A and insulin are required for the maintenance of hepatic stellate cell quiescence.

    PubMed

    Yoneda, Akihiro; Sakai-Sawada, Kaori; Niitsu, Yoshiro; Tamura, Yasuaki

    2016-02-01

    Transdifferentiation of vitamin A-storing hepatic stellate cells (HSCs) to vitamin A-depleted myofibroblastic cells leads to liver fibrosis. Vitamin A regulates lipid accumulation and gene transcription, suggesting that vitamin A is involved in the maintenance of HSC quiescence under a physiological condition. However, the precise mechanism remains elusive because there is no appropriate in vitro culture system for quiescent HSCs. Here, we show that treatment of quiescent HSCs with vitamin A partially maintained the accumulation of lipid droplets and expression of quiescent HSC markers (glial fibrillary acidic protein, peroxisome proliferator-activator receptor-γ and CCAAT/enhancer-binding protein-α) and also the expression of myofibroblastic markers (α-smooth muscle actin, heat shock protein 47 and collagen type I). On the other hand, combined treatment with vitamin A and insulin sustained the characteristic of HSC quiescence and completely suppressed the expression of myofibroblastic markers through activation of the JAK2/STAT5 signaling pathway and increased expression of sterol regulatory element binding protein-1. These treated HSCs transdifferentiated to myofibroblastic cells under a culture condition with fetal bovine serum. The results suggest an important role of vitamin A and insulin in the maintenance of HSC quiescence under a physiological condition. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Do Quiescence and Wasp Venom-Induced Lethargy Share Common Neuronal Mechanisms in Cockroaches?

    PubMed

    Emanuel, Stav; Libersat, Frederic

    2017-01-01

    The escape behavior of a cockroach may not occur when it is either in a quiescent state or after being stung by the jewel wasp (Ampulex compressa). In the present paper, we show that quiescence is an innate lethargic state during which the cockroach is less responsive to external stimuli. The neuronal mechanism of such a state is poorly understood. In contrast to quiescence, the venom-induced lethargic state is not an innate state in cockroaches. The Jewel Wasp disables the escape behavior of cockroaches by injecting its venom directly in the head ganglia, inside a neuropile called the central complex a 'higher center' known to regulate motor behaviors. In this paper we show that the coxal slow motoneuron ongoing activity, known to be involved in posture, is reduced in quiescent animals, as compared to awake animals, and it is further reduced in stung animals. Moreover, the regular tonic firing of the slow motoneuron present in both awake and quiescent cockroaches is lost in stung cockroaches. Injection of procaine to prevent neuronal activity into the central complex to mimic the wasp venom injection produces a similar effect on the activity of the slow motoneuron. In conclusion, we speculate that the neuronal modulation during the quiescence and venom-induced lethargic states may occur in the central complex and that both states could share a common neuronal mechanism.

  18. Thermonuclear Processes as a Principal Source of the Earth's Internal Energy

    NASA Astrophysics Data System (ADS)

    Terez, E. I.; Terez, I. E.

    2011-12-01

    A cosmological model of the formation of the Solar System is presented. It is shown that the main source of the Earth's energy is delivered from the thermonuclear processes in the inner Earth's core consisting of metallic hydrides. Several theoretical studies showed that under low temperature (T<104 K) and sufficiently high density of plasma, the characteristics of nuclear synthesis could be explained only with some adjustments to a thermonuclear synthesis theory. By building a diagram of the mass luminosity for the giant planets and the Earth, Wang Hong-Zhang (1990) illustrated that this diagram was similar to the one corresponding to stars. This could have only one explanation-the energy is due to the thermonuclear reactions and the energy rate is increasing exponentially with temperature and pressure. In the local areas where thermonuclear reactions occur in the Earth core, one should expect a sharp increase in temperature which causes of the dissolution of hydrides, e.g. release of hydrogen from the hydride-ionic form to the proton gas in large quantities (Larin, 2005). The pressure in this zone would sharply rise, and this would cause expulsion of the streams of the hydrogen plasma outside of the Earth's core. As a result of the Earth rotation and existence of the Coriolis' acceleration, the hydrogen plumes (more exactly, the proton gas) characterized by a high electrical conductivity twirl in spirals in the outer core of the Earth. These spirals form solenoid and, as a result, create the dipole magnetic field of the Earth. The suggest hypothesis of the thermonuclear nature of the Earth's energy flux is a main reason for the endogenic geodynamic and tectonic processes in the Earth's history. This hypothesis is supported by known experimental facts, and it opens new ways to study not only our planet but other planets of the Solar System. One should note that according to accepted concepts, the dipole magnetic field could exist in planets with a sufficient

  19. Impact of restless legs syndrome in patients with inflammatory bowel disease on sleep, fatigue, and quality of life.

    PubMed

    Schindlbeck, Katharina A; Becker, Janek; Berger, Felix; Mehl, Arne; Rewitzer, Charlotte; Geffe, Sarah; Koch, Peter M; Preiß, Jan C; Siegmund, Britta; Maul, Jochen; Marzinzik, Frank

    2017-01-01

    Inflammatory bowel disease has been associated with neurological symptoms including restless legs syndrome. Here, we investigated the impact of restless legs syndrome in patients with inflammatory bowel disease on sleep, fatigue, mood, cognition, and quality of life. Two groups of inflammatory bowel disease patients, with and without restless legs syndrome, were prospectively evaluated for sleep disorders, fatigue, daytime sleepiness, depression, anxiety, and health-related quality of life. Furthermore, global cognitive function, executive function, attention, and concentration were assessed in both groups. Disease activity and duration of inflammatory bowel disease as well as current medication were assessed by interview. Inflammatory bowel disease patients with and without restless legs syndrome were matched for age, education, severity, and duration of their inflammatory bowel disease. Patients with inflammatory bowel disease and clinically relevant restless leg syndrome suffered significantly more frequent from sleep disturbances including sleep latency and duration, more fatigue, and worse health-related quality of life as compared to inflammatory bowel disease patients without restless legs syndrome. Affect and cognitive function including cognitive flexibility, attention, and concentration showed no significant differences among groups, indicating to be not related to restless legs syndrome. Sleep disorders including longer sleep latency, shorter sleep duration, and fatigue are characteristic symptoms of restless legs syndrome in inflammatory bowel disease patients, resulting in worse health-related quality of life. Therefore, clinicians treating patients with inflammatory bowel disease should be alert for restless legs syndrome.

  20. Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

    PubMed Central

    Pereira, José Carlos; da Silva Neto, João Luiz Pereira; Pradella-Hallinan, Márcia

    2011-01-01

    OBJECTIVE: There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery. METHOD: A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject. RESULTS: In our cohort, 7 males (23%) and 30 females (39%) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83%) had restless legs after the knee surgery- exclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69%) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31%) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test. CONCLUSION: Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system. PMID:22086528

  1. Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery.

    PubMed

    Pereira, José Carlos; Silva Neto, João Luiz Pereira da; Pradella-Hallinan, Márcia

    2011-01-01

    There are no data adressing the prevalence of restless legs syndrome in subjects who have knee prosthesis. Therefore, we conducted a cross-sectional survey of subjects who underwent knee prosthesis surgery. A total of 107 subjects (30 male, 77 female) were interviewed over the telephone regarding restless legs syndrome symptoms. If the patients exhibited symptoms of the syndrome, we conducted face-to-face interviews. Lastly, a therapeutic test with pramipexole was proposed for each subject. In our cohort, 7 males (23%) and 30 females (39%) had restless legs syndrome. Of these, 6 males and 23 females were submitted to face-to-face-interview. Of the males, 5 (83%) had restless legs after the knee surgery-exclusively in the operated leg- and reported no family restless legs history. One man had a prior case of bilateral restless legs syndrome, a positive family history and claimed exacerbation of symptoms in the operated leg. Among the females, 16 (69%) had restless legs prior to surgery. A total of 10 female patients reported bilateral symptoms, with fewer symptoms in the operated leg, while 6 displayed a worse outcome in the operated leg. The 7 females (31%) without restless legs prior to surgery and without a family history experienced symptoms only in the operated leg. All subjects responded favorably to the pramipexole therapeutic test. Our results suggest that secondary unilateral restless legs syndrome may ensue from knee prosthesis surgery and that the symptoms are generated in the peripheral nervous system.

  2. The optical counterparts of accreting millisecond X-ray pulsars during quiescence

    NASA Astrophysics Data System (ADS)

    D'Avanzo, P.; Campana, S.; Casares, J.; Covino, S.; Israel, G. L.; Stella, L.

    2009-12-01

    Context: Eight accreting millisecond X-ray pulsars (AMXPs) are known to date. Although these systems are well studied at high energies, very little information is available for their optical/NIR counterparts. Up to now, only two of them, SAX J1808.4-3658 and IGR J00291+5934, have a secure multi-band detection of their optical counterparts in quiescence. Aims: All these systems are transient low-mass X-ray binaries. Optical and NIR observations carried out during quiescence give a unique opportunity to constrain the nature of the donor star and to investigate the origin of the observed quiescent luminosity at long wavelengths. In addition, optical observations can be fundamental as they ultimately allow us to estimate the compact object mass through mass function measurements. Methods: Using data obtained with the ESO-Very Large Telescope, we performed a deep optical and NIR photometric study of the fields of XTE J1814-338 and of the ultracompact systems XTE J0929-314 and XTE J1807-294 during quiescence in order to look for the presence of a variable counterpart. If suitable candidates were found, we also carried out optical spectroscopy. Results: We present here the first multi-band (VR) detection of the optical counterpart of XTE J1814-338 in quiescence together with its optical spectrum. The optical light curve shows variability in both bands consistent with a sinusoidal modulation at the known 4.3 h orbital period and presents a puzzling decrease of the V-band flux around superior conjunction that may be interpreted as a partial eclipse. The marginal detection of the very faint counterpart of XTE J0929-314 and deep upper limits for the optical/NIR counterpart of XTE J1807-294 are also reported. We also briefly discuss the results reported in the literature for the optical/NIR counterpart of XTE J1751-305. Conclusions: Our findings are consistent with AMXPs being systems containing an old, weakly magnetized neutron star, reactivated as a millisecond radio pulsar

  3. Alternative approaches to the design of targets for a hybrid thermonuclear station

    SciTech Connect

    Basov, N G; Lebo, I G; Rozanov, Vladislav B; Feoktistov, L P; Tishkin, V F

    1998-04-30

    Targets with low degrees of compression, such as those with internal energy deposition, two-stage conical targets for lasers emitting pulses of duration of the order of 100 ns, and multilayer shell targets for short-pulse long-wavelength CO{sub 2} and CO lasers may prove acceptable for hybrid thermonuclear reactors with high values (of the order of 10{sup 3}) of the gain in the blanket. Estimates and one-dimensional calculations of the compression of such targets are reported for the laser radiation energy range 0.2-2 MJ. (interaction of laser radiation with matter. laser plasma)

  4. Fermi-GBM detection of a thermonuclear burst from 4U 1608-52

    NASA Astrophysics Data System (ADS)

    Jenke, P.; Linares, M.; Connaughton, V.; van der Horst, A. J.; Camero-Arranz, A.; Finger, M.; Wilson-Hodge, C.; Kouveliotou, C.

    2012-05-01

    We report the detection with Fermi-GBM (daily CTIME data, 12-25 keV band) of an X-ray burst from a location consistent with the neutron star low-mass X-ray binary and thermonuclear burster 4U 1608-52. The burst peak occurred on May 2, 2012 at 06:47:54 UTC. The Fermi-GBM location of the burst is R.A.(J2000) = 241.3 deg, DEC(J2000) = -51.1 deg (1.8 deg from 4U 1608-52) with a 1 sigma error of 4.7 deg.

  5. Association between irritable bowel syndrome and restless legs syndrome in the general population.

    PubMed

    Yun, Chang-Ho; Lee, Seung K; Kim, Hyun; Park, Hee-Kwon; Lee, Seung H; Kim, Se J; Shin, Chol

    2012-10-01

    This study aimed to explore the association between restless legs syndrome and irritable bowel syndrome in an epidemiological cohort. We included 3365 adults, of whom 1602 were female (age 52.5 ± 7.5 years), who had participated in the Korean Genome and Epidemiology Study (2005-2006). The diagnosis of restless legs syndrome was based on the criteria proposed by the International Restless Legs Syndrome Study Group, and irritable bowel syndrome was defined according to the Rome II criteria. The prevalence of each condition was determined and their association was tested by logistic regression analysis. Age, sex, haemoglobin concentration, renal insufficiency, use of medications and depressive mood were all adjusted for. The prevalence of restless legs syndrome and irritable bowel syndrome was 4.5 and 11.1%, respectively. Irritable bowel syndrome was more prevalent in the group with restless legs syndrome (24.0 versus 10.5%, P < 0.001). Subjects with restless legs syndrome were older (54.2 ± 8.4 versus 52.4 ± 7.4, P = 0.006) and more depressive (26.7 versus 12.5%, P < 0.001), and were predominantly female (57.3 versus 47.2%, P = 0.015), had more frequent insomnia symptoms (44.0 versus 28.2%, P < 0.001), had lower haemoglobin concentration (13.7 ± 1.5 versus 14.1 ± 1.6 g dL(-1) P = 0.004) and higher highly sensitive C-reactive protein (1.8 ± 5.1 versus 1.4 ± 2.9 mg dL(-1), P = 0.08). The adjusted odds ratio of restless legs syndrome in relation to irritable bowel syndrome was 2.59 (1.74-3.85, P < 0.001). Irritable bowel syndrome appeared to be associated with restless legs syndrome independently from other major risk factors for restless legs syndrome. Searching for the mechanisms underlying this association is indicated.

  6. FROM THE HISTORY OF PHYSICS: The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 — the first Soviet two-stage thermonuclear charge)

    NASA Astrophysics Data System (ADS)

    Goncharov, German A.

    2005-11-01

    On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country.

  7. A prospective case control questionnaire study for restless leg syndrome on 600 pregnant women.

    PubMed

    Ozer, İrfan; Guzel, Işıl; Orhan, Gürdal; Erkılınç, Selçuk; Öztekin, Neşe; Ak, Fikri; Taşçı, Yasemin

    2017-04-21

    To evaluate the clinical characteristics of pregnant women with restless leg syndrome (RLS). A total of 600 pregnant women were asked to complete a questionnaire of RLS and medications. The educational and socio-economical status was significantly lower in study group. The number of patients living in joint family in the study group was statistically higher compared to control group. Hypothyroidism was more frequent in the study group. Calcium and magnesium intake were significantly higher in patients with RLS inversely iron intake was higher in patients without RLS. Lower hemoglobin levels were found to increase the risk of restless leg in pregnancy. Living in a joint family and low educational status were also independent risk factors for restless leg in pregnancy. Iron intake was found to decrease the risk of restless leg. Lower hemoglobin levels were found to be discriminative factor for the presence of RLS. Severity of RLS decreased by iron intake and increased by magnesium intake. Hemoglobin levels, iron intake, living in joint family, educational status are the independent risk factors for restless leg in pregnancy. Lower hemoglobin levels and supplementation of iron are the independent predictors for severity of RLS in pregnant women.

  8. Migratory restlessness in captive individuals predicts actual departure in the wild.

    PubMed

    Eikenaar, Cas; Klinner, Thomas; Szostek, K Lesley; Bairlein, Franz

    2014-01-01

    In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such 'migratory restlessness' has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific traits. These studies thus assumed that, also at the level of the individual, migratory restlessness is an accurate proxy for the motivation to migrate. We tested this assumption for the first time and found that it holds; individuals showing very little migratory restlessness remained at stopover for longer than one night, whereas most individuals showing more restlessness departed sooner. This finding validates the use of migratory restlessness as a proxy for the motivation to migrate, thereby justifying the conclusions made in a large body of research on avian migration.

  9. The Effect of Stretching Exercises on Severity of Restless Legs Syndrome in Patients on Hemodialysis

    PubMed Central

    Aliasgharpour, Mansooreh; Abbasi, Zahra; Pedram Razi, Shadan; Kazemnezhad, Anoshiravan

    2016-01-01

    Background The restless legs syndrome is a sensorimotor disorder that is very common in patients on hemodialysis. Due to pharmacological treatments which have their own side effects, nowadays, studies have turned to non-pharmacological treatments. Objectives The present study aims to assess the effect of stretching exercises on the severity of restless legs syndrome in patients on hemodialysis. Patients and Methods This clinical trial study was conducted on 33 patients who had been identified using diagnostic criteria from the hemodialysis ward of Hasheminejad Hospital in Tehran. Participants were randomly divided into the intervention group (n = 17) and control group (n = 16). Stretching exercises were performed on legs during the dialysis for half an hour, three times a week for 8 weeks in intervention group. Data were collected by using the international restless legs syndrome study group scale. Results The results showed that the majority of participants were suffering from moderate restless legs syndrome. The symptom severity of this syndrome meaningfully changed eight weeks after intervention in the intervention group compared to the control group (P < 0.001). Conclusions The results highlighted the significance of training and performing the stretching exercises during dialysis for the purpose of improving restless legs syndrome symptoms and the quality of care of hemodialysis patients. PMID:27625757

  10. The Effect of Stretching Exercises on Severity of Restless Legs Syndrome in Patients on Hemodialysis.

    PubMed

    Aliasgharpour, Mansooreh; Abbasi, Zahra; Pedram Razi, Shadan; Kazemnezhad, Anoshiravan

    2016-06-01

    The restless legs syndrome is a sensorimotor disorder that is very common in patients on hemodialysis. Due to pharmacological treatments which have their own side effects, nowadays, studies have turned to non-pharmacological treatments. The present study aims to assess the effect of stretching exercises on the severity of restless legs syndrome in patients on hemodialysis. This clinical trial study was conducted on 33 patients who had been identified using diagnostic criteria from the hemodialysis ward of Hasheminejad Hospital in Tehran. Participants were randomly divided into the intervention group (n = 17) and control group (n = 16). Stretching exercises were performed on legs during the dialysis for half an hour, three times a week for 8 weeks in intervention group. Data were collected by using the international restless legs syndrome study group scale. The results showed that the majority of participants were suffering from moderate restless legs syndrome. The symptom severity of this syndrome meaningfully changed eight weeks after intervention in the intervention group compared to the control group (P < 0.001). The results highlighted the significance of training and performing the stretching exercises during dialysis for the purpose of improving restless legs syndrome symptoms and the quality of care of hemodialysis patients.

  11. Restless Leg Syndrome and Sleep Quality in Lumbar Radiculopathy Patients

    PubMed Central

    Terzi, Murat; Akpinar, Kursad; Paksoy, Kemal; Cebeci, Ibrahim; Iyigun, Omer

    2014-01-01

    Background. To investigate the frequency of restless leg syndrome (RLS), sleep quality impairment, depression, fatigue, and sleep behavior disorder and to determine the effects of surgery on these parameters in radiculopathy patients resistant to conservative treatment. Methods. The present study included 66 lumbar radiculopathy patients, who were resistant to conservative treatment and had indication of surgery. Five different questionnaires were performed to assess depression (the Beck Depression Inventory (BDI)), sleep quality (the Pittsburgh Sleep Quality Index (PSQI)), fatigue (the Fatigue Severity Scale (FSS)), and presence of RLS and rapid eye movement sleep behavior disorder (RBD). The same questionnaires were also performed on a control group (n = 61). Results. Of the radiculopathy patients, 68.1% had RLS and 92.4% had fatigue. Of the controls, 16.4% had RLS and 59% had fatigue. RBD was present in 8 (12.1%) patients and 3 (4.9%) controls. The PSQI revealed that sleep quality was impaired in 46 (69.7%) patients and 35 (57.4%) controls (P > 0.05). The number of individuals having substantial depression according to the BDI was significantly higher in the patients than in the controls. Conclusions. There was a significant increase in the frequency of RLS, which was significantly decreased in the postoperative period in the radiculopathy patients. PMID:25110396

  12. Predictive factors of restless leg syndrome in hemodialysis patients.

    PubMed

    Eftekhari, Adel; Nasiriani, Khadijeh; Mirzaei, Samaneh; Azimpour Ardakani, Somayeh

    2016-01-01

    The restless leg syndrome (RLS) is a neurologic disorder suffering the hemodialysis patients. Although the pathophysiology of this syndrome remains unknown yet, an investigation of the parameters pertinent to it may help to develop the related medical knowledge and to improve the therapeutic-care interventions in this regard. The correlation between the RLSs on individual, clinical, and laboratory indices in patients undergoing hemodialysis. This descriptive-analytic study was conducted on 104 hemodialysis patients. Diagnosis of RLS was made using the International RLS Standard Questionnaire. The data on individual, clinical, and laboratory indices were obtained from patients' recorded files and interviews. Based on our findings, 28.8% of the patients undergoing hemodialysis were affected with mild RLS, 41.7% with moderate RLS, and 29.5% with severe RLS. There was a statistically significant correlation between affliction with RLS on the one hand, and age and gender, on the other (P < 0.05). However, there was no significant correlation between RLS and education level, occupation, length of hemodialysis, fasting blood sugar (FBS), hepatitis B and C, serum blood urea nitrogen (BUN), creatinine (Cr), iron, hemoglobin (Hb) level and also KT/Vor URR (P < 0.05). Regarding the high prevalence of RLS among the hemodialysis patients, there is the necessity for taking more care of these patients to reduce the somatic complications of the RLS especially among the elderly and female patients and to control the blood sugar of these patients at the normal level.

  13. Restless leg syndrome and sleep quality in lumbar radiculopathy patients.

    PubMed

    Kocabicak, Ersoy; Terzi, Murat; Akpinar, Kursad; Paksoy, Kemal; Cebeci, Ibrahim; Iyigun, Omer

    2014-01-01

    To investigate the frequency of restless leg syndrome (RLS), sleep quality impairment, depression, fatigue, and sleep behavior disorder and to determine the effects of surgery on these parameters in radiculopathy patients resistant to conservative treatment. The present study included 66 lumbar radiculopathy patients, who were resistant to conservative treatment and had indication of surgery. Five different questionnaires were performed to assess depression (the Beck Depression Inventory (BDI)), sleep quality (the Pittsburgh Sleep Quality Index (PSQI)), fatigue (the Fatigue Severity Scale (FSS)), and presence of RLS and rapid eye movement sleep behavior disorder (RBD). The same questionnaires were also performed on a control group (n = 61). Of the radiculopathy patients, 68.1% had RLS and 92.4% had fatigue. Of the controls, 16.4% had RLS and 59% had fatigue. RBD was present in 8 (12.1%) patients and 3 (4.9%) controls. The PSQI revealed that sleep quality was impaired in 46 (69.7%) patients and 35 (57.4%) controls (P > 0.05). The number of individuals having substantial depression according to the BDI was significantly higher in the patients than in the controls. There was a significant increase in the frequency of RLS, which was significantly decreased in the postoperative period in the radiculopathy patients.

  14. Apomorphine in idiopathic restless legs syndrome: an exploratory study

    PubMed Central

    Tribl, G; Sycha, T; Kotzailias, N; Zeitlhofer, J; Auff, E

    2005-01-01

    Background: Dopaminergic and opioidergic drugs have been found to be effective in patients with restless legs syndrome (RLS). Objectives: To test the effect of apomorphine—a combined opioidergic and dopaminergic agonist—and subsequent selective antagonism by naloxone and metoclopramide on subjective and objective symptoms in patients with idiopathic RLS. Methods: Nine patients with RLS were pretreated with oral domperidone for three days. A modified suggested immobilisation test (SIT) was carried out between 8 pm and 1 am under the following conditions of intravenous drug administration: baseline–apomorphine–apomorphine plus naloxone–apomorphine plus metoclopramide. Outcome variables were a visual analogue scale (VAS) of subjective RLS symptoms and EMG documented periodic leg movements while awake (PLMW). Results: Compared with baseline, apomorphine resulted in a rapid and significant improvement in subjective RLS symptoms as measured by VAS (54.5% improvement; p = 0.011), and an almost immediate cessation of PLMW, measured by PLMW index (98.0% improvement; p = 0.012). Neither additional naloxone nor metoclopramide blocked this effect significantly. While given apomorphine with metoclopramide, there was a trend to reappearance of PLMW. Conclusions: Apomorphine may be an effective treatment for idiopathic RLS. Its effectiveness may reflect both to its dopaminergic and its opioidergic activity, and is not diminished significantly by blocking only one of these pathways. The trend to a worsening of the PLMW index with metoclopramide hints at a primarily dopaminergic effect of apomorphine in idiopathic RLS. PMID:15654028

  15. Restless Legs Syndrome, pica, and iron status in blood donors

    PubMed Central

    Spencer, Bryan R.; Kleinman, Steven; Wright, David J.; Glynn, Simone A.; Rye, David B.; Kiss, Joseph E.; Mast, Alan E.; Cable, Ritchard G.

    2014-01-01

    BACKGROUND The association of blood donation related iron deficiency with pica or Restless Leg Syndrome (RLS) remains poorly elucidated. This study evaluated the prevalence of RLS and pica in blood donors completing the REDS-II Iron Status Evaluation (RISE) Study. STUDY DESIGN AND METHODS RISE enrolled 2425 blood donors in a prospective cohort study; 1334 donors provided blood samples to characterize iron status and answered a questionnaire inquiring into symptoms of RLS and pica at a final visit after 15–24 months of follow-up. Associations between both conditions and iron status were evaluated. RESULTS There were 9% and 20% of donors reporting symptoms of Probable or Probable/Possible RLS, respectively. Iron depletion and donation intensity were not predictive of RLS. Pica was reported by 65 donors (5.5%), half of whom reported daily cravings. Prevalence of pica increased with degree of iron depletion in women (2% in iron replete females, 13% in those with ferritin < 12ng/mL), but not in men. Probable RLS and pica co-expressed in 8 individuals, but no more frequently than expected by chance. CONCLUSION RLS and pica have been associated with iron deficiency in non-donor populations. This study indicates a potentially high prevalence of RLS in frequent blood donors but shows no association with iron status or donation intensity. Low iron stores were associated with higher prevalence of pica, but only in females. Furthermore, the results are incompatible with RLS and pica sharing a common pathophysiology. PMID:23763445

  16. Ropinirole for the treatment of restless legs syndrome

    PubMed Central

    Kushida, Clete A

    2006-01-01

    Dopaminergic agents, anticonvulsants, benzodiazepines, opiates, and iron supplementation comprise the classes of medications commonly used to treat restless legs syndrome (RLS), which is a disorder that is estimated to affect about 1 in 10 individuals worldwide and impacts an affected patient’s sleep, mood, daytime function, and quality of life. RLS is characterized by an urge to move the legs that is worse at bedtime and at rest; the symptoms are temporarily relieved by leg movement. It is frequently accompanied by periodic limb movements during sleep (PLMS), which may independently disrupt sleep and may cause daytime drowsiness. Dopaminergic agents are considered to be first-line therapy in the management of RLS as well as PLMS. Ropinirole (Requip®, GlaxoSmithKline) is a dopamine agonist that was the first medication approved by the US Food and Drug Administration (FDA) for the treatment of moderate-to-severe primary RLS. Based on several large-scale clinical trials and open-label clinical series, this medication has been demonstrated to be effective and safe in treating the motor symptoms of RLS and improving sleep quality. PMID:19412490

  17. Peripheral hypoxia in restless legs syndrome (Willis-Ekbom disease).

    PubMed

    Salminen, Aaro V; Rimpilä, Ville; Polo, Olli

    2014-05-27

    A case-control study to measure oxygen and carbon dioxide partial pressures in the legs in order to assess the involvement of peripheral hypoxia or hypercapnia in the pathogenesis of restless legs syndrome (RLS). RLS severity was assessed with a standard questionnaire. Suggested immobilization tests were performed twice in 15 patients with RLS and 14 healthy controls. Patients with RLS participated in the tests with and without pramipexole medication. During the tests, peripheral oxygen and carbon dioxide partial pressures were measured noninvasively on the skin of the legs and the chest. During immobilization, the patients with RLS had lower partial pressure of oxygen in their legs (5.54 vs 7.19 kPa, p < 0.01) but not on the chest (8.75 vs 8.20 kPa, p = 0.355). More severe RLS correlated with high chest-to-foot oxygen gradient (ρ = 0.692, p < 0.01). Carbon dioxide levels did not differ between the groups. Pramipexole corrected the peripheral hypoxia toward the levels observed in the controls (from 5.54 to 6.65 kPa, p < 0.05). Peripheral hypoxia is associated with the appearance of RLS symptoms. Strong correlation with RLS severity suggests a close pathophysiologic link between peripheral hypoxia and the symptoms of RLS. This is further supported by the simultaneous reversal of hypoxia and discomfort by dopaminergic treatment. © 2014 American Academy of Neurology.

  18. Restless Legs Syndrome in Patients With Chronic Kidney Disease.

    PubMed

    Novak, Marta; Winkelman, John W; Unruh, Mark

    2015-07-01

    Symptoms of restless legs syndrome (RLS) are common in patients with chronic kidney disease (CKD) on dialysis; symptoms of RLS are estimated to affect up to 25% of patients on dialysis when the international RLS diagnostic criteria are applied. RLS is a neurologic disorder with a circadian rhythmicity characterized by an overwhelming urge to move the legs during rest, which can be relieved temporarily by movement. RLS has been associated with an increase in sleep disturbance, higher cardiovascular morbidity, decreased quality of life, and an increased risk of death in patients with CKD. Although the exact pathophysiology of RLS is unknown, it is thought to involve an imbalance in iron metabolism and dopamine neurotransmission in the brain. The symptoms of moderate to severe RLS can be treated with several pharmacologic agents; however, data specific to patients on dialysis with RLS are lacking. The purpose of this article is to examine the relationship between, and complications of, RLS and CKD both in dialysis and nondialysis patients, and discuss the treatment options for patients on dialysis with RLS. Copyright © 2015. Published by Elsevier Inc.

  19. [Update on the treatment of restless legs syndrome].

    PubMed

    Konno, Michiko; Uchiyama, Makoto

    2009-05-01

    Restless legs syndrome (RLS) is a sensorimotor disorder characterized by an irresistible urge to move the legs, accompanied by uncomfortable and unpleasant sensations that diminish with motor activity and worsen at rest. The symptoms of this syndrome worsen in the evening and at night, leading to difficulty in sleeping. Treatment of RLS includes non-pharmacological intervention and drug therapy. In this article, we examine recent developments in the understanding of the pathophysiology of RLS and review previous articles on the treatment of RLS. Although there have been no reports on formal studies on the nonpharmacologic strategies for RLS symptoms, recommened good sleep hygiene is considered essential to improve the comorbid insomnia. Massaging the affected legs, taking hot baths, and performing mentally demanding tasks have been reported to reduce RLS symptoms. Four categories of medications, namely, dopaminergic agents, opioids, anticonvulsants, and benzodiazepines were identified as frequently prescribed drugs for RLS. Dopaminergic agonists are now considered the first-line treatment of RLS because they are more effective and produce augmentation less frequently as compared to L-dopa. Opioids are prescribed to patients with severe conditions, especially those unresponsive to other treatments. Currently, carbamazepine is not recommended for the treatment of RLS. More recently, studies on the use of anticonvulsants for the treatment of RLS have focused on gabapentin. Benzodiazepines, including clonazepam and nitrazepam, are widely prescribed, but their therapeutic effects on RLS symptoms were rather modest. Therefore, benzodiazepines are mostly used to improve the sleep quality in patients with RLS.

  20. Electrophysiological findings of Turkish patients with restless legs syndrome.

    PubMed

    Özsimsek, Ahmet; Koyuncuoglu, Hasan Rifat

    2017-01-01

    We aimed to investigate changes in electrophysiological findings in Turkish patients with restless legs syndrome (RLS), including F-wave latency (FWL), peripheral silent period (PSP), and Hoffmann reflex. The study took place in a university hospital in Turkey and involved 30 newly diagnosed RLS patients and 30 healthy controls who were matched for age and gender. Participant's demographics (age, gender, weight, and height), laboratory findings, and electrophysiological test outcomes were gathered and analyzed. There was no significant difference in the FWL of the median and ulnar nerves, whereas the H-wave maximum amplitude and H/M ratio were significantly higher in the RLS patients than in the controls at rest. All of the PSP parameters were similar between patients and controls for the abductor pollicis brevis and gastrocnemius muscles. However, for the tibialis anterior muscle, all the PSP duration parameters were shorter in the RLS patients, whereas the PSP latency parameters were similar. The data suggest that there may be a reduction in spinal segmental inhibition at the L4-L5-S1 level, but the mechanisms of inhibition at the L4-L5 and S1 levels may be different; furthermore, there may be no pathology in the peripheral nerves. Further prospective studies with larger cohorts are now needed to evaluate the pathophysiology of RLS with different neurophysiological assessment tools.

  1. Restless leg syndrome: is it a real problem?

    PubMed Central

    Cotter, Paul E; O’Keeffe, Shaun T

    2006-01-01

    Restless legs syndrome (RLS) is a common condition that is frequently unrecognized, misdiagnosed and poorly managed. It is characterized by uncomfortable sensations deep in the legs developing at rest that compel the person to move; symptoms are worst at night and sleep disturbance is common. RLS occurs in 7%–11% of the population in Western countries, and many such people experience troublesome symptoms. Primary RLS is familial in up to two thirds of patients. RLS may also be secondary to a number of conditions including iron deficiency, pregnancy and end-stage renal failure and, perhaps, neuropathy. Secondary RLS is most common in those presenting for the first time in later life. The pathogenesis of RLS probably involves the interplay of systemic or brain iron deficiency and impaired dopaminergic neurotransmission in the subcortex of the brain. RLS is very responsive to dopaminergic therapies. Rebound of RLS symptoms during the early morning and development of severe symptoms earlier in the day (augmentation) are problematic in those treated for a prolonged period with levodopa. Consequently, dopamine agonists have become first line treatment. Anti-convulsant medications and opioids are helpful in some patients. Correction of underlying problem wherever possible is important in the management of secondary RLS. PMID:18360657

  2. Investigational approaches to therapies for restless legs syndrome.

    PubMed

    de Biase, Stefano; Merlino, Giovanni; Lorenzut, Simone; Valente, Mariarosaria; Gigli, Gian Luigi

    2014-06-01

    Restless Legs Syndrome (RLS) is a common neurological disorder that impairs nocturnal rest, causing decreased alertness, depressed mood, reduced job performance and poor quality of life. In patients affected by severe RLS, pharmacological treatment is mandatory. The present review is based on an extensive Internet and PubMed search from 1994 - 2014. It focuses on drugs currently in development for the treatment of RLS. The drugs currently available for treating RLS do not always allow the patient to obtain a dose capable of controlling the symptoms, particularly in the long term. There is still the need for effective and well-tolerated new drugs. Monoamine oxidase B inhibitors could be good candidates for the initial treatment of RLS, sparing stronger dopaminergic agents for later stages of the disease. Oxycodone-naloxone has demonstrated a significant and sustained effect on patients with severe RLS inadequately controlled with first-line drugs; it could be used as a long-term treatment option in severe cases of RLS for which alternative satisfactory drug regimens are unavailable. There is a paucity of data comparing medications in head-to-head trials to determine their relative effectiveness and adverse event profiles. Furthermore, there is also a need for further studies that evaluate nondopaminergic agonists and combination therapies for treating RLS.

  3. Sensory symptoms in restless legs syndrome: the enigma of pain.

    PubMed

    Winkelman, John W; Gagnon, Alison; Clair, Andrew G

    2013-10-01

    Restless legs syndrome (RLS) is a common sensorimotor condition characterized by an urge to move the legs, worsening of symptoms at rest and during the evening/night, and improvement of symptoms with movement. Our review explores the role and impact of sensory symptoms in RLS. The phenomenology of RLS is discussed, highlighting the difficulty patients have in describing their sensations and in differentiating between sensory and motor symptoms. Sensory symptoms have a significant impact on quality of life but remain much less well understood than motor symptoms and sleep disturbances in RLS. Although RLS symptoms usually are not described as painful, sensory manifestations in RLS do share some similarities with chronic pain sensations, and RLS frequently occurs in chronic pain and neuropathic conditions. Peripheral neuropathies may account for some of the sensory disturbances in secondary RLS, while alterations in central somatosensory processing may be a more viable explanation for the sensory disturbances in primary RLS. The effectiveness of analgesics in treating RLS supports the concept of abnormal sensory modulation in RLS and suggests an overlap between pain modulatory pathways and sensory disturbances. Future studies are needed to better understand the experiential and biologic aspects of altered sensory experiences in RLS. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Restless leg syndrome in diabetics compared with normal controls.

    PubMed

    Zobeiri, Mehdi; Shokoohi, Azita

    2014-01-01

    Introduction. Restless leg syndrome (RLS) is a common sleep disorder which is characterized by urge to move the legs accompanied by disturbing and uncomfortable leg sensation during night and rest. This common condition affects 7-10% of general population and is frequently unrecognized, misdiagnosed, and poorly managed. Several clinical conditions like diabetes have been associated with secondary form of RLS. This study analyzed the frequency and possible risk factor for RLS development in diabetic patient. Material and Methods. This descriptive case-control study was done on 140 consecutive outpatient diabetics and age, sex, and body mass index matched control group. RLS was diagnosed by criteria of the International RLS Study Group. Results. Prevalence of RLS was 28.6% in diabetes and 7.1% in control group (P = 0.001). Sex difference was not significant and with rising duration of diabetes prevalence of RLS was not increased. Discussion. With regarding significant association between RLS and diabetes and its negative impact on quality of life/health outcome/sleep/daytime activity/cognitive function/ and mental state of diabetic patient/higher awareness of RLS among physicians and related health worker suggested.

  5. Recognition, diagnosis, and treatment of restless legs syndrome.

    PubMed

    Smith, Jennifer E; Tolson, Jerry M

    2008-08-01

    To review the symptoms, diagnosis, and treatment of restless legs syndrome (RLS) and its relevance to nurse practitioners (NPs). Comprehensive review of the scientific literature on the diagnosis and treatment of RLS in adults. RLS is a chronic neurological disorder that, with varying degrees of severity, affects 5%-10% of the general population. Because of the circadian pattern of onset, the symptoms of RLS may be associated with significant sleep disturbance and may have a negative impact on quality of life. RLS is characterized by a compelling urge to move the legs and usually accompanied or caused by uncomfortable sensations in the legs. Symptoms begin or worsen during periods of rest or inactivity and are worse in the evening or at night. Other features supportive of a diagnosis include a family history, the presence of periodic leg movements in sleep, and the relief of symptoms after treatment with a dopaminergic therapy. Although the etiology of RLS is unknown, it is thought that symptoms result from a central dopaminergic dysfunction and dopamine agonists are considered first-line treatment for moderate-to-severe primary RLS. Nondopaminergic therapies and nonpharmacologic interventions may also be appropriate in the management of less severe cases of RLS. NPs are often the first healthcare providers to see patients with RLS and therefore need to be able to accurately recognize and diagnose the disorder; this, in turn, will enable them to successfully manage the treatment of RLS.

  6. Restless legs syndrome: pathophysiology, clinical presentation and management.

    PubMed

    Trenkwalder, Claudia; Paulus, Walter

    2010-06-01

    Restless legs syndrome (RLS) is a somatosensory network disorder that is clinically diagnosed according to four main criteria: an urge to move the legs, usually associated with unpleasant leg sensations; induction or exacerbation of symptoms by rest; symptom relief on activity; and diurnal fluctuations in symptoms with worsening in the evening and at night. Genetic variants in four chromosomal regions have been identified that increase the risk of RLS. In addition, various different lesions, ranging from peripheral neuropathies to spinal cord lesions or alterations of brain metabolism, are implicated in RLS. In most cases, sleep disorders with frequent sleep fragmentation and characteristic periodic limb movements during sleep can be identified during a polysomnographic recording. The first-line drugs for RLS are dopaminergic agents, which are effective in low to moderate doses. Alternative or additional treatments include opioids and anticonvulsants. Augmentation-paradoxical worsening of symptoms by dopaminergic treatment-is the main problem encountered in difficult-to-treat patients. Iron deficiency must be identified and treated by supplementation, both to improve RLS symptoms and to potentially lower the risk of augmentation. Here, we review the latest studies pertaining to the pathophysiology, clinical presentation and management of RLS.

  7. [Dopamine dysregulation syndrome in Parkinson's disease and restless legs syndrome].

    PubMed

    Bayard, Sophie; Cochen De Cock, Valérie; Dauvillers, Yves

    2011-06-01

    Dopamine replacement therapy in Parkinson's disease (PD) improves the motor symptoms. However, it has recently been shown that a small sub-group of patients suffers from motor and behavioral disturbances associated with the use of dopamine agonists (DAs). The behavioral disorders are incentive- or reward-based repetitive symptoms regrouped under the term « dopamine dysregulation syndrome » (DDS). They include pathological gambling, hypersexuality, compulsive shopping, compulsive eating, punding, and compulsive medication use. Whether these behaviors are related to the dopaminergic medications interacting with an underlying individual vulnerability or whether the primary pathological features of Parkinson's disease play a role is not entirely understood. This review is devoted to the phenomenology of the DDS and factors influencing its susceptibility. We further review the literature studies that investigated the decision-making profile using the Iowa Gambling Task in Parkinson's disease, and the recent literature devoted to these abnormal behaviors in the restless legs syndrome (RLS). Given the potential substantial impact of the DDS on personal, familial, social, and financial well-being, patients with PD or RLS should be informed that DAs use may lead to the development of impulsive and compulsive disorders, and clinicians should include the investigation of these disorders as part of routine clinical care. The refinement of clinical strategies to predict, identify and manage DDS will help the future care of motor and non-motor symptoms of Parkinson's disease.

  8. Heredity of restless legs syndrome in a pregnant population.

    PubMed

    Hennessy, Mary Dawn; De La Torre, Frances Aimee

    2013-01-01

    To synthesize published research on genetic and heredity findings related to restless legs syndrome (RLS) in a pregnant population. PubMed, CINAHL, and PsycINFO databases and reference lists from published articles. Literature searches were conducted for primary research studies published in English on the genetic and heredity findings of RLS in pregnant populations. Study characteristics and findings related to genetic and heredity aspects of RLS in a pregnant population. Five data-based articles met the criteria for study inclusion. Study findings comprised Level-2 and Level-3 evidence. Four of the five studies were larger population studies and contained a subset of pregnant participants. Parity and family history were important predictors of RLS proband status. Probands reported symptoms were often initiated during or after pregnancy. Symptoms of RLS for female probands are often initiated during pregnancy or after childbirth. A history of RLS in a previous pregnancy and family history of RLS were strong predictors of RLS in the current pregnancy. Future research on genetic associations of RLS in pregnancy is warranted. © 2013 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  9. Restless Legs Syndrome: From Pathophysiology to Clinical Diagnosis and Management

    PubMed Central

    Guo, Shiyi; Huang, Jinsha; Jiang, Haiyang; Han, Chao; Li, Jie; Xu, Xiaoyun; Zhang, Guoxin; Lin, Zhicheng; Xiong, Nian; Wang, Tao

    2017-01-01

    Restless legs syndrome (RLS), a common neurological sensorimotor disorder in western countries, has gained more and more attention in Asian countries. The prevalence of RLS is higher in older people and females. RLS is most commonly related to iron deficiency, pregnancy and uremia. The RLS symptoms show a significant circadian rhythm and a close relationship to periodic limb movements (PLMs) in clinical observations, while the pathophysiological pathways are still unknown. The diagnostic criteria have been revised in 2012 to improve the validity of RLS diagnosis. Recent studies have suggested an important role of iron decrease of brain in RLS pathophysiology. Dopaminergic (DA) system dysfunction in A11 cell groups has been recognized long ago from clinical treatment and autopsy. Nowadays, it is believed that iron dysfunction can affect DA system from different pathways and opioids have a protective effect on DA system. Several susceptible single nucleotide polymorphisms such as BTBD9 and MEIS1, which are thought to be involved in embryonic neuronal development, have been reported to be associated with RLS. Several pharmacological and non-pharmacological treatment are discussed in this review. First-line treatments of RLS include DA agents and α2δ agonists. Augmentation is very common in long-term treatment of RLS which makes prevention and management of augmentation very important for RLS patients. A combination of different types of medication is effective in preventing and treating augmentation. The knowledge on RLS is still limited, the pathophysiology and better management of RLS remain to be discovered. PMID:28626420

  10. Epidemiology of Restless Legs Syndrome: A Synthesis of the Literature

    PubMed Central

    Ohayon, Maurice M.; O'Hara, Ruth; Vitiello, Michael V.

    2011-01-01

    Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: (1) a symptom only, (2) a set of symptoms meeting minimal diagnostic criteria of the IRLSSG, (3) meeting minimal criteria accompanied with a specific frequency and/or severity, and (4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS. PMID:21795081

  11. Augmentation in restless legs syndrome patients in Korea.

    PubMed

    Jeon, Ji-Ye; Moon, Hye-Jin; Song, Mei Ling; Lee, Hochang B; Cho, Yong Won

    2015-05-01

    Augmentation has been known as the major complication of long-term dopaminergic treatment of restless legs syndrome (RLS). However, there have been no reports on the prevalence of augmentation in Korea. Thus, we aimed to assess the rate of augmentation and evaluate related factors in Korean RLS patients. Ninety-four idiopathic RLS patients who have been treated over a period of at least 6 months were enrolled. Thirty subjects were treated with a dopamine agonist only, and 64 were treated with a dopamine agonist and alpha two delta ligands. We assessed the clinical characteristics of those RLS subjects and evaluated the rate of augmentation. Augmentation was assessed using the NIH criteria for augmentation by two RLS experts independently. Eleven subjects (11.7%) were classified as having definitive or highly suggestive clinical indication of augmentation. In comparing the augmentation group with the non-augmentation group, there were no significant differences of baseline clinical characteristics. Four (13.3%) of the dopamine agonists monotherapy group and seven (10.9%) of the combination therapy group were categorized as augmentation. There was no significant difference in the augmentation rate between these two groups. We found an 11.7% augmentation rate in Korean RLS subjects. There was no difference in the rate of RLS augmentation between the dopaminergic monotherapy group and the combined treatment group. It may be related with using a similar dosage of dopaminergic drugs.

  12. THE X-RAY SPECTRAL EVOLUTION OF GALACTIC BLACK HOLE X-RAY BINARIES TOWARD QUIESCENCE

    SciTech Connect

    Plotkin, Richard M.; Gallo, Elena; Jonker, Peter G.

    2013-08-10

    Most transient black hole X-ray binaries (BHXBs) spend the bulk of their time in a quiescent state, where they accrete matter from their companion star at highly sub-Eddington luminosities (we define quiescence here as a normalized Eddington ratio l{sub x} = L{sub 0.5-10{sub keV}}/L{sub Edd} < 10{sup -5}). Here, we present Chandra X-ray imaging spectroscopy for three BHXB systems (H 1743-322, MAXI J1659-152, and XTE J1752-223) as they fade into quiescence following an outburst. Multiple X-ray observations were taken within one month of each other, allowing us to track each individual system's X-ray spectral evolution during its decay. We compare these three systems to other BHXB systems. We confirm that quiescent BHXBs have softer X-ray spectra than low-hard-state BHXBs, and that quiescent BHXB spectral properties show no dependence on the binary system's orbital parameters. However, the observed anti-correlation between X-ray photon index ({Gamma}) and l{sub x} in the low-hard state does not continue once a BHXB enters quiescence. Instead, {Gamma} plateaus to an average ({Gamma}) = 2.08 {+-} 0.07 by the time l{sub x} reaches {approx}10{sup -5}. l{sub x} {approx} 10{sup -5} is thus an observationally motivated upper limit for the beginning of the quiescent spectral state. Our results are discussed in the context of different accretion flow models and across the black hole mass scale.

  13. The Historical X-ray Transient KY TrA in quiescence

    NASA Astrophysics Data System (ADS)

    Zurita, C.; Corral-Santana, J. M.; Casares, J.

    2015-12-01

    We present deep optical images of the historical X-ray Transient KY TrA in quiescence from which we confirm the identification of the counterpart reported by Murdin et al. and derive an improved position of α = 15:28:16.97 and δ = -61:52:57.8. In 2007 June we obtained I, R and V images, where the counterpart seems to be double indicating the presence of an interloper at ˜1.4 arcsec NW. After separating the contribution of KY TrA we calculate I = 21.47 ± 0.09, R = 22.3 ± 0.1 and V = 23.6 ± 0.1. Similar brightness in the I-band was measured in 2004 May and 2010 June. Variability was analysed from series of images taken in 2004, spanning 0.6 h, and in two blocks of 6 h during 2007. We find that the target is not variable in any data set above the error levels ˜0.07 mags. The presence of the interloper might explain the non-detection of the classic ellipsoidal modulation; our data indicates that it contributes around half of the total flux, which would make a variation <0.15 mag not detectable. A single spectrum obtained in 2004 May shows the H α emission characteristic of X-ray transients in quiescence with a full width at half-maximum FWHM = 2700 ± 280 km s-1. If the system follows the FWHM-K2 correlation found by Casares, this would correspond to a velocity semi-amplitude of the donor star of K2 = 630 ± 74 km s-1. Based on the outburst amplitude and colours of the optical counterpart in quiescence we derive a crude estimate of the orbital period of 8 h and an upper limit of 15 h which would lead to mass function estimates of ≈9 M⊙ and <16 M⊙, respectively.

  14. Quiescence of human muscle stem cells is favored by culture on natural biopolymeric films.

    PubMed

    Monge, Claire; DiStasio, Nicholas; Rossi, Thomas; Sébastien, Muriel; Sakai, Hiroshi; Kalman, Benoit; Boudou, Thomas; Tajbakhsh, Shahragim; Marty, Isabelle; Bigot, Anne; Mouly, Vincent; Picart, Catherine

    2017-05-02

    Satellite cells are quiescent resident muscle stem cells that present an important potential to regenerate damaged tissue. However, this potential is diminished once they are removed from their niche environment in vivo, prohibiting the long-term study and genetic investigation of these cells. This study therefore aimed to provide a novel biomaterial platform for the in-vitro culture of human satellite cells that maintains their stem-like quiescent state, an important step for cell therapeutic studies. Human muscle satellite cells were isolated from two donors and cultured on soft biopolymeric films of controlled stiffness. Cell adhesive phenotype, maintenance of satellite cell quiescence and capacity for gene manipulation were investigated using FACS, western blotting, fluorescence microscopy and electron microscopy. About 85% of satellite cells cultured in vitro on soft biopolymer films for 3 days maintained expression of the quiescence marker Pax7, as compared with 60% on stiffer films and 50% on tissue culture plastic. The soft biopolymeric films allowed satellite cell culture for up to 6 days without renewing the media. These cells retained their stem-like properties, as evidenced by the expression of stem cell markers and reduced expression of differentiated markers. In addition, 95% of cells grown on these soft biopolymeric films were in the G0/G1 stage of the cell cycle, as opposed to those grown on plastic that became activated and began to proliferate and differentiate. Our study identifies a new biomaterial made of a biopolymer thin film for the maintenance of the quiescence state of muscle satellite cells. These cells could be activated at any point simply by replating them onto a plastic culture dish. Furthermore, these cells could be genetically manipulated by viral transduction, showing that this biomaterial may be further used for therapeutic strategies.

  15. Sumoylation is tumor-suppressive and confers proliferative quiescence to hematopoietic progenitors in Drosophila melanogaster larvae.

    PubMed

    Kalamarz, Marta E; Paddibhatla, Indira; Nadar, Christina; Govind, Shubha

    2012-03-15

    How cell-intrinsic regulation of the cell cycle and the extrinsic influence of the niche converge to provide proliferative quiescence, safeguard tissue integrity, and provide avenues to stop stem cells from giving rise to tumors is a major challenge in gene therapy and tissue engineering. We explore this question in sumoylation-deficient mutants of Drosophila. In wild type third instar larval lymph glands, a group of hematopoietic stem/progenitor cells acquires quiescence; a multicellular niche supports their undifferentiated state. However, how proliferative quiescence is instilled in this population is not understood. We show that Ubc9 protein is nuclear in this population. Loss of the SUMO-activating E1 enzyme, Aos1/Uba2, the conjugating E2 enzyme, Ubc9, or the E3 SUMO ligase, PIAS, results in a failure of progenitors to quiesce; progenitors become hyperplastic, misdifferentiate, and develop into microtumors that eventually detach from the dorsal vessel. Significantly, dysplasia and lethality of Ubc9 mutants are rescued when Ubc9(wt) is provided specifically in the progenitor populations, but not when it is provided in the niche or in the differentiated cortex. While normal progenitors express high levels of the Drosophila cyclin-dependent kinase inhibitor p21 homolog, Dacapo, the corresponding overgrown mutant population exhibits a marked reduction in Dacapo. Forced expression of either Dacapo or human p21 in progenitors shrinks this population. The selective expression of either protein in mutant progenitor cells, but not in other hematopoietic populations, limits overgrowth, blocks tumorogenesis, and restores organ integrity. We discuss an essential and complex role for sumoylation in preserving the hematopoietic progenitor states for stress response and in the context of normal development of the fly.

  16. Sumoylation is tumor-suppressive and confers proliferative quiescence to hematopoietic progenitors in Drosophila melanogaster larvae

    PubMed Central

    Kalamarz, Marta E.; Paddibhatla, Indira; Nadar, Christina; Govind, Shubha

    2012-01-01

    Summary How cell-intrinsic regulation of the cell cycle and the extrinsic influence of the niche converge to provide proliferative quiescence, safeguard tissue integrity, and provide avenues to stop stem cells from giving rise to tumors is a major challenge in gene therapy and tissue engineering. We explore this question in sumoylation-deficient mutants of Drosophila. In wild type third instar larval lymph glands, a group of hematopoietic stem/progenitor cells acquires quiescence; a multicellular niche supports their undifferentiated state. However, how proliferative quiescence is instilled in this population is not understood. We show that Ubc9 protein is nuclear in this population. Loss of the SUMO-activating E1 enzyme, Aos1/Uba2, the conjugating E2 enzyme, Ubc9, or the E3 SUMO ligase, PIAS, results in a failure of progenitors to quiesce; progenitors become hyperplastic, misdifferentiate, and develop into microtumors that eventually detach from the dorsal vessel. Significantly, dysplasia and lethality of Ubc9 mutants are rescued when Ubc9wt is provided specifically in the progenitor populations, but not when it is provided in the niche or in the differentiated cortex. While normal progenitors express high levels of the Drosophila cyclin-dependent kinase inhibitor p21 homolog, Dacapo, the corresponding overgrown mutant population exhibits a marked reduction in Dacapo. Forced expression of either Dacapo or human p21 in progenitors shrinks this population. The selective expression of either protein in mutant progenitor cells, but not in other hematopoietic populations, limits overgrowth, blocks tumorogenesis, and restores organ integrity. We discuss an essential and complex role for sumoylation in preserving the hematopoietic progenitor states for stress response and in the context of normal development of the fly. PMID:23213407

  17. Rearrangements of DNA-protein interactions in animal cells coupled with cellular growth-quiescence transitions.

    PubMed Central

    Lichtenstein, A V; Sjakste, N I; Zaboykin, M M; Shapot, V S

    1982-01-01

    Overall DNA-protein interactions in animal cells undergo drastic changes coupled with cellular transitions from quiescence to growth and reversely as revealed by nucleoprotein-Celite chromatography. DNA of chromatin was found to exist in one of the two sharply distinct alternative forms, namely, either tightly or weakly bound to protein moiety. These forms are specific for cycling and quiescent cells, respectively. The tight DNA-protein interactions characterize all cycling cells independent of the cell cycle phase. Transition of DNA of cycling cells from one form to another was observed as a result of treatment of isolated nuclei with DNase I. PMID:7063419

  18. Water stress can induce quiescence in newly-germinated onion (Allium cepa L.) seedlings.

    PubMed

    Whalley, W R; Lipiec, J; Finch-Savage, W E; Cope, R E; Clark, L J; Rowse, H R

    2001-05-01

    The effect of water stress on the early seedling growth of onions was studied by placing newly-germinated seedlings in vermiculite equilibrated at different water potentials. Roots and shoots elongated more at -0.29 than at -0.64 MPa, but did not elongate at -1.66 MPa. However, roots and shoots of seedlings that had been incubated in vermiculite at -1.66 MPa for up to 35 d resumed elongation when subsequently placed on wet filter boards. This suggests that water stress can induce quiescence in newly-germinated seedlings.

  19. Viscous evolution of accretion discs in the quiescence of dwarf novae

    NASA Technical Reports Server (NTRS)

    Mineshige, Shin; Wood, Janet H.

    1989-01-01

    Viscous evolution of accretion disks in the quiescence of dwarf novae is investigated semi-analytically. There are two key factors: the inward flow of the initial mass in the disk and the diffusion of the material added into the disk. The results are compared with the brightness temperature distributions obtained by the eclipse mapping of Z Cha and OY Car. The functional form of the viscosity parameter a, its values, the types of outbursts, and the application to soft X-ray transients are discussed.

  20. A theoretical integration of Cambrian explosion and post-Permian quiescence.

    PubMed

    Takahara, Y; Ono, N

    1997-01-01

    Trophic dynamics is internally causative. Each trophic level is causative in initiating changes in trophic flow either as a supplier towards the upper level or as a consumer towards the lower. Resource presentation followed by its subsequent exploitation makes suppliers causative, while resource exploitation followed by its subsequent presentation makes consumers causative. Trophic dynamics of supplier domination gradually alternates with that of consumer domination while being punctuated by occasional mass extinctions due to depletion of the resources towards the lowest trophic level. The Cambrian explosion could be associated with trophic dynamics of supplier domination, whereas the post-Permian quiescence with that of consumer influencing supplier domination.

  1. On the helical instability and efficient stagnation pressure production in thermonuclear magnetized inertial fusion

    NASA Astrophysics Data System (ADS)

    Sefkow, A. B.

    2016-10-01

    Magneto-inertial fusion experiments produce thermonuclear neutrons from plasma compressed to high convergence via z-pinch. Fusion fuel contained within a cylindrical metal liner is premagnetized with an axial field and laser-preheated prior to the liner's implosion by the JxB force. Convergence greater than 40 is inferred from x-ray self-emission spectroscopy and backlit x-ray radiography. The unprecedented stability is enabled by helical modes induced in the magnetized liner, the cause of which will be discussed, because of the suppression of the ubiquitous m=0 modes of the magneto-Rayleigh-Taylor instability found in many z-pinch implosions. The plasma temperature and flux are compressed to several keV and 100 MG at stagnation, enough to magnetically trap alpha particles and provide ``bootstrap'' self-heating when scaled to larger fusion yields with DT fuel. We present quantitative comparison between experimental observables and 3D modeling in support of the interpretation that this approach to laboratory fusion can scale to larger thermonuclear yields. Namely, the implosions efficiently convert liner kinetic energy to stagnated fuel internal energy with the expected pressures of 1 Gbar and burn durations of 2 ns, in agreement with both 2D and 3D modeling. Therefore, the analysis indicates the magnetized hot-spot dynamics are not dominated by implosion instability or residual kinetic energy in our best-performing experiments, wherein laser-induced non-fuel mix into the forming hot spot is low.

  2. Stabilization of burn conditions in a thermonuclear reactor using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Vitela, Javier E.; Martinell, Julio J.

    1998-02-01

    In this work we develop an artificial neural network (ANN) for the feedback stabilization of a thermonuclear reactor at nearly ignited burn conditions. A volume-averaged zero-dimensional nonlinear model is used to represent the time evolution of the electron density, the relative density of alpha particles and the temperature of the plasma, where a particular scaling law for the energy confinement time previously used by other authors, was adopted. The control actions include the concurrent modulation of the D-T refuelling rate, the injection of a neutral He-4 beam and an auxiliary heating power modulation, which are constrained to take values within a maximum and minimum levels. For this purpose a feedforward multilayer artificial neural network with sigmoidal activation function is trained using a back-propagation through-time technique. Numerical examples are used to illustrate the behaviour of the resulting ANN-dynamical system configuration. It is concluded that the resulting ANN can successfully stabilize the nonlinear model of the thermonuclear reactor at nearly ignited conditions for temperature and density departures significantly far from their nominal operating values. The NN-dynamical system configuration is shown to be robust with respect to the thermalization time of the alpha particles for perturbations within the region used to train the NN.

  3. Reevaluation of thermonuclear reaction rate of 50Fe(p, 𝜸)51Co

    NASA Astrophysics Data System (ADS)

    Zhang, Li-Ping; He, Jian-Jun; Chai, Wan-Dong; Hou, Su-Qing; Zhang, Li-Yong

    2016-11-01

    The thermonuclear rate of the 50Fe(p, 𝜸)51Co reaction in the Type I X-ray bursts (XRBs) temperature range has been reevaluated based on a recent precise mass measurement at CSRe Lanzhou, where the proton separation energy Sp = 142±77 keV has been determined firstly for the 51Co nucleus. Comparing to the previous theoretical predictions, the experimental Sp value has much smaller uncertainty. Based on the nuclear shell model and mirror nuclear structure information, we have calculated two sets of thermonuclear rates for the 50Fe(p, 𝜸)51Co reaction by utilizing the experimental Sp value. It shows that the statistical-model calculations are not ideally applicable for this reaction primarily because of the low density of low-lying excited states in 51Co. In this work, we recommend that a set of new reaction rates based on the mirror structure of 51Cr should be incorporated in future astrophysical network calculations. Supported by Natural Science Foundation of Inner Mongolia Autonomous Region of China (2013MS0916) and National Natural Science Foundation of China (11490562, 11405228)

  4. Analysis of Tokamak Fusion Test Reactor (TFTR) Prototype of International Thermonuclear Experimental Reactor (ITER)‡

    NASA Astrophysics Data System (ADS)

    Hester, Tim; Maglich, Bogdan; Scott, Dan; Calsec Collaboration

    2015-11-01

    TFTR produced world record of 10 million watts of controlled fusion power1 (CFP-1994) was summarized in Review1. We present evidence3 that: (1) TFTR input vs. output was 40 to 10 MW i.e. a power loss. (2) Review claims no experimental evidence for thermonuclear CFP production (only a calculation). (3) Ultra-high vacuum (UHV) required for τE = 0.2 s is 10-9 torr. TFTR had no UHV pumps, resulting in 10-3 torr, restricting τE <10-6 s, << thermalization time; 0.1 s., hence DT plasma did not occur. (4) Carbon ions were presented as D-T plasma. (5) Unknown neutron detector on unexplained neutron diamagnetic effect, measured ``fusion neutron power'' without particle energy identification, energy or coincidence. (6) 8 of 9 parameters claimed were inferred not measured. Quadratic test of TFTR data results2 in zero thermonuclear fusion power contribution to 10 MW: SFP = (0 +/- 1)%. ‡ Submitted to Physics of Plasmas†

  5. Thermonuclear .Ia Supernovae from Helium Shell Detonations: Explosion Models and Observables

    NASA Astrophysics Data System (ADS)

    Shen, Ken J.; Kasen, Dan; Weinberg, Nevin N.; Bildsten, Lars; Scannapieco, Evan

    2010-06-01

    During the early evolution of an AM Canum Venaticorum system, helium is accreted onto the surface of a white dwarf under conditions suitable for unstable thermonuclear ignition. The turbulent motions induced by the convective burning phase in the He envelope become strong enough to influence the propagation of burning fronts and may result in the onset of a detonation. Such an outcome would yield radioactive isotopes and a faint rapidly rising thermonuclear ".Ia" supernova. In this paper, we present hydrodynamic explosion models and observable outcomes of these He shell detonations for a range of initial core and envelope masses. The peak UVOIR bolometric luminosities range by a factor of 10 (from 5 × 1041 to 5 × 1042 erg s-1), and the R-band peak varies from M R,peak = -15 to -18. The rise times in all bands are very rapid (<10 days), but the decline rate is slower in the red than in the blue due to a secondary near-IR brightening. The nucleosynthesis primarily yields heavy α-chain elements (40Ca through 56Ni) and unburnt He. Thus, the spectra around peak light lack signs of intermediate-mass elements and are dominated by Ca II and Ti II features, with the caveat that our radiative transfer code does not include the nonthermal effects necessary to produce He features.

  6. THE RETURN OF THE BURSTS: THERMONUCLEAR FLASHES FROM CIRCINUS X-1

    SciTech Connect

    Linares, M.; Homan, J.; Chakrabarty, D.; Watts, A.; Altamirano, D.; Degenaar, N.; Yang, Y.; Wijnands, R.; Armas-Padilla, M.; Cavecchi, Y.; Kalamkar, M.; Kaur, R.; Patruno, A.; Van der Klis, M.; Soleri, P.; Casella, P.; Rea, N.

    2010-08-10

    We report the detection of 15 X-ray bursts with RXTE and Swift observations of the peculiar X-ray binary Circinus X-1 (Cir X-1) during its 2010 May X-ray re-brightening. These are the first X-ray bursts observed from the source after the initial discovery by Tennant and collaborators, 25 years ago. By studying their spectral evolution, we firmly identify nine of the bursts as type I (thermonuclear) X-ray bursts. We obtain an arcsecond location of the bursts that confirms once and for all the identification of Cir X-1 as a type I X-ray burst source, and therefore as a low magnetic field accreting neutron star. The first five bursts observed by RXTE are weak and show approximately symmetric light curves, without detectable signs of cooling along the burst decay. We discuss their possible nature. Finally, we explore a scenario to explain why Cir X-1 shows thermonuclear bursts now but not in the past, when it was extensively observed and accreting at a similar rate.

  7. 30S(α , p) Thermonuclear Reaction Rate from Experimental Level Structure of 34Ar

    NASA Astrophysics Data System (ADS)

    Kahl, D.; Chen, A. A.; Kubono, S.; Yamaguchi, H.; Binh, D. N.; Chen, J.; Cherubini, S.; Duy, N. N.; Hashimoto, T.; Hayakawa, S.; Iwasa, N.; Jung, H. S.; Kato, S.; Kwon, Y. K.; Nishimura, S.; Ota, S.; Setoodehnia, K.; Teranishi, T.; Tokieda, H.; Yamada, T.; Yun, C. C.; Zhang, L. Y.

    Type I X-ray bursts are the most frequent thermonuclear explosions in the galaxy. Owing to their recurrence from known astronomical objects, burst morphology is extensively documented, and they are modeled very successfully as neutron-deficient, thermonuclear runaway on the surface of accreting neutron stars. While reaction networks include hundreds of isotopes and thousands of nuclear processes, only a small subset appear to play a pivotal role. One such reaction is the 30S(α , p) reaction, which is believed to be a crucial link in the explosive helium burning which is responsible for the large energy flux. However, very little experimental information is available concerning the cross section itself, nor the 34Ar compound nucleus at the relevant energies. We performed the first study of the entrance channel via 30S alpha resonant elastic scattering using a state-of-the-art, low-energy, 30S radioactive ion beam. The measurement was performed in inverse kinematics using a newly-developed active target. An R-matrix analysis of the excitation function reveals previously unknown resonances, including their quantum properties of spin, parity, width, and energy.

  8. Matching of experimental and statistical-model thermonuclear reaction rates at high temperatures

    NASA Astrophysics Data System (ADS)

    Newton, Joseph; Longland, Richard; Iliadis, Christian

    2009-05-01

    Reliable reaction rates at high stellar temperatures are necessary for the study of advanced stellar burning stages, supernovae and x-ray bursts. We suggest a new procedure for extrapolating experimental thermonuclear reaction rates to these higher temperatures (T > 1 GK) using statistical model (Hauser-Feshbach) results. Current, generally accepted, procedures involve the use of the Gamow peak, which has been shown to be unreliable for narrow resonances at high stellar temperatures [1]. Our new approach defines the effective thermonuclear energy range (ETER) by using the 8^th, 50^th and 92^nd percentiles of the cumulative distribution of fractional resonant reaction contributions. The ETER is then used to define a reliable temperature for matching experimental rates to Hauser-Feshbach rates. The resulting matching temperature is often well above the previous result using the Gamow peak concept. Our new method should provide more accurate extrapolated rates since Hauser-Feshbach rates are more reliable at higher temperatures. These ideas are applied to 21 (p,γ), (p,α) and (α,γ) reactions on a range of A = 20-40 target nuclei and results will be presented. [0pt] [1] J. R. Newton, C. Iliadis, A. E. Champagne, A. Coc, Y. Parpottas and R. Ugalde, Phys. Rev. C 75, 045801 (2007).

  9. Matching of experimental and statistical-model thermonuclear reaction rates at high temperatures

    NASA Astrophysics Data System (ADS)

    Newton, J. R.; Longland, R.; Iliadis, C.

    2008-08-01

    We address the problem of extrapolating experimental thermonuclear reaction rates toward high stellar temperatures (T>1 GK) by using statistical model (Hauser-Feshbach) results. Reliable reaction rates at such temperatures are required for studies of advanced stellar burning stages, supernovae, and x-ray bursts. Generally accepted methods are based on the concept of a Gamow peak. We follow recent ideas that emphasized the fundamental shortcomings of the Gamow peak concept for narrow resonances at high stellar temperatures. Our new method defines the effective thermonuclear energy range (ETER) by using the 8th, 50th, and 92nd percentiles of the cumulative distribution of fractional resonant reaction rate contributions. This definition is unambiguous and has a straightforward probability interpretation. The ETER is used to define a temperature at which Hauser-Feshbach rates can be matched to experimental rates. This matching temperature is usually much higher compared to previous estimates that employed the Gamow peak concept. We suggest that an increased matching temperature provides more reliable extrapolated reaction rates since Hauser-Feshbach results are more trustwhorthy the higher the temperature. Our ideas are applied to 21 (p,γ), (p,α), and (α,γ) reactions on A=20-40 target nuclei. For many of the cases studied here, our extrapolated reaction rates at high temperatures differ significantly from those obtained using the Gamow peak concept.

  10. Restless “Lower Back” in a Patient with Parkinson’s Disease

    PubMed Central

    Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Hirata, Koichi

    2013-01-01

    Background In restless legs syndrome (RLS), the isolated involvement of other body parts in the absence of leg involvement is rare. Case report We report an 82-year-old male with a 1-year history of Parkinson’s disease (PD) who developed an abnormal sensation limited to his “lower back.” He fulfilled the four essential RLS criteria, with the major caveat that the criteria were applied in a modified manner to his lower back rather than his legs. The administration of a dopamine agonist completely eliminated his symptoms. Discussion Our patient’s “restless lower back” may be a variant of RLS. Clinicians should pay attention to restlessness in other body parts in addition to the legs. PMID:24255803

  11. Algorithms for the diagnosis and treatment of restless legs syndrome in primary care

    PubMed Central

    2011-01-01

    Background Restless legs syndrome (RLS) is a neurological disorder with a lifetime prevalence of 3-10%. in European studies. However, the diagnosis of RLS in primary care remains low and mistreatment is common. Methods The current article reports on the considerations of RLS diagnosis and management that were made during a European Restless Legs Syndrome Study Group (EURLSSG)-sponsored task force consisting of experts and primary care practioners. The task force sought to develop a better understanding of barriers to diagnosis in primary care practice and overcome these barriers with diagnostic and treatment algorithms. Results The barriers to diagnosis identified by the task force include the presentation of symptoms, the language used to describe them, the actual term "restless legs syndrome" and difficulties in the differential diagnosis of RLS. Conclusion The EURLSSG task force reached a consensus and agreed on the diagnostic and treatment algorithms published here. PMID:21352569

  12. The TDF System for Thermonuclear Plasma Reaction Rates, Mean Energies and Two-Body Final State Particle Spectra

    SciTech Connect

    Warshaw, S I

    2001-07-11

    The rate of thermonuclear reactions in hot plasmas as a function of local plasma temperature determines the way in which thermonuclear ignition and burning proceeds in the plasma. The conventional model approach to calculating these rates is to assume that the reacting nuclei in the plasma are in Maxwellian equilibrium at some well-defined plasma temperature, over which the statistical average of the reaction rate quantity {sigma}v is calculated, where {sigma} is the cross-section for the reaction to proceed at the relative velocity v between the reacting particles. This approach is well-understood and is the basis for much nuclear fusion and astrophysical nuclear reaction rate data. The Thermonuclear Data File (TDF) system developed at the Lawrence Livermore National Laboratory (Warshaw 1991), which is the topic of this report, contains data on the Maxwellian-averaged thermonuclear reaction rates for various light nuclear reactions and the correspondingly Maxwellian-averaged energy spectra of the particles in the final state of those reactions as well. This spectral information closely models the output particle and energy distributions in a burning plasma, and therefore leads to more accurate computational treatments of thermonuclear burn, output particle energy deposition and diagnostics, in various contexts. In this report we review and derive the theoretical basis for calculating Maxwellian-averaged thermonuclear reaction rates, mean particle energies, and output particle spectral energy distributions for these reactions in the TDF system. The treatment of the kinematics is non-relativistic. The current version of the TDF system provides exit particle energy spectrum distributions for two-body final state reactions only. In a future report we will discuss and describe how output particle energy spectra for three- and four-body final states can be developed for the TDF system. We also include in this report a description of the algorithmic implementation of the

  13. Two-sided conical laser target for a neutron source of a hybrid nuclear-thermonuclear reactor

    NASA Astrophysics Data System (ADS)

    Lebo, I. G.; Isaev, E. A.; Lebo, A. I.

    2017-03-01

    Numerical simulations suggest that a source of thermonuclear neutrons with a high pulse repetition rate and the number of neutrons of ~1017 per pulse, which is required for the development of nuclear-thermonuclear reactors, can be realised in the irradiation of a two-sided conical target simultaneously by a long and short laser pulses with energies of ~1 MJ and 50 kJ and durations of 100 – 250 ns and 0.1 – 1 ns. We consider the feasibility of verifying separate propositions of the proposed conception with the use of existing laser facilities.

  14. Effect of Sensory Stimuli on Restless Legs Syndrome: A Randomized Crossover Study

    PubMed Central

    Rozeman, Anouk D.; Ottolini, Truus; Grootendorst, Diana C.; Vogels, Oscar J.M.; Rijsman, Roselyne M.

    2014-01-01

    Study Objective: A variety of sensory stimuli relieve restless legs syndrome symptoms. Because systematic evaluations of sensory stimulation in restless legs syndrome are largely lacking, we performed a randomized crossover study to evaluate the effect of external sensory stimulation on restless legs syndrome symptoms. Methods: Eighteen patients underwent 3 consecutive suggestive immobilization tests with the order of the following 3 conditions randomly assigned: no electrical stimulation (condition 1), tactile and proprioceptive sensory stimulation (condition 2), and tactile sensory stimulation only (condition 3). Restless legs syndrome symptoms were quantified by visual analog scales, and periodic leg movements during wake were measured. Results: Baseline visual analogue scale score was 4.5 (range 0-60) in condition 1, 10.5 (range 0-96) in condition 2, and 8.5 in condition 3 (p = 0.21). There was a tendency towards a higher maximum visual analogue scale score and visual analogue scale score at the end of the suggested immobilization test in the conditions with tactile sensory stimulation, though not significant (p = 0.74 and p = 0.29, respectively). Fifteen patients suffered from periodic leg movements during wake. Median indices were 18 (range 0-145) in condition 1, 26 (range 0-190) in condition 2, and 49 (range 0-228) in condition 3 (p = 0.76). Conclusions: We found a tendency towards less leg discomfort in the conditions in which an external sensory input was applied. This potential benefit of sensory stimuli on restless legs syndrome severity merits further investigation as this could open new ways towards a better pathophysiological understanding and non-pharmacological treatments. Citation: Rozeman AD, Ottolini T, Grootendorst DC, Vogels OJM, Rijsman RM. Effect of sensory stimuli on restless legs syndrome: a randomized crossover study. J Clin Sleep Med 2014;10(8):893-896. PMID:25126036

  15. Diagnostic Accuracy of Behavioral, Activity, Ferritin, and Clinical Indicators of Restless Legs Syndrome

    PubMed Central

    Richards, Kathy C.; Bost, James E.; Rogers, Valerie E.; Hutchison, Lisa C.; Beck, Cornelia K.; Bliwise, Donald L.; Kovach, Christine R.; Cuellar, Norma; Allen, Richard P.

    2015-01-01

    Study Objectives: Lack of a valid diagnostic measure of restless legs syndrome (RLS) for persons with dementia, who do not have the cognitive ability to report complex symptoms, impedes RLS treatment and research in this population. The aim of this study was to determine the sensitivity and specificity of a combination of indicators for identifying RLS that could eventually be used to diagnose RLS in persons with dementia. Design: 3-day, prospective instrument validation. Setting: Sleep laboratory. Participants: Cognitively intact, 107 with RLS, 105 without RLS. Interventions: N/A. Measurements: Serial 20-min observations with a new measure, the Behavioral Indicators Test–Restless Legs (BIT-RL); leg movements with 3 nights of the Periodic Activity Monitor–Restless Legs (PAM-RL); ferritin; sleep history; clinical data; polysomnography; Hopkins Telephone Diagnostic Interview of RLS Symptoms. Results: The best-fitting diagnostic model for identifying RLS included previous history of iron deficiency (odds ratio [OR] 7.30), leg discomfort (OR 6.47), daytime fatigue (OR 6.15), difficulty falling asleep (OR 3.25), RLS family history (OR 2.60), BIT-RL (OR 1.49), and absence of diabetes (OR 0.27), with sensitivity 78%, specificity 79%, and 77% correctly classified. This model retained its predictive accuracy even with co-morbid sleep apnea. Conclusions: When compared to those without restless legs syndrome (RLS), persons with RLS have observable behaviors, such as rubbing the legs, that differentiate them, but the behaviors have no circadian and activity-related variability. The final model of clinical and sleep historical data and observation for RLS behaviors using the Behavioral Indicators Test–Restless Legs had good diagnostic accuracy. Citation: Richards KC, Bost JE, Rogers VE, Hutchison LC, Beck CK, Bliwise DL, Kovach CR, Cuellar N, Allen RP. Diagnostic accuracy of behavioral, activity, ferritin, and clinical indicators of restless legs syndrome. SLEEP 2015

  16. Motor hyperactivity of the iron-deficient rat - an animal model of restless legs syndrome.

    PubMed

    Lai, Yuan-Yang; Cheng, Yu-Hsuan; Hsieh, Kung-Chiao; Nguyen, Darian; Chew, Keng-Tee; Ramanathan, Lalini; Siegel, Jerome M

    2017-08-26

    Abnormal striatal dopamine transmission has been hypothesized to cause restless legs syndrome. Dopaminergic drugs are commonly used to treat restless legs syndrome. However, they cause adverse effects with long-term use. An animal model would allow the systematic testing of potential therapeutic drugs. A high prevalence of restless legs syndrome has been reported in iron-deficient anemic patients. We hypothesized that the iron-deficient animal would exhibit signs similar to those in restless legs syndrome patients. After baseline polysomnographic recordings, iron-deficient rats received pramipexole injection. Then, iron-deficient rats were fed a standard rodent diet, and polysomnographic recording were performed for 2 days each week for 4 weeks. Iron-deficient rats have low hematocrit levels and show signs of restless legs syndrome: sleep fragmentation and periodic leg movements in wake and in slow-wave sleep. Iron-deficient rats had a positive response to pramipexole treatment. After the iron-deficient rats were fed the standard rodent diet, hematocrit returned to normal levels, and sleep quality improved, with increased average duration of wake and slow-wave sleep episodes. Periodic leg movements decreased during both waking and sleep. Hematocrit levels positively correlated with the average duration of episodes in wake and in slow-wave sleep and negatively correlated with periodic leg movements in wake and in sleep. Western blot analysis showed that striatal dopamine transporter levels were higher in iron-deficient rats. The iron-deficient rat is a useful animal model of iron-deficient anemic restless legs syndrome. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  17. Sleep disorders: A review of the interface between restless legs syndrome and iron metabolism

    PubMed Central

    Daubian-Nosé, Paulo; Frank, Miriam K.; Esteves, Andrea Maculano

    2014-01-01

    Restless legs syndrome (RLS) is characterized by unpleasant sensations mainly in the legs. 43% of RLS-associated conditions have also been associated with systemic iron deficiency. The objective of this study was to review in the literature the relationship between iron metabolism and RLS. With an initial search using the keywords combination “Iron Metabolism OR Iron Deficiency AND Restless Legs Syndrome,” 145 articles were screened, and 20 articles were selected. Few studies were found for this review in the period of 2001–2014, however, the correlation between RLS and iron was evident. PMID:26483934

  18. Association of incident restless legs syndrome with outcomes in a large cohort of US veterans.

    PubMed

    Molnar, Miklos Z; Lu, Jun L; Kalantar-Zadeh, Kamyar; Kovesdy, Csaba P

    2016-02-01

    Restless legs syndrome is a common sleep disorder, but there is a paucity of large cohort studies examining the association of restless legs syndrome with clinical outcomes, including all-cause mortality, incident coronary heart disease, stroke and chronic kidney disease. From a nationally representative prospective cohort of over 3 million US veterans [93% male, median follow-up time of 8.1 years (interquartile range: 7.0-8.5 years)] with baseline estimated glomerular filtration rate ≥ 60 mL min(-1) 1.73 m(-2), a propensity-matched cohort of 7392 patients was created, and the association between incident restless legs syndrome and the following was examined: (1) all-cause mortality; (2) incident coronary heart disease; (3) incident strokes; and (4) incident chronic kidney disease defined as estimated glomerular filtration rate <60 mL min(-1) 1.73 m(-2). Associations were examined using Cox models. The mean ± SD age of the propensity-matched cohort at baseline was 59 ± 12 years; 89 and 8% of patients were white and black, respectively; 31% of the patients were diabetic; and the mean baseline estimated glomerular filtration rate was 83.9 ± 15.1 mL min(-1) 1.73 m(-2). Propensity matching resulted in a balanced cohort, with the disappearance in baseline differences in comorbidities. Compared with restless legs syndrome-negative patients, incident restless legs syndrome was associated with 88% higher mortality risk [hazard ratio and 95% confidence interval: 1.88 (1.70-2.08)], and almost four times higher risk of coronary heart disease and stroke [hazard ratio: 3.97 (3.26-4.84) and 3.89 (3.07-4.94), respectively]. The risk of incident chronic kidney disease was also significantly higher in incident restless legs syndrome patients [hazard ratio: 3.17 (2.74-3.66)] compared with restless legs syndrome-negative counterparts. In this large and contemporary cohort of US veterans, incident restless legs syndrome was associated with higher risk of mortality, incident

  19. Stress tolerance during diapause and quiescence of the brine shrimp, Artemia.

    PubMed

    MacRae, Thomas H

    2016-01-01

    Oviparously developing embryos of the brine shrimp, Artemia, arrest at gastrulation and are released from females as cysts before entering diapause, a state of dormancy and stress tolerance. Diapause is terminated by an external signal, and growth resumes if conditions are permissible. However, if circumstances are unfavorable, cysts enter quiescence, a dormant stage that continues as long as adverse conditions persist. Artemia embryos in diapause and quiescence are remarkably resistant to environmental and physiological stressors, withstanding desiccation, cold, heat, oxidation, ultraviolet radiation, and years of anoxia at ambient temperature when fully hydrated. Cysts have adapted to stress in several ways; they are surrounded by a rigid cell wall impermeable to most chemical compounds and which functions as a shield against ultraviolet radiation. Artemia cysts contain large amounts of trehalose, a non-reducing sugar thought to preserve membranes and proteins during desiccation by replacing water molecules and/or contributing to vitrification. Late embryogenesis abundant proteins similar to those in seeds and other anhydrobiotic organisms are found in cysts, and they safeguard cell organelles and proteins during desiccation. Artemia cysts contain abundant amounts of p26, a small heat shock protein, and artemin, a ferritin homologue, both ATP-independent molecular chaperones important in stress tolerance. The evidence provided in this review supports the conclusion that it is the interplay of these protective elements that make Artemia one of the most stress tolerant of all metazoan organisms.

  20. Degassing during quiescence as a trigger of magma ascent and volcanic eruptions

    PubMed Central

    Girona, Társilo; Costa, Fidel; Schubert, Gerald

    2015-01-01

    Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. The hyperactivity of these volcanoes results from frequent pressurizations of the shallow magma plumbing system, which in most cases are thought to occur by the ascent of magma from deep to shallow reservoirs. However, the driving force that causes magma ascent from depth remains unknown. Here we demonstrate that magma ascent can be triggered by the passive release of gas during quiescence, which induces the opening of pathways connecting deep and shallow magma reservoirs. This top-down mechanism for volcanic eruptions contrasts with the more common bottom-up mechanisms in which magma ascent is only driven by processes occurring at depth. A cause-effect relationship between passive degassing and magma ascent can explain the fact that repose times are typically much longer than unrest times preceding eruptions, and may account for the so frequent unrest episodes of persistently degassing volcanoes. PMID:26666396

  1. The Bhc Soft X-Ray Transient XTE J1908+094 Returning to Quiescence

    NASA Astrophysics Data System (ADS)

    Jonker, Peter

    2002-09-01

    With the Chandra satellite we can study the spectra of SXTs as they fade into quiescence. This has never been done for a BHC SXT! According to evolutionary and SXT outburst theories there may exist a whole class of persistent but faint accreting BHCs at low Mdot; their accretion disk is cold and hence not prone to the SXT outburst mechanism. Up to now there is very few information on spectral states for BHCs for ~2 orders of magnitude in flux (~10^-7-10^-5 Edd.; there is spectral information of BHCs in quiescence at ~10^-8 of Edd.). Gallo et al. 2003 have demonstrated the existence of a universal coupling between observed X-ray and radio flux from hard state BHCs, of the form L_radio~L_X^0.7, over three orders of magnitude. We propose to extend this relation down to ~5x10^-7 Edd. assuming d=10 kpc. This would demonstrate that jet production is the standard behavior and it is only in the limited range in Mdot in which a standard thin disc is formed that a jet is not produced.

  2. Mechanisms of paracrine regulation by fetal membranes of human uterine quiescence.

    PubMed

    Carvajal, Jorge A; Vidal, Rossana J; Cuello, Mauricio A; Poblete, Jose A; Weiner, Carl P

    2006-07-01

    To test the hypothesis that fetal membranes (chorion or amnion) release one or more factors responsible for myometrial quiescence. Myometrial samples were excised from women at elective term cesarean delivery prior to the onset of labor. Fetal membranes were obtained after cesarean delivery either before or during labor, and either term (greater than 37 weeks) or preterm (less than or equal to 36 weeks). Myometrial strips were placed in organ baths and contractions stimulated by oxytocin (10(-8) M). Contractility was measured under isometric conditions before and after exposure to fetal membranes or conditioned medium. The impact of either membrane or conditioned media on contractility was determined before and after myometrial K+ channel blockade. Both chorion and amnion and their respective conditioned mediums decrease oxytocin-stimulated myometrial contraction. The inhibitory effect was greatest with membranes from preterm pregnancies (mean gestation 32 weeks, P <.05). The inhibitory effect was detectable in the presence of term labor, but was absent when the fetal membranes were obtained after preterm labor. Iberiotoxin, an inhibitor of large conductance Ca2+-activated K+ channels (BK(Ca)) reduced the effect of fetal membranes by 50% (P <.05). We conclude that human fetal membranes release one or more factors that inhibit oxytocin-induced myometrial contractility. We suggest this factor (or factors) acts mainly by opening myometrial BK(Ca). The findings further support our hypothesis that the fetal membranes release a factor (or factors) that is central to myometrial quiescence and its premature loss leads to preterm delivery.

  3. NR2F1 controls tumor cell dormancy via SOX9 and RARβ driven quiescence programs

    PubMed Central

    Sosa, Maria Soledad; Parikh, Falguni; Maia, Alexandre Gaspar; Estrada, Yeriel; Bosch, Almudena; Bragado, Paloma; Ekpin, Esther; George, Ajish; Zheng, Yang; Lam, Hung-Ming; Morrissey, Colm; Chung, Chi-Yeh; Farias, Eduardo F.; Bernstein, Emily; Aguirre-Ghiso, Julio A.

    2014-01-01

    Metastases can originate from disseminated tumor cells (DTCs), which may be dormant for years before reactivation. Here we find that the orphan nuclear receptor NR2F1 is epigenetically upregulated in experimental HNSCC dormancy models and in DTCs from prostate cancer patients carrying dormant disease for 7–18 years. NR2F1-dependent dormancy is recapitulated by a co-treatment with the DNA demethylating agent 5-Aza-C and retinoic acid across various cancer types. NR2F1-induced quiescence is dependent on SOX9, RARβ and CDK inhibitors. Intriguingly, NR2F1 induces global chromatin repression and the pluripotency gene NANOG, which contributes to dormancy of DTCs in the bone marrow. When NR2F1 is blocked in vivo, growth arrest or survival of dormant DTCs is interrupted in different organs. We conclude that NR2F1 is a critical node in dormancy induction and maintenance by integrating epigenetic programs of quiescence and survival in DTCs. PMID:25636082

  4. Dclk1+ small intestinal epithelial tuft cells display the hallmarks of quiescence and self-renewal

    PubMed Central

    Chandrakesan, Parthasarathy; May, Randal; Qu, Dongfeng; Weygant, Nathaniel; Taylor, Vivian E.; Li, James D.; Ali, Naushad; Sureban, Sripathi M.; Qante, Michael; Wang, Timothy C.; Bronze, Michael S.; Houchen, Courtney W.

    2015-01-01

    To date, no discrete genetic signature has been defined for isolated Dclk1+ tuft cells within the small intestine. Furthermore, recent reports on the functional significance of Dclk1+ cells in the small intestine have been inconsistent. These cells have been proposed to be fully differentiated cells, reserve stem cells, and tumor stem cells. In order to elucidate the potential function of Dclk1+ cells, we FACS-sorted Dclk1+ cells from mouse small intestinal epithelium using transgenic mice expressing YFP under the control of the Dclk1 promoter (Dclk1-CreER;Rosa26-YFP). Analysis of sorted YFP+ cells demonstrated marked enrichment (~6000 fold) for Dclk1 mRNA compared with YFP− cells. Dclk1+ population display ~6 fold enrichment for the putative quiescent stem cell marker Bmi1. We observed significantly greater expression of pluripotency genes, pro-survival genes, and quiescence markers in the Dclk1+ population. A significant increase in self-renewal capability (14-fold) was observed in in vitro isolated Dclk1+ cells. The unique genetic report presented in this manuscript suggests that Dclk1+ cells may maintain quiescence, pluripotency, and metabolic activity for survival/longevity. Functionally, these reserve characteristics manifest in vitro, with Dclk1+ cells exhibiting greater ability to self-renew. These findings indicate that quiescent stem-like functionality is a feature of Dclk1-expressing tuft cells. PMID:26362399

  5. Msi RNA-binding proteins control reserve intestinal stem cell quiescence.

    PubMed

    Yousefi, Maryam; Li, Ning; Nakauka-Ddamba, Angela; Wang, Shan; Davidow, Kimberly; Schoenberger, Jenna; Yu, Zhengquan; Jensen, Shane T; Kharas, Michael G; Lengner, Christopher J

    2016-11-07

    Regeneration of the intestinal epithelium is driven by multiple intestinal stem cell (ISC) types, including an active, radiosensitive Wnt(high) ISC that fuels turnover during homeostasis and a reserve, radioresistant Wnt(low/off) ISC capable of generating active Wnt(high) ISCs. We examined the role of the Msi family of oncoproteins in the ISC compartment. We demonstrated that Msi proteins are dispensable for normal homeostasis and self-renewal of the active ISC, despite their being highly expressed in these cells. In contrast, Msi proteins are required specifically for activation of reserve ISCs, where Msi activity is both necessary and sufficient to drive exit from quiescence and entry into the cell cycle. Ablation of Msi activity in reserve ISCs rendered the epithelium unable to regenerate in response to injury that ablates the active stem cell compartment. These findings delineate a molecular mechanism governing reserve ISC quiescence and demonstrate a necessity for the activity of this rare stem cell population in intestinal regeneration. © 2016 Yousefi et al.

  6. The Dwarf Novae Ty Psc and V436 Cen During Quiescence: Exposed White Dwarfs?

    NASA Astrophysics Data System (ADS)

    Nadalin, I.; Sion, E. M.

    2000-12-01

    The dwarf novae TY Psc and V436 Cen are SU UMa systems with very similar orbital periods, similar recurrence times for normal outbursts ( 23 days) and superoutbursts ( ~ 340 days) and nearly identical outburst amplitudes. We have applied the Massa-Fitzpatrick (2000) flux calibration correction to the archival IUE NEWSIPS SWP spectra of these two systems, obtained during dwarf nova quiescence. We have carried out high gravity model atmosphere using the codes TLUSTY195, SYNSPEC42, ROTIN and accretion disk synthetic spectra from the grid of Wade and Hubeny (1998). We present our results on the physical properties of the underlying white dwarf accreters, including temperature, gravity, chemical abundances estimates, and the accretion rate during quiescence. We discuss our results in the context of the overall picture of accretion physics in dwarf novae and the effects of accretion on the white dwarf. This research was supported in part by NSF grant AST 99-01955, NASA ADP grant NAG5-8388 and by summer research funding from the NASA- Delaware Space Grant Colleges Consortium.

  7. Post-transcriptional regulation of satellite cell quiescence by TTP-mediated mRNA decay

    PubMed Central

    Hausburg, Melissa A; Doles, Jason D; Clement, Sandra L; Cadwallader, Adam B; Hall, Monica N; Blackshear, Perry J; Lykke-Andersen, Jens; Olwin, Bradley B

    2015-01-01

    Skeletal muscle satellite cells in their niche are quiescent and upon muscle injury, exit quiescence, proliferate to repair muscle tissue, and self-renew to replenish the satellite cell population. To understand the mechanisms involved in maintaining satellite cell quiescence, we identified gene transcripts that were differentially expressed during satellite cell activation following muscle injury. Transcripts encoding RNA binding proteins were among the most significantly changed and included the mRNA decay factor Tristetraprolin. Tristetraprolin promotes the decay of MyoD mRNA, which encodes a transcriptional regulator of myogenic commitment, via binding to the MyoD mRNA 3′ untranslated region. Upon satellite cell activation, p38α/β MAPK phosphorylates MAPKAP2 and inactivates Tristetraprolin, stabilizing MyoD mRNA. Satellite cell specific knockdown of Tristetraprolin precociously activates satellite cells in vivo, enabling MyoD accumulation, differentiation and cell fusion into myofibers. Regulation of mRNAs by Tristetraprolin appears to function as one of several critical post-transcriptional regulatory mechanisms controlling satellite cell homeostasis. DOI: http://dx.doi.org/10.7554/eLife.03390.001 PMID:25815583

  8. Fibroblast spheroids as a model to study sustained fibroblast quiescence and their crosstalk with tumor cells.

    PubMed

    Salmenperä, Pertteli; Karhemo, Piia-Riitta; Räsänen, Kati; Laakkonen, Pirjo; Vaheri, Antti

    2016-07-01

    Stromal fibroblasts have an important role in regulating tumor progression. Normal and quiescent fibroblasts have been shown to restrict and control cancer cell growth, while cancer-associated, i. e. activated fibroblasts have been shown to enhance proliferation and metastasis of cancer cells. In this study we describe generation of quiescent fibroblasts in multicellular spheroids and their effects on squamous cell carcinoma (SCC) growth in soft-agarose and xenograft models. Quiescent phenotype of fibroblasts was determined by global down-regulation of expression of genes related to cell cycle and increased expression of p27. Interestingly, microarray analysis showed that fibroblast quiescence was associated with similar secretory phenotype as seen in senescence and they expressed senescence-associated-β-galactosidase. Quiescent fibroblasts spheroids also restricted the growth of RT3 SCC cells both in soft-agarose and xenograft models unlike proliferating fibroblasts. Restricted tumor growth was associated with marginally increased tumor cell senescence and cellular differentiation, showed with senescence-associated-β-galactosidase and cytokeratin 7 staining. Our results show that the fibroblasts spheroids can be used as a model to study cellular quiescence and their effects on cancer cell progression. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Degassing during quiescence as a trigger of magma ascent and volcanic eruptions.

    PubMed

    Girona, Társilo; Costa, Fidel; Schubert, Gerald

    2015-12-15

    Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. The hyperactivity of these volcanoes results from frequent pressurizations of the shallow magma plumbing system, which in most cases are thought to occur by the ascent of magma from deep to shallow reservoirs. However, the driving force that causes magma ascent from depth remains unknown. Here we demonstrate that magma ascent can be triggered by the passive release of gas during quiescence, which induces the opening of pathways connecting deep and shallow magma reservoirs. This top-down mechanism for volcanic eruptions contrasts with the more common bottom-up mechanisms in which magma ascent is only driven by processes occurring at depth. A cause-effect relationship between passive degassing and magma ascent can explain the fact that repose times are typically much longer than unrest times preceding eruptions, and may account for the so frequent unrest episodes of persistently degassing volcanoes.

  10. The Thermal State of KS 1731-260 after 14.5 years in Quiescence

    NASA Astrophysics Data System (ADS)

    Merritt, Rachael L.; Cackett, Edward M.; Brown, Edward F.; Page, Dany; Cumming, Andrew; Degenaar, Nathalie; Deibel, Alex; Homan, Jeroen; Miller, Jon M.; Wijnands, Rudy

    2016-12-01

    Crustal cooling of accretion-heated neutron stars provides insight into the stellar interior of neutron stars. The neutron star X-ray transient, KS 1731-260, was in outburst for 12.5 years before returning to quiescence in 2001. We have monitored the cooling of this source since then through Chandra and XMM-Newton observations. Here we present a 150 ks Chandra observation of KS 1731-260 taken in 2015 August, about 14.5 years into quiescence and 6 years after the previous observation. We find that the neutron star surface temperature is consistent with the previous observation, suggesting that crustal cooling has likely stopped and the crust has reached thermal equilibrium with the core. Using a theoretical crust thermal evolution code, we fit the observed cooling curves and constrain the core temperature (T c = 9.35 ± 0.25 × 107 K), composition (Q {}{imp}={4.4}-0.5+2.2), and level of extra shallow heating required (Q sh = 1.36 ± 0.18 MeV/nucleon). We find that the presence of a low thermal conductivity layer, as expected from nuclear pasta, is not required to fit the cooling curve well, but cannot be excluded either.

  11. Degassing during quiescence as a trigger of magma ascent and volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Girona, Társilo; Costa, Fidel; Schubert, Gerald

    2015-12-01

    Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. The hyperactivity of these volcanoes results from frequent pressurizations of the shallow magma plumbing system, which in most cases are thought to occur by the ascent of magma from deep to shallow reservoirs. However, the driving force that causes magma ascent from depth remains unknown. Here we demonstrate that magma ascent can be triggered by the passive release of gas during quiescence, which induces the opening of pathways connecting deep and shallow magma reservoirs. This top-down mechanism for volcanic eruptions contrasts with the more common bottom-up mechanisms in which magma ascent is only driven by processes occurring at depth. A cause-effect relationship between passive degassing and magma ascent can explain the fact that repose times are typically much longer than unrest times preceding eruptions, and may account for the so frequent unrest episodes of persistently degassing volcanoes.

  12. Restless legs syndrome: differential diagnosis and management with pramipexole

    PubMed Central

    Brindani, Francesca; Vitetta, Francesca; Gemignani, Franco

    2009-01-01

    Restless legs syndrome (RLS) is a condition characterized by discomfort at rest and urge to move focused on the legs. RLS may occur as an idiopathic, often hereditary condition (primary RLS), or in association with medical conditions (secondary RLS) including iron deficiency, uremia, and polyneuropathy. Current understanding of the pathophysiology of RLS points to the involvement of three interrelated components: dopaminergic dysfunction, impaired iron homeostasis, and genetic mechanisms. The diagnosis of RLS is made according to the consensus criteria by a National Institutes of Health panel: 1) an urge to move the legs, usually accompanied by uncomfortable sensations; 2) beginning or worsening during rest; 3) relieved by movement; and 4) worse, or only occurring, in the evening or at night. The differential diagnosis of RLS aims to: 1) distinguish RLS from other disorders with RLS-like symptoms and 2) identify secondary forms, with investigation of underlying diseases. The treatment of RLS demands a clinical evaluation to rule out and cure causes of secondary RLS, including iron supplementation when deficient, and to eliminate the triggering factors. The presence of neuropathy should be especially investigated in nonhereditary, late-onset RLS, in view of a possible treatment of the underlying disease. The first line treatment for idiopathic RLS is represented by dopamine agonists, in particular nonergot-derived ropinirole and pramipexole, whereas ergot dopamine agonists (cabergoline and pergolide) are no longer in first-line use given the risks of cardiac valvulopathy. Although no comparative trials have been published, a meta-analysis of pramipexole versus ropinirole suggests differences in efficacy and tolerability favoring pramipexole. PMID:19750232

  13. Predictive factors of restless leg syndrome in hemodialysis patients

    PubMed Central

    Eftekhari, Adel; Nasiriani, Khadijeh; Mirzaei, Samaneh; Azimpour Ardakani, Somayeh

    2016-01-01

    Introduction: The restless leg syndrome (RLS) is a neurologic disorder suffering the hemodialysis patients. Although the pathophysiology of this syndrome remains unknown yet, an investigation of the parameters pertinent to it may help to develop the related medical knowledge and to improve the therapeutic-care interventions in this regard. Objectives: The correlation between the RLSs on individual, clinical, and laboratory indices in patients undergoing hemodialysis. Patients and Methods: This descriptive-analytic study was conducted on 104 hemodialysis patients. Diagnosis of RLS was made using the International RLS Standard Questionnaire. The data on individual, clinical, and laboratory indices were obtained from patients’ recorded files and interviews. Results: Based on our findings, 28.8% of the patients undergoing hemodialysis were affected with mild RLS, 41.7% with moderate RLS, and 29.5% with severe RLS. There was a statistically significant correlation between affliction with RLS on the one hand, and age and gender, on the other (P < 0.05). However, there was no significant correlation between RLS and education level, occupation, length of hemodialysis, fasting blood sugar (FBS), hepatitis B and C, serum blood urea nitrogen (BUN), creatinine (Cr), iron, hemoglobin (Hb) level and also KT/Vor URR (P < 0.05). Conclusion: Regarding the high prevalence of RLS among the hemodialysis patients, there is the necessity for taking more care of these patients to reduce the somatic complications of the RLS especially among the elderly and female patients and to control the blood sugar of these patients at the normal level. PMID:27471741

  14. Parathyroidectomy Improves Restless Leg Syndrome in Patients on Hemodialysis

    PubMed Central

    Santos, Roberto Sávio Silva; Coelho, Fernando Morgadinho Santos; da Silva, Bruno Caldin; Graciolli, Fabiana Giorgeti; Dominguez, Wagner Velasquez; de Menezes Montenegro, Fabio Luiz; Jorgetti, Vanda; Moysés, Rosa Maria Affonso; Elias, Rosilene Motta

    2016-01-01

    Background Restless leg syndrome (RLS) is a sleep disorder with high prevalence among patients on hemodialysis. It has been postulated that high phosphate and high parathyroid hormone may be implicated in its pathogenesis. Standard international criteria and face-to-face interview are not always applied. Methods this was an interventional prospective study in which 19 patients (6 men, aged 48±11 years) with severe hyperparathyroidism were evaluated. RLS diagnosis and rating scale were accessed based on the International RLS Study Group pre- and post-parathyroidectomy. Patients also underwent standard polysomnography. Results At baseline, RLS was present in 10 patients (52.6%), and pain was the most reported symptom associated with the diagnosis. Patients with RLS had higher serum phosphate (p = 0.008) that remained independently associated with RLS in a logistic regression model, adjusted for hemoglobin, age and gender (HR = 7.28;CI = 1.14–46.3, p = 0.035). After parathyroidectomy, there was a reduction of serum parathyroid hormone, phosphate, calcium and alkaline phosphatase, and an increase of 25(OH)-vitamin D, and Fetuin-A. Parathyroidectomy alleviated RLS (from 52% to 21%; p = 0.04), which was accompanied by a decrease in severity scale, in association with relief of pain and pruritus. Polysomnography in these patients showed an improvement of sleep parameters as measured by sleep efficiency, sleep latency and percentage of REM sleep. Conclusion RLS is associated with high levels of phosphate in patients with severe secondary hyperparathyroidism on hemodialysis. Pain is most reported complain in these patients. Parathyroidectomy provided an opportunity to relief RLS. Whether the reduction of serum phosphorus or parathyroid hormone contributed to this improvement merits further investigation. PMID:27196740

  15. Parathyroidectomy Improves Restless Leg Syndrome in Patients on Hemodialysis.

    PubMed

    Santos, Roberto Sávio Silva; Coelho, Fernando Morgadinho Santos; Silva, Bruno Caldin da; Graciolli, Fabiana Giorgeti; Dominguez, Wagner Velasquez; Menezes Montenegro, Fabio Luiz de; Jorgetti, Vanda; Moysés, Rosa Maria Affonso; Elias, Rosilene Motta

    2016-01-01

    Restless leg syndrome (RLS) is a sleep disorder with high prevalence among patients on hemodialysis. It has been postulated that high phosphate and high parathyroid hormone may be implicated in its pathogenesis. Standard international criteria and face-to-face interview are not always applied. this was an interventional prospective study in which 19 patients (6 men, aged 48±11 years) with severe hyperparathyroidism were evaluated. RLS diagnosis and rating scale were accessed based on the International RLS Study Group pre- and post-parathyroidectomy. Patients also underwent standard polysomnography. At baseline, RLS was present in 10 patients (52.6%), and pain was the most reported symptom associated with the diagnosis. Patients with RLS had higher serum phosphate (p = 0.008) that remained independently associated with RLS in a logistic regression model, adjusted for hemoglobin, age and gender (HR = 7.28;CI = 1.14-46.3, p = 0.035). After parathyroidectomy, there was a reduction of serum parathyroid hormone, phosphate, calcium and alkaline phosphatase, and an increase of 25(OH)-vitamin D, and Fetuin-A. Parathyroidectomy alleviated RLS (from 52% to 21%; p = 0.04), which was accompanied by a decrease in severity scale, in association with relief of pain and pruritus. Polysomnography in these patients showed an improvement of sleep parameters as measured by sleep efficiency, sleep latency and percentage of REM sleep. RLS is associated with high levels of phosphate in patients with severe secondary hyperparathyroidism on hemodialysis. Pain is most reported complain in these patients. Parathyroidectomy provided an opportunity to relief RLS. Whether the reduction of serum phosphorus or parathyroid hormone contributed to this improvement merits further investigation.

  16. New treatment options for the management of restless leg syndrome.

    PubMed

    Toro, Beatriz Elizabeth Carmona

    2014-08-01

    Restless leg syndrome (RLS), also known as Willis-Ekbom disease, is a condition that includes sensations such as crawling, tingling, or aching in the limbs and creates an urge to move. The prevalence is estimated at 3% to 15% of the population and may present as primary RLS or secondary RLS. Secondary RLS may be a result of some medications, iron deficiency, or conditions such as neuropathies, or it may be related to pregnancy. The guidelines for diagnosis, which is usually made on clinical presentation, are discussed in the article. Medication use is not always necessary in the management of RLS. Multiple options are available and are reviewed within the article. Since 2011, two medications have been approved for the treatment of RLS, and these are discussed in detail. Neupro (rotigotine) is a dopamine agonist available as a patch that has been approved for the treatment of RLS as well as Parkinson disease. One of the major issues in treating RLS with dopamine agonists is augmentation, meaning symptoms occur earlier in the day due to medication use. This rate of augmentation with use of rotigotine is significantly lower than other dopamine agonists. Horizant (gabapentin enacarbil) is the only nondopaminergic medication approved for the treatment of RLS. Bioavailability is greater in gabapentin enacarbil as compared to gabapentin. Augmentation has not been associated with gabapentin or gabapentin enacarbil. Neupro (rotigotine) and Horizant (gabapentin enacarbil) provide additional treatment options for patients with RLS who are in need of medications. Consideration of each individual patient is necessary when determining if medication is needed and in choosing the appropriate agent.

  17. Restless legs syndrome in dialysis patients: a meta-analysis.

    PubMed

    Mao, Song; Shen, Hua; Huang, Songming; Zhang, Aihua

    2014-12-01

    Restless legs syndrome (RLS) occurs frequently in dialysis patients. However, it remains elusive regarding the risk factors for RLS onset in dialysis patients. A meta-analysis was performed to investigate the association between clinical measures (age, gender, diabetes mellitus or DM etc.) and RLS in dialysis patients. We searched electronic databases from January 1990 to February 2014 to identify studies that met inclusion criteria. Either a fixed-effects or, in the presence of heterogeneity, a random-effects model was used to calculate the pooled odds ratios (ORs)/standard mean differences (SMDs) and their corresponding confidence intervals (CIs). Twenty-three studies were included in this study. Dialysis patients with RLS demonstrated significantly higher OR of DM compared with non-RLS in Asians (OR: 1.238, 95% CI: 1.032-1.484, P = 0.021). Dialysis patients with RLS showed markedly lower level of hemoglobin (Hb)/iron compared with non-RLS in overall populations/Caucasians (SMD: -0.178/-0.104, 95% CI: -0.352/-0.206 to -0.004/-0.002, P = 0.045/0.045; SMD: -0.283/-0.158, 95% CI: -0.552/-0.304 to -0.013/-0.012, P = 0.04/0.034). No differences of female populations, age, duration of dialysis, body mass index (BMI), blood urea nitrogen (BUN), creatinine, albumin, phosphorus, parathyroid hormone (PTH), and calcium were observed between dialysis patients with RLS and non-RLS in overall populations, Caucasians and Asians. No evidence of publication bias was observed. Our findings indicate that dialysis patients with DM are nearly 24% more susceptible to RLS in Asians. Decreased Hb/iron is a risk factor for RLS onset in dialysis patients in overall populations including Caucasians. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Nerve Decompression and Restless Legs Syndrome: A Retrospective Analysis.

    PubMed

    Anderson, James C; Fritz, Megan L; Benson, John-Michael; Tracy, Brian L

    2017-01-01

    Restless legs syndrome (RLS) is a prevalent sleep disorder affecting quality of life and is often comorbid with other neurological diseases, including peripheral neuropathy. The mechanisms related to RLS symptoms remain unclear, and treatment options are often aimed at symptom relief rather than etiology. RLS may present in distinct phenotypes often described as "primary" vs. "secondary" RLS. Secondary RLS is often associated with peripheral neuropathy. Nerve decompression surgery of the common and superficial fibular nerves is used to treat peripheral neuropathy. Anecdotally, surgeons sometimes report improved RLS symptoms following nerve decompression for peripheral neuropathy. The purpose of this retrospective analysis was to quantify the change in symptoms commonly associated with RLS using visual analog scales (VAS). Forty-two patients completed VAS scales (0-10) for pain, burning, numbness, tingling, weakness, balance, tightness, aching, pulling, cramping, twitchy/jumpy, uneasy, creepy/crawly, and throbbing, both before and 15 weeks after surgical decompression. Subjects reported significant improvement among all VAS categories, except for "pulling" (P = 0.14). The change in VAS following surgery was negatively correlated with the pre-surgery VAS for both the summed VAS (r = -0.58, P < 0.001) and the individual VAS scores (all P < 0.01), such that patients who reported the worst symptoms before surgery exhibited relatively greater reductions in symptoms after surgery. This is the first study to suggest improvement in RLS symptoms following surgical decompression of the common and superficial fibular nerves. Further investigation is needed to quantify improvement using RLS-specific metrics and sleep quality assessments.

  19. Restless Legs Syndrome in Patients with Hypertension and Diabetes Mellitus

    PubMed Central

    Sabic, Adela; Sinanovic, Osman; Sabic, Dzevad; Galic, Gordan

    2016-01-01

    Aim: The aim of this study was to analyze frequency of restless legs syndrome (RLS) in patients with hypertension and diabetes mellitus. Patients and Methods: It was analyzed 120 subjects (from Health Center Živinice/Family Medicine Department) through a survey conducted in the period from March to June 2015, of which 30 (8 men/22 women). Subjects were 30 patients with longtime hypertension (HT)(18 men/12 women), 30 patients with diabetes mellitus (DM) type I or II (9 men/21 women), 30 patients with long standing DM type I or II and HT (12 men /18 women), and 30 control subjects (12 men/18 women). RLS were evaluated by questionnaire - International RLS Study Group Criteria. The average age of patients in the group with HT was 58.70 ± 9.07, in the group with DM 48.43 ± 15.37, and in the group of patients with HT and DM 63.90 ± 7.49 years. In the control group mean age was 52.76 ± 14.83 years. Statistical data were analyzed in Excel and SSPS statistical program. Results: RLS was identified in 10 (30%) of those with HT; 7 (21%) in patients with DM, and 10 (30%) in patients with HT+DM. In the control group RLS was verified in 4 (12%) patients. Comparing the results, it was observed significant difference between the HT and the control group (p=0.0012) and HT+ DM and control group (p=0.0012). The frequency of RLS between DM and the control group was not significantly significant (p=0.107). Conclusion: RLS is frequent in patients with hypertension (30%), hypertension+ diabetes mellitus (30%), and patients with DM (21%). PMID:27147785

  20. Silent Cerebral Small Vessel Disease in Restless Legs Syndrome.

    PubMed

    Ferri, Raffaele; Cosentino, Filomena I I; Moussouttas, Michael; Lanuzza, Bartolo; Aricò, Debora; Bagai, Kanika; Wang, Lily; McLaughlin, BethAnn; Walters, Arthur S

    2016-07-01

    Growing literature suggests that patients with restless legs syndrome (RLS) may be at increased risk for hypertension, heart disease, and stroke. Cerebral small vessel disease (SVD) is a known risk factor for clinical stroke. This study evaluated silent cerebral SVD by MRI in patients with RLS, in the absence of a history of previous clinical stroke or known stroke risk factors and taking into account disease duration. Fifty-three patients with RLS < 10 y were prospectively recruited along with 44 with RLS > 10 y and 74 normal controls. A magnetic resonance imaging study was obtained from all subjects and scans were analyzed for area and volume of SVD. There was a significant increase in SVD area in the entire group of RLS patients compared to controls (P = 0.036); this was almost entirely driven by the group with RLS > 10 y. SVD area and volume were significantly increased in patients with RLS > 10 y with respect to both controls (P < 0.0001 and P < 0.0014, respectively) and RLS < 10 y (P < 0.00022 and P < 0.003, respectively). Age, duration of RLS, and the interaction of age and duration of RLS were independent predictors of SVD disease. Duration of RLS was an independent predictor of the burden of cerebral SVD (area P < 0.00012 and volume P < 0.0025), whereas sex and insomnia were not. RLS duration should be taken into account when analyzing the association between RLS and cerebrovascular disease; our data support the hypothesis that a long-lasting RLS and its accompanying periodic limb movements in sleep are a risk factor for silent SVD and perhaps for the development of clinical stroke. © 2016 Associated Professional Sleep Societies, LLC.

  1. [Diagnosis and symptom rating scale of restless legs syndrome].

    PubMed

    Inoue, Yuichi

    2009-05-01

    Restless legs syndrome (RLS) is a sensorimotor disorder, characterized by an irresistible urge to move the legs and usually accompanied or caused by uncomfortable and unpleasant sensations. It begins or worsens during periods of rest or inactivity, is partially or totally relieved by movement and is exacerbated or occurs mainly in the evening or night. People suffering from RLS are estimated to represent 2-3% of the general Japanese population, which is relatively lower than the estimated prevalence in western countries. Supportive diagnostic critevia include family history, the presence of periodic-leg movements (PLM) when awake or asleep, and a positive response to dopaminergic treatment. RLS phenotypes include an early onset form that is usually idiopathic with frequent familial history and a late onset form that is usually secondary to other somatic conditions that are causative factors in RLS occurrence. In all patients presenting with complaints of insomnia or discomfort in the lower limbs, diagnosis of RLS should be considered. RLS should be differentiated from akathisia, which is an urge to move the whole body in the absence of uncomfortable sensations. Polysomnographic studies and the suggested immobilization test (SIT) can detect PLM in patients that are asleep or awake. RLS may cause severe sleep disturbances, poor quality of life, depressive and anxious symptoms, and may be a risk factor for cardiovascular disease. Secondary RLS may occur due to iron deficiency, end-stage renal disease, pregnancy, peripheral neuropathy and drug use including antipsychotics and antidepressants. Small fiber neuropathy can trigger RLS or mimic its symptoms. RLS is associated with many neurological disorders, including Parkinson disease and multiple system atrophy; althoughit does not predispose to these diseases. A symptom rating scale for RLS authorized by the International RLS Study Group (IRLS) would facilitate accurate diagnosis of this condition.

  2. Restless legs syndrome: differential diagnosis and management with pramipexole.

    PubMed

    Brindani, Francesca; Vitetta, Francesca; Gemignani, Franco

    2009-01-01

    Restless legs syndrome (RLS) is a condition characterized by discomfort at rest and urge to move focused on the legs. RLS may occur as an idiopathic, often hereditary condition (primary RLS), or in association with medical conditions (secondary RLS) including iron deficiency, uremia, and polyneuropathy. Current understanding of the pathophysiology of RLS points to the involvement of three interrelated components: dopaminergic dysfunction, impaired iron homeostasis, and genetic mechanisms. The diagnosis of RLS is made according to the consensus criteria by a National Institutes of Health panel: 1) an urge to move the legs, usually accompanied by uncomfortable sensations; 2) beginning or worsening during rest; 3) relieved by movement; and 4) worse, or only occurring, in the evening or at night. The differential diagnosis of RLS aims to: 1) distinguish RLS from other disorders with RLS-like symptoms and 2) identify secondary forms, with investigation of underlying diseases. The treatment of RLS demands a clinical evaluation to rule out and cure causes of secondary RLS, including iron supplementation when deficient, and to eliminate the triggering factors. The presence of neuropathy should be especially investigated in nonhereditary, late-onset RLS, in view of a possible treatment of the underlying disease. The first line treatment for idiopathic RLS is represented by dopamine agonists, in particular nonergot-derived ropinirole and pramipexole, whereas ergot dopamine agonists (cabergoline and pergolide) are no longer in first-line use given the risks of cardiac valvulopathy. Although no comparative trials have been published, a meta-analysis of pramipexole versus ropinirole suggests differences in efficacy and tolerability favoring pramipexole.

  3. Relationship between primary restless legs syndrome and migraine with aura.

    PubMed

    Acar, Bilgehan Atılgan; Acar, Türkan; Alagöz, Aybala Neslihan; Karacan, Alper; Varım, Ceyhun; Uyanık, Mehmet Şevki; Kaya, Tezcan; Akdemir, Ramazan

    2016-08-01

    In this study, the prevalence and characteristics of definite migraine in primary restless legs syndrome (pRLS) patients and matched control patients (CPs) were investigated. We evaluated 63 consecutive adult pRLS patients and 141 age- and sex-matched controls in this case-control study. The diagnosis of migraine and its subtypes were defined based on The International Classification of Headache Disorders-II. Only those with "definite" migraine were included in the study. The mean age of 63 adult pRLS patients (15 men and 48 women) who participated in the study was 49.4 years. A total of 27 patients (42.9%) had definite migraine. Of these migraineurs, seven (11.1%) were without aura and 20 (31.8%) were with aura. The mean age of the 141 matched CPs was 48.7 years. A total of 32 CPs (22.7%) experienced migraine. Among these 32 migraineurs, 28 (19.9%) were without aura and four (2.8%) were with aura. Migraine and migraine with aura were significantly more common in pRLS patients than in CPs. pRLS patients with migraine were more anxious and experienced a shorter duration of RLS symptoms than pRLS patients without migraine. Migraineurs in the pRLS group tended to have high scores for severity of migraine headache by Visual Analog Scale score and high levels of disability by Migraine Disability Assessment grading than those in the control group. pRLS patients showed a positive association with definite migraine headaches. In contrast to results highlighted in recent studies, we found a strong link between migraine with aura and pRLS. Copyright © 2016. Published by Elsevier Taiwan.

  4. Migraine and restless legs syndrome: a systematic review.

    PubMed

    Schürks, Markus; Winter, Anke; Berger, Klaus; Kurth, Tobias

    2014-09-01

    Restless legs syndrome (RLS) is increasingly being reported as a comorbidity of migraine. We conducted a systematic review and meta-analysis of studies investigating RLS in headache/migraine and vice versa. We calculated the prevalence and 95% confidence intervals (CI) of RLS in headache/migraine, of headache/migraine in RLS and controls, and odds ratios (ORs) of the association between the conditions. We then determined pooled effect estimates for the associations. We identified 24 studies. RLS prevalence in migraine ranged from 8.7% to 39.0% with no apparent differences based on gender and aura status. Prevalence among controls was compatible with the literature. Migraine prevalence in RLS ranged from 15.1% to 62.6%. We did not pool prevalence data because of high unexplained heterogeneity. High heterogeneity with respect to the association between any migraine and RLS could be explained by study design. Pooled analyses showed substantially higher effect estimates in case-control studies (pooled OR = 4.19, 95% CI 3.07-5.71; I (2) = 0.0%) than in cohort studies (pooled OR = 1.22, 95% CI 1.14-1.30; I (2) = 0.0%). Our results support the concept of RLS as an important comorbidity of migraine. However, the degree of association appears to be strongly determined by study design. Potential effects by gender and aura status and the role of RLS in other headache disorders remain unclear. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  5. Restless legs syndrome in Wilson's disease: frequency, characteristics, and mimics.

    PubMed

    Trindade, M C; Bittencourt, T; Lorenzi-Filho, G; Alves, R C; de Andrade, D C; Fonoff, E T; Bor-Seng-Shu, E; Machado, A A; Teixeira, M J; Barbosa, E R; Tribl, G G

    2017-02-01

    To determine characteristics, clinical significance, frequency, and mimics of restless legs syndrome (RLS) in a cohort of Wilson's disease (WD, n = 42/f = 18), compared to healthy, matched controls. Structured clinical interviews (patients and caregiving family members), repeated neurological examinations (afternoon and presleep), comprehensive laboratory tests, WD-, RLS-, and sleep-specific rating scales, and video-polysomnography. Thirteen patients with WD (13/42 = 31.0%) clearly fulfilled the five diagnostic criteria of RLS; in eight patients (19.1%), the burden of RLS was clinically significant. The RLS was of moderate severity, equally distributed among sexes, manifested mainly in the evening and before falling asleep, and had developed mostly after clinical manifestation of WD (time elapsed 10.2 ± 14.5 years), still at a young mean age (27.5 ± 11.5 years). The known RLS-associated features were absent (normal iron and kidney parameters) or rare (positive family history, polyneuropathy). Compared to WD patients without RLS, patients with RLS were significantly elder and had suffered longer from WD. WD-specific RLS mimics as well as RLS confounding motor comorbidities (dystonia, tremor, chorea) were frequent and a diagnostic challenge; in difficult cases, the differentiation was reached by clinical observation of the motor behavior in the evening or at nighttime. RLS was frequent in this cohort of WD and might be causally related to WD. RLS should be included in the diagnostic work-up of WD. In complex motor disorders, differential diagnosis of RLS might require evening/nighttime examination and video-polysomnography. In WD patients with a clinically significant RLS, treatment with dopaminergic substances may be considered. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Hyperalgesia and functional sensory loss in restless legs syndrome.

    PubMed

    Stiasny-Kolster, Karin; Pfau, Doreen B; Oertel, Wolfgang H; Treede, Rolf-Detlef; Magerl, Walter

    2013-08-01

    Pain and other sensory signs in patients with restless legs syndrome (RLS) are still poorly understood, as most investigations focus on motor system dysfunctions. This study aimed to investigate somatosensory changes in patients with primary RLS and the restoration of somatosensory function by guideline-based treatment. Forty previously untreated RLS patients were investigated unilaterally over hand and foot using quantitative sensory testing (QST) and were compared with 40 age- and gender-matched healthy subjects. The predominant finding in RLS patients was 3- to 4-fold increase of sensitivity to pinprick stimuli in both extremities (hand: P<.05; foot: P<.001), a sensory pathway involved in withdrawal reflexes. Pinprick hyperalgesia was not paralleled by dynamic mechanical allodynia. Additional significant sensory changes were tactile hypoesthesia in both extremities (hand: P<.05; foot P<.01) and dysesthesia to non-noxious cold stimuli (paradoxical heat sensation), which was present in the foot in an unusually high proportion (14 of 40 patients; P<.01). In 8 patients, follow-up QST 2 to 20 months after treatment with l-DOPA (L-3,4-dihydroxyphenylalanine) revealed a significant reduction of pinprick hyperalgesia (-60%, P<.001), improved tactile detection (+50%, P<.05), and disappearance of paradoxical heat sensation in half of the patients. QST suggested a type of spinal or supraspinal central sensitization differing from neuropathic pain or human experimental models of central sensitization by the absence of dynamic mechanical allodynia. Reversal of pinprick hyperalgesia by l-DOPA may be explained by impaired descending inhibitory dopaminergic control on spinal nociceptive neurons. Restoration of tactile sensitivity and paradoxical heat sensations suggest that they were functional disturbances resulting from central disinhibition.

  7. Crohn's Disease Is Associated With Restless Legs Syndrome

    PubMed Central

    Weinstock, Leonard B.; Bosworth, Brian P.; Scherl, Ellen J.; Li, Ellen; Iroku, Ugonna; Munsell, Melissa A.; Mullen, Gerald E.; Walters, Arthur S.

    2013-01-01

    Extraintestinal manifestations of Crohn's disease (CD) have not previously included the central nervous system (CNS). Restless legs syndrome (RLS) is a CNS disorder that is either idiopathic or secondary to a number of diseases. The aim of this study was to determine if RLS was associated with CD because both are associated with iron deficiency, inflammation, and bacterial overgrowth. Consecutive CD outpatients (N=272) were prospectively surveyed at 4 centers for criteria for RLS. Incidence (having RLS at any point in time), prevalence (having RLS at time of survey), clinical characteristics, risk factors, and potential qualitative relationship between RLS and gastrointestinal symptoms were queried. Incidence of RLS in patients with CD was 42.7%. Prevalence was 30.2% compared with 9% of spouses. Crohn's disease patients with and without RLS had a mean age of 46.8 vs 42.6 years, small intestine involvement in 77.9% vs 66.7%, colon involvement in 39.7% vs 63.2%, and prior iron deficiency anemia in 49.3% vs 33.1%. There was no difference between the CD groups with respect to current iron deficiency, RLS family history, or rare prevalence of concomitant RLS disorders. In 91.8% of patients with RLS and CD, RLS started during or after the onset of CD diagnosis. Among 73 patients with RLS, 67 (44.5%) stated there was a relationship between qualitative RLS symptom improvement with overall CD symptom improvement. These results demonstrate that RLS occurs frequently in CD and appears to be a possible extraintestinal manifestation. The potential relationship of RLS with CD activity warrants further investigation. PMID:19575360

  8. Circadian Change in Blink Reflex Recovery in Restless Legs Syndrome

    PubMed Central

    UZUN, Nurten; GÜNDÜZ, Ayşegül; KARADENİZ, Derya; KIZILTAN, Meral E.

    2016-01-01

    Introduction Restless legs syndrome (RLS) is associated with dysfunction of the dopaminergic systems in the pathways that specifically link the sensory input and motor output. Keeping in mind that clinical symptomatology in RLS and cerebrospinal fluid dopamine concentrations in healthy individuals show changes throughout the day, we hypothesized that excitability of the related pathways increases during the night in RLS, and in the present study, we aimed to analyze our hypothesis by the assessment of blink reflex (BR) recovery. Methods Eleven patients with primary RLS and eight age- and gender-matched healthy subjects were included in the study. All participants underwent detailed interviews and neurological examinations. BR responses were recorded after single and paired supraorbital stimulation during the early afternoon and late at night. For double stimulation, interstimulus intervals (ISI) of 100, 300, and 500 ms were used. Daytime and nighttime investigations were separately compared between the patient and control groups (between-group analyses). In-group analyses were conducted between daytime and nighttime investigations of the patient and control groups. Results BR responses to single stimuli were normal in all participants at all sessions. R2 recovery was the highest in the patient group during nighttime investigations. In-group analysis showed a reduction of R2 recovery during the night in healthy subjects. R2 recoveries at ISIs of 300 and 500 ms at nighttime were higher in RLS patients but did not reach statistical significance. Conclusion The BR circuit is less excitable during the night in healthy individuals, whereas the reduction of excitability is lost in RLS. Despite the limited number of included subjects, we suggest that the normal circadian modulation of the BR circuit is lost in RLS. PMID:28373805

  9. The transcription factor E74-like factor controls quiescence of endothelial cells and their resistance to myeloablative treatments in bone marrow

    USDA-ARS?s Scientific Manuscript database

    The regeneration of the hematopoietic system in bone marrow after chemotherapy depends on a balance between the quiescence and proliferation of lineage-specific progenitor cells. Even though the vascular network in bone is damaged by cytoablation, the transcriptional control of quiescence in endothe...

  10. Reliability, validity, and responsiveness of the Japanese version of International Restless Legs Syndrome Study Group rating scale for restless legs syndrome in a clinical trial setting.

    PubMed

    Inoue, Yuichi; Oka, Yasunori; Kagimura, Tatsuo; Kuroda, Kenji; Hirata, Koichi

    2013-09-01

    This study was conducted to verify the reliability, validity, and responsiveness of the Japanese version of the International Restless Legs Syndrome Study Group Rating Scale for restless legs syndrome (J-IRLS) as a sub-study of a clinical trial of pramipexole against restless legs syndrome. After evaluating the test-retest reliability, concurrent validity and construct validity were analyzed. The responsiveness of J-IRLS was confirmed by evaluating the correlations between the changes in J-IRLS total score after treatment, Clinical Global Impression Improvement Scale (CGI-I), and Patient Global Impression. Test-retest reliability of J-IRLS was good (intra-class correlation coefficient, 0.877; 95% confidence interval, 0.802-0.925). The correlation coefficient of J-IRLS total score and CGI-S score for the first and second visit was 0.804 and 0.796, respectively (both P < 0.0001). Factor analysis of J-IRLS itemsalone identified a two-factor structure. Exploratory analysis on 10 items of J-IRLS together with the Japanese version of the Pittsburgh Sleep Quality Index revealed that several items on the Japanese version of the Pittsburgh Sleep Quality Index appeared as the third factor. The correlations of CGI-I and Patient Global Impression with change in J-IRLS total score after treatment were highly significant. Reliability, validity, and responsiveness of J-IRLS were considered adequate. The scale is highly applicable both for evaluating the severity of restless legs syndrome and for assessing drug efficacy. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

  11. Imbalance between thyroid hormones and the dopaminergic system might be central to the pathophysiology of restless legs syndrome: a hypothesis.

    PubMed

    Pereira, Jose Carlos; Pradella-Hallinan, Marcia; Lins Pessoa, Hugo de

    2010-05-01

    Data collected from medical literature indicate that dopaminergic agonists alleviate Restless Legs Syndrome symptoms while dopaminergic agonists antagonists aggravate them. Dopaminergic agonists is a physiological regulator of thyroid-stimulating hormone. Dopaminergic agonists infusion diminishes the levels of thyroid hormones, which have the ability to provoke restlessness, hyperkinetic states, tremors, and insomnia. Conditions associated with higher levels of thyroid hormones, such as pregnancy or hyperthyroidism, have a higher prevalence of Restless Legs Syndrome symptoms. Low iron levels can cause secondary Restless Legs Syndrome or aggravate symptoms of primary disease as well as diminish enzymatic activities that are involved in dopaminergic agonists production and the degradation of thyroid hormones. Moreover, as a result of low iron levels, dopaminergic agonists diminishes and thyroid hormones increase. Iron therapy improves Restless Legs Syndrome symptoms in iron deprived patients. Medical hypothesis. To discuss the theory that thyroid hormones, when not counterbalanced by dopaminergic agonists, may precipitate the signs and symptoms underpinning Restless Legs Syndrome. The main cause of Restless Legs Syndrome might be an imbalance between the dopaminergic agonists system and thyroid hormones.

  12. Failure of a Neutrino-driven Explosion after Core-collapse May Lead to a Thermonuclear Supernova

    NASA Astrophysics Data System (ADS)

    Kushnir, Doron; Katz, Boaz

    2015-10-01

    We demonstrate that ∼10 s after the core-collapse of a massive star, a thermonuclear explosion of the outer shells is possible for some (tuned) initial density and composition profiles, assuming that the neutrinos failed to explode the star. The explosion may lead to a successful supernova, as first suggested by Burbidge et al. We perform a series of one-dimensional (1D) calculations of collapsing massive stars with simplified initial density profiles (similar to the results of stellar evolution calculations) and various compositions (not similar to 1D stellar evolution calculations). We assume that the neutrinos escaped with a negligible effect on the outer layers, which inevitably collapse. As the shells collapse, they compress and heat up adiabatically, enhancing the rate of thermonuclear burning. In some cases, where significant shells of mixed helium and oxygen are present with pre-collapsed burning times of ≲100 s (≈10 times the free-fall time), a thermonuclear detonation wave is ignited, which unbinds the outer layers of the star, leading to a supernova. The energy released is small, ≲1050 erg, and negligible amounts of synthesized material (including 56Ni) are ejected, implying that these 1D simulations are unlikely to represent typical core-collapse supernovae. However, they do serve as a proof of concept that the core-collapse-induced thermonuclear explosions are possible, and more realistic two-dimensional and three-dimensional simulations are within current computational capabilities.

  13. APPLICATIONS OF LASERS AND OTHER TOPICS IN LASER PHYSICS AND TECHNOLOGY: Hybrid reactor based on laser thermonuclear fusion

    NASA Astrophysics Data System (ADS)

    Basov, N. G.; Belousov, N. I.; Grishunin, P. A.; Kalmykov, Yu K.; Lebo, I. G.; Rozanov, Vladislav B.; Sklizkov, G. V.; Subbotin, V. I.; Finkel'shteĭn, K. I.; Kharitonov, V. V.; Sherstnev, K. B.

    1987-10-01

    A physicotechnical and parametric analysis is used as the basis for a conceptual design of a thermonuclear inertial-confinement hybrid reactor as a breeder of fuel for fission nuclear power stations. It is proposed to use a laser as a driver in this reactor.

  14. Spreading of thermonuclear flames on the neutron star in SAX J1808.4-3658: an observational tool

    NASA Technical Reports Server (NTRS)

    Bhattacharyya, Sudip; Strohmayer, Tod E.

    2005-01-01

    We analyse archival Rossi X-Ray Timing Explorer (RXTE) proportional counter array (PCA) data of thermonuclear X-ray bursts from the 2002 outburst of the accreting millisecond pulsar SAX 51808.4-3658. We present evidence of a complex frequency modulation of oscillations during burst rise, and correlations among the time evolution of the oscillation frequency, amplitude, and the inferred burning region area. We discuss these findings in the context of a model, based on thermonuclear flame spreading on the neutron star surface, that can qualitatively explain these features. From our model, we infer that for the 2002 Oct. 15 thermonuclear burst, the ignition likely occurred in the mid-latitudes, the burning region took approx. 0.2 s to nearly encircle the equatorial region of the neutron star, and after that the lower amplitude oscillation originated from the remaining asymmetry of the burning front in the same hemisphere where the burst ignited. We emphasize that studies of the evolution of burst oscillation properties during burst rise can provide a powerful tool to understand thermonuclear flame spreading on neutron star surfaces under extreme physical conditions.

  15. FAILURE OF A NEUTRINO-DRIVEN EXPLOSION AFTER CORE-COLLAPSE MAY LEAD TO A THERMONUCLEAR SUPERNOVA

    SciTech Connect

    Kushnir, Doron; Katz, Boaz

    2015-10-01

    We demonstrate that ∼10 s after the core-collapse of a massive star, a thermonuclear explosion of the outer shells is possible for some (tuned) initial density and composition profiles, assuming that the neutrinos failed to explode the star. The explosion may lead to a successful supernova, as first suggested by Burbidge et al. We perform a series of one-dimensional (1D) calculations of collapsing massive stars with simplified initial density profiles (similar to the results of stellar evolution calculations) and various compositions (not similar to 1D stellar evolution calculations). We assume that the neutrinos escaped with a negligible effect on the outer layers, which inevitably collapse. As the shells collapse, they compress and heat up adiabatically, enhancing the rate of thermonuclear burning. In some cases, where significant shells of mixed helium and oxygen are present with pre-collapsed burning times of ≲100 s (≈10 times the free-fall time), a thermonuclear detonation wave is ignited, which unbinds the outer layers of the star, leading to a supernova. The energy released is small, ≲10{sup 50} erg, and negligible amounts of synthesized material (including {sup 56}Ni) are ejected, implying that these 1D simulations are unlikely to represent typical core-collapse supernovae. However, they do serve as a proof of concept that the core-collapse-induced thermonuclear explosions are possible, and more realistic two-dimensional and three-dimensional simulations are within current computational capabilities.

  16. EFFECT OF LASER LIGHT ON MATTER. LASER PLASMAS: Films containing heavy hydrogen isotopes in laser thermonuclear fusion targets

    NASA Astrophysics Data System (ADS)

    Abramov, Yu A.; Bessarab, A. V.; Veselov, A. V.; Gavrilov, P. I.; Druzhinin, A. A.; Izgorodin, V. M.; Karel'skaya, T. V.; Kirillov, G. A.; Komleva, G. V.; Lyamin, G. A.; Nikolaev, G. P.; Pinegin, A. V.; Punin, V. T.; Rabinovich, K. G.; Romaev, V. N.; Rogachev, V. G.; Solomatina, E. Yu; Tarasova, N. N.; Tachaev, G. V.; Andryushin, V. V.; Emel'yanov, S. A.; Kryuchenkov, V. B.; Markelov, N. N.; Markushkin, Yu E.; Chirin, N. A.

    1994-02-01

    An investigation was made of fuel films in targets used in experiments on laser thermonuclear fusion in Iskra-4 and Iskra-5 systems. These films were formed from condensed deuterium and a deuterium—tritium mixture, and also from metal hydrides and polyethylene containing deuterium and tritium.

  17. Stellar dynamics. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova.

    PubMed

    Geier, S; Fürst, F; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C

    2015-03-06

    Hypervelocity stars (HVSs) travel with velocities so high that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US 708. Traveling with a velocity of ~1200 kilometers per second, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVSs. Furthermore, we detected that US 708 is a fast rotator. According to our binary evolution model, it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova. Copyright © 2015, American Association for the Advancement of Science.

  18. Simulations of alpha particle ripple loss from the International Thermonuclear Experimental Reactor

    SciTech Connect

    Redi, M.H.; Budny, R.V.; McCune, D.C.; Miller, C.O.; White, R.B.

    1996-05-01

    Calculations of collisional stochastic ripple loss of alpha particles from the new 20 toroidal field (TF) coil International Thermonuclear Experimental Reactor (ITER) predict small alpha ripple losses, less than 0.4%, close to the loss calculated for the full current operation of the earlier 24 TF coil design. An analytic fit is obtained to the ITER ripple data field demonstrating the nonlinear height dependence of the ripple minimum for D shaped ripple contours. In contrast to alpha loss simulations for the Tokamak Fusion Test Reactor (TFTR), a simple Goldston, White, Boozer stochastic loss criterion ripple loss model is found to require an increased renormalization of the stochastic threshold {delta}{sub s}/{delta}{sub GWB} {ge} 1. Effects of collisions, sawtooth broadening and reversal of the grad B drift direction are included in the particle following simulations.

  19. Plasma physics effects on thermonuclear burn rate in the presence of hydrodynamic mix

    NASA Astrophysics Data System (ADS)

    Tang, Xian-Zhu; Guo, Zehua; Kagan, Grigory; McDevitt, Christopher; Srinivasan, Bhuvana

    2016-03-01

    Hydrodynamic mix can significantly degrade thermonuclear burn rate in an inertial confinement fusion (ICF) target. Successful mitigation requires a detailed understanding of the physical mechanisms by which mix affects burn. Here we summarize the roles of three distinct plasma physics effects on burn rate. The first is the well-known effect of enhanced thermal energy loss from the hot spot and the mitigating role of self-generated or externally-applied magnetic field. The second is the fuel ion separation via inter-species ion diffusion driven by the powerful thermodynamic forces exacerbated by mix during the implosion process. The third is the fusion reactivity modification by fast ion transport in a mix-dominated ICF target, where hot plasma is intermingled with cold fuel.

  20. Masses And Radii Of Neutron Stars Measured From Thermonuclear X-ray Bursts

    NASA Astrophysics Data System (ADS)

    Guver, Tolga; Ozel, F.

    2011-09-01

    Low mass X-ray binaries that show thermonuclear bursts are ideal targets for constraining the equation of state of neutron star matter. The analysis of the time resolved, high count rate X-ray spectra allow a measurement of the Eddington limits and the apparent radii of neutron stars. Combined with an independent distance estimate, these spectroscopic quantities lead to the measurement of neutron star masses and radii. I will discuss the results of the application of this method to a number of X-ray binaries including EXO 1745-248, 4U 1820-30, 4U 1608-52,KS 1731-260, and SAX J1748.9-2021. I will also present the results from a comprehensive analysis of the entire RXTE archive of X-ray burst observations, which allows for a better quantification of the systematic uncertainties in these measurements.

  1. Diffuse Galactic antimatter from faint thermonuclear supernovae in old stellar populations

    NASA Astrophysics Data System (ADS)

    Crocker, Roland M.; Ruiter, Ashley J.; Seitenzahl, Ivo R.; Panther, Fiona H.; Sim, Stuart; Baumgardt, Holger; Möller, Anais; Nataf, David M.; Ferrario, Lilia; Eldridge, J. J.; White, Martin; Tucker, Brad E.; Aharonian, Felix

    2017-06-01

    Our Galaxy hosts the annihilation of a few 1043 low-energy positrons every second. Radioactive isotopes capable of supplying such positrons are synthesized in stars, stellar remnants and supernovae. For decades, however, there has been no positive identification of a main stellar positron source, leading to suggestions that many positrons originate from exotic sources like the Galaxy's central supermassive black hole or dark matter annihilation. Here we show that a single type of transient source, deriving from stellar populations of age 3-6 Gyr and yielding ∼0.03 M ⊙ of the positron emitter 44Ti, can simultaneously explain the strength and morphology of the Galactic positron annihilation signal and the Solar System abundance of the 44Ti decay product 44Ca. This transient is likely the merger of two low-mass white dwarfs, observed in external galaxies as the sub-luminous, thermonuclear supernova known as SN 1991bg-like.

  2. Astrophysics Simulations from the ASC/Alliances Center for Astrophysical Thermonuclear Flashes

    DOE Data Explorer

    The "Flash Center" works to solve the long-standing problem of thermonuclear flashes on the surfaces of compact stars such as neutron stars and white dwarfs, and in the interior of white dwarfs (i.e., Type I supernovae). The physical conditions, and many of the physical phenomena, are similar to those confronted by the Department of Energy Stockpile Stewardship program. The (fully ionized) plasmas are at very high temperatures and densities; and the physical problems of nuclear ignition, deflagration or detonation, turbulent mixing, and interface dynamics for complex multicomponent fluids are common to the weapons program. Because virtually every aspect of this problem represents a computational Grand Challenge, large-scale numerical simulations are at the heart of its resolution (Taken from Executive Summary page). More than 35 simulations and computer animations developed through research at the "Flash Center" are available here. The collection offers .avi, .flv, or .mpeg file downloads as well as references to related research papers or presentations.

  3. ITER (International Thermonuclear Experimental Reactor) shield and blanket work package report

    SciTech Connect

    Not Available

    1988-06-01

    This report summarizes nuclear-related work in support of the US effort for the International Thermonuclear Experimental Reactor (ITER) Study. The purpose of this work was to prepare for the first international ITER workshop devoted to defining a basic ITER concept that will serve as a basis for an indepth conceptual design activity over the next 2-1/2 years. Primary tasks carried out during the past year included: design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components and issues regarding structural materials for an ITER device. 44 refs., 31 figs., 29 tabs.

  4. The effect of relativistic Compton scattering on thermonuclear burn of pure deuterium fuel

    SciTech Connect

    Ghasemizad, A.; Nazirzadeh, M.; Khanbabaei, B.

    2016-08-15

    The relativistic effects of the Compton scattering on the thermonuclear burn-up of pure deuterium fuel in non-equilibrium plasma have been studied by four temperature (4T) theory. In the limit of low electron temperatures and photon energies, the nonrelativistic Compton scattering is valid and a convenient approximation, but in the high energy exchange rates between electrons and photons, is seen to break down. The deficiencies of the nonrelativistic approximation can be overcome by using the relativistic correction in the photons kinetic equation. In this research, we have utilized the four temperature (4T) theory to calculate the critical burn-up parameter for pure deuterium fuel, while the Compton scattering is considered as a relativistic phenomenon. It was shown that the measured critical burn-up parameter in ignition with relativistic Compton scattering is smaller than that of the parameter in the ignition with the nonrelativistic Compton scattering.

  5. The development of beryllium plasma spray technology for the International Thermonuclear Experimental Reactor (ITER)

    SciTech Connect

    Castro, R.G.; Elliott, K.E.; Hollis, K.J.; Bartlett, A.H.; Watson, R.D.

    1999-02-01

    Over the past five years, four international parties, which include the European Communities, Japan, the Russian Federation and the United States, have been collaborating on the design and development of the International Thermonuclear Experimental Reactor (ITER), the next generation magnetic fusion energy device. During the ITER Engineering Design Activity (EDA), beryllium plasma spray technology was investigated by Los Alamos National Laboratory as a method for fabricating and repairing and the beryllium first wall surface of the ITER tokamak. Significant progress has been made in developing beryllium plasma spraying technology for this application. Information will be presented on the research performed to improve the thermal properties of plasma sprayed beryllium coatings and a method that was developed for cleaning and preparing the surface of beryllium prior to depositing plasma sprayed beryllium coatings. Results of high heat flux testing of the beryllium coatings using electron beam simulated ITER conditions will also be presented.

  6. Mirror test for International Thermonuclear Experimental Reactor at the JET tokamak: An overview of the program

    NASA Astrophysics Data System (ADS)

    Rubel, M. J.; De Temmerman, G.; Coad, J. P.; Vince, J.; Drake, J. R.; Le Guern, F.; Murari, A.; Pitts, R. A.; Walker, C.; JET-EFDA Contributors

    2006-06-01

    Metallic mirrors will be essential components of all optical spectroscopy and imaging systems for plasma diagnosis that will be used at the next-step magnetic fusion experiment, International Thermonuclear Experimental Reactor (ITER). Any change of the mirror performance, in particular, reflectivity, will influence the quality and reliability of detected signals. At the instigation of the ITER Design Team, a dedicated technical and experimental activity aiming at the assessment of mirror surface degradation as a result of exposure to the plasma has been initiated on the JET tokamak. This article provides a comprehensive overview of the mirror test program, including design details of the mirror samples and their supports, their locations within JET, and the issue of optical characterization of the mirrors both before and after exposure. The postexposure characterization is particularly challenging in JET as a consequence of an environment in which both tritium and beryllium are present.

  7. Review of the International Thermonuclear Experimental Reactor (ITER) detailed design report

    SciTech Connect

    1997-04-18

    Dr. Martha Krebs, Director, Office of Energy Research at the US Department of Energy (DOE), wrote to the Fusion Energy Sciences Advisory Committee (FESAC), in letters dated September 23 and November 6, 1996, requesting that FESAC review the International Thermonuclear Experimental Reactor (ITER) Detailed Design Report (DDR) and provide its view of the adequacy of the DDR as part of the basis for the United States decision to enter negotiations with the other interested Parties regarding the terms and conditions for an agreement for the construction, operations, exploitation and decommissioning of ITER. The letter from Dr. Krebs, referred to as the Charge Letter, provided context for the review and a set of questions of specific interest.

  8. The development and the tests of the electrostatic probe for dust particle collection in thermonuclear reactors

    NASA Astrophysics Data System (ADS)

    Begrambekov, L. B.; Voityuk, A. N.; Zakharov, A. M.

    2016-09-01

    Formation of dust particles in thermonuclear reactors can greatly affect the plasma parameters and lead to accumulation of tritium. The rates of formation and deposition of dust need to be measured, and the parameters of formation of dust particles and clusters need to be studied. A model of a device for collection of fine conductive particles capable of removing them from the reactor chamber for future research is proposed in this paper. The dust collector's operation is based on a principle of applied electrostatic field. The model was tested in different operating conditions: in vacuum, at the atmospheric pressure in the atmosphere of air and dry nitrogen. The experiments were conducted with a stationary system and with the dust collector in motion relative to the dusty surface. It is shown that, during the probe moving relative to the surface, it can remove up to 95% of fine tungsten particles with sizes ranging from 1 to 10 μm.

  9. SPIRAL INSTABILITY CAN DRIVE THERMONUCLEAR EXPLOSIONS IN BINARY WHITE DWARF MERGERS

    SciTech Connect

    Kashyap, Rahul; Fisher, Robert; García-Berro, Enrique; Aznar-Siguán, Gabriela; Lorén-Aguilar, Pablo

    2015-02-10

    Thermonuclear, or Type Ia supernovae (SNe Ia), originate from the explosion of carbon–oxygen white dwarfs, and serve as standardizable cosmological candles. However, despite their importance, the nature of the progenitor systems that give rise to SNe Ia has not been hitherto elucidated. Observational evidence favors the double-degenerate channel in which merging white dwarf binaries lead to SNe Ia. Furthermore, significant discrepancies exist between observations and theory, and to date, there has been no self-consistent merger model that yields a SNe Ia. Here we show that a spiral mode instability in the accretion disk formed during a binary white dwarf merger leads to a detonation on a dynamical timescale. This mechanism sheds light on how white dwarf mergers may frequently yield SNe Ia.

  10. Annual report of the Summit Members' Working Group on Controlled Thermonuclear Fusion (Fusin Working Group (FWG))

    SciTech Connect

    none,

    1987-04-01

    The Summit Members' Working Group on Controlled Thermonuclear Fusion (Fusion Working Group (FWG)) was established in 1983 in response to the Declaration of the Heads of State and Government at the Versailles Economic Summit meeting of 1982, and in response to the subsequent report of the Working Group in Technology, Growth and Employment (TGE) as endorsed at the Williamsburg Summit meeting, 1983. This document contains the complete written record of each of the three FWG meetings which include the minutes, lists of attendees, agendas, statements, and summary conclusions as well as the full reports of the Technical Working Party. In addition, there is a pertinent exchange of correspondence between FWG members on the role of the Technical Working Party and a requested background paper on the modalities associated with a possible future ETR project.

  11. The Influence of Accretion Rate and Metallicity on Thermonuclear Bursts: Predictions from KEPLER Models

    NASA Astrophysics Data System (ADS)

    Lampe, Nathanael; Heger, Alexander; Galloway, Duncan K.

    2016-03-01

    Using the KEPLER hydrodynamics code, 464 models of thermonuclear X-ray bursters were performed across a range of accretion rates and compositions. We present the library of simulated burst profiles from this sample, and examine variations in the simulated light curve for different model conditions. We find that the recurrence time varies as a power law against accretion rate, and measure its slope while mixed H/He burning is occurring for a range of metallicities, finding the power law gradient to vary from η =1.1 to 1.24. We identify the accretion rates at which mixed H/He burning stops and a transition occurs to different burning regimes. We explore how varying the accretion rate and metallicity affects burst morphology in both the rise and tail.

  12. VizieR Online Data Catalog: Models of thermonuclear X-ray bursters (Lampe+, 2016)

    NASA Astrophysics Data System (ADS)

    Lampe, N.; Heger, A.; Galloway, D. K.

    2016-05-01

    Using the KEPLER 1D hydrodynamics code (Woosley et al. 2004ApJS..151...75W), 464 models of thermonuclear X-ray bursters were performed across a range of accretion rates and compositions. We present the library of simulated burst profiles from this sample, and examine variations in the simulated light curve for different model conditions. We find that the recurrence time varies as a power law against accretion rate, and measure its slope while mixed H/He burning is occurring for a range of metallicities, finding the power law gradient to vary from {eta}=1.1 to 1.24. We identify the accretion rates at which mixed H/He burning stops and a transition occurs to different burning regimes. We explore how varying the accretion rate and metallicity affects burst morphology in both the rise and tail. (1 data file).

  13. Restless mind, restless body.

    PubMed

    Seli, Paul; Carriere, Jonathan S A; Thomson, David R; Cheyne, James Allan; Martens, Kaylena A Ehgoetz; Smilek, Daniel

    2014-05-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which required them to synchronize button presses with tones. Participants performed this task while sitting on a Wii Balance Board providing us with an index of fidgeting. Results of Study 1 demonstrate that relative to on-task periods, mind wandering is indeed accompanied by increases in fidgeting, as well as increased response variability in the MRT. In Study 2, we observed that only deep mind wandering was associated with increases in fidgeting, whereas task-related response variability increased even during mild mind wandering. We interpret these findings in the context of current theories of mind wandering and suggest that (a) mind wandering is associated with costs not only to primary-task performance but also to secondary-task goals (e.g., controlling extraneous movements) and (b) these costs may depend on the degree to which task-related executive control processes are disengaged during mind wandering (i.e., depth of mind wandering).

  14. Restless Mind, Restless Body

    ERIC Educational Resources Information Center

    Seli, Paul; Carriere, Jonathan S. A.; Thomson, David R.; Cheyne, James Allan; Martens, Kaylena A. Ehgoetz; Smilek, Daniel

    2014-01-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which…

  15. Restless Mind, Restless Body

    ERIC Educational Resources Information Center

    Seli, Paul; Carriere, Jonathan S. A.; Thomson, David R.; Cheyne, James Allan; Martens, Kaylena A. Ehgoetz; Smilek, Daniel

    2014-01-01

    In the present work, we investigate the hypothesis that failures of task-related executive control that occur during episodes of mind wandering are associated with an increase in extraneous movements (fidgeting). In 2 studies, we assessed mind wandering using thought probes while participants performed the metronome response task (MRT), which…

  16. Diagnosis and treatment of restless legs syndrome in progressive supranuclear palsy.

    PubMed

    Moccia, Marcello; Picillo, Marina; Erro, Roberto; Allocca, Roberto; Barone, Paolo; Vitale, Carmine

    2015-03-15

    Restless legs syndrome (RLS) has only been recently investigated in a small cohort of progressive supranuclear palsy (PSP) patients and it has been reported to have variable prevalence (among 3.7-58%). However little is known about its management. Here, we report a case of severe RLS occurring during the course of PSP. Diagnostic issues and therapeutic approaches are discussed.

  17. Migratory restlessness in captive individuals predicts actual departure in the wild

    PubMed Central

    Eikenaar, Cas; Klinner, Thomas; Szostek, K. Lesley; Bairlein, Franz

    2014-01-01

    In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such ‘migratory restlessness’ has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific traits. These studies thus assumed that, also at the level of the individual, migratory restlessness is an accurate proxy for the motivation to migrate. We tested this assumption for the first time and found that it holds; individuals showing very little migratory restlessness remained at stopover for longer than one night, whereas most individuals showing more restlessness departed sooner. This finding validates the use of migratory restlessness as a proxy for the motivation to migrate, thereby justifying the conclusions made in a large body of research on avian migration. PMID:24718095

  18. Seasonal trends in restless legs symptomatology: evidence from Internet search query data.

    PubMed

    Ingram, David G; Plante, David T

    2013-12-01

    Patients with Willis-Ekbom disease (restless legs syndrome [RLS]) frequently report seasonal worsening of their symptoms; however, seasonal patterns in this disorder have not been systematically evaluated. The purpose of our investigation was to utilize Internet search query data to test the hypothesis that restless legs symptoms vary by season, with worsening in the summer months. Internet search query data were obtained from Google Trends. Monthly normalized search volume was determined for the term restless legs between January 2004 and December 2012. Using cosinor analysis, seasonal effects were tested for data from the United States, Australia, Germany, the United Kingdom, and Canada. Cosinor analysis revealed statistically significant seasonal effects on search queries in the United States (P=.005), Australia (P=.00007), Germany (P=.00009), and the United Kingdom (P=.003), though a trend was present in the search data from Canada (P=.098). Search queries peaked in summer months in both northern (June and July) and southern (January) hemispheres. Search query volume increased by 24-40% during summer relative to winter months across all evaluated countries. Evidence from Internet search queries across a wide range of dates and geographic areas suggested a seasonality of restless legs symptomatology with a peak in summer months. Our novel finding in RLS epidemiology needs to be confirmed in additional samples, and underlying mechanisms must be elucidated. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. [Rest-activity rhythm, sleep pattern and quality of life in patients with restless legs syndrome].

    PubMed

    Lee, Eun Ju

    2009-06-01

    In this study rest-activity rhythm, sleep pattern and quality of life of patients with restless legs syndrome were compared with those of a normal group. The participants in this study were 36 patients with restless legs syndrome diagnosed by a neurologist and 36 participants in the normal group. An actigraph, sleep diary, Pittsburgh Sleep Quality Index and Insomnia Severity Index scale were used as measurement tools for the study. Chi-square test, Lamda test, t-test and Kendall's correlation with SPSS 12.0 program were used to analyze the data. Patients with restless legs syndrome had a higher rest-activity rhythm curve of Least 5 hr's activity (L5) and Most 10 hr's activity (M10) than those of normal group and sleep problems included decreased sleep efficiency and increased sleep latency, wake time and number of awakenings. The scores for the subscales of quality of life in patients with restless legs syndrome were lower than the normal group for general health, physical functioning, role limitations due to emotional problems, role limitation due to physical problems, social functioning, bodily pain, vitality and mental health. The results suggest that further studies are needed to identify rest-activity rhythm according to symptom severity and to develop nursing interventions which consider rest-activity rhythm.

  20. Restless legs syndrome and sleep disturbance during pregnancy: the role of folate and iron.

    PubMed

    Lee, K A; Zaffke, M E; Baratte-Beebe, K

    2001-05-01

    Restless legs syndrome (RLS) is a neurosensory disorder that typically begins in the evening and often prevents a person from falling asleep. It has been associated with iron deficiency anemia and dopaminergic pathways and is often treated with iron infusion or dopamine agonists. The purpose of this secondary analysis of longitudinal data collected on women before, during, and after pregnancy is to document the prevalence of RLS during pregnancy, contrast its effect on sleep and mood state, and explore the role of folate and iron in the expression of RLS, specifically during the third trimester when the syndrome is most distressing. The prevalence increased from 0 during preconception to 23% (n = 7) during the third trimester of pregnancy. Only 1 subject continued to experience RLS after delivery. Compared with those without complaints of restless legs, those with restless legs had low serum ferritin at preconception and significantly lower folate levels during preconception and at each trimester. In addition, time to sleep onset was significantly delayed and depressed mood was significantly higher in the RLS group. Rather than indicators of iron deficiency anemia (serum ferritin, serum iron, and hemoglobin) or pernicious anemia (vitamin B(12)), it was reduced serum folate level that was associated with RLS in this sample of pregnant women. Findings indicate a need to reconsider recommendations about the normal ranges of serum ferritin and serum folate levels during pregnancy to minimize the complaints of restless legs and promote more consolidated sleep and better daytime mood state during pregnancy.

  1. The internal restlessness scale: performance of college students with and without ADHD.

    PubMed

    Weyandt, Lisa L; Iwaszuk, Wendy; Fulton, Katie; Ollerton, Micha; Beatty, Noelle; Fouts, Hillary; Schepman, Stephen; Greenlaw, Corey

    2003-01-01

    Attention-deficit/hyperactivity disorder (ADHD) was previously believed to be a disorder of childhood, with symptoms attenuating at the onset of puberty. Follow-up studies, however, suggest that the majority of children with ADHD continue to manifest symptoms into adulthood. Although the inattention components associated with ADHD persist into adulthood, the nature of the hyperactivity component is less well understood. For example, according to criteria established by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, hyperactivity in adolescents and adults may be limited to subjective feelings of restlessness. Recent studies with adults with ADHD have also reported that mental restlessness is commonly reported by individuals with the disorder. To better understand this characteristic of ADHD, the Internal Restlessness Scale (IRS) was developed. The results of the IRS suggest that (a) college students with ADHD report significantly higher ratings of internal restlessness than college students without ADHD, and (b) the IRS appears to have adequate test-retest reliability and a four-factor structure. Implications and suggestions for future research are discussed.

  2. RELATIVISTIC COLLAPSE AND EXPLOSION OF ROTATING SUPERMASSIVE STARS WITH THERMONUCLEAR EFFECTS

    SciTech Connect

    Montero, Pedro J.; Janka, Hans-Thomas; Mueller, Ewald

    2012-04-10

    We present results of general relativistic simulations of collapsing supermassive stars with and without rotation using the two-dimensional general relativistic numerical code Nada, which solves the Einstein equations written in the BSSN formalism and the general relativistic hydrodynamic equations with high-resolution shock-capturing schemes. These numerical simulations use an equation of state that includes the effects of gas pressure and, in a tabulated form, those associated with radiation and the electron-positron pairs. We also take into account the effect of thermonuclear energy released by hydrogen and helium burning. We find that objects with a mass of Almost-Equal-To 5 Multiplication-Sign 10{sup 5} M{sub Sun} and an initial metallicity greater than Z{sub CNO} Almost-Equal-To 0.007 do explode if non-rotating, while the threshold metallicity for an explosion is reduced to Z{sub CNO} Almost-Equal-To 0.001 for objects uniformly rotating. The critical initial metallicity for a thermonuclear explosion increases for stars with a mass Almost-Equal-To 10{sup 6} M{sub Sun }. For those stars that do not explode, we follow the evolution beyond the phase of black hole (BH) formation. We compute the neutrino energy loss rates due to several processes that may be relevant during the gravitational collapse of these objects. The peak luminosities of neutrinos and antineutrinos of all flavors for models collapsing to a BH are L{sub {nu}} {approx} 10{sup 55} erg s{sup -1}. The total radiated energy in neutrinos varies between E{sub {nu}} {approx} 10{sup 56} erg for models collapsing to a BH and E{sub {nu}} {approx} 10{sup 45}-10{sup 46} erg for models exploding.

  3. Use of liquid metals in nuclear and thermonuclear engineering, and in other innovative technologies

    NASA Astrophysics Data System (ADS)

    Rachkov, V. I.; Arnol'dov, M. N.; Efanov, A. D.; Kalyakin, S. G.; Kozlov, F. A.; Loginov, N. I.; Orlov, Yu. I.; Sorokin, A. P.

    2014-05-01

    By now, a good deal of experience has been gained with using liquid metals as coolants in nuclear power installations; extensive knowledge has been gained about the physical, thermophysical, and physicochemical properties of these coolants; and the scientific principles and a set of methods and means for handling liquid metals as coolants for nuclear power installations have been elaborated. Prototype and commercialgrade sodium-cooled NPP power units have been developed, including the BOR-60, BN-350, and BN-600 power units (the Soviet Union); the Rapsodie, Phenix, and Superphenix power units (France), the EBR-II power unit (the United States); and the PFR power unit (the United Kingdom). In Russia, dedicated nuclear power installations have been constructed, including those with a lead-bismuth coolant for nuclear submarines and with sodium-potassium alloy for spacecraft (the Buk and Topol installations), which have no analogs around the world. Liquid metals (primarily lithium and its alloy with lead) hold promise for use in thermonuclear power engineering, where they can serve not only as a coolant, but also as tritium-producing medium. In this article, the physicochemical properties of liquid metal coolants, as well as practical experience gained from using them in nuclear and thermonuclear power engineering and in innovative technologies are considered, and the lines of further research works are formulated. New results obtained from investigations carried out on the Pb-Bi and Pb for the SVBR and BREST fast-neutron reactors (referred to henceforth as fast reactors) and for controlled accelerator systems are described.

  4. Relativistic Collapse and Explosion of Rotating Supermassive Stars with Thermonuclear Effects

    NASA Astrophysics Data System (ADS)

    Montero, Pedro J.; Janka, Hans-Thomas; Müller, Ewald

    2012-04-01

    We present results of general relativistic simulations of collapsing supermassive stars with and without rotation using the two-dimensional general relativistic numerical code Nada, which solves the Einstein equations written in the BSSN formalism and the general relativistic hydrodynamic equations with high-resolution shock-capturing schemes. These numerical simulations use an equation of state that includes the effects of gas pressure and, in a tabulated form, those associated with radiation and the electron-positron pairs. We also take into account the effect of thermonuclear energy released by hydrogen and helium burning. We find that objects with a mass of ≈5 × 105 M ⊙ and an initial metallicity greater than Z CNO ≈ 0.007 do explode if non-rotating, while the threshold metallicity for an explosion is reduced to Z CNO ≈ 0.001 for objects uniformly rotating. The critical initial metallicity for a thermonuclear explosion increases for stars with a mass ≈106 M ⊙. For those stars that do not explode, we follow the evolution beyond the phase of black hole (BH) formation. We compute the neutrino energy loss rates due to several processes that may be relevant during the gravitational collapse of these objects. The peak luminosities of neutrinos and antineutrinos of all flavors for models collapsing to a BH are L ν ~ 1055 erg s-1. The total radiated energy in neutrinos varies between E ν ~ 1056 erg for models collapsing to a BH and E ν ~ 1045-1046 erg for models exploding.

  5. A burst from a thermonuclear runaway on an ONeMg white dwarf

    NASA Technical Reports Server (NTRS)

    Starrfield, S.; Politano, M.; Truran, J. W.; Sparks, W. M.

    1992-01-01

    Studies which examine the consequences of accretion, at rates of 10(exp -9) solar mass/yr and 10(exp -10) solar mass/yr, onto an ONeMg white dwarf with a mass of 1.35 solar masses are performed. In these studies, a Lagrangian, hydrodynamic, one-dimensional computer code was used. The code now includes a network with 89 nuclei up to Ca-40, elemental diffusion, new opacities, and new equation of state. The initial abundance distribution corresponded to a mixture that was enriched to either 25, 50, or 75 percent in products of carbon burning. The remaining material in each case is assumed to have a solar composition. The evolution of the thermonuclear runaway in the 1.35 solar mass white dwarf, with M = 10(exp -9) solar mass, produced peak temperatures in the shell source exceeding 300 million degrees. The sequence produced significant amounts of Na-22 from proton captures onto Ne-20 and significant amounts of Al-26 from proton captures on Mg-24. This sequence ejected 5.2 x 10(exp -6) solar mass moving with speeds from approximately 100 km/s to 2300 km/s. When the mass accretion rate was decreased to 10(exp -10) solar mass, the resulting thermonuclear runaway produced a shock that moved through the outer envelope of the white dwarf and raised the surface luminosity to L greater than 10(exp 7) solar luminosity and the effective temperature to values exceeding 10(exp 7) K. The interaction of the material expanding from off of the white dwarf with the accretion disk should produce a burst of gamma-rays.

  6. A burst from a thermonuclear runaway on an ONeMg white dwarf

    NASA Astrophysics Data System (ADS)

    Starrfield, S.; Politano, M.; Truran, J. W.; Sparks, W. M.

    1992-02-01

    Studies which examine the consequences of accretion, at rates of 10-9 solar mass/yr and 10-10 solar mass/yr, onto an ONeMg white dwarf with a mass of 1.35 solar masses are performed. In these studies, a Lagrangian, hydrodynamic, one-dimensional computer code was used. The code now includes a network with 89 nuclei up to Ca-40, elemental diffusion, new opacities, and new equation of state. The initial abundance distribution corresponded to a mixture that was enriched to either 25, 50, or 75 percent in products of carbon burning. The remaining material in each case is assumed to have a solar composition. The evolution of the thermonuclear runaway in the 1.35 solar mass white dwarf, with M = 10-9 solar mass, produced peak temperatures in the shell source exceeding 300 million degrees. The sequence produced significant amounts of Na-22 from proton captures onto Ne-20 and significant amounts of Al-26 from proton captures on Mg-24. This sequence ejected 5.2 x 10-6 solar mass moving with speeds from approximately 100 km/s to 2300 km/s. When the mass accretion rate was decreased to 10-10 solar mass, the resulting thermonuclear runaway produced a shock that moved through the outer envelope of the white dwarf and raised the surface luminosity to L greater than 107 solar luminosity and the effective temperature to values exceeding 107 K. The interaction of the material expanding from off of the white dwarf with the accretion disk should produce a burst of gamma-rays.

  7. From quiescence to unrest: 20 years of satellite geodetic measurements at Santorini volcano, Greece

    NASA Astrophysics Data System (ADS)

    Parks, Michelle M.; Moore, James D. P.; Papanikolaou, Xanthos; Biggs, Juliet; Mather, Tamsin A.; Pyle, David M.; Raptakis, Costas; Paradissis, Demitris; Hooper, Andrew; Parsons, Barry; Nomikou, Paraskevi

    2015-02-01

    Periods of unrest at caldera-forming volcanic systems characterized by increased rates of seismicity and deformation are well documented. Some can be linked to eventual eruptive activity, while others are followed by a return to quiescence. Here we use a 20 year record of interferometric synthetic aperture radar (InSAR) and GPS measurements from Santorini volcano to further our understanding of geodetic signals at a caldera-forming volcano during the periods of both quiescence and unrest, with measurements spanning a phase of quiescence and slow subsidence (1993-2010), followed by a phase of unrest (January 2011 to April 2012) with caldera-wide inflation and seismicity. Mean InSAR velocity maps from 1993-2010 indicate an average subsidence rate of 6 mm/yr over the southern half of the intracaldera island Nea Kameni. This subsidence can be accounted for by a combination of thermal contraction of the 1866-1870 lava flows and load-induced relaxation of the substrate. For the period of unrest, we use a joint inversion technique to convert InSAR measurements from three separate satellite tracks and GPS observations from 10 continuous sites into a time series of subsurface volume change. The optimal location of the inflating source is consistent with previous studies, situated north of Nea Kameni at a depth of 4 km. However, the time series reveals two distinct pressure pulses. The first pulse corresponds to a volume change (ΔV) within the shallow magma chamber of (11.56 ± 0.14) × 106 m3, and the second pulse has a ΔV of (9.73 ± 0.10) × 106 m3. The relationship between the timing of these pulses and microseismicity observations suggests that these pulses may be driven by two separate batches of magma supplied to a shallow reservoir. We find no evidence suggesting a change in source location between the two pulses. The decline in the rates of volume change at the end of both pulses and the observed lag of the deformation signal behind cumulative seismicity, suggest

  8. Quiescence in Artemia franciscana embryos: reversible arrest of metabolism and gene expression at low oxygen levels.

    PubMed

    Hand, S C

    1998-04-01

    Depression of the production and consumption of cellular energy appears to be a prerequisite for the survival of prolonged bouts of anoxia. A correlation exists between the degree of metabolic depression under anoxia and the duration of anoxia tolerance. In the case of brine shrimp (Artemia franciscana) embryos, oxygen deprivation induces a reversible quiescent state that can be tolerated for several years with substantial survivorship. A global arrest of cytoplasmic translation accompanies the transition into anoxia, and rates of protein synthesis in mitochondria from these embryos appears to be markedly reduced in response to anoxia. Previous evidence suggests that the acute acidification of intracellular pH (pHi) by over 1.0 unit during the transition into anoxia contributes to the depression of biosynthesis, but message limitation does not appear to play a role in the down-regulation in either cellular compartment. The ontogenetic increase in mRNA levels for a mitochondrial-encoded subunit of cytochrome c oxidase (COX I) and for nuclear-encoded actin is blocked by anoxia and aerobic acidosis (artificial quiescence imposed by intracellular acidification under aerobic conditions). Further, the levels of COX I and actin mRNA do not decline appreciably during 6 h bouts of quiescence, even though protein synthesis is acutely arrested across this same period. Thus, the constancy of mRNA levels during quiescence indicates that reduced protein synthesis is not caused by message limitation but, instead, is probably controlled at the translational level. This apparent stabilization of mRNA under anoxia is mirrored in an extension of protein half-life. The ubiquitin-dependent pathway for protein degradation is depressed under anoxia and aerobic acidosis, as judged by the acute drop in levels of ubiquitin-conjugated proteins. Mitochondrial protein synthesis is responsive to both acidification of pHi and removal of oxygen per se. Matrix pH declines in parallel with pHi, and

  9. FRPR-4 Is a G-Protein Coupled Neuropeptide Receptor That Regulates Behavioral Quiescence and Posture in Caenorhabditis elegans

    PubMed Central

    York, Neil; Lee, Kun He; Schoofs, Liliane; Raizen, David M.

    2015-01-01

    Neuropeptides signal through G-protein coupled receptors (GPCRs) to regulate a broad array of animal behaviors and physiological processes. The Caenorhabditis elegans genome encodes approximately 100 predicted neuropeptide receptor GPCRs, but in vivo roles for only a few have been identified. We describe here a role for the GPCR FRPR-4 in the regulation of behavioral quiescence and locomotive posture. FRPR-4 is activated in cell culture by several neuropeptides with an amidated isoleucine-arginine-phenylalanine (IRF) motif or an amidated valine-arginine-phenylalanine (VRF) motif at their carboxy termini, including those encoded by the gene flp-13. Loss of frpr-4 function results in a minor feeding quiescence defect after heat-induced cellular stress. Overexpression of frpr-4 induces quiescence of locomotion and feeding as well as an exaggerated body bend posture. The exaggerated body bend posture requires the gene flp-13. While frpr-4 is expressed broadly, selective overexpression of frpr-4 in the proprioceptive DVA neurons results in exaggerated body bends that require flp-13 in the ALA neuron. Our results suggest that FLP-13 and other neuropeptides signal through FRPR-4 and other receptors to regulate locomotion posture and behavioral quiescence. PMID:26571132

  10. Atypical Protein Kinase C Isoform, aPKCλ, Is Essential for Maintaining Hair Follicle Stem Cell Quiescence.

    PubMed

    Osada, Shin-Ichi; Minematsu, Naoko; Oda, Fumino; Akimoto, Kazunori; Kawana, Seiji; Ohno, Shigeo

    2015-11-01

    The atypical protein kinase C (aPKC)-partition-defective (PAR) complex regulates the formation of tight junctions and apico-basal epithelial polarity. To examine the role of this complex in the epidermis, we generated mutant mice harboring epidermal-specific deletion of aPKCλ (conditional knock-out (cKO)), a major component of the aPKC-PAR complex. The mutant mice exhibited abnormal hair follicle (HF) cycling, progressive losses of pelage hairs and vibrissae, and altered differentiation into the epidermis and sebaceous gland. We found that in the aPKCλ cKO mice HF stem cell (HFSC) quiescence was lost, as revealed by the decreased expression level of quiescence-inducing factors (Fgf18 and Bmp6) produced in Keratin 6-positive bulge stem cells. The loss of quiescence dysregulated the HFSC marker expression and led to the increase in Lrig1-positive cells, inducing hyperplasia of the interfollicular epidermis and sebaceous glands, and drove an increase in Lef1-positive matrix cells, causing a prolonged anagen-like phase. Persistent bulge stem cell activation led to a gradual depletion of CD34- and α6 integrin-positive HFSC reservoirs. These results suggest that aPKCλ regulates signaling pathways implicated in HFSC quiescence.

  11. Comparison of pregabalin with pramipexole for restless legs syndrome.

    PubMed

    Allen, Richard P; Chen, Crystal; Garcia-Borreguero, Diego; Polo, Olli; DuBrava, Sarah; Miceli, Jeffrey; Knapp, Lloyd; Winkelman, John W

    2014-02-13

    Dopaminergic medications relieve symptoms of the restless legs syndrome (RLS) but have the potential to cause iatrogenic worsening (augmentation) of RLS with long-term treatment. Pregabalin may be an effective alternative. In this 52-week, randomized, double-blind trial, we assessed efficacy and augmentation in patients with RLS who were treated with pregabalin as compared with placebo and pramipexole. Patients were randomly assigned to receive 52 weeks of treatment with pregabalin at a dose of 300 mg per day or pramipexole at a dose of 0.25 mg or 0.5 mg per day or 12 weeks of placebo followed by 40 weeks of randomly assigned active treatment. The primary analyses involved a comparison of pregabalin and placebo over a period of 12 weeks with use of the International RLS (IRLS) Study Group Rating Scale (on which the score ranges from 0 to 40, with a higher score indicating more severe symptoms), the Clinical Global Impression of Improvement scale (which was used to assess the proportion of patients with symptoms that were "very much improved" or "much improved"), and a comparison of rates of augmentation with pregabalin and pramipexole over a period of 40 or 52 weeks of treatment. A total of 719 participants received daily treatment, 182 with 300 mg of pregabalin, 178 with 0.25 mg of pramipexole, 180 with 0.5 mg of pramipexole, and 179 with placebo. Over a period of 12 weeks, the improvement (reduction) in mean scores on the IRLS scale was greater, by 4.5 points, among participants receiving pregabalin than among those receiving placebo (P<0.001), and the proportion of patients with symptoms that were very much improved or much improved was also greater with pregabalin than with placebo (71.4% vs. 46.8%, P<0.001). The rate of augmentation over a period of 40 or 52 weeks was significantly lower with pregabalin than with pramipexole at a dose of 0.5 mg (2.1% vs. 7.7%, P=0.001) but not at a dose of 0.25 mg (2.1% vs. 5.3%, P=0.08). There were six cases of suicidal

  12. Restless legs syndrome: relationship between prevalence and latitude.

    PubMed

    Koo, Brian B

    2012-12-01

    Restless legs syndrome (RLS) has a broad worldwide prevalence between 0.01% and 18.3%. While differences in RLS definitions and data ascertainment methods account for some variability, other factors likely contribute. The circadian nature of RLS and the fact that RLS symptoms track with endogenous melatonin levels suggest that light or ultraviolet radiation (UVR) may be related to RLS expression. As the amount of UVR decreases with latitude, we considered the potential effect of geography on RLS prevalence with the thought being that RLS prevalence rises with increasing latitude. RLS epidemiologic studies were sought via Pubmed search in the period between January 1, 1992 and November 15, 2010. Prevalence was mapped for each country or specific region studied and examined by continent. Pearson's correlational testing was carried out for RLS prevalence and latitude of the region studied. Global RLS prevalence ranges from 0.01% in Africa, 0.7% to 12.5% in Asia, 2.0% to 18.9% in the Americas, and 3.2% to 18.3% in Europe. Mapping RLS prevalence by country or region in both the Americas and in Europe suggests increasing RLS frequency with greater northern latitude. RLS prevalence is positively correlated with northern latitude in both North America and Europe with correlation coefficients of r = 0.77 (0.15, 0.96; p = 0.02) and r = 0.74 (0.44, 0.89; p = 0.0002), respectively. In Europe, lower latitudinal countries like Greece and Turkey had RLS prevalence (per 1,000 persons) of 38 and 34, respectively, middle latitudinal countries like France and England of 108 and 86, respectively, and high latitudinal countries like Norway and Iceland of 143 and 183, respectively. RLS epidemiology indicates an increase in RLS frequency in northern latitudinal countries as a function of distance from the equator, an effect most evident in Europe. This suggests that factors that track with latitude like UVR may be involved in the expression of RLS.

  13. Transdermal rotigotine for the perioperative management of restless legs syndrome

    PubMed Central

    2012-01-01

    Background Immobilisation, blood loss, sleep deficiency, and (concomitant) medications during perioperative periods might lead to acute exacerbation of symptoms in patients with the restless legs syndrome (RLS). Continuous transdermal delivery of the dopamine agonist rotigotine provides stable plasma levels over 24 h and may provide RLS patients with a feasible treatment option for perioperative situations. To assess the feasibility of use of rotigotine transdermal patch for the perioperative management of moderate to severe RLS, long-term data of an open-label extension of a rotigotine dose-finding study were retrospectively reviewed. Methods The data of all 295 patients who had entered the 5-year study were screened independently by two reviewers for the occurrence of surgical interventions during the study period. The following data were included in this post-hoc analysis: patient age, sex, surgical intervention and outcome, duration of hospital stay, rotigotine maintenance dose at the time of surgery, rotigotine dose adjustment, and continuation/discontinuation of rotigotine treatment. All parameters were analysed descriptively. No pre-specified efficacy assessments (e.g. IRLS scores) were available for the perioperative period. Results During the study period, 61 surgical interventions were reported for 52 patients (median age, 63 years; 67% female); the majority of patients (85%) had one surgical intervention. The mean rotigotine maintenance dose at time of surgery was 3.1 ± 1.1 mg/24 h. For most interventions (95%), rotigotine dosing regimens were maintained during the perioperative period. Administration was temporarily suspended in one patient and permanently discontinued in another two. The majority (96%) of the patients undergoing surgery remained in the study following the perioperative period and 30 of these patients (61%) completed the 5-year study. Conclusions Although the data were obtained from a study which was not designed to assess

  14. Restless leg syndrome is a treatable cause of sleep disturbance and fatigue in primary biliary cirrhosis.

    PubMed

    Anderson, Kirstie; Jones, David E J; Wilton, Katharine; Newton, Julia L

    2013-02-01

    Primary biliary cirrhosis (PBC) patients frequently describe sleep problems. The cause remains unclear and treatment is challenging. Restless leg syndrome (RLS) is a common sleep disorder. In this study, we systematically screened PBC patients for the presence of RLS. Participants were recruited from our specialist PBC clinical service. Subjects completed the International Restless Leg Syndrome Study Group rating scale (IRLSS) a validated measure of the presence of RLS and its severity. Those fulfilling diagnostic criteria for RLS underwent foot actigraphy (CamNtech Actiwatch) to objectively assess periodic limb movement index (PLMI) (normal <5/h). Restless leg syndrome was assessed in 42 consecutive early stage PBC patients. Twelve (29%) fulfilled the IRLSS criteria for RLS. Scores were significantly higher in PBC compared to controls (P = 0.005). Twenty-four patients were further assessed with foot actigraphy for 3 nights (12 with subjective RLS symptoms and 12 with no RLS symptoms). Thirteen of twenty-four subjects had PLMI >5/h and four had moderate or severe PLMI >15/h. All moderate or severe PLMI subjects had subjective symptoms of moderate or severe RLS. No patients had PLMI >10 in the absence of RLS symptoms. Eleven PBC patients with symptomatic RLS went on to have treatment. Sixty-three per cent had clear benefit in restless leg symptoms and associated symptoms of fatigue. Restless leg syndrome symptoms are common and underdiagnosed in PBC patients. RLS represents a potential therapy for PBC patients with daytime sleepiness, fatigue and unpleasant lower limb symptoms and this is worthy of further studies in larger cohorts. © 2012 John Wiley & Sons A/S.

  15. Sex and the risk of restless legs syndrome in the general population.

    PubMed

    Berger, Klaus; Luedemann, Jan; Trenkwalder, Claudia; John, Ulrich; Kessler, Christof

    2004-01-26

    Restless legs syndrome (RLS) is characterized by the desire to move the limbs associated with paresthesias of the legs, a motor restlessness, an intensification of symptoms at rest with relief by activity, and a worsening of symptoms in the evening or at night. Population-based studies are rare, and risk factors in the general population are not known. Cross-sectional survey with face-to-face interviews and physical examination among 4310 participants in the Study of Health in Pomerania in northeastern Germany. Participants were aged 20 to 79 years and were randomly selected from population registers. Restless legs syndrome was assessed with standardized, validated questions addressing the 4 minimal criteria for RLS as defined by the International Restless Legs Syndrome Study Group. The overall prevalence of RLS was 10.6%, increasing with age, and women were twice as often affected as men. While nulliparous women had prevalences similar to those among men up to age 64 years, the risk of RLS increased gradually for women with 1 child (odds ratio, 1.98; 95% confidence interval, 1.25-3.13), 2 children (odds ratio, 3.04; 95% confidence interval, 2.11-4.40), and 3 or more children (odds ratio, 3.57; 95% confidence interval, 2.30-5.55). Subjects with RLS had significantly lower quality-of-life scores than those without the syndrome. Restless legs syndrome is a common disease in the general population, affecting women more often than men. It is associated with reduced quality of life in cross-sectional analysis. Parity is a major factor in explaining the sex difference and may guide further clarification of the etiology of the disease.

  16. Effect of sensory stimuli on restless legs syndrome: a randomized crossover study.

    PubMed

    Rozeman, Anouk D; Ottolini, Truus; Grootendorst, Diana C; Vogels, Oscar J M; Rijsman, Roselyne M

    2014-08-15

    A variety of sensory stimuli relieve restless legs syndrome symptoms. Because systematic evaluations of sensory stimulation in restless legs syndrome are largely lacking, we performed a randomized crossover study to evaluate the effect of external sensory stimulation on restless legs syndrome symptoms. Eighteen patients underwent 3 consecutive suggestive immobilization tests with the order of the following 3 conditions randomly assigned: no electrical stimulation (condition 1), tactile and proprioceptive sensory stimulation (condition 2), and tactile sensory stimulation only (condition 3). Restless legs syndrome symptoms were quantified by visual analog scales, and periodic leg movements during wake were measured. Baseline visual analogue scale score was 4.5 (range 0-60) in condition 1, 10.5 (range 0-96) in condition 2, and 8.5 in condition 3 (p = 0.21). There was a tendency towards a higher maximum visual analogue scale score and visual analogue scale score at the end of the suggested immobilization test in the conditions with tactile sensory stimulation, though not significant (p = 0.74 and p = 0.29, respectively). Fifteen patients suffered from periodic leg movements during wake. Median indices were 18 (range 0-145) in condition 1, 26 (range 0-190) in condition 2, and 49 (range 0-228) in condition 3 (p = 0.76). We found a tendency towards less leg discomfort in the conditions in which an external sensory input was applied. This potential benefit of sensory stimuli on restless legs syndrome severity merits further investigation as this could open new ways towards a better pathophysiological understanding and non-pharmacological treatments.

  17. Actigraphic assessment of periodic leg movements in patients with restless legs syndrome.

    PubMed

    Cippà, Maria A T; Baumann, Christian R; Siccoli, Massimiliano M; Bassetti, Claudio L; Poryazova, Rositsa; Werth, Esther

    2013-10-01

    The diagnosis of restless legs syndrome (RLS) relies upon diagnostic criteria which are based on history only, and dopaminergic treatment is not normally the first choice of treatment for all patients. It would be worthwhile to identify patients non-responsive to dopaminergic treatment beforehand, because they may suffer from a restless legs-like syndrome and may require alternative treatment. We included retrospectively 24 adult patients fulfilling the four essential criteria for restless legs and 12 age-matched healthy controls. They were investigated by ambulatory actigraphy from both legs over three nights, and patients started treatment with dopamine agonists after this diagnostic work-up. We examined 12 responders to dopaminergic treatment and 12 non-responders and studied the association between response to dopaminergic treatment and the periodic limb movement index (PLMI) as assessed with actigraphy. Demographic characteristics, excessive daytime sleepiness and fatigue at baseline were similar in all three groups. Baseline RLS severity was similar between responders and non-responders [International Restless Legs Severity Scale (IRLS): 25 ± 9 and 24 ± 8]. Group comparisons of PLMI before treatment initiation showed significant differences between the three groups. Post-hoc pairwise comparisons revealed that healthy controls had significantly lower PLMI (4.9 ± 4.5) than responders (29.3 ± 22.7) and non-responders (13.3 ± 11.2). Similarly, the PLMI in responders was lower than in non-responders. PLMI day-to-day variability did not differ between responders and non-responders and there was no correlation between treatment effect, as assessed by the decrease of the IRLS and baseline PLMI. Our retrospective study indicates that actigraphy to assess periodic limb movements may contribute to a better diagnosis of dopamine-responsive restless legs syndrome.

  18. Uropathogenic Escherichia coli Metabolite-Dependent Quiescence and Persistence May Explain Antibiotic Tolerance during Urinary Tract Infection

    PubMed Central

    Leatham-Jensen, Mary P.; Mokszycki, Matthew E.; Rowley, David C.; Deering, Robert; Camberg, Jodi L.; Sokurenko, Evgeni V.; Tchesnokova, Veronika L.; Frimodt-Møller, Jakob; Leth Nielsen, Karen; Sun, Gongqin

    2016-01-01

    ABSTRACT In the present study, it is shown that although Escherichia coli CFT073, a human uropathogenic (UPEC) strain, grows in liquid glucose M9 minimal medium, it fails to grow on glucose M9 minimal medium agar plates seeded with ≤106 CFU. The cells on glucose plates appear to be in a “quiescent” state that can be prevented by various combinations of lysine, methionine, and tyrosine. Moreover, the quiescent state is characteristic of ~80% of E. coli phylogenetic group B2 multilocus sequence type 73 strains, as well as 22.5% of randomly selected UPEC strains isolated from community-acquired urinary tract infections in Denmark. In addition, E. coli CFT073 quiescence is not limited to glucose but occurs on agar plates containing a number of other sugars and acetate as sole carbon sources. It is also shown that a number of E. coli CFT073 mini-Tn5 metabolic mutants (gnd, gdhA, pykF, sdhA, and zwf) are nonquiescent on glucose M9 minimal agar plates and that quiescence requires a complete oxidative tricarboxylic acid (TCA) cycle. In addition, evidence is presented that, although E. coli CFT073 quiescence and persistence in the presence of ampicillin are alike in that both require a complete oxidative TCA cycle and each can be prevented by amino acids, E. coli CFT073 quiescence occurs in the presence or absence of a functional rpoS gene, whereas maximal persistence requires a nonfunctional rpoS. Our results suggest that interventions targeting specific central metabolic pathways may mitigate UPEC infections by interfering with quiescence and persistence. IMPORTANCE Recurrent urinary tract infections (UTIs) affect 10 to 40% of women. In up to 77% of those cases, the recurrent infections are caused by the same uropathogenic E. coli (UPEC) strain that caused the initial infection. Upon infection of urothelial transitional cells in the bladder, UPEC appear to enter a nongrowing quiescent intracellular state that is thought to serve as a reservoir responsible

  19. An Slfn2 mutation causes lymphoid and myeloid immunodeficiency due to loss of immune cell quiescence.

    PubMed

    Berger, Michael; Krebs, Philippe; Crozat, Karine; Li, Xiaohong; Croker, Ben A; Siggs, Owen M; Popkin, Daniel; Du, Xin; Lawson, Brian R; Theofilopoulos, Argyrios N; Xia, Yu; Khovananth, Kevin; Moresco, Eva Marie; Satoh, Takashi; Takeuchi, Osamu; Akira, Shizuo; Beutler, Bruce

    2010-04-01

    Here we describe a previously unknown form of inherited immunodeficiency revealed by an N-ethyl-N-nitrosourea-induced mutation called elektra. Mice homozygous for this mutation showed enhanced susceptibility to bacterial and viral infection and diminished numbers of T cells and inflammatory monocytes that failed to proliferate after infection and died via the intrinsic apoptotic pathway in response to diverse proliferative stimuli. They also had a greater proportion of T cells poised to replicate DNA, and their T cells expressed a subset of activation markers, suggestive of a semi-activated state. We positionally ascribe the elektra phenotype to a mutation in the gene encoding Schlafen-2 (Slfn2). Our findings identify a physiological role for Slfn2 in the defense against pathogens through the regulation of quiescence in T cells and monocytes.

  20. A Slfn2 mutation causes lymphoid and myeloid immunodeficiency due to loss of immune cell quiescence

    PubMed Central

    Berger, Michael; Krebs, Philippe; Crozat, Karine; Li, Xiaohong; Croker, Ben A.; Siggs, Owen M.; Popkin, Daniel; Du, Xin; Lawson, Brian R.; Theofilopoulos, Argyrios N.; Xia, Yu; Khovananth, Kevin; Moresco, Eva Marie Y.; Satoh, Takashi; Takeuchi, Osamu; Akira, Shizuo; Beutler, Bruce

    2010-01-01

    We describe a new form of inherited immunodeficiency revealed by an N-ethyl-N-nitrosourea (ENU)-induced mutation called elektra. Homozygotes showed enhanced susceptibility to bacterial and viral infections, and diminished numbers of T cells and inflammatory monocytes that failed to proliferate upon infection and died via the intrinsic apoptotic pathway in response to diverse proliferative stimuli. Elektra mice exhibited an increased proportion of T cells poised to replicate DNA and their T cells expressed a subset of activation markers, suggestive of a semi-activated state. The elektra phenotype was positionally ascribed to a mutation in the gene encoding Schlafen-2 (Slfn2). Our findings reveal a physiological role for Slfn2 in the defense against pathogens through regulation of quiescence in T cells and monocytes. PMID:20190759