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Sample records for restless quiescence thermonuclear

  1. Restless Legs

    MedlinePlus

    Restless legs syndrome (RLS) causes a powerful urge to move your legs. Your legs become uncomfortable when you are lying down or ... crawling, tingling, or burning sensation. Moving makes your legs feel better, but not for long. RLS can ...

  2. Modelling mammalian cellular quiescence

    PubMed Central

    Yao, Guang

    2014-01-01

    Cellular quiescence is a reversible non-proliferating state. The reactivation of ‘sleep-like’ quiescent cells (e.g. fibroblasts, lymphocytes and stem cells) into proliferation is crucial for tissue repair and regeneration and a key to the growth, development and health of higher multicellular organisms, such as mammals. Quiescence has been a primarily phenotypic description (i.e. non-permanent cell cycle arrest) and poorly studied. However, contrary to the earlier thinking that quiescence is simply a passive and dormant state lacking proliferating activities, recent studies have revealed that cellular quiescence is actively maintained in the cell and that it corresponds to a collection of heterogeneous states. Recent modelling and experimental work have suggested that an Rb-E2F bistable switch plays a pivotal role in controlling the quiescence–proliferation balance and the heterogeneous quiescent states. Other quiescence regulatory activities may crosstalk with and impinge upon the Rb-E2F bistable switch, forming a gene network that controls the cells’ quiescent states and their dynamic transitions to proliferation in response to noisy environmental signals. Elucidating the dynamic control mechanisms underlying quiescence may lead to novel therapeutic strategies that re-establish normal quiescent states, in a variety of hyper- and hypo-proliferative diseases, including cancer and ageing. PMID:24904737

  3. Restless legs syndrome

    MedlinePlus

    ... they sleep. This condition is called periodic limb movement disorder. All of these symptoms make it hard to ... treatment of restless legs syndrome and periodic limb movement disorder in adults-an update for 2012: practice parameters ...

  4. Restless Legs Syndrome

    MedlinePlus

    ... Funding Information Research Programs Training & Career Awards Enhancing Diversity Find People About NINDS NINDS Restless Legs Syndrome ... News From NINDS | Find People | Training | Research | Enhancing Diversity Careers@NINDS | FOIA | Accessibility Policy | Contact Us | Privacy ...

  5. 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.

  6. Assessing the likelihood and magnitude of volcanic explosions based on seismic quiescence

    NASA Astrophysics Data System (ADS)

    Roman, Diana C.; Rodgers, Mel; Geirsson, Halldor; LaFemina, Peter C.; Tenorio, Virginia

    2016-09-01

    Volcanic eruptions are generally forecast based on strong increases in monitoring parameters such as seismicity or gas emissions above a relatively low background level (e.g., Voight, 1988; Sparks, 2003). Because of this, forecasting individual explosions during an ongoing eruption, or at persistently restless volcanoes, is difficult as seismicity, gas emissions, and other indicators of unrest are already in a heightened state. Therefore, identification of short-term precursors to individual explosions at volcanoes already in heightened states of unrest, and an understanding of explosion trigger mechanisms, is important for the reduction of volcanic risk worldwide. Seismic and visual observations at Telica Volcano, Nicaragua, demonstrate that a) episodes of seismic quiescence reliably preceded explosions during an eruption in May 2011 and b) the duration of precursory quiescence and the energy released in the ensuing explosion were strongly correlated. Precursory seismic quiescence is interpreted as the result of sealing of shallow gas pathways, leading to pressure accumulation and eventual catastrophic failure of the system, culminating in an explosion. Longer periods of sealing and pressurization lead to greater energy release in the ensuing explosion. Near-real-time observations of seismic quiescence at restless or erupting volcanoes can thus be useful for both timely eruption warnings and for forecasting the energy of impending explosions.

  7. 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.

  8. 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. PMID:27512466

  9. EX Lupi in quiescence

    NASA Astrophysics Data System (ADS)

    Sipos, N.; Ábrahám, P.; Acosta-Pulido, J.; Juhász, A.; Kóspál, Á.; Kun, M.; Moór, A.; Setiawan, J.

    2009-11-01

    Aims: EX Lupi is the prototype of EXors, a subclass of low-mass pre-main sequence stars whose episodic eruptions are attributed to temporarily increased accretion. In quiescence the optical and near-infrared properties of EX Lup cannot be distinguished from those of normal T Tau stars. Here we investigate whether it is the circumstellar disk structure that makes EX Lup an atypical Class II object. During outburst the disk might undergo structural changes. Our characterization of the quiescent disk is intended to serve as a reference for studying the physical changes related to one of EX Lupi's strongest known eruptions in 2008 Jan-Sep. Methods: We searched the literature for photometric and spectroscopic observations including ground-based, IRAS, ISO, and Spitzer data. After constructing the optical-infrared spectral energy distribution (SED), we compared it with the typical SEDs of other young stellar objects and modeled it using the Monte Carlo radiative transfer code RADMC. We determined the mineralogical composition of the 10 μm silicate emission feature and also gave a description of the optical and near-infrared spectra. Results: The SED is similar to that of a typical T Tauri star in most aspects, though EX Lup emits higher flux above 7 μm. The quiescent phase data suggest low-level variability in the optical-mid-infrared domain. By integrating the optical and infrared fluxes, we derived a bolometric luminosity of 0.7 L⊙. The 10 μm silicate profile could be fitted by a mixture consisting of amorphous silicates, but no crystalline silicates were found. A modestly flaring disk model with a total mass of 0.025 M⊙ and an outer radius of 150 AU was able to reproduce the observed SED. The derived inner radius of 0.2 AU is larger than the sublimation radius, and this inner gap sets EX Lup apart from typical T Tauri stars. Full Table 3 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb

  10. Restless Eating, Restless Legs, and Sleep Related Eating Disorder.

    PubMed

    Howell, Michael J

    2014-03-01

    Restless legs syndrome (RLS) often presents with a primary complaint of sleep initiation difficulty with only ambiguous allusions to motor symptoms. This may result in the condition being misdiagnosed as a psychophysiological insomnia. Further, nocturnal eating is common in RLS and like the classic motor symptoms, patients will describe an inability to initiate sleep until their urge (to eat) is addressed. Restless nocturnal eating arises, intensifies, and subsides in parallel to motor symptoms. Once misdiagnosed as psychophysiological insomnia, RLS patients are frequently treated with benzodiazepine receptor agonists. The CNS actions of these sedating agents, suppression of memory and executive function, unleash predisposed amnestic behaviors. In the case of RLS this would be expected to include the inappropriate ambulatory and eating behaviors of sleep related eating disorder (SRED). The evidence and implications of a link between the restless eating of RLS and SRED is presented here.

  11. 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.

  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. 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

  14. Restlessness related to SSRI withdrawal.

    PubMed

    Hirose, S

    2001-02-01

    There are reports that abrupt withdrawal of various selective serotonin re-uptake inhibitors, such as fluvoxamine, can elicit in patients various withdrawal symptoms. Fluvoxamine has been widely used in Japan for approximately 1 year. However, there have been no case reports of withdrawal symptoms following abrupt fluvoxamine discontinuation in Japan. The author reports a case where the abrupt discontinuation of fluvoxamine produced restlessness in a depressed patient. The restlessness disappeared soon after the reinstatement of treatment with fluvoxamine. This case report suggests that clinicians should carefully scrutinize a patient's compliance to fluvoxamine as the withdrawal symptoms observed following abrupt discontinuation might be regarded as a relapse of depression or side-effects of the medicine. PMID:11235863

  15. Treatment of restless legs syndrome.

    PubMed

    Ferini-Strambi, Luigi; Manconi, Mauro

    2009-12-01

    Restless legs syndrome (RLS) is a common condition characterized by an urge to move the legs, accompanied by uncomfortable or unpleasant sensations. Symptoms predominantly occur at rest in the evening or at night, and they are alleviated by moving the affected extremity or by walking. Recent European epidemiological studies reported an overall prevalence of RLS up to 10%, with a female preponderance. The prevalence rates reported in south-eastern Europe are lower, as are those in Asiatic populations. Although the aetiopathogenesis of RLS is still unknown, the rapid and dramatic improvement of RLS with dopaminergic compounds suggests a dopaminergic system dysfunction as the basic mechanism. Extensive data are available for l-dopa and dopamine receptor agonists, especially for pramipexole and ropinirole. Pharmacological treatment should be limited to those patients who suffer from clinically relevant RLS with impaired sleep quality or quality of life. Treatment on demand is a clinical need in RLS cases that present intermittent symptoms. PMID:20123560

  16. 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. PMID:27079737

  17. Restless Legs Syndrome -- Causes and Symptoms

    MedlinePlus

    ... health issues or medication. This may include: Low iron levels This can cause problems with brain cell ... you have restless legs syndrome caused by low iron, talk with your physician and do not attempt ...

  18. Iron for restless legs syndrome

    PubMed Central

    Trotti, Lynn M; Bhadriraju, Srinivas; Becker, Lorne A

    2014-01-01

    Background Restless legs syndrome (RLS) is a common neurologic syndrome and is associated with iron deficiency in many patients. It is unclear whether iron therapy is effective treatment for RLS. Objectives The objective of this review was to assess the effects of iron supplementation (oral or intravenous) for patients with RLS. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Jan 1995 to April 2011); EMBASE (Jan 1995 to April 2011); PsycINFO (Jan 1995 to April 2011); and CINAHL (Jan 1995 to April 2011). Corresponding authors of included trials and additional members of the International Restless Legs Syndrome Study Group were contacted to locate additional published or unpublished trials. Selection criteria Controlled trials comparing any formulation of iron with placebo, other medications, or no treatment in adults diagnosed with RLS according to expert clinical interview or explicit diagnostic criteria. Data collection and analysis Two review authors extracted data and at least two authors assessed trial quality. We contacted trial authors for missing data. Main results Six studies (192 total subjects) were identified and included in this analysis. The quality of trials was variable. Our primary outcome was restlessness or uncomfortable leg sensations, which was quantified using the IRLS severity scale in four trials and another RLS symptom scale in a fifth trial. Combining data from the four trials using the IRLS severity scale, there was no clear benefit from iron therapy (mean difference in IRLS severity scores of -3.79, 95% CI: -7.68 to 0.10, p = 0.06). However, the fifth trial did find iron therapy to be beneficial (median decrease of 3 points in the iron group and no change in the placebo group on a 10 point scale of RLS symptoms, p = 0.01). Quality of life was improved in the iron group relative to placebo in some studies but not others. Changes in periodic limb movements were not different between groups

  19. Thermonuclear ignition criterion in ICF

    NASA Astrophysics Data System (ADS)

    Cheng, Baolian

    2010-11-01

    The Lawson criterion, which determines the onset of thermonuclear ignition in inertial confinement fusion (ICF), is re-derived in terms of physical measurable quantities: the hot spot ion temperature T and the areal density (ρR) of the deuterium-tritium (DT) gas. From this criterion, an ignition curve is generated in the ρR -T plane. In addition, a minimal required implosion energy for laser-drive and a minimal DT gas mass for a sustainable ignition with respect to the condition are derived.

  20. 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.

  1. 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

    2016-01-01

    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. PMID:27629973

  2. 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.

  3. 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

  4. On extended thermonuclear functions through pathway model

    NASA Astrophysics Data System (ADS)

    Kumar, Dilip

    when α → 1. The beauty of the result is that these different families of three different functional forms are covered through the pathway parameter α. In a physical set up if f (x) in (3) is the stable or limiting form, the Maxwell-Boltzmann approach to thermonuclear functions, then f (x) in (1) and (2) will contain a large variety of unstable or chaotic situations which will all tend to (3) in the limit. Thus we get a clear idea of all the stable and unstable situations around the Maxwell-Boltzmann approach. Thus the current theory is given a mathematical extension and physical interpretations can be found to situations in (1) and (2). Incidently Tsallis statistics is a special case of (1) for γ = 0, a = 1, δ = 1, η = 1. The Beck-Cohen superstatistics, discussed in current statistical mechanics literature is a special case of (2) for a = 1, η = 1, α > 1. The main purpose of the present paper is to investigate in some more detail, mathematically, the extended thermonuclear functions for Maxwell-Boltzmann statistics and in the cut-off case. The extended thermonuclear functions will be evaluated in closed form for all convenient values of the parameter by means of residue calculus. A comparison of the standard thermonuclear functions with the extended thermonuclear functions is also done. The results and derivations in this paper are new and these will be of interest to physicists, mathematicians, probabilists, and statisticians.

  5. Restlessness in right upper limb as sole presentation of restless legs syndrome

    PubMed Central

    Gupta, Ravi; Lahan, Vivekananda; Goel, Deepak

    2013-01-01

    Restless legs syndrome (RLS) rarely affects the upper limb during the initial course of disease. We present a patient who complained of symptoms suggesting RLS in the right upper limb as the sole manifestation of illness. Bilateral cervical ribs and depression were co-incidental findings. Patient responded well to dopaminergic therapy. PMID:23546363

  6. The Construct Validity of the Internal Restlessness Scale

    ERIC Educational Resources Information Center

    Weyandt, Lisa; Hays, Brian; Schepman, Stephen

    2005-01-01

    The present study investigated the construct validity of the Internal Restlessness Scale (IRS), a self-report instrument developed to measure feelings of restlessness in young adults with ADHD, and the relationship between the IRS and a neuropsychological, behavioral task (i.e., continuous performance test). Pearson product-moment correlations…

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. Thermonuclear milestones: (1) The American effort

    SciTech Connect

    Goncharov, G.A.

    1996-11-01

    It took a decade for scientists in America to develop the first ideas for a {open_quote}Super{close_quote} bomb into a device that ignited {open_quote}the first small thermonuclear flame ever to burn on Earth.{close_quote} {copyright} {ital 1996 American Institute of Physics.}

  13. 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

  14. The yeast genome undergoes significant topological reorganization in quiescence.

    PubMed

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

    2015-09-30

    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

  15. Restlessness in suboccipital muscles as a manifestation of akathisia.

    PubMed

    Hirose, S

    2001-02-01

    Antipsychotic-induced akathisia is primarily manifested as restlessness, particularly expressed in the legs. Consequently, rating scales and the research criteria of DSM-IV regard restlessness in the legs as the major sign of akathisia, although it has been suggested that such restlessness may occur in other areas of the body. A case of antipsychotic-induced akathisia is reported where the region of inner restlessness (the subjective component) was identified in posterior cervical muscles. The patient was initially suspected to be experiencing somatic delusions and the dose of antipsychotic medication was increased. This did not improve the symptoms, and upon careful questioning about his head discomfort, the patient acknowledged that he felt an inner restlessness in the suboccipital muscles. The restlessness ceased with intramuscular biperiden and subsequent discontinuation of antipsychotic medication. This case suggests that subjective restlessness may occur in muscle groups that are not usually associated with akathisia. Thus, this report may assist clinicians in the diagnosis of akathisia that could be overlooked or misdiagnosed as somatic delusions or the worsening of the patient's psychosis. PMID:11235864

  16. 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. PMID:23630372

  17. 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.

  18. 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. PMID:21422649

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

    MedlinePlus

    ... Benefits Side Effects Variations Tips Healthy Sleep Habits Sleep Disorders by Category Insomnias Insomnia Child Insomnia Short Sleeper ... and Facts Restless legs syndrome is a neurological sleep disorder that make you have an overwhelming urge to ...

  20. Global arrest of translation during invertebrate quiescence.

    PubMed

    Hofmann, G E; Hand, S C

    1994-08-30

    Comparing the translational capacities of cell-free systems from aerobically developing embryos of the brine shrimp Artemia franciscana vs. quiescent embryos has revealed a global arrest of protein synthesis. Incorporation rates of [3H]leucine by lysates from 4-h anoxic embryos were 8% of those from aerobic (control) embryos, when assayed at the respective pH values measured for each treatment in vivo. Exposure of embryos to 4 h of aerobic acidosis (elevated CO2 in the presence of oxygen) suppressed protein synthesis to 3% of control values. These latter two experimental treatments promote developmental arrest of Artemia embryos and, concomitantly, cause acute declines in intracellular pH. When lysates from each treatment were assayed over a range of physiologically relevant pH values (pH 6.4-8.0), amino acid incorporation rates in lysates from quiescent embryos were consistently lower than values for the aerobic controls. Acute reversal of pH to alkaline values during the 6-min assays was not sufficient to return the incorporation rates of quiescent lysates to control values. Thus, a stable alteration in translational capacity of quiescent lysates is indicated. Addition of exogenous mRNA did not rescue the suppressed protein synthesis in quiescent lysates, which suggests that the acute blockage of amino acid incorporation is apparently not due to limitation in message. Thus, the results support a role for intracellular pH as an initial signaling event in translational control during quiescence yet, at the same time, indicate that a direct proton effect on the translational machinery is not the sole proximal agent for biosynthetic arrest in this primitive crustacean. PMID:8078909

  1. 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.

  2. Compton scattering in ignited thermonuclear plasmas.

    PubMed

    Hartemann, F V; Siders, C W; Barty, C P J

    2008-03-28

    Inertially confined, ignited thermonuclear D-T plasmas will produce intense blackbody radiation at temperatures T greater, similar20 keV; it is shown that the injection of GeV electrons into the burning core can efficiently generate high-energy Compton scattering photons. Moreover, the spectrum scattered in a small solid angle can be remarkably monochromatic, due to kinematic pileup; a peak brightness in excess of 10;{30} photons/(mm(2) mrad(2) s 0.1% bandwidth) is predicted. These results are discussed within the context of the Schwinger field and the Sunyaev-Zel'dovich effect.

  3. 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. PMID:26329429

  4. 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

  5. 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.

  6. 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

  7. 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…

  8. Asenapine-Induced Restless Legs Syndrome: Differentiation from Akathisia

    PubMed Central

    McCall, W. Vaughn; Riley, Mary Anne; Hodges, Chelsea; McCloud, Laryssa; Phillips, Marjorie; Rosenquist, Peter B.

    2014-01-01

    Akathisia and restless legs syndrome (RLS) share some common clinical features and a common relationship with dopamine dysfunction. However, the underlying causes and appropriate treatments for akathisia and RLS are different. Herein we describe a case of RLS that was precipitated by a single dose of asenapine, which is an atypical antipsychotic, and dissect the features that support the contention that this was indeed a case of RLS and not akathisia. Citation: McCall WV, Riley MA, Hodges C, McCloud L, Phillips M, Rosenquist PB. Asenapine-induced restless legs syndrome: differentiation from akathisia. J Clin Sleep Med 2014;10(12):1341-1342. PMID:25325577

  9. 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

  10. 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.).

  11. 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.).

  12. 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…

  13. Global Promoter Targeting of a Conserved Lysine Deacetylase for Transcriptional Shutoff during Quiescence Entry.

    PubMed

    McKnight, Jeffrey N; Boerma, Joseph W; Breeden, Linda L; Tsukiyama, Toshio

    2015-09-01

    Quiescence is a conserved cell-cycle state characterized by cell-cycle arrest, increased stress resistance, enhanced longevity, and decreased transcriptional, translational, and metabolic output. Although quiescence plays essential roles in cell survival and normal differentiation, the molecular mechanisms leading to this state are not well understood. Here, we determined changes in the transcriptome and chromatin structure of S. cerevisiae upon quiescence entry. Our analyses revealed transcriptional shutoff that is far more robust than previously believed and an unprecedented global chromatin transition, which are tightly correlated. These changes require Rpd3 lysine deacetylase targeting to at least half of gene promoters via quiescence-specific transcription factors including Xbp1 and Stb3. Deletion of RPD3 prevents cells from establishing transcriptional quiescence, leading to defects in quiescence entry and shortening of chronological lifespan. Our results define a molecular mechanism for global reprogramming of transcriptome and chromatin structure for quiescence driven by a highly conserved chromatin regulator.

  14. 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.

  15. Energy Balance of Controlled Thermonuclear Fusion

    NASA Astrophysics Data System (ADS)

    Hashmi, M.; Staudenmaier, G.

    It is shown that a discrepancy and incompatibility persist between basic physics and fusion-literature regarding the radiation losses from a thermonuclear plasma. Whereas the fusion-literature neglects the excitation or line radiation completely, according to basic physics it depends upon the prevailing conditions and cannot be neglected in general. Moreover, for a magnetized plasma, while the fusion-literature assumes a self-absorption or reabsorption of cyclotron or synchrotron radiation emitted by the electrons spiraling along the magnetic field, the basic physics does not allow any effective reabsorption of cyclotron or synchrotron radiation. As is demonstrated, fallacious assumptions and notions, which somehow or other crept into the fusion-literature, are responsible for this discrepancy. In the present work, the theory is corrected. On the grounds of basic physics, a complete energy balance of magnetized and non-magnetized plasmas is presented for pulsed, stationary and self-sustaining operations by taking into account the energy release by reactions of light nuclei as well as different kinds of diffusive (conduction) and radiative (bremsstrahlung, cyclotron or synchrotron radiation and excitation radiation) energy losses. Already the energy losses by radiation make the energy balance negative. Hence, a fusion reactor - an energy producing device - seems to be beyond the realms of realization.

  16. Operating large controlled thermonuclear fusion research facilities

    SciTech Connect

    Gaudreau, M.P.J.; Tarrh, J.M.; Post, R.S.; Thomas, P.

    1987-10-01

    The MIT Tara Tandem Mirror is a large, state of the art controlled thermonuclear fusion research facility. Over the six years of its design, implementation, and operation, every effort was made to minimize cost and maximize performance by using the best and latest hardware, software, and scientific and operational techniques. After reviewing all major DOE fusion facilities, an independent DOE review committee concluded that the Tara operation was the most automated and efficient of all DOE facilities. This paper includes a review of the key elements of the Tara design, construction, operation, management, physics milestones, and funding that led to this success. We emphasize a chronological description of how the system evolved from the proposal stage to a mature device with an emphasis on the basic philosophies behind the implementation process. This description can serve both as a qualitative and quantitative database for future large experiment planning. It includes actual final costs and manpower spent as well as actual run and maintenance schedules, number of data shots, major system failures, etc. The paper concludes with recommendations for the next generation of facilities. 13 refs., 15 figs., 3 tabs.

  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. Senescence and quiescence induced compromised function in cultured macrophages.

    PubMed

    Holt, Dolly J; Grainger, David W

    2012-10-01

    Implants are predisposed to infection even years after implantation, despite ostensibly being surrounded by innumerable macrophages as part of the host foreign body response. The local implant environment could adversely influence the implant-associated macrophage phenotype, proliferative capacity, activation states, and ability to neutralize pathogens. This study monitored cultured macrophage proliferative states and phagocytotic competence on tissue culture plastic to address the hypothesis that extended contact with foreign materials alters macrophage phenotype. That such macrophage alterations might also occur around implants has significance to the foreign body response, infection, cancer, autoimmune and other diseases. Specifically, multiple indicators of macrophage proliferation in various culture conditions, including cell confluence, long-term culture (21 days), lipopolysaccharide (LPS) stimulation, passaging, and mitogenic stimulation are reported. Importantly, primary murine macrophages became quiescent at high confluence and senescent during long-term culture. Senescent macrophages significantly reduced their ability to phagocytose particles, while quiescent macrophages did not. Cell senescence and quiescence were not observed with repeated passaging. Primary macrophage stimulation with LPS delayed senescence but did not eliminate it. These results prompt the conclusion that both cell quiescence and senescence are observed under common macrophage culture conditions and could alter macrophage behavior and phenotypes in extended in vitro culture, such as the ability to phagocytose. Such macrophage transitions around foreign bodies in vivo are not documented: quiescence and senescence reported here in macrophage culture could be relevant to macrophage behavior both in vitro in bioassays and in vivo in the foreign body response and implant-centered infection.

  19. Thermonuclear model for x-ray transients

    SciTech Connect

    Wallace, R.K.; Woosley, S.E.; Weaver, T.A.

    1982-01-01

    The thermonuclear evolution of a 1.41 M sub solar neutron star accreting both solar and metal-deficient mixtures of hydrogen, helium, and heavy elements at rates ranging from about 10/sup -11/ to 10/sup -10/ M sub solar per year is examined using a one-dimensional numerical model. The metal deficient compositions may result either from placement of the neutron star in a binary system with a Population II red giant or from gravitational settling of heavy ions in the accreted material. For such accretion rates and metallicities, hydrogen burning, mediated by the ..beta..-limited CNO cycle, is stable and leads to the accumulation of a thick helium layer with mass 10/sup 23/ to 10/sup 25/ g and temperature 0.7 less than or equal to T/sub 8/ less than or equal to 1.2. Helium ignition occurs under extremely degenerate circumstances and is catastrophically violent. In the lower t helium shells this runaway is propagated as a convective deflagration, for the thicker layers a detonation front is set up which steepens into a strong relativistic shock wave in the neutron star envelope. In all models greatly super-Eddington luminosities in the outer layers of the neutron star lead to a sustained epoch of radiatively driven mass loss. Observationally, such models may correspond to rapid x-ray transients. The hopeless prospect for constructing a one-dimensional model for ..gamma..-ray bursts without magnetic field confinement is discussed and uncertainties pointed out in the strong screening correction for helium burning reaction.

  20. Pediatric restless legs syndrome: analysis of symptom descriptions and drawings.

    PubMed

    Picchietti, Daniel L; Arbuckle, Robert A; Abetz, Linda; Durmer, Jeffrey S; Ivanenko, Anna; Owens, Judith A; Croenlein, Jens; Allen, Richard P; Walters, Arthur S

    2011-11-01

    The specific aims of this study were to collect and analyze detailed symptom descriptions from patients with pediatric restless legs syndrome, ages 6 to 17 years, as well as assess symptom impact and the usefulness of drawings. Trained qualitative interviewers conducted face-to-face audio-recorded interviews of children and adolescents who met criteria for definite restless legs syndrome. Thirty-three patients in 3 age groups used 16 different categories of descriptors for restless legs sensations, with a mean of 3 or more categories used per patient in each age group. "Need to move/kick," "pain/hurts," "uncomfortable/cannot get comfortable," and "like bugs or ants/crawling" were the most common descriptors. Two-thirds reported daytime sensations, and nearly half had arm involvement. They described impact on sleep, cognitive function, and affect. Drawings provided useful diagnostic information. These detailed empirical data will be useful in clinical practice, as well as in the development of formal diagnostic tools and severity measures.

  1. 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.

  2. 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.

  3. 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.

  4. 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

    2003-01-01

    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. PMID:12446871

  5. 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

    2003-01-01

    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.

  6. 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…

  7. 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.

  8. Foxc1 reinforces quiescence in self-renewing hair follicle stem cells.

    PubMed

    Wang, Li; Siegenthaler, Julie A; Dowell, Robin D; Yi, Rui

    2016-02-01

    Stem cell quiescence preserves the cell reservoir by minimizing cell division over extended periods of time. Self-renewal of quiescent stem cells (SCs) requires the reentry into the cell cycle. In this study, we show that murine hair follicle SCs induce the Foxc1 transcription factor when activated. Deleting Foxc1 in activated, but not quiescent, SCs causes failure of the cells to reestablish quiescence and allows premature activation. Deleting Foxc1 in the SC niche of gene-targeted mice leads to loss of the old hair without impairing quiescence. In self-renewing SCs, Foxc1 activates Nfatc1 and bone morphogenetic protein (BMP) signaling, two key mechanisms that govern quiescence. These findings reveal a dynamic, cell-intrinsic mechanism used by hair follicle SCs to reinforce quiescence upon self-renewal and suggest a unique ability of SCs to maintain cell identity.

  9. Foxc1 reinforces quiescence in self-renewing hair follicle stem cells.

    PubMed

    Wang, Li; Siegenthaler, Julie A; Dowell, Robin D; Yi, Rui

    2016-02-01

    Stem cell quiescence preserves the cell reservoir by minimizing cell division over extended periods of time. Self-renewal of quiescent stem cells (SCs) requires the reentry into the cell cycle. In this study, we show that murine hair follicle SCs induce the Foxc1 transcription factor when activated. Deleting Foxc1 in activated, but not quiescent, SCs causes failure of the cells to reestablish quiescence and allows premature activation. Deleting Foxc1 in the SC niche of gene-targeted mice leads to loss of the old hair without impairing quiescence. In self-renewing SCs, Foxc1 activates Nfatc1 and bone morphogenetic protein (BMP) signaling, two key mechanisms that govern quiescence. These findings reveal a dynamic, cell-intrinsic mechanism used by hair follicle SCs to reinforce quiescence upon self-renewal and suggest a unique ability of SCs to maintain cell identity. PMID:26912704

  10. 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. PMID:27134503

  11. 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

  12. 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

  13. The Cellular Prion Protein: A Player in Immunological Quiescence

    PubMed Central

    Bakkebø, Maren K.; Mouillet-Richard, Sophie; Espenes, Arild; Goldmann, Wilfred; Tatzelt, Jörg; Tranulis, Michael A.

    2015-01-01

    Despite intensive studies since the 1990s, the physiological role of the cellular prion protein (PrPC) remains elusive. Here, we present a novel concept suggesting that PrPC contributes to immunological quiescence in addition to cell protection. PrPC is highly expressed in diverse organs that by multiple means are particularly protected from inflammation, such as the brain, eye, placenta, pregnant uterus, and testes, while at the same time it is expressed in most cells of the lymphoreticular system. In this paradigm, PrPC serves two principal roles: to modulate the inflammatory potential of immune cells and to protect vulnerable parenchymal cells against noxious insults generated through inflammation. Here, we review studies of PrPC physiology in view of this concept. PMID:26388873

  14. Phase portraits of the proliferation-quiescence decision.

    PubMed

    Zhang, Tongli

    2013-12-10

    Mammalian cells make the proliferation or quiescence decision at a specific point in the cell cycle called the restriction point, after which they become committed to proliferation and independent of growth factors for completion of mitosis. In the textbook view, this crucial transition occurs several hours after mitotic division (in the middle of G1 phase). In a Cell paper, Spencer et al. show that the restriction point should be defined not as a particular time point in G1 phase but in terms of the ON-OFF status of a bistable switch that emerges from the positive feedback in the CDK2-RB-E2F (cyclin-dependent kinase 2-retinoblastoma-E2F) interaction network. PMID:24327759

  15. 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

  16. On thermonuclear ignition criterion at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Batha, Steven H.

    2014-10-01

    Sustained thermonuclear fusion at the National Ignition Facility remains elusive. Although recent experiments approached or exceeded the anticipated ignition thresholds, the nuclear performance of the laser-driven capsules was well below predictions in terms of energy and neutron production. Such discrepancies between expectations and reality motivate a reassessment of the physics of ignition. We have developed a predictive analytical model from fundamental physics principles. Based on the model, we obtained a general thermonuclear ignition criterion in terms of the areal density and temperature of the hot fuel. This newly derived ignition threshold and its alternative forms explicitly show the minimum requirements of the hot fuel pressure, mass, areal density, and burn fraction for achieving ignition. Comparison of our criterion with existing theories, simulations, and the experimental data shows that our ignition threshold is more stringent than those in the existing literature and that our results are consistent with the experiments.

  17. 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.

  18. 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.

  19. 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.

  20. On thermonuclear ignition criterion at the National Ignition Facility

    SciTech Connect

    Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Batha, Steven H.

    2014-10-15

    Sustained thermonuclear fusion at the National Ignition Facility remains elusive. Although recent experiments approached or exceeded the anticipated ignition thresholds, the nuclear performance of the laser-driven capsules was well below predictions in terms of energy and neutron production. Such discrepancies between expectations and reality motivate a reassessment of the physics of ignition. We have developed a predictive analytical model from fundamental physics principles. Based on the model, we obtained a general thermonuclear ignition criterion in terms of the areal density and temperature of the hot fuel. This newly derived ignition threshold and its alternative forms explicitly show the minimum requirements of the hot fuel pressure, mass, areal density, and burn fraction for achieving ignition. Comparison of our criterion with existing theories, simulations, and the experimental data shows that our ignition threshold is more stringent than those in the existing literature and that our results are consistent with the experiments.

  1. 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

  2. Care of thermally injured victims of a thermonuclear explosion

    SciTech Connect

    Kaplan, J.Z.

    1983-04-29

    Nuclear war or accidental non-hostile nuclear explosion would obviously rank among the greatest disasters to affect mankind. In addition to massive numbers of casualties, depending on the circumstances, our ability to care for these casualties might also be affected. Despite the predictions of doomsday soothsayers, nothing is accomplished by burying one's head in the sand. Therefore, we must give consideration to how victims of a thermo-nuclear explosion would be cared for.

  3. Efficient GPU Accelerationfor Integrating Large Thermonuclear Networks in Astrophysics

    NASA Astrophysics Data System (ADS)

    Guidry, Mike

    2016-02-01

    We demonstrate the systematic implementation of recently-developed fast explicit kinetic integration algorithms on modern graphics processing unit (GPU) accelerators. We take as representative test cases Type Ia supernova explosions with extremely stiff thermonuclear reaction networks having 150-365 isotopic species and 1600-4400 reactions, assumed coupled to hydrodynamics using operator splitting. In such examples we demonstrate the capability to integrate independent thermonuclear networks from ~250-500 hydro zones (assumed to be deployed on CPU cores) in parallel on a single GPU in the same wall clock time that standard implicit methods can integrate the network for a single zone. This two or more orders of magnitude increase in efficiency for solving systems of realistic thermonuclear networks coupled to fluid dynamics implies that important coupled, multiphysics problems in various scientific and technical disciplines that were intractable, or could be simulated only with highly schematic kinetic networks, are now computationally feasible. As examples of such applications I will discuss our ongoing deployment of these new methods for Type Ia supernova explosions in astrophysics and for simulation of the complex atmospheric chemistry entering into weather and climate problems.

  4. 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.

  5. Augmentation in Restless Legs Syndrome: Treatment with Gradual Medication Modification.

    PubMed

    Rosenstein, Adam; Rabin, Marcie; Kurlan, Roger

    2015-01-01

    Dopaminergic drugs can cause augmentation during the treatment of restless legs syndrome (RLS). We previously reported that sudden withdrawal of dopaminergic treatment was poorly tolerated. We now report our experience with gradual withdrawal of the dopaminergic drug during the drug substitution process using a retrospective chart review with comparison to previous data. Seven patients with RLS and dopaminergic drug-induced augmentation were treated with a gradual withdrawal of the offending drug and replacement with an alternative medication. Compared to sudden withdrawal, measured outcomes were similar but gradual tapering was better tolerated. We conclude that for augmentation in RLS, gradual tapering of the augmentation-inducing dopaminergic drug is better tolerated than sudden withdrawal. The optimal approach to treating augmentation has not been established and may differ between patients. Further study with direct comparison of strategies and a larger patient population is needed to confirm our preliminary observations.

  6. Augmentation in Restless Legs Syndrome: Treatment with Gradual Medication Modification

    PubMed Central

    Rosenstein, Adam; Rabin, Marcie; Kurlan, Roger

    2015-01-01

    Dopaminergic drugs can cause augmentation during the treatment of restless legs syndrome (RLS). We previously reported that sudden withdrawal of dopaminergic treatment was poorly tolerated. We now report our experience with gradual withdrawal of the dopaminergic drug during the drug substitution process using a retrospective chart review with comparison to previous data. Seven patients with RLS and dopaminergic drug-induced augmentation were treated with a gradual withdrawal of the offending drug and replacement with an alternative medication. Compared to sudden withdrawal, measured outcomes were similar but gradual tapering was better tolerated. We conclude that for augmentation in RLS, gradual tapering of the augmentation-inducing dopaminergic drug is better tolerated than sudden withdrawal. The optimal approach to treating augmentation has not been established and may differ between patients. Further study with direct comparison of strategies and a larger patient population is needed to confirm our preliminary observations. PMID:26106453

  7. 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.

  8. 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

  9. Pramipexole induced psychosis in a patient with restless legs syndrome

    PubMed Central

    Signorelli, Maria S; Battaglia, Eliana; Costanzo, Maria C; Cannavò, Dario

    2013-01-01

    In the last few years, dopamine agonists (DA) have been used as first-line treatment for restless legs syndrome (RLS), a disabling sensorimotor disorder. Only recently have they reported some possible iatrogenic side effects, as shown below. The following case presents a RLS patient who developed hallucinatory and delusional symptoms with paranoid ideation after pramipexole assumption; these symptoms gradually decreased after pramipexole suspension and treatment by an oral antipsychotic therapy (quetiapine XR). Correlation between DAs assumption and psychotic symptoms is still not clear. The development of these side effects might be related to many risk factors such as genetic susceptibility, premorbid personality and psychosocial stressor; in order to minimise the risk of iatrogenic psychosis it could be useful to assess patients’ vulnerability factors selecting an alternative medication regime. PMID:24049088

  10. 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

  11. Incidence of Restless Legs Syndrome and Its Correlates

    PubMed Central

    Budhiraja, Pooja; Budhiraja, Rohit; Goodwin, James L.; Allen, Richard P.; Newman, Anne B.; Koo, Brian B.; Quan, Stuart F.

    2012-01-01

    Background: Restless legs syndrome (RLS) is a common sensorimotor disorder whose incidence is not known. The aim of the study was to determine the incidence and correlates of RLS in a population-based sample. Methods: We obtained data from the Tucson Cohort of the Sleep Heart Health Study, a prospective multicenter study. This cohort included 535 participants aged ≥ 40 years, who answered questions regarding RLS on the 2002 and 2006 sleep surveys. For this study, RLS was defined as the presence of all 4 International RLS Study Group criteria, with symptoms occurring ≥ 5 days/month and associated with at least moderate distress. Results: Mean age of the predominantly Caucasian (90.8%) participants on the 2002 survey was 59.8 ± 9.7 years; 52.2% were women. RLS prevalence was 4.1% in 2002 and 7.7% in 2006. The yearly incidence of RLS was 1.7% (6.6% over 4 years). Multivariate analyses demonstrated that estrogen use (OR = 2.5, 95% CI: 1.17-5.10) and self-reported obstructive lung disease (OR = 2.8, 95% CI: 1.37-5.83) were independent risk factors predicting incident RLS. Incident RLS was associated with higher prevalence of insomnia (26.5% vs. 7.6%, p = 0.001), increased sleepiness (38.2% vs. 22%, p = 0.036); and higher sleeping pill use in 2006 (23.5% vs. 9.7%, p = 0.019). Conclusion: The incidence of RLS in this population sample was 1.7% per year. Use of estrogen and history of obstructive lung disease were associated with a significantly higher incidence of RLS. RLS, in turn, was associated with insomnia and increased sleepiness. Citation: Budhiraja P; Budhiraja R; Goodwin JL; Allen RP; Newman AB; Koo BB; Quan SF. Incidence of restless legs syndrome and its correlates. J Clin Sleep Med 2012;8(2):119-124. PMID:22505854

  12. Willis-Ekbom Disease / Restless Legs Syndrome in the Elderly Population

    MedlinePlus

    ... Ekbom Disease/Restless Legs Syndrome in the Elderly Population A Guide To HelpYou Control and ManageYour WED/ ... more threatening for the elderly than the general population. Sleep loss or the use of some medications ...

  13. 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.

  14. Herschel Observations of Circinus X-1 during Outburst and Quiescence

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle; Fost, Tyler

    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. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. Gabapentin Enacarbil: A Review in Restless Legs Syndrome.

    PubMed

    Kim, Esther S; Deeks, Emma D

    2016-05-01

    Gabapentin enacarbil is an extended-release prodrug of gabapentin that is approved in the USA (Horizant(®)) and Japan (Regnite(®)) for the treatment of moderate to severe primary restless legs syndrome (RLS) in adults [featured indication]. This article summarizes pharmacological, efficacy and tolerability data relevant to the use of oral gabapentin enacarbil in this indication. In double-blind, multicentre trials, treatment with gabapentin enacarbil 600 mg/day for 12 weeks significantly improved the symptoms of moderate to severe primary RLS in adults. Gabapentin enacarbil also significantly improved RLS pain scores and generally improved sleep and mood outcomes. These data are supported by retrospective pooled analyses of three of these trials (XP081, PIVOT RLS I and PIVOT RLS II), with gabapentin enacarbil generally improving symptoms irrespective of disease severity, associated sleep disturbance or prior dopamine agonist use. Responses to gabapentin enacarbil were sustained in longer-term trials, with lower relapse rates in gabapentin enacarbil than placebo recipients in a longer-term maintenance study. Overall, in short and longer-term trials, relatively few patients discontinued treatment, adverse events were mostly mild to moderate in severity, and somnolence/sedation and dizziness were the most commonly reported adverse events. Notably, there were no reports of augmentation or QT-interval prolongation. Gabapentin enacarbil is an important agent for the treatment of adults with moderate to severe primary RLS.

  4. Does domperidone potentiate mirtazapine-associated restless legs syndrome?

    PubMed

    Chang, Chuan-Chia; Shiah, I-Shin; Chang, Hsin-An; Mao, Wei-Chung

    2006-03-01

    There is now evidence to suggest a central role for the dopaminergic system in restless legs syndrome (RLS). For example, the symptoms of RLS can be dramatically improved by levodopa and dopamine agonists, whereas central dopamine D2 receptor antagonists can induce or aggravate RLS symptoms. To our knowledge, there is no previous report regarding whether domperidone, a peripheral dopamine D2 receptor antagonist, can also induce or aggravate symptoms of RLS. Mirtazapine, the first noradrenergic and specific serotonergic antidepressant (NaSSA), has been associated with RLS in several recent publications. The authors report here a depressed patient comorbid with postprandial dyspepsia who developed RLS after mirtazapine had been added to his domperidone therapy. Our patient started to have symptoms of RLS only after he had been treated with mirtazapine, and his RLS symptoms resolved completely upon discontinuation of his mirtazapine. Such a temporal relationship between the use of mirtazapine and the symptoms of RLS in our patient did not support a potentiating effect of domperione on mirtazapine-associated RLS. However, physicians should be aware of the possibility that mirtazapine can be associated with RLS in some individuals, especially those receiving concomitant dopamine D2 receptor antagonists. PMID:16309808

  5. 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

  6. Daytime dysfunction in children with restless legs syndrome.

    PubMed

    Furudate, Naomichi; Komada, Yoko; Kobayashi, Mina; Nakajima, Shun; Inoue, Yuichi

    2014-01-15

    We investigated daytime dysfunction in children with restless legs syndrome (RLS) and the effects of treatment primarily with iron supplements on RLS symptoms and daytime dysfunction. We recruited 25 children with RLS (male:female=6:19, mean age at study onset: 12.3 years) for this prospective study, assessing their demographics, symptomatic characteristics, serum ferritin levels, and daytime functioning using the ADHD Rating Scale IV (ADHD-RS-IV), the Pediatric Symptom Checklist (PSC), and the Pediatric Quality of Life Inventory (PedsQL™). Children with RLS were compared with 28 controls (male:female=10:18, mean age: 13.2 years) on these measures, pre- and post-treatment. Before treatment, ADHD-RS-IV (all ps<0.05) and PSC scores (p<0.05) were significantly higher and PedsQL™ scores (all ps<0.05) significantly lower in the RLS group than in the control group. Eight and one of the RLS group had abnormally high PSC and ADHD-RS-IV scores, respectively. Following treatment, participants' daytime function had improved to levels similar to those of controls. Sixteen out of twenty-three cases were successfully treated primarily with iron supplement. Some children with RLS have daytime dysfunction; however, this can be treated with iron supplements. PMID:24360552

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. An artificial niche preserves the quiescence of muscle stem cells and enhances their therapeutic efficacy.

    PubMed

    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

    2016-07-01

    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 culture. Here we describe an artificial niche 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 engineered muscle fibers that mimic the native myofiber of the MuSC niche. Mouse MuSCs maintained in QM on engineered fibers showed enhanced potential for engraftment, tissue regeneration and self-renewal after transplantation in mice. An artificial niche adapted to human cells similarly extended the quiescence of human MuSCs in vitro and enhanced their potency in vivo. Our approach for maintaining quiescence may be applicable to stem cells isolated from other tissues. PMID:27240197

  12. 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.

  13. 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.

  14. Return to quiescence of mouse neural stem cells by degradation of a proactivation protein.

    PubMed

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

    2016-07-15

    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 destabilizes proactivation 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 proactivation factor. PMID:27418510

  15. 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

  16. 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.

  17. 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.

  18. NASA superconducting magnetic mirror facility. [for thermonuclear research

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Swanson, M. C.; Nichols, C. R.; Bloy, S. J.; Nagy, L. A.; Brady, F. J.

    1973-01-01

    The design details and initial test results of a superconducting magnetic mirror facility that has been constructed at NASA Lewis Research Center for use in thermonuclear research are summarized. The magnet system consists of four solenoidal coils which are individually rated at 5.0 T. Each coll is composed of an inner, middle, and outer winding. The inner winding is wound of stabilized Nb3Sn superconducting ribbon, and the middle and outer windings are wound of stabilized Nb-Ti superconducting wire. When arranged in the mirror geometry, the four coils will produce 8.7 T at the mirrors and a 1.8 mirror ratio. The magnet has a 41-cm diameter clear bore which is open to atmosphere. Distance between the mirrors is 111 cm. Presently there are only three magnets in the facility; the fourth magnet is being rebuilt.

  19. A compilation of charged-particle induced thermonuclear reaction rates

    NASA Astrophysics Data System (ADS)

    Angulo, C.; Arnould, M.; Rayet, M.; Descouvemont, P.; Baye, D.; Leclercq-Willain, C.; Coc, A.; Barhoumi, S.; Aguer, P.; Rolfs, C.; Kunz, R.; Hammer, J. W.; Mayer, A.; Paradellis, T.; Kossionides, S.; Chronidou, C.; Spyrou, K.; degl'Innocenti, S.; Fiorentini, G.; Ricci, B.; Zavatarelli, S.; Providencia, C.; Wolters, H.; Soares, J.; Grama, C.; Rahighi, J.; Shotter, A.; Lamehi Rachti, M.

    1999-08-01

    Low-energy cross section data for 86 charged-particle induced reactions involving light (1 <=Z <=14), mostly stable, nuclei are compiled. The corresponding Maxwellian-averaged thermonuclear reaction rates of relevance in astrophysical plasmas at temperatures in the range from 106 K to 1010 K are calculated. These evaluations assume either that the target nuclei are in their ground state, or that the target states are thermally populated following a Maxwell-Boltzmann distribution, except in some cases involving isomeric states. Adopted values complemented with lower and upper limits of the rates are presented in tabular form. Analytical approximations to the adopted rates, as well as to the inverse/direct rate ratios, are provided.

  20. Hot subdwarf stars and their connection to thermonuclear supernovae

    NASA Astrophysics Data System (ADS)

    Geier, S.; Kupfer, T.; Ziegerer, E.; Heber, U.; Németh, P.; Irrgang, A.; pre=", team

    2016-07-01

    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 crossmatching known sdB stars with proper motion and light curve catalogues. The Gaia mission will provide accurate astrometry and light curves of all the stars in our hot subdwarf sample and will allow us to compile a much larger all-sky catalogue of those stars. In this way we expect to find hundreds of progenitor binaries and ejected companions.

  1. 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.

  2. 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

  3. 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.

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

    DOE PAGES

    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.; et al

    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

  5. Detonating Failed Deflagration Model of Thermonuclear Supernovae. I. Explosion Dynamics

    NASA Astrophysics Data System (ADS)

    Plewa, Tomasz

    2007-03-01

    We present a detonating failed deflagration model of Type Ia supernovae. In this model, the thermonuclear explosion of a massive white dwarf follows an off-center deflagration. We conduct a survey of asymmetric ignition configurations initiated at various distances from the stellar center. In all cases studied, we find that only a small amount of stellar fuel is consumed during deflagration phase, no explosion is obtained, and the released energy is mostly wasted on expanding the progenitor. Products of the failed deflagration quickly reach the stellar surface, polluting and strongly disturbing it. These disturbances eventually evolve into small and isolated shock-dominated regions that are rich in fuel. We consider these regions as seeds capable of forming self-sustained detonations that, ultimately, result in the thermonuclear supernova explosion. Preliminary nucleosynthesis results indicate that the model supernova ejecta are typically composed of about 0.1-0.25 Msolar of silicon group elements and 0.9-1.2 Msolar of iron group elements and are essentially carbon-free. The ejecta have a composite morphology, are chemically stratified, and display a modest amount of intrinsic asymmetry. The innermost layers are slightly egg shaped with the axis ratio ~1.2-1.3 and dominated by the products of silicon burning. This central region is surrounded by a shell of silicon group elements. The outermost layers of ejecta are highly inhomogeneous and contain products of incomplete oxygen burning with only small admixture of unburned stellar material. The explosion energies are ~(1.3-1.5)×1051 ergs.

  6. 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.

  7. 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

  8. 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

  9. 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. PMID:27523456

  10. Risk of Restless Legs Syndrome Following Tension-Type Headache

    PubMed Central

    Yang, Fu-Chi; Lin, Te-Yu; Chen, Hsuan-Ju; Lee, Jiunn-Tay; Lin, Chun-Chieh; Kao, Chia-Hung

    2015-01-01

    Abstract Migraine and restless legs syndrome (RLS) appear to be associated, but the relationship between tension-type headache (TTH) and RLS is unknown. This nationwide, population-based, retrospective cohort study explored the potential association between TTH and RLS. We identified 15,504 patients with newly diagnosed TTH from 2000 to 2007 and 62,016 individuals without TTH who were selected by frequency matched based on sex, age, and the index year. The study participants were followed until diagnosed with RLS, withdrawal from the NHI program, or the end of 2011. Cox proportional hazard models were used to identify risk factors for RLS in TTH patients. After adjusting for sex, age, comorbidity, and medications, TTH was significantly associated with an increased risk of RLS (hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.22–2.02). The risk was most prominent in patients aged 20 to 39 years in the TTH group, which exhibited a 2.60-fold higher risk (95% confidence interval = 1.53–4.42) of RLS compared with the non-TTH group. The TTH group had a higher risk of RLS than that of the non-TTH group regardless of sex. Tension-type headache appears to be associated with an increased risk of developing RLS. This similarity to migraines may indicate that headache and RLS have a coincident pathophysiological mechanism, a possibility requiring further study. Clinicians should be more attentive to RLS as a possible comorbidity in patients with TTH. PMID:26579827

  11. Increased Risk of Restless Legs Syndrome in Patients With Migraine

    PubMed Central

    Yang, Fu-Chi; Lin, Te-Yu; Chen, Hsuan-Ju; Lee, Jiunn-Tay; Lin, Chun-Chieh; Huang, Wen-Yen; Chen, Hsin-Hung; Kao, Chia-Hung

    2016-01-01

    Abstract Previous studies suggest that an association between restless legs syndrome (RLS) and migraine exists. However, population-based data are unavailable in Asian cohorts. Our study thus aims to evaluate the association between migraine and RLS in a nationwide, population-based cohort in Taiwan and to examine the effects of age, sex, migraine subtype, and comorbidities on RLS development. Data from the Taiwan National Health Insurance Research Database were used. Patients aged 20 years or older with newly diagnosed migraine from 2000 to 2008 were included; 23,641 patients with newly diagnosed migraine and 94,564 subjects without migraine were randomly selected and followed until RLS development, withdrawal from the National Health Insurance, or until the end of 2011. A multivariate Cox proportional hazards regression model was used to explore the risk of RLS in patients with migraine after adjustment for demographic characteristics and comorbidities. Both cohorts were followed for a mean of 7.38 years. After adjustment for covariates, the risk of RLS was 1.42-fold higher (95% confidence interval = 1.13–1.79) in the migraine cohort than in the nonmigraine cohort (7.19 versus 3.42 years per 10,000 person-years). The increased risk was more prominent in males in the migraine cohort (1.87-fold increased risk, 95% confidence interval 1.22–2.85). Neither comorbidity status nor migraine subtype influenced the RLS risk. This population-based study demonstrated that migraine is associated with an increased risk of RLS compared with those without migraine, particularly in male patients with migraine and regardless of the comorbidity status. PMID:26844484

  12. Serum endocan levels in women with restless legs syndrome

    PubMed Central

    Celik, Kenan; Cikrikcioglu, Mehmet A; Halac, Gulistan; Kilic, Elif; Ayhan, Siddika; Ozaras, Nihal; Yildiz, Kemal; Yildiz, Rabia S; Zorlu, Mehmet; Karatoprak, Cumali; Cakirca, Mustafa; Kiskac, Muharrem

    2015-01-01

    Background Endocan is a recently introduced marker of endothelial dysfunction. The objective of this study was to compare serum endocan levels in patients with restless legs syndrome (RLS) and control subjects in order to elucidate whether RLS is associated with endothelial dysfunction. Methods A total of 31 drug naïve female patients with RLS and 31 age- and BMI-matched women were included in the study. Patients with pathological or physiological conditions or with a history of medication use that could potentially influence endothelial functions were excluded, as well as those with alcohol or drug abuse history. The two groups were compared with routine blood tests and serum endocan levels. Results Patients with RLS had lower serum endocan levels than the controls (P=0.037). There was a negative bivariate correlation between RLS severity score and serum endocan levels (r=−0.406, P=0.023). While white blood cell count was significantly higher in RLS group, 25-hydroxy vitamin D3, vitamin B12, transferrin saturation rate, and HDL-cholesterol were significantly lower. Creatininemia and diastolic blood pressure were also marginally insignificantly lower in RLS group. Due to the presence of differences between two groups in these variables, a linear regression analysis was performed that showed a positive association between endocan and creatininemia (β=0.310, P=0.022), and a negative association between endocan and RLS (β=−0.502, P<0.001). Conclusion The results of this study seem to suggest that patients with RLS may have better endothelial functions when compared with the general population and that these patients may be better protected against atherosclerosis. PMID:26640378

  13. 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

  14. Sleep disorders: A review of the interface between restless legs syndrome and iron metabolism.

    PubMed

    Daubian-Nosé, Paulo; Frank, Miriam K; Esteves, Andrea Maculano

    2014-12-01

    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

  15. 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

  16. 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…

  17. MULTIWAVELENGTH OBSERVATIONS OF A0620-00 IN QUIESCENCE

    SciTech Connect

    Froning, Cynthia S.; France, Kevin; Khargharia, Juthika; and others

    2011-12-10

    than the former, indicating that {approx}90% of the accreted mass must be lost from the system if the predictions of the disk instability model and the estimated interoutburst interval are correct. The mass accretion rate at the hot spot is 10{sup 5} the accretion rate at the black hole inferred from the X-ray luminosity. To reconcile these requires that outflows carry away virtually all of the accreted mass, a very low rate of mass transfer from the outer cold disk into the inner hot region, and/or radiatively inefficient accretion. We compared our broadband SED to two models of A0620-00 in quiescence: the advection-dominated accretion flow model and the maximally jet-dominated model. The comparison suggests that strong outflows may be present in the system, indicated by the discrepancies in accretion rates and the FUV upturn in flux in the SED.

  18. 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

  19. Melatonin reduces migratory restlessness in Sylvia warblers during autumnal migration

    PubMed Central

    2013-01-01

    Introduction A remarkable aspect of bird migration is its nocturnality, particularly common in Passeriformes. The switch in activity from purely diurnal to also nocturnal is evident even in caged birds that during migratory periods develop an intense nocturnal restlessness, termed Zugunruhe. The mechanisms that control this major change in activity are mostly unknown. Previous work with Sylvia warblers suggested an involvement of melatonin, a hormone associated with day-night cycles in most vertebrates. In a recent study we found no effects of melatonin administration on Zugunruhe during spring migration. However, previous studies indicated that the response to melatonin manipulation could differ between spring and autumn migration, which are in fact separate life history stages. Here we tested whether a non-invasive treatment with melatonin can alter Zugunruhe in wild garden warblers S. borin and blackcaps S. atricapilla subject to temporary captivity at an autumnal stopover site. Food availability in the cage (yes/no) was added as a second factor because previous work showed that it enhanced Zugunruhe. Results The melatonin treatment significantly decreased the amount of Zugunruhe, while the availability of food only tended to increase the amount of Zugunruhe. Fuel deposits also had a strong effect on the amount of nocturnal activity: lean birds with a fat score of 1 showed significantly less Zugunruhe than fatter birds. The change in body mass during the time spent in the recording cage depended on food availability, but not on any of the other factors. Conclusions This study shows that the migratory programme of two Sylvia warblers can be manipulated by administration of exogenous melatonin and confirms that this hormone is involved in the control of migratory behaviour. To our knowledge, this is one of the first demonstrations that the autumn migratory programme can be altered by hormonal manipulation in migrating birds. The comparison with a similar study

  20. Cryogenic thermonuclear fuel implosions on the National Ignition Facility

    SciTech Connect

    Glenzer, S. H.; Callahan, D. A.; MacKinnon, A. J.; Alger, E. T.; Berger, R. L.; Bernstein, L. A.; Bleuel, D. L.; Bradley, D. K.; Burkhart, S. C.; Burr, R.; Caggiano, J. A.; Castro, C.; Choate, C.; Clark, D. S.; Celliers, P.; Cerjan, C. J.; Collins, G. W.; Dewald, E. L.; DiNicola, P.; DiNicola, J. M.; and others

    2012-05-15

    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 {mu}m 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) {mu}m, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 {+-} 0.09) g cm{sup -2} result in fuel densities approaching 600 g cm{sup -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 10{sup 15} that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5{+-}0.1) Multiplication-Sign 10{sup 14} 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Proliferation/Quiescence: When to start? Where to stop? What to stock?

    PubMed Central

    2011-01-01

    The cell cycle is a tightly controlled series of events that ultimately lead to cell division. The literature deciphering the molecular processes involved in regulating the consecutive cell cycle steps is colossal. By contrast, much less is known about non-dividing cellular states, even if they concern the vast majority of cells, from prokaryotes to multi-cellular organisms. Indeed, cells decide to enter the division cycle only if conditions are favourable. Otherwise they may enter quiescence, a reversible non-dividing cellular state. Recent studies in yeast have shed new light on the transition between proliferation and quiescence, re-questioning the notion of cell cycle commitment. They also indicate a predominant role for cellular metabolic status as a major regulator of quiescence establishment and exit. Additionally, a growing body of evidence indicates that environmental conditions, and notably the availability of various nutrients, by impinging on specific metabolic routes, directly regulate specific cellular re-organization that occurs upon proliferation/quiescence transitions. PMID:22152110

  6. 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. PMID:20535374

  7. 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

  8. 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.

  9. 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.

  10. 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}.

  11. Thermonuclear inverse magnetic pumping power cycle for stellarator reactors

    NASA Astrophysics Data System (ADS)

    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 stellerator 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.

  12. 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.

  13. Cryogenic thermonuclear fuel implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Glenzer, Siegfried

    2011-10-01

    The first inertial confinement fusion implosion experiments with cryogenic fuel layers have been fielded in preparation for ignition experiments on the National Ignition Facility. These experiments use mega joule laser energies that compress fusion capsules in indirect dive hohlraums to test initial hot spot formation and thermonuclear fuel assembly. Hydrogen-rich fuel (THD) provides a relatively low yield and diagnostics rich environment that allows us to measure the implosion core, neutron yield, temperatures and fuel areal density from a suite of x-ray and neutron diagnostics. These experiments have successfully demonstrated the control of the implosion shape using ignition grade cryogenic fuel layers, laser pulse shaping, and nonlinear plasma optics. The implosions show scaling of the DT fusion yield with ion temperature over more than one order of magnitude to a yield in excess of 1014 neutrons. Recent implosion performance improvements due to shock timing tuning have led to high Lawson confinement parameters. Additional tuning experiments are being performed with the goal to increase hot spot temperatures and to observe alpha particle heating with pure DT fuel. Prepared by LLNL under Contract DE-AC52-07NA27344.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. A microRNA network regulates proliferative timing and extracellular matrix synthesis during cellular quiescence in fibroblasts

    PubMed Central

    2012-01-01

    Background Although quiescence (reversible cell cycle arrest) is a key part in the life history and fate of many mammalian cell types, the mechanisms of gene regulation in quiescent cells are poorly understood. We sought to clarify the role of microRNAs as regulators of the cellular functions of quiescent human fibroblasts. Results Using microarrays, we discovered that the expression of the majority of profiled microRNAs differed between proliferating and quiescent fibroblasts. Fibroblasts induced into quiescence by contact inhibition or serum starvation had similar microRNA profiles, indicating common changes induced by distinct quiescence signals. By analyzing the gene expression patterns of microRNA target genes with quiescence, we discovered a strong regulatory function for miR-29, which is downregulated with quiescence. Using microarrays and immunoblotting, we confirmed that miR-29 targets genes encoding collagen and other extracellular matrix proteins and that those target genes are induced in quiescence. In addition, overexpression of miR-29 resulted in more rapid cell cycle re-entry from quiescence. We also found that let-7 and miR-125 were upregulated in quiescent cells. Overexpression of either one alone resulted in slower cell cycle re-entry from quiescence, while the combination of both together slowed cell cycle re-entry even further. Conclusions microRNAs regulate key aspects of fibroblast quiescence including the proliferative state of the cells as well as their gene expression profiles, in particular, the induction of extracellular matrix proteins in quiescent fibroblasts. PMID:23259597

  19. Intrinsically restless: Unifying science, writing, and the human condition

    NASA Astrophysics Data System (ADS)

    Sissom, Matthew

    The field of physics has always fascinated me, but I never possessed the mathematical skills necessary to extend that interest past the point of curiosity. This thesis was set up to explore how I and other writers, specifically Walt Whitman, use(d) the skills we do have to ask and attempt to answer the same cosmic questions normally reserved for scientists overseeing particle collider experiments. In Tao of Physics, Fritjof Capra attempted to blend the principles of Eastern philosophy with the movements associated with modern physics. In doing so, he offers up a few insights into the human desire to "divide the world into separate objects and events" (117), which I believe, when it comes to fiction, greatly influences the audience's interpretive framework. Capra suggests, "To believe that our abstract concepts of separate `things' and `vents' are realities of nature is an illusion" (117). Humans use this division to cope with our everyday environment, yet it is not a fundamental feature of reality but, rather, an abstraction devised by our discriminating and categorizing intellect. It is a coping mechanism, as Capra refers to it, that pins writers in a corner, encouraging them to forms and styles set by their predecessors to better satisfy the "discriminating and categorizing intellect" of their audience. Writers often struggle to achieve a balance between accurately presenting the human condition that, like Capra's description of subatomic particles as "intrinsically restless" (117), changes based on myriad variables and properly structuring their writing to fit a predetermined model. Whitman, a fan of popular science, drew from the scientific world, using his understanding of the interpretive framework, to better craft his poems' metaphors. In "Song of Myself," Whitman suggests that the celebration of one's own existence cannot be separated from the celebration of the universe, "For every atom belonging to me as good belongs to you" (1-3). Whitman's writing

  20. 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

  1. 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

  2. Neighbourhood disadvantage, network capital and restless sleep: is the association moderated by gender in urban-dwelling adults?

    PubMed

    Bassett, Emma; Moore, Spencer

    2014-05-01

    Despite evidence suggesting that social and neighbourhood contexts may relate to sleep in adults, the underlying social and demographic mechanisms involved remain relatively unexplored. This study proposes a conceptual framework for examining the link between social environments and restless sleep, and assesses whether associations among restless sleep, social capital, and neighbourhood environments differ by gender. Data come from the 2008 Montreal Neighborhood Networks and Healthy Aging Study (n = 2707). Participants self-reported restless sleep. Network and cognitive dimensions of social capital were examined. Neighbourhood disadvantage and population density were measured using 2006 Canada Census data. Multilevel logistic analyses adjusting for socio-economic and -demographic variables were used to estimate associations among study variables. The final sample size for this study was 2643 adults (nmen = 930; nwomen = 1713). Women were more likely to experience restless sleep than men (OR: 1.29; 95% CIs: 1.07, 1.55). Network capital increased the likelihood of restless sleep in men (OR = 1.25; 95% CI: 1.04-1.50) but not women. High generalized trust decreased the odds of restless sleep in women (OR = 0.75; 95% CI: 0.59-0.94); neighbourhood disadvantage increased the odds of restless sleep in women but not men (OR = 1.18; 95% CI: 1.01-1.38). The association among restless sleep, social capital, and neighbourhood environmental factors differed in male and female Montreal adults. This study contributes to a greater understanding of possible differential associations between social environments and health in men and women. Greater knowledge of the social and environmental factors that contribute to poor sleep in men and women can aid in the design of interventions to improve sleep patterns in the general population. Social and health promotion interventions might aim to improve general neighbourhood environmental conditions to improve the sleep health of

  3. Thermonuclear Fusion Research Progress and the Way to the Reactor

    NASA Astrophysics Data System (ADS)

    Koch, Raymond

    2006-06-01

    The paper reviews the progress of fusion research and its prospects for electricity generation. It starts with a reminder of the principles of thermonuclear fusion and a brief discussion of its potential role in the future of the world energy production. The reactions allowing energy production by fusion of nuclei in stars and on earth and the conditions required to sustain them are reviewed. At the high temperatures required for fusion (hundred millions kelvins), matter is completely ionized and has reached what is called its 4th state: the plasma state. The possible means to achieve these extreme temperatures is discussed. The remainder of the paper focuses on the most promising of these approaches, magnetic confinement. The operating principles of the presently most efficient machine of this type — the tokamak — is described in some detail. On the road to producing energy with fusion, a number of obstacles have to be overcome. The plasma, a fluid that reacts to electromagnetic forces and carries currents and charges, is a complex medium. Fusion plasma is strongly heated and is therefore a good example of a system far from equilibrium. A wide variety of instabilities can grow in this system and lead to self-organized structures and spontaneous cycles. Turbulence is generated that degrades the confinement and hinders easy achievement of long lasting hot plasmas. Physicists have learned how to quench turbulence, thereby creating sort of insulating bottles inside the plasma itself to circumvent this problem. The recent history of fusion performance is outlined and the prospect of achieving power generation by fusion in a near future is discussed in the light of the development of the "International Tokamak Experimental Reactor" project ITER.

  4. Tuberous sclerosis complex 1 (Tsc1) enforces quiescence of naive T cells to promote immune homeostasis and function

    PubMed Central

    Yang, Kai; Neale, Geoffrey; Green, Douglas R.; He, Weifeng; Chi, Hongbo

    2011-01-01

    The mechanisms that regulate T cell quiescence are poorly understood. We report that tuberous sclerosis complex 1 (Tsc1) establishes a quiescence program in naive T cells by controlling cell size, cell cycle entry, and responses to T cell receptor stimulation. Loss of quiescence predisposed Tsc1-deficient T cells to apoptosis that resulted in loss of conventional T cells and invariant natural killer T cells. Loss of Tsc1 function dampened in vivo immune responses to bacterial infection. Tsc1-deficient T cells exhibited increased mTORC1 but diminished mTORC2 activities, with mTORC1 activation essential for the disruption of immune homeostasis. Therefore, Tsc1-dependent control of mTOR is crucial in establishing naive T cell quiescence to facilitate adaptive immune function. PMID:21765414

  5. Regulation of glycolysis by Pdk functions as a metabolic checkpoint for cell cycle quiescence in hematopoietic stem cells.

    PubMed

    Takubo, Keiyo; Nagamatsu, Go; Kobayashi, Chiharu I; Nakamura-Ishizu, Ayako; Kobayashi, Hiroshi; Ikeda, Eiji; Goda, Nobuhito; Rahimi, Yasmeen; Johnson, Randall S; Soga, Tomoyoshi; Hirao, Atsushi; Suematsu, Makoto; Suda, Toshio

    2013-01-01

    Defining the metabolic programs that underlie stem cell maintenance will be essential for developing strategies to manipulate stem cell capacity. Mammalian hematopoietic stem cells (HSCs) maintain cell cycle quiescence in a hypoxic microenvironment. It has been proposed that HSCs exhibit a distinct metabolic phenotype under these conditions. Here we directly investigated this idea using metabolomic analysis and found that HSCs generate adenosine-5'-triphosphate by anaerobic glycolysis through a pyruvate dehydrogenase kinase (Pdk)-dependent mechanism. Elevated Pdk expression leads to active suppression of the influx of glycolytic metabolites into mitochondria. Pdk overexpression in glycolysis-defective HSCs restored glycolysis, cell cycle quiescence, and stem cell capacity, while loss of both Pdk2 and Pdk4 attenuated HSC quiescence, glycolysis, and transplantation capacity. Moreover, treatment of HSCs with a Pdk mimetic promoted their survival and transplantation capacity. Thus, glycolytic metabolic status governed by Pdk acts as a cell cycle checkpoint that modulates HSC quiescence and function. PMID:23290136

  6. 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

  7. 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.

  8. Following a black hole X-ray transient as it transitions to quiescence

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard

    2013-09-01

    There is increasing evidence that the quiescent state of black hole X-ray binaries (BHXBs) is different from the canonical hard state at higher luminosities. Quiescent BHXB X-ray spectra are generally softer, and it has recently been realized that not every system takes the same path through the radio-X-ray luminosity plane during the decay into quiescence. We request six (nearly) simultaneous Chandra/VLA TOO observations to monitor a BHXB during an outburst decay between 3e-7 -- 1e-4 L_edd, a crucial luminosity regime that represents the transition into quiescence for many systems, but still has sparse data coverage. From these coordinated observations we will place new constraints on jet-dominated and radiatively inefficient accretion flow models.

  9. Following a black hole X-ray transient through the transition into quiescence

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard

    2014-09-01

    There is increasing evidence that the quiescent state of black hole X-ray binaries (BHXBs) is different from the canonical hard state at higher luminosities. Quiescent BHXB X-ray spectra are generally softer, and it has recently been realized that not every system takes the same path through the radio/X-ray luminosity plane during the decay into quiescence. We request six simultaneous Chandra/VLA TOO observations to monitor a BHXB during an outburst decay between 3e-7--1e-4 L_Edd, a crucial luminosity regime that represents the transition into quiescence for many systems, but still has sparse data coverage. From these coordinated observations we will place new constraints on jet-dominated and radiatively inefficient accretion flow models.

  10. 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

  11. A SCARECROW-RETINOBLASTOMA Protein Network Controls Protective Quiescence in the Arabidopsis Root Stem Cell Organizer

    PubMed Central

    Wachsman, Guy; Du, Yujuan; Arteága-Vázquez, Mario; Zhang, Hongtao; Benjamins, Rene; Blilou, Ikram; Neef, Anne B.; Chandler, Vicki; Scheres, Ben

    2013-01-01

    Quiescent long-term somatic stem cells reside in plant and animal stem cell niches. Within the Arabidopsis root stem cell population, the Quiescent Centre (QC), which contains slowly dividing cells, maintains surrounding short-term stem cells and may act as a long-term reservoir for stem cells. The RETINOBLASTOMA-RELATED (RBR) protein cell-autonomously reinforces mitotic quiescence in the QC. RBR interacts with the stem cell transcription factor SCARECROW (SCR) through an LxCxE motif. Disruption of this interaction by point mutation in SCR or RBR promotes asymmetric divisions in the QC that renew short-term stem cells. Analysis of the in vivo role of quiescence in the root stem cell niche reveals that slow cycling within the QC is not needed for structural integrity of the niche but allows the growing root to cope with DNA damage. PMID:24302889

  12. Relationship between accelerating seismicity and quiescence, two precursors to large earthquakes

    NASA Astrophysics Data System (ADS)

    Mignan, Arnaud; Di Giovambattista, Rita

    2008-08-01

    The Non-Critical Precursory Accelerating Seismicity Theory (PAST) has been proposed recently to explain the formation of accelerating seismicity (increase of the a-value) observed before large earthquakes. In particular, it predicts that precursory accelerating seismicity should occur in the same spatiotemporal window as quiescence. In this first combined study we start by determining the spatiotemporal extent of quiescence observed prior to the 1997 Mw = 6 Umbria-Marche earthquake, Italy, using the RTL (Region-Time-Length) algorithm. We then show that background events located in that spatiotemporal window form a clear acceleration, as expected by the Non-Critical PAST. This result is a step forward in the understanding of precursory seismicity by relating two of the principal patterns that can precede large earthquakes

  13. 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.

  14. Reversible Age-Related Phenotypes Induced during Larval Quiescence in C. elegans.

    PubMed

    Roux, Antoine E; Langhans, Kelley; Huynh, Walter; Kenyon, Cynthia

    2016-06-14

    Cells can enter quiescent states in which cell cycling and growth are suspended. We find that during a long developmental arrest (quiescence) induced by starvation, newly hatched C. elegans acquire features associated with impaired proteostasis and aging: mitochondrial fission, ROS production, protein aggregation, decreased proteotoxic-stress resistance, and at the organismal level, decline of mobility and high mortality. All signs of aging but one, the presence of protein aggregates, were reversed upon return to development induced by feeding. The endoplasmic reticulum receptor IRE-1 is completely required for recovery, and the downstream transcription factor XBP-1, as well as a protein kinase, KGB-1, are partially required. Interestingly, kgb-1(-) mutants that do recover fail to reverse aging-like mitochondrial phenotypes and have a short adult lifespan. Our study describes the first pathway that reverses phenotypes of aging at the exit of prolonged quiescence. PMID:27304510

  15. 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.

  16. CHD7 maintains neural stem cell quiescence and prevents premature stem cell depletion in the adult hippocampus.

    PubMed

    Jones, Kieran M; Sarić, Nemanja; Russell, John P; Andoniadou, Cynthia L; Scambler, Peter J; Basson, M Albert

    2015-01-01

    Neural stem/progenitor cells (NSCs) in the hippocampus produce new neurons throughout adult life. NSCs are maintained in a state of reversible quiescence and the failure to maintain the quiescent state can result in the premature depletion of the stem cell pool. The epigenetic mechanisms that maintain this quiescent state have not been identified. Using an inducible knockout mouse model, we show that the chromatin remodeling factor chromodomain-helicase-DNA-binding protein 7 (CHD7) is essential for maintaining NSC quiescence. CHD7 inactivation in adult NSCs results in a loss of stem cell quiescence in the hippocampus, a transient increase in cell divisions, followed by a significant decline in neurogenesis. This loss of NSC quiescence is associated with the premature loss of NSCs in middle-aged mice. We find that CHD7 represses the transcription of several positive regulators of cell cycle progression and is required for full induction of the Notch target gene Hes5 in quiescent NSCs. These findings directly link CHD7 to pathways involved in NSC quiescence and identify the first chromatin-remodeling factor with a role in NSC quiescence and maintenance. As CHD7 haplo-insufficiency is associated with a range of cognitive disabilities in CHARGE syndrome, our observations may have implications for understanding the basis of these deficits.

  17. Te Kapunga Putohe (the restless hands): a Maori centred nursing practice model.

    PubMed

    Barton, Pipi; Wilson, Denise

    2008-07-01

    Maori are often confronted with nursing practices and services that are at odds with their traditionally wholistic and spiritually based worldview. Keeping Maori clients the central focus of nursing practice can be challenging for nurses but is one way they can increase their efficacy when working with Maori. However, in the nursing literature there is an absence of models to guide Maori centred nursing practice, that is, models constructed within a Maori cultural context. Te Kapunga Putohe (the restless hands) is a Maori centred nursing practice model that uses the hands to illustrate how Maori knowledge and the knowledge of nurses can be incorporated into the health experiences of Maori clients. This paper explains how nurses who possess knowledge of Te Ao Maori can use Te Kapunga Putohe (the restless hands) to work with Maori in a culturally appropriate and acceptable way to improve health outcomes.

  18. Effect of Vaporub on the restlessness of children with acute bronchitis.

    PubMed

    Berger, H; Madreiter, H; Jarosch, E

    1978-01-01

    In this study pneumographs of children with acute bronchitis treated with Vicks Vaporub or Petrolatum were used. Movement artifacts were used as a measure of the so-called "restlessness" of the children. The experimental schedule consisted of a 10-minute phase of recording before a 3-minute treatment with Vaporub or Petrolatum, followed by a 70-minute observation period, during which time pneumograms were also recorded. Thirty-four Vaporub-treated children showed an increase in periods without movement artifacts of up to 213.8%, the Petrolatum controls, twenty-six children, up to 62.4% as compared to the corresponding pre-treatment values. It is concluded that Vaporub is effective in decreasing restlessness in children suffering from acute bronchitis. This effect is quite marked and cannot be due solely to psychological effects of the rub therapy, or to effects of petrolatum without aromatics.

  19. 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.

  20. 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. PMID:26812497

  1. Transcriptional quiescence of paternal mtDNA in cyprinid fish embryos.

    PubMed

    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

  2. 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.

  3. 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

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

    PubMed

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

    2015-08-01

    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

  5. 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

  6. Short communication: measures of weight distribution and frequency of steps as indicators of restless behavior.

    PubMed

    Chapinal, N; de Passillé, A M; Rushen, J; Tucker, C B

    2011-02-01

    Restless behavior, as measured by the steps taken or weight shifting between legs, may be a useful tool to assess the comfort of dairy cattle. These behaviors increase when cows stand on uncomfortable surfaces or are lame. The objective of this study was to compare 2 measures of restless behavior, stepping behavior and changes in weight distribution, on 2 standing surfaces: concrete and rubber. Twelve cows stood on a weighing platform with 1 scale/hoof for 1h. The platform was covered with either concrete or rubber, presented in a crossover design. Restlessness, as measured by both the frequency of steps and weight shifting (measured as the standard deviation of weight applied over time to the legs), increased over 1h of forced standing on either concrete or rubber. A positive relationship was found between the frequency of steps and the standard deviation of weight over 1h for both treatments and pairs of legs (r ≥ 0.66). No differences existed in the standard deviation of weight applied to the front (27.6 ± 1.6 kg) or rear legs (33.5 ± 1.4 kg) or the frequency of steps (10.2 ± 1.6 and 20.8 ± 3.2 steps/10 min for the front and rear pair, respectively) between rubber and concrete. Measures of restlessness are promising tools for assessing specific types of discomfort, such as those associated with lameness, but additional tools are needed to assess comfort of non-concrete standing surfaces.

  7. 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

  8. Epidemiology of a thermonuclear bomb-burst over Nashville, Tennessee: a theoretic study.

    PubMed

    Quinn, R W

    1983-07-01

    A thermonuclear bomb explosion over any city in the world would have a devastating effect on the population and environment. For those who survive, with or without injuries, life would become primitive with little or no uncontaminated food or water, and with inadequate housing, fuel, and medical care, resulting in a breakdown of family and interpersonal relationships. This theoretic study of the potential outcome of a thermonuclear bomb-burst over Nashville, Tennessee, discusses epidemiologically the wide range of medical and psychologic effects from the direct trauma of blast and fire, widespread epidemics of otherwise controlled disease, long-term chronic illness, genetic damage, and catastrophic environmental havoc.

  9. 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.

  10. 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.

  11. 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.

  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. 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.

  14. X-ray spectral evolution of X-ray binaries from outburst to quiescence

    NASA Astrophysics Data System (ADS)

    Degenaar, Nathalie

    2016-07-01

    In transient X-ray binaries a black hole or a neutron star accretes matter from a companion star at a rate that can vary by ~8 orders of magnitude. These large changes in the mass-accretion rate are associated with large changes in the accretion flow morphology and related outflows. I will discuss how the X-ray spectra of X-ray binaries evolve when transitioning from outburst to quiescence, how this may reflect changes in the accretion morphology, and what role the nature of the compact primary (i.e., neutron star versus black hole) plays in all this.

  15. Hot Spot in Eclipsing Dwarf Nova IY Ursae Majoris during Quiescence and Normal Outburst

    NASA Astrophysics Data System (ADS)

    Bąkowska, K.; Olech, A.

    2015-12-01

    We present the analysis of hot spot brightness in light curves of the eclipsing dwarf nova IY UMa during its normal outburst in March 2013 and in quiescence in April 2012 and in October 2015. Examination of four reconstructed light curves of the hot spot eclipses showed directly that the brightness of the hot spot changed significantly only during the outburst. The brightness of the hot spot, before and after the outburst, was on the same level. Thus, based on the behavior of the hot spot, IY UMa during its normal outburst follows the disk-instability model.

  16. [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. PMID:9203740

  17. [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.

  18. Lifestyle Factors and Risk of Restless Legs Syndrome: Prospective Cohort Study

    PubMed Central

    Batool-Anwar, Salma; Li, Yanping; De Vito, Katerina; Malhotra, Atul; Winkelman, John; Gao, Xiang

    2016-01-01

    Study Objectives: To examine the association between modifiable lifestyle factors, and the risk of developing restless legs syndrome (RLS). Methods: This is a Prospective Cohort study of population including 12,812 men participating in Health Professionals Follow-up Study and 42,728 women participating in the Nurses' Health study II. The participants were free of RLS at baseline (2002 for the HPFS and 2005 for the NHS II) and free of diabetes and arthritis through follow-up. RLS was assessed via a set of questions recommended by International Restless Legs Syndrome Study group. The Information was collected on height, weight, level of physical activity, dietary intake, and smoking status via questionnaires. Results: During 4–6 years of follow-up, we identified 1,538 incident RLS cases. Participants with normal weight, and who were physically active, non-smoker, and had some alcohol consumption had a lower risk of developing RLS. When we combined the effects of these four factors together, we observed a dose response relationship between the increased number of healthy lifestyle factors and a low risk of RLS: after adjusting for potential confounders the pooled odds ratio was 0.67 (95% CI: 0.47–0.97) for 4 vs.0 healthy factors (p trend < 0.001). In contrast, we did not observe significant associations between caffeine consumption or diet quality as assessed by the Alternate Healthy Eating Index, and altered RLS risk in men and women. Conclusions: Several modifiable lifestyle factors may play an important role in RLS risk. Citation: Batool-Anwar S, Li Y, De Vito K, Malhotra A, Winkelman J, Gao X. Lifestyle factors and risk of restless legs syndrome: prospective cohort study. J Clin Sleep Med 2016;12(2):187–194. PMID:26446243

  19. Restless Legs Syndrome/Willis-Ekbom Disease and Growing Pains in Children and Adolescents.

    PubMed

    Simakajornboon, Narong; Dye, Thomas J; Walters, Arthur S

    2015-09-01

    Recent studies have shown that restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are common in pediatric population. The diagnostic criteria for Pediatric RLS have recently been updated to simplify and integrate with newly revised adult RLS criteria. Management of RLS and PLMD involves pharmacologic and nonpharmacologic interventions. Children with low iron storage are likely to benefit from iron therapy. Although, there is limited information on pharmacologic therapy, there are emerging literatures showing the effectiveness of dopaminergic medications in the management of RLS and PLMD in children. This article covers clinical evaluation of RLS and PLMD in children and the relationship with growing pains. PMID:26329441

  20. Restless Legs Syndrome/Willis-Ekbom Disease Morbidity: Burden, Quality of Life, Cardiovascular Aspects, and Sleep.

    PubMed

    Stevens, Mary Suzanne

    2015-09-01

    Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) has a significant negative effect on quality of life. The decreased quality of life is similar to that of other chronic diseases, such as diabetes type 2, depression, and osteoarthritis. RLS/WED disrupts sleep length, sleep quality, and daytime alertness. Sleep disruption can contribute to depression. RLS/WED has been associated with cardiovascular disease and high blood pressure, possibly because of increased sympathetic tone caused by periodic limb movements of sleep. RLS/WED is underdiagnosed, leading to chronic sleep disruption and daytime consequences. Patients with RLS/WED have decreased productivity at work, which potentially has far-reaching economic consequences.

  1. Management of Restless Legs Syndrome/Willis-Ekbom Disease in Hospitalized and Perioperative Patients.

    PubMed

    Goldstein, Cathy

    2015-09-01

    Restless legs syndrome (RLS) is a sensorimotor disorder that can cause significant discomfort, impaired quality of life, poor mood, and disturbed sleep. Because the disorder is chronic and associated with multiple comorbidities, RLS can be seen in an inpatient or perioperative setting. Certain characteristics of the hospitalized or surgical context can exacerbate or unmask RLS. Importantly, RLS and the associated discomfort and insomnia can prolong hospital stay and negatively impact outcomes. RLS medications should be continued during the hospital admission when possible. Avoidance of excessive phlebotomy and medications known to trigger RLS is helpful. Patients should increase activity when acceptable.

  2. PTPRD (protein tyrosine phosphatase receptor type delta) is associated with restless legs syndrome.

    PubMed

    Schormair, Barbara; Kemlink, David; Roeske, Darina; Eckstein, Gertrud; Xiong, Lan; Lichtner, Peter; Ripke, Stephan; Trenkwalder, Claudia; Zimprich, Alexander; Stiasny-Kolster, Karin; Oertel, Wolfgang; Bachmann, Cornelius G; Paulus, Walter; Högl, Birgit; Frauscher, Birgit; Gschliesser, Viola; Poewe, Werner; Peglau, Ines; Vodicka, Pavel; Vávrová, Jana; Sonka, Karel; Nevsimalova, Sona; Montplaisir, Jacques; Turecki, Gustavo; Rouleau, Guy; Gieger, Christian; Illig, Thomas; Wichmann, H-Erich; Holsboer, Florian; Müller-Myhsok, Bertram; Meitinger, Thomas; Winkelmann, Juliane

    2008-08-01

    We identified association of restless legs syndrome (RLS) with PTPRD at 9p23-24 in 2,458 affected individuals and 4,749 controls from Germany, Austria, Czechia and Canada. Two independent SNPs in the 5' UTR of splice variants expressed predominantly in the central nervous system showed highly significant P values (rs4626664, P(nominal/lambda corrected) = 5.91 x 10(-10), odds ratio (OR) = 1.44; rs1975197, P(nominal/lambda corrected) = 5.81 x 10(-9), OR = 1.31). This work identifies PTPRD as the fourth genome-wide significant locus for RLS.

  3. Differential Diagnoses of Restless Legs Syndrome/Willis-Ekbom Disease: Mimics and Comorbidities.

    PubMed

    Chokroverty, Sudhansu

    2015-09-01

    Restless legs syndrome (RLS) mimics cannot always be differentiated from RLS/Willis-Ekbom disease (WED) based on 4 essential criteria; hence, a fifth criterion has recently been established. RLS comorbidities may provide us important clues for understanding the neurobiology of RLS/WED. Iron-dopamine connection, hypoxia pathway activation, and dopamine-opioid interaction are important pathophysiological mechanisms in RLS; this knowledge is derived from our understanding of RLS associations with a variety of medical, neurologic, and other conditions. Clinicians must formulate an RLS differential diagnosis based on history and physical examination, but laboratory tests may sometimes be needed to arrive at a correct diagnosis. PMID:26329435

  4. Toward a Definition of Quality Care for Patients with Restless Legs Syndrome.

    PubMed

    Trotti, Lynn Marie

    2015-09-01

    Health care systems and payers are placing increasing emphasis on the measurement and improvement of quality. The process of quality improvement is complex but can be supported by professional organizations such as the American Academy of Sleep Medicine (AASM). In 2013, the AASM commissioned a series of restless legs syndrome (RLS)-specific quality measures, consisting of process and outcome measures. This article provides an overview of the measure development process and discusses the individual RLS quality measures. These measures were designed to support the goals of improved diagnostic accuracy, decreased symptom severity, and reduced treatment complications. PMID:26329439

  5. Medical devices for restless legs syndrome – clinical utility of the Relaxis pad

    PubMed Central

    Mitchell, Ulrike H

    2015-01-01

    Restless Legs Syndrome or Willis–Ekbom Disease, a neurosensory disorder, can be treated with pharmaceuticals or conservatively. This review focuses on conservative treatments, more specifically on treatments with medical devices. Two modes of action, enhancement of circulation and counter stimulation, are introduced. Medical devices that use enhancement of circulation as their mechanism of action are whole body vibration, pneumatic compression, and near-infrared light. Medical devices that use counter stimulation include transcutaneous electrical nerve stimulation and the vibration Relaxis pad. The clinical utility of the Relaxis pad and its place in therapy is proposed. PMID:26664128

  6. Plans for living on a restless planet sets NASA's solid Earth agenda

    NASA Technical Reports Server (NTRS)

    Solomon, S. C.; Baker, V. R.; Bloxham, J.; Booth, J.; Donnellan, A.; Elachi, C.; Evans, D.; Rignot, E.; Burbank, D.; Chao, B. F.; Chave, A.; Gillespie, A.; Herring, T.; Jeanloz, R.; LaBrecque, J.; Minster, B.; Pitman, W. C., III; Simons, M.; Turcotte, D. L.; Zoback, M. L.

    2003-01-01

    What are the most important challenges facing solid Earth science today and over the next two decades? And what is the best approach for NASA, in partnership with other agencies, to address these challenges? A new report, living on a restless planet, provides a blueprint for answering these questions. The top priority for a new spacecraft mission in the area of solid earth science over the next 5 years, according to this report, is a satellite dedicated to interferometric synthetic aperture radar(inSAR).

  7. Runx1 and p21 synergistically limit the extent of hair follicle stem cell quiescence in vivo.

    PubMed

    Lee, Jayhun; Hoi, Charlene S L; Lilja, Karin C; White, Brian S; Lee, Song Eun; Shalloway, David; Tumbar, Tudorita

    2013-03-19

    Mechanisms of tissue stem cell (SC) quiescence control are important for normal homeostasis and for preventing cancer. Cyclin-dependent kinase inhibitors (CDKis) are known inhibitors of cell cycle progression. We document CDKis expression in vivo during hair follicle stem cell (HFSC) homeostasis and find p21 (cyclin-dependent kinase inhibitor 1a, Cdkn1a), p57, and p15 up-regulated at quiescence onset. p21 appears important for HFSC timely onset of quiescence. Conversely, we find that Runx1 (runt related transcription factor 1), which is known for promoting HFSC proliferation, represses p21, p27, p57, and p15 transcription in HFSC in vivo. Intriguingly, in cell culture, tumors, and normal homeostasis, Runx1 and p21 interplay modulates proliferation in opposing directions under the different conditions. Unexpectedly, Runx1 and p21 synergistically limit the extent of HFSC quiescence in vivo, which antagonizes the role of p21 as a cell cycle inhibitor. Importantly, we find in cultured keratinocytes that Runx1 and p21 bind to the p15 promoter and synergistically repress p15 mRNA transcription, thereby restraining cell cycle arrest. This documents a surprising ability of a CDKi (p21) to act as a direct transcriptional repressor of another CDKi (p15). We unveil a robust in vivo mechanism that enforces quiescence of HFSCs, and a context-dependent role of a CDKi (p21) to limit quiescence of SCs, potentially by directly down-regulating mRNA levels of (an)other CDKi(s).

  8. 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

  9. 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.

  10. Post-transcriptional regulation of satellite cell quiescence by TTP-mediated mRNA decay.

    PubMed

    Hausburg, Melissa A; Doles, Jason D; Clement, Sandra L; Cadwallader, Adam B; Hall, Monica N; Blackshear, Perry J; Lykke-Andersen, Jens; Olwin, Bradley B

    2015-03-27

    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.

  11. 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. PMID:26334984

  12. Degassing during quiescence as a trigger of magma ascent and volcanic eruptions.

    PubMed

    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

  13. 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

  14. FUSE Observations of the Dwarf Novae UU Aql, BV Cen, and CH UMa in Quiescence

    NASA Astrophysics Data System (ADS)

    Sion, Edward M.; Godon, Patrick; Cheng, Fuhua; Szkody, Paula

    2007-08-01

    We report on FUSE spectra of three U Gem-type, long-period dwarf novae, UU Aql, BV Cen, and CH UMa, taken during their quiescence intervals. We discuss the line identifications in their spectra and attempt to characterize the source(s) of their FUV flux distribution. Archival IUE spectra of CH UMa and BV Cen in quiescence were identified as having a matching flux level with the FUSE spectra, and these were combined with each FUSE spectrum to broaden the wavelength coverage and further constrain model fits. Multicomponent synthetic spectral fits from our model grids, consisting of single-temperature white dwarfs, two-temperature white dwarfs, accretion disks, and white dwarfs plus accretion disks, were applied to the FUSE spectra alone and to the combined FUSE + IUE spectra. We present the results of our model analyses and their implications. Based on observations made with the NASA-CNES-CSA Far-Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS5-32985.

  15. 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.

  16. The transcription factor E74-like factor controls quiescence of endothelial cells and their resistance to myeloablative treatments in bone marrow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Restless legs syndrome in children: a review and update on pharmacological options.

    PubMed

    Frenette, Eric

    2011-01-01

    Restless legs syndrome (RLS), formally identified and described by Ekbom in the 1940s, is a common clinical disorder, characterized by an overwhelming urge to move the legs, often accompanied by uncomfortable and unpleasant sensations. This impulse can also be present in the upper limbs or other parts of the body. Well recognized in the adult population, the symptoms associated with this condition have commonly been reported to originate in childhood. However, identifying prospectively children suffering from RLS is still a challenging issue. Iron deficiency has been recognized as a feature frequently associated with RLS. Some authors also make a connection with the deficiency, RLS and other common problems encountered in children, such as attention deficit disorder with hyperactivity (ADHD). Linkage to different chromosomal loci has been achieved in recent genetic studies of large kindred, as well as identification of specific genes. Therapeutic considerations in children range from providing sound sleep hygiene to intervening pharmacologically. In that regard, use of iron supplements, dopaminergic stimulation, anticonvulsants, opiates, and benzodiazepines will be assessed along with newer options, such as rotigotine and gabapentin enacarbil. Considerations specific to childhood do apply, as no pharmacological therapy for restless legs syndrome have been approved by the Federal Drug Administration (FDA) in individuals of the pediatric age group.

  18. Diagnostic indicators of restless legs syndrome in primary care consultations: the DESYR study.

    PubMed

    Crochard, Anne; El Hasnaoui, Abdelkader; Pouchain, Denis; Huas, Dominique; Arnulf, Isabelle; Krieger, Jean; Lainey, Eric; Le Jeunne, Philippe; Leger, Damien; Schuck, Stéphane; Texier, Nathalie; Tison, François; Montplaisir, Jacques

    2007-04-30

    The objective of this study is to determine whether spontaneous complaints about sleep or the legs could be used as potential indicators of restless legs syndrome (RLS) in primary care. A total of 351 general practitioners participated in the study. In a first historical patient identification phase, all patients with spontaneous complaints of sleep or leg symptoms over the previous year were identified. A control group without such complaints was identified. In a second prospective data collection phase, those who consulted a participating physician were interviewed to assess consensus diagnostic criteria of RLS. Severity was assessed with the International Restless Legs Syndrome Study Group severity rating scale. Of 1,405,823 patients consulting during the historical phase, a leg complaint was reported in 61,685 and a sleep complaint in 40,568. A total of 1,432 consulted during the prospective phase. A diagnosis of RLS was assigned to 42.6% of patients with leg complaints, 35.5% of those with sleep complaints, 54.9% of those with both complaints, and 12.9% of those with no complaints. Median RLS severity scores were 18.8 to 20.4. A total of 63.7% of patients were prescribed a venotonic, 43.7% a hypnotic, and 41.5% an anxiolytic. Complaints of sleep or leg symptoms are frequently associated with a diagnosis of RLS, and their presence should alert the physician to the possibility of a differential diagnosis of RLS. PMID:17230475

  19. Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

    PubMed

    Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

    2015-08-01

    While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed. PMID:25348826

  20. Restless legs syndrome in children: a review and update on pharmacological options.

    PubMed

    Frenette, Eric

    2011-01-01

    Restless legs syndrome (RLS), formally identified and described by Ekbom in the 1940s, is a common clinical disorder, characterized by an overwhelming urge to move the legs, often accompanied by uncomfortable and unpleasant sensations. This impulse can also be present in the upper limbs or other parts of the body. Well recognized in the adult population, the symptoms associated with this condition have commonly been reported to originate in childhood. However, identifying prospectively children suffering from RLS is still a challenging issue. Iron deficiency has been recognized as a feature frequently associated with RLS. Some authors also make a connection with the deficiency, RLS and other common problems encountered in children, such as attention deficit disorder with hyperactivity (ADHD). Linkage to different chromosomal loci has been achieved in recent genetic studies of large kindred, as well as identification of specific genes. Therapeutic considerations in children range from providing sound sleep hygiene to intervening pharmacologically. In that regard, use of iron supplements, dopaminergic stimulation, anticonvulsants, opiates, and benzodiazepines will be assessed along with newer options, such as rotigotine and gabapentin enacarbil. Considerations specific to childhood do apply, as no pharmacological therapy for restless legs syndrome have been approved by the Federal Drug Administration (FDA) in individuals of the pediatric age group. PMID:21476956

  1. Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

    PubMed

    Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

    2015-08-01

    While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed.

  2. Seismic quiescence precursors to two M7 earthquakes on Sakhalin Island, measured by two methods

    NASA Astrophysics Data System (ADS)

    Wyss, Max; Sobolev, Gennady; Clippard, James D.

    2004-08-01

    Two large earthquakes occurred during the last decade on Sakhalin Island, the M w 7.6 Neftegorskoe earthquake of 27 May 1995 and the M w 6.8 Uglegorskoe earthquake of 4 August 2000, in the north and south of the island, respectively. Only about five seismograph stations record earthquakes along the 1000 km, mostly strike-slip plate boundary that transects the island from north to south. In spite of that, it was possible to investigate seismicity patterns of the last two to three decades quantitatively. We found that in, and surrounding, their source volumes, both of these main shocks were preceded by periods of pronounced seismic quiescence, which lasted 2.5 ± 0.5 years. The distances to which the production of earthquakes was reduced reached several hundred kilometers. The probability that these periods of anomalously low seismicity occurred by chance is estimated to be about 1% to 2%. These conclusions were reached independently by the application of two methods, which are based on different approaches. The RTL-algorithm measures the level of seismic activity in moving time windows by counting the number of earthquakes, weighted by their size, and inversely weighted by their distance, in time and space from the point of observation. The Z-mapping approach measures the difference of the seismicity rate, within moving time windows, to the background rate by the standard deviate Z. This generates an array of comparisons that cover all of the available time and space, and that can be searched for all anomalous departures from the normal seismicity rate. The RTL-analysis was based on the original catalog with K-classes measuring the earthquake sizes; the Z-mapping was based on the catalog with Ktransformed into magnitudes. The RTL-analysis started with data from 1980, the Z-mapping technique used the data from 1974 on. In both methods, cylindrical volumes, centered at the respective epicenters, were sampled. The Z-mapping technique additionally investigated the

  3. 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

  4. 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

  5. On the language and physiology of dormancy and quiescence in plants.

    PubMed

    Considine, Michael J; Considine, John A

    2016-05-01

    The language of dormancy is rich and poetic, as researchers spanning disciplines and decades have attempted to understand the spell that entranced 'Sleeping Beauty', and how she was gently awoken. The misleading use of 'dormancy', applied to annual axillary buds, for example, has confounded progress. Language is increasingly important as genetic and genomic approaches become more accessible to species of agricultural and ecological importance. Here we examine how terminology has been applied to different eco-physiological states in plants, and with pertinent reference to quiescent states described in other domains of life, in order to place plant quiescence and dormancy in a more complete context than previously described. The physiological consensus defines latency or quiescence as opportunistic avoidance states, where growth resumes in favourable conditions. In contrast, the dormant state in higher plants is entrained in the life history of the organism. Competence to resume growth requires quantitative and specific conditioning. This definition applies only to the embryo of seeds and specialized meristems in higher plants; however, mechanistic control of dormancy extends to mobile signals from peripheral tissues and organs, such as the endosperm of seed or subtending leaf of buds. The distinction between dormancy, quiescence, and stress-hardiness remains poorly delineated, most particularly in buds of winter perennials, which comprise multiple meristems of differing organogenic states. Studies in seeds have shown that dormancy is not a monogenic trait, and limited study has thus far failed to canalize dormancy as seen in seeds and buds. We argue that a common language, based on physiology, is central to enable further dissection of the quiescent and dormant states in plants. We direct the topic largely to woody species showing a single cycle of growth and reproduction per year, as these bear the majority of global timber, fruit, and nut production, as well being

  6. Thomas de Quincey and his restless legs symptoms as depicted in "Confessions of an English Opium-Eater".

    PubMed

    Miranda, Marcelo; Williams, Anne-Marie; Garcia-Borreguero, Diego

    2010-10-15

    Thomas de Quincey, a British writer of 19th century, suffered insomnia from the age of 17 years. In his famous "Confessions of an English-Opium Eater" (1822), he described a symptomatology that could concord with restless legs syndrome long before he became addicted to opium. In this report, we analyze his clinical description and the circumstances leading to his opium addiction.

  7. Migratory Restlessness and the Role of Androgen for Increasing Behavioral Drive in the Spawning Migration of the Japanese eel

    PubMed Central

    Sudo, Ryusuke; Tsukamoto, Katsumi

    2015-01-01

    Migratory restlessness refers to a type of locomotor activity observed just before the onset of a migration. This behavior is primarily known in birds, where it is considered to be an indicator of the urge for migration. In contrast, little is known about migratory restlessness in fishes. To confirm migratory restlessness in a fish, we measured the locomotor activity of the Japanese eel, Anguilla japonica during its migration season. Migratory-phase silver eels showed higher locomotor activity in aquaria than yellow eels at the non-migratiory growth-phase. Silver eels stayed outside of their shelters for longer durations in dark periods than yellow eels and were active even in light periods when yellow eels were inactive in the shelters. Silver eels had higher levels of the androgen hormone 11-ketotestosterone at the end of experiment than yellow eels. Administration of 11-ketotesosterone to yellow eels induced higher levels of locomotor activity than that observed in non-treated controls. These findings suggest that anguillid eels exhibit migratory restlessness just before their spawning migration and that 11-ketotestosterone may be involved in the onset of this behavior. PMID:26617079

  8. Migratory Restlessness and the Role of Androgen for Increasing Behavioral Drive in the Spawning Migration of the Japanese eel.

    PubMed

    Sudo, Ryusuke; Tsukamoto, Katsumi

    2015-11-30

    Migratory restlessness refers to a type of locomotor activity observed just before the onset of a migration. This behavior is primarily known in birds, where it is considered to be an indicator of the urge for migration. In contrast, little is known about migratory restlessness in fishes. To confirm migratory restlessness in a fish, we measured the locomotor activity of the Japanese eel, Anguilla japonica during its migration season. Migratory-phase silver eels showed higher locomotor activity in aquaria than yellow eels at the non-migratiory growth-phase. Silver eels stayed outside of their shelters for longer durations in dark periods than yellow eels and were active even in light periods when yellow eels were inactive in the shelters. Silver eels had higher levels of the androgen hormone 11-ketotestosterone at the end of experiment than yellow eels. Administration of 11-ketotesosterone to yellow eels induced higher levels of locomotor activity than that observed in non-treated controls. These findings suggest that anguillid eels exhibit migratory restlessness just before their spawning migration and that 11-ketotestosterone may be involved in the onset of this behavior.

  9. A combination of valerian and lemon balm is effective in the treatment of restlessness and dyssomnia in children.

    PubMed

    Müller, S F; Klement, S

    2006-06-01

    Efficacy and tolerability of a combined valerian/lemon balm preparation were investigated in an open, multicentre study in children less than 12 years suffering from restlessness and nervous dyskoimesis. Patients were dosed individually by the investigators. In total, 918 children were evaluated for therapeutic efficacy and tolerability. A distinct and convincing reduction in severity was found for all symptoms in the investigators' and parents' ratings. The core symptoms dyssomnia and restlessness were reduced from "moderate/severe" to "mild" or "absent" in most of the patients. In total, 80.9% of the patients who suffered from dyssomnia experienced an improvement for this symptom and 70.4% of the patients with restlessness improved clearly. For the other listed symptoms the total improvement was 37.8% on average. Both, parents and investigators assessed efficacy as to be "very good" or "good" (60.5% and 67.7%, respectively). The tolerability of Euvegal forte was considered as "good" (in 96.7% of the patients it was judged to be "very good" or "good"). No study medication-related adverse events occurred. In conclusion, Euvegal forte was effective in the treatment of younger children with restlessness and dyssomnia and it was very well tolerated.

  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. PMID:26076315

  11. The DREAM complex mediates GIST cell quiescence and is a novel therapeutic target to enhance imatinib-induced apoptosis.

    PubMed

    Boichuk, Sergei; Parry, Joshua A; Makielski, Kathleen R; Litovchick, Larisa; Baron, Julianne L; Zewe, James P; Wozniak, Agnieszka; Mehalek, Keith R; Korzeniewski, Nina; Seneviratne, Danushka S; Schöffski, Patrick; Debiec-Rychter, Maria; DeCaprio, James A; Duensing, Anette

    2013-08-15

    Gastrointestinal stromal tumors (GIST) can be successfully treated with imatinib mesylate (Gleevec); however, complete remissions are rare and patients frequently achieve disease stabilization in the presence of residual tumor masses. The clinical observation that discontinuation of treatment can lead to tumor progression suggests that residual tumor cells are, in fact, quiescent and, therefore, able to re-enter the cell-division cycle. In line with this notion, we have previously shown that imatinib induces GIST cell quiescence in vitro through the APC(CDH1)-SKP2-p27(Kip1) signaling axis. Here, we provide evidence that imatinib induces GIST cell quiescence in vivo and that this process also involves the DREAM complex, a multisubunit complex that has recently been identified as an additional key regulator of quiescence. Importantly, inhibition of DREAM complex formation by depletion of the DREAM regulatory kinase DYRK1A or its target LIN52 was found to enhance imatinib-induced cell death. Our results show that imatinib induces apoptosis in a fraction of GIST cells while, at the same time, a subset of cells undergoes quiescence involving the DREAM complex. Inhibition of this process enhances imatinib-induced apoptosis, which opens the opportunity for future therapeutic interventions to target the DREAM complex for more efficient imatinib responses. PMID:23786773

  12. FRPR-4 Is a G-Protein Coupled Neuropeptide Receptor That Regulates Behavioral Quiescence and Posture in Caenorhabditis elegans.

    PubMed

    Nelson, Matthew D; Janssen, Tom; 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. Uropathogenic Escherichia coli Metabolite-Dependent Quiescence and Persistence May Explain Antibiotic Tolerance during Urinary Tract Infection.

    PubMed

    Leatham-Jensen, Mary P; Mokszycki, Matthew E; Rowley, David C; Deering, Robert; Camberg, Jodi L; Sokurenko, Evgeni V; Tchesnokova, Veronika L; Frimodt-Møller, Jakob; Krogfelt, Karen A; Leth Nielsen, Karen; Frimodt-Møller, Niels; Sun, Gongqin; Cohen, Paul S

    2016-01-01

    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 ≤10(6) 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 for recurrent

  18. 1D-Simulation of Thermonuclear Target Compression and Burning for Laser Facility NIF and LMJ

    NASA Astrophysics Data System (ADS)

    Valiev, R. Zh.; Chizhkov, M. N.; Karlyhanov, N. G.; Lusganova, O. V.; Lykov, V. A.; Netsvetayev, D. S.; Timakova, M. S.

    2006-08-01

    The high-power laser facilities NIF and LMJ with the pulse energy as high as 2 MJ are being created in the USA and France. The basic cryogenic indirect-drive targets for thermonuclear ignition on these facilities are a spherical shell from polystyrene doped with oxygen and bromine. (CH+5%O+0,25%Br), whose inner surface is covered with DT-ice layer. The central region of targets is filled with DT-gas. The targets for NIF and LMJ have different external radii (1,11 and 1,215 mm, correspondingly), masses of DT-fuel (210 и 310 μg), X-ray radiation temperature dependences in time. The thermonuclear yield from the NIF target calculated with LASNEX code is 15 MJ, the yield from the LMJ target calculated with FCI1 code is 25.4 MJ. In RFNC-VNIITF calculations of compression and burning of basic NIF and LMJ targets were performed by using of the 1D ERA code in the spectral diffusion approximation for radiation transfer. We used tabulated opacity calculated by the mean ion model. Thermonuclear yield calculated with ERA code is about 18 MJ for the NIF target and nearly 23 MJ for the LMJ target. Calculated yields are in good agreement with published results. Performed calculations justified the possibility to simulate ICF targets in RFNC-VNIITF. In paper are also presented analysis results of target sensitivity to opacity and X-ray temperature variations.

  19. 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.

  20. Experimental investigation of the 30S(α, p) thermonuclear reaction in x-ray bursts

    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.

    2016-02-01

    We performed the first measurement of 30S+α resonant elastic scattering to experimentally examine the 30S(α, p) stellar reaction rate in type I x-ray bursts. These bursts are the most frequent thermonuclear explosions in the galaxy, resulting from thermonuclear runaway on the surface of accreting neutron star binaries. The 30S(α, p) reaction plays a critical role in burst models, yet very little is known about the compound nucleus 34Ar at these energies nor the reaction rate itself. We performed a measurement of alpha elastic scattering with a radioactive beam of 30S to experimentally probe the entrance channel. Utilizing a gaseous active target system and silicon detector array, we extracted the excitation function from 1.8 to 5.5 MeV near 160° in the center-of-mass frame. The experimental data were analyzed with an R-Matrix calculation, and we discovered several new resonances and extracted their quantum properties (resonance energy, width, spin, and parity). Finally, we calculated the narrow resonant thermonuclear reaction rate of 30S(α, p) for these new resonances.

  1. RAT J1953+1859: a dwarf nova discovered through high amplitude QPOs in quiescence

    NASA Astrophysics Data System (ADS)

    Ramsay, Gavin; Hakala, Pasi; Barclay, Thomas; Wheatley, Peter; Marshall, George; Lehto, Harry; Napiwotzki, Ralf; Nelemans, Gijs; Potter, Stephen; Todd, Ian

    2009-09-01

    We report the discovery of an accreting binary, RAT J1953+1859, made during the RApid Temporal Survey (RATS) on the Isaac Newton Telescope. It showed high amplitude (0.3 mag) quasi-periodic oscillations on a time-scale of ~20 min. Further observations made using the Nordic Optical Telescope showed it to be ~4 mag brighter than in the discovery images. These photometric observations, together with radial velocity data taken using the William Herschel Telescope, point to an orbital period of ~90 min. These data suggest that RAT J1953+1859 is a dwarf novae of the SU UMa type. What makes RAT J1953+1859 unusual is that it is the first such system to be discovered as a result of high amplitude QPOs during quiescence. This suggests that high-cadence wide-field surveys could be another means to discover cataclysmic variables as a result of their short period variability.

  2. Quiescence does not affect p53 and stress response by irradiation in human lung fibroblasts

    SciTech Connect

    Dai, Jiawen; Itahana, Koji; Baskar, Rajamanickam

    2015-02-27

    Cells in many organs exist in both proliferating and quiescent states. Proliferating cells are more radio-sensitive, DNA damage pathways including p53 pathway are activated to undergo either G{sub 1}/S or G{sub 2}/M arrest to avoid entering S and M phase with DNA damage. On the other hand, quiescent cells are already arrested in G{sub 0}, therefore there may be fundamental difference of irradiation response between proliferating and quiescent cells, and this difference may affect their radiosensitivity. To understand these differences, proliferating and quiescent human normal lung fibroblasts were exposed to 0.10–1 Gy of γ-radiation. The response of key proteins involved in the cell cycle, cell death, and metabolism as well as histone H2AX phosphorylation were examined. Interestingly, p53 and p53 phosphorylation (Ser-15), as well as the cyclin-dependent kinase inhibitors p21 and p27, were induced similarly in both proliferating and quiescent cells after irradiation. Furthermore, the p53 protein half-life, and expression of cyclin A, cyclin E, proliferating cell nuclear antigen (PCNA), Bax, or cytochrome c expression as well as histone H2AX phosphorylation were comparable after irradiation in both phases of cells. The effect of radioprotection by a glycogen synthase kinase 3β inhibitor on p53 pathway was also similar between proliferating and quiescent cells. Our results showed that quiescence does not affect irradiation response of key proteins involved in stress and DNA damage at least in normal fibroblasts, providing a better understanding of the radiation response in quiescent cells, which is crucial for tissue repair and regeneration. - Highlights: • p53 response by irradiation was similar between proliferating and quiescent cells. • Quiescent cells showed similar profiles of cell cycle proteins after irradiation. • Radioprotection of GSK-3β inhibitor caused similar effects between these cells. • Quiescence did not affect p53 response despite its

  3. The black hole binary V4641 Sagitarii: Activity in quiescence and improved mass determinations

    SciTech Connect

    MacDonald, Rachel K. D.; Bailyn, Charles D.; Buxton, Michelle; Cantrell, Andrew G.; Chatterjee, Ritaban; Kennedy-Shaffer, Ross; Orosz, Jerome A.; Markwardt, Craig B.; Swank, Jean H.

    2014-03-20

    We examine ∼10 yr of photometric data and find that the black hole X-ray binary V4641 Sgr has two optical states, passive and active, during X-ray quiescence. The passive state is dominated by ellipsoidal variations and is stable in the shape and variability of the light curve. The active state is brighter and more variable. Emission during the active state varies over the course of the orbital period and is redder than the companion star. These optical/infrared states last for weeks or months. V4641 Sgr spends approximately 85% of X-ray quiescence in the passive state and 15% in the active. We analyze passive colors and spectroscopy of V4641 Sgr and show that they are consistent with a reddened B9III star (with E(B – V) = 0.37 ± 0.19) with little or no contribution from the accretion disk. We use X-ray observations with an updated ephemeris to place an upper limit on the duration of an X-ray eclipse of <8.°3 in phase (∼1.6 hr). High-resolution spectroscopy yields a greatly improved measurement of the rotational velocity of the companion star of V {sub rot}sin i = 100.9 ± 0.8 km s{sup –1}. We fit ellipsoidal models to the passive state data and find an inclination angle of i = 72.3 ± 4.°1, a mass ratio of Q = 2.2 ± 0.2, and component masses for the system of M {sub BH} = 6.4 ± 0.6 M {sub ☉} and M {sub 2} = 2.9 ± 0.4 M {sub ☉}. Using these values we calculate an updated distance to V4641 Sgr of 6.2 ± 0.7 kpc.

  4. Stable and unstable phases of elevated seismic activity at the persistently restless Telica Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Rodgers, Mel; Roman, Diana C.; Geirsson, Halldor; LaFemina, Peter; McNutt, Stephen R.; Muñoz, Angelica; Tenorio, Virginia

    2015-01-01

    Telica Volcano, Nicaragua, is a persistently restless volcano with daily seismicity rates that can vary by orders of magnitude without apparent connection to eruptive activity. Low-frequency (LF) events are dominant and peaks in seismicity rate show little correlation with eruptive episodes, presenting a challenge for seismic monitoring and eruption forecasting. A short period seismic station (TELN) has been operated on Telica's summit since 1993, and in 2010 the installation of a six-station broadband seismic and eleven-station continuous GPS network (the TESAND network) was completed to document in detail the seismic characteristics of a persistently restless volcano. Between our study period of November 2009 and May 2013, over 400,000 events were detected at the TESAND summit station (TBTN), with daily event rates ranging from 5 to 1400. We present spectral analyses and classifications of ~ 200,000 events recorded by the TESAND network between April 2010 and March 2013, and earthquake locations for a sub-set of events between July 2010 and February 2012. In 2011 Telica erupted in a series of phreatic vulcanian explosions. Six months before the 2011 eruption, we observe a sudden decrease in LF events concurrent with a swarm of high-frequency (HF) events, followed by a decline in overall event rates, which reached a minimum at the eruption onset. We observe repeated periods of high and low seismicity rates and suggest these changes in seismicity represent repeated transitions between open-system and closed-system degassing. We suggest that these short- and long-term transitions between open to closed-system degassing form part of a long-term pattern of stable vs. unstable phases at Telica. Stable phases are characterised by steady high-rate seismicity and represent stable open-system degassing, whereas unstable phases are characterised by highly variable seismicity rates and represent repeated transitions from open to closed-system degassing, where the system is

  5. The Rim15-Endosulfine-PP2ACdc55 Signalling Module Regulates Entry into Gametogenesis and Quiescence via Distinct Mechanisms in Budding Yeast

    PubMed Central

    Sarkar, Sourav; Dalgaard, Jacob Z.; Millar, Jonathan B. A.; Arumugam, Prakash

    2014-01-01

    Quiescence and gametogenesis represent two distinct survival strategies in response to nutrient starvation in budding yeast. Precisely how environmental signals are sensed by yeast cells to trigger quiescence and gametogenesis is not fully understood. A conserved signalling module consisting of Greatwall kinase, Endosulfine and Protein Phosphatase PP2ACdc55 proteins regulates entry into mitosis in Xenopus egg extracts and meiotic maturation in flies. We report here that an analogous signalling module consisting of the serine-threonine kinase Rim15, the Endosulfines Igo1 and Igo2 and the Protein Phosphatase PP2ACdc55, regulates entry into both quiescence and gametogenesis in budding yeast. PP2ACdc55 inhibits entry into gametogenesis and quiescence. Rim15 promotes entry into gametogenesis and quiescence by converting Igo1 into an inhibitor of PP2ACdc55 by phosphorylating at a conserved serine residue. Moreover, we show that the Rim15-Endosulfine-PP2ACdc55 pathway regulates entry into quiescence and gametogenesis by distinct mechanisms. In addition, we show that Igo1 and Igo2 are required for pre-meiotic autophagy but the lack of pre-meiotic autophagy is insufficient to explain the sporulation defect of igo1Δ igo2Δ cells. We propose that the Rim15-Endosulfine-PP2ACdc55 signalling module triggers entry into quiescence and gametogenesis by regulating dephosphorylation of distinct substrates. PMID:24968058

  6. Restless leg syndrome in hospitalized psychiatric patients in Lebanon: a pilot study

    PubMed Central

    Talih, Farid; Ajaltouni, Jean; Kobeissy, Firas

    2016-01-01

    Objectives To characterize and describe the prevalence of restless leg syndrome (RLS) in hospitalized psychiatric patients and to investigate the correlations between patient profile and RLS. Methods Demographic information, psychiatric diagnoses, psychotropic medication use, and history of substance use were collected from hospitalized psychiatric patients at the American University of Beirut Medical Center; Beirut, Lebanon. A validated questionnaire to evaluate RLS symptomatology was also administered to 126 participants who agreed to participate, as well as questionnaires for insomnia, depression, and anxiety symptoms. Statistical analysis was conducted to detect the prevalence of RLS among the participants and to examine correlations with RLS in a hospitalized psychiatric population. Results Out of the 126 participants who completed the survey, RLS was detected in 18% of the participants. Of interest, RLS was also found to be associated with higher depressive symptomatology, suicidal ideation, and working night shifts. PMID:27785035

  7. Restless Legs Syndrome, Sleep, and Quality of Life among Adolescents and Young Adults

    PubMed Central

    Silva, Graciela E.; Goodwin, James L.; Vana, Kimberly D.; Vasquez, Monica M.; Wilcox, Peter G.; Quan, Stuart F.

    2014-01-01

    Objective: Clinical reports in children implicate restless legs syndrome (RLS) with sleep and behavior problems. However, population-based studies on this association in adolescents and young adults are limited. Furthermore, few studies have evaluated the association between symptoms consistent with RLS and quality of life (QoL). Study Design: This cross-sectional study included 214 Caucasian and Hispanic adolescents and young adults aged 12-20 years. Symptoms consistent with RLS were based on four essential criteria and if the symptoms occurred ≥ 5 days/ month. Trouble falling asleep was present if reported “yes, still have the problem.” Quality of life (QoL) was assessed using the Pediatric QoL Inventory. Three summary QoL scores ranging from 0-100 were evaluated; higher scores indicated better QoL. Results: Participants were 50% male and 68.1% Caucasian. Prevalence of RLS was 8.4% (n = 18). RLS was associated with trouble falling asleep (OR = 3.1, p = 0.049), and trouble falling asleep was associated with worse Psychosocial Health scores (Coeff. −5.6, p = 0.004) and Total Scale scores for quality of life (Coeff. −4.6, p = 0.007). Conclusions: The prevalence of symptoms consistent with RLS in this community-based sample of adolescents and young adults, aged 12-20, is comparable to rates reported in older cohorts. Symptoms consistent with RLS may be associated with trouble falling asleep and psychosocial distress that may contribute to a lower health-related quality of life. Citation: Silva GE, Goodwin JL, Vana KD, Vasquez MM, Wilcox PG, Quan SF. Restless legs syndrome, sleep, and quality of life among adolescents and young adults. J Clin Sleep Med 2014;10(7):779-786. PMID:25024656

  8. Prevalence of restless legs syndrome in somatoform pain disorder and its effect on quality of life

    PubMed Central

    Chatterjee, Seshadri Sekhar; Mitra, Sayantanava; Guha, Prathama; Chakraborty, Kaustav

    2015-01-01

    Background: Persistent somatoform pain disorder (SPD) is a condition in which the patient suffers from persistent, severe and distressing pain; and from associated physical and psychological distress. While presence of restless leg syndrome (RLS) in SPD is understudied, their association might have an impact on general well-being and quality of life (QoL) in SPD. Aims and Objectives: Present study aimed at evaluating the prevalence of RLS in SPD patients attending outpatient department services at a tertiary care institute in eastern India. Materials and Methods: Two hundred and forty consecutive patients with SPD were screened initially and after applying appropriate inclusion and exclusion criteria, 192 subjects (male = 85, female = 107) were included in the study. Severity of RLS was assessed using a questionnaire of the International Restless Legs Syndrome Study Group and QoL was measured on QoL Enjoyment and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF). Results: Revealed a 28% prevalence of RLS is in patients with SPD, which is much higher than its estimated population prevalence. A larger proportion of those with RLS had continuous course of SPD, longer duration of SPD, and higher daytime sleepiness. They also had poorer scores on Q-LES-Q-SF, indicating a poorer QoL overall. Discussion and Conclusion: This is the first report, to the best of our knowledge, on this aspect from India. While this association between RLS and SPD may have biological explanation based on abnormal monoaminergic neurotransmission system, the findings call for more vigilant approach to SPD patients in order to improve their QoL and add to their well-being. PMID:25883472

  9. The Restless Universe - Understanding X-Ray Astronomy in the Age of Chandra and Newton

    NASA Astrophysics Data System (ADS)

    Schlegel, Eric M.

    2002-10-01

    Carl Sagan once noted that there is only one generation that gets to see things for the first time. We are in the midst of such a time right now, standing on the threshold of discovery in the young and remarkable field of X-ray astronomy. In The Restless Universe , astronomer Eric Schlegel offers readers an informative survey of this cutting-edge science. Two major space observatories launched in the last few years--NASA's Chandra and the European Newton --are now orbiting the Earth, sending back a gold mine of data on the X-ray universe. Schlegel, who has worked on the Chandra project for seven years, describes the building and launching of this space-based X-ray observatory. But the book goes far beyond the story of Chandra . What Schlegel provides here is the background a nonscientist would need to grasp the present and follow the future of X-ray astronomy. He looks at the relatively brief history of the field, the hardware used to detect X-rays, the satellites--past, present, and future--that have been or will be flown to collect the data, the way astronomers interpret this data, and, perhaps most important, the insights we have already learned as well as speculations about what we may soon discover. And throughout the book, Schlegel conveys the excitement of looking at the universe from the perspective brought by these new observatories and the sharper view they deliver. Drawing on observations obtained from Chandra, Newton , and previous X-ray observatories, The Restless Universe gives a first look at an exciting field which significantly enriches our understanding of the universe.

  10. Lack of Association between Genetic Risk Loci for Restless Legs Syndrome and Multimorbidity

    PubMed Central

    Szentkirályi, András; Völzke, Henry; Hoffmann, Wolfgang; Winkelmann, Julianne; Berger, Klaus

    2016-01-01

    Study Objectives: Multimorbidity is a risk factor for incident restless legs syndrome (RLS). In this relationship, the potential role of known genetic risk loci for RLS has not been studied. Our aim was to evaluate whether carriers of specific RLS risk alleles have higher comorbidity burden than noncarriers. Methods: The Dortmund Health Study (DHS) and the Study of Health in Pomerania (SHIP) are two independent cohort studies in Germany based on agestratified, random samples drawn from the respective population registers. DHS included 1,312 subjects and SHIP included 4,308 subjects. RLS status was assessed according to the RLS standard minimal criteria. A comorbidity index was calculated by summing the scores of the following conditions: diabetes, hypertension, myocardial infarction, obesity, stroke, cancer, renal disease, anemia, depression, thyroid disease, and migraine. Thirteen single nucleotide polymorphisms (SNP) previously associated with elevated risk of RLS were genotyped. Analyses were carried out on the pooled sample of the two studies. Results: The mean age was 50.4 ± 15.9 y, and the proportion of women was 51.4%. The mean number of comorbid conditions was 1.5 ± 1.3. In multivariable regression, the mean number of comorbidities was not significantly different between carriers of any of the RLS risk alleles and noncarriers either in the total pooled sample or in those having RLS symptoms. Conclusions: Based on these results it is unlikely that known genetic risk factors for RLS would lead to increased multimorbidity. Citation: Szentkirályi A, Völzke H, Hoffmann W, Winkelmann J, Berger K. Lack of association between genetic risk loci for restless legs syndrome and multimorbidity. SLEEP 2016;39(1):111–115. PMID:26350469

  11. Restless Nocturnal Eating: A Common Feature of Willis-Ekbom Syndrome (RLS)

    PubMed Central

    Howell, Michael J.; Schenck, Carlos H.

    2012-01-01

    Study Objectives: To determine the frequency of nocturnal eating (NE) and sleep related eating disorder (SRED) in restless legs syndrome (RLS) versus psychophysiological insomnia (INS), and the relationship of these conditions with dopaminergic and sedative-hypnotic medications. Design: Prospective case series. Setting: Sleep disorders center. Patients: Newly diagnosed RLS or INS. Intervention: RLS or INS pharmacotherapy with systematic follow up interview for NE/SRED. Measurements and Results: Patients presenting with RLS (n = 88) or INS (n = 42) were queried for the presence of NE and SRED. RLS patients described nocturnal eating (61%) and SRED (36%) more frequently than INS patients (12% and 0%; both p < 0.0001). These findings were not due to arousal frequency, as INS patients were more likely to have prolonged nightly awakenings (93%) than RLS patients (64%; p = 0.003). Among patients on sedative-hypnotics, amnestic SRED and sleepwalking were more common in the setting of RLS (80%) than INS (8%; p < 0.0001). Further, NE and SRED in RLS were not secondary to dopaminergic therapy, as RLS patients demonstrated a substantial drop (68% to 34%; p = 0.0026) in the frequency of NE after dopamine agents were initiated, and there were no cases of dopaminergic agents inducing novel NE or SRED. Conclusion: NE is common in RLS and not due to frequent nocturnal awakenings or dopaminergic agents. Amnestic SRED occurs predominantly in the setting of RLS mistreatment with sedating agents. In light of previous reports, these findings suggest that nocturnal eating is a non-motor manifestation of RLS with several clinical implications discussed here. Citation: Howell MJ; Schenck CH. Restless nocturnal eating: a common feature of Willis-Ekbom Syndrome (RLS). J Clin Sleep Med 2012;8(4):413-419. PMID:22893772

  12. Impact of Short Daily Hemodialysis on Restless Legs Symptoms and Sleep Disturbances

    PubMed Central

    Schiller, Brigitte; Burkart, John M.; Daoui, Rachid; Kraus, Michael A.; Lee, Yoojin; Miller, Brent W.; Teitelbaum, Isaac; Williams, Amy W.; Finkelstein, Fredric O.

    2011-01-01

    Summary Background and objectives Restless legs syndrome (RLS) and sleep disturbances are common among in-center hemodialysis patients and are associated with increased morbidity/mortality. Design, setting, participants, & measurements The FREEDOM study is an ongoing prospective cohort study investigating the benefits of home short daily hemodialysis (SDHD) (6 times/week). In this interim report, we examine the long-term effect of SDHD on the prevalence and severity of RLS, as measured by the International Restless Legs Syndrome (IRLS) Study Group rating scale, and sleep disturbances, as measured by the Medical Outcomes Study sleep survey. Results 235 participants were included in this report (intention-to-treat cohort), of which 127 completed the 12-month follow-up (per-protocol cohort). Mean age was 52 years, 55% had an arteriovenous fistula, and 40% suffered from RLS. In the per-protocol analysis, among patients with RLS, the mean IRLS score improved significantly at month 12, after adjustment for use of RLS-related medications (18 versus 11). Among patients with moderate-to-severe RLS (IRLS score ≥15), there was an even greater improvement in the IRLS score (23 versus 13). The intention-to-treat analysis yielded similar results. Over 12 months, there was decline in the percentage of patients reporting RLS (35% versus 26%) and those reporting moderate-to-severe RLS (59% versus 43%). There was a similar and sustained 12-month improvement in several scales of the sleep survey, after adjustment for presence of RLS and use of anxiolytics and hypnotics. Conclusions Home SDHD is associated with long-term improvement in the prevalence and severity of RLS and sleep disturbances. PMID:21415315

  13. Magnitude-Dependent Seismic Quiescence: A Meta-Analysis of Data and Numerical Simulations of the Underlying Physics

    NASA Astrophysics Data System (ADS)

    Smith, D. E.; Sacks, S. I.

    2013-12-01

    Magnitude-dependent seismic quiescence, the slowing down or ceasing of background seismicity above a threshold magnitude prior to a major earthquake, has been observed for many earthquakes including the 1982 Urakawa-Oki [Taylor et al., 1991] and the 1994 Hokkaido-Toho-Oki [Takanami et al., 1996] in Japan, and the 1994 Northridge earthquake in California [Smith and Sacks, 2013 submitted]. Magnitude-dependent quiescence is a more robust observation than simple quiescence, because the cessation of seismicity in certain magnitude bins but not others, allows one to rule out overall fluctuations in seismicity rate as a source of the signal. We postulate that the mechanism behind magnitude-dependent quiescence involves dilatant expansion of stress asperities in the medium. Under high stress, rock will dilate or volumetrically expand, which will lower the pore pressure and increase the effective normal stress in a water-saturated medium. These higher stress asperities, which tend to release a large stress drop and shear strain energy into the medium when they fail, now become locked due to the increased normal stress. Based on the model of Rydelek and Sacks [1995], which modeled the fault surface as a set of interacting small segments (roughly equivalent in size to the inner-scale of fault roughness), we have seen that events above a threshold magnitude require the failure of a number segments; hence, the clamping of high stress asperities should have the effect of quieting down and ceasing events above a threshold magnitude, since it is the failure of high stress asperities that is most likely to propagate rupture to other segments. We investigate this hypothesized model via: 1) A meta-analysis of data and 2) a numerical model. In the meta-analysis, we examine regions of high deviatoric stress to see how well their behavior agrees with the postulate. Indeed, virtually every observation of quiescence occurs in a compressional environment with a relatively high shear stress

  14. Gab1 and Mapk Signaling Are Essential in the Hair Cycle and Hair Follicle Stem Cell Quiescence.

    PubMed

    Akilli Öztürk, Özlem; Pakula, Hubert; Chmielowiec, Jolanta; Qi, Jingjing; Stein, Simone; Lan, Linxiang; Sasaki, Yoshiteru; Rajewsky, Klaus; Birchmeier, Walter

    2015-10-20

    Gab1 is a scaffold protein that acts downstream of receptor tyrosine kinases. Here, we produced conditional Gab1 mutant mice (by K14- and Krox20-cre) and show that Gab1 mediates crucial signals in the control of both the hair cycle and the self-renewal of hair follicle stem cells. Remarkably, mutant hair follicles do not enter catagen, the destructive phase of the hair cycle. Instead, hair follicle stem cells lose quiescence and become exhausted, and thus no stem cell niches are established in the bulges. Moreover, conditional sustained activation of Mapk signaling by expression of a gain-of-function Mek1(DD) allele (by Krox20-cre) rescues hair cycle deficits and restores quiescence of the stem cells. Our data thus demonstrate an essential role of Gab1 downstream of receptor tyrosine kinases and upstream of Shp2 and Mapk in the regulation of the hair cycle and the self-renewal of hair follicle stem cells.

  15. Msa1 and Msa2 Modulate G1-Specific Transcription to Promote G1 Arrest and the Transition to Quiescence in Budding Yeast

    PubMed Central

    Miles, Shawna; Croxford, Matthew W.; Abeysinghe, Amali P.; Breeden, Linda L.

    2016-01-01

    Yeast that naturally exhaust their glucose source can enter a quiescent state that is characterized by reduced cell size, and high cell density, stress tolerance and longevity. The transition to quiescence involves highly asymmetric cell divisions, dramatic reprogramming of transcription and global changes in chromatin structure and chromosome topology. Cells enter quiescence from G1 and we find that there is a positive correlation between the length of G1 and the yield of quiescent cells. The Swi4 and Swi6 transcription factors, which form the SBF transcription complex and promote the G1 to S transition in cycling cells, are also critical for the transition to quiescence. Swi6 forms a second complex with Mbp1 (MBF), which is not required for quiescence. These are the functional analogues of the E2F complexes of higher eukaryotes. Loss of the RB analogue, Whi5, and the related protein Srl3/Whi7, delays G1 arrest, but it also delays recovery from quiescence. Two MBF- and SBF-Associated proteins have been identified that have little effect on SBF or MBF activity in cycling cells. We show that these two related proteins, Msa1 and Msa2, are specifically required for the transition to quiescence. Like the E2F complexes that are quiescence-specific, Msa1 and Msa2 are required to repress the transcription of many SBF target genes, including SWI4, the CLN2 cyclin and histones, specifically after glucose is exhausted from the media. They also activate transcription of many MBF target genes. msa1msa2 cells fail to G1 arrest and rapidly lose viability upon glucose exhaustion. msa1msa2 mutants that survive this transition are very large, but they attain the same thermo-tolerance and longevity of wild type quiescent cells. This indicates that Msa1 and Msa2 are required for successful transition to quiescence, but not for the maintenance of that state. PMID:27272642

  16. Msa1 and Msa2 Modulate G1-Specific Transcription to Promote G1 Arrest and the Transition to Quiescence in Budding Yeast.

    PubMed

    Miles, Shawna; Croxford, Matthew W; Abeysinghe, Amali P; Breeden, Linda L

    2016-06-01

    Yeast that naturally exhaust their glucose source can enter a quiescent state that is characterized by reduced cell size, and high cell density, stress tolerance and longevity. The transition to quiescence involves highly asymmetric cell divisions, dramatic reprogramming of transcription and global changes in chromatin structure and chromosome topology. Cells enter quiescence from G1 and we find that there is a positive correlation between the length of G1 and the yield of quiescent cells. The Swi4 and Swi6 transcription factors, which form the SBF transcription complex and promote the G1 to S transition in cycling cells, are also critical for the transition to quiescence. Swi6 forms a second complex with Mbp1 (MBF), which is not required for quiescence. These are the functional analogues of the E2F complexes of higher eukaryotes. Loss of the RB analogue, Whi5, and the related protein Srl3/Whi7, delays G1 arrest, but it also delays recovery from quiescence. Two MBF- and SBF-Associated proteins have been identified that have little effect on SBF or MBF activity in cycling cells. We show that these two related proteins, Msa1 and Msa2, are specifically required for the transition to quiescence. Like the E2F complexes that are quiescence-specific, Msa1 and Msa2 are required to repress the transcription of many SBF target genes, including SWI4, the CLN2 cyclin and histones, specifically after glucose is exhausted from the media. They also activate transcription of many MBF target genes. msa1msa2 cells fail to G1 arrest and rapidly lose viability upon glucose exhaustion. msa1msa2 mutants that survive this transition are very large, but they attain the same thermo-tolerance and longevity of wild type quiescent cells. This indicates that Msa1 and Msa2 are required for successful transition to quiescence, but not for the maintenance of that state. PMID:27272642

  17. a New Approach of the Deflagration to Detonation Transition in SNIa Thermonuclear Supernovae

    NASA Astrophysics Data System (ADS)

    Chièze, Jean Pierre; Charignon, Camille

    2015-03-01

    A wide class of type Ia thermonuclear supernovae models relies on the transition from the subsonic deflagration combustion regime to the supersonic detonation regime of the carbon and oxygen mixture of an accreting white dwarf, near the Chandrasekhar mass. We show that this can actually be achieved in a cold C+O white dwarf near the Chandrasekhar mass, with seed sound waves of relatively low Mach number M ˜ 0.02. Moreover, even weaker perturbations, with velocity perturbations as low as M ˜ 0.003 can trigger a detonation wave in SNIa progenitors models wich include the presence of a thin helium surface layer.

  18. The use of idle equipment for ITER (International Thermonuclear Engineering Reactor) magnet development

    SciTech Connect

    Miller, J.R.

    1988-07-11

    Test facilities that can be effectively applied to International Thermonuclear Engineering Reactor (ITER) magnet needs are scarce because the costs and the time required to produce them from the ground up tend to be prohibitive. It has been proposed as an option that several unique and valuable pieces of equipment that are already owned by the DOE be consolidated into the Lawrence Livermore National High Field Test Facility (HFTF) which may be uniquely qualified to make effective use of them. 6 figs., 4 tabs.

  19. 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.

  20. Pilot experiments for the International Thermonuclear Experimental Reactor active beam spectroscopy diagnostic

    NASA Astrophysics Data System (ADS)

    Hellermann, M. von; Bock, M. de; Jaspers, R.; Jakubowska, K.; Barnsley, R.; Giroud, C.; Hawkes, N. C.; Zastrow, K. D.; Lotte, P.; Giannella, R.; Malaquias, A.; Rachlew, E.; Tugarinov, S.; Krasilnikov, A.; Litnovsky, A.; Philipps, V.; Wienhold, P.; Oelhafen, P.; Temmerman, G. De; Shmaenok, L.

    2004-10-01

    Supporting pilot experiments and activities which are currently considered or already performed for the development of the International Thermonuclear Experiment Reactor active beam spectroscopy diagnostic are addressed in this article. Four key issues are presented including optimization of spectral instrumentation, feasibility of a motional Stark effect (MSE) evaluation based on line ratios, "first-mirror" test-bed experiments at the tokamak TEXTOR, and finally the role of integrated data analysis for the conceptual layout of the change exchange recombination spectroscopy and MSE diagnostic.

  1. Necdin, a p53 target gene, regulates the quiescence and response to genotoxic stress of hematopoietic stem/progenitor cells.

    PubMed

    Asai, Takashi; Liu, Yan; Di Giandomenico, Silvana; Bae, Narae; Ndiaye-Lobry, Delphine; Deblasio, Anthony; Menendez, Silvia; Antipin, Yevgeniy; Reva, Boris; Wevrick, Rachel; Nimer, Stephen D

    2012-08-23

    We recently defined a critical role for p53 in regulating the quiescence of adult hematopoietic stem cells (HSCs) and identified necdin as a candidate p53 target gene. Necdin is a growth-suppressing protein and the gene encoding it is one of several that are deleted in patients with Prader-Willi syndrome. To define the intrinsic role of necdin in adult hematopoiesis, in the present study, we transplanted necdin-null fetal liver cells into lethally irradiated recipients. We show that necdin-null adult HSCs are less quiescent and more proliferative than normal HSCs, demonstrating the similar role of necdin and p53 in promoting HSC quiescence during steady-state conditions. However, wild-type recipients repopulated with necdin-null hematopoietic stem/progenitor cells show enhanced sensitivity to irradiation and chemotherapy, with increased p53-dependent apoptosis, myelosuppression, and mortality. Necdin controls the HSC response to genotoxic stress via both cell-cycle-dependent and cell-cycle-independent mechanisms, with the latter occurring in a Gas2L3-dependent manner. We conclude that necdin functions as a molecular switch in adult hematopoiesis, acting in a p53-like manner to promote HSC quiescence in the steady state, but suppressing p53-dependent apoptosis in response to genotoxic stress.

  2. Detection of Cardiac Quiescence from B-Mode Echocardiography Using a Correlation-Based Frame-to-Frame Deviation Measure

    PubMed Central

    Mcclellan, James H.; Ravichandran, Lakshminarayan; Tridandapani, Srini

    2013-01-01

    Two novel methods for detecting cardiac quiescent phases from B-mode echocardiography using a correlation-based frame-to-frame deviation measure were developed. Accurate knowledge of cardiac quiescence is crucial to the performance of many imaging modalities, including computed tomography coronary angiography (CTCA). Synchronous electrocardiography (ECG) and echocardiography data were obtained from 10 healthy human subjects (four male, six female, 23–45 years) and the interventricular septum (IVS) was observed using the apical four-chamber echocardiographic view. The velocity of the IVS was derived from active contour tracking and verified using tissue Doppler imaging echocardiography methods. In turn, the frame-to-frame deviation methods for identifying quiescence of the IVS were verified using active contour tracking. The timing of the diastolic quiescent phase was found to exhibit both inter- and intra-subject variability, suggesting that the current method of CTCA gating based on the ECG is suboptimal and that gating based on signals derived from cardiac motion are likely more accurate in predicting quiescence for cardiac imaging. Two robust and efficient methods for identifying cardiac quiescent phases from B-mode echocardiographic data were developed and verified. The methods presented in this paper will be used to develop new CTCA gating techniques and quantify the resulting potential improvement in CTCA image quality. PMID:26609501

  3. Foxp1 maintains hair follicle stem cell quiescence through regulation of Fgf18

    PubMed Central

    Leishman, Erin; Howard, Jeffrey M.; Garcia, Gloria E.; Miao, Qi; Ku, Amy T.; Dekker, Joseph D.; Tucker, Haley; Nguyen, Hoang

    2013-01-01

    Hair follicles cyclically degenerate and regenerate throughout adult life and require regular stem cell activation to drive the cycle. In the resting phase of the hair cycle, hair follicle stem cells are maintained in a quiescent state until they receive signals to proliferate. We found that the forkhead transcription factor Foxp1 is crucial for maintaining the quiescence of hair follicle stem cells. Loss of Foxp1 in skin epithelial cells leads to precocious stem cell activation, resulting in drastic shortening of the quiescent phase of the hair cycle. Conversely, overexpression of Foxp1 in keratinocytes prevents cell proliferation by promoting cell cycle arrest. Finally, through both gain- and loss-of-function studies, we identify fibroblast growth factor 18 (Fgf18) as the key downstream target of Foxp1. We show that exogenously supplied FGF18 can prevent the hair follicle stem cells of Foxp1 null mice from being prematurely activated. As Fgf18 controls the length of the quiescent phase and is a key downstream target of Foxp1, our data strongly suggest that Foxp1 regulates the quiescent stem cell state in the hair follicle stem cell niche by controlling Fgf18 expression. PMID:23946441

  4. Autophagy is required for G₁/G₀ quiescence in response to nitrogen starvation in Saccharomyces cerevisiae.

    PubMed

    An, Zhenyi; Tassa, Amina; Thomas, Collin; Zhong, Rui; Xiao, Guanghua; Fotedar, Rati; Tu, Benjamin P; Klionsky, Daniel J; Levine, Beth

    2014-10-01

    In response to starvation, cells undergo increased levels of autophagy and cell cycle arrest but the role of autophagy in starvation-induced cell cycle arrest is not fully understood. Here we show that autophagy genes regulate cell cycle arrest in the budding yeast Saccharomyces cerevisiae during nitrogen starvation. While exponentially growing wild-type yeasts preferentially arrest in G₁/G₀ in response to starvation, yeasts carrying null mutations in autophagy genes show a significantly higher percentage of cells in G₂/M. In these autophagy-deficient yeast strains, starvation elicits physiological properties associated with quiescence, such as Snf1 activation, glycogen and trehalose accumulation as well as heat-shock resistance. However, while nutrient-starved wild-type yeasts finish the G₂/M transition and arrest in G₁/G 0₀ autophagy-deficient yeasts arrest in telophase. Our results suggest that autophagy is crucial for mitotic exit during starvation and appropriate entry into a G₁/G₀ quiescent state.

  5. The First X-ray Measurement Of SAX J1750.8-2900 In Quiescence

    NASA Astrophysics Data System (ADS)

    Lowell, Alexander W.; Tomsick, J.; Bodaghee, A.; Boggs, S.; Heinke, C.; Kaaret, P.; Chaty, S.; Rodriguez, J.; Walter, R.

    2011-09-01

    We have performed the first sensitive X-ray observation of the low-mass X-ray binary (LMXB) SAX J1750.8-2900 in quiescence with XMM-Newton. Both a classical black body model and a non-magnetized, pure hydrogen neutron star (NS) atmosphere model were fit to the 0.3-12.0 keV spectrum. In addition, a power law component was added to the model in order to search for evidence of harder emission not accounted for by the thermal component. Assuming a previously measured upper limit on the distance to SAX J1750.8-2900 of 6.3 +/- 0.7 kpc, we find that the upper limit for the luminosity of this source is 8.1 (+1.9) (-1.8) E33 erg/s for the NS atmosphere model, and 2.3 (+0.9) (-0.5) E33 erg/s for the black body model. We conclude that the power law contribution to the total luminosity is low, and we discuss implications for the origin of the power-law that is present in some systems. Although many quiescent NS transients show evidence for enhanced cooling, the quiescent luminosity for SAX J1750.8-2900 may be high enough that the standard cooling scenario may be sufficient.

  6. Angiography of the corpus cavernosum penis in the pony stallion during erection and quiescence.

    PubMed

    Bartels, J E; Beckett, S D; Brown, B G

    1984-07-01

    Serial arteriography was used to determine the vascular pattern and blood flow in the penis of the pony stallion. Ponies were anesthetized with pentobarbital sodium, and catheters were surgically introduced into the internal pudendal and obturator arteries. The vascular anatomy was visualized by angiography via image-intensified fluoroscopy and was recorded on 70-mm film at 3 frames/s or by direct radiography. Blood flow into the corpus cavernosum penis (CCP) was limited during quiescence because the blood was immediately shunted into the venous system. After vasodilation with mild stimulation from an electroejaculator, there was increased filling of the CCP and corpus spongiosum penis. Contrast medium injected into the internal pudendal artery entered the bulb of the penis during peak erection, but medium injected into the obturator artery could not enter the crus penis during peak erection. The contrast medium stopped in the obturator artery at the edge of the ischiocavernous muscles due to the occlusion of the deep arteries of the penis by contraction of these muscles. When contrast medium was injected directly into the CCP near the glans to outline the body of the penis, there was no evidence of venous outlets along the body.

  7. Endodermal ABA signaling promotes lateral root quiescence during salt stress in Arabidopsis seedlings.

    PubMed

    Duan, Lina; Dietrich, Daniela; Ng, Chong Han; Chan, Penny Mei Yeen; Bhalerao, Rishikesh; Bennett, Malcolm J; Dinneny, José R

    2013-01-01

    The endodermal tissue layer is found in the roots of vascular plants and functions as a semipermeable barrier, regulating the transport of solutes from the soil into the vascular stream. As a gateway for solutes, the endodermis may also serve as an important site for sensing and responding to useful or toxic substances in the environment. Here, we show that high salinity, an environmental stress widely impacting agricultural land, regulates growth of the seedling root system through a signaling network operating primarily in the endodermis. We report that salt stress induces an extended quiescent phase in postemergence lateral roots (LRs) whereby the rate of growth is suppressed for several days before recovery begins. Quiescence is correlated with sustained abscisic acid (ABA) response in LRs and is dependent upon genes necessary for ABA biosynthesis, signaling, and transcriptional regulation. We use a tissue-specific strategy to identify the key cell layers where ABA signaling acts to regulate growth. In the endodermis, misexpression of the ABA insensitive1-1 mutant protein, which dominantly inhibits ABA signaling, leads to a substantial recovery in LR growth under salt stress conditions. Gibberellic acid signaling, which antagonizes the ABA pathway, also acts primarily in the endodermis, and we define the crosstalk between these two hormones. Our results identify the endodermis as a gateway with an ABA-dependent guard, which prevents root growth into saline environments.

  8. Organization of ribosomes and nucleoids in Escherichia coli cells during growth and in quiescence.

    PubMed

    Chai, Qian; Singh, Bhupender; Peisker, Kristin; Metzendorf, Nicole; Ge, Xueliang; Dasgupta, Santanu; Sanyal, Suparna

    2014-04-18

    We have examined the distribution of ribosomes and nucleoids in live Escherichia coli cells under conditions of growth, division, and in quiescence. In exponentially growing cells translating ribosomes are interspersed among and around the nucleoid lobes, appearing as alternative bands under a fluorescence microscope. In contrast, inactive ribosomes either in stationary phase or after treatment with translation inhibitors such as chloramphenicol, tetracycline, and streptomycin gather predominantly at the cell poles and boundaries with concomitant compaction of the nucleoid. However, under all conditions, spatial segregation of the ribosomes and the nucleoids is well maintained. In dividing cells, ribosomes accumulate on both sides of the FtsZ ring at the mid cell. However, the distribution of the ribosomes among the new daughter cells is often unequal. Both the shape of the nucleoid and the pattern of ribosome distribution are also modified when the cells are exposed to rifampicin (transcription inhibitor), nalidixic acid (gyrase inhibitor), or A22 (MreB-cytoskeleton disruptor). Thus we conclude that the intracellular organization of the ribosomes and the nucleoids in bacteria are dynamic and critically dependent on cellular growth processes (replication, transcription, and translation) as well as on the integrity of the MreB cytoskeleton.

  9. Quiescence Loosens Epigenetic Constraints in Bovine Somatic Cells and Improves Their Reprogramming into Totipotency.

    PubMed

    Kallingappa, Prasanna K; Turner, Pavla M; Eichenlaub, Michael P; Green, Andria L; Oback, Fleur C; Chibnall, Alice M; Wells, David N; Oback, Björn

    2016-07-01

    Reprogramming by nuclear transfer (NT) cloning forces cells to lose their lineage-specific epigenetic marks and reacquire totipotency. This process often produces molecular anomalies that compromise clone development. We hypothesized that quiescence alters the epigenetic status of somatic NT donor cells and elevates their reprogrammability. To test this idea, we compared chromatin composition and cloning efficiency of serum-starved quiescent (G0) fibroblasts versus nonstarved mitotically selected (G1) controls. We show that G0 chromatin contains reduced levels of Polycomb group proteins EED, SUZ12, PHC1, and RING2, as well as histone variant H2A.Z. Using quantitative confocal immunofluorescence microscopy and fluorometric enzyme-linked immunosorbent assay, we further show that G0 induced DNA and histone hypomethylation, specifically at H3K4me3, H3K9me2/3 and H3K27me3, but not H3K9me1. Collectively, these changes resulted in a more relaxed G0 chromatin state. Following NT, G0 donors developed into blastocysts that retained H3K9me3 hypomethylation, both in the inner cell mass and trophectoderm. G0 blastocysts from different cell types and cell lines developed significantly better into adult offspring. In conclusion, serum starvation induced epigenetic changes, specifically hypotrimethylation, that provide a mechanistic correlate for increased somatic cell reprogrammability. PMID:27281704

  10. SUZAKU OBSERVATION OF THE CLASSICAL NOVA V2491 Cyg IN QUIESCENCE

    SciTech Connect

    Zemko, P.; Mukai, K.; Orio, M. E-mail: koji.mukai@umbc.edu

    2015-07-01

    We present the Suzaku XIS observation of V2491 Cyg (Nova Cyg 2008 No. 2) obtained in quiescence, more than two years after the outburst. The nova was detected as a very luminous source in a wide spectral range from soft to hard X-rays. A very soft blackbody-like component peaking at 0.5 keV indicates that we observe either remaining, localized hydrogen burning on the surface of the white dwarf, or accretion onto a magnetized polar cap. In the second case, V2491 Cyg is a candidate “soft intermediate polar.” We obtained the best fit for the X-ray spectra with several components: two of thermal plasma, a blackbody and a complex absorber. The latter is typical of intermediate polars. The X-ray light curve shows a modulation with a period of ∼38 minutes. The amplitude of this modulation is strongly energy-dependent and reaches a maximum in the range 0.8–2.0 keV. We discuss the origin of the X-ray emission and pulsations, and the likelihood of the intermediate polar scenario.

  11. Loss of Quiescence in von Hippel-Lindau Hemangioblastomas is Associated with Erythropoietin Signaling

    PubMed Central

    Feldman, Michael J.; Sizdahkhani, Saman; Edwards, Nancy A.; Merrill, Marsha J.; Ray-Chaudhury, Abhik; Zhuang, Zhengping; Lonser, Russell R.; Oldfield, Edward H.; Chittiboina, Prashant

    2016-01-01

    von Hippel-Lindau (VHL) patients develop multiple central nervous system hemangioblastomas (HB). Some HBs become symptomatic with exponential growth or cyst formation following long periods of quiescence. Understanding the factors underlying growth in hemangioblastoma may lead to better strategies to arrest or prevent tumor growth. In 5 VHL patients, we resected quiescent hemangioblastomas (Q-HB) that were en-route during surgical access to symptomatic hemangioblastomas (S-HB), for matched tumor analysis. Quantitative reverse transcriptase analysis demonstrated a 2-fold increase in EPO expression in all S-HB, while 4/5 showed either Hypoxia Inducible Factor-1α or 2α upregulation. Additionally, all S-HB had increased phosphorylated erythropoietin (EPO) receptor and phosphorylated STAT-5 relative to matched Q-HB, with increased phosphorylated JAK-2 largely confined to the stromal cells in clusters within the tumors. These findings suggest that Q-HB to S-HB conversion may be associated with an erythropoietin-signaling loop. Furthermore, we found that EPO is detectable in cyst fluid from S-HB (n = 14), while absent in CSF (n = 1). Additionally, S-HB presentation or S-HB resection does not result in discernible change in serum EPO or hemoglobin (n = 60). These observations suggest that the altered erythropoietin signaling is focal and suggests that studying modulation of erythropoietin receptor pathway may lead to strategies in preventing HB growth. PMID:27748427

  12. Infrared accretion disc mapping of the dwarf nova V2051 Ophiuchi in outburst and in quiescence

    NASA Astrophysics Data System (ADS)

    Wojcikiewicz, E.; Baptista, R.

    2014-10-01

    Dwarf novae are compact binaries where a late-type star (the secondary) fills its Roche lobe and transfers matter to a companion white dwarf (the primary) via an accretion disc. They show outbursts which recur on timescales of weeks to years, where the accretion disc brightens by factors 20 to 100 either due to a thermal-viscous instability in the disc (DI model) or to a burst of enhanced mass-transfer from the secondary (MTI model). We report time-series of fast photometry of the dwarf nova V2051 Oph in the J and H bands, obtained with the CAMIV at the 1.6 m telescope of Observatório Pico dos Dias/Brazil, during the decline of an outburst in 2005 June, and in 2008 when the object was in quiescence. We modeled the ellipsoidal variations caused by the secondary to infer its contribution to the J and H fluxes, and fitted stellar atmosphere models to find a photometric parallatic distance of d = (111± 14)pc. Front-back brightness asymmetries in J and H-band eclipse maps along the decline from the 2005 outburst suggest that the accretion disc had a non-negligible opening angle which decreased as the disc cooled down. The time evolution of the disc radial temperature distribution along the outburst decline shows a cooling wave which accelerates as is travels inwards - in contradiction to a basic prediction from the DI model.

  13. Suzaku Observation of the Classical Nova V2491 Cyg in Quiescence

    NASA Technical Reports Server (NTRS)

    Zemko, P.; Mukai, K.; Orio, M.

    2015-01-01

    We present Suzaku XIS observation of V2491 Cyg (Nova Cyg 2008 No. 2) obtained in quiescence, more than two years after the outburst. The nova was detected as a very luminous source in a wide spectral range from soft to hard X-rays. A very soft blackbody-like component peaking at 0.5 keV indicates that either we observe remaining, localized hydrogen burning on the surface of the white dwarf, or accretion onto a magnetized polar cap. In the second case, V2491 Cyg is a candidate "soft intermediate polar". We obtained the best fit for the X-ray spectra with several components: two of thermal plasma, a blackbody and a complex absorber. The later is typical of intermediate polars. The X-ray light-curve shows a modulation with an approximately 38 min period. The amplitude of this modulation is strongly energy dependent and reaches maximum in the 0.8-2.0 keV range. We discuss the origin of the X-ray emission and pulsations, and the likelihood of the intermediate polar scenario.

  14. Skeletal muscle stem cells express anti-apoptotic ErbB receptors during activation from quiescence

    SciTech Connect

    Golding, Jon P. . E-mail: j.p.golding@open.ac.uk; Calderbank, Emma; Partridge, Terence A.; Beauchamp, Jonathan R.

    2007-01-15

    To be effective for tissue repair, satellite cells (the stem cells of adult muscle) must survive the initial activation from quiescence. Using an in vitro model of satellite cell activation, we show that erbB1, erbB2 and erbB3, members of the EGF receptor tyrosine kinase family, appear on satellite cells within 6 h of activation. We show that signalling via erbB2 provides an anti-apoptotic survival mechanism for satellite cells during the first 24 h, as they progress to a proliferative state. Inhibition of erbB2 signalling with AG825 reduced satellite cell numbers, concomitant with elevated caspase-8 activation and TUNEL labelling of apoptotic satellite cells. In serum-free conditions, satellite cell apoptosis could be largely prevented by a mixture of erbB1, erbB3 and erbB4 ligand growth factors, but not by neuregulin alone (erbB3/erbB4 ligand). Furthermore, using inhibitors specific to discrete intracellular signalling pathways, we identify MEK as a pro-apoptotic mediator, and the erbB-regulated factor STAT3 as an anti-apoptotic mediator during satellite cell activation. These results implicate erbB2 signalling in the preservation of a full compliment of satellite cells as they activate in the context of a damaged muscle.

  15. Cancer Stem Cell Quiescence and Plasticity as Major Challenges in Cancer Therapy

    PubMed Central

    Chen, Wanyin; Dong, Jihu; Haiech, Jacques; Kilhoffer, Marie-Claude

    2016-01-01

    Cells with stem-like properties, tumorigenic potential, and treatment-resistant phenotypes have been identified in many human malignancies. Based on the properties they share with nonneoplastic stem cells or their ability to initiate and propagate tumors in vivo, such cells were designated as cancer stem (stem-like) or tumor initiating/propagating cells. Owing to their implication in treatment resistance, cancer stem cells (CSCs) have been the subject of intense investigation in past years. Comprehension of CSCs' intrinsic properties and mechanisms they develop to survive and even enhance their aggressive phenotype within the hostile conditions of the tumor microenvironment has reoriented therapeutic strategies to fight cancer. This report provides selected examples of malignancies in which the presence of CSCs has been evidenced and briefly discusses methods to identify, isolate, and functionally characterize the CSC subpopulation of cancer cells. Relevant biological targets in CSCs, their link to treatment resistance, proposed targeting strategies, and limitations of these approaches are presented. Two major aspects of CSC physiopathology, namely, relative in vivo quiescence and plasticity in response to microenvironmental cues or treatment, are highlighted. Implications of these findings in the context of the development of new therapies are discussed. PMID:27418931

  16. Tubal Ligation Induces Quiescence in the Epithelia of the Fallopian Tube Fimbria.

    PubMed

    Tiourin, Ekaterina; Velasco, Victor S; Rosales, Miguel A; Sullivan, Peggy S; Janzen, Deanna M; Memarzadeh, Sanaz

    2015-10-01

    Tubal ligation keeps the fimbriated end of the fallopian tube intact while interrupting the conduit for sperm and egg between the uterus and ovary. Tubal ligation is associated with an approximately 20% decreased risk of high-grade serous ovarian cancers, which mounting evidence suggests arise from the distal fallopian tube epithelium. We postulated that biological changes at the epithelial cellular level of the distal fallopian tube may account for the surgical procedure's observed risk reduction. We compared the histology, presence of epithelial progenitors (basally located CD44-positive cells), and degree of epithelial proliferation (Ki67-positive cells) of distal fallopian tube from 10 patients with previous tubal ligation and 10 age-matched patients with uncut fallopian tubes. A significantly reduced population of proliferating epithelial progenitors (basally located CD44/Ki67 dual-positive cells) was detected in the tubal ligated specimens (P = .0002). To functionally assess the effect of tubal ligation, a murine model was utilized to compare the growth capacity of distal fallopian tube epithelial cells isolated from either ligated or sham-operated tubal epithelia. Murine fallopian tube epithelial cells isolated after tubal ligation showed a significantly reduced capacity to grow organoids in culture compared to sham-operated controls (P = .002). The findings of this study show that tubal ligation is associated with a reduced presence and decreased proliferation of progenitor cells in the distal fallopian tube epithelium. These compositional and functional changes suggest that tubal ligation induces quiescence of distal fallopian tube epithelial cells.

  17. Pregabalin Versus Pramipexole: Effects on Sleep Disturbance in Restless Legs Syndrome

    PubMed Central

    Garcia-Borreguero, Diego; Patrick, Jeffrey; DuBrava, Sarah; Becker, Philip M.; Lankford, Alan; Chen, Crystal; Miceli, Jeffrey; Knapp, Lloyd; Allen, Richard P.

    2014-01-01

    Study Objectives: To compare pregabalin versus placebo and pramipexole for reducing restless legs syndrome (RLS)-related sleep disturbance. Design: Randomized, double-blinded, crossover trial. Setting: Twenty-three US sleep centers. Participants: Eighty-five individuals with moderate to severe idiopathic RLS and associated sleep disturbance. Interventions: Participants were randomized across 6 treatment sequences comprising three 4-week periods on pregabalin 300 mg/day (n = 75), pramipexole 0.5 mg/day (n = 76), or placebo (n = 73). Measurements and Results: Polysomnography was conducted over 2 nights at the end of each period. Primary (wake after sleep onset [WASO], pregabalin vs placebo) and key secondary endpoints were analyzed for statistical significance, with descriptive statistics for other endpoints. Pregabalin improved sleep maintenance, demonstrated by reductions in WASO (-27.1 min vs placebo [P < 0.0001]; -26.9 vs pramipexole) and number of awakenings after sleep onset (-2.7 vs placebo; -7.9 vs pramipexole [P < 0.0001]) by polysomnography, and an increase in subjective total sleep time (30.8 min vs placebo [P < 0.0001]; 26.8 vs pramipexole). Pregabalin also increased slow wave sleep duration (20.9 min vs placebo; 32.1 vs pramipexole [P < 0.0001]). Reduction in periodic limb movement arousal index (PLMAI) with pregabalin was similar to pramipexole and greater than placebo (-3.7 PLMA/h [P < 0.0001]), although reduction in total PLM in sleep was less than for pramipexole. Conclusions: This study demonstrated improvements in objective and subjective measures of sleep maintenance and sleep architecture with pregabalin compared with placebo and pramipexole. Effects of pregabalin on periodic limb movement arousal index were comparable to pramipexole. Trial Registration: ClinicalTrials.gov identifier, NCT00991276; http://clinicaltrials.gov/show/NCT00991276 Citation: Garcia-Borreguero D; Patrick J; DuBrava S; Becker PM; Lankford A; Chen C; Miceli J; Knapp L; Allen

  18. A Four-Year Longitudinal Study on Restless Legs Syndrome in Parkinson Disease

    PubMed Central

    Moccia, Marcello; Erro, Roberto; Picillo, Marina; Santangelo, Gabriella; Spina, Emanuele; Allocca, Roberto; Longo, Katia; Amboni, Marianna; Palladino, Raffaele; Assante, Roberta; Pappatà, Sabina; Pellecchia, Maria Teresa; Barone, Paolo; Vitale, Carmine

    2016-01-01

    Study Objectives: Restless legs syndrome (RLS) prevalence estimates range from 0% to 52% in Parkinson disease (PD), but the causal relationship between the two disorders is still debated. The present study aims to evaluate RLS prevalence in de novo PD subjects, its incidence during the first 4 years from diagnosis, and possible relationships with clinical, laboratory, and neuroradiological data. Methods: One hundred nine newly diagnosed, drug-naïve PD subjects were evaluated at the time of PD diagnosis, and after 2- and 4-years. RLS diagnosis was performed with the RLS Diagnostic Index at each visit. Motor features, additional non-motor symptoms (NMS), and concomitant dopaminergic and nondopaminergic treatments were also gathered. Moreover, at baseline, 65 subjects were randomly selected to undergo a FP-CIT SPECT to study dopamine transporter availability. Results: RLS prevalence rose from 4.6% at baseline evaluation to 6.5% after 2 years and to 16.3% after 4 years (P = 0.007). A multinomial logistic stepwise regression model selected NMS Questionnaire items more likely to be associated with RLS at diagnosis (insomnia, OR = 15.555; P = 0.040) and with occurrence of RLS during follow-up (dizziness, OR = 1.153; P = 0.022; and daytime sleepiness; OR = 9.557; P = 0.001), as compared to patients without RLS. Older age was more likely associated to increased RLS occurrence during follow-up in a random effect logistic regression model (OR = 1.187; P = 0.036). A multinomial logistic stepwise model found increased dopaminergic transporter availability of affected caudate and putamen to be more likely associated with RLS presence at diagnosis (n = 5; OR = 75.711; P = 0.077), and RLS occurrence during follow-up (n = 16; OR = 12.004; P = 0.059), respectively, as compared to patients without RLS (n = 88). Conclusions: RLS is present since PD diagnosis, and increases in prevalence during the course of PD. PD subjects with RLS have higher age at PD onset, more preserved

  19. Restless legs syndrome and quality of sleep in patients with glomerulopathy

    PubMed Central

    2013-01-01

    Background Despite a confirmed association between restless legs syndrome (RLS) and end-stage renal disease (ESRD), there is no study on patients presenting with nephrotic syndrome (NS). To investigate the frequency of RLS and poor quality sleep in NS-patients secondary to primary glomerulopathy with nearly normal glomerular filtration rate (GFR) and its associated factors. Methods Patients with NS, defined as 24 h-urine protein greater than 3.5 g/1.73 m2 and hypoalbuminemia, (n = 99, 53 women) and a mean age of 36±11 years were studied. Age and sex-matched controls were used to compare RLS and poor sleep quality prevalence. Standardized RLS questionnaire formulated by the International Restless Legs Syndrome and Pittsburgh Sleep Quality Index (PSQI) were used. Results RLS was more frequent in NS-patients than in controls (22.8 vs. 4.0%, p = 0.01). Mean time since diagnosis (52.2±34.1 vs. 28.6±22.5 months, p < 0.01) and 24 h-proteinuria (3.7±1.3 vs. 2.6±0.6 g/1.73 m2, p = 0.001) were greater in NS-patients with RLS those not presenting RLS. Association between RLS with 24 h-proteinuria [OR = 2.31; p = 0.007; 95% CI 1.87-2.89] and time since diagnosis [OR = 1.10; p = 0.003; CI = 1.02-1.39] were identified even after controlling for age, GFR and diabetes. Sleep quality was poor in NS-patients than in controls (mean PSQI score 7.35±3.7 vs. 5.2±3.0, p = 0.003). In NS-patients, only RLS was associated with poor sleep quality (OR = 1.20; p = 0.004). Conclusion Poor quality sleep and RLS are frequent in NS-patients without ESRD. Pathophysiology of this association must be further investigated. PMID:23710767

  20. 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.

  1. Fault Simulator with Dilatant Effects Used to Investigate Statistics of Foreshocks/Aftershocks, Including Magnitude Dependent Seismic Quiescence

    NASA Astrophysics Data System (ADS)

    Smith, D. E.; Sacks, S. I.; Rydelek, P. A.

    2011-12-01

    We add dilatant effects to a fault simulator to include physics consistent with observations of seismic quiescence. Using this simulator, we examine precursory and aftershock statistics of major events, changes in b-value, correlations between slip and static stress changes, changes in the in-plane focal mechanisms, and temporal decay of aftershocks. Seismic quiescence has been observed for a number major events including, 1982 Urakawa-Oki earthquake [Taylor et al., 1992], 1994 Hokkaido-Toho-Oki earthquake [Takanami et al., 1996], 1994 Northridge earthquake [Smith and Sacks, 2011], 1995 Kobe earthquake [Enescu et al., 2011], 1988 Spitak earthquake [Wysse and Martirosyan, 1998], and 2011 Tohoku earthquake [Katsumata, in press, 2011]. The physics of dilatancy theory [Nur, 1972; Whitcomb et al., 1973; Scholz et al., 1973], which we include in the simulator, is proposed as an explanation for seismic quiescence [Takanami et al., 1996; Scholz, 2000]. As the fault is loaded toward failure and the stress increases, if the stress is sufficiently high, the rock can begin to dilate. As dilation causes an increase in the rock volume, the pore pressure decreases, the effective normal stress increases, and the fault core strengthens [Rice, 1975]. Because the fault core supports more of the stress, the seismicity of the surrounding region will decrease as is observed. Over time (~2-20 years) the water will percolate back into the fault core from the surrounding region. The pore pressure in the fault core increases again, the normal stress decreases, and failure is encouraged. This dilatant effect on the fault core foreshocks, surrounding quiescence zone, and the aftershocks, can be studied by modifying the fault simulator of Sacks and Rydelek [1995]; Rydelek and Sacks [1996]. Based on simple physics: discrete patches, Coulomb failure, and redistribution of stresses on a specified fault geometry, this simulator (without dilatancy) has already been shown to reproduce Gutenberg

  2. Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation-based phase-to-phase deviation measure

    SciTech Connect

    Wick, Carson A.; McClellan, James H.; Arepalli, Chesnal D.; Auffermann, William F.; Henry, Travis S.; Khosa, Faisal; Coy, Adam M.; Tridandapani, Srini

    2015-02-15

    Purpose: Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation-based, phase-to-phase deviation measure was developed. Methods: Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as well as the IVS was calculated using phase-to-phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board-certified radiologists, fellowship-trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic. Results: Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase-to-phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (P{sub AGG}) and IVS (P{sub IV} {sub S}) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (P{sub CT}). The one exception was the RCA, which improved for P{sub AGG} for 18 of the 20 subjects when compared to P

  3. 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

  4. Association of restless legs syndrome with nocturnal eating: a case-control study.

    PubMed

    Provini, Federica; Antelmi, Elena; Vignatelli, Luca; Zaniboni, Anna; Naldi, Giulia; Calandra-Buonaura, Giovanna; Vetrugno, Roberto; Plazzi, Giuseppe; Montagna, Pasquale

    2009-04-30

    We investigated the prevalence of nocturnal eating (sleep-related eating disorder-SRED or night-eating syndrome-NES) in patients with restless legs syndrome (RLS). One hundred RLS patients living in Emilia-Romagna (Northern Italy) and 100 matched controls randomly selected from the general population received two telephone interviews, and were investigated for socio-demographic characteristics, general health status, and presence of nocturnal eating. Additionally, subjects underwent interviews for psychopathological traits [by means of the Eating Disorder Inventory-2 (EDI-2), the Maudsley Obsessive-Compulsive Inventory (MOCI), the Beck Depression Inventory (BDI)], excessive daytime sleepiness (EDS), and subjective sleep quality. Compared with controls, RLS patients had more frequently pathological MOCI scores (24% versus 10%, P = 0.03), used significantly more drugs for concomitant diseases and had more nocturnal sleep impairment and EDS. SRED was more prevalent in RLS patients than controls (SRED: 33% versus 1%, P < 0.001). Medication use and pathological MOCI scores were more prevalent in RLS patients with SRED than among RLS patients without SRED. Use of dopaminergic or hypnotic drugs for RLS was not correlated with the presence of SRED. We demonstrate an association between RLS and SRED. Prospective studies are needed to establish the mechanisms underlying such association and whether it is causal.

  5. Restless legs syndrome in a primary contact setting: a case report

    PubMed Central

    Stupar, Maja

    2008-01-01

    Objective To describe the diagnostic features of a patient who presented to a chiropractor with restless legs syndrome (RLS), a common but often under-diagnosed condition. Clinical Features A 42-year-old male patient presented with twitching and deep pressure in the legs bilaterally; described also as an uncomfortable urge to move the legs that followed a circadian rhythm occurring in the evening. The symptoms were initiated after periods of rest and they were relieved by movement. Physical examination was non-contributory which is common in RLS except in secondary forms of the condition. Discussion The pathophysiology of RLS is still unknown but several treatments have been studied. Non-pharmacologic treatment options include education on improving sleep hygiene, decreasing alcohol and caffeine intake, moderate exercise and supplements. Pharmacological treatment options are available, with L-dopa being the most effective. Conclusion The symptoms of RLS were 65% resolved in the case presented in one month. Awareness and proper diagnosis by all primary contact practitioners is necessary for effective management of RLS. PMID:18516284

  6. Medication use in patients with restless legs syndrome compared with a control population.

    PubMed

    Pearson, V E; Gamaldo, C E; Allen, R P; Lesage, S; Hening, W A; Earley, C J

    2008-01-01

    Primary restless legs syndrome (RLS) is a sensorimotor disorder causing chronic sleep deprivation in those with moderate to severe symptoms. It has been associated with other medical conditions, such as high blood pressure, depression and attention deficit hyperactive disorder (ADHD). If these conditions are more prevalent for RLS patients, then it would be expected RLS patients would use relatively more of the medications treating these conditions. Current medication use was obtained from 110 RLS patients and 54 age, race and gender-matched local-community controls. Each subject was diagnosed as primary RLS or having no indications for RLS by a clinician board-certified in sleep medicine. The RLS group used more medications than the control group even when medications used for treating RLS were excluded. Significantly more of the RLS patients than controls used anti-depressants, gastro-intestinal (GI) medications and asthma/allergy medications. RLS patients compared with those without RLS are more likely to use medications not related to treating RLS. Moreover they use medications for conditions that have not previously been considered related to RLS, i.e. GI and asthma/allergy conditions.

  7. Iron’s role in paediatric restless legs syndrome – a review

    PubMed Central

    Dosman, Cara; Witmans, Manisha; Zwaigenbaum, Lonnie

    2012-01-01

    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. PMID:23543250

  8. Recent advances in the diagnosis, genetics and treatment of restless legs syndrome.

    PubMed

    Trenkwalder, Claudia; Högl, Birgit; Winkelmann, Juliane

    2009-04-01

    Knowledge of restless legs syndrome (RLS) has greatly increased in recent years due to the many advances that have been made in diagnosis, management and genetics. Tools have been developed that facilitate the diagnosis and treatment of RLS, in particular the essential diagnostic criteria for RLS have been refined, severity scales (IRLS, RLS-6, JHSS) have been developed, as have instruments that improve diagnostic accuracy and assess for specific aspects of RLS such as augmentation. These newly developed tools have been used in recent population-based studies, which have provided a greater understanding of the epidemiology of RLS, and also within patient-based trials. As far as the genetics of RLS is concerned, linkage studies in RLS families have revealed eight loci but no causally related sequence variant has yet been identified using this approach. Recent genome-wide association studies have identified variants within intronic or intergenic regions of MEIS1, BTBD9, and MAP2K5/LBXCOR1, and PTPRD, raising new pathological hypotheses for RLS. An overview on therapeutic options and recent trials is given based on evidence-based management strategies for this common disorder.

  9. Update on the management of restless legs syndrome: existing and emerging treatment options

    PubMed Central

    Facheris, Maurizio F; Hicks, Andrew A; Pramstaller, Peter P; Pichler, Irene

    2010-01-01

    Restless legs syndrome (RLS) is a sensorimotor disorder, characterized by a circadian variation of symptoms involving an urge to move the limbs (usually the legs) as well as paresthesias. There is a primary (familial) and a secondary (acquired) form, which affects a wide variety of individuals, such as pregnant women, patients with end-stage renal disease, iron deficiency, rheumatic disease, and persons taking medications. The symptoms reflect a circadian fluctuation of dopamine in the substantia nigra. RLS patients have lower dopamine and iron levels in the substantia nigra and respond to both dopaminergic therapy and iron administration. Iron, as a cofactor of dopamine production and a regulator of the expression of dopamine type 2-receptor, has an important role in the RLS etiology. In the management of the disease, the first step is to investigate possible secondary causes and their treatment. Dopaminergic agents are considered as the first-line therapy for moderate to severe RLS. If dopaminergic drugs are contraindicated or not efficacious, or if symptoms are resistant and unremitting, gabapentin or other antiepileptic agents, benzodiazepines, or opioids can be used for RLS therapy. Undiagnosed, wrongly diagnosed, and untreated RLS is associated with a significant impairment of the quality of life. PMID:23616710

  10. Nondrug-related aspect of treating Ekbom disease, formerly known as restless legs syndrome.

    PubMed

    Mitchell, Ulrike H

    2011-01-01

    Ekbom disease (EKD), formerly known as restless legs syndrome (RLS) has affected and bothered many people over the centuries. It is one of the most prevalent neurological disorders in Europe and North-America, affecting about 10% of the population. The main characteristics are the strong urge to move, accompanied or caused by uncomfortable, sometimes even distressing, paresthesia of the legs, described as a "creeping, tugging, pulling" feeling. The symptoms often become worse as the day progresses, leading to sleep disturbances or sleep deprivation, which leads to decreased alertness and daytime functions. Numerous studies have been conducted assessing the efficacy of dopaminergic drugs, opioids, and other pharmacologic agents in alleviating EKD symptoms. However, there is also a growing body of evidence demonstrating the effectiveness of nonpharmacologic treatments including life style changes, physical activity programs, pneumatic compression, massage, near-infrared light therapy, and complementary therapies. The working mechanisms behind these alternatives are diverse. Some increase blood flow to the legs, therefore reducing tissue hypoxia; some introduce an afferent counter stimulus to the cortex and with that "close the gate" for aberrant nerve stimulations; some increase dopamine and nitric oxide and therefore augment bio-available neurotransmitters; and some generate endorphins producing an analgesic effect. The advantages of these treatments compared with pharmacologic agents include less or no side effects, no danger of augmentation, and less cost. PMID:21654870

  11. Altered brain iron homeostasis and dopaminergic function in Restless Legs Syndrome (Willis-Ekbom Disease).

    PubMed

    Earley, Christopher J; Connor, James; Garcia-Borreguero, Diego; Jenner, Peter; Winkelman, John; Zee, Phyllis C; Allen, Richard

    2014-11-01

    Restless legs syndrome (RLS), also known as Willis-Ekbom Disease (WED), is a sensorimotor disorder for which the exact pathophysiology remains unclear. Brain iron insufficiency and altered dopaminergic function appear to play important roles in the etiology of the disorder. This concept is based partly on extensive research studies using cerebrospinal fluid (CSF), autopsy material, and brain imaging indicating reduced regional brain iron and on the clinical efficacy of dopamine receptor agonists for alleviating RLS symptoms. Finding causal relations, linking low brain iron to altered dopaminergic function in RLS, has required however the use of animal models. These models have provided insights into how alterations in brain iron homeostasis and dopaminergic system may be involved in RLS. The results of animal models of RLS and biochemical, postmortem, and imaging studies in patients with the disease suggest that disruptions in brain iron trafficking lead to disturbances in striatal dopamine neurotransmission for at least some patients with RLS. This review examines the data supporting an iron deficiency-dopamine metabolic theory of RLS by relating the results from animal model investigations of the influence of brain iron deficiency on dopaminergic systems to data from clinical studies in patients with RLS.

  12. Frequent difficulties in the treatment of restless legs syndrome - case report and literature review.

    PubMed

    Narowska, Dominika; Bożek, Milena; Krysiak, Katarzyna; Antczak, Jakub; Holka-Pokorska, Justyna; Jernajczyk, Wojciech; Wichniak, Adam

    2015-01-01

    Restless legs syndrome (RLS) is one of the most common sleep disorders. The purpose of this paper is a case description of the patient suffering from RLS, concurrent with numerous clinical problems. In our patient, during long-term therapy with a dopamine agonist (ropinirole), the phenomenon of the augmentation, defined as an increase in the severity of the RLS symptoms, was observed. The quality of life of the patient was significantly deteriorated. Due to the augmentation of RLS symptoms the dopaminergic drug was gradually withdrawn, and the gabapentin as a second-line drug for the treatment of RLS was introduced. Because of the large increase of both insomnia and RLS symptoms during the reduction of ropinirole dose, clonazepam was temporarily introduced. In addition, in the neurological assessment of the distal parts of the lower limb sensory disturbances of vibration were found. The neurographic study confirmed axonal neuropathy of the sural nerves, which explained an incomplete response to dopaminergic medications. However, gabapentin treatment in the dose recommended in neuropathies was impossible due to bothersome side effects. Another important issue in the treatment of the patient were depressive symptoms and the fact that the majority of used antidepressants (mirtazapine, mianserin, tricyclic antidepressants) increase the severity of RLS. Among antidepressants recommended for the treatment of depression in patients with RLS (such as bupropion, moclobemide, reboxetine, tianeptine and agomelatine) only agomelatine exhibits promoting sleep properties. Because of the concomitant insomnia, this drug was applied in our patient. PMID:26688843

  13. Heme Oxygenase-1 and 2 Common Genetic Variants and Risk for Restless Legs Syndrome

    PubMed Central

    García-Martín, Elena; Jiménez-Jiménez, Félix Javier; Alonso-Navarro, Hortensia; Martínez, Carmen; Zurdo, Martín; Turpín-Fenoll, Laura; Millán-Pascual, Jorge; Adeva-Bartolomé, Teresa; Cubo, Esther; Navacerrada, Francisco; Rojo-Sebastián, Ana; Rubio, Lluisa; Ortega-Cubero, Sara; Pastor, Pau; Calleja, Marisol; Plaza-Nieto, José Francisco; Pilo-de-la-Fuente, Belén; Arroyo-Solera, Margarita; García-Albea, Esteban; Agúndez, José A.G.

    2015-01-01

    Abstract Several neurochemical, neuropathological, neuroimaging, and experimental data, suggest that iron deficiency plays an important role in the pathophysiology of restless legs syndrome (RLS). Heme-oxygenases (HMOX) are an important defensive mechanism against oxidative stress, mainly through the degradation of heme to biliverdin, free iron, and carbon monoxide. We analyzed whether HMOX1 and HMOX2 genes are related with the risk to develop RLS. We analyzed the distribution of genotypes and allelic frequencies of the HMOX1 rs2071746, HMOX1 rs2071747, HMOX2 rs2270363, and HMOX2 rs1051308 SNPs, as well as the presence of Copy number variations (CNVs) of these genes in 205 subjects RLS and 445 healthy controls. The frequencies of rs2071746TT genotype and rs2071746T allelic variant were significantly lower in RLS patients than that in controls, although the other 3 studied SNPs did not differ between RLS patients and controls. None of the studied polymorphisms influenced the disease onset, severity of RLS, family history of RLS, serum ferritin levels, or response to dopaminergic agonist, clonazepam or GABAergic drugs. The present study suggests a weak association between HMOX1 rs2071746 polymorphism and the risk to develop RLS in the Spanish population. PMID:26313808

  14. Does Pramipexole Treatment Improve Headache in Patients with Concomitant Migraine and Restless Legs Syndrome?

    PubMed Central

    Suzuki, Keisuke; Suzuki, Shiho; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Numao, Ayaka; Watanabe, Yuka; Takashima, Ryotaro; Hirata, Koichi

    2013-01-01

    Background Recent studies have suggested a strong link between migraines and restless legs syndrome (RLS). It is possible that these disorders share a dopaminergic dysfunction in the hypothalamic A11 nucleus that contributes to this association. However, there have been no clinical studies to evaluate the effect of dopaminergic treatment on migraine symptoms in patients with concomitant migraines and RLS. Methods We present an illustrative patient with concomitant RLS and migraine who showed improvement in her headache frequency and RLS symptoms following immediate-release pramipexole (P-IR) treatment and provide review results from the medical records of patients who experienced both migraines and RLS in our previous cross-sectional study. Results Ten patients (nine patients from the previously completed single-center study) received P-IR treatment were included in the study. RLS symptoms improved markedly in all of the subjects. Five out of the 10 patients (50%) reported improvement in migraine headaches. Of these five patients, four (80%) had reported morning headaches before P-IR treatment. Discussion Our results indicate that the identification of RLS in migraine patients is clinically significant and that dopaminergic treatment may improve both migraines, particularly morning headache (80% improvement in this study), and RLS symptoms. However, further clinical studies are warranted to verify our results. PMID:24116342

  15. Advances in pediatric restless legs syndrome: Iron, genetics, diagnosis and treatment.

    PubMed

    Picchietti, Matthew A; Picchietti, Daniel L

    2010-08-01

    A substantial literature characterizes pediatric restless legs syndrome (RLS), which occurs in about 1.9% of individuals between 8 and 18years of age. Diagnostic interview techniques and an updated inventory of pediatric RLS mimics are presented. Evidence for comorbidity of pediatric RLS with attention-deficit/hyperactivity disorder, depression, and anxiety is reviewed as is the relationship to periodic limb movements in sleep and periodic limb movement disorder. The role of relative iron deficiency in pediatric RLS is discussed, along with new data indicating the benefit of iron therapy in reducing symptoms. Five genetic variants have been linked to RLS, an important finding in a condition that is highly familial in early-onset cases. Numerous case reports and case series indicate benefit for moderate to severe pediatric RLS with medication. However, to date, there have been no double-blind, placebo-controlled studies of therapy for pediatric RLS published. These and other recent advances relevant to pediatric RLS research are reviewed. PMID:20620105

  16. Size and accumulation of fuel reserves at stopover predict nocturnal restlessness in a migratory bird

    PubMed Central

    Eikenaar, Cas; Schläfke, Jan Laszlo

    2013-01-01

    Early arrival at the breeding site positively affects the breeding success of migratory birds. During migration, birds spend most of their time at stopovers. Therefore, determining which factors shape stopover duration is essential to our understanding of avian migration. Because the main purpose of stopover is to accumulate fat as fuel for the next flight bout, fuel reserves at arrival and the accumulation of fuel are both expected to affect stopover departure decisions. Here, we determined whether fuel reserves and fuel accumulation predict a bird's motivation to depart, as quantified by nocturnal migratory restlessness (Zugunruhe), using northern wheatears (Oenanthe oenanthe) that were captured and temporarily contained at spring stopover. We found that fuel reserves at capture were positively correlated with Zugunruhe, and negatively correlated with fuel accumulation. This indicates that fat birds were motivated to depart, whereas lean birds were set on staying and accumulating fuel. Moreover, the change in fuel reserves was positively correlated with the concurrent change in Zugunruhe, providing the first empirical evidence for a direct link between fuel accumulation and Zugunruhe during stopover. Our study indicates that, together with innate rhythms and weather, the size and accumulation of fuel reserves shape stopover duration, and hence overall migration time. PMID:24132097

  17. Highly Potent Extracts from Pea (Pisum sativum) and Maize (Zea mays) Roots Can Be Used to Induce Quiescence in Entomopathogenic Nematodes.

    PubMed

    Jaffuel, Geoffrey; Hiltpold, Ivan; Turlings, Ted C J

    2015-09-01

    Root exudates can play an important role in plant-nematode interactions. Recent studies have shown that the root cap exudates obtained from several plant species trigger a state of dormancy or quiescence in various genera of nematodes. This phenomenon is not only of fundamental ecological interest, but also has application potential if the plant-produced compound(s) could be used to control harmful nematodes or help to prolong the shelf-life of beneficial entomopathogenic nematodes (EPNs). The identification of the compound(s) involved in quiescence induction has proven to be a major challenge and requires large amounts of active material. Here, we present a high-throughput method to obtain bioactive root extracts from flash-frozen root caps of green pea and maize. The root cap extract obtained via this method was considerably more potent in inducing quiescence than exudate obtained by a previously used method, and consistently induced quiescence in the EPN Heterorhabditis megidis, even after a 30-fold dilution. Extracts obtained from the rest of the root were equally effective in inducing quiescence. Infective juveniles (IJs) of H. megidis exposed to these extracts readily recovered from their quiescent state as soon as they were placed in moist soil, and they were at least as infectious as the IJs that had been stored in water. Excessive exposure of IJs to air interfered with the triggering of quiescence. The implications of these results and the next steps towards identification of the quiescence-inducing compound(s) are discussed from the perspective of applying EPN against soil-dwelling insect pests. PMID:26364294

  18. Highly Potent Extracts from Pea (Pisum sativum) and Maize (Zea mays) Roots Can Be Used to Induce Quiescence in Entomopathogenic Nematodes.

    PubMed

    Jaffuel, Geoffrey; Hiltpold, Ivan; Turlings, Ted C J

    2015-09-01

    Root exudates can play an important role in plant-nematode interactions. Recent studies have shown that the root cap exudates obtained from several plant species trigger a state of dormancy or quiescence in various genera of nematodes. This phenomenon is not only of fundamental ecological interest, but also has application potential if the plant-produced compound(s) could be used to control harmful nematodes or help to prolong the shelf-life of beneficial entomopathogenic nematodes (EPNs). The identification of the compound(s) involved in quiescence induction has proven to be a major challenge and requires large amounts of active material. Here, we present a high-throughput method to obtain bioactive root extracts from flash-frozen root caps of green pea and maize. The root cap extract obtained via this method was considerably more potent in inducing quiescence than exudate obtained by a previously used method, and consistently induced quiescence in the EPN Heterorhabditis megidis, even after a 30-fold dilution. Extracts obtained from the rest of the root were equally effective in inducing quiescence. Infective juveniles (IJs) of H. megidis exposed to these extracts readily recovered from their quiescent state as soon as they were placed in moist soil, and they were at least as infectious as the IJs that had been stored in water. Excessive exposure of IJs to air interfered with the triggering of quiescence. The implications of these results and the next steps towards identification of the quiescence-inducing compound(s) are discussed from the perspective of applying EPN against soil-dwelling insect pests.

  19. X-ray and Optical Studies of SAX J1808.4-3658 in Quiescence

    NASA Astrophysics Data System (ADS)

    Heinke, C. O.; Deloye, C. J.; Jonker, P. G.; Wijnands, R.; Taam, R. E.

    2008-10-01

    We have observed the accreting millisecond X-ray pulsar SAX J1808.4-3658 (1808) in quiescence during two 50 ksec XMM-Newton observations, and acquired near-simultaneous photometry with Gemini South. We find 1808's X-ray spectrum to be hard, describable with an absorbed power-law of photon index 1.7-1.9 and unabsorbed X-ray luminosity Lx = 5.2-7.9×1031 ergs s-1. No thermal neutron star (NS) component is seen, with a limit on any possible NS component of LNS(0.01-10 keV)<6.2×1030 ergs s-1. (However, an alternative thermal plasma continuum model for 1808 allows a NS component with up to LNS(0.01-10 keV) = 1.3-0.8+0.6×1031 ergs/s.) This constraint, combined with 1808's accretion history, requires highly enhanced neutrino cooling in the core of 1808's NS. The near-simultaneous Gemini observations find a large sinusoidal flux modulation on 1808's orbital period, consistent with predictions from an irradiated secondary star. We model the contributions of the disk and donor star, and find that the donor must be irradiated by an external flux of Lirr = 1.15-1.78×1034 ergs/s, much larger than observed in the X-ray band. This irradiation may be in the form of relativistic particles from the NS turning on as a radio pulsar when not accreting, as suggested by Burderi et al. The amplitude and color dependence of the optical modulation constrain the system inclination and donor radius. These constraints, through the pulsar mass function, deliver constraints on the NS mass of MNS>2.2 Msolar, or for a distance uncertainty 10% larger, of MNS>1.8 Msolar. Such a heavy NS is consistent with the accelerated neutrino cooling found from the X-ray observations.

  20. Adenovirus type 5 exerts genome-wide control over cellular programs governing proliferation, quiescence, and survival

    PubMed Central

    Miller, Daniel L; Myers, Chad L; Rickards, Brenden; Coller, Hilary A; Flint, S Jane

    2007-01-01

    Background Human adenoviruses, such as serotype 5 (Ad5), encode several proteins that can perturb cellular mechanisms that regulate cell cycle progression and apoptosis, as well as those that mediate mRNA production and translation. However, a global view of the effects of Ad5 infection on such programs in normal human cells is not available, despite widespread efforts to develop adenoviruses for therapeutic applications. Results We used two-color hybridization and oligonucleotide microarrays to monitor changes in cellular RNA concentrations as a function of time after Ad5 infection of quiescent, normal human fibroblasts. We observed that the expression of some 2,000 genes, about 10% of those examined, increased or decreased by a factor of two or greater following Ad5 infection, but were not altered in mock-infected cells. Consensus k-means clustering established that the temporal patterns of these changes were unexpectedly complex. Gene Ontology terms associated with cell proliferation were significantly over-represented in several clusters. The results of comparative analyses demonstrate that Ad5 infection induces reversal of the quiescence program and recapitulation of the core serum response, and that only a small subset of the observed changes in cellular gene expression can be ascribed to well characterized functions of the viral E1A and E1B proteins. Conclusion These findings establish that the impact of adenovirus infection on host cell programs is far greater than appreciated hitherto. Furthermore, they provide a new framework for investigating the molecular functions of viral early proteins and information relevant to the design of conditionally replicating adenoviral vectors. PMID:17430596

  1. Ionization and electric field properties of auroral arcs during magnetic quiescence

    SciTech Connect

    Robinson, R.M.; Mende, S.B. )

    1990-12-01

    Studies of the morphology of auroral precipitation during times of magnetic quiescence indicate that the polar cap shrinks and becomes distorted into a teardrop or pear-shaped region. On November 16, 1987, incoherent scatter radar and all-sky imaging photometer measurements were made of auroral arcs over Sondre Stromfjord, Greenland. The arcs were generally oriented in a geographic east-west direction which is approximately Sun aligned at a local time just after dusk. Kp was 1, and the interlplanetary magnetic field was northward during the time of observation, so tha the arcs occurred under magnetically quiet conditions. The Sondrestrom radar measurements were used to determine the electron density and plasma drifts associated with the arcs; the all-sky imaging photometer data were used to relate the radar measurements to the arc morphology. Assuming the arcs were produced by precipitating electrons, the height profiles of electron density indicate average energies less than about 2 keV and energy fluxes of 1 erg/(cm{sup 2}s). F region electron densities were high in the polar cap north of the arcs and low within the region of the arcs. The poleward boundary of the arc system was a convection reversal boundary across which plasma exited the polar cap region moving antisunward and then turned sunward (westward). The observed arc-associated convection is consistent with that expected under these geomagnetic conditions. Comparison of these results with the electrodynamic properties of other arcs observed in the afternoon and early evening suggests that there is a system of arcs that delineates the afternoon convection cell. The observed gradient in F region electron density across the arc can be explained in terms of the recombination of ionization drifting in response to the arc-associated convection pattern.

  2. Short day-triggered quiescence promotes water conservation in the American dog tick, Dermacentor variabilis.

    PubMed

    Yoder, Jay A; Rosendale, Andrew J; Benoit, Joshua B

    2016-04-01

    A short day-long day exposure comparison of water balance characteristics throughout the life history of the American dog tick, Dermacentor variabilis, was conducted to examine how this tick survives winter-associated dryness. Larvae, nymphs, and adults under potential diapause-inducing conditions (short day, 20 °C) have low water loss rates compared to long day exposed ticks. Above the critical equilibrium activity, these nonfed ticks show greater water gain from lower water vapor activities. In contrast to nonfed stages, eggs and blood-engorged stages (fed larva, fed nymph) were enhanced for water conservation independent of short day exposure and did not display reduced water loss rates under short day conditions. This short day-prompted response in nonfed ticks was distinguished from a genetically programmed diapause as noted in other arthropods by: (1) reduction in water loss was temporary and could be reversed quickly by transferring to long day for only a single day, then re-triggered by returning to short day conditions; (2) switch between low and high water loss rates could be induced multiple times and for multiple different stages; and (3) response by ticks was to the photoperiod they were under, not the condition that was experienced by previous fed stages or in the mother in the case of eggs. Furthermore, short day had no impact on altering body water content, dehydration tolerance limit, instar yields, or developmental stadia. We conclude that a short day-triggered quiescence reduces desiccation stress associated with overwintering in nonfed ticks. This effect on water conservation due to short day exposure is more pronounced for subadults and is likely due to their increased sensitivity to water loss as a result of their smaller size, which is critical to prevent dehydration during the dry winter periods.

  3. 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.

  4. 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.

  5. 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.

  6. 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

    2015-03-01

    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. PMID:25745168

  7. 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.

  8. 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

    2015-03-01

    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.

  9. 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.

  10. A low-level activation technique for monitoring thermonuclear fusion plasma conditions.

    PubMed

    Gasparro, Joël; Hult, Mikael; Bonheure, Georges; Johnston, Peter N

    2006-01-01

    Optimisation of the confinement and sustainability of a thermonuclear plasma requires methods to monitor processes in the plasma. In this work three materials were used as activation targets (Ti, MgF2 and a TiVAl compound). They were placed inside the joint European Torus (JET) vacuum chamber. Certain gamma-ray emitting radionuclides (7Be, 54Mn, 56Co, 57Co, 58Co and 46Sc) were measured using ultra low-level gamma-ray spectrometry in an underground laboratory 1-2 months after activation. They were found to arise from neutron activation of bulk sample material and surface contaminants sputtered from other Tokamak parts. Decision thresholds for some activation products were determined in order to aid in giving upper bounds for the flux of charged particles.

  11. Temperature measurement during thermonuclear X-ray bursts with BeppoSAX

    NASA Astrophysics Data System (ADS)

    Beri, Aru; Paul, Biswajit; Orlandini, Mauro; Maitra, Chandreyee

    2016-05-01

    We have carried out a study of temperature evolution during thermonuclear bursts in LMXBs using broad band data from two instruments onboard BeppoSAX, the MECSand the PDS. However, instead of applying the standard technique of time resolved spectroscopy, we have determined the temperature in small time intervals using the ratio of count rates in the two instruments assuming a blackbody nature of burst emission and different interstellar absorption for different sources. Data from a total of twelve observations of six sources were analyzed during which 22 bursts were detected. We have obtained temperatures as high as ˜3.0 keV, even when there is no evidence of photospheric radius expansion. These high temperatures were observed in the sources within different broadband spectral states (soft and hard).

  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. 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.

  14. 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.

  15. 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.

  16. 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.

  17. The effect of relativistic Compton scattering on thermonuclear burn of pure deuterium fuel

    NASA Astrophysics Data System (ADS)

    Ghasemizad, A.; Nazirzadeh, M.; Khanbabaei, B.

    2016-08-01

    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.

  18. Regulation of human ornithine decarboxylase expression following prolonged quiescence: role for the c-Myc/Max protein complex.

    PubMed

    Peña, A; Wu, S; Hickok, N J; Soprano, D R; Soprano, K J

    1995-02-01

    WI-38 cells can remain quiescent for long periods of time and still be induced to reenter the cell cycle by the addition of fresh serum. However, the longer these cells remain growth arrested, the more time they require to enter S phase. This prolongation of the prereplicative phase has been localized to a point early in G1, after the induction of "immediate early" G1 genes such as c-fos and c-jun but before maximal expression of "early" G1 genes such as ornithine decarboxylase (ODC). Understanding the molecular basis for ODC mRNA induction can therefore provide information about the molecular events which regulate the progression of cells out of long-term quiescence into G1 and subsequently into DNA synthesis. Studies utilizing electrophoretic mobility shift assays (EMSA) of nuclear extracts from short- and long-term quiescent WI-38 cells identified a region of the human ODC promoter at -491 bp to -474 bp which exhibited a protein binding pattern that correlated with the temporal pattern of ODC mRNA expression. The presence of a CACGTG element within this fragment, studies with antibodies against c-Myc and Max, the use of purified recombinant c-Myc protein in the mobility shift assay, and antisense studies suggest that these proteins can specifically bind this portion of the human ODC promoter in a manner consistent with growth-associated modulation of the expression of ODC and other early G1 genes following prolonged quiescence. These studies suggest a role for the c-Myc/Max protein complex in regulating events involved in the progression of cells out of long-term quiescence into G1 and subsequently into S.

  19. Observations of the X-ray Nova GRO J0422+32. 1: Outburst and the decay to quiescence

    NASA Technical Reports Server (NTRS)

    Callanan, Paul J.; Garcia, Michael R.; Mcclintock, Jeffrey E.; Zhao, Ping; Remillard, Ronald A.; Bailyn, Charles D.; Orosz, Jerome A.; Harmon, B. Alan; Paciesas, William S.

    1995-01-01

    We present optical photometry and spectroscopy and Burst and Transient Source Experiment (BATSE) observations of the X-ray nova GRO J0422+32, obtained during outburst and its subsequent decay to quiescence. Although the X-ray and optical properties of GRO J0422+32 are broadly similar to those of other X-ray novae, it is unique in several respects. The unusually protracted decay to quiescence of the optical light curve has been punctuated by at least two minioutbursts of approximately 4 mag. The BATSE and optical outbursts are each separated by approximately 120 days. We find that the optical luminosity of GRO J0422+32 during the primary outburst is dominated by reprocessing of E greater than 10 keV X-rays. In contrast, the optical minioutbursts are most likely generated by an intrinsically bright disk rather than X-ray reprocessing: they do not appear to have any X-ray counterparts. Extremely broad (up to 6000 km/s FWZI) absorption lines have also been observed during both primary outbursts and minioutbursts. During the second minioutburst, H-alpha and H-beta emission was observed superposed on redshifted absorption features. We find that the interoutburst light curve of GRO J0422+32 may be inconsistent with an accretion disk instability as the origin of the minioutbursts. Finally, a transient 5.1/10.2 hr modulation, which may be related to the orbital period, has been observed during roughly half of our observations. However, confirmation of the orbital period must await observations in quiescence.

  20. 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.

  1. 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.

  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. 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.

  4. The HEAO-A2 soft X-ray survey of cataclysmic variable stars - EX Hydrae during optical quiescence

    NASA Technical Reports Server (NTRS)

    Cordova, F. A.; Riegler, G. R.

    1979-01-01

    Results are reported for HEAO A2 soft X-ray (below 2 keV) scanning observations of the southern dwarf nova EX Hya. An X-ray light curve is presented which shows no apparent orbital modulation. The best-fitting spectral parameters are derived for the source, and the observations are compared with the spectral behavior of the dwarf nova SS Cyg during optical quiescence. The results are discussed in terms of models for X-ray production by accreting white dwarfs.

  5. [Effect of high dose pergolide mesilate on restless legs syndrome associated with Parkinson disease].

    PubMed

    Imamura, Akiko; Tsuboi, Yoshio; Tanaka, Miki; Obata, Toyoshi; Yamada, Tatsuo

    2007-04-01

    Restless legs syndrome (RLS) is one of the common nocturnal disturbance seen in Parkinson's disease (PD) patients. The prevalence of RLS with PD is greater than that of general populations; however, etiology of RLS in patients with PD is still controversial. We report a 63-year-old man with PD, who was admitted to our hospital with uncontrollable unpleasant feeling in both legs leading to sleep disturbance. At age 59, he experienced numbness and nocturnal myoclonus in his right foot. One year later, he developed resting tremor and bradykinesia in his right hand, and was diagnosed as PD. Levodopa was initiated with favorable response for his resting tremor and bradykinesia, however, his dysesthesia of the legs spread to both side and associated with an urge to move which occurs at rest and was ameliorated by walking. On admission, his parkinsonism was well controlled by 400 mg/ day of levodopa/benserazide. Polysomnography (PSG) revealed periodic limb movements in sleep (PLMS). Secondary RLS such as drug-induced, iron deficiency and uraemia, was excluded in this patient. Because levodopa did not improve his RLS, additional symptomatic RLS treatment was initiated. Oral dosage with 150 microg pergolide did not have any effect on his RLS symptoms. An increase up to 750 microg pergolide led to a marked reduction of symptoms. Repeated PSG showed significant reduction of PLMS and improved sleep efficacy. Usually, low dose of dopamine agonist is enough to treat RLS occurred in general populations. However, moderate to high dose of dopamine agonists were needed for our patient with RLS, indicating that pharmacological responses might be different between RLS in general and that associated with PD. It is important to consider that PD-related RLS can be treated with high dose dopamine agonist to obtain favorable management of nocturnal disturbances. PMID:17511286

  6. Intractable restless legs syndrome: role of prolonged-release oxycodone-naloxone.

    PubMed

    de Biase, Stefano; Valente, Mariarosaria; Gigli, Gian Luigi

    2016-01-01

    Restless legs syndrome (RLS) is a common neurological disorder characterized by an irresistible urge to move the legs accompanied by uncomfortable sensations that occur at night or at time of rest. Pharmacological therapy should be limited to patients who suffer from clinically relevant symptoms. Chronic RLS is usually treated with either a dopamine agonist (pramipexole, ropinirole, rotigotine) or an α2δ calcium-channel ligand (gabapentin, gabapentin enacarbil, pregabalin). Augmentation is the main complication of long-term dopaminergic treatment, and frequently requires a reduction of current dopaminergic dose or a switch to non-dopaminergic medications. Opioids as monotherapy or add-on treatment should be considered when alternative satisfactory regimens are unavailable and the severity of symptoms warrants it. In a recent Phase III trial, oxycodone-naloxone prolonged release (PR) demonstrated a significant and sustained effect on patients with severe RLS inadequately controlled by previous treatments. The adverse-event profile was consistent with the safety profile of opioids. The most frequent adverse events were fatigue, constipation, nausea, headache, hyperhidrosis, somnolence, dry mouth, and pruritus. Adverse events were usually mild or moderate in intensity. No cases of augmentation were reported. Oxycodone-naloxone PR is approved for the second-line symptomatic treatment of adults with severe to very severe idiopathic RLS after failure of dopaminergic treatment. Further studies are needed to evaluate if oxycodone-naloxone PR is equally efficacious as a first-line treatment. Moreover, long-term comparative studies between opioids, dopaminergic drugs and α2δ ligands are needed. PMID:26966363

  7. Intractable restless legs syndrome: role of prolonged-release oxycodone–naloxone

    PubMed Central

    de Biase, Stefano; Valente, Mariarosaria; Gigli, Gian Luigi

    2016-01-01

    Restless legs syndrome (RLS) is a common neurological disorder characterized by an irresistible urge to move the legs accompanied by uncomfortable sensations that occur at night or at time of rest. Pharmacological therapy should be limited to patients who suffer from clinically relevant symptoms. Chronic RLS is usually treated with either a dopamine agonist (pramipexole, ropinirole, rotigotine) or an α2δ calcium-channel ligand (gabapentin, gabapentin enacarbil, pregabalin). Augmentation is the main complication of long-term dopaminergic treatment, and frequently requires a reduction of current dopaminergic dose or a switch to non-dopaminergic medications. Opioids as monotherapy or add-on treatment should be considered when alternative satisfactory regimens are unavailable and the severity of symptoms warrants it. In a recent Phase III trial, oxycodone–naloxone prolonged release (PR) demonstrated a significant and sustained effect on patients with severe RLS inadequately controlled by previous treatments. The adverse-event profile was consistent with the safety profile of opioids. The most frequent adverse events were fatigue, constipation, nausea, headache, hyperhidrosis, somnolence, dry mouth, and pruritus. Adverse events were usually mild or moderate in intensity. No cases of augmentation were reported. Oxycodone–naloxone PR is approved for the second-line symptomatic treatment of adults with severe to very severe idiopathic RLS after failure of dopaminergic treatment. Further studies are needed to evaluate if oxycodone–naloxone PR is equally efficacious as a first-line treatment. Moreover, long-term comparative studies between opioids, dopaminergic drugs and α2δ ligands are needed. PMID:26966363

  8. Is nocturnal eating in restless legs syndrome linked to a specific psychopathological profile? A pilot study.

    PubMed

    Marconi, Sara; Scarlatti, Fabiano; Rizzo, Giovanni; Antelmi, Elena; Innamorati, Marco; Pompili, Maurizio; Brugnoli, Roberto; Belvederi Murri, Martino; Amore, Mario; Provini, Federica

    2015-11-01

    The purpose of the study was to evaluate psychological comorbidity in drug-naive or drug-free primary restless legs syndrome (p-RLS) patients with nocturnal eating disorder (NED), and to analyze the association of comorbid p-RLS and NED with obsessive-compulsive, mood and anxiety symptoms, and personality. Participants comprised 20 consecutive female outpatients with p-RLS, 10 without NED and 10 with NED, and 10 female controls matched for age. Both patients and controls were evaluated by the Hamilton Depression and the Anxiety Rating Scales, the State-Trait Anxiety Inventory, the Maudsley Obsessive Compulsive Inventory and the temperament and character inventory-revised. Compared to controls, p-RLS patients without and with NED had higher trait anxiety and current anxiety and obsessive-compulsive symptoms. p-RLS patients with NED also had significantly higher doubting compared to p-RLS patients without NED. Furthermore, groups differed for harm avoidance (HA), with p-RLS patients with and without NED having higher scores than controls. Untreated p-RLS patients, particularly those with nocturnal eating, report anxiety and obsessive-compulsive symptoms, perceive stressful situations as dangerous and threatening and tend to respond with anxiety to such situations. They have higher tendency to respond intensely to aversive stimuli, inhibiting behavior to avoid punishment, novelty, and frustrative omission of expected rewards. We hypothesize that higher levels of HA, a biologically determined personality trait, might constitute a diathesis predisposing individuals to display obsessive-compulsive symptoms, namely increasingly severe compulsive nocturnal eating. PMID:26233564

  9. Relationships Between Malnutrition, Inflammation, Sleep Quality, and Restless Legs Syndrome in Hemodialysis Patients.

    PubMed

    Kaya, Tezcan; Acar, Bilgehan Atılgan; Sipahi, Savaş; Cinemre, Hakan; Acar, Türkan; Varım, Ceyhun; Tamer, Ali

    2015-10-01

    Restless legs syndrome (RLS) is a common neurologic sensorimotor disorder. It is also seen in hemodialysis patients in whom the mechanism is not thoroughly understood. The aim of this study was to evaluate the association between malnutrition-inflammation score (MIS), sleep quality, and RLS in chronic hemodialysis patients. This cross-sectional study included 232 adult stable chronic hemodialysis patients (mean age 60.9 ± 14.1 years, 56.5% male). RLS frequency, MIS, Pittsburgh Sleep Quality Index (PSQI), laboratory data of patients as well as severity of RLS were evaluated. Thirty-seven patients (15.9%) were diagnosed with RLS. Mean MIS of patients with or without RLS were similar. PSQI of patients with RLS was significantly higher than patients without RLS (P = 0.002). There was a significant positive correlation between RLS severity and PSQI (r = 0.445, P = 0.006). A significant positive correlation was also found between PSQI and MIS in patients with RLS (r = 0.419, P = 0.010). RLS severity was positively correlated with some inflammatory parameters such as white blood cell count and C-reactive protein (r = 0.427, P = 0.008 and r = 0.418 P = 0.010). PSQI was found as an independent significant predictor of RLS (odds ratio [OR] = 1.15 (1.06-1.25), P = 0.001) in multivariate logistic regression analysis. Our study revealed that there was no significant relationship between RLS and MIS in chronic hemodialysis patients. However, RLS severity is correlated with inflammatory parameters. Also, sleep quality in chronic hemodialysis patients with RLS is negatively associated with MIS. PMID:26031339

  10. Prospective study of obesity, hypertension, high cholesterol, and risk of restless legs syndrome.

    PubMed

    De Vito, Katerina; Li, Yanping; Batool-Anwar, Salma; Ning, Yi; Han, Jiali; Gao, Xiang

    2014-07-01

    Because previous cross-sectional studies suggest an association between metabolic disorders and restless legs syndrome (RLS), we prospectively evaluated whether obesity, hypercholesterolemia, and hypertension were associated with increased risk of RLS. Our study consisted of 42,728 female participants from the Nurses' Health Study II and 12,812 male participants from the Health Professionals Follow-up Study, free of RLS at baseline (2002 for men and 2005 for women), and free of diabetes and arthritis through follow-up (2002-2008 for men and 2005-2009 for women). RLS symptoms were assessed using the International RLS Study Group's standardized questionnaire. We considered RLS symptoms a "case" if the symptoms occurred ≥5 times/month and met International RLS Study Group criteria. We found that obesity was associated with an increased risk RLS among both men and women (P difference for sex >0.5). The pooled multivariate-adjusted odds ratio (OR) for RLS was 1.57 (95% confidence interval [CI]: 1.33-1.85; P trend <0.0001) for body mass index >30 versus ≤23 kg/m(2) and 1.56 (95% CI: 1.29-1.89; P trend = 0.0001) comparing two extreme waist circumference quintiles, adjusting for age, ethnicity, smoking, physical activity, use of antidepressant, and other covariates. A similar significant association was found for high cholesterol; the pooled adjusted OR for total serum cholesterol >240 versus <159 mg/dL was 1.33 (95% CI: 1.11-1.60; P trend = 0.002). There was no significant association between hypertension and RLS risk (adjusted OR: 0.90; 95% CI: 0.79-1.02). In this large, prospective study, we found that obesity and high cholesterol, but not high blood pressure, were significantly associated with an increased risk of developing RLS. © 2014 International Parkinson and Movement Disorder Society.

  11. Relationships Between Malnutrition, Inflammation, Sleep Quality, and Restless Legs Syndrome in Hemodialysis Patients.

    PubMed

    Kaya, Tezcan; Acar, Bilgehan Atılgan; Sipahi, Savaş; Cinemre, Hakan; Acar, Türkan; Varım, Ceyhun; Tamer, Ali

    2015-10-01

    Restless legs syndrome (RLS) is a common neurologic sensorimotor disorder. It is also seen in hemodialysis patients in whom the mechanism is not thoroughly understood. The aim of this study was to evaluate the association between malnutrition-inflammation score (MIS), sleep quality, and RLS in chronic hemodialysis patients. This cross-sectional study included 232 adult stable chronic hemodialysis patients (mean age 60.9 ± 14.1 years, 56.5% male). RLS frequency, MIS, Pittsburgh Sleep Quality Index (PSQI), laboratory data of patients as well as severity of RLS were evaluated. Thirty-seven patients (15.9%) were diagnosed with RLS. Mean MIS of patients with or without RLS were similar. PSQI of patients with RLS was significantly higher than patients without RLS (P = 0.002). There was a significant positive correlation between RLS severity and PSQI (r = 0.445, P = 0.006). A significant positive correlation was also found between PSQI and MIS in patients with RLS (r = 0.419, P = 0.010). RLS severity was positively correlated with some inflammatory parameters such as white blood cell count and C-reactive protein (r = 0.427, P = 0.008 and r = 0.418 P = 0.010). PSQI was found as an independent significant predictor of RLS (odds ratio [OR] = 1.15 (1.06-1.25), P = 0.001) in multivariate logistic regression analysis. Our study revealed that there was no significant relationship between RLS and MIS in chronic hemodialysis patients. However, RLS severity is correlated with inflammatory parameters. Also, sleep quality in chronic hemodialysis patients with RLS is negatively associated with MIS.

  12. A Further Drop into Quiescence by the Eclipsing Neutron Star 4U 2129+47

    NASA Astrophysics Data System (ADS)

    Lin, Jinrong; Nowak, Michael A.; Chakrabarty, Deepto

    2009-09-01

    A Further Drop into Quiescence by the Eclipsing Neutron Star 4U 2129+47 Abstract: The low mass X-ray binary 4U 2129+47 was discovered during a previous X-ray outburst phase and was classified as an accretion disk corona source due to its broad and partial X-ray eclipses occurring periodically on a 5.24 hr orbit. The source entered a X-ray quiescent state in 1983 wherein its optical modulation disappeared and an F8 IV star--- rather than an expected late K or M star--- was revealed. This suggested that 4U 2129+47 might be in a hierarchical triple system. A 1% delay between two mid-eclipse epochs measured ˜22 days apart was reported from two XMM-Newton observations taken in 2005, providing further support in favor of the triple nature of 4U 2129+47. Compared to a year 2000 Chandra observation, the XMM-Newton observations lacked sinusoidal orbital modulation in the light curve, and only upper limits (roughly consistent with the detection in the Chandra observation) could be placed on the presence of a powerlaw hard tail. In this work we present timing and spectral analysis of three recent XMM-Newton observations of 4U 2129+47, carried out between November 2007 and January 2008. We found that absent the two 2005 XMM-Newton observations, all other observations are consistent with a linear ephemeris with a constant period of 18857.63 s; however, we confirm the time delay reported for the two 2005 XMM-Newton observations. These new observations also confirm the disappearance of the sinusoidal modulation of the lightcurve. We further show that compared to the year 2000 it Chandra observations, all of the XMM-Newton observations have 40% lower 0.5 - 2 keV fluxes, and the most recent XMM-Newton observations have a combined 2--6 keV flux that is nearly 80% lower. Taken as a whole, the timing results support the hypothesis that the system is in a hierarchical triple system (with a third body period of at least 175 days). The spectral results raise the question of whether the

  13. Quantifying Limits on Replication, Death, and Quiescence of Mycobacterium tuberculosis in Mice

    PubMed Central

    McDaniel, Margaret M.; Krishna, Nitin; Handagama, Winode G.; Eda, Shigetoshi; Ganusov, Vitaly V.

    2016-01-01

    When an individual is exposed to Mycobacterium tuberculosis (Mtb) three outcomes are possible: bacterial clearance, active disease, or latent infection. It is generally believed that most individuals exposed to Mtb become latently infected and carry the mycobacteria for life. How Mtb is maintained during this latent infection remains largely unknown. During an Mtb infection in mice, there is a phase of rapid increase in bacterial numbers in the murine lungs within the first 3 weeks, and then bacterial numbers either stabilize or increase slowly over the period of many months. It has been debated whether the relatively constant numbers of bacteria in the chronic infection result from latent (dormant, quiescent), non-replicating bacteria, or whether the observed Mtb cell numbers are due to balance between rapid replication and death. A recent study of mice, infected with a Mtb strain carrying an unstable plasmid, showed that during the chronic phase, Mtb was replicating at significant rates. Using experimental data from this study and mathematical modeling we investigated the limits of the rates of bacterial replication, death, and quiescence during Mtb infection of mice. First, we found that to explain the data the rates of bacterial replication and death could not be constant and had to decrease with time since infection unless there were large changes in plasmid segregation probability over time. While a decrease in the rate of Mtb replication with time since infection was expected due to depletion of host's resources, a decrease in the Mtb death rate was counterintuitive since Mtb-specific immune response, appearing in the lungs 3–4 weeks after infection, should increase removal of bacteria. Interestingly, we found no significant correlation between estimated rates of Mtb replication and death suggesting the decline in these rates was driven by independent mechanisms. Second, we found that the data could not be explained by assuming that bacteria do not die

  14. Accretion dynamics of EX Lupi in quiescence. The star, the spot, and the accretion column

    NASA Astrophysics Data System (ADS)

    Sicilia-Aguilar, Aurora; Fang, Min; Roccatagliata, Veronica; Collier Cameron, Andrew; Kóspál, Ágnes; Henning, Thomas; Ábrahám, Peter; Sipos, Nikoletta

    2015-08-01

    Context. EX Lupi is a young, accreting M0 star and the prototype of EXor variable stars. Its spectrum is very rich in emission lines, including many metallic lines with narrow and broad components. The presence of a close companion has also been proposed, based on radial velocity signatures. Aims: We use the metallic emission lines to study the accretion structures and to test the companion hypothesis. Methods: We analyse 54 spectra obtained during five years of quiescence time. We study the line profile variability and the radial velocity of the narrow and broad metallic emission lines. We use the velocity signatures of different species with various excitation conditions and their time dependency to track the dynamics associated with accretion. Results: We observe periodic velocity variations in the broad and the narrow line components, consistent with rotational modulation. The modulation is stronger for lines with higher excitation potentials (e.g. He II), which are likely produced in a confined area very close to the accretion shock. Conclusions: We propose that the narrow line components are produced in the post-shock region, while the broad components originate in the more extended, pre-shock material in the accretion column. All the emission lines suffer velocity modulation due to the rotation of the star. The broad components are responsible for the line-dependent veiling observed in EX Lupi. We demonstrate that a rotationally modulated line-dependent veiling can explain the radial velocity signature of the photospheric absorption lines, making the close-in companion hypothesis unnecessary. The accretion structure is locked to the star and very stable during the five years of observations. Not all stars with similar spectral types and accretion rates show the same metallic emission lines, which could be related to differences in temperature and density in their accretion structure(s). The contamination of photospheric signatures by accretion

  15. Quantifying Limits on Replication, Death, and Quiescence of Mycobacterium tuberculosis in Mice.

    PubMed

    McDaniel, Margaret M; Krishna, Nitin; Handagama, Winode G; Eda, Shigetoshi; Ganusov, Vitaly V

    2016-01-01

    When an individual is exposed to Mycobacterium tuberculosis (Mtb) three outcomes are possible: bacterial clearance, active disease, or latent infection. It is generally believed that most individuals exposed to Mtb become latently infected and carry the mycobacteria for life. How Mtb is maintained during this latent infection remains largely unknown. During an Mtb infection in mice, there is a phase of rapid increase in bacterial numbers in the murine lungs within the first 3 weeks, and then bacterial numbers either stabilize or increase slowly over the period of many months. It has been debated whether the relatively constant numbers of bacteria in the chronic infection result from latent (dormant, quiescent), non-replicating bacteria, or whether the observed Mtb cell numbers are due to balance between rapid replication and death. A recent study of mice, infected with a Mtb strain carrying an unstable plasmid, showed that during the chronic phase, Mtb was replicating at significant rates. Using experimental data from this study and mathematical modeling we investigated the limits of the rates of bacterial replication, death, and quiescence during Mtb infection of mice. First, we found that to explain the data the rates of bacterial replication and death could not be constant and had to decrease with time since infection unless there were large changes in plasmid segregation probability over time. While a decrease in the rate of Mtb replication with time since infection was expected due to depletion of host's resources, a decrease in the Mtb death rate was counterintuitive since Mtb-specific immune response, appearing in the lungs 3-4 weeks after infection, should increase removal of bacteria. Interestingly, we found no significant correlation between estimated rates of Mtb replication and death suggesting the decline in these rates was driven by independent mechanisms. Second, we found that the data could not be explained by assuming that bacteria do not die

  16. Rapamycin reduces fibroblast proliferation without causing quiescence and induces STAT5A/B-mediated cytokine production.

    PubMed

    Gillespie, Zoe E; MacKay, Kimberly; Sander, Michelle; Trost, Brett; Dawicki, Wojciech; Wickramarathna, Aruna; Gordon, John; Eramian, Mark; Kill, Ian R; Bridger, Joanna M; Kusalik, Anthony; Mitchell, Jennifer A; Eskiw, Christopher H

    2015-01-01

    Rapamycin is a well-known inhibitor of the Target of Rapamycin (TOR) signaling cascade; however, the impact of this drug on global genome function and organization in normal primary cells is poorly understood. To explore this impact, we treated primary human foreskin fibroblasts with rapamycin and observed a decrease in cell proliferation without causing cell death. Upon rapamycin treatment chromosomes 18 and 10 were repositioned to a location similar to that of fibroblasts induced into quiescence by serum reduction. Although similar changes in positioning occurred, comparative transcriptome analyses demonstrated significant divergence in gene expression patterns between rapamycin-treated and quiescence-induced fibroblasts. Rapamycin treatment induced the upregulation of cytokine genes, including those from the Interleukin (IL)-6 signaling network, such as IL-8 and the Leukemia Inhibitory Factor (LIF), while quiescent fibroblasts demonstrated up-regulation of genes involved in the complement and coagulation cascade. In addition, genes significantly up-regulated by rapamycin treatment demonstrated increased promoter occupancy of the transcription factor Signal Transducer and Activator of Transcription 5A/B (STAT5A/B). In summary, we demonstrated that the treatment of fibroblasts with rapamycin decreased proliferation, caused chromosome territory repositioning and induced STAT5A/B-mediated changes in gene expression enriched for cytokines. PMID:26652669

  17. Heterochromatin compaction is regulated by Suv4-20h1 to maintains skeletal muscle stem cells quiescence.

    PubMed

    Machado, Léo; Relaix, Frédéric

    2016-01-01

    In this report, Boonsanay and colleagues describe a novel mechanism of maintenance of skeletal muscle stem cells [also known as satellite cells (SCs)] quiescence via the di-methyltransferase Suv4-20h1, regulator of heterochromatin formation. Conditional ablation of Suv4-20h1 in SCs leads notably to the loss of the histone modification H4K20me2 on the distal regulatory element of Myod combined with a relocation of the Myod locus toward a central position in the nucleus. This switch in nuclear compartment is correlated with decreased facultative H3K27me3 associated heterochromatin, and an increase in spontaneously activated MYOD-expressing SCs in homeostatic muscles. Consequently, Suv4-20h1 knock-out SCs demonstrate compromised stem cell potential, as they fail to efficiently self-renew and replenish the SC pool upon muscle injury. Strikingly, restoring MYOD expression alone rescues the levels of facultative chromatin and reverses the loss-of-quiescence phenotype. PMID:27488816

  18. Transcriptional repression of Bmp2 by p21(Waf1/Cip1) links quiescence to neural stem cell maintenance.

    PubMed

    Porlan, Eva; Morante-Redolat, José Manuel; Marqués-Torrejón, María Ángeles; Andreu-Agulló, Celia; Carneiro, Carmen; Gómez-Ibarlucea, Esther; Soto, Atenea; Vidal, Anxo; Ferrón, Sacri R; Fariñas, Isabel

    2013-11-01

    Relative quiescence and self renewal are defining features of adult stem cells, but their potential coordination remains unclear. Subependymal neural stem cells (NSCs) lacking cyclin-dependent kinase (CDK) inhibitor (CKI) 1a (p21) exhibit rapid expansion that is followed by their permanent loss later in life. Here we demonstrate that transcription of the gene encoding bone morphogenetic protein 2 (Bmp2) in NSCs is under the direct negative control of p21 through actions that are independent of CDK. Loss of p21 in NSCs results in increased levels of secreted BMP2, which induce premature terminal differentiation of multipotent NSCs into mature non-neurogenic astrocytes in an autocrine and/or paracrine manner. We also show that the cell-nonautonomous p21-null phenotype is modulated by the Noggin-rich environment of the subependymal niche. The dual function that we describe here provides a physiological example of combined cell-autonomous and cell-nonautonomous functions of p21 with implications in self renewal, linking the relative quiescence of adult stem cells to their longevity and potentiality.

  19. A Hubble Space Telescope study of the underlying white dwarf in the dwarf nova VW Hydri during quiescence

    NASA Technical Reports Server (NTRS)

    Sion, Edward M.; Szkody, Paula; Cheng, Fu-Hua; Huang, Min

    1995-01-01

    We have analyzed a far-ultraviolet spectrum of the dwarf nova VW Hyi obtained during quiescence with the Hubble Space Telescope Faint Object Spectrograph (HST FOS). The observation occurred 10 days after the return to optical quiescence from a superoutburst of VW Hyi. The spectrum reveals a very strong Stark-broadened Ly-alpha absorption with narrow geocoronal emission, and a very rich metallic absorption-line spectrum dominated by strong resonance absorption features of singly and doubly ionized silicon and carbon, the first solid identification of metallic absorption features arising in the accreted atmosphere of the white dwarf. We confirm the reported low-resolution IUE detection of the underlying white dwarf photosphere by Mateo & Szkody. A synthetic spectral analysis with hot, high-gravity LTE model atmospheres yields a best-fit model with the following parameters: T(sub eff) = 22,000 +/- 1000 K, log g = 8.0 +/- 0.3, with chemical abundances for oxygen of 0.3 times solar, for nitrogen of 5 times solar, and for all other heavy elements of 0.15 times solar. Based upon our absorption-line measurements of the observations at different orbital phases, we find no conclusive evidence of equivalent width variations with orbital phase. In the absence of any significant reduction of the white dwarf's core mass by past nova explosions, its lower limit cooling age is approximately 50 million years.

  20. Loss of Cbl and Cbl-b ubiquitin ligases abrogates hematopoietic stem cell quiescence and sensitizes leukemic disease to chemotherapy

    PubMed Central

    An, Wei; Nadeau, Scott A.; Mohapatra, Bhopal C.; Feng, Dan; Zutshi, Neha; Storck, Matthew D.; Arya, Priyanka; Talmadge, James E.; Meza, Jane L.; Band, Vimla; Band, Hamid

    2015-01-01

    Cbl and Cbl-b are tyrosine kinase-directed RING finger type ubiquitin ligases (E3s) that negatively regulate cellular activation pathways. E3 activity-disrupting human Cbl mutations are associated with myeloproliferative disorders (MPD) that are reproduced in mice with Cbl RING finger mutant knock-in or hematopoietic Cbl and Cbl-b double knockout. However, the role of Cbl proteins in hematopoietic stem cell (HSC) homeostasis, especially in the context of MPD is unclear. Here we demonstrate that HSC expansion and MPD development upon combined Cbl and Cbl-b deletion are dependent on HSCs. Cell cycle analysis demonstrated that DKO HSCs exhibit reduced quiescence associated with compromised reconstitution ability and propensity to undergo exhaustion. We show that sustained c-Kit and FLT3 signaling in DKO HSCs promotes loss of colony-forming potential, and c-Kit or FLT3 inhibition in vitro protects HSCs from exhaustion. In vivo, treatment with 5-fluorouracil hastens DKO HSC exhaustion and protects mice from death due to MPD. Our data reveal a novel and leukemia therapy-relevant role of Cbl and Cbl-b in the maintenance of HSC quiescence and protection against exhaustion, through negative regulation of tyrosine kinase-coupled receptor signaling. PMID:25871390

  1. Gabapentin versus levodopa-c for the treatment of restless legs syndrome in hemodialysis patients: a randomized clinical trial.

    PubMed

    Razazian, Nazanin; Azimi, Hamid; Heidarnejadian, Jafar; Afshari, Daryoush; Ghadami, Mohammad Rasoul

    2015-03-01

    To compare the efficacy of gabapentin and levodopa-c (Levodopa/Carbidopa) in reducing restless leg syndrome (RLS) symptoms and sleep problems in hemodialysis patients with RLS in a four-week randomized clinical trial. The diagnosis of RLS was made using the criteria of the International Restless Legs Study Group. Each subject completed three questionnaires: IRLS questionnaire, Pittsburgh Sleep Quality Index and Epworth sleepiness scale. After four weeks of washout period for previous treatments for RLS, subjects were randomly assigned to four weeks of gabapentin (200 mg) or levodopa-c (110 mg). After four weeks of therapy, the questionnaires administered at the outset of the study were re-administered. Both drugs were found effective for the management of RLS. But, the effect of gabapentin was more significant. Gabapentin significantly improved the IRLS total score (change from baseline to post-treatment ≈-17) compared with levodopa-c (change from baseline to post-treatment ≈-13) (P: 0.016). Regarding sleep parameters, levodopa improved sleep quality, sleep latency and sleep duration (P <0.0001). Gabapentin was also effective with respect to sleep parameters (P <0.0001). Our study shows that gabapentin is a safe effective therapy for RLS among hemodialysis patients. This medication may be considered as an alternative or additive treatment to current therapeutic remedies for hemodialysis patients with RLS.

  2. A Remarkable Three Hour Thermonuclear Burst from 4U 1820-30

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    We present a detailed observational and theoretical study of an approximately three hour long X-ray burst (the "super burst") observed by the Rossi X-ray Timing Explorer (RXTE) from the low mass X-ray binary (LMXB) 4U 1820-30. This is the longest X-ray burst ever observed from this source, and perhaps one of the longest ever observed in great detail from any source. We show that the super burst is thermonuclear in origin. Its peak luminosity of approximately 3.4 x 10(exp 38) ergs s(exp -1) is consistent with the helium Eddington limit for a neutron star at approximately 7 kpc, as well as the peak luminosity of other, shorter, thermonuclear bursts from the same source. The super burst begins in the decaying tail of a more typical (approximately equal to 20 s duration) thermonuclear burst. These shorter, more frequent bursts are well known helium flashes from this source. The level of the accretion driven flux as well as the observed energy release of upwards of 1.5 x 10(exp 42) ergs indicate that helium could not be the energy source for the super burst. We outline the physics relevant to carbon production and burning on helium accreting neutron stars and present calculations of the thermal evolution and stability of a carbon layer and show that this process is the most likely explanation for the super burst. Ignition at the temperatures in the deep carbon "ocean" requires greater than 30 times the mass of carbon inferred from the observed burst energetics unless the He flash is able to trigger a deflagration from a much smaller mass of carbon. We show, however, that for large columns of accreted carbon fuel, a substantial fraction of the energy released in the carbon burning layer is radiated away as neutrinos, and the heat that is conducted from the burning layer in large part flows inward, only to be released on timescales longer than the observed burst. Thus the energy released during the event possibly exceeds that observed in X-rays by more than a factor of

  3. The effects of variations in nuclear interactions on nucleosynthesis in thermonuclear supernovae

    NASA Astrophysics Data System (ADS)

    Parikh, A.; José, J.; Seitenzahl, I. R.; Röpke, F. K.

    2013-09-01

    Context. Type Ia supernova explosions are violent stellar events important for their contribution to the cosmic abundance of iron peak elements and for their role as cosmological distance indicators. Aims: The impact of nuclear physics uncertainties on nucleosynthesis in thermonuclear supernovae has not been fully explored using comprehensive and systematic studies with multiple models. To better constrain predictions of yields from these phenomena, we investigate thermonuclear reaction rates and weak interaction rates that significantly affect yields in our underlying models. Methods: We have performed a sensitivity study by postprocessing thermodynamic histories from two different hydrodynamic, Chandrasekhar-mass explosion models. We have individually varied all input reaction and, for the first time, weak interaction rates by a factor of ten (up and down) and compared the yields in each case to yields using standard rates. Results: Of the 2305 nuclear reactions in our network, we find that in either model the rates of only 53 reactions affect the yield of any species with an abundance of at least 10-8 M⊙ by at least a factor of two. The rates of the 12C(α,γ), 12C+12C, 20Ne(α,p), 20Ne(α,γ), and 30Si(p,γ) reactions are among those that modify the most yields when varied by a factor of ten. From the individual variation of 658 weak interaction rates in our network by a factor of ten, only the stellar 28Si(β+)28Al, 32S(β+)32P, and 36Ar(β+)36Cl rates significantly affect the yields of species in a model. Additional tests reveal that reaction rate changes over temperatures T > 1.5 GK have the greatest impact and that ratios of radionuclides that may be used as explosion diagnostics change by a factor of ≲2 from the variation of individual rates by a factor of ten. Conclusions: Nucleosynthesis in the two adopted models is relatively robust to variations in individual nuclear reaction and weak interaction rates. Laboratory measurements of a limited number

  4. Igniting the Light Elements: The Los Alamos Thermonuclear Weapon Project, 1942-1952

    SciTech Connect

    Anne C. Fitzpatrick

    1999-07-01

    The American system of nuclear weapons research and development was conceived and developed not as a result of technological determinism, but by a number of individual architects who promoted the growth of this large technologically-based complex. While some of the technological artifacts of this system, such as the fission weapons used in World War II, have been the subject of many historical studies, their technical successors--fusion (or hydrogen) devices--are representative of the largely unstudied highly secret realms of nuclear weapons science and engineering. In the postwar period a small number of Los Alamos Scientific Laboratory's staff and affiliates were responsible for theoretical work on fusion weapons, yet the program was subject to both the provisions and constraints of the US Atomic Energy Commission, of which Los Alamos was a part. The Commission leadership's struggle to establish a mission for its network of laboratories, least of all to keep them operating, affected Los Alamos's leaders' decisions as to the course of weapons design and development projects. Adapting Thomas P. Hughes's ''large technological systems'' thesis, I focus on the technical, social, political, and human problems that nuclear weapons scientists faced while pursuing the thermonuclear project, demonstrating why the early American thermonuclear bomb project was an immensely complicated scientific and technological undertaking. I concentrate mainly on Los Alamos Scientific Laboratory's Theoretical, or T, Division, and its members' attempts to complete an accurate mathematical treatment of the ''Super''--the most difficult problem in physics in the postwar period--and other fusion weapon theories. Although tackling a theoretical problem, theoreticians had to address technical and engineering issues as well. I demonstrate the relative value and importance of H-bomb research over time in the postwar era to scientific, politician, and military participants in this project. I

  5. Rotigotine's effect on PLM-associated blood pressure elevations in restless legs syndrome

    PubMed Central

    Cassel, Werner; Benes, Heike; Kesper, Karl; Rye, David; Sica, Domenic; Winkelman, John W.; Bauer, Lars; Grieger, Frank; Joeres, Lars; Moran, Kimberly; Schollmayer, Erwin; Whitesides, John; Carney, Hannah C.; Walters, Arthur S.; Oertel, Wolfgang; Trenkwalder, Claudia

    2016-01-01

    Objective: This double-blind, placebo-controlled, interventional trial was conducted to investigate the effects of rotigotine patch on periodic limb movement (PLM)–associated nocturnal systolic blood pressure (SBP) elevations. Methods: Patients with moderate to severe restless legs syndrome (RLS) were randomized to rotigotine (optimal dose [1–3 mg/24 h]) or placebo. Continuous beat-to-beat blood pressure (BP) assessments were performed during polysomnography at baseline and at the end of 4-week maintenance. Primary outcome was change in number of PLM-associated SBP elevations (defined as slope of linear regression ≥2.5 mm Hg/beat-to-beat interval over 5 consecutive heartbeats [≥10 mm Hg]). Additional outcomes were total SBP elevations, PLM-associated and total diastolic BP (DBP) elevations, periodic limb movements index (PLMI), and PLM in sleep arousal index (PLMSAI). Results: Of 81 randomized patients, 66 (37 rotigotine, 29 placebo) were included in efficacy assessments. PLM-associated SBP elevations were significantly reduced with rotigotine vs placebo (least squares mean treatment difference [95% confidence interval (CI)] −160.34 [−213.23 to −107.45]; p < 0.0001). Rotigotine-treated patients also had greater reduction vs placebo in total SBP elevations (−161.13 [−264.47 to −57.79]; p = 0.0028), PLM-associated elevations (−88.45 [−126.12 to −50.78]; p < 0.0001), and total DBP elevations (−93.81 [−168.45 to −19.16]; p = 0.0146), PLMI (−32.77 [−44.73 to −20.80]; p < 0.0001), and PLMSAI (−7.10 [−11.93 to −2.26]; p = 0.0047). Adverse events included nausea (rotigotine 23%; placebo 8%), headache (18% each), nasopharyngitis (18%; 8%), and fatigue (13%; 15%). Conclusions: Further investigation is required to determine whether reductions in nocturnal BP elevations observed with rotigotine might modify cardiovascular risk. Classification of evidence: This study provides Class I evidence that for patients with moderate to severe

  6. Cotopaxi volcano's unrest and eruptive activity in 2015: mild awakening after 73 years of quiescence

    NASA Astrophysics Data System (ADS)

    Hidalgo, Silvana; Bernard, Benjamin; Battaglia, Jean; Gaunt, Elizabeth; Barrington, Charlotte; Andrade, Daniel; Ramón, Patricio; Arellano, Santiago; Yepes, Hugo; Proaño, Antonio; Almeida, Stefanie; Sierra, Daniel; Dinger, Florian; Kelly, Peter; Parra, René; Bobrowski, Nicole; Galle, Bo; Almeida, Marco; Mothes, Patricia; Alvarado, Alexandra

    2016-04-01

    Cotopaxi volcano (5,897 m) is located 50 km south of Quito, the capital of Ecuador. The most dangerous hazards of this volcano are the devastating lahars that can be generated by the melting of its ice cap during pyroclastic flow-forming eruptions. The first seismic station was installed in 1976. Cotopaxi has been monitored by the Instituto Geofísico (Escuela Politécnica Nacional) since 1983. Presently the monitoring network is comprised of 11 broadband and 5 short period seismometers, 4 scanning DOAS, 1 infrared and 5 visible cameras, 7 DGPS, 5 tiltmeters, 11 AFM (lahar detectors) and a network of ashmeters. Due to the recent unrest, the monitoring of the volcano has been complemented by campaign airborne Multi-GAS and thermal IR measurements and ground-based mobile DOAS and stationary solar FTIR. After 73 years of quiescence, the first sign of unrest was a progressive increase in the amplitude of transient seismic events in April 2015. Since May 20, an increase in SO2 emissions from ˜500 t/d to ˜3 kt/day was detected followed by the appearance of seismic tremor on June 4. Both SO2 emissions of up to 5 kt/day and seismic tremor were observed until August 14 when a swarm of volcano-tectonic earthquakes preceded the first phreatic explosions. These explosions produced ash and gas columns reaching up to 9 km above the crater. The ash fall produced by the opening phase covered over 500 km2 with a submillimetric deposit corresponding to a mass of 1.65E+8 kg (VEI 1). During this period of explosions, SO2 emission rates up to 24 kt/day were observed, the highest thus far. The ash was dominantly hydrothermally altered and oxidized lithic fragments, hydrothermal minerals (alunite, gypsum), free crystals of plagioclase and pyroxenes, and little juvenile material. Unrest continued after August 14, with three episodes of ash emission. However, the intensity of ash fallout, average seismic amplitude, and SO2 emissions during each successive episode progressively decreased

  7. MULTIWAVELENGTH OBSERVATIONS OF THE GAMMA-RAY BLAZAR PKS 0528+134 IN QUIESCENCE

    SciTech Connect

    Palma, N. I.; Boettcher, M.; Li, Y.; De la Calle, I.; Agudo, I.; Jorstad, S. G.; Joshi, M.; Aller, M.; Aller, H.; Bach, U.; BenItez, E.; Buemi, C. S.; Leto, P.; Escande, L.; Gurwell, M. A.; Heidt, J.; Hiriart, D.; Laehteenmaeki, A.; Larionov, V. M. E-mail: marscher@bu.edu E-mail: jlgomez@iaa.es

    2011-07-01

    We present multiwavelength observations of the ultraluminous blazar-type radio loud quasar PKS 0528+134 in quiescence during the period 2009 July-December. Four Target-of-Opportunity observations with the XMM-Newton satellite in the 0.2-10 keV range were supplemented with optical observations at the MDM Observatory, radio and optical data from the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope and the Very Long Baseline Array, additional X-ray data from the Rossi X-ray Timing Explorer (2-10 keV) and from Suzaku (0.5-10 keV) as well as {gamma}-ray data from the Fermi Large Area Telescope in the 100 MeV-200 GeV range. In addition, publicly available data from the SMARTS blazar monitoring program and the University of Arizona/Steward Observatory Fermi Support program were included in our analysis. We found no evidence of significant flux or spectral variability in {gamma}-rays and most radio bands. However, significant flux variability on a timescale of several hours was found in the optical regime, accompanied by a weak trend of spectral softening with increasing flux. We suggest that this might be the signature of a contribution of unbeamed emission, possibly from the accretion disk, at the blue end of the optical spectrum. The optical flux is weakly polarized with rapid variations of the degree and direction of polarization, while the polarization of the 43 GHz radio core remains steady, perpendicular to the jet direction. Optical spectropolarimetry of the object in the quiescent state suggests a trend of increasing degree of polarization with increasing wavelength, providing additional evidence for an unpolarized emission component, possibly thermal emission from the accretion disk, contributing toward the blue end of the optical spectrum. Over an extended period of several months, PKS 0528+134 shows moderate (amplitude {approx}< 50%) flux variability in the X-rays and most radio frequencies on {approx}1-2 week timescales. We constructed four

  8. Influence of the tritium beta(-) decay on low-temperature thermonuclear burn-up in deuterium-tritium mixtures

    PubMed

    Frolov

    2000-09-01

    Low-temperature (Tthermonuclear burn-up in deuterium-tritium mixtures with various deuterium-tritium-helium-3 ratios is considered. The general dependence is studied for the critical burn-up parameter x(c)=rhor(c) upon the initial temperature T, density rho(0), and tritium molar concentration y for the [D]:y[T]:(1-y)[3He] mixture. In particular, it is shown that, if the tritium concentration y decreases, then the critical burn-up parameter x(c)(T,rho(0),y) grows very quickly (at fixed T and rho(0)). This means that tritium beta(-) decay significantly complicates thermonuclear burn-up in deuterium-tritium mixtures.

  9. EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Physics of the plasma corona in the problem of laser controlled thermonuclear fusion

    NASA Astrophysics Data System (ADS)

    Andreev, N. E.; Gorbunov, Leonid M.; Tikhonchuk, Vladimir T.

    1994-09-01

    A brief analysis is made of the most important nonlinear processes which result from the interaction of laser radiation with thermonuclear targets. lt is shown that problems in the physics of the plasma corona should be an essential part of any programme of research on laser controlled thermonuclear fusion. A list is given of the problems that have to be solved first before going to the next level of laser energies.

  10. Economic impacts on the United States of siting decisions for the international thermonuclear experimental reactor

    SciTech Connect

    Peerenboom, J.P.; Hanson, M.E.; Huddleston, J.R.

    1996-08-01

    This report presents the results of a study that examines and compares the probable short-term economic impacts of the International Thermonuclear Experimental Reactor (ITER) on the United States (U.S.) if (1) ITER were to be sited in the U.S., or (2) ITER were to be sited in one of the other countries that, along with the U.S., is currently participating in the ITER program. Life-cycle costs associated with ITER construction, operation, and decommissioning are analyzed to assess their economic impact. A number of possible U.S. host and U.S. non-host technology and cost-sharing arrangements with the other ITER Parties are examined, although cost-sharing arrangements and the process by which the Parties will select a host country and an ITER site remain open issues. Both national and local/regional economic impacts, as measured by gross domestic product, regional output, employment, net exports, and income, are considered. These impacts represent a portion of the complex, interrelated set of economic considerations that characterize U.S. host and U.S. non-host participation in ITER. A number of other potentially important economic and noneconomic considerations are discussed qualitatively.

  11. Recommendations for a cryogenic system for ITER (International Thermonuclear Experimental Reactor)

    SciTech Connect

    Slack, D.S.

    1989-09-20

    The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Japan, the European Community, the Soviet Union, and the United States. ITER will be a large machine requiring up to 100 kW of refrigeration at 4.5 K to cool its superconducting magnets. Unlike earlier fusion experiments, the ITER cryogenic system must handle pulse loads constituting a large percentage of the total load. These come from neutron heating during a fusion burn and from ac losses during ramping of current in the PF (poloidal field) coils. This paper presents a conceptual design for a cryogenic system that meets ITER requirements. It describes a system with the following features: Only time-proven components are used. The system obtains a high efficiency without use of cold pumps or other developmental components. High reliability is achieved by paralleling compressors and expanders and by using adequate isolation valving. The problem of load fluctuations is solved by a simple load-leveling device. The cryogenic system can be housed in a separate building located at a considerable distance from the ITER core, if desired. The paper also summarizes physical plant size, cost estimates, and means of handling vented helium during magnet quench. 4 refs., 4 figs., 3 tabs.

  12. Medical effects of exposure of human beings to fallout radiation from a thermonuclear explosion.

    PubMed

    Cronkite, E P; Bond, V P; Conard, R A

    1995-05-01

    On March 1, 1954, after detonation of a thermonuclear device on Bikini atoll, an unexpected wind shift resulted in the deposition of radioactive fallout on inhabited atolls. The fallout radiation caused fleeting systemic effects, dose-dependent depression of hematopoiesis and skin burns primarily due to the beta ray component of the fission radionuclides. Within a few weeks, hematopoietic recovery was substantial but slight depression of blood counts was maintained for several years. One case of fatal acute myeloblastic leukemia developed in a boy receiving 1.9 Gy as an infant. Cretinism developed in two boys exposed as infants with estimated thyroidal dose in excess of 50 Gy. Chemical hypothyroidism was detected in several persons. Thyroid adenomas and cancer commenced appearance ten years after exposure and became a major long-term medical problem. There have been no late effects attributable to the beta burns 40 years after exposure. Internal contamination from ingestion and inhalation of radionuclides is detectable. The doses are comparable to background levels in the U.S. There is no detectible decrease in longevity of the exposed Marshallese compared to an unexposed Marshallese population.

  13. Collision Models for Plasma Simulation of Thermonuclear Burn: Comparison of Models and Applications

    NASA Astrophysics Data System (ADS)

    Winske, Dan; Albright, Brian; Bowers, Kevin; Lemons, Don

    2007-11-01

    There is renewed interest in examining plasma physics issues related to thermonuclear burn in inertial confinement fusion (ICF) and fast ignition (FI): e.g., the rate of temperature equilibration of electrons and ions, the formation and/or depletion of high energy tails of ion velocity distributions of ions, the slowing of energetic ions in dense plasmas, etc. To address these types of questions, we have developed a new particle-in-cell (PIC) plasma simulation capability, embodied in the code VPIC. To model TN-burn problems in dense plasmas, we have developed a new Coulomb collision model, based on the use of stochastic differential equations and well-known Spitzer rates to describe the collision process, which was presented at last year's meeting. Here we extend the model to included arbitrary weighting of individual simulation particles, rather than just separate weights for each plasma species, which is a feature intrinsic to VPIC. We compare test cases for plasma relaxation and slowing of fast beams using the new collision model with results obtained from an extension of standard particle-pairing collision models to weighted particles for parameter regimes of interest to ICF and FI.

  14. IGNITION COLUMN DEPTHS OF HELIUM-RICH THERMONUCLEAR BURSTS FROM 4U 1728-34

    SciTech Connect

    Misanovic, Zdenka; Galloway, Duncan K.; Cooper, Randall L.

    2010-08-01

    We analyzed thermonuclear (type I) X-ray bursts observed from the low-mass X-ray binary 4U 1728-34 by RXTE, Chandra, and INTEGRAL. We compared the variation in burst energy and recurrence times as a function of accretion rate with the predictions of a numerical ignition model including a treatment of the heating and cooling in the crust. We found that the measured burst ignition column depths are significantly below the theoretically predicted values, regardless of the assumed thermal structure of the neutron star (NS) interior. While it is possible that the accretion rate measured by Chandra is underestimated, due to additional persistent spectral components outside the sensitivity band, the required correction factor is typically 3.6 and as high as 6, which is implausible. Furthermore, such underestimation is even more unlikely for RXTE and INTEGRAL, which have much broader bandpasses. Possible explanations for the observed discrepancy include shear-triggered mixing of the accreted helium to larger column depths, resulting in earlier ignition, or the fractional covering of the accreted fuel on the NS surface.

  15. Design considerations for ITER (International Thermonuclear Experimental Reactor) toroidal field coils

    SciTech Connect

    Kalsi, S.S.; Lousteau, D.C.; Miller, J.R.

    1987-01-01

    The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Europe, Japan, the Union of Soviet Socialist Republics (USSR), and the United States. This paper describes a magnetic and mechanical design methodology for toroidal field (TF) coils that employs Nb/sub 3/Sn superconductor technology. Coil winding is sized by using conductor concepts developed for the US TIBER concept. The nuclear heating generated during operation is removed from the windings by helium flowing through the conductor. The heat in the coil case is removed through a separate cooling circuit operating at approximately 20 K. Manifold concepts are presented for the complete coil cooling system. Also included are concepts for the coil structural arrangement. The effects of in-plane and out-of-plane loads are included in the design considerations for the windings and case. Concepts are presented for reacting these loads with a minimum amount of additional structural material. Concepts discussed in this paper could be considered for the ITER TF coils. 6 refs., 5 figs., 1 tab.

  16. Vulnerability assessment of a space based weapon platform electronic system exposed to a thermonuclear weapon detonation

    NASA Astrophysics Data System (ADS)

    Perez, C. L.; Johnson, J. O.

    Rapidly changing world events, the increased number of nations with inter-continental ballistic missile capability, and the proliferation of nuclear weapon technology will increase the number of nuclear threats facing the world today. Monitoring these nation's activities and providing an early warning and/or intercept system via reconnaissance and surveillance satellites and space based weapon platforms is a viable deterrent against a surprise nuclear attack. However, the deployment of satellite and weapon platform assets in space will subject the sensitive electronic equipment to a variety of natural and man-made radiation environments. These include Van Allen Belt protons and electrons; galactic and solar flare protons; and neutrons, gamma rays, and x-rays from intentionally detonated fission and fusion weapons. In this paper, the MASH vl.0 code system is used to estimate the dose to the critical electronics components of an idealized space based weapon platform from neutron and gamma-ray radiation emitted from a thermonuclear weapon detonation in space. Fluence and dose assessments were performed for the platform fully loaded, and in several stages representing limited engagement scenarios. The results indicate vulnerabilities to the Command, Control, and Communication bay instruments from radiation damage for a nuclear weapon detonation for certain source/platform orientations. The distance at which damage occurs will depend on the weapon yield (n,(gamma)/kiloton) and size (kilotons).

  17. Thermonuclear ignition in inertial confinement fusion and comparison with magnetic confinementa)

    NASA Astrophysics Data System (ADS)

    Betti, R.; Chang, P. Y.; Spears, B. K.; Anderson, K. S.; Edwards, J.; Fatenejad, M.; Lindl, J. D.; McCrory, R. L.; Nora, R.; Shvarts, D.

    2010-05-01

    The physics of thermonuclear ignition in inertial confinement fusion (ICF) is presented in the familiar frame of a Lawson-type criterion. The product of the plasma pressure and confinement time Pτ for ICF is cast in terms of measurable parameters and its value is estimated for cryogenic implosions. An overall ignition parameter χ including pressure, confinement time, and temperature is derived to complement the product Pτ. A metric for performance assessment should include both χ and Pτ. The ignition parameter and the product Pτ are compared between inertial and magnetic-confinement fusion. It is found that cryogenic implosions on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have achieved Pτ ˜1.5 atm s comparable to large tokamaks such as the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)] where Pτ ˜1 atm s. Since OMEGA implosions are relatively cold (T ˜2 keV), their overall ignition parameter χ ˜0.02-0.03 is ˜5× lower than in JET (χ ˜0.13), where the average temperature is about 10 keV.

  18. Thermonuclear ignition in inertial confinement fusion and comparison with magnetic confinement

    SciTech Connect

    Betti, R.; Chang, P. Y.; Anderson, K. S.; Nora, R.; Spears, B. K.; Edwards, J.; Lindl, J. D.; Fatenejad, M.; McCrory, R. L.; Shvarts, D.

    2010-05-15

    The physics of thermonuclear ignition in inertial confinement fusion (ICF) is presented in the familiar frame of a Lawson-type criterion. The product of the plasma pressure and confinement time Ptau for ICF is cast in terms of measurable parameters and its value is estimated for cryogenic implosions. An overall ignition parameter chi including pressure, confinement time, and temperature is derived to complement the product Ptau. A metric for performance assessment should include both chi and Ptau. The ignition parameter and the product Ptau are compared between inertial and magnetic-confinement fusion. It is found that cryogenic implosions on OMEGA[T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have achieved Ptauapprox1.5 atm s comparable to large tokamaks such as the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)] where Ptauapprox1 atm s. Since OMEGA implosions are relatively cold (Tapprox2 keV), their overall ignition parameter chiapprox0.02-0.03 is approx5x lower than in JET (chiapprox0.13), where the average temperature is about 10 keV.

  19. Antenna design for fast ion collective Thomson scattering diagnostic for the international thermonuclear experimental reactor.

    PubMed

    Leipold, F; Furtula, V; Salewski, M; Bindslev, H; Korsholm, S B; Meo, F; Michelsen, P K; Moseev, D; Nielsen, S K; Stejner, M

    2009-09-01

    Fast ion physics will play an important role for the international thermonuclear experimental reactor (ITER), where confined alpha particles will affect and be affected by plasma dynamics and thereby have impacts on the overall confinement. A fast ion collective Thomson scattering (CTS) diagnostic using gyrotrons operated at 60 GHz will meet the requirements for spatially and temporally resolved measurements of the velocity distributions of confined fast alphas in ITER by evaluating the scattered radiation (CTS signal). While a receiver antenna on the low field side of the tokamak, resolving near perpendicular (to the magnetic field) velocity components, has been enabled, an additional antenna on the high field side (HFS) would enable measurements of near parallel (to the magnetic field) velocity components. A compact design solution for the proposed mirror system on the HFS is presented. The HFS CTS antenna is located behind the blankets and views the plasma through the gap between two blanket modules. The viewing gap has been modified to dimensions 30x500 mm(2) to optimize the CTS signal. A 1:1 mock-up of the HFS mirror system was built. Measurements of the beam characteristics for millimeter-waves at 60 GHz used in the mock-up agree well with the modeling.

  20. Bulk-bronzied graphites for plasma-facing components in ITER (International Thermonuclear Experimental Reactor)

    SciTech Connect

    Hirooka, Y.; Conn, R.W.; Doerner, R.; Khandagle, M. . Inst. of Plasma and Fusion Research); Causey, R.; Wilson, K. ); Croessmann, D.; Whitley, J. ); Holland, D.; Smolik, G. ); Matsuda, T.; Sogabe, T. (Toyo Tanso Co. Ltd., O

    1990-06-01

    Newly developed bulk-boronized graphites and boronized C-C composites with a total boron concentration ranging from 1 wt % to 30 wt % have been evaluated as plasma-facing component materials for the International Thermonuclear Experimental Reactor (ITER). Bulk-boronized graphites have been bombarded with high-flux deuterium plasmas at temperatures between 200 and 1600{degree}C. Plasma interaction induced erosion of bulk-boronized graphites is observed to be a factor of 2--3 smaller than that of pyrolytic graphite, in regimes of physical sputtering, chemical sputtering and radiation enhanced sublimation. Postbombardment thermal desorption spectroscopy indicates that bulk-boronized graphites enhance recombinative desorption of deuterium, which leads to a suppression of the formation of deuterocarbon due to chemical sputtering. The tritium inventory in graphite has been found to decrease by an order of magnitude due to 10 wt % bulk-boronization at temperatures above 1000{degree}C. The critical heat flux to induce cracking for bulk-boronized graphites has been found to be essentially the same as that for non-boronized graphites. Also, 10 wt % bulk-boronization of graphite hinders air oxidation nearly completely at 800{degree}C and reduces the steam oxidation rate by a factor of 2--3 at around 1100 and 1350{degree}C. 38 refs., 5 figs.

  1. Thermonuclear runaways in nova outbursts. 2: Effect of strong, instantaneous, local fluctuations

    NASA Technical Reports Server (NTRS)

    Shankar, Anurag; Arnett, David

    1994-01-01

    In an attempt to understand the manner in which nova outbursts are initiated on the surface of a white dwarf, we investigate the effects fluctuations have on the evolution of a thermonuclear runaway. Fluctuations in temperature density, or the composition of material in the burning shell may arise due to the chaotic flow field generated by convection when it occurs, or by the accretion process itself. With the aid of two-dimensional reactive flow calculations, we consider cases where a strong fluctutation in temperature arises during the early, quiescent accretion phase or during the later, more dynamic, explosion phase. In all cases we find that an instantaneous, local temperature fluctuation causes the affected material to become Rayleigh-Taylor unstable. The rapid rise and subsequent expansion of matter immediately cools the hot blob, which prevents the lateral propagation of burning. This suggests that local temperature fluctuations do not play a significant role in directly initiating the runaway, especially during the early stages. However, they may provide an efficient mechanism of mixing core material into the envelope (thereby pre-enriching the fuel for subsequent episodes of explosive hydrogen burning) and of mixing substantial amounts of the radioactive nucleus N-13 into the surface layers, making novae potential gamma-ray sources. This suggests that it is the global not the local, evolution of the core-envelope interface to high temperatures which dominates the development of the runaway. We also present a possible new scenario for the initiation of nova outbursts based on our results.

  2. Rotational effects in thermonuclear type I bursts: equatorial crossing and directionality of flame spreading

    NASA Astrophysics Data System (ADS)

    Cavecchi, Yuri; Watts, Anna L.; Levin, Yuri; Braithwaite, Jonathan

    2015-03-01

    In a previous study on thermonuclear (type I) bursts on accreting neutron stars, we addressed and demonstrated the importance of the effects of rotation, through the Coriolis force, on the propagation of the burning flame. However, that study only analysed cases of longitudinal propagation, where the Coriolis force coefficient 2Ωcos θ was constant. In this paper, we study the effects of rotation on propagation in the meridional (latitudinal) direction, where the Coriolis force changes from its maximum at the poles to zero at the equator. We find that the zero Coriolis force at the equator, while affecting the structure of the flame, does not prevent its propagation from one hemisphere to another. We also observe structural differences between the flame propagating towards the equator and that propagating towards the pole, the second being faster. In the light of the recent discovery of the low spin frequency of burster IGR J17480-2446 rotating at 11 Hz (for which Coriolis effects should be negligible), we also extend our simulations to slow rotation.

  3. Transmission of Thermonuclear Detonations through Layers of Burned Material in Carbon-Oxygen White Dwarfs

    NASA Astrophysics Data System (ADS)

    Gamezo, V. N.; Oran, E. S.

    2006-06-01

    In three-dimensional delayed-detonation models of type Ia supernovae, detonations propagate through funnels of degenerate carbon-oxygen matter that are left unburned by turbulent deflagrations in central parts of a white dwarf. Some of these funnels can be disconnected from the rest of the unburned material, thus creating unburned pockets that cannot be directly reached by a detonation wave. These pockets may or may not ignite when strong shocks generated by detonations reach them through layers of burned material. In this work, we study the detonation transmission phenomena in exploding white dwarfs using one-dimensional time-dependent numerical simulations based on reactive Euler equations. The thermonuclear burning of carbon-oxygen mixture is modeled by a 13-nuclei alpha network. We use a steady-state solution for the reaction-zone structure of a one-dimensional detonation wave as an initial condition. Time-dependent computations performed for a fully resolved carbon reaction scale show that a detonation shock passing through a layer of burned material can initiate a new detonation or decay. The critical thickness of burned material that allows the detonation reignition is a function of density. This work was supported in part by the NASA ATP program (NRA-02-OSS-01-ATP) and by the Naval Research Laboratory (NRL) through the Office of Naval Research.

  4. Thermonuclear targets for direct-drive ignition by a megajoule laser pulse

    SciTech Connect

    Bel’kov, S. A.; Bondarenko, S. V.; Vergunova, G. A.; Garanin, S. G.; Gus’kov, S. Yu. Demchenko, N. N.; Doskoch, I. Ya.; Kuchugov, P. A.; Zmitrenko, N. V.; Rozanov, V. B.; Stepanov, R. V.; Yakhin, R. A.

    2015-10-15

    Central ignition of a thin two-layer-shell fusion target that is directly driven by a 2-MJ profiled pulse of Nd laser second-harmonic radiation has been studied. The parameters of the target were selected so as to provide effective acceleration of the shell toward the center, which was sufficient for the onset of ignition under conditions of increased hydrodynamic stability of the ablator acceleration and compression. The aspect ratio of the inner deuterium-tritium layer of the shell does not exceed 15, provided that a major part (above 75%) of the outer layer (plastic ablator) is evaporated by the instant of maximum compression. The investigation is based on two series of numerical calculations that were performed using one-dimensional (1D) hydrodynamic codes. The first 1D code was used to calculate the absorption of the profiled laser-radiation pulse (including calculation of the total absorption coefficient with allowance for the inverse bremsstrahlung and resonance mechanisms) and the spatial distribution of target heating for a real geometry of irradiation using 192 laser beams in a scheme of focusing with a cubo-octahedral symmetry. The second 1D code was used for simulating the total cycle of target evolution under the action of absorbed laser radiation and for determining the thermonuclear gain that was achieved with a given target.

  5. Signalling couples hair follicle stem cell quiescence with reduced histone H3 K4/K9/K27me3 for proper tissue homeostasis

    PubMed Central

    Lee, Jayhun; Kang, Sangjo; Lilja, Karin C.; Colletier, Keegan J.; Scheitz, Cornelia Johanna Franziska; Zhang, Ying V.; Tumbar, Tudorita

    2016-01-01

    Mechanisms of plasticity to acquire different cell fates are critical for adult stem cell (SC) potential, yet are poorly understood. Reduced global histone methylation is an epigenetic state known to mediate plasticity in cultured embryonic SCs and T-cell progenitors. Here we find histone H3 K4/K9/K27me3 levels actively reduced in adult mouse skin and hair follicle stem cells (HFSCs) during G0 quiescence. The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs. Skin hypomethylation during quiescence was necessary for subsequent progression of hair homeostasis (cycle). Inhibiting BMP signal, a known HFSC anti-proliferative factor, elevated HFSC methylation in vivo during quiescence prior to proliferation onset. Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells. We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis. PMID:27080563

  6. Signalling couples hair follicle stem cell quiescence with reduced histone H3 K4/K9/K27me3 for proper tissue homeostasis.

    PubMed

    Lee, Jayhun; Kang, Sangjo; Lilja, Karin C; Colletier, Keegan J; Scheitz, Cornelia Johanna Franziska; Zhang, Ying V; Tumbar, Tudorita

    2016-04-15

    Mechanisms of plasticity to acquire different cell fates are critical for adult stem cell (SC) potential, yet are poorly understood. Reduced global histone methylation is an epigenetic state known to mediate plasticity in cultured embryonic SCs and T-cell progenitors. Here we find histone H3 K4/K9/K27me3 levels actively reduced in adult mouse skin and hair follicle stem cells (HFSCs) during G0 quiescence. The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs. Skin hypomethylation during quiescence was necessary for subsequent progression of hair homeostasis (cycle). Inhibiting BMP signal, a known HFSC anti-proliferative factor, elevated HFSC methylation in vivo during quiescence prior to proliferation onset. Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells. We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis.

  7. Signalling couples hair follicle stem cell quiescence with reduced histone H3 K4/K9/K27me3 for proper tissue homeostasis.

    PubMed

    Lee, Jayhun; Kang, Sangjo; Lilja, Karin C; Colletier, Keegan J; Scheitz, Cornelia Johanna Franziska; Zhang, Ying V; Tumbar, Tudorita

    2016-01-01

    Mechanisms of plasticity to acquire different cell fates are critical for adult stem cell (SC) potential, yet are poorly understood. Reduced global histone methylation is an epigenetic state known to mediate plasticity in cultured embryonic SCs and T-cell progenitors. Here we find histone H3 K4/K9/K27me3 levels actively reduced in adult mouse skin and hair follicle stem cells (HFSCs) during G0 quiescence. The level of marks over specific gene promoters did not correlate to mRNA level changes in quiescent HFSCs. Skin hypomethylation during quiescence was necessary for subsequent progression of hair homeostasis (cycle). Inhibiting BMP signal, a known HFSC anti-proliferative factor, elevated HFSC methylation in vivo during quiescence prior to proliferation onset. Furthermore, removal of proliferation factors and addition of BMP4 reduced histone methylases and increased demethylases mRNAs in cultured skin epithelial cells. We conclude that signalling couples hair follicle stem cell quiescence with reduced H3 K4/K9/K27me3 levels for proper tissue homeostasis. PMID:27080563

  8. WI-38 cell long-term quiescence model system: a valuable tool to study molecular events that regulate growth.

    PubMed

    Soprano, K J

    1994-04-01

    A number of cell culture model systems have been used to study the regulation of cell cycle progression at the molecular level. In this paper we describe the WI-38 cell long-term quiescence model system. By modulating the length of time that WI-38 cells are density arrested, it is possible to proportionately alter the length of the prereplicative or G-1 phase which the cell traverses after growth factor stimulation in preparation for entry into DNA synthesis. Through studies aimed at understanding the cause and molecular nature of the prolongation of the prereplicative phase, we have determined that gene expression plays an important role in establishing growth factor "competence" and that once the cell becomes "competent" there is a defined order to the molecular events that follow during the remainder of G-1. More specifically, we have determined that the prolongation represents a delay in the ability of long term quiescent cells to become fully "competent" to respond to growth factors which regulate progression through G-1 into S. This prolongation appears to occur as a result of changes during long term quiescence in the ability of immediate early G-1 specific genes (such as c-myc) to activate the expression of early G-1 specific genes (such as ornithine decarboxylase). While ODC is the first and thus far only growth associated gene identified as a target of c-myc (and the Myc/Max protein complex), it is likely that further studies in this model system will reveal other early G-1 growth regulatory genes. We anticipate that future follow-up studies in this model system will provide additional valuable information about the function of growth-regulatory genes in controlling growth factor responsiveness and cell cycle progression.

  9. Specific biomarkers for stochastic division patterns and starvation-induced quiescence under limited glucose levels in fission yeast

    PubMed Central

    Pluskal, Tomáš; Hayashi, Takeshi; Saitoh, Shigeaki; Fujisawa, Asuka; Yanagida, Mitsuhiro

    2011-01-01

    Glucose as a source of energy is centrally important to our understanding of life. We investigated the cell division–quiescence behavior of the fission yeast Schizosaccharomyces pombe under a wide range of glucose concentrations (0–111 mm). The mode of S. pombe cell division under a microfluidic perfusion system was surprisingly normal under highly diluted glucose concentrations (5.6 mm, 1/20 of the standard medium, within human blood sugar levels). Division became stochastic, accompanied by a curious division-timing inheritance, in 2.2–4.4 mm glucose. A critical transition from division to quiescence occurred within a narrow range of concentrations (2.2–1.7 mm). Under starvation (1.1 mm) conditions, cells were mostly quiescent and only a small population of cells divided. Under fasting (0 mm) conditions, division was immediately arrested with a short chronological lifespan (16 h). When cells were first glucose starved prior to fasting, they possessed a substantially extended lifespan (∼14 days). We employed a quantitative metabolomic approach for S. pombe cell extracts, and identified specific metabolites (e.g. biotin, trehalose, ergothioneine, S-adenosyl methionine and CDP-choline), which increased or decreased at different glucose concentrations, whereas nucleotide triphosphates, such as ATP, maintained high concentrations even under starvation. Under starvation, the level of S-adenosyl methionine increased sharply, accompanied by an increase in methylated amino acids and nucleotides. Under fasting, cells rapidly lost antioxidant and energy compounds, such as glutathione and ATP, but, in fasting cells after starvation, these and other metabolites ensuring longevity remained abundant. Glucose-starved cells became resistant to 40 mm H2O2 as a result of the accumulation of antioxidant compounds. PMID:21306563

  10. THE X-RAY PROPERTIES OF THE BLACK HOLE TRANSIENT MAXI J1659-152 IN QUIESCENCE

    SciTech Connect

    Homan, Jeroen; Fridriksson, Joel K.; Altamirano, Diego; Jonker, Peter G.; Russell, David M.; Gallo, Elena; Kuulkers, Erik; Rea, Nanda

    2013-09-20

    We present new Chandra X-ray observations of the transient black hole X-ray binary MAXI J1659-152 in quiescence. These observations were made more than one year after the end of the source's 2010-2011 outburst. We detect the source at a 0.5-10 keV flux of 2.8(8) Multiplication-Sign 10{sup -15} erg s{sup -1} cm{sup -2}, which corresponds to a luminosity of {approx}1.2 Multiplication-Sign 10{sup 31} (d/6 kpc){sup 2} erg s{sup -1}. This level, while being the lowest at which the source has been detected, is within factors of {approx}2 of the levels seen at the end of the initial decay of the outburst and soon after a major reflare of the source. The quiescent luminosity of MAXI J1659-152, which is the shortest-orbital-period black hole X-ray binary ({approx}2.4 hr), is lower than that of neutron-star X-ray binaries with similar periods. However, it is higher than the quiescent luminosities found for black hole X-ray binaries with orbital periods {approx}2-4 times longer. This could imply that a minimum quiescent luminosity may exist for black hole X-ray binaries, around orbital periods of {approx}5-10 hr, as predicted by binary-evolution models for the mass transfer rate. Compared to the hard state, we see a clear softening of the power-law spectrum in quiescence, from an index of 1.55(4) to an index of 2.5(4). We constrain the luminosity range in which this softening starts to (0.18-6.2) Multiplication-Sign 10{sup -5} (d/6 kpc){sup 2} (M/8 M{sub Sun }) L{sub Edd}, which is consistent with the ranges inferred for other sources.

  11. Sensitivity study of explosive nucleosynthesis in type Ia supernovae: Modification of individual thermonuclear reaction rates

    NASA Astrophysics Data System (ADS)

    Bravo, Eduardo; Martínez-Pinedo, Gabriel

    2012-05-01

    Background: Type Ia supernovae contribute significantly to the nucleosynthesis of many Fe-group and intermediate-mass elements. However, the robustness of nucleosynthesis obtained via models of this class of explosions has not been studied in depth until now.Purpose: We explore the sensitivity of the nucleosynthesis resulting from thermonuclear explosions of massive white dwarfs with respect to uncertainties in nuclear reaction rates. We put particular emphasis on indentifying the individual reactions rates that most strongly affect the isotopic products of these supernovae.Method: We have adopted a standard one-dimensional delayed detonation model of the explosion of a Chandrasekhar-mass white dwarf and have postprocessed the thermodynamic trajectories of every mass shell with a nucleosynthetic code to obtain the chemical composition of the ejected matter. We have considered increases (decreases) by a factor of 10 on the rates of 1196 nuclear reactions (simultaneously with their inverse reactions), repeating the nucleosynthesis calculations after modification of each reaction rate pair. We have computed as well hydrodynamic models for different rates of the fusion reactions of 12C and of 16O. From the calculations we have selected the reactions that have the largest impact on the supernova yields, and we have computed again the nucleosynthesis using two or three alternative prescriptions for their rates, taken from the JINA REACLIB database. For the three reactions with the largest sensitivity we have analyzed as well the temperature ranges where a modification of their rates has the strongest effect on nucleosynthesis.Results: The nucleosynthesis resulting from the type Ia supernova models is quite robust with respect to variations of nuclear reaction rates, with the exception of the reaction of fusion of two 12C nuclei. The energy of the explosion changes by less than ˜4% when the rates of the reactions 12C+12C or 16O+16O are multiplied by a factor of ×10 or

  12. Development of multifilamentary niobium titanium and niobium tin strands for the International Thermonuclear Experimental Reactor project

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Zhang, P. X.; Tang, X. D.; Liu, X. H.; Lu, Y. F.; Weng, P. D.; Grunblatt, G.; Hoang, Gia K.; Verwaerde, C.

    2007-05-01

    The International Thermonuclear Experimental Reactor(ITER) device should demonstrate the scientific and technological possibility of commercial fusion energy production in large scale in order to solve the worldwide energy problem in the future. The superconducting magnet system is the key part of the ITER device to supply high magnetic fields for confining the deuterium-tritium plasma. The multifilament NbTi and Nb3Sn strands with high quality have been studied to meet the specifications of superconducting strands for fabricating poloidal field coils (PF) and toroidal field coils (TF). For NbTi strands with 8306 filaments, Jc of 2910 A mm-2 (4.2 K, 5 T, 0.1 μV cm-1) has been obtained by a conventional process. The proposed process could be used for fabrication of long strands with a unit length more than 5000 m. By an internal tin process the multifilamentary Nb3Sn strands with a diameter of 0.79 mm and a unit length longer than 5000 m have been successfully fabricated. The highest non-Cu Jcn (12 T, 4.2 K, 0.1 μV cm-1) value of 1249 A mm-2 has been obtained. The n-value of Nb3Sn strands is larger than 20 and the residual resistance ratio (RRR) value lies between 150 and 220. The formation of the Nb3Sn superconducting phase together with the evolution of microstructure has been investigated by neutron diffraction and scanning electron microscopy. The results indicate that the properties of NbTi and Nb3Sn strands have already met basically the specifications proposed by the ITER program.

  13. Evidence of thermonuclear flame spreading on neutron stars from burst rise oscillations

    SciTech Connect

    Chakraborty, Manoneeta; Bhattacharyya, Sudip E-mail: sudip@tifr.res.in

    2014-09-01

    Burst oscillations during the rising phases of thermonuclear X-ray bursts are usually believed to originate from flame spreading on the neutron star surface. However, the decrease of fractional oscillation amplitude with rise time, which provides a main observational support for the flame spreading model, have so far been reported from only a few bursts. Moreover, the non-detection and intermittent detections of rise oscillations from many bursts are not yet understood considering the flame spreading scenario. Here, we report the decreasing trend of fractional oscillation amplitude from an extensive analysis of a large sample of Rossi X-ray Timing Explorer Proportional Counter Array bursts from 10 neutron star low-mass X-ray binaries. This trend is 99.99% significant for the best case, which provides, to the best of our knowledge, by far the strongest evidence of such a trend. Moreover, it is important to note that an opposite trend is not found in any of the bursts. The concave shape of the fractional amplitude profiles for all the bursts suggests latitude-dependent flame speeds, possibly due to the effects of the Coriolis force. We also systematically study the roles of low fractional amplitude and low count rate for non-detection and intermittent detections of rise oscillations, and attempt to understand them within the flame spreading scenario. Our results support a weak turbulent viscosity for flame spreading, and imply that burst rise oscillations originate from an expanding hot spot, thus making these oscillations a more reliable tool to constrain the neutron star equations of state.

  14. Vulnerability assessment of a space based weapon platform electronics system exposed to a thermonuclear weapon detonation

    SciTech Connect

    Perez, C.L.; Johnson, J.O.

    1994-05-01

    The utilization of reconnaissance/surveillance satellite and weapon platform assets in space will subject the sensitive electronic equipment to a variety of natural and man-made radiation environments. These include Van Allen Belt protons and electrons; galactic and solar flare protons; neutrons, gamma rays, and X-rays from fission and fusion weapons; and directed neutral particle beams and lasers. Electronic equipment, including modem integrated circuits, may undergo permanent or transient changes of the electrical properties of the active components when exposed to these sources of radiation. This report summarizes the results of the Monte Carlo Adjoint Shielding code system -- MASH v1.0 calculations designed to estimate the dose to the critical electronics components of an idealized spaced based weapon platform from neutron and gamma-ray radiation emanating from a thermonuclear weapon detonation. The MASH calculations modeled several source/platform geometry configurations, obtaining results for multiple distances and weapon detonation positions relative to the platform. For certain source/platform orientations, the results indicate vulnerabilities to the C{sup 3} bay critical components box to radiation damage from a nuclear weapon detonation. Neutron protection factors ranged from 0.7 to 3.4 for the three platform configurations analyzed, and gamma-ray protection factors ranged from approximately 1.5 to 9.8. The results further indicate the source has a direct line-of-sight to the critical components box for certain source/platform orientations, regardless of the number of interceptors present. The merits of utilizing the MASH code system for estimating dose and shielding factors for spaced based assets has been demonstrated. The geometry configuration studied here is greatly simplified compared to those that will be encountered in an actual design.

  15. Reaction rate and composition dependence of the stability of thermonuclear burning on accreting neutron stars

    SciTech Connect

    Keek, L.; Cyburt, R. H.; Heger, A.

    2014-06-01

    The stability of thermonuclear burning of hydrogen and helium accreted onto neutron stars is strongly dependent on the mass accretion rate. The burning behavior is observed to change from Type I X-ray bursts to stable burning, with oscillatory burning occurring at the transition. Simulations predict the transition at a 10 times higher mass accretion rate than observed. Using numerical models we investigate how the transition depends on the hydrogen, helium, and CNO mass fractions of the accreted material, as well as on the nuclear reaction rates of 3α and the hot-CNO breakout reactions {sup 15}O(α, γ){sup 19}Ne and {sup 18}Ne(α, p){sup 21}Na. For a lower hydrogen content the transition is at higher accretion rates. Furthermore, most experimentally allowed reaction rate variations change the transition accretion rate by at most 10%. A factor 10 decrease of the {sup 15}O(α, γ){sup 19}Ne rate, however, produces an increase of the transition accretion rate of 35%. None of our models reproduce the transition at the observed rate, and depending on the true {sup 15}O(α, γ){sup 19}Ne reaction rate, the actual discrepancy may be substantially larger. We find that the width of the interval of accretion rates with marginally stable burning depends strongly on both composition and reaction rates. Furthermore, close to the stability transition, our models predict that X-ray bursts have extended tails where freshly accreted fuel prolongs nuclear burning.

  16. Transmission thermography for inspecting the busbar insulation layer in thermonuclear experimental reactor

    NASA Astrophysics Data System (ADS)

    Chen, Dapeng; Zhang, Guang; Zhang, Xiaolong; Zeng, Zhi

    2014-11-01

    In Thermonuclear Experimental Reactor, Superconducting Busbar is used for current transmission between magnet coils and current leads. The work temperature of the Busbar is about 4K because of liquid helium via inside. The large temperature grad from 300K to 4K could lead to the defects and damages occur on the insulation layer, which is made of glass fiber and polyimide and has a big different thermal expansion coefficient compared with the metal inner cylinder. This paper aims at developing an infrared transmission non-destructive evaluation (NDE) method for inspecting the insulation layer of Superconducting Busbar; theoretical model of transient heat conduction under a continuous inner heat source for cylindrical structure is described in the paper; a Busbar specimen which is designed with three delamination defects of different depths is heated inside by pouring hot water and monitored by an infrared detector located outside. Results demonstrate excellent detection performance for delamination defects in the insulation layer by using transmission thermography, all of the three defects of different depths can be visualized clearly in the thermal images, and the deeper defect has a better signal contrast, which is also shown in the temperature difference between defects and sound area vs. time curves. The results of light pulse thermography is also shown as a comparison, and it is found that the thermal images obtained by the transmission thermography has a much better signal contrast than that of the pulse thermography. In order to verify the experiments, finite element method is applied to simulate the heat conduction in the Busbar under the continuous inside heating, and it is found that the simulated temperature vs. time and simulated temperature difference vs. time curves are basically coincident with the experimental results. In addition, the possibility of in-service inspection for Busbar insulation layer in ITER item is discussed.

  17. An accretion disk swept up by a powerful thermonuclear X-ray burst

    NASA Astrophysics Data System (ADS)

    Degenaar, Nathalie

    Type-I X-ray bursts are thermonuclear explosions occurring in the surface layers of accreting neutron stars. These events are powerful probes of the physics of neutron stars and their surrounding accretion flow. Swift recently caught a very energetic type-I X-ray burst from the neutron star IGR J17062-6143 that displayed exceptional features. Firstly, the light curve of the 18 minute long X-ray burst tail shows an episode of 10 minutes with wild X-ray intensity fluctuations. Secondly, X-ray spectral analysis revealed a highly significant emission line around 1 keV, which can be interpreted as an Fe-L shell line caused by the irradiation of cold gas. Finally, the detection of significant absorption lines and edges in the Fe-K band are strongly suggestive of the presence of hot, highly ionized gas along the line of sight. None of these features are present in the persistent emission of the source. The X-ray burst of IGR J17062-6143 shows the first unambiguous detection of atomic features at CCD resolution. The timescale of the strong intensity variations, the velocity width of the Fe-L emission line, and photo-ionization modeling of the Fe-K absorption features each independently point to swept-up gas at a radius of ~1000 km from the neutron star. The unusual X-ray light curve and spectral properties could have plausibly been caused by a disruption of the accretion disk due to the super-Eddington fluxes reached during the X-ray burst.

  18. ON THE CONSISTENCY OF NEUTRON-STAR RADIUS MEASUREMENTS FROM THERMONUCLEAR BURSTS

    SciTech Connect

    Galloway, Duncan K.; Lampe, Nathanael

    2012-03-01

    The radius of neutron stars can in principle be measured via the normalization of a blackbody fitted to the X-ray spectrum during thermonuclear (type-I) X-ray bursts, although few previous studies have addressed the reliability of such measurements. Here we examine the apparent radius in a homogeneous sample of long, mixed H/He bursts from the low-mass X-ray binaries GS 1826-24 and KS 1731-26. The measured blackbody normalization (proportional to the emitting area) in these bursts is constant over a period of up to 60 s in the burst tail, even though the flux (blackbody temperature) decreased by a factor of 60%-75% (30%-40%). The typical rms variation in the mean normalization from burst to burst was 3%-5%, although a variation of 17% was found between bursts observed from GS 1826-24 in two epochs. A comparison of the time-resolved spectroscopic measurements during bursts from the two epochs shows that the normalization evolves consistently through the burst rise and peak, but subsequently increases further in the earlier epoch bursts. The elevated normalization values may arise from a change in the anisotropy of the burst emission or alternatively variations in the spectral correction factor, f{sub c} , of order 10%. Since burst samples observed from systems other than GS 1826-24 are more heterogeneous, we expect that systematic uncertainties of at least 10% are likely to apply generally to measurements of neutron-star radii, unless the effects described here can be corrected for.

  19. Restless behavior increases over time, but not with compressibility of the flooring surface, during forced standing at the feed bunk.

    PubMed

    Krebs, N; Berry, S L; Tucker, C B

    2011-01-01

    Interest in the use of rubber flooring in freestall barns has increased, but little is known about which design features of these surfaces are important for cattle. In 2 experiments, we evaluated how the type and compressibility of the flooring surface in front of the feed bunk influenced the behavioral response to 4 h of forced standing after morning milking. Two flooring types were compared: rubber and concrete. Rubber was tested at 3 levels of compressibility: 2, 4, and 35 times as compressible as concrete. Four hours of forced standing was evaluated because it mimicked conditions that can occur on dairies, particularly when waiting for artificial insemination or veterinary treatment. The effects of cow weight and hoof surface area, gait score, and hoof health on the response to treatment were evaluated. Restless behavior, as measured by number of steps, almost doubled over the 4h of forced standing, regardless of flooring material. Cows lay down, on average, within 5 min after access to the lying area was provided. These results indicate that the 4 h of forced standing was uncomfortable. No differences in restless behavior were observed in association with the type or compressibility of the flooring surface in front of the feed bunk. Cow size, hoof health, or gait score did not consistently explain the response to the flooring treatments or stepping rate, although these populations of animals were generally healthy. It is unclear if comfort did not differ between the flooring options tested during 4 h of forced standing or if alterative methodology, such as measuring more subtle shifts in weight, is required to assess design features of rubber flooring.

  20. The prevalence of restless legs syndrome in Edirne and its districts concomitant comorbid conditions and secondary complications.

    PubMed

    Güler, Sibel; Caylan, Ayşe; Nesrin Turan, F; Dağdeviren, Nezih; Çelik, Yahya

    2015-10-01

    We aimed to determine the prevalence and risk factors of restless legs syndrome in Edirne and its districts, located in Western Thrace, which is the most western part of Turkey. In this study, 4003 individuals who could communicate and agreed to participate in the study were evaluated. To obtain the data from the applicants in 30 Family Health Centres in Edirne and its districts, a face-to-face questionnaire that consisted of 54 questions was prepared by the researchers. The questionnaire included general information, questions to evaluate potential concomitant comorbid conditions and questions regarding the symptomatology used in restless legs syndrome (RLS) diagnosis, as well as questions to evaluate insomnia and tension-type headache secondary to insomnia according to the ICD-II Criteria (International Classification of Sleep Disorders-II Criteria). Of 4003 individuals, 282 were diagnosed with RLS according to the questionnaire results from Edirne and its districts, and the prevalence of RLS was 7%. Approximately, 47.9% of the patients with RLS were male, and 52.1% were female, which was not significantly different (p > 0.05). Anaemia was identified in 41.1 % of the cases and control group was detected in 19.4 %, which was significantly different (p < 0.001). Secondary insomnia was identified in 64.2% of the cases with RLS and was not detected in 35.8%, which was significantly different (p < 0.001). RLS prevalence studies will increase the awareness of the community and provide early diagnosis and treatment, as well as serve as a basis to reduce morbidity and improve the quality of life.

  1. High concentrations of HGF inhibit skeletal muscle satellite cell proliferation in vitro by inducing expression of myostatin: a possible mechanism for reestablishing satellite cell quiescence in vivo

    PubMed Central

    Yamada, Michiko; Yamanouchi, Keitaro; Hosoyama, Tohru; Shiratsuchi, Sei-ichi; Sato, Akiko; Mizunoya, Wataru; Ikeuchi, Yoshihide; Furuse, Mitsuhiro; Allen, Ronald E.

    2010-01-01

    Skeletal muscle regeneration and work-induced hypertrophy rely on molecular events responsible for activation and quiescence of resident myogenic stem cells, satellite cells. Recent studies demonstrated that hepatocyte growth factor (HGF) triggers activation and entry into the cell cycle in response to mechanical perturbation, and that subsequent expression of myostatin may signal a return to cell quiescence. However, mechanisms responsible for coordinating expression of myostatin after an appropriate time lag following activation and proliferation are not clear. Here we address the possible role of HGF in quiescence through its concentration-dependent negative-feedback mechanism following satellite cell activation and proliferation. When activated/proliferating satellite cell cultures were treated for 24 h beginning 48-h postplating with 10–500 ng/ml HGF, the percentage of bromodeoxyuridine-incorporating cells decreased down to a baseline level comparable to 24-h control cultures in a HGF dose-dependent manner. The high level HGF treatment did not impair the cell viability and differentiation levels, and cells could be reactivated by lowering HGF concentrations to 2.5 ng/ml, a concentration that has been shown to optimally stimulate activation of satellite cells in culture. Coaddition of antimyostatin neutralizing antibody could prevent deactivation and abolish upregulation of cyclin-dependent kinase (Cdk) inhibitor p21. Myostatin mRNA expression was upregulated with high concentrations of HGF, as demonstrated by RT-PCR, and enhanced myostatin protein expression and secretion were revealed by Western blots of the cell lysates and conditioned media. These results indicate that HGF could induce satellite cell quiescence by stimulating myostatin expression. The HGF concentration required (over 10–50 ng/ml), however, is much higher than that for activation, which is initiated by rapid release of HGF from its extracellular association. Considering that HGF is

  2. High concentrations of HGF inhibit skeletal muscle satellite cell proliferation in vitro by inducing expression of myostatin: a possible mechanism for reestablishing satellite cell quiescence in vivo.

    PubMed

    Yamada, Michiko; Tatsumi, Ryuichi; Yamanouchi, Keitaro; Hosoyama, Tohru; Shiratsuchi, Sei-ichi; Sato, Akiko; Mizunoya, Wataru; Ikeuchi, Yoshihide; Furuse, Mitsuhiro; Allen, Ronald E

    2010-03-01

    Skeletal muscle regeneration and work-induced hypertrophy rely on molecular events responsible for activation and quiescence of resident myogenic stem cells, satellite cells. Recent studies demonstrated that hepatocyte growth factor (HGF) triggers activation and entry into the cell cycle in response to mechanical perturbation, and that subsequent expression of myostatin may signal a return to cell quiescence. However, mechanisms responsible for coordinating expression of myostatin after an appropriate time lag following activation and proliferation are not clear. Here we address the possible role of HGF in quiescence through its concentration-dependent negative-feedback mechanism following satellite cell activation and proliferation. When activated/proliferating satellite cell cultures were treated for 24 h beginning 48-h postplating with 10-500 ng/ml HGF, the percentage of bromodeoxyuridine-incorporating cells decreased down to a baseline level comparable to 24-h control cultures in a HGF dose-dependent manner. The high level HGF treatment did not impair the cell viability and differentiation levels, and cells could be reactivated by lowering HGF concentrations to 2.5 ng/ml, a concentration that has been shown to optimally stimulate activation of satellite cells in culture. Coaddition of antimyostatin neutralizing antibody could prevent deactivation and abolish upregulation of cyclin-dependent kinase (Cdk) inhibitor p21. Myostatin mRNA expression was upregulated with high concentrations of HGF, as demonstrated by RT-PCR, and enhanced myostatin protein expression and secretion were revealed by Western blots of the cell lysates and conditioned media. These results indicate that HGF could induce satellite cell quiescence by stimulating myostatin expression. The HGF concentration required (over 10-50 ng/ml), however, is much higher than that for activation, which is initiated by rapid release of HGF from its extracellular association. Considering that HGF is produced

  3. THE FERMI-GBM X-RAY BURST MONITOR: THERMONUCLEAR BURSTS FROM 4U 0614+09

    SciTech Connect

    Linares, M.; Chakrabarty, D.; Connaughton, V.; Bhat, P. N.; Briggs, M. S.; Preece, R.; Jenke, P.; Kouveliotou, C.; Wilson-Hodge, C. A.; Camero-Arranz, A.; Finger, M.; Paciesas, W. S.; Beklen, E.; Von Kienlin, A.

    2012-12-01

    Thermonuclear bursts from slowly accreting neutron stars (NSs) have proven difficult to detect, yet they are potential probes of the thermal properties of the NS interior. During the first year of a systematic all-sky search for X-ray bursts using the Gamma-ray Burst Monitor aboard the Fermi Gamma-ray Space Telescope we have detected 15 thermonuclear bursts from the NS low-mass X-ray binary 4U 0614+09 when it was accreting at nearly 1% of the Eddington limit. We measured an average burst recurrence time of 12 {+-} 3 days (68% confidence interval) between 2010 March and 2011 March, classified all bursts as normal duration bursts and placed a lower limit on the recurrence time of long/intermediate bursts of 62 days (95% confidence level). We discuss how observations of thermonuclear bursts in the hard X-ray band compare to pointed soft X-ray observations and quantify such bandpass effects on measurements of burst radiated energy and duration. We put our results for 4U 0614+09 in the context of other bursters and briefly discuss the constraints on ignition models. Interestingly, we find that the burst energies in 4U 0614+09 are on average between those of normal duration bursts and those measured in long/intermediate bursts. Such a continuous distribution in burst energy provides a new observational link between normal and long/intermediate bursts. We suggest that the apparent bimodal distribution that defined normal and long/intermediate duration bursts during the last decade could be due to an observational bias toward detecting only the longest and most energetic bursts from slowly accreting NSs.

  4. The Fermi-GBM X-Ray Burst Monitor: Thermonuclear Bursts from 4U 0614+09

    NASA Astrophysics Data System (ADS)

    Linares, M.; Connaughton, V.; Jenke, P.; van der Horst, A. J.; Camero-Arranz, A.; Kouveliotou, C.; Chakrabarty, D.; Beklen, E.; Bhat, P. N.; Briggs, M. S.; Finger, M.; Paciesas, W. S.; Preece, R.; von Kienlin, A.; Wilson-Hodge, C. A.

    2012-12-01

    Thermonuclear bursts from slowly accreting neutron stars (NSs) have proven difficult to detect, yet they are potential probes of the thermal properties of the NS interior. During the first year of a systematic all-sky search for X-ray bursts using the Gamma-ray Burst Monitor aboard the Fermi Gamma-ray Space Telescope we have detected 15 thermonuclear bursts from the NS low-mass X-ray binary 4U 0614+09 when it was accreting at nearly 1% of the Eddington limit. We measured an average burst recurrence time of 12 ± 3 days (68% confidence interval) between 2010 March and 2011 March, classified all bursts as normal duration bursts and placed a lower limit on the recurrence time of long/intermediate bursts of 62 days (95% confidence level). We discuss how observations of thermonuclear bursts in the hard X-ray band compare to pointed soft X-ray observations and quantify such bandpass effects on measurements of burst radiated energy and duration. We put our results for 4U 0614+09 in the context of other bursters and briefly discuss the constraints on ignition models. Interestingly, we find that the burst energies in 4U 0614+09 are on average between those of normal duration bursts and those measured in long/intermediate bursts. Such a continuous distribution in burst energy provides a new observational link between normal and long/intermediate bursts. We suggest that the apparent bimodal distribution that defined normal and long/intermediate duration bursts during the last decade could be due to an observational bias toward detecting only the longest and most energetic bursts from slowly accreting NSs.

  5. Ion heating and thermonuclear neutron production from high-intensity subpicosecond laser pulses interacting with underdense plasmas.

    PubMed

    Fritzler, S; Najmudin, Z; Malka, V; Krushelnick, K; Marle, C; Walton, B; Wei, M S; Clarke, R J; Dangor, A E

    2002-10-14

    Thermonuclear fusion neutrons produced by D(d,n)3He reactions have been measured from the interaction of a high-intensity laser with underdense deuterium plasmas. For an input laser energy of 62 J, more than (1.0+/-0.2)x10(6) neutrons with a mean kinetic energy of (2.5+/-0.2) MeV were detected. These neutrons were observed to have an isotropic angular emission profile. By comparing these measurements with those using a secondary solid CD2 target it was determined that neutrons are produced from direct ion heating during this interaction.

  6. High luminosity, slow ejecta and persistent carbon lines: SN 2009dc challenges thermonuclear explosion scenarios

    NASA Astrophysics Data System (ADS)

    Taubenberger, S.; Benetti, S.; Childress, M.; Pakmor, R.; Hachinger, S.; Mazzali, P. A.; Stanishev, V.; Elias-Rosa, N.; Agnoletto, I.; Bufano, F.; Ergon, M.; Harutyunyan, A.; Inserra, C.; Kankare, E.; Kromer, M.; Navasardyan, H.; Nicolas, J.; Pastorello, A.; Prosperi, E.; Salgado, F.; Sollerman, J.; Stritzinger, M.; Turatto, M.; Valenti, S.; Hillebrandt, W.

    2011-04-01

    Extended optical and near-IR observations reveal that SN 2009dc shares a number of similarities with normal Type Ia supernovae (SNe Ia), but is clearly overluminous, with a (pseudo-bolometric) peak luminosity of log (L) = 43.47 (erg s-1). Its light curves decline slowly over half a year after maximum light [Δm15(B)true= 0.71], and the early-time near-IR light curves show secondary maxima, although the minima between the first and the second peaks are not very pronounced. The bluer bands exhibit an enhanced fading after ˜200 d, which might be caused by dust formation or an unexpectedly early IR catastrophe. The spectra of SN 2009dc are dominated by intermediate-mass elements and unburned material at early times, and by iron-group elements at late phases. Strong C II lines are present until ˜2 weeks past maximum, which is unprecedented in thermonuclear SNe. The ejecta velocities are significantly lower than in normal and even subluminous SNe Ia. No signatures of interaction with a circumstellar medium (CSM) are found in the spectra. Assuming that the light curves are powered by radioactive decay, analytic modelling suggests that SN 2009dc produced ˜1.8 M⊙ of 56Ni assuming the smallest possible rise time of 22 d. Together with a derived total ejecta mass of ˜2.8 M⊙, this confirms that SN 2009dc is a member of the class of possible super-Chandrasekhar-mass SNe Ia similar to SNe 2003fg, 2006gz and 2007if. A study of the hosts of SN 2009dc and other superluminous SNe Ia reveals a tendency of these SNe to explode in low-mass galaxies. A low metallicity of the progenitor may therefore be an important prerequisite for producing superluminous SNe Ia. We discuss a number of possible explosion scenarios, ranging from super-Chandrasekhar-mass white-dwarf progenitors over dynamical white-dwarf mergers and Type I? SNe to a core-collapse origin of the explosion. None of the models seems capable of explaining all properties of SN 2009dc, so that the true nature of this SN

  7. Study of Thermonuclear Alfven Instabilities in Next Step Burning Plasma Experiments

    SciTech Connect

    N.N. Gorelenkov; H.L. Berk; R. Budny; C.Z. Cheng; G.-Y. Fu; W.W. Heidbrink; G. Kramer; D. Meade; and R. Nazikian

    2002-07-02

    A study is presented for the stability of alpha-particle driven shear Alfven Eigenmodes (AE) for the normal parameters of the three major burning plasma proposals, ITER (International Thermonuclear Experimental Reactor), FIRE (Fusion Ignition Research Experiment), and IGNITOR (Ignited Torus). A study of the JET (Joint European Torus) plasma, where fusion alphas were generated in tritium experiments, is also included to attempt experimental validation of the numerical predictions. An analytic assessment of Toroidal AE (TAE) stability is first presented, where the alpha particle beta due to the fusion reaction rate and electron drag is simply and accurately estimated in 7-20 keV plasma temperature regime. In this assessment the hot particle drive is balanced against ion-Landau damping of the background deuterons and electron collision effects and stability boundaries are determined. Then two numerical studies of AE instability are presented. In one the High-n stability code HINST is used . This code is capable of predicting instabilities of low and moderately high frequency Alfven modes. HINST computes the non-perturbative solution of the Alfven eigenmodes including effects of ion finite Larmor radius, orbit width, trapped electrons etc. The stability calculations are repeated using the global code NOVAK. We show that for these tokamaks the spectrum of the least stable AE modes are TAE that appear at medium-/high-n numbers. In HINST TAEs are locally unstable due to the alphas pressure gradient in all the devices under the consideration except IGNITOR. However, NOVAK calculations show that the global mode structure enhances the damping mechanisms and produces stability in all configurations considered here. A serious question remains whether the perturbation theory used in NOVAK overestimates the stability predictions, so that it is premature to conclude that the nominal operation of all three proposals are stable to AEs. In addition NBI ions produce a strong

  8. Magnetohydrodynamic-calibrated edge-localized mode model in simulations of International Thermonuclear Experimental Reactor

    NASA Astrophysics Data System (ADS)

    Onjun, Thawatchai; Kritz, Arnold H.; Bateman, Glenn; Parail, Vassili

    2005-08-01

    Self-consistent simulations of the International Thermonuclear Experimental Reactor (ITER) [R. Aymar, P. Barabaschi, and Y. Shimomura, Plasma Phys. Controlled Fusion 44, 519 (2002)] have been carried out using the JETTO-integrated modeling code in which theory-motivated models are used for the H-mode pedestal and for the stability conditions that lead to the edge-localized mode (ELM) crashes. Transport is described by combining the anomalous mixed Bohm/gyro-Bohm model [M. Erba, A. Cherubini, V. V. Parail, and A. Taroni, Plasma Phys. Controlled Fusion 39, 261 (1997)] with the NCLASS neoclassical transport model [W. A. Houlberg, K. C. Shaing, S. P. Hirshman, and M. C. Zarnstorff, Phys. Plasmas 4, 3231 (1997)] in the core region, while only neoclassical transport is used in the pedestal region. In the simulations, an ELM crash can be triggered either by a pressure-driven ballooning mode or by a current-driven peeling mode, depending on which instability reaches its stability criterion first. The equilibrium and magnetohydrodynamics (MHD) stability analyses codes, HELENA and MISHKA [A. B. Mikhailovskii, G. T. A. Huysmans, S. E. Sharapov, and W. Kerner, Plasma Phys. Rep. 23, 713 (1997)], are used to evaluate the edge stability of the plasma just prior to an ELM crash in order to calibrate and confirm the validity of the stability criteria used to trigger ELMs in the JETTO simulations. It is found that the simulation of the ITER baseline case yields a fusion Q of 16.6, with the electron and ion temperatures at the top of the pedestal of 4.4 and 4.9keV, respectively. The high values of the pedestal temperature result from access to the second stability region of the ballooning mode. Simulation sensitivity studies are carried out by varying parameters such as the auxiliary heating power and the width of the pedestal. When the auxiliary heating power is turned off, it is found that significant fusion power is sustained and that access to ballooning mode second stability is

  9. Accretion and Outflows in X-ray Binaries: What's Really Going on During X-ray Quiescence

    NASA Astrophysics Data System (ADS)

    MacDonald, Rachel K. D.; Bailyn, Charles D.; Buxton, Michelle

    2015-01-01

    X-ray binaries, consisting of a star and a stellar-mass black hole, are wonderful laboratories for studying accretion and outflows. They evolve on timescales quite accessible to us, unlike their supermassive cousins, and allow the possibility of gaining a deeper understanding of these two common astrophysical processes. Different wavelength regimes reveal different aspects of the systems: radio emission is largely generated by outflows and jets, X-ray emission by inner accretion flows, and optical/infrared (OIR) emission by the outer disk and companion star. The search for relationships between these different wavelengths is thus an area of active research, aiming to reveal deeper connections between accretion and outflows.Initial evidence for a strong, tight correlation between radio and X-ray emission has weakened as further observations and newly-discovered sources have been obtained. This has led to discussions of multiple tracks or clusters, or the possibility that no overall relation exists for the currently-known population of X-ray binaries. Our ability to distinguish among these options is hampered by a relative lack of observations at lower luminosities, and especially of truly X-ray quiescent (non-outbursting) systems. Although X-ray binaries spend the bulk of their existence in quiescence, few quiescent sources have been observed and multiple observations of individual sources are largely nonexistent. Here we discuss new observations of the lowest-luminosity quiescent X-ray binary, A0620-00, and the place this object occupies in investigations of the radio/X-ray plane. For the first time, we also incorporate simultaneous OIR data with the radio and X-ray data.In December 2013 we took simultaneous observations of A0620-00 in the X-ray (Chandra), the radio (EVLA), and the OIR (SMARTS 1.3m). These X-ray and radio data allowed us to investigate similarities among quiescent X-ray binaries, and changes over time for this individual object, in the radio

  10. Optical spectroscopy of EX Lupi during quiescence and outburst. Infall, wind, and dynamics in the accretion flow

    NASA Astrophysics Data System (ADS)

    Sicilia-Aguilar, A.; Kóspál, Á.; Setiawan, J.; Ábrahám, P.; Dullemond, C.; Eiroa, C.; Goto, M.; Henning, Th.; Juhász, A.

    2012-08-01

    Context. EX Lupi is the prototype of EXor variables. After 50 years of mild variability and smaller outbursts, the object again experienced a large outburst in 2008. Aims: We explore the accretion mechanisms in EX Lupi during its pre-outburst, outburst, and post-outburst phases. Methods: We analyze 10 high-resolution optical spectra of EX Lupi, taken before, during, and after the 2008 outburst. In both quiescence and outburst, the star presents many permitted emission lines. These include lines typical of accreting T Tauri stars, plus a large number of neutral and ionized metallic lines (mostly Fe I and Fe II). During the outburst, the number of emission lines increases to about a thousand, and their structure shows a narrow and a broad component (NC and BC). We study the structure of the BC, which is highly variable on short timescales (24-72 h). Results: An active chromosphere can explain the metallic lines in quiescence and the outburst NC. The dynamics of the BC line profiles suggest that these profiles originate in a hot, dense, non-axisymmetric, and non-uniform accretion column that suffers velocity variations along the line-of-sight on timescales of days. Assuming Keplerian rotation, the emitting region would be located at ~0.1-0.2 AU, which is consistent with the location of the inner disk rim, but the velocity profiles of the lines reveal a combination of rotation and infall. Line ratios of ions and neutrals can be reproduced assuming a temperature of T ~ 6500 K for electron densities of a few times 1012 cm-3 in the line-emitting region. The line profiles also indicate that there is an accretion-related inner disk wind. Conclusions: The data confirm that the 2008 outburst was an episode of increased accretion, albeit much stronger than previous EX Lupi and typical EXors outbursts. The line profiles are consistent with the infall/rotation of a non-axisymmetric structure that could be produced by clumpy accretion during the outburst phase. A strong inner

  11. Nocturnal eating/drinking syndrome with restless legs syndrome caused by neuroleptics improved by Yi-Gan San add-on treatment: a case report.

    PubMed

    Kawabe, Kentaro; Ueno, Shu-ichi; Hosoda, Yoshiki; Horiguchi, Jun

    2012-01-01

    Nocturnal eating/drinking syndrome is characterized by awakening in the middle of the night, getting out of bed, and consuming large quantities of food quickly and uncontrollably. We report a middle-aged male patient with schizophrenia who had nocturnal eating/drinking syndrome with restless legs syndrome whose condition improved with the administration of the herbal medicine Yi-Gan San (Yokukan-San in Japanese).

  12. SOAR observations of the high-viscosity accretion disc of the dwarf nova V4140 Sagitarii in quiescence and in outburst

    NASA Astrophysics Data System (ADS)

    Baptista, Raymundo; Borges, Bernardo W.; Oliveira, Alexandre S.

    2016-09-01

    We report the analysis of 22 B-band light curves of the dwarf nova V4140 Sgr obtained with SOI/SOAR during two nights along the decline of a superoutburst in 2006 Sep 12-24 and in quiescence over 50 days following the superoutburst. Three-dimensional eclipse mapping of the outburst light curves indicates that the accretion disc is elliptical (eccentricity e = 0.13) and that superhump maximum occurs when the mass donor star is aligned with the bulge of the elliptical disc. The accretion disc is geometrically thin both in outburst and in quiescence; it fills the primary Roche lobe in outburst and shrinks to about half this size in quiescence. The stability of the eclipse shape, width and depth along quiescence and the derived disc surface brightness distribution indicate that the quiescent accretion disc is in a high-viscosity, steady-state. Flickering mapping of the quiescent data reveal that the low-frequency flickering arises from an azimuthally-extended stream-disc impact region at disc rim and from the innermost disc region, whereas the high-frequency flickering originates in the accretion disc. Assuming the disc-related flickering to be caused by fluctuations in the energy dissipation rate induced by magneto-hydrodynamic turbulence (Geertsema & Achterberg 1992), we find that the quiescent disc viscosity parameter is large α ≃ 0.2 - 0.4 at all radii. The high-viscosity quiescent disc and the inferred low disc temperatures in superoutburst are inconsistent with expectations of the disc-instability model, and lead to the conclusion that the outbursts of V4140 Sgr are powered by mass transfer bursts from its donor star.

  13. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes.

    PubMed

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C J

    2015-02-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes.

  14. FOXC1 maintains the hair follicle stem cell niche and governs stem cell quiescence to preserve long-term tissue-regenerating potential.

    PubMed

    Lay, Kenneth; Kume, Tsutomu; Fuchs, Elaine

    2016-03-15

    Adult tissue stem cells (SCs) reside in niches, which orchestrate SC behavior. SCs are typically used sparingly and exist in quiescence unless activated for tissue growth. Whether parsimonious SC use is essential to conserve long-term tissue-regenerating potential during normal homeostasis remains poorly understood. Here, we examine this issue by conditionally ablating a key transcription factor Forkhead box C1 (FOXC1) expressed in hair follicle SCs (HFSCs). FOXC1-deficient HFSCs spend less time in quiescence, leading to markedly shortened resting periods between hair cycles. The enhanced hair cycling accelerates HFSC expenditure, and impacts hair regeneration in aging mice. Interestingly, although FOXC1-deficient HFs can still form a new bulge that houses HFSCs for the next hair cycle, the older bulge is left unanchored. As the new hair emerges, the entire old bulge, including its reserve HFSCs and SC-inhibitory inner cell layer, is lost. We trace this mechanism first, to a marked increase in cell cycle-associated transcripts upon Foxc1 ablation, and second, to a downstream reduction in E-cadherin-mediated inter-SC adhesion. Finally, we show that when the old bulge is lost with each hair cycle, overall levels of SC-inhibitory factors are reduced, further lowering the threshold for HFSC activity. Taken together, our findings suggest that HFSCs have restricted potential in vivo, which they conserve by coupling quiescence to adhesion-mediated niche maintenance, thereby achieving long-term tissue homeostasis.

  15. FOXC1 maintains the hair follicle stem cell niche and governs stem cell quiescence to preserve long-term tissue-regenerating potential.

    PubMed

    Lay, Kenneth; Kume, Tsutomu; Fuchs, Elaine

    2016-03-15

    Adult tissue stem cells (SCs) reside in niches, which orchestrate SC behavior. SCs are typically used sparingly and exist in quiescence unless activated for tissue growth. Whether parsimonious SC use is essential to conserve long-term tissue-regenerating potential during normal homeostasis remains poorly understood. Here, we examine this issue by conditionally ablating a key transcription factor Forkhead box C1 (FOXC1) expressed in hair follicle SCs (HFSCs). FOXC1-deficient HFSCs spend less time in quiescence, leading to markedly shortened resting periods between hair cycles. The enhanced hair cycling accelerates HFSC expenditure, and impacts hair regeneration in aging mice. Interestingly, although FOXC1-deficient HFs can still form a new bulge that houses HFSCs for the next hair cycle, the older bulge is left unanchored. As the new hair emerges, the entire old bulge, including its reserve HFSCs and SC-inhibitory inner cell layer, is lost. We trace this mechanism first, to a marked increase in cell cycle-associated transcripts upon Foxc1 ablation, and second, to a downstream reduction in E-cadherin-mediated inter-SC adhesion. Finally, we show that when the old bulge is lost with each hair cycle, overall levels of SC-inhibitory factors are reduced, further lowering the threshold for HFSC activity. Taken together, our findings suggest that HFSCs have restricted potential in vivo, which they conserve by coupling quiescence to adhesion-mediated niche maintenance, thereby achieving long-term tissue homeostasis. PMID:26912458

  16. T cell exit from quiescence and differentiation into Th2 cells depend on Raptor-mTORC1-mediated metabolic programming

    PubMed Central

    Yang, Kai; Shrestha, Sharad; Zeng, Hu; Karmaus, Peer W.F.; Neale, Geoffrey; Vogel, Peter; Guertin, David A.; Lamb, Richard F.; Chi, Hongbo

    2014-01-01

    SUMMARY Naïve T cells respond to antigen stimulation by exiting from quiescence and initiating clonal expansion and functional differentiation, but the control mechanism is elusive. Here we describe that Raptor-mTORC1-dependent metabolic programming is a central determinant of this transitional process. Loss of Raptor abrogated T cell priming and Th2 cell differentiation, although Raptor function is less important for continuous proliferation of actively cycling cells. mTORC1 coordinated multiple metabolic programs in T cells including glycolysis, lipid synthesis and oxidative phosphorylation to mediate antigen-triggered exit from quiescence. mTORC1 further linked glucose metabolism to the initiation of Th2 cell differentiation by orchestrating cytokine receptor expression and cytokine responsiveness. Activation of Raptor-mTORC1 integrated T cell receptor and CD28 co-stimulatory signals in antigen-stimulated T cells. Our studies identify a Raptor-mTORC1-dependent pathway linking signal-dependent metabolic reprogramming to quiescence exit, and this in turn coordinates lymphocyte activation and fate decisions in adaptive immunity. PMID:24315998

  17. A fine balance: epigenetic control of cellular quiescence by the tumor suppressor PRDM2/RIZ at a bivalent domain in the cyclin a gene

    PubMed Central

    Cheedipudi, Sirisha; Puri, Deepika; Saleh, Amena; Gala, Hardik P.; Rumman, Mohammed; Pillai, Malini S.; Sreenivas, Prethish; Arora, Reety; Sellathurai, Jeeva; Schrøder, Henrik Daa; Mishra, Rakesh K.; Dhawan, Jyotsna

    2015-01-01

    Adult stem cell quiescence is critical to ensure regeneration while minimizing tumorigenesis. Epigenetic regulation contributes to cell cycle control and differentiation, but few regulators of the chromatin state in quiescent cells are known. Here we report that the tumor suppressor PRDM2/RIZ, an H3K9 methyltransferase, is enriched in quiescent muscle stem cells in vivo and controls reversible quiescence in cultured myoblasts. We find that PRDM2 associates with >4400 promoters in G0 myoblasts, 55% of which are also marked with H3K9me2 and enriched for myogenic, cell cycle and developmental regulators. Knockdown of PRDM2 alters histone methylation at key promoters such as Myogenin and CyclinA2 (CCNA2), and subverts the quiescence program via global de-repression of myogenesis, and hyper-repression of the cell cycle. Further, PRDM2 acts upstream of the repressive PRC2 complex in G0. We identify a novel G0-specific bivalent chromatin domain in the CCNA2 locus. PRDM2 protein interacts with the PRC2 protein EZH2 and regulates its association with the bivalent domain in the CCNA2 gene. Our results suggest that induction of PRDM2 in G0 ensures that two antagonistic programs—myogenesis and the cell cycle—while stalled, are poised for reactivation. Together, these results indicate that epigenetic regulation by PRDM2 preserves key functions of the quiescent state, with implications for stem cell self-renewal. PMID:26040698

  18. FOXC1 maintains the hair follicle stem cell niche and governs stem cell quiescence to preserve long-term tissue-regenerating potential

    PubMed Central

    Lay, Kenneth; Kume, Tsutomu; Fuchs, Elaine

    2016-01-01

    Adult tissue stem cells (SCs) reside in niches, which orchestrate SC behavior. SCs are typically used sparingly and exist in quiescence unless activated for tissue growth. Whether parsimonious SC use is essential to conserve long-term tissue-regenerating potential during normal homeostasis remains poorly understood. Here, we examine this issue by conditionally ablating a key transcription factor Forkhead box C1 (FOXC1) expressed in hair follicle SCs (HFSCs). FOXC1-deficient HFSCs spend less time in quiescence, leading to markedly shortened resting periods between hair cycles. The enhanced hair cycling accelerates HFSC expenditure, and impacts hair regeneration in aging mice. Interestingly, although FOXC1-deficient HFs can still form a new bulge that houses HFSCs for the next hair cycle, the older bulge is left unanchored. As the new hair emerges, the entire old bulge, including its reserve HFSCs and SC-inhibitory inner cell layer, is lost. We trace this mechanism first, to a marked increase in cell cycle-associated transcripts upon Foxc1 ablation, and second, to a downstream reduction in E-cadherin–mediated inter-SC adhesion. Finally, we show that when the old bulge is lost with each hair cycle, overall levels of SC-inhibitory factors are reduced, further lowering the threshold for HFSC activity. Taken together, our findings suggest that HFSCs have restricted potential in vivo, which they conserve by coupling quiescence to adhesion-mediated niche maintenance, thereby achieving long-term tissue homeostasis. PMID:26912458

  19. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

    NASA Astrophysics Data System (ADS)

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-01

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  20. Tor1, Sch9 and PKA downregulation in quiescence rely on Mtl1 to preserve mitochondrial integrity and cell survival.

    PubMed

    Sundaram, Venkatraghavan; Petkova, Mima I; Pujol-Carrion, Nuria; Boada, Jordi; de la Torre-Ruiz, Maria Angeles

    2015-07-01

    Here we show that Mtl1, member of the cell wall integrity pathway of Saccharomyces cerevisiae, plays a positive role in chronological life span (CLS). The absence of Mtl1 shortens CLS and causes impairment in the mitochondrial function. This is reflected in a descent in oxygen consumption during the postdiauxic state, an increase in the uncoupled respiration and mitochondrial membrane potential and also a descent in aconitase activity. We demonstrate that all these effects are a consequence of signalling defects suppressed by TOR1 (target of rapamycin) and SCH9 deletion and less efficiently by Protein kinase A (PKA) inactivation. Mtl1 also plays a role in the regulation of both Bcy1 stability and phosphorylation, mainly in response to glucose depletion. In postdiauxic phase and in conditions of glucose depletion, Mtl1 negatively regulates TOR1 function leading to Sch9 inactivation and Bcy1 phosphorylation converging in PKA inhibition. Slt2/Mpk1 kinase partially contributes to Bcy1 phosphorylation, although additional targets are not excluded. Mtl1 links mitochondrial dysfunction with TOR and PKA pathways in quiescence, glucose being the main signalling molecule.

  1. The Transcriptional Repressor Polycomb Group Factor 6, PCGF6, Negatively Regulates Dendritic Cell Activation and Promotes Quiescence.

    PubMed

    Boukhaled, Giselle M; Cordeiro, Brendan; Deblois, Genevieve; Dimitrov, Vassil; Bailey, Swneke D; Holowka, Thomas; Domi, Anisa; Guak, Hannah; Chiu, Huai-Hsuan Clare; Everts, Bart; Pearce, Edward J; Lupien, Mathieu; White, John H; Krawczyk, Connie M

    2016-08-16

    Pro-inflammatory signals provided by the microenvironment are critical to activate dendritic cells (DCs), components of the innate immune system that shape both innate and adaptive immunity. However, to prevent inappropriate immune activation, mechanisms must be in place to restrain DC activation to ensure DCs are activated only once sufficient stimuli have been received. Here, we report that DC activation and immunogenicity are regulated by the transcriptional repressor Polycomb group factor 6 (PCGF6). Pcgf6 is rapidly downregulated upon stimulation, and this downregulation is necessary to permit full DC activation. Silencing PCGF6 expression enhanced both spontaneous and stimulated DC activation. We show that PCGF6 associates with the H3K4me3 demethylase JARID1c, and together, they negatively regulate H3K4me3 levels in DCs. Our results identify two key regulators, PCGF6 and JARID1c that temper DC activation and implicate active transcriptional silencing via histone demethylation as a previously unappreciated mechanism for regulating DC activation and quiescence.

  2. Quiescence of Memory CD8(+) T Cells Is Mediated by Regulatory T Cells through Inhibitory Receptor CTLA-4.

    PubMed

    Kalia, Vandana; Penny, Laura Anne; Yuzefpolskiy, Yevgeniy; Baumann, Florian Martin; Sarkar, Surojit

    2015-06-16

    Immune memory cells are poised to rapidly expand and elaborate effector functions upon reinfection yet exist in a functionally quiescent state. The paradigm is that memory T cells remain inactive due to lack of T cell receptor (TCR) stimuli. Here, we report that regulatory T (Treg) cells orchestrate memory T cell quiescence by suppressing effector and proliferation programs through inhibitory receptor, cytotoxic-T-lymphocyte-associated protein-4 (CTLA-4). Loss of Treg cells resulted in activation of genome-wide transcriptional programs characteristic of effector T cells and drove transitioning as well as established memory CD8(+) T cells toward terminally differentiated KLRG-1(hi)IL-7Rα(lo)GzmB(hi) phenotype, with compromised metabolic fitness, longevity, polyfunctionality, and protective efficacy. CTLA-4 functionally replaced Treg cells in trans to rescue memory T cell defects and restore homeostasis. These studies present the CTLA-4-CD28-CD80/CD86 axis as a potential target to accelerate vaccine-induced immunity and improve T cell memory quality in current cancer immunotherapies proposing transient Treg cell ablation.

  3. Quiescence of Asian dust events in South Korea and Japan during 2012 spring: Dust outbreaks and transports

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Ho, Chang-Hoi; Kim, Joo-Hong; Kim, Jhoon

    2015-08-01

    This study examined the quiescence of Asian dust events in South Korea and Japan during the spring of 2012, presenting a synoptic characterization and suggesting possible causes. Synoptic observation reports from the two countries confirmed that spring 2012 had the lowest number of dust events in 2000-2012. The monthly dust frequency (DF) in March 2012 over the dust source regions, i.e., deserts in northern China and Mongolia, indicated a significant decrease compared to the 12 year (2000-2011) March climatology. The DF in April 2012 was comparable to the 12 year climatology values, but in May 2012 it was slightly lower. The daily Ozone Monitoring Instrument Aerosol Index and the Navy Aerosol Analysis and Prediction System simulations revealed stagnant dust movement in March and May 2012. Anomalous anticyclones north of the source regions decreased the dust outbreaks and enhanced the southeasterly winds, resulting in few dust events over the downwind countries (i.e., South Korea and Japan). By contrast, in April 2012, a strong anomalous cyclone east of Lake Baikal slightly increased the dust outbreaks over northeastern China. However, the major dust outbreaks were not transported downwind because of exceptional dust pathways, i.e., the southeastward pathway of dust transport was unusually blocked by the expansion of an anomalous anticyclonic circulation over the Sea of Okhotsk, with dust being transported northeast.

  4. Evidence for 830 years of seismic quiescence from palaeoseismology, archaeoseismology and historical seismicity along the Dead Sea fault in Syria

    NASA Astrophysics Data System (ADS)

    Meghraoui, Mustapha; Gomez, Francisco; Sbeinati, Reda; Van der Woerd, Jerome; Mouty, Michel; Darkal, Abdul Nasser; Radwan, Youssef; Layyous, Ihsan; Al Najjar, Haithem; Darawcheh, Ryad; Hijazi, Fouad; Al-Ghazzi, Riad; Barazangi, Muawia

    2003-05-01

    The long historical record of earthquakes, the physical effects on ancient building structures and the palaeoseismology provide a unique opportunity for an interdisciplinary tectonic analysis along a major plate boundary and a realistic evaluation of the seismic hazard assessment in the Middle East. We demonstrate with micro-topographic surveys and trenching that the Dead Sea fault (DSF) offsets left-laterally by 13.6±0.2 m a repeatedly fractured ancient Roman aqueduct (older than AD 70 and younger than AD 30). Carbon-14 dating of faulted young alluvial deposits documents the occurrence of three large earthquakes in the past 2000 years between AD 100 and 750, between AD 700 and 1030 and between AD 990 and 1210. Our study provides the timing of late Holocene earthquakes and constrains the 6.9±0.1 mm/yr slip rate of the Dead Sea transform fault in northwestern Syria along the Missyaf segment. The antepenultimate and most recent faulting events may be correlated with the AD 115 and AD 1170 large earthquakes for which we estimate Mw=7.3-7.5. The ˜830 yr of seismic quiescence along the Missyaf fault segment implies that a large earthquake is overdue and may result in a major catastrophe to the population centres of Syria and Lebanon.

  5. Hematopoietic stem cells lacking Ott1 display aspects associated with aging and are unable to maintain quiescence during proliferative stress

    PubMed Central

    Xiao, Nan; Jani, Kaushal; Morgan, Kelly; Okabe, Rachel; Cullen, Dana E.; Jesneck, Jonathan L.

    2012-01-01

    Aging degrades hematopoietic stem cell (HSC) functions, including stress response; however, the involved molecular pathways are incompletely defined. Murine BM conditionally deleted for One-Twenty-Two-1 (Ott1), is able to maintain lifelong hematopoiesis and has preserved numbers of long-term HSCs, yet cannot repopulate nor sustain itself after transplantation against a competitor even when Ott1 is excised after engraftment. We show, specifically under replicative stress, that Ott1-deleted HSCs have a significant reduction of the G0 cell-cycle fraction associated with self-renewal and undergo early failure. Therefore, Ott1 is required to preserve HSC quiescence during stress but not steady-state hematopoiesis. Reduced tolerance of replicative stress, increased myeloid potential, and greater absolute numbers are mutual characteristics of both Ott1-deleted and aged HSCs, and comparison of their gene expression profiles reveals a shared signature. Ott1-deleted HSCs share multiple aging-associated physiologic changes, including increases in NF-κB activation and DNA damage. Loss of Ott1 causes increased reactive oxygen species; however, antioxidant treatment does not rescue the competitive defect, indicating the existence of additional essential Ott1-dependent HSC pathways. In conclusion, our data establish a requirement for Ott1 in stress hematopoiesis and suggest that Ott1-dependent processes may converge with those affected by aging. PMID:22490678

  6. Further X-ray observations of EXO 0748-676 in quiescence: evidence for a cooling neutron star crust

    NASA Astrophysics Data System (ADS)

    Degenaar, N.; Wolff, M. T.; Ray, P. S.; Wood, K. S.; Homan, J.; Lewin, W. H. G.; Jonker, P. G.; Cackett, E. M.; Miller, J. M.; Brown, E. F.; Wijnands, R.

    2011-04-01

    In late 2008, the quasi-persistent neutron star X-ray transient and eclipsing binary EXO 0748-676 started a transition from outburst to quiescence, after it actively accreted for more than 24 yr. In a previous work, we discussed Chandra and Swift observations obtained during the first 5 months of this transition. Here, we report on further X-ray observations of EXO 0748-676, extending the quiescent monitoring to 1.6 yr. Chandra and XMM-Newton data reveal quiescent X-ray spectra composed of a soft, thermal component that is well fitted by a neutron star atmosphere model. An additional hard power-law tail is detected that changes non-monotonically over time, contributing between 4 and 20 per cent to the total unabsorbed 0.5-10 keV flux. The combined set of Chandra, XMM-Newton and Swift data reveals that the thermal bolometric luminosity fades from ˜ 1 × 1034 to 6 × 1033 (D/7.4 kpc)2 erg s -1, whereas the inferred neutron star effective temperature decreases from ˜124 to 109 eV. We interpret the observed decay as cooling of the neutron star crust and show that the fractional quiescent temperature change of EXO 0748-676 is markedly smaller than observed for three other neutron star X-ray binaries that underwent prolonged accretion outbursts.

  7. Impaired coenzyme A synthesis in fission yeast causes defective mitosis, quiescence-exit failure, histone hypoacetylation and fragile DNA

    PubMed Central

    Nakamura, Takahiro; Pluskal, Tomáš; Nakaseko, Yukinobu; Yanagida, Mitsuhiro

    2012-01-01

    Biosynthesis of coenzyme A (CoA) requires a five-step process using pantothenate and cysteine in the fission yeast Schizosaccharomyces pombe. CoA contains a thiol (SH) group, which reacts with carboxylic acid to form thioesters, giving rise to acyl-activated CoAs such as acetyl-CoA. Acetyl-CoA is essential for energy metabolism and protein acetylation, and, in higher eukaryotes, for the production of neurotransmitters. We isolated a novel S. pombe temperature-sensitive strain ppc1-537 mutated in the catalytic region of phosphopantothenoylcysteine synthetase (designated Ppc1), which is essential for CoA synthesis. The mutant becomes auxotrophic to pantothenate at permissive temperature, displaying greatly decreased levels of CoA, acetyl-CoA and histone acetylation. Moreover, ppc1-537 mutant cells failed to restore proliferation from quiescence. Ppc1 is thus the product of a super-housekeeping gene. The ppc1-537 mutant showed combined synthetic lethal defects with five of six histone deacetylase mutants, whereas sir2 deletion exceptionally rescued the ppc1-537 phenotype. In synchronous cultures, ppc1-537 cells can proceed to the S phase, but lose viability during mitosis failing in sister centromere/kinetochore segregation and nuclear division. Additionally, double-strand break repair is defective in the ppc1-537 mutant, producing fragile broken DNA, probably owing to diminished histone acetylation. The CoA-supported metabolism thus controls the state of chromosome DNA. PMID:23091701

  8. The Transcriptional Repressor Polycomb Group Factor 6, PCGF6, Negatively Regulates Dendritic Cell Activation and Promotes Quiescence.

    PubMed

    Boukhaled, Giselle M; Cordeiro, Brendan; Deblois, Genevieve; Dimitrov, Vassil; Bailey, Swneke D; Holowka, Thomas; Domi, Anisa; Guak, Hannah; Chiu, Huai-Hsuan Clare; Everts, Bart; Pearce, Edward J; Lupien, Mathieu; White, John H; Krawczyk, Connie M

    2016-08-16

    Pro-inflammatory signals provided by the microenvironment are critical to activate dendritic cells (DCs), components of the innate immune system that shape both innate and adaptive immunity. However, to prevent inappropriate immune activation, mechanisms must be in place to restrain DC activation to ensure DCs are activated only once sufficient stimuli have been received. Here, we report that DC activation and immunogenicity are regulated by the transcriptional repressor Polycomb group factor 6 (PCGF6). Pcgf6 is rapidly downregulated upon stimulation, and this downregulation is necessary to permit full DC activation. Silencing PCGF6 expression enhanced both spontaneous and stimulated DC activation. We show that PCGF6 associates with the H3K4me3 demethylase JARID1c, and together, they negatively regulate H3K4me3 levels in DCs. Our results identify two key regulators, PCGF6 and JARID1c that temper DC activation and implicate active transcriptional silencing via histone demethylation as a previously unappreciated mechanism for regulating DC activation and quiescence. PMID:27498878

  9. Did a Stress Change due to a Long-Term Slow Slip Event in the Tokai Region Cause Distant Seismic Quiescence in the Tamba Region, Japan?

    NASA Astrophysics Data System (ADS)

    Sugaya, K.; Hiramatsu, Y.; Furumoto, M.; Katao, H.

    2008-12-01

    Seismic quiescence is useful information for the earthquake prediction. Relationships between seismicity rate change and stressing rate change have been reported by theoretical and observational studies (Dieterich, 1994; Toda et al., 2002). Recently, Ogata (2007) showed that a silent slip event might occur within the source region of an intraplate earthquake preceding the rupture from seismicity rate changes and GPS anomalies. The Tamba region in southwest Japan is located to the northeast of the rupture zone of the 1995 Hyogo-ken Nanbu Earthquake (Mjma 7.3). In the region, the seismicity was activated by a coseismic static stress change (+20kPa; Hiramatsu et al., 2000) due to the event. A distinct decrease in seismicity rate of microearthquakes was recognized in 2003 (Katao, 2005). Such a seismic quiescence had continued for two and a half years before the event (DPRI, 1999). It has, therefore, been controversial whether a major earthquake follows the quiescence or not (e.g., Umeda et al., 2005). We showed that the Tamba region was located in a region where Δ CFS decreased (-0.5kPa/yr) due to the long-term slow slip event (SSE) in the Tokai region and indicated that the beginning of the quiescence seemed to be associated with that of the event (Sugaya et al., 2007IUGG). Our purpose in this study is to investigate whether the quiescence in the Tamba region is caused by the stress change due to the long-term SSE or not based on the rate- and state- friction law (Dieterich, 1994). We use the hypocentral catalog of the DPRI from 1987 to 2001 and that relocated in this study from 2002 to 2006. We use declustered earthquakes (Reasenberg, 1985) greater than or equal to M 2.5 for following analyses. We find that the seismicity in the Tamba region after the 1995 Hyogo-ken Nanbu earthquake is explained by the Omori"fs law (p=1) than the ETAS model (Ogata, 1986). The seismicity is, thus, interpreted as the aftershock-type activity of the earthquake. We estimate Aσ (A is

  10. Evaluation of Temperament and Character Features as Risk Factors for Depressive Symptoms in Patients with Restless Legs Syndrome

    PubMed Central

    Gazioglu, Sibel; Can Usta, Nuray; Ozkorumak, Evrim; Ayar, Ahmet; Topbas, Murat; Boz, Cavit

    2014-01-01

    Background and Purpose Restless legs syndrome (RLS) is a common sleep-related movement disorder that is frequently associated with psychological disturbances. Personality traits are of considerable importance with respect to coping with chronic illness and disease vulnerability. This study assessed the temperament and character traits of RLS patients using an approach that involves the psychobiological model of personality. Methods The personality features of 65 newly diagnosed and untreated RLS patients with no neurological or psychiatric diseases and 109 healthy controls were determined using the Temperament and Character Inventory and compared using covariance analyses. The International RLS Study Group Severity Scale was used to assess the severity of the RLS symptoms, and the Beck Depression Inventory was used to assess the presence and severity of depressive symptoms. Results RLS patients scored significantly higher than healthy controls on the temperament dimension of harm avoidance (HA, p=0.02) and significantly lower on self-directedness (SD, p=0.001). No significant difference was observed in terms of the temperament dimension of novelty seeking (p=0.435). HA scores were significantly correlated with the BDI score but not with the RLS severity or duration. Conclusions High HA and low SD scores are the main characterizing personality features of RLS patients. These personality dimensions may be among the factors predisposing patients to development of the depressive symptoms that are frequently associated with RLS. PMID:25324881

  11. Zolpidem Induced Sleep-related Eating and Complex Behaviors in a Patient with Obstructive Sleep Apnea and Restless Legs Syndrome

    PubMed Central

    Park, Young-Min; Shin, Hyun-Woo

    2016-01-01

    Zolpidem-induced sleep-related complex behaviors (SRCB) with anterograde amnesia have been reported. We describe herein a case in which the development of zolpidem-induced sleep-related eating disorder (SRED) and SRCB was strongly suspected. A 71-year-old Korean male was admitted to the Department of Psychiatry due to his repetitive SRED and SRCB with anterograde amnesia, which he reported as having occurred since taking zolpidem. The patient also had restless legs syndrome (RLS) and obstructive sleep apnea (OSA). His baseline serum iron level was low at admission. Zolpidem discontinuation resulted in the immediate disappearance of his SRED, but did not affect his RLS symptoms. These symptoms rapidly improved after adding a single i.v. iron injection once daily, and so he was discharged to day-clinic treatment. These findings indicate that zolpidem can induce SRCB. Although the pathophysiology of zolpidem-induced SRED and other SRCB remains unclear, clinicians should carefully monitor for the potential induction of complex behaviors associated with zolpidem in patients with comorbid RLS or OSA. PMID:27489385

  12. Comparative placebo-controlled polysomnographic and psychometric studies on the acute effects of gabapentin versus ropinirole in restless legs syndrome.

    PubMed

    Saletu, Michael; Anderer, Peter; Saletu-Zyhlarz, Gerda Maria; Parapatics, Silvia; Gruber, Georg; Nia, Saba; Saletu, Bernd

    2010-04-01

    The aim of the present placebo-controlled sleep laboratory study was to compare the acute effects of gabapentin (GBT) and ropinirole (ROP) in restless legs syndrome (RLS). In a parallel-group design, 40 RLS patients received 300 mg GBT and another 40 patients 0.5 mg ROP as compared with placebo. Polysomnographic and psychometric measures were obtained in three sleep laboratory nights (screening/placebo/drug). Statistics included a Wilcoxon test for differences between drug and placebo and a U test for inter-group differences. Sleep efficiency and latency were found significantly improved after GBT, while they remained unchanged after ROP, with significant inter-drug differences. Sleep architecture showed oppositional changes after the two drugs: While GBT decreased S1, increased slow-wave sleep and SREM and shortened REM latency, ROP increased S2, decreased slow-wave sleep and SREM and increased REM latency. Periodic leg movements (PLM) showed a significantly greater decrease after ROP (-73%) than after GBT (-35%). Subjective sleep quality improved significantly only after GBT; mental performance improved after both drugs with no inter-drug differences. In conclusion, the dopamine agonist ROP showed acute therapeutic efficacy with regard to PLM measures only, whereas GBT had a less pronounced effect on these measures, but improved objective and subjective sleep and awakening quality as compared with both placebo and ROP. Differential acute drug effects may serve as prognostic indicators of therapeutic response of individual patients.

  13. Zolpidem Induced Sleep-related Eating and Complex Behaviors in a Patient with Obstructive Sleep Apnea and Restless Legs Syndrome.

    PubMed

    Park, Young-Min; Shin, Hyun-Woo

    2016-08-31

    Zolpidem-induced sleep-related complex behaviors (SRCB) with anterograde amnesia have been reported. We describe herein a case in which the development of zolpidem-induced sleep-related eating disorder (SRED) and SRCB was strongly suspected. A 71-year-old Korean male was admitted to the Department of Psychiatry due to his repetitive SRED and SRCB with anterograde amnesia, which he reported as having occurred since taking zolpidem. The patient also had restless legs syndrome (RLS) and obstructive sleep apnea (OSA). His baseline serum iron level was low at admission. Zolpidem discontinuation resulted in the immediate disappearance of his SRED, but did not affect his RLS symptoms. These symptoms rapidly improved after adding a single i.v. iron injection once daily, and so he was discharged to day-clinic treatment. These findings indicate that zolpidem can induce SRCB. Although the pathophysiology of zolpidem-induced SRED and other SRCB remains unclear, clinicians should carefully monitor for the potential induction of complex behaviors associated with zolpidem in patients with comorbid RLS or OSA. PMID:27489385

  14. Alternative treatment of restless legs syndrome: an overview of the evidence for mind-body interventions, lifestyle interventions, and neutraceuticals.

    PubMed

    Bega, Danny; Malkani, Roneil

    2016-01-01

    Conventional pharmacologic treatment of restless legs syndrome (RLS) may be limited in some people. Up to 65% of patients with RLS regularly use alternative practices for symptom relief. We reviewed the current clinical evidence, and we proposed physiologic basis for various alternative practices for RLS including mind-body interventions (conventional exercise, yoga, and acupuncture), non-pharmacologic lifestyle interventions (pneumatic compression devices [PCDs], light therapy, and cognitive-behavioral therapy [CBT]), and neutraceuticals (vitamins, valerian, and Chinese herbs). Based on the available evidence, regular physical activity should be recommended for the treatment of RLS symptoms. Oral iron supplementation should be considered for people with RLS who have low ferritin levels, although criteria to identify probable responders, and optimal formulations and durations of treatment are needed. Supplementation for low levels of vitamins E, C, and D could be considered, although evidence specifically in RLS is limited, and it is unclear if levels should routinely be checked in patients with RLS. Insufficient evidence exists for yoga, acupuncture, PCDs, near-infrared light therapy, CBT, valerian, or Chinese herbs, but preliminary studies on each of these suggest that high-quality randomized controlled trials may be warranted to support and verify the data presented. PMID:26847981

  15. The decrease in histone methyltransferase EZH2 in response to fluid shear stress alters endothelial gene expression and promotes quiescence.

    PubMed

    Maleszewska, Monika; Vanchin, Byambasuren; Harmsen, Martin C; Krenning, Guido

    2016-01-01

    High uniform fluid shear stress (FSS) is atheroprotective and preserves the endothelial phenotype and function through activation of downstream mediators such as MAPK7 (Erk5). Endothelial cells respond to FSS thanks to mechanotransduction. However, how the resulting signaling is integrated and resolved at the epigenetic level remains elusive. We hypothesized that Polycomb methyltransferase EZH2 is involved in the effects of FSS in human endothelial cells. We showed that FSS decreases the expression of the Polycomb methyltransferase EZH2. Despite simultaneous activation of MAPK7, MAPK7 pathway does not directly influence the transcription of EZH2. Interestingly though, the knockdown of EZH2 activates the protective MAPK7 signaling in endothelial cells, even in the absence of FSS. To understand the influence of the FSS-decreased expression of EZH2 on endothelial transcriptome, we performed RNA-seq and differential gene expression analysis. We identified candidate groups of genes dependent on both EZH2 and FSS. Among those, Gene Ontology overrepresentation analysis revealed highly significant enrichment of the cell cycle-related genes, suggesting changes in proliferation. Indeed, the depletion of EZH2 strongly inhibited endothelial proliferation, indicating cell cycle arrest. The concomitant decrease in CCNA expression suggests the transition of endothelial cells into a quiescent phenotype. Further bioinformatical analysis suggested TXNIP as a possible mediator between EZH2 and cell cycle-related gene network. Our data show that EZH2 is a FSS-responsive gene. Decreased EZH2 levels enhance the activation of the atheroprotective MAPK7 signaling. Decrease in EZH2 under FSS mediates the decrease in the expression of the network of cell cycle-related genes, which allows the cells to enter quiescence. EZH2 is therefore important for the protective effects of FSS in endothelium.

  16. Early Low Urinary CXCL9 and CXCL10 Might Predict Immunological Quiescence in Clinically and Histologically Stable Kidney Recipients.

    PubMed

    Rabant, M; Amrouche, L; Morin, L; Bonifay, R; Lebreton, X; Aouni, L; Benon, A; Sauvaget, V; Le Vaillant, L; Aulagnon, F; Sberro, R; Snanoudj, R; Mejean, A; Legendre, C; Terzi, F; Anglicheau, D

    2016-06-01

    We monitored the urinary C-X-C motif chemokine (CXCL)9 and CXCL10 levels in 1722 urine samples from 300 consecutive kidney recipients collected during the first posttransplantation year and assessed their predictive value for subsequent acute rejection (AR). The trajectories of urinary CXCL10 showed an early increase at 1 month (p = 0.0005) and 3 months (p = 0.0009) in patients who subsequently developed AR. At 1 year, the AR-free allograft survival rates were 90% and 54% in patients with CXCL10:creatinine (CXCL10:Cr) levels <2.79 ng/mmoL and >2.79 ng/mmoL at 1 month, respectively (p < 0.0001), and 88% and 56% in patients with CXCL10:Cr levels <5.32 ng/mmoL and >5.32 ng/mmoL at 3 months (p < 0.0001), respectively. CXCL9:Cr levels also associate, albeit less robustly, with AR-free allograft survival. Early CXCL10:Cr levels predicted clinical and subclinical rejection and both T cell- and antibody-mediated rejection. In 222 stable patients, CXCL10:Cr at 3 months predicted AR independent of concomitant protocol biopsy results (p = 0.009). Although its positive predictive value was low, a high negative predictive value suggests that early CXCL10:Cr might predict immunological quiescence on a triple-drug calcineurin inhibitor-based immunosuppressive regimen in the first posttransplantation year, even in clinically and histologically stable patients. The clinical utility of this test will need to be addressed by dedicated prospective clinical trials. PMID:26694099

  17. The First Low-mass Black Hole X-Ray Binary Identified in Quiescence Outside of a Globular Cluster

    NASA Astrophysics Data System (ADS)

    Tetarenko, B. E.; Bahramian, A.; Arnason, R. M.; Miller-Jones, J. C. A.; Repetto, S.; Heinke, C. O.; Maccarone, T. J.; Chomiuk, L.; Sivakoff, G. R.; Strader, J.; Kirsten, F.; Vlemmings, W.

    2016-07-01

    The observed relation between the X-ray and radio properties of low-luminosity accreting black holes (BHs) has enabled the identification of multiple candidate black hole X-ray binaries (BHXBs) in globular clusters (GCs). Here, we report an identification of the radio source VLA J213002.08+120904 (aka M15 S2), recently reported in Kirsten et al., as a BHXB candidate. They showed that the parallax of this flat-spectrum variable radio source indicates a {2.2}-0.3+0.5 kpc distance, which identifies it as lying in the foreground of the GC M15. We determine the radio characteristics of this source and place a deep limit on the X-ray luminosity of ˜4 × 1029 erg s-1. Furthermore, we astrometrically identify a faint red stellar counterpart in archival Hubble images with colors consistent with a foreground star; at 2.2 kpc, its inferred mass is 0.1-0.2 M ⊙. We rule out that this object is a pulsar, neutron star X-ray binary, cataclysmic variable, or planetary nebula, concluding that VLA J213002.08+120904 is the first accreting BHXB candidate discovered in quiescence outside of a GC. Given the relatively small area over which parallax studies of radio sources have been performed, this discovery suggests a much larger population of quiescent BHXBs in our Galaxy, 2.6 × 104-1.7 × 108 BHXBs at 3σ confidence, than has been previously estimated (˜102-104) through population synthesis.

  18. Mitochondrial mRNA stability and polyadenylation during anoxia-induced quiescence in the brine shrimp Artemia franciscana.

    PubMed

    Eads, Brian D; Hand, Steven C

    2003-10-01

    Polyadenylation of messenger RNA is known to be an important mechanism for regulating mRNA stability in a variety of systems, including bacteria, chloroplasts and plant mitochondria. By comparison, little is known about the role played by polyadenylation in animal mitochondrial gene expression. We have used embryos of the brine shrimp Artemia franciscana to test hypotheses regarding message stability and polyadenylation under conditions simulating anoxia-induced quiescence. In response to anoxia, these embryos undergo a profound and acute metabolic downregulation, characterized by a steep drop in intracellular pH (pH(i)) and ATP levels. Using dot blots of total mitochondrial RNA, we show that during in organello incubations both O(2) deprivation and acidic pH (pH 6.4) elicit increases in half-lives of selected mitochondrial transcripts on the order of five- to tenfold or more, relative to normoxic controls at pH 7.8. Polyadenylation of these transcripts was measured under the same incubation conditions using a reverse transcriptase-polymerase chain reaction (RT-PCR)-based assay. The results demonstrate that low pH and anoxia promote significant deadenylation of the stabilized transcripts in several cases, measured either as change over time in the amount of polyadenylation within a given size class of poly(A)(+) tail, or as the total amount of polyadenylation at the endpoint of the incubation. This study is the first direct demonstration that for a metazoan mitochondrion, polyadenylation is associated with destabilized mRNA. This pattern has also been demonstrated in bacteria, chloroplasts and plant mitochondria and may indicate a conserved mechanism for regulating message half-life that differs from the paradigm for eukaryotic cytoplasm, where increased mRNA stability is associated with polyadenylation. PMID:12966060

  19. Early Low Urinary CXCL9 and CXCL10 Might Predict Immunological Quiescence in Clinically and Histologically Stable Kidney Recipients.

    PubMed

    Rabant, M; Amrouche, L; Morin, L; Bonifay, R; Lebreton, X; Aouni, L; Benon, A; Sauvaget, V; Le Vaillant, L; Aulagnon, F; Sberro, R; Snanoudj, R; Mejean, A; Legendre, C; Terzi, F; Anglicheau, D

    2016-06-01

    We monitored the urinary C-X-C motif chemokine (CXCL)9 and CXCL10 levels in 1722 urine samples from 300 consecutive kidney recipients collected during the first posttransplantation year and assessed their predictive value for subsequent acute rejection (AR). The trajectories of urinary CXCL10 showed an early increase at 1 month (p = 0.0005) and 3 months (p = 0.0009) in patients who subsequently developed AR. At 1 year, the AR-free allograft survival rates were 90% and 54% in patients with CXCL10:creatinine (CXCL10:Cr) levels <2.79 ng/mmoL and >2.79 ng/mmoL at 1 month, respectively (p < 0.0001), and 88% and 56% in patients with CXCL10:Cr levels <5.32 ng/mmoL and >5.32 ng/mmoL at 3 months (p < 0.0001), respectively. CXCL9:Cr levels also associate, albeit less robustly, with AR-free allograft survival. Early CXCL10:Cr levels predicted clinical and subclinical rejection and both T cell- and antibody-mediated rejection. In 222 stable patients, CXCL10:Cr at 3 months predicted AR independent of concomitant protocol biopsy results (p = 0.009). Although its positive predictive value was low, a high negative predictive value suggests that early CXCL10:Cr might predict immunological quiescence on a triple-drug calcineurin inhibitor-based immunosuppressive regimen in the first posttransplantation year, even in clinically and histologically stable patients. The clinical utility of this test will need to be addressed by dedicated prospective clinical trials.

  20. ON THE EFFECT OF EXPLOSIVE THERMONUCLEAR BURNING ON THE ACCRETED ENVELOPES OF WHITE DWARFS IN CATACLYSMIC VARIABLES

    SciTech Connect

    Sion, Edward M.; Sparks, Warren E-mail: warrensparks@comcast.net

    2014-11-20

    The detection of heavy elements at suprasolar abundances in the atmospheres of some accreting white dwarfs in cataclysmic variables (CVs), coupled with the high temperatures needed to produce these elements, requires explosive thermonuclear burning. The central temperatures of any formerly more massive secondary stars in CVs undergoing hydrostatic CNO burning are far too low to produce these elements. Evidence is presented that at least some CVs contain donor secondaries that have been contaminated by white dwarf remnant burning during the common envelope phase and are transferring this material back to the white dwarf. This scenario does not exclude the channel in which formerly more massive donor stars underwent CNO processing in systems with thermal timescale mass transfer. Implications for the progenitors of CVs are discussed and a new scenario for the white dwarf's accretion-nova-outburst is given.

  1. Transition from Beam-Target to Thermonuclear Fusion in High-Current Deuterium Z-Pinch Simulations.

    PubMed

    Offermann, Dustin T; Welch, Dale R; Rose, Dave V; Thoma, Carsten; Clark, Robert E; Mostrom, Chris B; Schmidt, Andrea E W; Link, Anthony J

    2016-05-13

    Fusion yields from dense, Z-pinch plasmas are known to scale with the drive current, which is favorable for many potential applications. Decades of experimental studies, however, show an unexplained drop in yield for currents above a few mega-ampere (MA). In this work, simulations of DD Z-Pinch plasmas have been performed in 1D and 2D for a constant pinch time and initial radius using the code Lsp, and observations of a shift in scaling are presented. The results show that yields below 3 MA are enhanced relative to pure thermonuclear scaling by beamlike particles accelerated in the Rayleigh-Taylor induced electric fields, while yields above 3 MA are reduced because of energy lost by the instability and the inability of the beamlike ions to enter the pinch region.

  2. Ion species mix measurements in DIII-D and International Thermonuclear Experimental Reactor using ion-ion hybrid layer reflectometry

    SciTech Connect

    Heidbrink, W.W.; Watson, G.W.; Burrell, K.H.

    2004-10-01

    A superheterodyne reflectometer can provide a direct and inexpensive measurement of the concentrations of ion species with different charge to mass ratios. The ion-ion hybrid cutoff frequency is uniquely determined by the cyclotron frequencies and concentrations of the different species. The phase of a {approx}20 MHz wave that travels from a launching antenna on the low-field side of a tokamak, reflects off the cutoff layer, then travels to a receiving antenna provides a direct measure of the species mix. Hydrogen concentrations between 3% and 67% are measured in DIII-D using this technique. In theory, the technique can measure the spatial profile of the tritium concentration in the International Thermonuclear Experimental Reactor. Possible practical difficulties include attenuation of the wave in the evanescent layer near the antenna.

  3. HC-HA/PTX3 Purified From Amniotic Membrane Promotes BMP Signaling in Limbal Niche Cells to Maintain Quiescence of Limbal Epithelial Progenitor/Stem Cells.

    PubMed

    Chen, Szu-Yu; Han, Bo; Zhu, Ying-Ting; Mahabole, Megha; Huang, Jie; Beebe, David C; Tseng, Scheffer C G

    2015-11-01

    To explore how limbal niche cells (LNCs) may control quiescence, self-renewal, and corneal epithelial lineage commitment/differentiation of limbal epithelial progenitor/stem cells (LEPCs), we have established an in vitro sphere assay by reunion between the two cell types in three-dimensional Matrigel. The resultant sphere exhibits inhibition of corneal epithelial lineage commitment/differentiation and marked clonal growth of LEPCs, of which the latter is correlated with activation of canonical Wnt signaling. Herein, we have created a similar reunion assay in immobilized heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3), which is purified from amniotic membrane (AM) and consists of a complex formed by hyaluronic covalently linked to heavy chain 1 of inter-α-inhibitor and noncovalently linked to pentraxin 3. The resultant spheres exhibited similar suppression of corneal epithelial lineage commitment/differentiation but upregulation of quiescence markers including nuclear translocation of Bmi-1, and negligible clonal growth of LEPCs. This outcome was correlated with the suppression of canonical Wnt but activation of noncanonical (Planar cell polarity) Wnt signaling as well as BMP signaling in both LEPCs and LNCs. The activation of BMP signaling in LNCs was pivotal because nuclear translocation of pSmad1/5/8 was prohibited in hLEPCs when reunioned with mLNCs of conditionally deleted Bmpr1a;Acvr1(DCKO) mice. Furthermore, ablation of BMP signaling in LEPCs led to upregulation of cell cycle genes, downregulation of Bmi-1, nuclear exclusion of phosphorylated Bmi-1, and marked promotion of the clonal growth of LEPCs. Hence, HC-HA/PTX3 uniquely upregulates BMP signaling in LNCs which leads to BMP signaling in LEPCs to achieve quiescence, helping explain how AM transplantation is clinically useful to be used as a matrix for ex vivo expansion of LEPCs and to treat corneal blindness caused by limbal stem cells deficiency.

  4. Multiband Studies of the Optical Periodic Modulation in the X-Ray Binary SAX J1808.4-3658 during Its Quiescence and 2008 Outburst

    NASA Astrophysics Data System (ADS)

    Wang, Zhongxiang; Breton, Rene P.; Heinke, Craig O.; Deloye, Christopher J.; Zhong, Jing

    2013-03-01

    We report on time-resolved optical imaging of the X-ray binary SAX J1808.4-3658 during its quiescent state and 2008 outburst. The binary, containing an accretion-powered millisecond pulsar, has a large sinusoidal-like modulation in its quiescent optical emission. We employ a Markov chain Monte Carlo technique to fit our multi-band light curve data in quiescence with an irradiated star model, and derive a tight constraint of 50^{+6}_{-5} deg on the inclination angle i of the binary system. The pulsar and its companion are constrained to have masses of 0.97^{+0.31}_{-0.22} M_{⊙} and 0.04^{+0.02}_{-0.01} M_{⊙} (both 1σ ranges), respectively. The dependence of these results on the measurements of the companion's projected radial velocity is discussed. We also find that the accretion disk had nearly constant optical fluxes over a ~500 day period in the quiescent state our data covered, but started brightening 1.5 months before the 2008 outburst. Variations in modulation during the outburst were detected in our four observations made 7-12 days after the start of the outburst, and a sinusoidal-like modulation with 0.2 mag amplitude changed to have a smaller amplitude of 0.1 mag. The modulation variations are discussed. We estimate the albedo of the companion during its quiescence and the outburst, which was approximately 0 and 0.8 (for isotropic emission), respectively. This large difference probably provides additional evidence that the neutron star in the binary turns on as a radio pulsar in quiescence.

  5. Unusual Patterns of Seismicity during Eruptive and Non-eruptive Periods at the Persistently Restless Telica Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Rodgers, Melanie J.

    Telica Volcano, Nicaragua, is a persistently restless volcano with high rates of seismicity that can vary from less than ten events to over a thousand events per day. Low-frequency (LF) events dominate the seismic catalogue and seismicity rates at Telica show little clear correlation with periods of eruption. As such, traditional methods of forecasting of volcanic activity based on increases in seismicity and recognition of LF activity are not applicable. A single seismic station has been operating at Telica since 1993, and in 2010 we installed a broadband seismic and continuous GPS network (TESAND network) at Telica. In this study we investigate the seismic characteristics surrounding a nine-month period of phreatic to phreatomagmatic explosions in 1999, and also from the initial three-and-a-half year deployment of the TESAND network, including a three-month phreatic vulcanian eruptive period in 2011. We demonstrate that pertinent information can be obtained from analysis of single-station data, and while large seismic networks are preferable when possible, we note that for many volcanoes this is not possible. We find unusual patterns of seismicity before both eruptive periods; rather than a precursory increase in seismicity as is observed prior to many volcanic eruptions, we observe a decrease in seismicity many months prior to eruption. We developed a new program for cross-correlation of large seismic data catalogues and analysed multiplet activity surrounding both eruptive periods. We observed that the formation of new multiplets corresponds to periods of high event rates (during inter-eruptive periods) and high percentages of daily events that belong to a multiplet. We propose a model for the seismicity patterns observed at Telica, where changes in seismicity are related to a cyclic transition between open-system degassing and closed-system degassing. Periods of open-system degassing occur during non-eruptive episodes and are characterised by high event rates

  6. Physical Activity and Self-reported Symptoms of Insomnia, Restless Legs Syndrome and Depression: the Comprehensive Dialysis Study

    PubMed Central

    Anand, Shuchi; Johansen, Kirsten L.; Grimes, Barbara; Kaysen, George A.; Dalrymple, Lorien S.; Kutner, Nancy G.; Chertow, Glenn M.

    2012-01-01

    Background Symptoms of sleep and mood disturbances are common among patients on dialysis and are associated with significant decrements in survival and health-related quality of life. We used data from the Comprehensive Dialysis Study (CDS) to examine the association of self-reported physical activity with self-reported symptoms of insomnia, restless legs syndrome (RLS) and depression in patients new to dialysis. Methods The CDS collected data on physical activity, functional status, and health-related quality of life from 1678 patients on either peritoneal (n=169) or hemodialysis (n=1509). The Human Activity Profile was used to measure self-reported physical activity. Symptoms were elicited in the following manner: insomnia using three questions designed to capture difficulty in initiating or maintaining sleep, RLS using three questions based on the National Institutes of Health workshop, and depression using the 2-item Patient Health Questionnaire. Results We obtained data on symptoms of insomnia and depression for 1636, and on symptoms of RLS for 1622 (>98%) patients. Of these, 863 (53%) reported one of three insomnia symptoms as occurring at a persistent frequency. Symptoms of RLS and depression occurred in 477 (29%) and 451 (28%) of patients, respectively. The Adjusted Activity Score of the Human Activity Profile was inversely correlated with all three conditions in models adjusting for demographics, comorbid conditions, and laboratory variables. Conclusion Sleep and mood disturbances were commonly reported in our large, diverse cohort of patients new to dialysis. Patients who reported lower levels of physical activity were more likely to report symptoms of insomnia, RLS and depression. PMID:22812496

  7. Increased Risk of Restless Legs Syndrome in Patients With Migraine: A Nationwide Population-Based Cohort Study.

    PubMed

    Yang, Fu-Chi; Lin, Te-Yu; Chen, Hsuan-Ju; Lee, Jiunn-Tay; Lin, Chun-Chieh; Huang, Wen-Yen; Chen, Hsin-Hung; Kao, Chia-Hung

    2016-02-01

    Previous studies suggest that an association between restless legs syndrome (RLS) and migraine exists. However, population-based data are unavailable in Asian cohorts. Our study thus aims to evaluate the association between migraine and RLS in a nationwide, population-based cohort in Taiwan and to examine the effects of age, sex, migraine subtype, and comorbidities on RLS development.Data from the Taiwan National Health Insurance Research Database were used. Patients aged 20 years or older with newly diagnosed migraine from 2000 to 2008 were included; 23,641 patients with newly diagnosed migraine and 94,564 subjects without migraine were randomly selected and followed until RLS development, withdrawal from the National Health Insurance, or until the end of 2011. A multivariate Cox proportional hazards regression model was used to explore the risk of RLS in patients with migraine after adjustment for demographic characteristics and comorbidities.Both cohorts were followed for a mean of 7.38 years. After adjustment for covariates, the risk of RLS was 1.42-fold higher (95% confidence interval = 1.13-1.79) in the migraine cohort than in the nonmigraine cohort (7.19 versus 3.42 years per 10,000 person-years). The increased risk was more prominent in males in the migraine cohort (1.87-fold increased risk, 95% confidence interval 1.22-2.85). Neither comorbidity status nor migraine subtype influenced the RLS risk.This population-based study demonstrated that migraine is associated with an increased risk of RLS compared with those without migraine, particularly in male patients with migraine and regardless of the comorbidity status.

  8. Association between the neutrophil-to-lymphocyte ratio, a new marker of systemic inflammation, and restless legs syndrome

    PubMed Central

    Varım, Ceyhun; Acar, Bilgehan Atılgan; Uyanık, Mehmet Sevki; Acar, Turkan; Alagoz, Neslihan; Nalbant, Ahmet; Kaya, Tezcan; Ergenc, Hasan

    2016-01-01

    INTRODUCTION Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is characterised by abnormal sensations in the legs as well as dysaesthesia. Although the aetiology of RLS has not yet been determined, it may be associated with systemic inflammation. The neutrophil-to-lymphocyte ratio (NLR) is a new and simple marker indicating systemic inflammation. The present study aimed to investigate the relationship between systemic inflammation and RLS through the use of the NLR. METHODS A total of 75 newly diagnosed patients with RLS and 56 healthy control subjects were included in the study. Baseline NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. The NLRs of the two groups were compared. RESULTS There were no significant differences in gender and age between the two groups. The NLR was 1.96 ± 0.66 in the patient group and 1.67 ± 0.68 in the control group (p = 0.005). Receiver operating characteristic analysis was performed to determine the cut-off value of NLR to predict RLS. The NLR was predictive at 1.58 with a 64% sensitivity and 50% specificity (95% confidence interval 0.55–0.74, area under curve 0.648 ± 0.05). The NLR was found to be statistically higher in patients with RLS and may be used to predict RLS. CONCLUSION The aetiology of RLS remains undetermined. The present study showed that systemic inflammation may play a role in RLS. However, RLS could also be associated with systemic inflammatory diseases. This relationship is supported by high NLR values, which are related to chronic systemic inflammation. PMID:27662970

  9. A Panchromatic View of the Restless SN 2009ip Reveals the Explosive Ejection of a Massive Star Envelope

    NASA Astrophysics Data System (ADS)

    Margutti, R.; Milisavljevic, D.; Soderberg, A. M.; Chornock, R.; Zauderer, B. A.; Murase, K.; Guidorzi, C.; Sanders, N. E.; Kuin, P.; Fransson, C.; Levesque, E. M.; Chandra, P.; Berger, E.; Bianco, F. B.; Brown, P. J.; Challis, P.; Chatzopoulos, E.; Cheung, C. C.; Choi, C.; Chomiuk, L.; Chugai, N.; Contreras, C.; Drout, M. R.; Fesen, R.; Foley, R. J.; Fong, W.; Friedman, A. S.; Gall, C.; Gehrels, N.; Hjorth, J.; Hsiao, E.; Kirshner, R.; Im, M.; Leloudas, G.; Lunnan, R.; Marion, G. H.; Martin, J.; Morrell, N.; Neugent, K. F.; Omodei, N.; Phillips, M. M.; Rest, A.; Silverman, J. M.; Strader, J.; Stritzinger, M. D.; Szalai, T.; Utterback, N. B.; Vinko, J.; Wheeler, J. C.; Arnett, D.; Campana, S.; Chevalier, R.; Ginsburg, A.; Kamble, A.; Roming, P. W. A.; Pritchard, T.; Stringfellow, G.

    2014-01-01

    The double explosion of SN 2009ip in 2012 raises questions about our understanding of the late stages of massive star evolution. Here we present a comprehensive study of SN 2009ip during its remarkable rebrightenings. High-cadence photometric and spectroscopic observations from the GeV to the radio band obtained from a variety of ground-based and space facilities (including the Very Large Array, Swift, Fermi, Hubble Space Telescope, and XMM) constrain SN 2009ip to be a low energy (E ~ 1050 erg for an ejecta mass ~0.5 M ⊙) and asymmetric explosion in a complex medium shaped by multiple eruptions of the restless progenitor star. Most of the energy is radiated as a result of the shock breaking out through a dense shell of material located at ~5 × 1014 cm with M ~ 0.1 M ⊙, ejected by the precursor outburst ~40 days before the major explosion. We interpret the NIR excess of emission as signature of material located further out, the origin of which has to be connected with documented mass-loss episodes in the previous years. Our modeling predicts bright neutrino emission associated with the shock break-out if the cosmic-ray energy is comparable to the radiated energy. We connect this phenomenology with the explosive ejection of the outer layers of the massive progenitor star, which later interacted with material deposited in the surroundings by previous eruptions. Future observations will reveal if the massive luminous progenitor star survived. Irrespective of whether the explosion was terminal, SN 2009ip brought to light the existence of new channels for sustained episodic mass loss, the physical origin of which has yet to be identified.

  10. Acute placebo-controlled sleep laboratory studies and clinical follow-up with pramipexole in restless legs syndrome.

    PubMed

    Saletu, M; Anderer, P; Saletu-Zyhlarz, G; Hauer, C; Saletu, B

    2002-08-01

    In a single-blind, placebo-controlled crossover trial, the acute efficacy of the dopamine agonist pramipexole was investigated in 11 restless legs syndrome (RLS) patients by sleep laboratory methods, with a clinical follow-up for 4 weeks. In 3 nights (pre-treatment, placebo and drug night), objective sleep quality was determined by polysomnography (PSG), subjective sleep and awakening quality by rating scales, objective awakening quality by psychometry. Clinical follow-up consisted of completion of the International RLS Study Group (IRLSSG) Scale, Zung Depression (SDS) and Anxiety (SAS) Scale, Quality of Life Index, Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale. Concerning acute effects, an omnibus significance test for PSG variables demonstrated a global difference between placebo and pramipexole, but none between pre-treatment and placebo. Pramipexole 0.27 mg significantly decreased the target variable periodic leg movements (PLM)/h of sleep as well as all other RLS/PLM variables and improved objective sleep efficiency and subjective sleep quality as compared with placebo. In sleep architecture, sleep stages S1 and S2 and stage shifts increased, while slow-wave sleep and SREM decreased. After 4 weeks of therapy, the total scores of the IRLSSG questionnaire, sleep quality and daytime sleepiness, depression and quality of life also improved. Thus, acute pramipexole markedly reduced PLM measures and slightly improved objective and subjective sleep quality. Follow-up ratings showed a moderate improvement of RLS and sleep quality, and to a lesser extent of daytime sleepiness, depression and quality of life. The psychopathological findings as well as acute sleep architecture changes are reminiscent of those seen after activating antidepressants.

  11. The effects of a switch-off response accompanied by hypothalamically induced restlessness on immunoendocrinological changes in cats.

    PubMed

    Sumida, Yasuhisa; Kaname, Hitoshi; Mori, Yoshinobu; Kojima, Kyoji; Kubo, Chiharu; Tashiro, Nobutada

    2004-01-01

    Electrical stimulation of the anterior hypothalamus in cats elicits a behavior called restlessness. When a switch is available for the cats to shut off the electrical stimulation, the cats learn to turn off the stimulation (switch-off response; SOR). In this study, we examined the relationship between the SOR and immunoendocrinological alterations. First of all, an escapable stimulation, in which cats could turn off the stimulation, was applied (escapable condition; EC). One month later, inescapable stimulation was delivered under the same conditions except for the fact that the cats could not turn off the stimulation (inescapable condition; IC). A behavioral analysis revealed that unstable patterns of behavior and a reduction in motor activity were observed in IC compared with those in EC. Furthermore, no significant changes in peripheral leukocytes were observed, while plasma epinephrine and cortisol transiently increased after the series of stimulations, but immediately decreased after the end of the stimulation in EC. On the other hand, there was a greater and prolonged increase in the number of peripheral granulocytes and the plasma levels of epinephrine and cortisol from 1 to 2 h after the stimulation until the end of the experiment in IC. Regarding the number of peripheral lymphocytes, CD4+ or CD8+ lymphocytes and the CD4+ to CD8+ ratio, no significant differences were found between EC and IC. These results suggest that the inability to escape from the aversive stimulation caused a decrease in movement and a prolonged alteration of the immune and endocrine systems, as is often observed in learned helplessness.

  12. The Effect of Massage With Lavender Oil on Restless Leg Syndrome in Hemodialysis Patients: A Randomized Controlled Trial

    PubMed Central

    Hashemi, Sayyed Hossein; Hajbagheri, Ali; Aghajani, Mohammad

    2015-01-01

    Background: Restless leg syndrome (RLS) is a common problem in patients with chronic renal failure. It can reduce the quality of life and sleep disturbances. This disorder is usually treated pharmacologically. Recently, complementary medicine methods have been suggested because of chemical drugs adverse effects. There is not enough evidence about the effect of aromatherapy on RLS. Objectives: The aim of this study was to determine the effects of massage with lavender oil on RLS symptoms in hemodialysis patients. Patients and Methods: This randomized clinical trial study included 70 hemodialysis patients with RLS that were randomly assigned into two groups in 2014. The experimental group received effleurage massage using lavender oil and control group received routine care for three weeks. Data was collected with RLS questionnaire and analyzed using independent and paired t-test and Chi-square test. Results: The mean RLS scores were not significantly different in the two groups at the start of study (22.41 ± 7.67 vs. 22.90 ± 4.38, P = 0.76). At the end of study, the mean RLS score significantly decreased in the intervention group, while this score remained relatively un-changed in the control group (12.41 ± 5.49 vs. 23.23 ± 4.52, P < 0.0001). Conclusions: Lavender oil massage was effective to improve RLS in hemodialysis patients. It has no adverse effects, is practical and cost-effective. It is suggested to be used along with routine treatment of RLS in hemodialysis patients. PMID:26835466

  13. “The Marshall Rosenbluth International Summer School – 2007: Plasma Thermonuclear Fusion and Plasma Astrophysics – 2007”

    SciTech Connect

    Stefan, Vladislav Alexander

    2007-10-01

    Contents: H. Berk: Frequency Sweeping Due to Phase Space Structure Formation in Plasmas M. Campbell : The Legacy of Marshall Rosenbluth in the Development of the Laser Fusion Program in the United States J. Candy: Gyrokinetic Simulations of Fusion Plasmas P. Diamond: The Legacy of Marshall Rosenbluth in Magnetic Confinement Theory G-Y. Fu: Nonlinear Hybrid Simulations of Multiple Energetic Particle Driven Alfven Modes in Toroidal Plasmas O. Gurcan: Theory of Intrinsic Rotation and Momentum Transport V. L. Jacobs: Kinetic and Spectral Descriptions for Atomic Processes in Astrophysical and Laboratory Plasmas C. F. Kennel: Marshall Rosenbluth and Roald Sagdeev in Trieste:The Birth of Modern Space Plasma N. A. Krall: The Contribution of Marshall Rosenbluth in the Development of Plasma Drift Wave and Universal Instability Theories C. S. Liu: The Legacy of Marshall Rosenbluth in Laser-Plasma Interaction Research N. Rostoker: Plasma Physics Research With Marshall Rosenbluth - My Teacher R. Z. Sagdeev: The Legacy of Marshall Rosenbluth in Plasma Physics V. Alexander Stefan A Note on the Rosenbluth Paper: Phys. Rev. Letters, 29, 565 (1972), and the Research in Parametric Plasma Theory Thereupon J. W. Van Dam: The Role of Marshall Rosenbluth in the Development of the Thermonuclear Fusion Program in the U.S.A. E. P. Velikhov: Problems in Plasma Astrophysics R. White: The Role of Marshall Rosenbluth in the Development of the Particle and MHD Interaction in Plasmas X. Xu: Edge Gyrokinetic Theory and Continuum Simulations Marshall Nicholas ROSENBLUTH (A Brief Biography) b. February 5,1927 - Albany, New York. d. September 28, 2003 - San Diego, California. M. N. Rosenbluth, a world-acclaimed scientist, is one of the ultimate authorities in plasma and thermonuclear fusion research, often indicated by the sobriquet the "Pope of Plasma Physics." His theoretical contributions have been central to the development of controlled thermonuclear fusion. In the 1950s his pioneering work in

  14. Association Between Vitamin D Receptor rs731236 (Taq1) Polymorphism and Risk for Restless Legs Syndrome in the Spanish Caucasian Population

    PubMed Central

    Jiménez-Jiménez, Félix Javier; García-Martín, Elena; Alonso-Navarro, Hortensia; Martínez, Carmen; Zurdo, Martín; Turpín-Fenoll, Laura; Millán-Pascual, Jorge; Adeva-Bartolomé, Teresa; Cubo, Esther; Navacerrada, Francisco; Rojo-Sebastián, Ana; Rubio, Lluisa; Ortega-Cubero, Sara; Pastor, Pau; Calleja, Marisol; Plaza-Nieto, José Francisco; Pilo-De-La-Fuente, Belén; Arroyo-Solera, Margarita; García-Albea, Esteban; Agúndez, José A.G.

    2015-01-01

    Abstract Several recent works suggest a possible role of vitamin D deficiency in the etiology or restless legs syndrome (RLS). We analyzed the possible relationship of 2 common single nucleotide polymorphisms (SNPs) in the vitamin D3 receptor (VDR) gene with the risk for RLS. We studied the genotype and allelic variant frequencies of VDR rs2228570 and VDR rs731236 SNPs in 205 RLS patients and 445 healthy controls using a TaqMan essay. The frequencies of the rs731236AA genotype and the allelic variant rs731236A were significantly lower in RLS patients than in controls (P < 0.005 and < 0.01, respectively). Restless legs syndrome patients carrying the allelic variant rs731236G had an earlier age at onset, and those carrying the rs731236GG genotype had higher severity of RLS, although these data disappeared after multivariate analyses. None of the SNPs studied was related with the positivity of family history of RLS. These results suggest a modest, but significant association between VDR rs731236 SNP and the risk for RLS. PMID:26632733

  15. Numerical models for ground deformation and gravity changes during volcanic unrest: simulating the hydrothermal system dynamics of a restless caldera

    NASA Astrophysics Data System (ADS)

    Coco, A.; Gottsmann, J.; Whitaker, F.; Rust, A.; Currenti, G.; Jasim, A.; Bunney, S.

    2016-04-01

    Ground deformation and gravity changes in restless calderas during periods of unrest can signal an impending eruption and thus must be correctly interpreted for hazard evaluation. It is critical to differentiate variation of geophysical observables related to volume and pressure changes induced by magma migration from shallow hydrothermal activity associated with hot fluids of magmatic origin rising from depth. In this paper we present a numerical model to evaluate the thermo-poroelastic response of the hydrothermal system in a caldera setting by simulating pore pressure and thermal expansion associated with deep injection of hot fluids (water and carbon dioxide). Hydrothermal fluid circulation is simulated using TOUGH2, a multicomponent multiphase simulator of fluid flows in porous media. Changes in pore pressure and temperature are then evaluated and fed into a thermo-poroelastic model (one-way coupling), which is based on a finite-difference numerical method designed for axi-symmetric problems in unbounded domains.

    Informed by constraints available for the Campi Flegrei caldera (Italy), a series of simulations assess the influence of fluid injection rates and mechanical properties on the hydrothermal system, uplift and gravity. Heterogeneities in hydrological and mechanical properties associated with the presence of ring faults are a key determinant of the fluid flow pattern and consequently the geophysical observables. Peaks (in absolute value) of uplift and gravity change profiles computed at the ground surface are located close to injection points (namely at the centre of the model and fault areas). Temporal evolution of the ground deformation indicates that the contribution of thermal effects to the total uplift is almost negligible with respect to the pore pressure contribution during the first years of the unrest, but increases in time and becomes dominant after a long period of the simulation. After a transient increase over the first years of

  16. Erratum: Optical Observations of GRO J1655-40 in Quiescence. I. A Precise Mass for the Black Hole Primary

    NASA Astrophysics Data System (ADS)

    Orosz, Jerome A.; Bailyn, Charles D.

    1997-06-01

    In the paper ``Optical Observations of GRO J1655-40 in Quiescence. I. A Precise Mass for the Black Hole Primary'' by Jerome A. Orosz and Charles D. Bailyn (ApJ, 477, 876 [1997]), some typographical errors occurred in the main text and in the Appendix that describes the eclipsing light curve code. The legend to Figure 1 should read ``open circles'' instead of ``open diamonds.'' In § A1, the definitions of the angles φ and θ are reversed: the angle φ is the colatitude, and the angle θ is the longitude. Equation (A4) should read g(x, y, z)=[(∂Ψ/∂x)2+(∂Ψ/∂y)2+(∂Ψ/∂z)2]1/2 . (A4) The equation giving the element of surface area dS(x, y, z) (eq. [A9]), while correct, contains some unclear notation. The grid spacings in the coordinate φ are equally spaced in cos φ so that Δφ = | d(cos φ) | = sin φdφ. Thus dS(x, y, z) has the correct form, and the numerical integration over the surface converges. Equation (A10) should read σ(x, y, z)=1/g(x, y, z) [lx ∂Ψ(x, y, z)/∂x+ly ∂Ψ(x, y, z)/∂y+lz ∂Ψ(x, y, z)/∂z] . (A10) Equation (A20) should read d(x, y, z)=(1+R2-2Rlx)1/2 . (A20)There are also two minor changes in the code that need to be made: An approximation was used to compute the foreshortening factor ΓX-ray(x, y, z) (eq. [A21]). The exact expression is ΓX-ray(x, y, z)=-1/d(x, y, z)g(x, y, z) [(x-1)(∂Ψ/∂x)+y(∂Ψ/∂y)+z(∂Ψ/∂z)] . (A21) Equation (A24) should read Φ(x, y, z)=arctan(z cos η/1-x) . (A24) The angle η was incorrectly defined in the code as arctan(y/x). The correct definition should be η = arctan[y/(1 - x)]. The changes in equations (A21) and (A24) alter the model light curves only for cases in which the X-ray luminosity LX is not zero. The most complete light curves were from 1966 March, and we adopted LX = 0 based on the low X-ray flux observed by ASCA during that time. Therefore, the important geometrical parameters that were derived from the modeling of the 1996 light curves are unchanged. For the model

  17. X-Ray Reflection of Thermonuclear Bursts from Neutron Stars: Constraining Flames with RXTE and an Outlook on NICER

    NASA Astrophysics Data System (ADS)

    Keek, Laurens

    2016-04-01

    Thermonuclear X-ray bursts observed from accreting neutron stars are employed to study, e.g., the nuclear physics of rare isotopes and the dense matter equation of state. Recent observations indicate that bursts strongly affect their accretion environment, and reprocessed burst emission may reflect off the inner accretion disk. The spectra of the short (10-100s) bursts are, however, of insufficient quality to accurately separate the neutron star signal from accretion disk emission and burst reflection. Only for two rare "superbursts" with durations of several hours did RXTE/PCA spectra show burst reflection signatures. We discuss the case of 4U 1636-536, where the reflection signal traced the evolution of the ionization state of the inner disk. Our simulations show that a large reflection fraction may indicate that the disk puffs up due to burst irradiation. After separating the direct burst emission from reflection, we show that the rise of the superburst light curve is shaped by a stalling carbon flame. In the near future, the Neutron Star Interior Composition ExploreR (NICER) will have a band-pass that extends below 2 keV, where reflection dominates the burst spectrum, and which was not probed by RXTE. Therefore, NICER will be able to detect reflection features during the frequent short bursts. NICER will open a new field of studying the interaction of bursts and the accretion environment, which will inform us of which bursts are optimally suited for neutron star mass-radius measurements.

  18. Mechanical tests of the conduit tubes of a conductor for the Toroidal winding of the International Thermonuclear Experimental Reactor (ITER)

    NASA Astrophysics Data System (ADS)

    Krivykh, A. V.; Anashkin, O. P.; Keilin, V. E.; Diev, D. N.; Dinisilov, A. S.; Shcherbakov, V. I.; Tronza, V. I.

    2012-11-01

    Extremely stringent requirements, which include the impact toughness at the liquid-helium temperature, are imposed on the material of the conduit tubes for International Thermonuclear Experimental Reactor (ITER) Toroidal Field (TF) conductors. Modified 316LN-IG stainless steel is recommended as the conduit tube material. Steel 316LN-IG tube samples (both full-size samples and sub-sized samples) are subjected to mechanical tests at various stages of the process of conductor production: in the as-recieved state and after compacting, preliminary elongation by 2.5% at room temperature, and annealing at 650°C for 200 h in a pure helium gas atmosphere. The tests are carried out at room, liquid nitrogen, and liquid helium temperatures and satisfy the standards of the American Society of Mechanical Engineers (ASME and ASTM). The results of sub-size and full-size samples testing show that the last one gives more representative results to qualify the weld joints in liquid nitrogen. When the temperature decreases or the strain increases, the magnetization of the samples increases, especially in the weld area. Strain measurements with an extensometer demonstrate that the intracrystal processes occurring at the liquid-helium temperature can lead to a significant change in the local load, up to complete unloading in a deformation zone. Unusual local serrated deformation is observed with an extensometer installed in the weld area during tests in liquid helium: this deformation is the result of compressive jumps opposite to the loading direction.

  19. A hydrodynamic study of a slow nova outburst. [computerized simulation of thermonuclear runaway in white dwarf envelope

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    The paper reports use of a Lagrangian implicit hydrodynamics computer code incorporating a full nuclear-reaction network to follow a thermonuclear runaway in the hydrogen-rich envelope of a 1.25 solar-mass white dwarf. In this evolutionary sequence the envelope was assumed to be of normal (solar) composition and the resulting outburst closely resembles that of the slow nova HR Del. In contrast, previous CNO-enhanced models resemble fast nova outbursts. The slow-nova model ejects material by radiation pressure when the high luminosity of the rekindled hydrogen shell source exceeds the local Eddington luminosity of the outer layers. This is in contrast to the fast nova outburst where ejection is caused by the decay of the beta(+)-unstable nuclei. Nevertheless, radiation pressure probably plays a major role in ejecting material from the fast nova remnants. Therefore, the sequence from slow to fast novae can be interpreted as a sequence of white dwarfs with increasing amounts of enhanced CNO nuclei in their hydrogen envelopes, although other parameters such as the white-dwarf mass and accretion rate probably contribute to the observed variation between novae.

  20. Identification of mRNAs differentially expressed in quiescence or in late G1 phase of the cell cycle in human breast cancer cells by using the differential display method.

    PubMed Central

    Alpan, R. S.; Sparvero, S.; Pardee, A. B.

    1996-01-01

    BACKGROUND: The decision for a cell to enter the DNA synthesis (S) phase of the cell cycle or to arrest in quiescence is likely to be determined by genes expressed in the late G1 phase, at the restriction point. Loss of restriction point control is associated with malignant cellular transformation and cancer. For this reason, identifying genes that are differentially expressed in late G1 phase versus quiescence is important for understanding the molecular basis of normal and malignant growth. MATERIALS AND METHODS: The differential display (DD) method detects mRNA species that are different between sets of mammalian cells, allowing their recovery and cloning of the corresponding cDNAs. Using this technique, we compared mRNAs from synchronized human breast cancer cells (21 PT) in quiescence and in late G1. RESULTS: Six mRNAs differentially expressed in late G1 or in quiescence were identified. One mRNA expressed 10 hr after serum induction showed 99% homology to a peptide transporter involved in antigen presentation of the class I major histocompatibility complex (TAP-1) mRNA. Another mRNA expressed specifically in quiescence and down-regulated 2 hr following serum induction showed 98% homology to human NADP+ -dependent cytoplasmic malic enzyme (EC1.1.1.40) mRNA, which is an important enzyme in fatty acid synthesis and lipogenesis. Three others showed high homology to different mRNAs in the GeneBank, corresponding to genes having unknown functions. Finally, one mRNA revealed no significant homology to known genes in the GeneBank. CONCLUSIONS: We conclude that DD is an efficient and powerful method for the identification of growth-related genes which may have a role in cancer development. Images FIG. 2 FIG. 3 PMID:8827717

  1. Developmental and Cell Cycle Quiescence Is Mediated by the Nuclear Hormone Receptor Coregulator DIN-1S in the Caenorhabditis elegans Dauer Larva.

    PubMed

    Colella, Eileen; Li, Shaolin; Roy, Richard

    2016-08-01

    When faced with suboptimal growth conditions, Caenorhabditis elegans larvae can enter a diapause-like stage called "dauer" that is specialized for dispersal and survival. The decision to form a dauer larva is controlled by three parallel signaling pathways, whereby a compromise of TGFβ, cyclic guanosine monophosphate, or insulin/IGF-like signaling (ILS) results in dauer formation. Signals from these pathways converge on DAF-12, a nuclear hormone receptor that triggers the changes required to initiate dauer formation. DAF-12 is related to the vitamin D, liver-X, and androstane receptors, and like these human receptors, it responds to lipophilic hormone ligands. When bound to its ligand, DAF-12 acquires transcriptional activity that directs reproductive development, while unliganded DAF-12 forms a dauer-specifying complex with its interacting protein DIN-1S to regulate the transcription of genes required for dauer development. We report here that din-1S is required in parallel to par-4/LKB1 signaling within the gonad to establish cell cycle quiescence during the onset of the dauer stage. We show that din-1S is important for postdauer reproduction when ILS is impaired and is necessary for long-term dauer survival in response to reduced ILS. Our work uncovers several previously uncharacterized functions of DIN-1S in executing and maintaining many of the cellular and physiological processes required for appropriate dauer arrest, while also shedding light on the coordination of nuclear hormone signaling, the LKB1/AMPK signaling cascade, and ILS/TGFβ in the control of cell cycle quiescence and tissue growth: a key feature that is often misregulated in a number of hormone-dependent cancers. PMID:27260305

  2. Hubble space telescope Goddard High-Resolution Spectrograph observation of U Geminorum during quiescence: Evidence for a slowly rotating white dwarf

    NASA Technical Reports Server (NTRS)

    Sion, Edward M.; Long, Knox S.; Szkody, Paula; Huang, Min

    1994-01-01

    We have obtained a pair of consecutive far-ultraviolet Goddard High-Resolution Spectrograph (GHRS) exposures of the Si IV region of the dwarf nova U Geminorum in early quiescence, 8 days after its return to optical quiescence when the underlying white dwarf dominates the ultraviolet light of the system. Our GHRS observation revealed a fully resolved line profile for the resonance doublet of Si IV. If it is associated with the white dwarf photosphere, then our best synthetic fits are consistent with T (sub eff) = 35,000 K-38,000 K, log g = 8, a rotational velocity of 50 to 100 km per sec, with a modestly enhanced silicon abundance (1.3-2.3 times solar) and our results suggest that at least in U Gem and perhaps in other similar dwarf novae, the missing boundary layer cannot be explained by rapid rotation of the white dwarf. However, the gamma-velocity of the system remains uncertain. If the gamma-velocity is 43 km per sec (Friend et al. 1990), then a gravitational redshift of approximately 50-60 km per sec is implied for the white dwarf. If the gamma-velocity is 84 km per sec (Wade 1981), then a gravitational redshift of only 10-30 km per sec is indicated, which may imply that either the white dwarf has a low (0.5-0.6 of Solar Mass) mass or an extended atmosphere (corona) due to the outburst heating 8 days earlier. The implications of our line-fitting results for the structure and temperature of boundary layers in cataclysmic variables are discussed.

  3. Hubble Space Telescope high resolution spectroscoy of the exposed white dwarf in the dwarf nova VW Hydri in quiescence: A rapidly rotating white dwarf

    NASA Technical Reports Server (NTRS)

    Sion, Edward M.; Huang, Min; Szkody, Paula; Cheng, Fu-Hua

    1995-01-01

    We obtained a far-ultraviolet spectrum of the dwarf nova VW Hyi in quiescence, with the Hubble Space Telescope Goddard High Resolution Spectrograph covering the region of the Si iv lambda(lambda)1393, 1402 resonance doublet. The broad, shallow Si iv doublet feature is fully resolved, has a total equivalent width of 2.8 A, and is the first metal absorption feature to be clearly detected in the exposed white dwarf. Our synthetic spectral analysis, using a model grid constructed with the code TLUSTY, resulted in a reasonable fit to a white dwarf photosphere with T(sub eff) = 22,000 +/- 2000 K, log g = 8.0 +/- 0.3, an approximately solar Si/H abundance, and a rotational velocity, v sin i approximately equal to 600 km/s. This rotation rate, while not definitive because it is based upon just one line transition, is 20% of the Keplerian (breakup) velocity of the white dwarf and hence does not account for the unexpectedly low boundary-layer luminosity inferred from the soft-X-ray/extreme ultra-violet bands where most of the boundary-layer luminosity should be radiated. The predicted boundary-layer luminosity for a 0.6 solar mass white dwarf accreting at the rate 10(exp -10) solar mass/yr and rotating at 600 km/s, corresponding to VW Hyi in quiescence, is 2 x 10(exp 32) ergs/s when proper account is taken of the rotational kinetic energy going into spinning up the white dwarf. If the boundary-layer area is equal to that of the white dwarf, then T(sub bl) = 24,000 K. This is essentially identical to the photspheric luminosity and temperature determined in far-ultraviolet photospheric analyses. If the boundary-layer area is 10(exp -3) of the white dwarf surface area, then T(sub bl) = 136,000 K.

  4. The cyclin-dependent kinase inhibitor p27 kip1 regulates radial stem cell quiescence and neurogenesis in the adult hippocampus.

    PubMed

    Andreu, Zoraida; Khan, Muhammad Amir; González-Gómez, Pilar; Negueruela, Santiago; Hortigüela, Rafael; San Emeterio, Juana; Ferrón, Sacri R; Martínez, Gloria; Vidal, Anxo; Fariñas, Isabel; Lie, Dieter Chichung; Mira, Helena

    2015-01-01

    Members of the cyclin-dependent kinase (CDK)-inhibitory protein (CIP)/kinase-inhibitory protein (KIP) family of cyclin-dependent kinase inhibitors regulate proliferation and cell cycle exit of mammalian cells. In the adult brain, the CIP/KIP protein p27(kip1) has been related to the regulation of intermediate progenitor cells located in neurogenic niches. Here, we uncover a novel function of p27(kip1) in the adult hippocampus as a dual regulator of stem cell quiescence and of cell-cycle exit of immature neurons. In vivo, p27(kip1) is detected in radial stem cells expressing SOX2 and in newborn neurons of the dentate gyrus. In vitro, the Cdkn1b gene encoding p27(kip1) is transcriptionally upregulated by quiescence signals such as BMP4. The nuclear accumulation of p27(kip1) protein in adult hippocampal stem cells encompasses the BMP4-induced quiescent state and its overexpression is able to block proliferation. p27(kip1) is also expressed in immature neurons upon differentiation of adult hippocampal stem cell cultures. Loss of p27(kip1) leads to an increase in proliferation and neurogenesis in the adult dentate gyrus, which results from both a decrease in the percentage of radial stem cells that are quiescent and a delay in cell cycle exit of immature neurons. Analysis of animals carrying a disruption in the cyclin-CDK interaction domain of p27(kip1) indicates that the CDK inhibitory function of the protein is necessary to control the activity of radial stem cells. Thus, we report that p27(kip1) acts as a central player of the molecular program that keeps adult hippocampal stem cells out of the cell cycle.

  5. Restless Legs Syndrome

    MedlinePlus

    ... brain’s basal ganglia circuits that use the neurotransmitter dopamine, which is needed to produce smooth, purposeful muscle ... Parkinson’s disease, another disorder of the basal ganglia’s dopamine pathways, often have RLS as well. RLS also ...

  6. Restless Legs Syndrome Foundation

    MedlinePlus

    ... Syndrome Foundation is a registered 501(c)3 non-profit corporation (Tax ID #56-1784846). Donations are tax- ... Syndrome Foundation is a registered 501(c)3 non-profit corporation (Tax ID #56-1784846). Donations are tax- ...

  7. The Restless Mind

    ERIC Educational Resources Information Center

    Smallwood, Jonathan; Schooler, Jonathan W.

    2006-01-01

    This article reviews the hypothesis that mind wandering can be integrated into executive models of attention. Evidence suggests that mind wandering shares many similarities with traditional notions of executive control. When mind wandering occurs, the executive components of attention appear to shift away from the primary task, leading to failures…

  8. David Gale: Restless Pioneer

    ERIC Educational Resources Information Center

    Meyer, Walter

    2006-01-01

    David Gale was one of the mathematicians responsible for the modern form of the theory of duality in linear programming and the associated proof of the minimax theorem in the theory of games. He is a member of the National Academy of Sciences and is Professor Emeritus of Mathematics and Operations Research at the University of California at…

  9. REST and the RESTless

    PubMed Central

    Gopalakrishnan, Vidya

    2009-01-01

    Since its original discovery as a negative regulator of neuronal differentiation, the repressor element (RE)-1 silencing transcription factor (REST), also known as the neuron-restrictive silencer factor, has been implicated in novel processes such as maintenance of embryonic stem cell pluripotency and self-renewal and regulation of mitotic fidelity in non-neural cells. REST expression and activity is tightly controlled by transcriptional and post-transcriptional mechanisms in a cell and developmental stage-specific manner and perturbations in its levels or function are associated with various pathological states. REST differentially influences target-gene expression through interaction with a wide variety of cellular cofactors in a context-dependent manner. However, the influence of the microenvironment on REST-mediated regulation of gene expression is poorly understood. This review will present our current understanding of REST signaling with a greater focus on its emerging ties with noncoding RNAs and novel interacting partners, as well as its roles in embryonic stem cell self-renewal, cellular plasticity and oncogenesis/tumor suppression. PMID:19885378

  10. Neutrino Signal of Collapse-induced Thermonuclear Supernovae: The Case for Prompt Black Hole Formation in SN 1987A

    NASA Astrophysics Data System (ADS)

    Blum, Kfir; Kushnir, Doron

    2016-09-01

    Collapse-induced thermonuclear explosion (CITE) may explain core-collapse supernovae (CCSNe). We analyze the neutrino signal in CITE and compare it to the neutrino burst of SN 1987A. For strong (≳ {10}51 erg) CCSNe, such as SN 1987A, CITE predicts a proto-neutron star (PNS) accretion phase lasting up to a few seconds that is cut off by black hole (BH) formation. The neutrino luminosity can later be revived by accretion disk emission after a dead time of a few to a few tens of seconds. In contrast, the neutrino mechanism for CCSNe predicts a short (≲s) PNS accretion phase, followed by slowly declining PNS cooling luminosity. We repeat statistical analyses used in the literature to interpret the neutrino mechanism, and apply them to CITE. The first 1–2 s of the neutrino burst are equally compatible with CITE and with the neutrino mechanism. However, the data points toward a luminosity drop at t = 2–3 s, which is in some tension with the neutrino mechanism but can be naturally attributed to BH formation in CITE. The occurrence of neutrino signal events at 5 s suggests that, within CITE, the accretion disk formed by that time. We perform two-dimensional numerical simulations showing that CITE may be able to accommodate this disk formation time while reproducing the ejected 56Ni mass and ejecta kinetic energy within factors of 2–3 of observations. We estimate the accretion disk neutrino luminosity, finding it to be on the low side but compatible with the data to a factor of 10. Given comparable uncertainties in the disk luminosity simulation, we conclude that direct BH formation may have occurred in SN 1987A.

  11. Neutrino Signal of Collapse-induced Thermonuclear Supernovae: The Case for Prompt Black Hole Formation in SN 1987A

    NASA Astrophysics Data System (ADS)

    Blum, Kfir; Kushnir, Doron

    2016-09-01

    Collapse-induced thermonuclear explosion (CITE) may explain core-collapse supernovae (CCSNe). We analyze the neutrino signal in CITE and compare it to the neutrino burst of SN 1987A. For strong (≳ {10}51 erg) CCSNe, such as SN 1987A, CITE predicts a proto-neutron star (PNS) accretion phase lasting up to a few seconds that is cut off by black hole (BH) formation. The neutrino luminosity can later be revived by accretion disk emission after a dead time of a few to a few tens of seconds. In contrast, the neutrino mechanism for CCSNe predicts a short (≲s) PNS accretion phase, followed by slowly declining PNS cooling luminosity. We repeat statistical analyses used in the literature to interpret the neutrino mechanism, and apply them to CITE. The first 1-2 s of the neutrino burst are equally compatible with CITE and with the neutrino mechanism. However, the data points toward a luminosity drop at t = 2-3 s, which is in some tension with the neutrino mechanism but can be naturally attributed to BH formation in CITE. The occurrence of neutrino signal events at 5 s suggests that, within CITE, the accretion disk formed by that time. We perform two-dimensional numerical simulations showing that CITE may be able to accommodate this disk formation time while reproducing the ejected 56Ni mass and ejecta kinetic energy within factors of 2-3 of observations. We estimate the accretion disk neutrino luminosity, finding it to be on the low side but compatible with the data to a factor of 10. Given comparable uncertainties in the disk luminosity simulation, we conclude that direct BH formation may have occurred in SN 1987A.

  12. XPS, SIMS and FTIR-ATR characterization of boronized graphite from the thermonuclear plasma device RFX-mod

    NASA Astrophysics Data System (ADS)

    Ghezzi, F.; Laguardia, L.; Caniello, R.; Canton, A.; Dal Bello, S.; Rais, B.; Anderle, M.

    2015-11-01

    In this paper the characterization of a thin (tens of nanometers) boron layer on fine grain polycrystalline graphite substrate is presented. The boron film is used as conditioning technique for the full graphite wall of the Reversed Field eXperiment-modified (RFX-mod) experiment, a device for the magnetic confinement of plasmas of thermonuclear interest. Aim of the present analysis is to enlighten the chemical structure of the film, the trapping mechanism that makes it a getter for oxygen and hydrogen and the reason of its loss of effectiveness after exposure to about 100 s of hydrogen plasma. X-ray Photoelectron Spectroscopy (XPS), Secondary Ions Mass Spectrometry (SIMS) and Fourier Transform Infra Red spectroscopy in combination with the Attenuated Total Reflectance (FTIR-ATR) were used to obtain the structure and the chemical composition of graphitic samples as coated or coated and subsequently exposed to hydrogen plasma after boron deposition. The boron layers on the only coated samples were found to be amorphous hydrogenated boron carbide plus a variety of bonds like B-B, B-H, B-O, B-OH, C-C, C-H, C-O, C-OH. Both the thickness and the homogeneity of the layers were found to depend on the distance of the sample from the anode during the deposition. The samples contained oxygen along the layer thickness, at level of 5%, bound to boron. The gettering action of the boron is therefore already active during the deposition itself. The exposure to plasma caused erosion of the boron film and higher content of H and O bound to boron throughout the whole thickness. The interaction of the B layer with plasma is therefore a bulk phenomenon.

  13. Efficacy of orally administered Silexan in patients with anxiety-related restlessness and disturbed sleep--A randomized, placebo-controlled trial.

    PubMed

    Kasper, Siegfried; Anghelescu, Ion; Dienel, Angelika

    2015-11-01

    The anxiolytic effect of Silexan, a patented active substance with an essential oil produced from Lavandula angustifolia flowers, was investigated in patients with anxiety-related restlessness and disturbed sleep. 170 out-patients with a diagnosis of restlessness (ICD-10 R45.1), a Hamilton Anxiety Scale (HAMA) total score ≥18 points and ≥2 points for HAMA items 'Tension' and 'Insomnia' participated in this randomized, double-blind trial and received 80mg Silexan or placebo once daily for 10 weeks. Patients with clinically important other psychiatric or neurological disorders potentially interfering with the assessment of treatment efficacy were excluded. Outcome variables were the HAMA as well as the Pittsburgh Sleep Quality Index (PSQI), the Zung Self-rating Anxiety Scale, a State Check inventory and the Clinical Global Impressions questionnaire. In the Silexan group the HAMA total score decreased from an average of 25.5±6.0 points at baseline to 13.7±7.0 points at treatment end, compared to a decrease from 26.5±6.1 to 16.9±9.8 for placebo, corresponding to decreases of 12.0 and 9.3 points (marginal means), respectively (group difference: p=0.03, ANCOVA with factor treatment and baseline value as covariate). In all outcome measures the treatment effect of Silexan was more pronounced than with placebo. According to the HAMA, 48.8% and 33.3% of the patients were responders (Silexan, placebo; reduction ≥50%; p=0.04) and 31.4% and 22.6% achieved remission (HAMA<10; p=0.20). 33.7% (Silexan) and 35.7% (placebo) of the participants reported adverse events. The study confirms the calming and anxiolytic efficacy of Silexan. PMID:26293583

  14. In restless legs syndrome, the neural substrates of the sensorimotor symptoms are also normally involved in upright standing posture and biped walking.

    PubMed

    Akpinar, Sevket

    2009-08-01

    Restless legs syndrome (RLS) exhibits sensorimotor symptoms. In familial cases, a gene at chromosomal location 9p-24-22 is linked to RLS and the expressed mutation is Dopamine Receptor Specific Individual Sensitivity (DRSIS). The symptoms are triggered during changes in alertness, generally at sleep hours, resulting from insufficient dopamine transmission. The conscious experience of sensory abnormalities are described as 'an urge to move the limbs with or without paresthesias' leading to motor signs such as periodic limb movements and motor restlessness which exhibit temporary loss of extensor motor system dominance over the flexor motor system of the upright posture. The relationship of the expressed mutation to EEG alpha activity makes RLS a sleep disorder as well as a cognitive dysfunction. The recurrent character of sensorimotor symptoms impede the patient's ability to sleep, wake and force to move leading to insomnia. In Uner Tan Syndrome, the nonsense mutation in the same gene leads to underdevelopment of the neural substrates of upright posture. The defects include dopamine receptor deficiency (DRD) leading to severe cognitive dysfunctions and motor disorders-complete loss of extensor motor system dominance over the flexor motor system-quadrupedality, primitive speech, cerebellar symptoms, and strabismus. Comparisons between the neural substrates of sensorimotor symptoms seen in RLS and MRI findings for cases of Uner Tan Syndrome show cortico-cerebellar hypoplasias in the neural networks involved in upright posture. Both RLS and Uner Tan Syndrome seem to be due to different mutations in the dopamine receptor gene at 9p-24 locus, affecting the diencephalon dopaminergic system and the neural networks involved in upright posture. PMID:19394150

  15. In restless legs syndrome, the neural substrates of the sensorimotor symptoms are also normally involved in upright standing posture and biped walking.

    PubMed

    Akpinar, Sevket

    2009-08-01

    Restless legs syndrome (RLS) exhibits sensorimotor symptoms. In familial cases, a gene at chromosomal location 9p-24-22 is linked to RLS and the expressed mutation is Dopamine Receptor Specific Individual Sensitivity (DRSIS). The symptoms are triggered during changes in alertness, generally at sleep hours, resulting from insufficient dopamine transmission. The conscious experience of sensory abnormalities are described as 'an urge to move the limbs with or without paresthesias' leading to motor signs such as periodic limb movements and motor restlessness which exhibit temporary loss of extensor motor system dominance over the flexor motor system of the upright posture. The relationship of the expressed mutation to EEG alpha activity makes RLS a sleep disorder as well as a cognitive dysfunction. The recurrent character of sensorimotor symptoms impede the patient's ability to sleep, wake and force to move leading to insomnia. In Uner Tan Syndrome, the nonsense mutation in the same gene leads to underdevelopment of the neural substrates of upright posture. The defects include dopamine receptor deficiency (DRD) leading to severe cognitive dysfunctions and motor disorders-complete loss of extensor motor system dominance over the flexor motor system-quadrupedality, primitive speech, cerebellar symptoms, and strabismus. Comparisons between the neural substrates of sensorimotor symptoms seen in RLS and MRI findings for cases of Uner Tan Syndrome show cortico-cerebellar hypoplasias in the neural networks involved in upright posture. Both RLS and Uner Tan Syndrome seem to be due to different mutations in the dopamine receptor gene at 9p-24 locus, affecting the diencephalon dopaminergic system and the neural networks involved in upright posture.

  16. Method and system to directly produce electrical power within the lithium blanket region of a magnetically confined, deuterium-tritium (DT) fueled, thermonuclear fusion reactor

    DOEpatents

    Woolley, Robert D.

    1999-01-01

    A method for integrating liquid metal magnetohydrodynamic power generation with fusion blanket technology to produce electrical power from a thermonuclear fusion reactor located within a confining magnetic field and within a toroidal structure. A hot liquid metal flows from a liquid metal blanket region into a pump duct of an electromagnetic pump which moves the liquid metal to a mixer where a gas of predetermined pressure is mixed with the pressurized liquid metal to form a Froth mixture. Electrical power is generated by flowing the Froth mixture between electrodes in a generator duct. When the Froth mixture exits the generator the gas is separated from the liquid metal and both are recycled.

  17. The problems associated with the monitoring of complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities.

    PubMed

    Bilski, P; Blomgren, J; d'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2007-01-01

    The European Commission is funding within its Sixth Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organisational framework for this project is provided by the European Radiation Dosimetry Group EURADOS. One task within the CONRAD project, Work Package 6 (WP6), was to provide a report outlining research needs and research activities within Europe to develop new and improved methods and techniques for the characterisation of complex radiation fields at workplaces around high-energy accelerators, but also at the next generation of thermonuclear fusion facilities. The paper provides an overview of the report, which will be available as CERN Yellow Report.

  18. Method and System to Directly Produce Electrical Power within the Lithium Blanket Region of a Magnetically Confined, Deuterium-Tritium (DT) Fueled, Thermonuclear Fusion Reactor

    SciTech Connect

    Woolley, Robert D.

    1998-09-22

    A method for integrating liquid metal magnetohydrodynamic power generation with fusion blanket technology to produce electrical power from a thermonuclear fusion reactor located within a confining magnetic field and within a toroidal structure. A hot liquid metal flows from a liquid metal blanket region into a pump duct of an electromagnetic pump which moves the liquid metal to a mixer where a gas of predetermined pressure is mixed with the pressurized liquid metal to form a Froth mixture. Electrical power is generated by flowing the Froth mixture between electrodes in a generator duct. When the Froth mixture exits the generator the gas is separated from the liquid metal and both are recycled.

  19. Preparation and characterization of carbons for the retention of halogens in the condenser vacuum system of a thermonuclear plant

    NASA Astrophysics Data System (ADS)

    Román, S.; González, J. F.; Gañán, J.; Sabio, E.; González-García, C. M.; Ramiro, A.; Mangut, V.

    2006-06-01

    Activated carbons were prepared by air and carbon dioxide activation, from almond tree pruning, with the aim of obtaining carbons that reproduce the textural and mechanical properties of the carbons currently used in the filtering system of the condenser vacuum installation of a Thermonuclear Plant (CNA; Central Nuclear de Almaraz in Caceres, Spain), produced from coconut shell. The variables studied in non-catalytic gasification series with air were the temperature (215-270 °C) and the time (1-16 h) and the influence of the addition of one catalyst (Co) and the time (1-2 h) in catalytic gasification. In the case of activation with CO 2, the influence of the temperature (700-950 °C) and the time (1-8 h) was studied. The resulting carbons were characterized in terms of their BET surface, porosity, and pore size distribution. The N 2 adsorption isotherms at 77 K for both series showed a type I behaviour, typical of microporous materials. The isotherms showed that with both gasificant agents the temperature rise produced an increase in the carbon porosity. With regards to the activation time, a positive effect on the N 2 adsorbed volume on the carbons was observed. The best carbons of each series, as well as the CNA (carbon currently used in the CNA), were characterized by mercury porosimetry and iodine solution adsorption isotherms. The results obtained allowed to state that several of the carbons produced had characteristics similar to the carbon that is target of reproduction (which has SBET of 741 m 2 g -1, Vmi of 0.39 cm 3 g -1 and a iodine retention capacity of 429.3 mg g -1): carbon C (gasification with CO 2 at 850 °C during 1 h), with SBET of 523 m 2 g -1, Vmi of 0.33 cm 3 g -1 and a iodine retention capacity of 402.5 mg g -1, and carbon D (gasification with CO 2 at 900 °C during 1 h), whose SBET is 672 m 2 g -1, Vmi is 0.28 cm 3 g -1 and has a iodine retention capacity of 345.2 mg g -1.

  20. Thermonuclear Data File.

    1992-05-05

    Version 00 The library contains reaction rates and spectral information (for 2-body reactions only) about the outgoing particles in plasma as a function of temperature. The range of plasma temperatures is from 0.1 to 1000 keV. The library was intended for use in fusion applications.

  1. Daily multiwavelength Swift monitoring of the neutron star low-mass X-ray binary Cen X-4: evidence for accretion and reprocessing during quiescence

    NASA Astrophysics Data System (ADS)

    Bernardini, F.; Cackett, E. M.; Brown, E. F.; D'Angelo, C.; Degenaar, N.; Miller, J. M.; Reynolds, M.; Wijnands, R.

    2013-12-01

    We conducted the first long-term (60 d), multiwavelength (optical, ultraviolet, UV, and X-ray) simultaneous monitoring of Cen X-4 with daily Swift observations from 2012 June to August, with the goal of understanding variability in the low-mass X-ray binary Cen X-4 during quiescence. We found Cen X-4 to be highly variable in all energy bands on time-scales from days to months, with the strongest quiescent variability a factor of 22 drop in the X-ray count rate in only 4 d. The X-ray, UV and optical (V band) emission are correlated on time-scales down to less than 110 s. The shape of the correlation is a power law with index γ about 0.2-0.6. The X-ray spectrum is well fitted by a hydrogen neutron star (NS) atmosphere (kT = 59-80 eV) and a power law (with spectral index Γ = 1.4-2.0), with the spectral shape remaining constant as the flux varies. Both components vary in tandem, with each responsible for about 50 per cent of the total X-ray flux, implying that they are physically linked. We conclude that the X-rays are likely generated by matter accreting down to the NS surface. Moreover, based on the short time-scale of the correlation, we also unambiguously demonstrate that the UV emission cannot be due to either thermal emission from the stream impact point, or a standard optically thick, geometrically thin disc. The spectral energy distribution shows a small UV emitting region, too hot to arise from the accretion disc, that we identified as a hotspot on the companion star. Therefore, the UV emission is most likely produced by reprocessing from the companion star, indeed the vertical size of the disc is small and can only reprocess a marginal fraction of the X-ray emission. We also found the accretion disc in quiescence to likely be UV faint, with a minimal contribution to the whole UV flux.

  2. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+{sup 11}B process

    SciTech Connect

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-15

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+{sup 11}B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from {sup 11}B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+{sup 11}B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+{sup 11}B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+{sup 11}B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  3. The LOFT perspective on neutron star thermonuclear bursts: White paper in support of the mission concept of the large observatory for X-ray timing

    SciTech Connect

    in't Zand, J. J.M.; Malone, Christopher M.; Altamirano, D.; Ballantyne, D. R.; Bhattacharyya, S.; Brown, E. F.; Cavecchi, Y.; Chakrabarty, D.; Chenevez, J.; Cumming, A.; Degenaar, N.; Falanga, M.; Galloway, D. K.; Heger, A.; Jose, J.; Keek, L.; Linares, M.; Mahmoodifar, S.; Mendez, M.; Miller, M. C.; Paerels, F. B. S.; Poutanen, J.; Rozanska, A.; Schatz, H.; Serino, M.; Strohmayer, T. E.; Suleimanov, V. F.; Thielemann, F. -K.; Watts, A. L.; Weinberg, N. N.; Woosley, S. E.; Yu, W.; Zhang, S.; Zingale, M.

    2015-01-14

    The Large Area Detector (LAD) on the Large Observatory For X-ray Timing ( LOFT ), with a 8.5 m 2 photon- collecting area in the 2–30 keV bandpass at CCD-class spectral resolving power (λ/Δλ = 10 – 100), is designed for optimum performance on bright X-ray sources. Thus, it is well-suited to study thermonuclear X-ray bursts from Galactic neutron stars. These bursts will typically yield 2 x 105 photon detections per second in the LAD, which is at least 15 times more than with any other instrument past, current or anticipated. The Wide Field Monitor (WFM) foreseen for LOFT uniquely combines 2–50 keV imaging with large (30%) prompt sky coverage. This will enable the detection of tens of thousands of thermonuclear X-ray bursts during a 3-yr mission, including tens of superbursts. Both numbers are similar or more than the current database gathered in 50 years of X-ray astronomy.

  4. An Improved Reaction Rate Formulation for Charged-Particle Induced Thermonuclear Reaction of {sup 2}H(d,{gamma}){sup 4}He

    SciTech Connect

    Aziz, Azni Abdul; Yusof, Norhasliza; Idris, Mahirah; Kassim, Hasan Abu

    2011-03-30

    The reaction rate formula utilized in compilations such as the Nuclear Astrophysics Compilation of Reaction Rates (NACRE) uses low energy approximation due to temperatures in stars are in the region of a few keVs. Most nuclear reaction experiments were done in MeV range and the interior temperatures of massive stars are {approx}10{sup 9} K. Hence an improved formulation for calculating the nuclear reaction rate that is applicable to high temperatures is discussed in this work. The exact tunneling probability that is applicable for all energies is obtained by solving the Schroedinger equation. This yields an enhanced expression for the astrophysical S-factor for calculating the thermonuclear reaction rate at high temperature. The thermonuclear reaction rate from this work is applied to the {sup 2}H(d,{gamma}){sup 4}He reaction and is compared with the NACRE compilation. This improved reaction rate can be included in the nuclear reaction network in a Big Bang nucleosynthesis (BBN) code or a stellar nuclear network code.

  5. On the Optical-X-Ray Correlation from Outburst to Quiescence in Low-mass X-Ray Binaries: The Representative Cases of V404 Cyg and Cen X-4

    NASA Astrophysics Data System (ADS)

    Bernardini, F.; Russell, D. M.; Kolojonen, K. I. I.; Stella, L.; Hynes, R. I.; Corbel, S.

    2016-08-01

    Low-mass X-ray binaries (LMXBs) show evidence of a global correlation of debated origin between X-ray and optical luminosity. We study for the first time this correlation in two transient LMXBs, the black hole (BH) V404 Cyg and the neutron star Cen X-4, over six orders of magnitude in X-ray luminosity, from outburst to quiescence. After subtracting the contribution from the companion star, the Cen X-4 data can be described by a single power-law correlation of the form {L}{opt}\\propto {L}{{X}}0.44, consistent with disk reprocessing. We find a similar correlation slope for V404 Cyg in quiescence (0.46) and a steeper one (0.56) in the outburst hard state of 1989. However, V404 Cyg is about 160-280 times optically brighter, at a given 3-9 keV X-ray luminosity, compared to Cen X-4. This ratio is a factor of 10 smaller in quiescence, where the normalization of the V404 Cyg correlation also changes. Once the bolometric X-ray emission is considered and the known main differences between V404 Cyg and Cen X-4 are taken into account (a larger compact object mass, accretion disk size, and the presence of a strong jet contribution in the hard state for the BH system), the two systems lie on the same correlation. In V404 Cyg, the jet dominates spectrally at optical-infrared frequencies during the hard state but makes a negligible contribution in quiescence, which may account for the change in its correlation slope and normalization. These results provide a benchmark to compare with data from the 2015 outburst of V404 Cyg and, potentially, other transient LMXBs as well.

  6. Risk of Cardiovascular Disease Associated with a Restless Legs Syndrome Diagnosis in a Retrospective Cohort Study from Kaiser Permanente Northern California

    PubMed Central

    Van Den Eeden, Stephen K.; Albers, Kathleen B.; Davidson, Julie E.; Kushida, Clete A.; Leimpeter, Amethyst D.; Nelson, Lorene M.; Popat, Rita; Tanner, Caroline M.; Bibeau, Kristen; Quesenberry, Charles P.

    2015-01-01

    Introduction: Recent cross-sectional studies suggest that restless legs syndrome (RLS) may be associated with an increased prevalence of cardiovascular disease (CVD) comorbidity or risk factors. We evaluated whether primary or secondary RLS was associated with an increased risk of incident cardiovascular disease in a retrospective cohort study within Kaiser Permanente Northern California (KPNC). Methods: We identified members of KPNC with primary RLS and secondary RLS between 1999 and 2008 by an algorithm that incorporated longitudinal clinical records related to the diagnosis and treatment of RLS and comorbidities. We then matched each RLS case with up to 50 individuals with no clinical records of RLS by age, sex, race/ethnicity, zip code, and membership duration. For the analyses we excluded any individual with coronary artery disease (CAD: angina, acute myocardial infarction, coronary revascularization procedure, CAD death), CVD (CAD plus stroke), and hypertension at baseline. New cardiovascular events were determined from clinical records. Follow-up ended at an outcome event, disenrollment from KPNC, or death, whichever occurred earliest. There were over 473,358 person-y of follow-up in this cohort analysis with a mean follow-up time of 3.91 y and range from 6 mo to 12 y. Survival analysis techniques, including survival curves and proportional hazard regression models, were used to assess the association between RLS status and CVD. Results: There were 7,621 primary RLS and 4,507 secondary RLS cases identified and included in the study. In general, primary RLS cases were younger and had less comorbidity than secondary RLS cases. During the follow-up period, CVD was diagnosed in 478 primary RLS cohort members, CAD was diagnosed in 310, and hypertension events were identified in 1,466. Diagnosis in secondary RLS cohort members was made during the follow-up period with 451, 338, and 598 CVD, CAD, and hypertension events, respectively. Subjects with primary RLS had

  7. A loss-of-function mutation in the PAS kinase Rim15p is related to defective quiescence entry and high fermentation rates of Saccharomyces cerevisiae sake yeast strains.

    PubMed

    Watanabe, Daisuke; Araki, Yuya; Zhou, Yan; Maeya, Naoki; Akao, Takeshi; Shimoi, Hitoshi

    2012-06-01

    Sake yeast cells have defective entry into the quiescent state, allowing them to sustain high fermentation rates. To reveal the underlying mechanism, we investigated the PAS kinase Rim15p, which orchestrates initiation of the quiescence program in Saccharomyces cerevisiae. We found that Rim15p is truncated at the carboxyl terminus in modern sake yeast strains as a result of a frameshift mutation. Introduction of this mutation or deletion of the full-length RIM15 gene in a laboratory strain led to a defective stress response, decreased synthesis of the storage carbohydrates trehalose and glycogen, and impaired G(1) arrest, which together closely resemble the characteristic phenotypes of sake yeast. Notably, expression of a functional RIM15 gene in a modern sake strain suppressed all of these phenotypes, demonstrating that dysfunction of Rim15p prevents sake yeast cells from entering quiescence. Moreover, loss of Rim15p or its downstream targets Igo1p and Igo2p remarkably improved the fermentation rate in a laboratory strain. This finding verified that Rim15p-mediated entry into quiescence plays pivotal roles in the inhibition of ethanol fermentation. Taken together, our results suggest that the loss-of-function mutation in the RIM15 gene may be the key genetic determinant of the increased ethanol production rates in modern sake yeast strains.

  8. Resistance to dehydration between bouts of blood feeding in the bed bug, Cimex lectularius, is enhanced by water conservation, aggregation, and quiescence.

    PubMed

    Benoit, Joshua B; Del Grosso, Nicholas A; Yoder, Jay A; Denlinger, David L

    2007-05-01

    To determine how the bed bug, Cimex lectularius, survives in a dry environment for many months without feeding, water-balance characteristics were compared for all stages from first-instar nymphs to adults. This species is characterized by a low net transpiration rate averaging < 0.2%/h, high tolerance for dehydration (30-40% loss in body water), and an impermeable cuticle as indicated by a high critical transition temperature (CTT) in the 35-40 degrees C range, implying that this insect is adapted for desiccation-hardiness. The capacity of adults to survive for 2 weeks at 0.00a(v) (a(v) = % RH/100) with no access to food or water exemplifies this trait. In contrast to more mature stages, first-instar nymphs contain more water, lose water at a faster rate, experience abrupt water loss at a lower temperature, and survive less time in dry air, suggesting that this stage is the most sensitive to water stress. This insect relies on blood to replenish water stores; none of the stages examined have the capacity to absorb water vapor (critical equilibrium activity, CEA > or = 0.99a(v)), and they drank only sparingly when offered free water. As the bed bugs progress through their development, they gradually reduce their water requirements while increasing their desiccation resistance. Surviving water stress is considerably enhanced behaviorally by quiescence, characterized by prolonged periods of inactivity, and by the formation of clusters that generate a water-conserving group effect.

  9. Melanoma dormancy in a mouse model is linked to GILZ/FOXO3A-dependent quiescence of disseminated stem-like cells.

    PubMed

    Touil, Yasmine; Segard, Pascaline; Ostyn, Pauline; Begard, Severine; Aspord, Caroline; El Machhour, Raja; Masselot, Bernadette; Vandomme, Jerome; Flamenco, Pilar; Idziorek, Thierry; Figeac, Martin; Formstecher, Pierre; Quesnel, Bruno; Polakowska, Renata

    2016-01-01

    Metastatic cancer relapses following the reactivation of dormant, disseminated tumour cells; however, the cells and factors involved in this reactivation are just beginning to be identified. Using an immunotherapy-based syngeneic model of melanoma dormancy and GFP-labelled dormant cell-derived cell lines, we determined that vaccination against melanoma prevented tumour growth but did not prevent tumour cell dissemination or eliminate all tumour cells. The persistent disseminated melanoma tumour cells were quiescent and asymptomatic for one year. The quiescence/activation of these cells in vitro and the dormancy of melanoma in vivo appeared to be regulated by glucocorticoid-induced leucine zipper (GILZ)-mediated immunosuppression. GILZ expression was low in dormant cell-derived cultures, and re-expression of GILZ inactivated FOXO3A and its downstream target, p21CIP1. The ability of dormancy-competent cells to re-enter the cell cycle increased after a second round of cellular dormancy in vivo in association with shortened tumour dormancy period and faster and more aggressive melanoma relapse. Our data indicate that future cancer treatments should be adjusted according to the stage of disease progression.

  10. Melanoma dormancy in a mouse model is linked to GILZ/FOXO3A-dependent quiescence of disseminated stem-like cells

    PubMed Central

    Touil, Yasmine; Segard, Pascaline; Ostyn, Pauline; Begard, Severine; Aspord, Caroline; El Machhour, Raja; Masselot, Bernadette; Vandomme, Jerome; Flamenco, Pilar; Idziorek, Thierry; Figeac, Martin; Formstecher, Pierre; Quesnel, Bruno; Polakowska, Renata

    2016-01-01

    Metastatic cancer relapses following the reactivation of dormant, disseminated tumour cells; however, the cells and factors involved in this reactivation are just beginning to be identified. Using an immunotherapy-based syngeneic model of melanoma dormancy and GFP-labelled dormant cell-derived cell lines, we determined that vaccination against melanoma prevented tumour growth but did not prevent tumour cell dissemination or eliminate all tumour cells. The persistent disseminated melanoma tumour cells were quiescent and asymptomatic for one year. The quiescence/activation of these cells in vitro and the dormancy of melanoma in vivo appeared to be regulated by glucocorticoid-induced leucine zipper (GILZ)-mediated immunosuppression. GILZ expression was low in dormant cell-derived cultures, and re-expression of GILZ inactivated FOXO3A and its downstream target, p21CIP1. The ability of dormancy-competent cells to re-enter the cell cycle increased after a second round of cellular dormancy in vivo in association with shortened tumour dormancy period and faster and more aggressive melanoma relapse. Our data indicate that future cancer treatments should be adjusted according to the stage of disease progression. PMID:27465291

  11. Melanoma dormancy in a mouse model is linked to GILZ/FOXO3A-dependent quiescence of disseminated stem-like cells.

    PubMed

    Touil, Yasmine; Segard, Pascaline; Ostyn, Pauline; Begard, Severine; Aspord, Caroline; El Machhour, Raja; Masselot, Bernadette; Vandomme, Jerome; Flamenco, Pilar; Idziorek, Thierry; Figeac, Martin; Formstecher, Pierre; Quesnel, Bruno; Polakowska, Renata

    2016-01-01

    Metastatic cancer relapses following the reactivation of dormant, disseminated tumour cells; however, the cells and factors involved in this reactivation are just beginning to be identified. Using an immunotherapy-based syngeneic model of melanoma dormancy and GFP-labelled dormant cell-derived cell lines, we determined that vaccination against melanoma prevented tumour growth but did not prevent tumour cell dissemination or eliminate all tumour cells. The persistent disseminated melanoma tumour cells were quiescent and asymptomatic for one year. The quiescence/activation of these cells in vitro and the dormancy of melanoma in vivo appeared to be regulated by glucocorticoid-induced leucine zipper (GILZ)-mediated immunosuppression. GILZ expression was low in dormant cell-derived cultures, and re-expression of GILZ inactivated FOXO3A and its downstream target, p21CIP1. The ability of dormancy-competent cells to re-enter the cell cycle increased after a second round of cellular dormancy in vivo in association with shortened tumour dormancy period and faster and more aggressive melanoma relapse. Our data indicate that future cancer treatments should be adjusted according to the stage of disease progression. PMID:27465291

  12. Phosphorylation of eIF2α Is a Translational Control Mechanism Regulating Muscle Stem Cell Quiescence and Self-Renewal.

    PubMed

    Zismanov, Victoria; Chichkov, Victor; Colangelo, Veronica; Jamet, Solène; Wang, Shuo; Syme, Alasdair; Koromilas, Antonis E; Crist, Colin

    2016-01-01

    Regeneration of adult tissues depends on somatic stem cells that remain quiescent yet are primed to enter a differentiation program. The molecular pathways that prevent activation of these cells are not well understood. Using mouse skeletal muscle stem cells as a model, we show that a general repression of translation, mediated by the phosphorylation of translation initiation factor eIF2α at serine 51 (P-eIF2α), is required to maintain the quiescent state. Skeletal muscle stem cells unable to phosphorylate eIF2α exit quiescence, activate the myogenic program, and differentiate, but do not self-renew. P-eIF2α ensures in part the robust translational silencing of accumulating mRNAs that is needed to prevent the activation of muscle stem cells. Additionally, P-eIF2α-dependent translation of mRNAs regulated by upstream open reading frames (uORFs) contributes to the molecular signature of stemness. Pharmacological inhibition of eIF2α dephosphorylation enhances skeletal muscle stem cell self-renewal and regenerative capacity.

  13. Successful treatment with clonazepam and pramipexole of a patient with sleep-related eating disorder associated with restless legs syndrome: a case report.

    PubMed

    Kobayashi, Nobuyuki; Yoshimura, Ryohei; Takano, Masahiro

    2012-01-01

    Sleep-related eating disorder (SRED) is characterized by recurrent episodes of involuntary eating during sleep period and is often associated with restless legs syndrome (RLS). Although pharmacotherapy is recommended for SRED patients, no drug have shown promising effects so far. The patient, a 48-year-old Japanese housewife, first visited our clinic and complained about nighttime eating. She had a history of hypertension, diabetes mellitus, sleep apnea syndrome, and depression. Insomnia appeared 10 years before the first visit and she often received hypnosedatives; at the same time, she developed nocturnal eating episodes. She had amnesia for these episodes, and she felt urge to move her legs while sleeping. The patient was diagnosed with SRED and RLS. Reduction in the doses of triazolam decreased her nighttime eating frequency, and her complete amnesia changed to vague recall of eating during night. Clonazepam 1.0 mg at bedtime decreased nocturnal eating frequency from 1 to 2 times per month, though sleepwalking remained. Administration of pramipexole 0.125 mg relieved all symptoms including SRED, RLS, and sleepwalking. This is the first paper to report that the combination of clonazepam and pramipexole therapy-reduced SRED episodes and RLS symptoms.

  14. Sources, Ascent and Release of Magma and Hydrothermal Fluids at Restless Calderas: Lessons from Santorini Volcano, Greece and Aluto Volcano, Ethiopia

    NASA Astrophysics Data System (ADS)

    Hutchison, W.; Mather, T. A.; Parks, M.; Pyle, D. M.; Biggs, J.; Nomikou, P.; Yirgu, G.; Fischer, T. P.; Caliro, S.; Chiodini, G.

    2014-12-01

    Understanding the behavior of magma and hydrothermal fluids at restless calderas is important for many reasons. The interplay between the magmatic and hydrothermal systems at caldera-forming volcanoes is key to interpreting many of the geophysical signals measured at the surface used to understand their subsurface state and structure. Several recent studies have highlighted that structural controls may be important in terms of the movements of both types of fluids in the Earth's crust below volcanoes with implications including hazard management and geothermal prospecting. Caldera-forming systems are often characterized by eruptive activity covering a wide range of size scales and repose intervals. Understanding how these different scales of volcanism at the same system relate to each other is a key science challenge when seeking to understand these types of volcano. This presentation will explore these issues using examples from two caldera-forming systems. Santorini volcano in Greece is a relatively well-studied system that last erupted significantly about 75 years ago and has recently experienced a period of unusual unrest. Aluto volcano in Ethiopia is more poorly studied but has been shown to be actively deforming and is an area of focus for investment in geothermal power in the Main Ethiopian Rift. In each case lessons from field mapping and geochemistry, high-resolution digital elevation models, interferometric synthetic aperture radar (InSAR) and degassing surveys and compositions can be brought together to yield insights into the behavior of these and similar volcanic systems.

  15. Genome-wide association study identifies novel restless legs syndrome susceptibility loci on 2p14 and 16q12.1.

    PubMed

    Winkelmann, Juliane; Czamara, Darina; Schormair, Barbara; Knauf, Franziska; Schulte, Eva C; Trenkwalder, Claudia; Dauvilliers, Yves; Polo, Olli; Högl, Birgit; Berger, Klaus; Fuhs, Andrea; Gross, Nadine; Stiasny-Kolster, Karin; Oertel, Wolfgang; Bachmann, Cornelius G; Paulus, Walter; Xiong, Lan; Montplaisir, Jacques; Rouleau, Guy A; Fietze, Ingo; Vávrová, Jana; Kemlink, David; Sonka, Karel; Nevsimalova, Sona; Lin, Siong-Chi; Wszolek, Zbigniew; Vilariño-Güell, Carles; Farrer, Matthew J; Gschliesser, Viola; Frauscher, Birgit; Falkenstetter, Tina; Poewe, Werner; Allen, Richard P; Earley, Christopher J; Ondo, William G; Le, Wei-Dong; Spieler, Derek; Kaffe, Maria; Zimprich, Alexander; Kettunen, Johannes; Perola, Markus; Silander, Kaisa; Cournu-Rebeix, Isabelle; Francavilla, Marcella; Fontenille, Claire; Fontaine, Bertrand; Vodicka, Pavel; Prokisch, Holger; Lichtner, Peter; Peppard, Paul; Faraco, Juliette; Mignot, Emmanuel; Gieger, Christian; Illig, Thomas; Wichmann, H-Erich; Müller-Myhsok, Bertram; Meitinger, Thomas

    2011-07-01

    Restless legs syndrome (RLS) is a sensorimotor disorder with an age-dependent prevalence of up to 10% in the general population above 65 years of age. Affected individuals suffer from uncomfortable sensations and an urge to move in the lower limbs that occurs mainly in resting situations during the evening or at night. Moving the legs or walking leads to an improvement of symptoms. Concomitantly, patients report sleep disturbances with consequences such as reduced daytime functioning. We conducted a genome-wide association study (GWA) for RLS in 922 cases and 1,526 controls (using 301,406 SNPs) followed by a replication of 76 candidate SNPs in 3,935 cases and 5,754 controls, all of European ancestry. Herein, we identified six RLS susceptibility loci of genome-wide significance, two of them novel: an intergenic region on chromosome 2p14 (rs6747972, P = 9.03 × 10(-11), OR = 1.23) and a locus on 16q12.1 (rs3104767, P = 9.4 × 10(-19), OR = 1.35) in a linkage disequilibrium block of 140 kb containing the 5'-end of TOX3 and the adjacent non-coding RNA BC034767. PMID:21779176

  16. Prevalence of restless legs syndrome and sleep problems in Korean children and adolescents with attention deficit hyperactivity disorder: a single institution study

    PubMed Central

    Kwon, Soonhak; Sohn, Youngsoo; Jeong, Seong-Hoon; Chung, Un-Sun

    2014-01-01

    Purpose Attention deficit hyperactivity disorder (ADHD) is a common disorder in school-aged children. Patients with restless legs syndrome (RLS) often present with ADHD symptoms and vice versa. This study was the first to attempt to identify the prevalence of RLS and sleep problems in children with ADHD in Korea. Methods Patients diagnosed with ADHD were asked to complete a sleep questionnaire. The sleep questionnaire included items to help identify the presence of four typical symptoms that are used as diagnostic criteria for RLS. Results A total of 56 patients, including 51 boys and 5 girls (mean age, 10.7 years old) participated. Of these, 24 complained of pain, discomfort, or an unpleasant sensation in the legs. Based on the RLS diagnostic criteria, 2 patients were diagnosed with definite RLS and 4 with probable RLS. There were no significant differences in age, medication dosage, or neuropsychological test scores between the patients with and without RLS symptoms. Conclusion Approximately 42.9% of patients with ADHD presented with RLS symptoms and 7.1% of these were diagnosed with RLS. Patients with ADHD also experienced various other sleep disorders. Thus, appropriate assessment and treatment for sleep disorders in patients with ADHD is essential. PMID:25114692

  17. Spontaneous Low-Frequency Cerebral Hemodynamics Oscillations in Restless Legs Syndrome with Periodic Limb Movements During Sleep: A Near-Infrared Spectroscopy Study

    PubMed Central

    Byun, Jung-Ick; Lee, Gwan-Taek; Kim, Choong-Ki

    2016-01-01

    Background and Purpose Periodic limb movements (PLM) during sleep (PLMS) are associated with cortical and cardiovascular activation. Changes in cerebral hemodynamics caused by cortical activity can be measured using near-infrared spectroscopy (NIRS). We investigated oscillatory components of cerebral hemodynamics during PLM and different sleep stages in restless legs syndrome (RLS) patients with PLMS. Methods Four female RLS patients with PLMS, and four age- and sex-matched normal controls were included. PLM and sleep stages were scored using polysomnography, while the spontaneous cerebral hemodynamics was measured by NIRS. The phase and amplitude of the cerebral oxyhemoglobin concentration [HbO] and the deoxyhemoglobin concentration [Hb] low-frequency oscillations (LFOs) were evaluated during each sleep stage [waking, light sleep (LS; stages N1 and N2), slow-wave sleep (stage N3), and rapid eye movement (REM) sleep]. In RLS patients with PLMS, the cerebral hemodynamics during LS was divided into LS with and without PLM. Results The cerebral hemodynamics activity varied among the different sleep stages. There were changes in phase differences between [HbO] and [Hb] LFOs during the different sleep stages in the normal controls but not in the RLS patients with PLMS. The [HbO] and [Hb] LFO amplitudes were higher in the patient group than in controls during both LS with PLM and REM sleep. Conclusions The present study has demonstrated the presence of cerebral hemodynamics disturbances in RLS patients with PLMS, which may contribute to an increased risk of cerebrovascular events. PMID:26754783

  18. Current trends in the management of uremic restless legs syndrome: a systematic review on aspects related to quality of life, cardiovascular mortality and survival.

    PubMed

    Sakkas, Giorgos K; Giannaki, Christoforos D; Karatzaferi, Christina; Maridaki, Maria; Koutedakis, Yiannis; Hadjigeorgiou, Georgios M; Stefanidis, Ioannis

    2015-06-01

    Restless legs syndrome (RLS) affects almost one out of three end-stage renal disease patients. This review assesses the current treatment options for uremic RLS and the potential benefits of those treatments on quality of life parameters, cardiovascular mortality and survival. A systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. Fourteen studies met the inclusion criteria in which the international RLS study group criteria were used as the primary diagnostic tool. Both pharmacological and non-pharmacological approaches were found to reduce the severity of uremic RLS symptoms. Only four studies reported changes on aspects related to quality of life while those changes were also associated with health benefits that resulted in reduced cardiovascular risk. The severity of uremic RLS symptoms can be ameliorated by using dopamine agonists and gabapentin, intravenous iron, exercise or supplementation with vitamins C and E, although some of those treatment benefits may be transient. There is a lack of strong evidence regarding the effects of the pharmacological approaches on quality of life and cardiovascular survival and mortality. In contrast exercise has been proven beneficial in both reducing the RLS symptoms' severity score and improving the quality of life.

  19. NACRE II: an update of the NACRE compilation of charged-particle-induced thermonuclear reaction rates for nuclei with mass number A<16

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Takahashi, K.; Goriely, S.; Arnould, M.; Ohta, M.; Utsunomiya, H.

    2013-11-01

    An update of the NACRE compilation [3] is presented. This new compilation, referred to as NACRE II, reports thermonuclear reaction rates for 34 charged-particle induced, two-body exoergic reactions on nuclides with mass number A<16, of which fifteen are particle-transfer reactions and the rest radiative capture reactions. When compared with NACRE, NACRE II features in particular (1) the addition to the experimental data collected in NACRE of those reported later, preferentially in the major journals of the field by early 2013, and (2) the adoption of potential models as the primary tool for extrapolation to very low energies of astrophysical S-factors, with a systematic evaluation of uncertainties.

  20. FENIX (Fusion ENgineering International eXperimental): A test facility for ITER (International Thermonuclear Experimental Reactor) and other new superconducting magnets

    SciTech Connect

    Slack, D.S.; Patrick, R.E.; Miller, J.R.

    1990-09-21

    The Fusion ENgineering International eXperimental (FENIX) Test Facility which is nearing completion at Lawrence Livermore National Laboratory, is a 76-t set of superconducting magnets housed in a 4-m-diameter cryostat. It represents a significant step toward meeting the testing needs for the development of superconductors appropriate for large-scale magnet applications such as the International Thermonuclear Experimental Reactor (ITER). The magnet set is configured to allow radial access to the 0.4-m-diameter high-field region where maximum fields up to 14 T will be provided. The facility is fitted with a thermally isolated test well with a port to the high-field region that allows insertion and removal of test conductors without disturbing the cryogenic environment of the magnets. It is expected that the facility will be made available to magnet developers internationally, and this paper discusses its general design features, its construction, and its capabilities.

  1. The middle-long term prediction of the February 3, 1996 Lijiang earthquake (M S=7) by the ``criterion of activity in quiescence''

    NASA Astrophysics Data System (ADS)

    Zeng-Jian, Guo; Bao-Yan, Qin

    2000-07-01

    Earthquake activities in history are characterized by active and quiet periods. In the quiet period, the place where earthquake M S≥6 occurred means more elastic energy store and speedy energy accumulation there. When an active period of big earthquake activity appeared in wide region, in the place where earthquake (M S≥6) occurred in the past quiet period, the big earthquake with magnitude of 7 or more often occur there. We call the above-mentioned judgement for predicting big earthquake the “criterion of activity in quiescence”. The criterion is relatively effective for predicting location of big earthquake. In general, error of predicting epicenter is no more than 100 km. According to the criterion, we made successfully a middle-term prediction on the 1996 Lijiang earthquake in Yunnan Province, the error of predicted location is about 50 km. Besides, the 1994 Taiwan strait earthquake (M S=7.3), the 1995 Yunnan-Myanmar boundary earthquake (M S=7.2) and the Mani earthquake (M S=7.9) in north Tibet are accordant with the retrospective predictions by the “criterion of activity in quiescence”. The windows of “activity in quiescence” identified statistically by us are 1940 1945, 1958 1961 and 1979 1986. Using the “criterion of activity in quiescence” to predict big earthquake in the mainland of China, the earthquake defined by “activity in quiescence” has magnitude of 6 or more; For the Himalayas seismic belt, the Pacific seismic belt and the north-west boundary seismic belt of Xinjiang, the earthquake defined by “activity in quiescence” has magnitude of 7, which is corresponding to earthquake with magnitude of much more than 7 in future. For the regions where there are not tectonically and historically a possibility of occurring big earthquake (M S=7), the criterion of activity in quiescence is not effective.

  2. Retinoblastoma protein (pRb), but not p107 or p130, is required for maintenance of enterocyte quiescence and differentiation in small intestine.

    PubMed

    Guo, Jun; Longshore, Shannon; Nair, Rajalakshmi; Warner, Brad W

    2009-01-01

    The function of retinoblastoma protein (pRb) in the regulation of small intestine epithelial cell homeostasis has been challenged by several groups using various promoter-based Cre transgenic mouse lines. Interestingly, different pRb deletion systems yield dramatically disparate small intestinal phenotypes. These findings confound the function of pRb in this dynamic tissue. In this study, Villin-Cre transgenic mice were crossed with Rb (flox/flox) mice to conditionally delete pRb protein in small intestine enterocytes. We discovered a novel hyperplasia phenotype as well as ectopic cell cycle reentry within villus enterocytes in the small intestine. This phenotype was not seen in other pRb family member (p107 or p130) null mice. Using a newly developed crypt/villus isolation method, we uncovered that expression of pRb was undetectable, whereas proliferating cell nuclear antigen, p107, cyclin E, cyclin D3, Cdk2, and Cdc2 were dramatically increased in pRb-deficient villus cells. Cyclin A, cyclin D1, cyclin D2, and Cdk4/6 expression was not affected by absent pRb expression. pRb-deficient villus cells appeared capable of progressing to mitosis but with higher rates of apoptosis. However, the cycling villus enterocytes were not completely differentiated as gauged by significant reduction of intestinal fatty acid-binding protein expression. In summary, pRb, but not p107 or p130, is required for maintaining the postmitotic villus cell in quiescence, governing the expression of cell cycle regulatory proteins, and completing of absorptive enterocyte differentiation in the small intestine.

  3. EX Lupi FROM QUIESCENCE TO OUTBURST: EXPLORING THE LTE APPROACH IN MODELING BLENDED H{sub 2}O AND OH MID-INFRARED EMISSION

    SciTech Connect

    Banzatti, A.; Meyer, M. R.; Bruderer, S.; Geers, V.; Pascucci, I.; Lahuis, F.; Juhasz, A.; Henning, T.; Abraham, P.

    2012-01-20

    We present a comparison of archival Spitzer spectra of the strongly variable T Tauri EX Lupi, observed before and during its 2008 outburst. We analyze the mid-infrared emission from gas-phase molecules thought to originate in a circumstellar disk. In quiescence the emission shows a forest of H{sub 2}O lines, highly excited OH lines, and the Q branches of the organics C{sub 2}H{sub 2}, HCN, and CO{sub 2}, similar to the emission observed toward several T Tauri systems. The outburst emission shows instead remarkable changes: H{sub 2}O and OH line fluxes increase, new OH, H{sub 2}, and H I transitions are detected, and organics are no longer seen. We adopt a simple model of a single-temperature slab of gas in local thermal equilibrium, a common approach for molecular analyses of Spitzer spectra, and derive the excitation temperature, column density, and emitting area of H{sub 2}O and OH. We show how model results strongly depend on the selection of emission lines fitted and how this is likely to be attributed to a combination of non-thermal excitation and multiple emission components. Using H{sub 2}O lines that can be approximated as thermalized to a single temperature, our results are consistent with a column density decrease in outburst while the emitting area of warm gas increases. A rotation diagram analysis suggests that the OH emission can be explained with two temperature components, which remarkably increase in column density in outburst. The relative change of H{sub 2}O and OH emission suggests a key role for UV radiation in the disk surface chemistry.

  4. A clean sightline to quiescence: multiwavelength observations of the high Galactic latitude black hole X-ray binary Swift J1357.2-0933

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard M.; Gallo, Elena; Jonker, Peter G.; Miller-Jones, James C. A.; Homan, Jeroen; Muñoz-Darias, Teo; Markoff, Sera; Armas Padilla, Montserrat; Fender, Rob; Rushton, Anthony P.; Russell, David M.; Torres, Manuel A. P.

    2016-03-01

    We present coordinated multiwavelength observations of the high Galactic latitude (b = +50°) black hole X-ray binary (BHXB) Swift J1357.2-0933 in quiescence. Our broad-band spectrum includes strictly simultaneous radio and X-ray observations, and near-infrared, optical, and ultraviolet data taken 1-2 d later. We detect Swift J1357.2-0933 at all wavebands except for the radio (f5 GHz < 3.9 μJy beam-1; 3σrms). Given current constraints on the distance (2.3-6.3 kpc), its 0.5-10 keV X-ray flux corresponds to an Eddington ratio LX/LEdd = 4 × 10-9-3 × 10-8 (assuming a black hole mass of 10 M⊙). The broad-band spectrum is dominated by synchrotron radiation from a relativistic population of outflowing thermal electrons, which we argue to be a common signature of short-period quiescent BHXBs. Furthermore, we identify the frequency where the synchrotron radiation transitions from optically thick-to-thin (νb ≈ 2-5 × 1014 Hz), which is the most robust determination of a `jet break' for a quiescent BHXB to date. Our interpretation relies on the presence of steep curvature in the ultraviolet spectrum, a frequency window made observable by the low amount of interstellar absorption along the line of sight. High Galactic latitude systems like Swift J1357.2-0933 with clean ultraviolet sightlines are crucial for understanding black hole accretion at low luminosities.

  5. Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation.

    PubMed

    Garcia-Borreguero, Diego; Silber, Michael H; Winkelman, John W; Högl, Birgit; Bainbridge, Jacquelyn; Buchfuhrer, Mark; Hadjigeorgiou, Georgios; Inoue, Yuichi; Manconi, Mauro; Oertel, Wolfgang; Ondo, William; Winkelmann, Juliane; Allen, Richard P

    2016-05-01

    A Task Force was established by the International Restless Legs Syndrome Study Group (IRLSSG) in conjunction with the European Restless Legs Syndrome Study Group (EURLSSG) and the RLS Foundation (RLS-F) to develop evidence-based and consensus-based recommendations for the prevention and treatment of long-term pharmacologic treatment of dopaminergic-induced augmentation in restless legs syndrome/Willis-Ekbom disease (RLS/WED). The Task Force made the following prevention and treatment recommendations: As a means to prevent augmentation, medications such as α2δ ligands may be considered for initial RLS/WED treatment; these drugs are effective and have little risk of augmentation. Alternatively, if dopaminergic drugs are elected as initial treatment, then the daily dose should be as low as possible and not exceed that recommended for RLS/WED treatment. However, the physician should be aware that even low dose dopaminergics can cause augmentation. Patients with low iron stores should be given appropriate iron supplementation. Daily treatment by either medication should start only when symptoms have a significant impact on quality of life in terms of frequency and severity; intermittent treatment might be considered in intermediate cases. Treatment of existing augmentation should be initiated, where possible, with the elimination/correction of extrinsic exacerbating factors (iron levels, antidepressants, antihistamines, etc.). In cases of mild augmentation, dopamine agonist therapy can be continued by dividing or advancing the dose, or increasing the dose if there are breakthrough night-time symptoms. Alternatively, the patient can be switched to an α2δ ligand or rotigotine. For severe augmentation the patient can be switched either to an α2δ ligand or rotigotine, noting that rotigotine may also produce augmentation at higher doses with long-term use. In more severe cases of augmentation an opioid may be considered, bypassing α2δ ligands and rotigotine.

  6. Guidelines for the first-line treatment of restless legs syndrome/Willis-Ekbom disease, prevention and treatment of dopaminergic augmentation: a combined task force of the IRLSSG, EURLSSG, and the RLS-foundation.

    PubMed

    Garcia-Borreguero, Diego; Silber, Michael H; Winkelman, John W; Högl, Birgit; Bainbridge, Jacquelyn; Buchfuhrer, Mark; Hadjigeorgiou, Georgios; Inoue, Yuichi; Manconi, Mauro; Oertel, Wolfgang; Ondo, William; Winkelmann, Juliane; Allen, Richard P

    2016-05-01

    A Task Force was established by the International Restless Legs Syndrome Study Group (IRLSSG) in conjunction with the European Restless Legs Syndrome Study Group (EURLSSG) and the RLS Foundation (RLS-F) to develop evidence-based and consensus-based recommendations for the prevention and treatment of long-term pharmacologic treatment of dopaminergic-induced augmentation in restless legs syndrome/Willis-Ekbom disease (RLS/WED). The Task Force made the following prevention and treatment recommendations: As a means to prevent augmentation, medications such as α2δ ligands may be considered for initial RLS/WED treatment; these drugs are effective and have little risk of augmentation. Alternatively, if dopaminergic drugs are elected as initial treatment, then the daily dose should be as low as possible and not exceed that recommended for RLS/WED treatment. However, the physician should be aware that even low dose dopaminergics can cause augmentation. Patients with low iron stores should be given appropriate iron supplementation. Daily treatment by either medication should start only when symptoms have a significant impact on quality of life in terms of frequency and severity; intermittent treatment might be considered in intermediate cases. Treatment of existing augmentation should be initiated, where possible, with the elimination/correction of extrinsic exacerbating factors (iron levels, antidepressants, antihistamines, etc.). In cases of mild augmentation, dopamine agonist therapy can be continued by dividing or advancing the dose, or increasing the dose if there are breakthrough night-time symptoms. Alternatively, the patient can be switched to an α2δ ligand or rotigotine. For severe augmentation the patient can be switched either to an α2δ ligand or rotigotine, noting that rotigotine may also produce augmentation at higher doses with long-term use. In more severe cases of augmentation an opioid may be considered, bypassing α2δ ligands and rotigotine. PMID

  7. A Comparative Randomized Controlled Clinical Trial on the Effectiveness, Safety, and Tolerability of a Homeopathic Medicinal Product in Children with Sleep Disorders and Restlessness

    PubMed Central

    Jong, Miek C.; Ilyenko, Lydia; Kholodova, Irina; Verwer, Cynthia; Burkart, Julia; Weber, Stephan; Keller, Thomas; Klement, Petra

    2016-01-01

    A prospective, multicenter, randomized, open-label, controlled clinical trial was performed to evaluate the effectiveness and safety of the homeopathic product ZinCyp-3-02 in children with sleep disorders for ≥ one month compared to glycine. Children ≤ six years old received either ZinCyp-3-02 (N = 89) or comparator glycine (N = 90). After treatment for 28 days, total sleep-disorder-associated complaints severity scores decreased in both groups from median 7.0 (out of maximum 11.0) points to 2.0 (ZinCyp-3-02) and 4.0 (glycine) points, respectively, with overall higher odds of showing improvement for ZinCyp-3-02 (odds ratio: 4.45 (95% CI: 2.77–7.14), p < 0.0001, POM overall treatment related effect). Absence of individual complaints (time to sleep onset, difficulties maintaining sleep, sleep duration, troubled sleep (somniloquism), physical inactivity after awakening, restlessness for unknown reason, and sleep disorders frequency) at study end were significantly higher with ZinCyp-3-02 (all p values < 0.05). More children with ZinCyp-3-02 were totally free of complaints (p = 0.0258). Treatment effectiveness (p < 0.0001) and satisfaction assessments (p < 0.0001) were more favorable for ZinCyp-3-02. Few nonserious adverse drug reactions were reported (ZinCyp-3-02: N = 2, glycine: N = 1) and both treatments were well tolerated. Treatment with the homeopathic product ZinCyp-3-02 was found to be safe and superior to the comparator glycine in the treatment of sleep disorders in children. PMID:27242915

  8. A Comparative Randomized Controlled Clinical Trial on the Effectiveness, Safety, and Tolerability of a Homeopathic Medicinal Product in Children with Sleep Disorders and Restlessness.

    PubMed

    Jong, Miek C; Ilyenko, Lydia; Kholodova, Irina; Verwer, Cynthia; Burkart, Julia; Weber, Stephan; Keller, Thomas; Klement, Petra

    2016-01-01

    A prospective, multicenter, randomized, open-label, controlled clinical trial was performed to evaluate the effectiveness and safety of the homeopathic product ZinCyp-3-02 in children with sleep disorders for ≥ one month compared to glycine. Children ≤ six years old received either ZinCyp-3-02 (N = 89) or comparator glycine (N = 90). After treatment for 28 days, total sleep-disorder-associated complaints severity scores decreased in both groups from median 7.0 (out of maximum 11.0) points to 2.0 (ZinCyp-3-02) and 4.0 (glycine) points, respectively, with overall higher odds of showing improvement for ZinCyp-3-02 (odds ratio: 4.45 (95% CI: 2.77-7.14), p < 0.0001, POM overall treatment related effect). Absence of individual complaints (time to sleep onset, difficulties maintaining sleep, sleep duration, troubled sleep (somniloquism), physical inactivity after awakening, restlessness for unknown reason, and sleep disorders frequency) at study end were significantly higher with ZinCyp-3-02 (all p values < 0.05). More children with ZinCyp-3-02 were totally free of complaints (p = 0.0258). Treatment effectiveness (p < 0.0001) and satisfaction assessments (p < 0.0001) were more favorable for ZinCyp-3-02. Few nonserious adverse drug reactions were reported (ZinCyp-3-02: N = 2, glycine: N = 1) and both treatments were well tolerated. Treatment with the homeopathic product ZinCyp-3-02 was found to be safe and superior to the comparator glycine in the treatment of sleep disorders in children.

  9. Insulin-like growth factor 1 receptor and p38 mitogen-activated protein kinase signals inversely regulate signal transducer and activator of transcription 3 activity to control human dental pulp stem cell quiescence, propagation, and differentiation.

    PubMed

    Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre; Polakowska, Renata

    2014-04-15

    Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Y(low) stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

  10. The mass, radius, distance and cooling of the neutron star in EXO 0748-676 in quiescence with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Cheng, Zheng; Mendez, Mariano; Costantini, Elisa; Diaz Trigo, Maria

    2016-07-01

    We present the spectral analysis of four XMM-Newton observations of the neutron-star low-mass X-ray binary EXO 0748-676 in quiescence, taken between 2009 and 2013. We fit the spectra with an absorbed neutron-star atmosphere model, without the need for a high-energy (power-law) component, with a 95 per cent confidence upper limit of 1 per cent to the contribution of the power law to the total flux of the source in the 0.2-10.0 keV band. We find a significant emission line at around 0.5 keV in the spectra of the three CCD cameras on board XMM-Newton of all four observations; the line, which we tentatively identify as Lyα emission from NVII, is moderately broad, σ ≈ 0.17 keV, and contributes ˜10-14 per cent of the total flux in the 0.2-10 keV band. The temperature of the neutron star in EXO 0748-676 has decreased significantly compared to the previous XMM-Newton observation, with the cooling curve being consistent with either an exponential decay plus a constant, a power law or a broken power-law. We fitted the spectra with a neutron-star atmosphere model that takes into account the observed peak flux of photospheric radius expansion (PRE) bursts to constrain the neutron-star mass, radius and distance self-consistently. Using this model we carried out MCMC simulations assuming a uniform prior for the inclination angle of the system (which accounts for anisotropy in the emission at the peak of the bursts) and for the hydrogen fraction of the fuel during the PRE bursts. We find that M _{ns} = 1.87 ^{+0.69}_{-0.32} M⊙, R_{ns} = 8.5^{+3.2}_{-1.3} km and D = 5.4^{+2.4}_{-1.2} kpc (99% confidence level), which is inconsistent with quark-bearing equations of state for this neutron star.

  11. Traditional Chinese medicine herbal preparations in restless legs syndrome (RLS) treatment: a review and probable first description of RLS in 1529.

    PubMed

    Yan, Xue; Wang, Wei-Dong; Walters, Arthur S; Wang, Qi; Liu, Yan-Jiao; Chu, Fu-Yong

    2012-12-01

    Occidental medicine has a given definition for restless legs syndrome (RLS) and knowledge of RLS pathophysiology has led to the development of its therapeutic management. RLS has no cure. Many methods have been used for its treatment, among which traditional Chinese medicine (TCM) has been considered as a new approach. However, description and management of the disease symptoms can be found in Chinese ancient medical systems. The first mention of RLS may have been as early as the third century BC described as "leg uncomfortable". Nonetheless, the lack of a complete description encompassing all four modern cardinal features of RLS makes this uncertain. On the other hand, the first description of RLS encompassing three of the four major modern criteria occurs in the ancient book of Neike Zhaiyao (Internal summary), 1529 AD just about a century and a half prior to the description of RLS by Sir Thomas Willis in England. Here, we introduce the philosophical concepts of traditional Chinese medicine and the description, classification and understanding of RLS symptoms in traditional Chinese medicine. We have conducted an in-depth review of the literature reporting one part of TCM, Chinese herbal treatment efficacy for RLS, through both English and Chinese search engines. Eighty-five studies were included in the review and more than 40 formulas (including 176 different ingredients) were found in the literature. According to the literature, Chinese herbs have been demonstrated to be safe and hold great potential to be an effective treatment modality for RLS, but the evidence is limited by the quality of these studies. Of the eighty-five studies, only nine were clinical trials with a control group and only three of them were randomized. In cases where herbal preparations were compared to Western medications for RLS, the herbal preparations appear to be superior. However, uncertainty as to whether the diagnosis of RLS was made in accord with Western norms and the use of

  12. Effect of particle pinch on the fusion performance and profile features of an international thermonuclear experimental reactor-like fusion reactor

    NASA Astrophysics Data System (ADS)

    Wang, Shijia; Wang, Shaojie

    2015-04-01

    The evolution of the plasma temperature and density in an international thermonuclear experimental reactor (ITER)-like fusion device has been studied by numerically solving the energy transport equation coupled with the particle transport equation. The effect of particle pinch, which depends on the magnetic curvature and the safety factor, has been taken into account. The plasma is primarily heated by the alpha particles which are produced by the deuterium-tritium fusion reactions. A semi-empirical method, which adopts the ITERH-98P(y,2) scaling law, has been used to evaluate the transport coefficients. The fusion performances (the fusion energy gain factor, Q) similar to the ITER inductive scenario and non-inductive scenario (with reversed magnetic shear) are obtained. It is shown that the particle pinch has significant effects on the fusion performance and profiles of a fusion reactor. When the volume-averaged density is fixed, particle pinch can lower the pedestal density by ˜30 % , with the Q value and the central pressure almost unchanged. When the particle source or the pedestal density is fixed, the particle pinch can significantly enhance the Q value by 60 % , with the central pressure also significantly raised.

  13. Effect of particle pinch on the fusion performance and profile features of an international thermonuclear experimental reactor-like fusion reactor

    SciTech Connect

    Wang, Shijia Wang, Shaojie

    2015-04-15

    The evolution of the plasma temperature and density in an international thermonuclear experimental reactor (ITER)-like fusion device has been studied by numerically solving the energy transport equation coupled with the particle transport equation. The effect of particle pinch, which depends on the magnetic curvature and the safety factor, has been taken into account. The plasma is primarily heated by the alpha particles which are produced by the deuterium-tritium fusion reactions. A semi-empirical method, which adopts the ITERH-98P(y,2) scaling law, has been used to evaluate the transport coefficients. The fusion performances (the fusion energy gain factor, Q) similar to the ITER inductive scenario and non-inductive scenario (with reversed magnetic shear) are obtained. It is shown that the particle pinch has significant effects on the fusion performance and profiles of a fusion reactor. When the volume-averaged density is fixed, particle pinch can lower the pedestal density by ∼30%, with the Q value and the central pressure almost unchanged. When the particle source or the pedestal density is fixed, the particle pinch can significantly enhance the Q value by  60%, with the central pressure also significantly raised.

  14. Spectroscopy of 19Ne for the thermonuclear 15O(α ,γ )19Ne and 18F(p ,α )15O reaction rates

    NASA Astrophysics Data System (ADS)

    Parikh, A.; Laird, A. M.; de Séréville, N.; Wimmer, K.; Faestermann, T.; Hertenberger, R.; Seiler, D.; Wirth, H.-F.; Adsley, P.; Fulton, B. R.; Hammache, F.; Kiener, J.; Stefan, I.

    2015-11-01

    Uncertainties in the thermonuclear rates of the 15O (α ,γ ) 19 Ne and 18 F(p ,α ) 15 O reactions affect model predictions of light curves from type I x-ray bursts and the amount of the observable radioisotope 18F produced in classical novae, respectively. To address these uncertainties, we have studied the nuclear structure of 19Ne over Ex=4.0 -5.1 and 6.1-7.3 MeV using the (3He19F,t )19Ne reaction. We find the Jπ values of the 4.14- and 4.20-MeV levels to be consistent with 9 /2- and 7 /2- , respectively, in contrast to previous assumptions. We confirm the recently observed triplet of states around 6.4 MeV and find evidence that the state at 6.29 MeV, just below the proton threshold, is either broad or a doublet. Our data also suggest that predicted but yet unobserved levels may exist near the 6.86-MeV state. Higher resolution experiments are urgently needed to further clarify the structure of 19Ne around the proton threshold before a reliable 18 F(p ,α ) 15 O rate for nova models can be determined.

  15. Investigation of the thermonuclear 18Ne(α,p)21Na reaction rate via resonant elastic scattering of 21Na + p

    NASA Astrophysics Data System (ADS)

    Zhang, L. Y.; He, J. J.; Parikh, A.; Xu, S. W.; Yamaguchi, H.; Kahl, D.; Kubono, S.; Mohr, P.; Hu, J.; Ma, P.; Chen, S. Z.; Wakabayashi, Y.; Wang, H. W.; Tian, W. D.; Chen, R. F.; Guo, B.; Hashimoto, T.; Togano, Y.; Hayakawa, S.; Teranishi, T.; Iwasa, N.; Yamada, T.; Komatsubara, T.; Zhang, Y. H.; Zhou, X. H.

    2014-01-01

    The 18Ne(α,p)21Na reaction is thought to be one of the key breakout reactions from the hot CNO cycles to the rp process in type I x-ray bursts. In this work, the resonant properties of the compound nucleus 22Mg have been investigated by measuring the resonant elastic scattering of 21Na + p. An 89-MeV 21Na radioactive beam delivered from the CNS Radioactive Ion Beam Separator bombarded an 8.8 mg/cm2 thick polyethylene (CH2)n target. The 21Na beam intensity was about 2×105 pps, with a purity of about 70% on target. The recoiled protons were measured at the center-of-mass scattering angles of θc.m.≈175.2∘, 152.2∘, and 150.5∘ by three sets of ΔE-E telescopes, respectively. The excitation function was obtained with the thick-target method over energies Ex(22Mg)=5.5-9.2 MeV. In total, 23 states above the proton-threshold in 22Mg were observed, and their resonant parameters were determined via an R-matrix analysis of the excitation functions. We have made several new Jπ assignments and confirmed some tentative assignments made in previous work. The thermonuclear 18Ne(α,p)21Na rate has been recalculated based on our recommended spin-parity assignments. The astrophysical impact of our new rate has been investigated through one-zone postprocessing x-ray burst calculations. We find that the 18Ne(α,p)21Na rate significantly affects the peak nuclear energy generation rate, reaction fluxes, and onset temperature of this breakout reaction in these astrophysical phenomena.

  16. Development of a Jones vector based model for the measurement of a plasma current in a thermonuclear fusion reactor with a POTDR setup

    NASA Astrophysics Data System (ADS)

    Aerssens, M.; Gusarov, A.; Moreau, P.; Malard, P.; Massaut, V.; Mégret, P.; Wuilpart, M.

    2012-04-01

    Fibre optical current sensor (FOCS) is a promising alternative to inductive sensors for the measurement of the plasma current in future thermonuclear fusion reactors. Standard FOCS relies on the measurement of the state of polarisation (SOP) of light at the output of an optical bre surrounding a current. Because of the Faraday eect, magnetic eld induced by electrical current rotates the SOP of light travelling into the bre. According to the Ampere's theorem this rotation is proportional to the surrounded current. In future tokamaks like ITER and DEMO, the plasma current will be suciently high to generate a rotation of the SOP higher than 2 radians. These conditions may lead to uncertainties on the determination of the plasma current if no post processing is performed. In this paper we propose a solution with a Polarisation Optical Time Domain Re ectometer (POTDR) setup allowing both unambiguous plasma current measurement and also local magnetic eld measurements. This measurement is based on the assessment of the SOP rotation of the Rayleigh backscattered POTDR signal. Thanks to the presence of an input polarizer, SOP variations are converted into power uctuations that contain information about the distribution of the magnetic eld and therefore about the plasma current. Using the Jones formalism we have developed a model accounting for the modication of the SOP of light travelling into the optical bre and the evolution of the POTDR signal. In parallel experimental PODTR measurements have been performed on the Tore Supra tokamak situated at CEA Cadarache in France. A comparison between the models and the experimental results conrms the capability of the system to measure the plasma current and the local magnetic eld even if further data post processing are still required.

  17. Thermonuclear X-ray bursts from the 401-Hz accreting pulsar IGR J17498-2921: indication of burning in confined regions

    NASA Astrophysics Data System (ADS)

    Chakraborty, Manoneeta; Bhattacharyya, Sudip

    2012-05-01

    We use the 2011 Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the 401-Hz accreting pulsar and burster IGR J17498-2921 to perform timing analysis and time-resolved spectroscopy of 12 thermonuclear X-ray bursts. We confirm previously reported burst oscillations from this source with a much higher significance (8.8σ). We note that the bursts can be divided into three groups: big photospheric radius expansion (PRE) bursts are about 10 times more luminous than medium bursts, while the latter are about 10 times more luminous than small bursts. The PCA field of view of these observations contains several known bursters, and hence some of the observed bursts might not be from IGR J17498-2921. The oscillations during big bursts at the known pulsar frequency show that these bursts were definitely from IGR J17498-2921. We find that at least several of the other bursts were also likely originated from IGR J17498-2921. Spectral analysis reveals that the luminosity differences among various bursts are primarily due to differences in normalizations, and not temperatures, even when we consider the effects of colour factor. This shows burning on a fraction of the stellar surface for those small and medium bursts, which originated from IGR J17498-2921. The low values of the upper limits of burst oscillation amplitude for these bursts suggest a small angle between the spin axis and the magnetic axis. We find indications of the PRE nature of a medium burst, which likely originated from IGR J17498-2921. If true, then, to the best of our knowledge, this is the first time that two PRE bursts with a peak count rate ratio of as high as ≈12 have been detected from the same source.

  18. Restless rays, steady wave fronts.

    PubMed

    Godin, Oleg A

    2007-12-01

    Observations of underwater acoustic fields with vertical line arrays and numerical simulations of long-range sound propagation in an ocean perturbed by internal gravity waves indicate that acoustic wave fronts are much more stable than the rays comprising these wave fronts. This paper provides a theoretical explanation of the phenomenon of wave front stability in a medium with weak sound-speed perturbations. It is shown analytically that at propagation ranges that are large compared to the correlation length of the sound-speed perturbations but smaller than ranges at which ray chaos develops, end points of rays launched from a point source and having a given travel time are scattered primarily along the wave front corresponding to the same travel time in the unperturbed environment. The ratio of root mean square displacements of the ray end points along and across the unperturbed wave front increases with range as the ratio of ray length to correlation length of environmental perturbations. An intuitive physical explanation of the theoretical results is proposed. The relative stability of wave fronts compared to rays is shown to follow from Fermat's principle and dimensional considerations. PMID:18247745

  19. Homelessness, Restlessness and Diasporic Poetry

    ERIC Educational Resources Information Center

    Kizel, Arie

    2010-01-01

    Can poetry be Diasporic? Can poetry free itself from the shackles of conformism? Can it be independent and divergent, and not seek a home? Is it capable of mustering its inner strengths and living without being enlisted by a collective that accords it power? This article argues that poetry is essentially dialectic. It has little vitality without…

  20. Detection of precursory slips on a fault by the quiescence and activation of seismicity relative to the ETAS model and by the anomalous trend of the geodetic time series of distances between GPS stations around the fault

    NASA Astrophysics Data System (ADS)

    Ogata, Y.

    2006-12-01

    This paper is concerned with the detection of precursory slip on a rupturing fault, supported by both seismic and geodetic records. Basically, the detection relies on the principle that, assuming precursory slip on the rupturing fault, the seismic activity around the fault should be enhanced or reduced in the zones where increment of the Coulomb failure stress (CFS) is positive or negative, respectively. However, any occurring event also affects the stress changes in neighboring regions, which can trigger further aftershock clusters. Whereas such stress transfers are too difficult to be computed precisely, due to the unknown complex fault system, the ordinary short-term occurrence rate of earthquakes in a region is easily predicted using the ETAS model of triggering seismicity; and any anomalous seismic activity, such as quiescence and activation, can be quantified by identifying a significant deviation from the predicted rate. Such anomalies are revealed to have occurred during several years leading up to the 2004 Chuetsu Earthquake of M6.8, central Honshu, and also the 2005 Western Fukuoka-Ken-Oki Earthquake of M7.0, Kyushu, Japan. Quiescence and activation in the regions coincided with negative and positive increments of the CFS, respectively, and were probably transferred from possible aseismic slips on the focal fault plane. Such slips are further supported by transient crustal movement around the source preceding the rupture. Time series records of the baseline distances between the permanent GPS stations deviated from the predicted trends, with the deviations consistent with the coseismic horizontal displacements of the stations due to these earthquakes. References Ogata, Y. (2006) Report of the Coordinating Committee for Earthquake Prediction, 76 (to appear, in Japanese).