WorldWideScience

Sample records for rapid onset acceleration

  1. Rapid onset aggressive vertebral haemangioma.

    Science.gov (United States)

    Cheung, Nicholas K; Doorenbosch, Xenia; Christie, John G

    2011-03-01

    Vertebral haemangiomas are generally benign asymptomatic vascular tumours seen commonly in the adult population. Presentations in paediatric populations are extremely rare, which can result in rapid onset of neurological symptoms. We present a highly unusual case of an aggressive paediatric vertebral haemangioma causing significant cord compression. A 13-year-old boy presented with only 2 weeks duration of progressive gait disturbance, truncal ataxia and loss of bladder control. Magnetic resonance imaging (MRI) of the spine revealed a large vascular epidural mass extending between T6 and T8 vertebral bodies. Associated displacement and compression of the spinal cord was present. A highly vascular bony lesion was found during surgery. Histopathology identified this tumour to be a vertebral haemangioma. We present an extremely unusual acute presentation of a paediatric vertebral haemangioma. This study highlights the need for early diagnosis, MRI for investigation and urgent surgical management. © Springer-Verlag 2011

  2. Western equine encephalitis with rapid onset of parkinsonism.

    Science.gov (United States)

    Schultz, D R; Barthal, J S; Garrett, G

    1977-11-01

    A patient with confirmed western equine encephalitis had the rapid onset of postencephalitic parkinsonian sequelae. This observation corroborates similar previous but rare reports. Response to therapy with levodopa, dopa decarboxylase inhibitor, and trihexyphenidyl was dramatic. However, remission maintained for 12 months without medication suggests that the parkinsonism would have remitted spontaneously. In either case, this has not previously been reported with the western equine togavirus.

  3. Rapid onset of efficacy of rasagiline in early Parkinson's disease.

    Science.gov (United States)

    Zambito Marsala, Sandro; Vitaliani, Roberta; Volpe, Daniele; Capozzoli, Francesca; Baroni, Luciana; Belgrado, Enrico; Borsato, Carlo; Gioulis, Manuela; Marchini, Corrado; Antonini, Angelo

    2013-11-01

    Rasagiline is a monoamine oxidase type-B inhibitor used as monotherapy or in addition to levodopa in the treatment of Parkinson's disease (PD). This naturalistic single-blind study was aimed at evaluating the rapidity of onset effect of rasagiline on motor symptoms in a cohort of early relatively elderly PD patients. 102 outpatients (55 males, median age 71 years) have been selected: 26 were PD therapy-naive and 76 received rasagiline as add-on therapy. The third section of the Unified Parkinson's Disease Rating Scale (UPDRSIII) and the Hoehn-Yahr (HY) scale were assessed at baseline and after 1 and 4 weeks thereafter. The mean UPDRS III total score (-6.7 at week 1 and -8.9 at week 4) and single items, as well as mean HY score (-0.40 at week 1 and -0.67 at week 4), significantly decreased from baseline (p or ≤71 years. Rasagiline had a rapid therapeutic effect from the first week of therapy, which further improved at 4 weeks. The rapid onset of action and the absence of a dose titration are important issues in the management of the PD patient.

  4. Priming with Rocuronium to Accelerate the Onset Time of Cisatracurium During Intubation

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    Shih-Pin Lin

    2009-01-01

    Conclusion: Priming with rocuronium or cisatracurium for 3 minutes significantly accelerated the onset of cisatracurium. Priming with rocuronium for 3 minutes improved the onset time of cisatracurium even more than priming with cisatracurium itself.

  5. Rapid Onset Acute Epiglottitis Leading to Negative Pressure Pulmonary Edema

    Directory of Open Access Journals (Sweden)

    V Saraswat

    2007-01-01

    Full Text Available Pulmonary edema is a potentially life-threatening complication of acute airway obstruction. It develops rapidly, without warning, in young healthy individuals. Two forms of post-obstructive pulmonary edema (POPE (also known as negative pressure pulmonary edema, NPPE have been identified. POPE I follows sudden, severe upper airway obstruction. POPE II occurs following surgical relief of chronic upper airway obstruction. Treatment for both is supportive. Full and rapid recovery can be expected with appropriate management. A case report of a middle aged man with acute onset epiglottitis who developed negative pressure pulmonary edema after intubation is presented. The report includes a brief discussion on etiology, clinical features and management dilemma of acute upper airway obstruction.

  6. Acute renal response to rapid onset respiratory acidosis.

    Science.gov (United States)

    Ramadoss, Jayanth; Stewart, Randolph H; Cudd, Timothy A

    2011-03-01

    Renal strong ion compensation to chronic respiratory acidosis has been established, but the nature of the response to acute respiratory acidosis is not well defined. We hypothesized that the response to acute respiratory acidosis in sheep is a rapid increase in the difference in renal fractional excretions of chloride and sodium (Fe(Cl) - Fe(Na)). Inspired CO(2) concentrations were increased for 1 h to significantly alter P(a)CO(2) and pH(a) from 32 ± 1 mm Hg and 7.52 ± 0.02 to 74 ± 2 mm Hg and 7.22 ± 0.02, respectively. Fe(Cl) - Fe(Na) increased significantly from 0.372 ± 0.206 to 1.240 ± 0.217% and returned to baseline at 2 h when P(a)CO(2) and pH(a) were 37 ± 0.6 mm Hg and 7.49 ± 0.01, respectively. Arterial pH and Fe(Cl) - Fe(Na) were significantly correlated. We conclude that the kidney responds rapidly to acute respiratory acidosis, within 30 min of onset, by differential reabsorption of sodium and chloride.

  7. Adult-onset phenylketonuria with rapidly progressive dementia and parkinsonism.

    Science.gov (United States)

    Tufekcioglu, Zeynep; Cakar, Arman; Bilgic, Basar; Hanagasi, Hasmet; Gurvit, Hakan; Emre, Murat

    2016-06-01

    Phenylketonuria (PKU) is an autosomal recessive metabolic disorder due to mutations in the phenylalanine hydroxylase (PAH) gene, which converts phenylalanine (PHE) to tyrosine. Although it is principally a childhood disorder, in rare cases, the first signs of PKU may develop in late adulthood resembling common neurological diseases. Here we report a 59-year-old, previously normal functioning man who was admitted with blurred vision, cognitive problems, and gait difficulty that began 8 months before. He had brisk reflexes and left side dominant parkinsonism. His Mini-Mental State Examination (MMSE) score was 25/30, and neuropsychological evaluation revealed a dysexecutive syndrome with simultanagnosia and constructional apraxia. His Clinical Dementia Rating score (CDR) was 1. Cranial MRI revealed bilateral diffuse hyperintense lesions in parietal and occipital white matter in T2, fluid-attenuated inversion recovery, and diffusion weighted images. Diagnostic workup for rapidly progressive dementias was all normal except PHE level which was found to be highly elevated (1075 μmol/L, normal 39-240 μmol/L) with normal tyrosine level (61.20 μmol/L, normal 35-100 μmol/L). Three months after PHE-restricted diet, his cognitive impairment and signs of parkinsonism significantly improved, with MRI scan unchanged. This case demonstrates that late-onset PKU is a rare, treatable cause of rapidly progressive dementia and parkinsonism with certain constellations such as consanguinity and white matter abnormalities (WMAs) in imaging.

  8. Neuromuscular Control of Rapid Linear Accelerations in Fish

    Science.gov (United States)

    2016-06-22

    sunfish, Lepomis macrochirus. Animals with flexible bodies, like fishes , face a tradeoff for rapid movements. To produce high forces, they must...2014 30-Apr-2015 Approved for Public Release; Distribution Unlimited Final Report: Neuromuscular Control of Rapid Linear Accelerations in Fish The...Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 swimming, acceleration, fish , muscle, stiffness REPORT DOCUMENTATION PAGE 11. SPONSOR

  9. Semantic Congruence Accelerates the Onset of the Neural Signals of Successful Memory Encoding.

    Science.gov (United States)

    Packard, Pau A; Rodríguez-Fornells, Antoni; Bunzeck, Nico; Nicolás, Berta; de Diego-Balaguer, Ruth; Fuentemilla, Lluís

    2017-01-11

    As the stream of experience unfolds, our memory system rapidly transforms current inputs into long-lasting meaningful memories. A putative neural mechanism that strongly influences how input elements are transformed into meaningful memory codes relies on the ability to integrate them with existing structures of knowledge or schemas. However, it is not yet clear whether schema-related integration neural mechanisms occur during online encoding. In the current investigation, we examined the encoding-dependent nature of this phenomenon in humans. We showed that actively integrating words with congruent semantic information provided by a category cue enhances memory for words and increases false recall. The memory effect of such active integration with congruent information was robust, even with an interference task occurring right after each encoding word list. In addition, via electroencephalography, we show in 2 separate studies that the onset of the neural signals of successful encoding appeared early (∼400 ms) during the encoding of congruent words. That the neural signals of successful encoding of congruent and incongruent information followed similarly ∼200 ms later suggests that this earlier neural response contributed to memory formation. We propose that the encoding of events that are congruent with readily available contextual semantics can trigger an accelerated onset of the neural mechanisms, supporting the integration of semantic information with the event input. This faster onset would result in a long-lasting and meaningful memory trace for the event but, at the same time, make it difficult to distinguish it from plausible but never encoded events (i.e., related false memories). Conceptual or schema congruence has a strong influence on long-term memory. However, the question of whether schema-related integration neural mechanisms occur during online encoding has yet to be clarified. We investigated the neural mechanisms reflecting how the active

  10. Rapid Onset Acute Epiglottitis Leading to Negative Pressure Pulmonary Edema

    OpenAIRE

    V Saraswat; P V Madhu; Suresh S Kumar

    2007-01-01

    Pulmonary edema is a potentially life-threatening complication of acute airway obstruction. It develops rapidly, without warning, in young healthy individuals. Two forms of post-obstructive pulmonary edema (POPE) (also known as negative pressure pulmonary edema, NPPE) have been identified. POPE I follows sudden, severe upper airway obstruction. POPE II occurs following surgical relief of chronic upper airway obstruction. Treatment for both is supportive. Full and rapid recovery can be expecte...

  11. Prevention and treatment of traumatic brain injury due to rapid-onset natural disasters

    Directory of Open Access Journals (Sweden)

    James L. Regens

    2014-04-01

    Full Text Available The prevention and treatment of traumatic brain injury (TBI attributable to rapid-onset natural disasters is a major challenge confronting disaster preparedness planners and emergency medical personnel responding to those incidents. The kinetic energy released by rapid-onset natural disasters such as earthquakes, hurricanes or typhoons, and tornadoes can cause mild, moderate or severe TBIs. As a result, neurotrauma is a major risk factor for mortality and morbidity outcomes within the spatial domain impacted by a rapid-onset natural disaster. This review article elucidates major challenges associated with immediate emergency medical response, long-term care, and prevention of post-event increases in pediatric TBIs because of child abuse when rapid-onset natural disasters occur.

  12. The Correlation between Clinical Variables and Sleep Onset Rapid Eye Movement Period Frequencies in Narcoleptic Patients

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    Jin Hwa Jeong

    2010-11-01

    Full Text Available Background and Objective A diagnosis of narcolepsy is defined by less than 8 minutes of mean sleep latency, and two or more sleep onset rapid eye movement periods on the Multiple Sleep Latency Test. This study examined the relationship between the sleep onset rapid eye movement period frequencies during Multiple Sleep Latency Test and narcoleptic symptom severity. Methods From March 2004 to August 2009, 126 patients suffering from excessive daytime sleepiness who visited the Sleep Disorders Clinic of St. Vincent’s Hospital at the Catholic University of Korea were tested by polysomnography and Multiple Sleep Latency Test. Subjects were divided into three groups according to the number of sleep onset rapid eye movement periods that appeared on the Multiple Sleep Latency Test. Symptom severity instruments included the Epworth Sleepiness Scale and the Stanford Center for Narcolepsy Sleep Inventory, and various sleep parameters. In addition, we performed human leukocyte antigen genotyping for human leukocyte antigen-DQB1*0602 on all patients. Results Among the three groups classified by the number of sleep onset rapid eye movement periods during Multiple Sleep Latency Test, we found no significant differences in demographic features, Epworth Sleepiness Scale, and most polysomnographic findings. However, we observed cataplexy, hypnagogic hallucination, sleep paralysis, and human leukocyte antigen-DQB1*0602 positivity more frequently in groups with higher sleep onset rapid eye movement period frequencies. In addition, the proportions of stage II sleep, REM sleep latency from polysomnography, and mean sleep latency and mean REM sleep latency from the Multiple Sleep Latency Test significantly decreased with increasing sleep onset rapid eye movement period frequency. Conclusions In this study, we demonstrated that sleep onset rapid eye movement period frequency during Multiple Sleep Latency Test correlated with sleep architecture, daytime symptom

  13. Identifying the Onset of Congestion Rapidly with Existing Traffic Detectors

    OpenAIRE

    Coifman, Benjamin

    1999-01-01

    From an operations standpoint, the most important task of a traffic surveillance system is determining reliably whether the facility is free flowing or congested. The second most important task is responding rapidly when the facility becomes congested. Other tasks, such as quantifying the magnitude of congestion, are desirable, but tertiary. To address the first two tasks, this paper presents a new approach for traffic surveillance using existing detectors. Rather than expending a considerabl...

  14. Pharmacological interventions for acceleration of the onset time of rocuronium: a meta-analysis.

    Science.gov (United States)

    Dong, Jing; Gao, Lingqi; Lu, Wenqing; Xu, Zifeng; Zheng, Jijian

    2014-01-01

    Rocuronium is an acceptable alternative when succinylcholine is contraindicated for facilitating the endotracheal intubation. However, the onset time of rocuronium for good intubation condition is still slower than that condition of succinylcholine. This study systematically investigated the most efficacious pharmacological interventions for accelerating the onset time of rocuronium. Medline, Embase, Cochrane Library databases, www.clinicaltrials.gov, and hand searching from the reference lists of identified papers were searched for randomized controlled trials comparing drug interventions with placebo or another drug to shorten the onset time of rocuronium. Statistical analyses were performed using RevMan5.2 and ADDIS 1.16.5 softwares. Mean differences (MDs) with their 95% confidence intervals (95% CIs) were used to analyze the effects of drug interventions on the onset time of rocuronium. 43 randomized controlled trials with 2,465 patients were analyzed. The average onset time of rocuronium was 102.4±24.9 s. Priming with rocuronium [Mean difference (MD) -21.0 s, 95% confidence interval (95% CI) (-27.6 to -14.3 s)], pretreatment with ephedrine [-22.3 s (-29.1 to -15.5 s)], pretreatment with magnesium sulphate [-28.2 s (-50.9 to -5.6 s)] were all effective in reducing the onset time of rocuronium. Statistical testing of indirect comparisons showed that rocuronium priming, pretreatment with ephedrine, and pretreatment with magnesium sulphate had the similar efficacy. Rocuronium priming, pretreatment with ephedrine, and pretreatment with magnesium sulphate were all effective in accelerating the onset time of rocuronium, and furthermore their efficacies were similar. Considering the convenience and efficacy, priming with rocuronium is recommended for accelerating the onset time of rocuronium. However, more strict clinical trials are still needed to reach a more solid conclusion due to the large heterogeneities exist among different studies.

  15. Onset and effectiveness of rocuronium for rapid onset of paralysis in patients with major burns: priming or large bolus

    Science.gov (United States)

    Han, T.-H.; Martyn, J. A. J.

    2009-01-01

    Background Burn injury leads to resistance to the effects of non-depolarizing muscle relaxants. We tested the hypothesis that a larger bolus dose is as effective as priming for rapid onset of paralysis after burns. Methods Ninety adults, aged 18–59 yr with 40 (2)% [mean (se)] burn and 30 (2) days after injury, received rocuronium as a priming dose followed by bolus (0.06+0.94 mg kg−1), or single bolus of either 1.0 or 1.5 mg kg−1. Sixty-one non-burned, receiving 1.0 mg kg−1 as a primed (0.06+0.94 mg kg−1) or full bolus dose, served as controls. Acceleromyography measured the onset times. Results Priming when compared with 1.0 mg kg−1 bolus in burned patients shortened the time to first appearance of twitch depression (30 vs 45 s, P<0.05) and time to maximum twitch inhibition (135 vs 210 s, P<0.05). The onset times between priming and higher bolus dose (1.5 mg kg−1) were not different (30 vs 30 s for first twitch depression and 135 vs 135 s for maximal depression, respectively). The onset times in controls, however, were significantly (P<0.05) faster than burns both for priming and for full bolus (15 and 15 s, respectively, for first twitch depression and 75 and 75 s for maximal depression). Priming caused respiratory distress in 10% of patients in both groups. Intubating conditions in burns were significantly better with 1.5 mg kg−1 than with priming or full 1.0 mg kg−1 bolus. Conclusions A dose of 1.5 mg kg−1 not only produces an initial onset of paralysis as early as 30 s, which we speculate could be a reasonable onset time for relief of laryngospasm, but also has an onset as fast as priming with superior intubating conditions and no respiratory side-effects. PMID:19029093

  16. Characteristics of Four SPE Classes According to Onset Timing and Proton Acceleration Patterns

    Science.gov (United States)

    Kim, Roksoon

    2015-04-01

    In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low ( ~1 Rs) and close to the western limb, while the latter has a relatively higher (mean=6.05 Rs) and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux (mean=327 pfu) in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.

  17. RAPIDE 0.0 RHIC Accelerator Physics Intrepid Development Environment

    Energy Technology Data Exchange (ETDEWEB)

    Satogata, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Saltmarsh, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    1993-08-01

    This document is a guide to the common environmental features of computing in (and around) the RHIC Accelerator Physics.sectio on the 'zoo' cluster of UNJX workstations, in RAPIDE, the RHIC Accelerator Physics Intrepid Development Environment It is hoped tliat later revisions of this document will approach a more professional 'style guide', beyond the convenient collection of pointers and hints presented here. RAP does two kinds of computing, "controls" and "general", addressed in sections 2 and 3 of this document For general computing, efficient system administration requires cooperation in using a common environment There is a much stronger need to define - and adhere to - a commonly agreed set of styles (or rules) in developing controls software. Right now, these rules have been set "de facto". Future improvements to the controls environment, particularly in response to the opinions of users, depends on broad knowledge of what the rules are. There are environmental issues that are basic to both controls and general computing, and that are so fundamental that they are (almost) unarguable. They are described immediately below, in the next section.

  18. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    Science.gov (United States)

    Chang, Jefferson C.; Lockner, David A.; Reches, Z.

    2012-01-01

    After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

  19. Rapid onset of rhabdomyolysis after switching to a raltegravir-based antiretroviral regimen.

    Science.gov (United States)

    Tsai, Wan-Jung; Lee, Susan Shin-Jung; Tsai, Hung-Chin; Sy, Cheng-Len; Chen, Jui-Kuang; Wu, Kuang-Sheng; Wang, Yung-Hsin; Chen, Yao-Shen

    2016-04-01

    Raltegravir is the first integrase inhibitor antiretroviral agent that has been demonstrated to have antiviral efficacy and safety. However, the US Food and Drug Administration has recommended use with caution in patients with risk factors for rhabdomyolysis, based on four case reports of rhabdomyolysis in patients with identifiable risk factors. We present a 32-year-old Asian man with human immunodeficiency virus (HIV), but without other underlying diseases, who developed rapid-onset, raltegravir-associated rhabdomyolysis and hyperlactatemia. Our patient lacked predisposing factors for rhabdomyolysis, and the rapid onset time of 4 days was the shortest reported. Therefore, clinicians should exercise caution when using raltegravir and closely monitor all patients for the symptoms of muscle pain and weakness. This case has been reported to the National Adverse Drug Reactions Reporting System of the Department of Health in Taiwan. Copyright © 2013. Published by Elsevier B.V.

  20. Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) Syndrome: A Case Report

    OpenAIRE

    Bagheri; Pourbakhtyaran; Talebi Kiasari; Taherkhanchi; Salarian; Sadeghi

    2016-01-01

    Introduction Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation (ROHHAD) is a rare disease. To date, there have been only few reported cases of ROHHAD syndrome. Case Presentation We report a 5-year-old- Iranian girl who had normal growth and development until her 4th year of life. At that time, the patient developed weight gain, constipation, coldness in the extremities, and hyperhidros...

  1. Serotonin(4) (5-HT(4)) receptor agonists are putative antidepressants with a rapid onset of action

    DEFF Research Database (Denmark)

    Lucas, Guillaume; Rymar, Vladimir V; Du, Jenny

    2007-01-01

    parameters considered to be key markers of antidepressant action, but that are observed only after 2-3 week treatments with classical molecules: desensitization of 5-HT(1A) autoreceptors, increased tonus on hippocampal postsynaptic 5-HT(1A) receptors, and enhanced phosphorylation of the CREB protein...... intake consecutive to a chronic mild stress. These findings point out 5-HT(4) receptor agonists as a putative class of antidepressants with a rapid onset of action. Udgivelsesdato: 2007-Sep-6...

  2. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    Science.gov (United States)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2012-12-01

    We simulated the slip of a fault-patch during a large earthquake by rapidly loading an experimental, ring-shaped fault with energy stored in a spinning flywheel. The flywheel abruptly delivers a finite amount of energy by spinning the fault-patch that spontaneously dissipates the energy without operator intervention. We conducted 42 experiments on Sierra White granite (SWG) samples, and 24 experiments on Kasota dolomite (KD) samples. Each experiment starts by spinning a 225 kg disk-shaped flywheel to a prescribed angular velocity. We refer to this experiment as an "earthquake-like slip-event" (ELSE). The strength-evolution in ELSE experiments is similar to the strength-evolution proposed for earthquake models and observed in stick-slip experiments. Further, we found that ELSE experiments are similar to earthquakes in at least three ways: (1) slip driven by the release of a finite amount of stored energy; (2) pattern of fault strength evolution; and (3) seismically observed values, such as average slip, peak-velocity and rise-time. By assuming that the measured slip, D, in ELSE experiments is equivalent to the average slip during an earthquake, we found that ELSE experiments (D = 0.003-4.6 m) correspond to earthquakes in moment-magnitude range of Mw = 4-8. In ELSE experiments, the critical-slip-distance, dc, has mean values of 2.7 cm and 1.2 cm for SWG and KD, that are much shorter than the 1-10 m in steady-state classical experiments in rotary shear systems. We attribute these dc values, to ELSE loading in which the fault-patch is abruptly loaded by impact with a spinning flywheel. Under this loading, the friction-velocity relations are strikingly different from those under steady-state loading on the same rock samples with the same shear system (Reches and Lockner, Nature, 2010). We further note that the slip acceleration in ELSE evolves systematically with fault strength and wear-rate, and that the dynamic weakening is restricted to the period of intense

  3. Rapid onset of maternal vocal recognition in a colonially breeding mammal, the Australian sea lion.

    Directory of Open Access Journals (Sweden)

    Benjamin J Pitcher

    Full Text Available BACKGROUND: In many gregarious mammals, mothers and offspring have developed the abilities to recognise each other using acoustic signals. Such capacity may develop at different rates after birth/parturition, varying between species and between the participants, i.e., mothers and young. Differences in selective pressures between species, and between mothers and offspring, are likely to drive the timing of the onset of mother-young recognition. We tested the ability of Australian sea lion mothers to identify their offspring by vocalisation, and examined the onset of this behaviour in these females. We hypothesise that a rapid onset of recognition may reflect an adaptation to a colonial lifestyle. PRINCIPAL FINDINGS: In a playback study maternal responses to own pup and non-filial vocalisations were compared at 12, 24 and every subsequent 24 hours until the females' first departure post-partum. Mothers showed a clear ability to recognise their pup's voice by 48 hours of age. At 24 hours mothers called more, at 48 hours they called sooner and at 72 hours they looked sooner in response to their own pup's vocalisations compared to those of non-filial pups. CONCLUSIONS: We demonstrate that Australian sea lion females can vocally identify offspring within two days of birth and before mothers leave to forage post-partum. We suggest that this rapid onset is a result of selection pressures imposed by a colonial lifestyle and may be seen in other colonial vertebrates. This is the first demonstration of the timing of the onset of maternal vocal recognition in a pinniped species.

  4. Distinct Neuropsychological Mechanisms May Explain Delayed- Versus Rapid-Onset Antidepressant Efficacy

    Science.gov (United States)

    Stuart, Sarah A; Butler, Paul; Munafò, Marcus R; Nutt, David J; Robinson, Emma SJ

    2015-01-01

    The biochemical targets for antidepressants are relatively well established, but we lack a clear understanding of how actions at these proteins translate to clinical benefits. This study used a novel rodent assay to investigate how different antidepressant drugs act to modify affective biases that have been implicated in depression. In this bowl-digging task, rats encounter two equal value learning experiences on separate days (one during an affective manipulation and the other during control conditions). This induces an affective bias that is quantified using a preference test in which both digging substrates are presented together and the individual rats’ choices recorded. The assay can be used to measure affective biases associated with learning (when the treatment is given at the time of the experience) or examine the modification of previously acquired biases (when the treatment is administered before the preference test). The rapid-onset antidepressant ketamine, but not the delayed-onset antidepressant, venlafaxine, attenuated the previously acquired FG7142-induced negative bias following systemic administration. Venlafaxine but not ketamine induced a positive bias when administered before learning. We then used local drug infusions and excitotoxic lesions to localize the effects of ketamine to the medial prefrontal cortex and venlafaxine to the amygdala. Using a modified protocol we also showed that positive and negative biases amplified further when the numbers of substrate–reinforcer associations are increased. We propose that this pattern of results could explain the delayed onset of action of venlafaxine and the rapid onset of action but lack of long-term efficacy seen with ketamine. PMID:25740288

  5. Apospory appears to accelerate onset of meiosis and sexual embryo sac formation in sorghum ovules

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    Elliott Estella

    2011-01-01

    Full Text Available Abstract Background Genetically unreduced (2n embryo sacs (ES form in ovules of gametophytic apomicts, the 2n eggs of which develop into embryos parthenogenetically. In many apomicts, 2n ES form precociously during ovule development. Whether meiosis and sexual ES formation also occur precociously in facultative apomicts (capable of apomictic and sexual reproduction has not been studied. We determined onset timing of meiosis and sexual ES formation for 569 Sorghum bicolor genotypes, many of which produced 2n ES facultatively. Results Genotype differences for onset timing of meiosis and sexual ES formation, relative to ovule development, were highly significant. A major source of variation in timing of sexual germline development was presence or absence of apomictic ES, which formed from nucellar cells (apospory in some genotypes. Genotypes that produced these aposporous ES underwent meiosis and sexual ES formation precociously. Aposporous ES formation was most prevalent in subsp. verticilliflorum and in breeding lines of subsp. bicolor. It was uncommon in land races. Conclusions The present study adds meiosis and sexual ES formation to floral induction, apomictic ES formation, and parthenogenesis as processes observed to occur precociously in apomictic plants. The temporally diverse nature of these events suggests that an epigenetic memory of the plants' apomixis status exists throughout its life cycle, which triggers, during multiple life cycle phases, temporally distinct processes that accelerate reproduction.

  6. Preclinical evidence of rapid-onset antidepressant-like effect in Radix Polygalae extract.

    Directory of Open Access Journals (Sweden)

    Im-Joon Shin

    Full Text Available Radix Polygalae (the root of Polygala tenuifolia is a herb widely used in traditional Asian medicine that is thought to exert a variety of neuropsychiatric effects. Radix Polygalae extract can protect against N-methyl D-aspartate (NMDA neurotoxicity and induce brain-derived neurotrophic factor (BDNF expression, suggesting modulatory roles at glutamatergic synapses and possible antidepressant action. In accordance with this hypothesis, Radix Polygalae extract demonstrated antidepressant-like effects in 8-week-old male C57Bl/6 mice by decreasing behavioral despair in the forced swim and tail suspension tasks and increasing hedonic-like behavior in the female urine sniffing test 30 minutes after a single oral administration of 0.1 mg/kg. Reduced latency to acquire a food pellet in the novely suppressed feeding paradigm, without change in anxiety-like behaviors suggested a rapid-onset nature of the antidepressant-like effect. In addition, it decreased the number of failed escapes in the learned helplessness paradigm after two oral administrations 24 hours and 30 minutes before the first test. Finally, it reversed anhedonia as measured by saccharin preference in mice exposed to the chronic stress model after two administrations of 0.1 mg/kg, in contrast to the repeated administration generally needed for similar effect by monoamergic antidepressants. Immobility reduction in tail suspension task was blocked by the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA receptor antagonist NBQX, a pattern previously demonstrated by ketamine and other ketamine-like rapid-onset antidepressants. Also similarly to ketamine, Radix Polygalae appeared to acutely decrease phosphorylation of GluR1 serine-845 in the hippocampus while leaving the phosphorylation of hippocampal mTOR serine 2448 unchanged. These findings serve as preclinical evidence that Radix Polygalae extract exerts rapid-onset antidepressant effects by modulating glutamatergic synapses in

  7. Cardiac Acceleration at the Onset of Exercise : A Potential Parameter for Monitoring Progress During Physical Training in Sports and Rehabilitation

    NARCIS (Netherlands)

    Hettinga, Florentina J.; Monden, Paul G.; van Meeteren, Nico L. U.; Daanen, Hein A. M.

    There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were

  8. Cardiac acceleration at the onset of exercise: A potential parameter for monitoring progress during physical training in sports and rehabilitation

    NARCIS (Netherlands)

    Hettinga, F.J.; Monden, P.G.; Meeteren, N.L.U. van; Daanen, H.A.M.

    2014-01-01

    There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were

  9. Diet induced weight loss accelerates onset of negative alliesthesia in obese women

    Directory of Open Access Journals (Sweden)

    Frankham Patrick

    2005-10-01

    consistent with previous hedonic studies that showed delayed or absent negative alliesthesia in participants when below their initial body weight. Therefore, it is hypothesized that the accelerated onset of negative alliesthesia observed in our obese participants after weight loss is suggestive of a lowered body weight set-point. Factors inherent to the weight loss diet studied here, such as mild energetic restriction, lowered palatability, and diet composition, may have played a role in this experimental outcome.

  10. Rapidly-growing mycobacterial infection: a recognized cause of early-onset prosthetic joint infection.

    Science.gov (United States)

    Jitmuang, Anupop; Yuenyongviwat, Varah; Charoencholvanich, Keerati; Chayakulkeeree, Methee

    2017-12-28

    Prosthetic joint infection (PJI) is a major complication of total hip and total knee arthroplasty (THA, TKA). Although mycobacteria are rarely the causative pathogens, it is important to recognize and treat them differently from non-mycobacterial infections. This study aimed to compare the clinical characteristics, associated factors and long-term outcomes of mycobacterial and non-mycobacterial PJI. We conducted a retrospective case-control study of patients aged ≥18 years who were diagnosed with PJI of the hip or knee at Siriraj Hospital from January 2000 to December 2012. Patient characteristics, clinical data, treatments and outcomes were evaluated. A total of 178 patients were included, among whom 162 had non-mycobacterial PJI and 16 had mycobacterial PJI. Rapidly growing mycobacteria (RGM) (11) and M. tuberculosis (MTB) (5) were the causative pathogens of mycobacterial PJI. PJI duration and time until onset were significantly different between mycobacterial and non-mycobacterial PJI. Infection within 90 days of arthroplasty was significantly associated with RGM infection (OR 21.86; 95% CI 4.25-112.30; p infection. RGM were the major pathogens of early onset PJI after THA and TKA. Both a high clinical index of suspicion and mycobacterial cultures are recommended when medically managing PJI with negative cultures or non-response to antibiotics. Removal of infected implants was associated with favorable outcomes.

  11. Syndrome of rapid onset end stage renal disease in incident Mayo Clinic chronic hemodialysis patient

    Directory of Open Access Journals (Sweden)

    M. A. C. Onuigbo

    2014-01-01

    Full Text Available Despite decades of research, a full understanding of chronic kidney disease (CKD-end stage renal disease (ESRD progression remains elusive. The common consensus is a predictable, linear, progressive and time-dependent decline of CKD to ESRD. Acute kidney injury (AKI on CKD is usually assumed to be transient, with recovery as the expected outcome. AKI-ESRD association in current nephrology literature is blamed on the so-called "residual confounding." We had previously described a relationship between AKI events and rapid onset yet irreversible ESRD happening in a continuum in a high-risk CKD cohort. However, the contribution of the syndrome of rapid onset-ESRD (SORO-ESRD to incident United States ESRD population remained conjectural. In this retrospective analysis, we analyzed serum creatinine trajectories of the last 100 consecutive ESRD patients in 4 Mayo Clinic chronic hemodialysis units to determine the incidence of SORO-ESRD. Excluding 9 patients, 31 (34% patients, including two renal transplant recipients, had SORO-ESRD: 18 males and 13 females age 72 (range 50-92 years. Precipitating AKI followed pneumonia (8, acutely decompensated heart failure (7, pyelonephritis (4, post-operative (5, sepsis (3, contrast-induced nephropathy (2, and others (2. Time to dialysis was shortest following surgical procedures. Concurrent renin angiotensin aldosterone system blockade was higher with SORO-ESRD - 23% versus 5%, P = 0.0113. In conclusion, SORO-ESRD is not uncommon among the incident general US ESRD population. The implications for ESRD care planning, AV-fistula-first programs, general CKD care and any associations with renal ageing/senescence warrant further study.

  12. Education in a rapidly advancing technology: Accelerators and beams

    International Nuclear Information System (INIS)

    Month, Mel

    2000-01-01

    The field of accelerators and beams (A and B) is one of today's fast changing technologies. Because university faculties have not been able to keep pace with the associated advancing knowledge, universities have not been able to play their traditional role of educating the scientists and engineers needed to sustain this technology for use in science, industry, commerce, and defense. This problem for A and B is described and addressed. The solution proposed, a type of ''distance'' education, is the U.S. Particle Accelerator School (USPAS) created in the early 1980s. USPAS provides the universities with a means of serving the education needs of the institutions using A and B, primarily but not exclusively the national laboratories. The field of A and B is briefly summarized. The need for education outside the university framework, the raison d'etre for USPAS, the USPAS method, program structure, and curriculum, and particular USPAS-university connections are explained. The management of USPAS is analyzed, including its unique administrative structure, its institutional ties, and its operations, finance, marketing, and governmental relations. USPAS performance over the years is documented and a business assessment is made. Finally, there is a brief discussion of the future potential for this type of educational program, including possible extrapolation to new areas and/or different environments, in particular, its extra-government potential and its international possibilities. (c) 2000 American Association of Physics Teachers

  13. ATP1A3 Mutation in Adult Rapid-Onset Ataxia.

    Directory of Open Access Journals (Sweden)

    Kathleen J Sweadner

    Full Text Available A 21-year old male presented with ataxia and dysarthria that had appeared over a period of months. Exome sequencing identified a de novo missense variant in ATP1A3, the gene encoding the α3 subunit of Na,K-ATPase. Several lines of evidence suggest that the variant is causative. ATP1A3 mutations can cause rapid-onset dystonia-parkinsonism (RDP with a similar age and speed of onset, as well as severe diseases of infancy. The patient's ATP1A3 p.Gly316Ser mutation was validated in the laboratory by the impaired ability of the expressed protein to support the growth of cultured cells. In a crystal structure of Na,K-ATPase, the mutated amino acid was directly apposed to a different amino acid mutated in RDP. Clinical evaluation showed that the patient had many characteristics of RDP, however he had minimal fixed dystonia, a defining symptom of RDP. Successive magnetic resonance imaging (MRI revealed progressive cerebellar atrophy, explaining the ataxia. The absence of dystonia in the presence of other RDP symptoms corroborates other evidence that the cerebellum contributes importantly to dystonia pathophysiology. We discuss the possibility that a second de novo variant, in ubiquilin 4 (UBQLN4, a ubiquitin pathway component, contributed to the cerebellar neurodegenerative phenotype and differentiated the disease from other manifestations of ATP1A3 mutations. We also show that a homozygous variant in GPRIN1 (G protein-regulated inducer of neurite outgrowth 1 deletes a motif with multiple copies and is unlikely to be causative.

  14. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean.

    Science.gov (United States)

    Coxall, Helen K; Wilson, Paul A; Pälike, Heiko; Lear, Caroline H; Backman, Jan

    2005-01-06

    The ocean depth at which the rate of calcium carbonate input from surface waters equals the rate of dissolution is termed the calcite compensation depth. At present, this depth is approximately 4,500 m, with some variation between and within ocean basins. The calcite compensation depth is linked to ocean acidity, which is in turn linked to atmospheric carbon dioxide concentrations and hence global climate. Geological records of changes in the calcite compensation depth show a prominent deepening of more than 1 km near the Eocene/Oligocene boundary (approximately 34 million years ago) when significant permanent ice sheets first appeared on Antarctica, but the relationship between these two events is poorly understood. Here we present ocean sediment records of calcium carbonate content as well as carbon and oxygen isotopic compositions from the tropical Pacific Ocean that cover the Eocene/Oligocene boundary. We find that the deepening of the calcite compensation depth was more rapid than previously documented and occurred in two jumps of about 40,000 years each, synchronous with the stepwise onset of Antarctic ice-sheet growth. The glaciation was initiated, after climatic preconditioning, by an interval when the Earth's orbit of the Sun favoured cool summers. The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.

  15. The Onset and Time Course of Semantic Priming during Rapid Recognition of Visual Words

    Science.gov (United States)

    Hoedemaker, Renske S.; Gordon, Peter C.

    2016-01-01

    In two experiments, we assessed the effects of response latency and task-induced goals on the onset and time course of semantic priming during rapid processing of visual words as revealed by ocular response tasks. In Experiment 1 (Ocular Lexical Decision Task), participants performed a lexical decision task using eye-movement responses on a sequence of four words. In Experiment 2, the same words were encoded for an episodic recognition memory task that did not require a meta-linguistic judgment. For both tasks, survival analyses showed that the earliest-observable effect (Divergence Point or DP) of semantic priming on target-word reading times occurred at approximately 260 ms, and ex-Gaussian distribution fits revealed that the magnitude of the priming effect increased as a function of response time. Together, these distributional effects of semantic priming suggest that the influence of the prime increases when target processing is more effortful. This effect does not require that the task include a metalinguistic judgment; manipulation of the task goals across experiments affected the overall response speed but not the location of the DP or the overall distributional pattern of the priming effect. These results are more readily explained as the result of a retrospective rather than a prospective priming mechanism and are consistent with compound-cue models of semantic priming. PMID:28230394

  16. Safety of a rapid diagnostic protocol with accelerated stress testing.

    Science.gov (United States)

    Soremekun, Olan A; Hamedani, Azita; Shofer, Frances S; O'Conor, Katie J; Svenson, James; Hollander, Judd E

    2014-02-01

    Most patients at low to intermediate risk for an acute coronary syndrome (ACS) receive a 12- to 24-hour "rule out." Recently, trials have found that a coronary computed tomographic angiography-based strategy is more efficient. If stress testing were performed within the same time frame as coronary computed tomographic angiography, the 2 strategies would be more similar. We tested the hypothesis that stress testing can safely be performed within several hours of presentation. We performed a retrospective cohort study of patients presenting to a university hospital from January 1, 2009, to December 31, 2011, with potential ACS. Patients placed in a clinical pathway that performed stress testing after 2 negative troponin values 2 hours apart were included. We excluded patients with ST-elevation myocardial infarction or with an elevated initial troponin. The main outcome was safety of immediate stress testing defined as the absence of death or acute myocardial infarction (defined as elevated troponin within 24 hours after the test). A total of 856 patients who presented with potential ACS were enrolled in the clinical pathway and included in this study. Patients had a median age of 55.0 (interquartile range, 48-62) years. Chest pain was the chief concern in 86%, and pain was present on arrival in 73% of the patients. There were no complications observed during the stress test. There were 0 deaths (95% confidence interval, 0%-0.46%) and 4 acute myocardial infarctions within 24 hours (0.5%; 95% confidence interval, 0.14%-1.27%). The peak troponins were small (0.06, 0.07, 0.07, and 0.19 ng/mL). Patients who present to the ED with potential ACS can safely undergo a rapid diagnostic protocol with stress testing. © 2013.

  17. Anesthetic considerations for rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction (ROHHAD) syndrome in children.

    Science.gov (United States)

    Chandrakantan, Arvind; Poulton, Thomas J

    2013-01-01

    Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, and autonomic dysfunction is an increasingly common diagnosis in patients who are being seen at tertiary care children's hospitals. We present two cases of anesthetics from the authors' own experience in addition to a comprehensive review of the disorder and anesthetic implications. © 2012 Blackwell Publishing Ltd.

  18. R-ketamine: a rapid-onset and sustained antidepressant without psychotomimetic side effects

    Science.gov (United States)

    Yang, C; Shirayama, Y; Zhang, J-c; Ren, Q; Yao, W; Ma, M; Dong, C; Hashimoto, K

    2015-01-01

    Although the efficacy of racemate ketamine, a rapid onset and sustained antidepressant, for patients with treatment-resistant depression was a serendipitous finding, clinical use of ketamine is limited, due to psychotomimetic side effects and abuse liability. Behavioral and side-effect evaluation tests were applied to compare the two stereoisomers of ketamine. To elucidate their potential therapeutic mechanisms, we examined the effects of these stereoisomers on brain-derived neurotrophic factor (BDNF)–TrkB signaling, and synaptogenesis in selected brain regions. In the social defeat stress and learned helplessness models of depression, R-ketamine showed a greater potency and longer-lasting antidepressant effect than S-ketamine (esketamine). Furthermore, R-ketamine induced a more potent beneficial effect on decreased dendritic spine density, BDNF–TrkB signaling and synaptogenesis in the prefrontal cortex (PFC), CA3 and dentate gyrus (DG) of the hippocampus from depressed mice compared with S-ketamine. However, neither stereoisomer affected these alterations in the nucleus accumbens of depressed mice. In behavioral tests for side effects, S-ketamine, but not R-ketamine, precipitated behavioral abnormalities, such as hyperlocomotion, prepulse inhibition deficits and rewarding effects. In addition, a single dose of S-ketamine, but not R-ketamine, caused a loss of parvalbumin (PV)-positive cells in the prelimbic region of the medial PFC and DG. These findings suggest that, unlike S-ketamine, R-ketamine can elicit a sustained antidepressant effect, mediated by increased BDNF–TrkB signaling and synaptogenesis in the PFC, DG and CA3. R-ketamine appears to be a potent, long-lasting and safe antidepressant, relative to S-ketamine, as R-ketamine appears to be free of psychotomimetic side effects and abuse liability. PMID:26327690

  19. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): Response to ventilatory challenges.

    Science.gov (United States)

    Carroll, Michael S; Patwari, Pallavi P; Kenny, Anna S; Brogadir, Cindy D; Stewart, Tracey M; Weese-Mayer, Debra E

    2015-12-01

    Hypoventilation is a defining feature of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), a rare respiratory and autonomic disorder. This chronic hypoventilation has been explained as the result of dysfunctional chemosensory control circuits, possibly affecting peripheral afferent input, central integration, or efferent motor control. However, chemosensory function has never been quantified in a cohort of ROHHAD patients. Therefore, the purpose of this study was to assess the response to awake ventilatory challenge testing in children and adolescents with ROHHAD. The ventilatory, cardiovascular and cerebrovascular responses in 25 distinct comprehensive physiological recordings from seven unique ROHHAD patients to three different gas mixtures were analyzed at breath-to-breath and beat-to-beat resolution as absolute measures, as change from baseline, or with derived metrics. Physiologic measures were recorded during a 3-min baseline period of room air, a 3-min gas exposure (of 100% O2; 95% O2, 5% CO2; or 14% O2, 7% CO2 balanced with N2), and a 3-min recovery period. An additional hypoxic challenge was conducted which consisted of either five or seven tidal breaths of 100% N2. While ROHHAD cases showed a diminished VT and inspiratory drive response to hypoxic hypercapnia and absent behavioral awareness of the physiologic compromise, most ventilatory, cardiovascular, and cerebrovascular measures were similar to those of previously published controls using an identical protocol, suggesting a mild chemosensory deficit. Nonetheless, the high mortality rate, comorbidity and physiological fragility of patients with ROHHAD demand continued clinical vigilance. © 2015 Wiley Periodicals, Inc.

  20. Rapid Onset of Retinal Toxicity From High-Dose Hydroxychloroquine Given for Cancer Therapy.

    Science.gov (United States)

    Leung, Loh-Shan B; Neal, Joel W; Wakelee, Heather A; Sequist, Lecia V; Marmor, Michael F

    2015-10-01

    To report rapid onset of retinal toxicity in a series of patients followed on high-dose (1000 mg daily) hydroxychloroquine during an oncologic clinical trial studying hydroxychloroquine with erlotinib for non-small cell lung cancer. Retrospective observational case series. Ophthalmic surveillance was performed on patients in a multicenter clinical trial testing high-dose (1000 mg daily) hydroxychloroquine for advanced non-small cell lung cancer. The US Food & Drug Administration-recommended screening protocol included only visual acuity testing, dilated fundus examination, Amsler grid testing, and color vision testing. In patients seen at Stanford, additional sensitive screening procedures were added at the discretion of the retinal physician: high-resolution spectral-domain optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, Humphrey visual field (HVF) testing, and multifocal electroretinography (mfERG). Out of the 7 patients having exposure of at least 6 months, 2 developed retinal toxicity (at 11 and 17 months of exposure). Damage was identified by OCT imaging, mfERG testing, and, in 1 case, visual field testing. Fundus autofluorescence imaging remained normal. Neither patient had symptomatic visual acuity loss. These cases show that high doses of hydroxychloroquine can initiate the development of retinal toxicity within 1-2 years. Although synergy with erlotinib is theoretically possible, there are no prior reports of erlotinib-associated retinal toxicity despite over a decade of use in oncology. These results also suggest that sensitive retinal screening tests should be added to ongoing and future clinical trials involving high-dose hydroxychloroquine to improve safety monitoring and preservation of vision. Published by Elsevier Inc.

  1. Mutations in the Na+/K+-ATPase alpha 3 gene ATP1A3 are associated with rapid-onset dystonia parkinsonism

    NARCIS (Netherlands)

    Aguiar, PD; Sweadner, KJ; Penniston, JT; Zaremba, J; Liu, L; Caton, M; Linazasoro, G; Borg, M; Tijssen, MAJ; Bressman, SB; Dobyns, WB; Brashear, A; Ozelius, LJ

    2004-01-01

    Rapid-onset dystonia-parkinsonism (RDP, DYT12) is a distinctive autosomal-dominant movement disorder with variable expressivity and reduced penetrance characterized by abrupt onset of dystonia, usually accompanied by signs of parkinsonism. The sudden onset of symptoms over hours to a few weeks,

  2. Mutations in the Na+/K+ -ATPase alpha3 gene ATP1A3 are associated with rapid-onset dystonia parkinsonism

    NARCIS (Netherlands)

    de Carvalho Aguiar, Patricia; Sweadner, Kathleen J.; Penniston, John T.; Zaremba, Jacek; Liu, Liu; Caton, Marsha; Linazasoro, Gurutz; Borg, Michel; Tijssen, Marina A. J.; Bressman, Susan B.; Dobyns, William B.; Brashear, Allison; Ozelius, Laurie J.

    2004-01-01

    Rapid-onset dystonia-parkinsonism (RDP, DYT12) is a distinctive autosomal-dominant movement disorder with variable expressivity and reduced penetrance characterized by abrupt onset of dystonia, usually accompanied by signs of parkinsonism. The sudden onset of symptoms over hours to a few weeks,

  3. Plasmapheresis Responsive Rapid Onset Dementia with Predominantly Frontal Dysfunction in the Context of Hashimoto’s Encephalopathy

    Directory of Open Access Journals (Sweden)

    Dominique Endres

    2017-10-01

    Full Text Available BackgroundHashimoto’s encephalopathy (HE is a rare immunological neuropsychiatric disorder characterized by increased antithyroid antibodies and mixed neurological and psychiatric symptoms. HE has been previously discussed as a differential diagnosis for rapid progressive dementia. However, most of these patients suffered from additional neurological symptoms, like ataxia or seizures.Case presentationHere, we present the case of a 59-year-old female patient suffering rapid onset dementia with salient frontal executive dysfunction. She developed rapid onset symptoms, including apathy, verbal depletion up to a stuporous state, severe working memory deficits, evidence of primitive reflexes, disturbed Luria’s three-step test, and micturition disorder. Analysis of her cerebrospinal fluid was normal. The serum analyses showed increased antithyroid (antithyroid peroxidase and antithyroglobulin antibodies. In the cerebral magnetic resonance imaging, supratentorial deep and peripheral white matter lesions were found; the electroencephalography showed intermittent slowing, and the [18F]fluorodeoxyglucose positron emission tomography (FDG-PET depicted medial and superior dorsolateral frontal hypometabolism. Several different psychopharmacological therapeutic approaches with various neuroleptics, antidepressants, and high doses of lorazepam were unsuccessful. Due to the organic alterations, including increased antithyroid antibodies, HE was suspected. Against expectations, treatment with high-dose corticosteroids proved to be ineffective and was associated with worsening symptoms. However, escalated treatment with plasmapheresis over 5 days led to significant improvement in all reported symptoms and in psychometric testing. The neuropsychological improvement was stable over a 6-month follow-up period, and the FDG-PET normalized.ConclusionThis case report reveals that (1 HE can mimic rapid onset dementia with predominantly frontal dysfunction; (2 this

  4. RAPID COSMIC-RAY ACCELERATION AT PERPENDICULAR SHOCKS IN SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Takamoto, Makoto; Kirk, John G., E-mail: mtakamoto@eps.s.u-tokyo.ac.jp, E-mail: john.kirk@mpi-hd.mpg.de [Max-Planck-Institut für Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)

    2015-08-10

    Perpendicular shocks are shown to be rapid particle accelerators that perform optimally when the ratio u{sub s} of the shock speed to the particle speed roughly equals the ratio 1/η of the scattering rate to the gyro frequency. We use analytical methods and Monte-Carlo simulations to solve the kinetic equation that governs the anisotropy generated at these shocks, and find, for ηu{sub s} ≈ 1, that the spectral index softens by unity and the acceleration time increases by a factor of two compared to the standard result of the diffusive shock acceleration theory. These results provide a theoretical basis for the 30 year old conjecture that a supernova exploding into the wind of a Wolf–Rayet star may accelerate protons to an energy exceeding 10{sup 15} eV.

  5. Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD): exome sequencing of trios, monozygotic twins and tumours

    OpenAIRE

    Barclay, Sarah F.; Rand, Casey M.; Borch, Lauren A.; Nguyen, Lisa; Gray, Paul A.; Gibson, William T.; Wilson, Richard J. A.; Gordon, Paul M. K.; Aung, Zaw; Berry-Kravis, Elizabeth M.; Ize-Ludlow, Diego; Weese-Mayer, Debra E.; Bech-Hansen, N. Torben

    2015-01-01

    Background Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) is thought to be a genetic disease caused by de novo mutations, though causative mutations have yet to be identified. We searched for de novo coding mutations among a carefully-diagnosed and clinically homogeneous cohort of 35 ROHHAD patients. Methods We sequenced the exomes of seven ROHHAD trios, plus tumours from four of these patients and the unaffected monozygotic (MZ) twin ...

  6. Effect of hypovolemia, infusion, and oral rehydration on gradual onset +Gz acceleration tolerance

    Science.gov (United States)

    Greenleaf, J. E.; Brock, P. J.; Haines, R. F.; Rositano, S. A.; Montgomery, L. D.; Keil, L. C.

    1976-01-01

    The purpose of this study was to determine the effect of blood withdrawal, blood infusion, and oral fluid intake on +Gz tolerance at an acceleration rate of 0.5 G/min. Six healthy men aged 21-27 yr were centrifuged after the withdrawal of 400 ml of blood (hypovolemia) from each man; they were centrifuged again following blood infusion (Phase I). Three weeks later the men were accelerated after similar hypovolemia and again after consuming 800 ml of an isotonic NaCl drink (Phase II). Phase I hypovolemia resulted in a reduction in tolerance in all subjects from a mean control level of 6.42 + or - 0.35 min to 5.45 + or - 0.17 min (-15.1%, p less than 0.05). Both infusion and drinking returned tolerances to control levels. During acceleration there were significant (p less than 0.05) increases in plasma vasopressin levels to 35 pg/ml; these were not influenced appreciably by infusion or drinking. In all acceleration runs there was an obligatory shift (loss) of plasma volume and electrolytes, especially potassium, regardless of the experimental treatments. Oral rehydration is shown to be as effective as blood replacement in restoring +Gz acceleration tolerance decrements due to hypovolemia.

  7. ACCELERATED ONSET OF RETINAL TOXICITY FROM HYDROXYCHLOROQUINE USE WITH CONCOMITANT BREAST CANCER THERAPY.

    Science.gov (United States)

    Sharma, Aman; Maiz, Alejandra M; Tucker, William R; Cukras, Catherine

    2018-05-16

    To report a case of accelerated retinal toxicity due to hydroxychloroquine (HCQ) use for treatment of Sjögren syndrome in a patient treated with concomitant chemotherapy for breast cancer. Observational case report. A 56-year-old white woman using 400 mg HCQ (7.1 mg/kg real body weight) daily for a total of 2 years and 10 months for treatment of Sjögren syndrome with concomitant use of docetaxel and cyclophosphamide therapy (21-day cycle, 4 cycles) followed by anastrozole for breast cancer, presented with visual complaints and findings of severe HCQ toxicity. Concomitant breast cancer therapy may have a synergistic effect with HCQ leading to accelerated retinal toxicity. As such potential acceleration is poorly understood, patients on HCQ who are treated with concomitant chemotherapy should be considered for more frequent retinal screenings to maximize safety and preservation of vision.

  8. The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

    Science.gov (United States)

    Miyamoto, Tadayoshi; Oshima, Yoshitake; Ikuta, Komei; Kinoshita, Hiroshi

    2006-01-01

    Using a water immersion (WI) method, the combined effect of central blood volume (CBV) loading and work intensity on the time course of heart rate (HR) at the onset of upright dynamic exercise was investigated. Seven males cranked a cycle ergometer for 12 min using their un-immersed arms at low-, moderate- and high-work intensities, followed by a 12-min rest. For WI, the pre-exercise resting cardiac output increased by 36%, while HR decreased by 22% [from 76.8 (10.4) to 59.6 (9.8) beats/min]. WI also increased the high-frequency (HF, 0.15-0.40 Hz) component of the HR variability, suggesting an increased vagal activity. During the initial 2 min of the exercise period at low-work intensity, HR increased by 34.9 and 25.8% in the WI and control conditions, respectively. These were 117 and 73% at high-work intensity, indicating more accelerated HR with WI than the control. The plasma norepinephrine concentration increased less during high-work intensity exercise during WI, as compared to exercise during control conditions. In conclusion, the HR increase at the onset of high-work intensity exercise is accelerated by CBV loading but not at low intensity, possibly reflecting vago-sympathetic interaction and reduced baroreflex sensitivity.

  9. Rapid-onset obesity, hypoventilation, hypothalamic dysfunction, autonomic dysregulation and neuroendocrine tumor syndrome with a homogenous enlargement of the pituitary gland: a case report.

    Science.gov (United States)

    Aljabban, Lama; Kassab, Lina; Bakoura, Nour Alhuda; Alsalka, Mohammad Fayez; Maksoud, Ismaeil

    2016-11-22

    Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome is a rare pediatric disorder with a variable sequence of clinical presentations, undefined etiology, and high risk of mortality. Our patient presented an unusual course of the disease accompanied by a homogenous mild enlargement of her pituitary gland with an intact pituitary-endocrine axis which, to the best of our knowledge, represents a new finding in rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome. We present a documented case of a 4 years and 8-month-old Syrian Arabic girl with a distinctive course of signs and symptoms of rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome accompanied by mature ganglioneuroma in her chest, a homogenous mild enlargement of her pituitary gland, generalized cortical brain atrophy, and seizures. Three months after her first marked symptoms were noted she had a sudden progression of severe respiratory distress that ended with her death. The findings of this case could increase our understanding of the pathogenetic mechanisms of rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation, and place more emphases on pediatricians to consider rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome whenever early rapid onset of obesity, associated with any malfunction, is observed in children. This knowledge could be lifesaving for children with rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation syndrome.

  10. A new delirium phenotype with rapid high amplitude onset and nearly as rapid reversal: Central Coast Australia Delirium Intervention Study.

    Science.gov (United States)

    Regal, Paul J

    2015-01-01

    Traditional models for delirium based on the Diagnostic and Statistical Manual for Mental Disorders and its 1990 offspring, the Confusion Assessment Method (CAM), were not designed to distinguish behavioral and psychological symptoms of dementia from rapid cognitive decline. We examined a new diagnostic criterion for delirium plus exclusion of behavioral and psychological symptoms of dementia and recent inattention with a 25% decline in digit span forward (DSF). This was a prospective, randomized controlled trial comparing management of prevalent delirium in general medical with that in geriatric medical wards in a 370-bed hospital north of Sydney. Inclusion criteria were age ≥65 years and prevalent delirium in the emergency department based on: CAM; proof that CAM elements were not better explained by behavioral and psychological symptoms of dementia; proof of recent inattention on DSF; evidence of cognitive decline not due to sedatives or antipsychotics in the emergency department. Measurements included the Instrumental Activities of Daily Living (IADL, 22-item), Selective IADL (8-item), Mini-Mental State Examination, DSF daily, Delirium Index daily, and Apathy Evaluation Scale. Pre-delirium scores from past cognitive tests and best scores were imputed after admission. Relative change (RC) was calculated as absolute change/test range and RC/MPC ratio was calculated as RC after admission/maximal possible change. A total of 130 subjects were recruited but 14 with subsyndromal delirium were excluded, leaving 116 subjects (mean age 83.6 years). Forty-eight percent had prior dementia. RC from pre-delirium to admission was 42% for the Mini-Mental State Examination, 41% for Selective IADL, 34% for 5-DSF, 54% for 6-DSF, and 37% for the Apathy Evaluation Scale. Improvements after admission (RC and RC/MPC ratios) were 32%/98% for 5-DSF, 54%/82% for 6-DSF, and 45%/80% for the Delirium Index. General medicine and geriatric medicine groups had similar outcomes. This

  11. Dusty Cloud Acceleration by Radiation Pressure in Rapidly Star-forming Galaxies

    Science.gov (United States)

    Zhang, Dong; Davis, Shane W.; Jiang, Yan-Fei; Stone, James M.

    2018-02-01

    We perform two-dimensional and three-dimensional radiation hydrodynamic simulations to study cold clouds accelerated by radiation pressure on dust in the environment of rapidly star-forming galaxies dominated by infrared flux. We utilize the reduced speed of light approximation to solve the frequency-averaged, time-dependent radiative transfer equation. We find that radiation pressure is capable of accelerating the clouds to hundreds of kilometers per second while remaining dense and cold, consistent with observations. We compare these results to simulations where acceleration is provided by entrainment in a hot wind, where the momentum injection of the hot flow is comparable to the momentum in the radiation field. We find that the survival time of the cloud accelerated by the radiation field is significantly longer than that of a cloud entrained in a hot outflow. We show that the dynamics of the irradiated cloud depends on the initial optical depth, temperature of the cloud, and intensity of the flux. Additionally, gas pressure from the background may limit cloud acceleration if the density ratio between the cloud and background is ≲ {10}2. In general, a 10 pc-scale optically thin cloud forms a pancake structure elongated perpendicular to the direction of motion, while optically thick clouds form a filamentary structure elongated parallel to the direction of motion. The details of accelerated cloud morphology and geometry can also be affected by other factors, such as the cloud lengthscale, reduced speed of light approximation, spatial resolution, initial cloud structure, and dimensionality of the run, but these have relatively little affect on the cloud velocity or survival time.

  12. Lesion of the olfactory epithelium accelerates prion neuroinvasion and disease onset when prion replication is restricted to neurons.

    Directory of Open Access Journals (Sweden)

    Jenna Crowell

    Full Text Available Natural prion diseases of ruminants are moderately contagious and while the gastrointestinal tract is the primary site of prion agent entry, other mucosae may be entry sites in a subset of infections. In the current study we examined prion neuroinvasion and disease induction following disruption of the olfactory epithelium in the nasal mucosa since this site contains environmentally exposed olfactory sensory neurons that project directly into the central nervous system. Here we provide evidence for accelerated prion neuroinvasion and clinical onset from the olfactory mucosa after disruption and regeneration of the olfactory epithelium and when prion replication is restricted to neurons. In transgenic mice with neuron restricted replication of prions, there was a reduction in survival when the olfactory epithelium was disrupted prior to intranasal inoculation and there was >25% decrease in the prion incubation period. In a second model, the neurotropic DY strain of transmissible mink encephalopathy was not pathogenic in hamsters by the nasal route, but 50% of animals exhibited brain infection and/or disease when the olfactory epithelium was disrupted prior to intranasal inoculation. A time course analysis of prion deposition in the brain following loss of the olfactory epithelium in models of neuron-restricted prion replication suggests that neuroinvasion from the olfactory mucosa is via the olfactory nerve or brain stem associated cranial nerves. We propose that induction of neurogenesis after damage to the olfactory epithelium can lead to prion infection of immature olfactory sensory neurons and accelerate prion spread to the brain.

  13. Lesion of the Olfactory Epithelium Accelerates Prion Neuroinvasion and Disease Onset when Prion Replication Is Restricted to Neurons

    Science.gov (United States)

    Crowell, Jenna; Wiley, James A.; Bessen, Richard A.

    2015-01-01

    Natural prion diseases of ruminants are moderately contagious and while the gastrointestinal tract is the primary site of prion agent entry, other mucosae may be entry sites in a subset of infections. In the current study we examined prion neuroinvasion and disease induction following disruption of the olfactory epithelium in the nasal mucosa since this site contains environmentally exposed olfactory sensory neurons that project directly into the central nervous system. Here we provide evidence for accelerated prion neuroinvasion and clinical onset from the olfactory mucosa after disruption and regeneration of the olfactory epithelium and when prion replication is restricted to neurons. In transgenic mice with neuron restricted replication of prions, there was a reduction in survival when the olfactory epithelium was disrupted prior to intranasal inoculation and there was >25% decrease in the prion incubation period. In a second model, the neurotropic DY strain of transmissible mink encephalopathy was not pathogenic in hamsters by the nasal route, but 50% of animals exhibited brain infection and/or disease when the olfactory epithelium was disrupted prior to intranasal inoculation. A time course analysis of prion deposition in the brain following loss of the olfactory epithelium in models of neuron-restricted prion replication suggests that neuroinvasion from the olfactory mucosa is via the olfactory nerve or brain stem associated cranial nerves. We propose that induction of neurogenesis after damage to the olfactory epithelium can lead to prion infection of immature olfactory sensory neurons and accelerate prion spread to the brain. PMID:25822718

  14. COSY Control Status. First results with rapid prototyped man-machine interface for accelerator control

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, U [Forschungszentrum Juelich, Postfach 1913, 52425 Juelich (Germany); Haberbosch, C [Forschungszentrum Juelich, Postfach 1913, 52425 Juelich (Germany); Henn, K [Forschungszentrum Juelich, Postfach 1913, 52425 Juelich (Germany); Weinert, A [Forschungszentrum Juelich, Postfach 1913, 52425 Juelich (Germany)

    1994-12-15

    The experience gained with the COSY Control System after a six month commissioning period followed by a six month production period will be presented. The COSY Control System runs approximately 300 VME and VXI target systems using a total of about 1000 CPUs, the systems are driven by the diskless operating environment RT/OS, hosted by eight workcells. Application software is implemented using Object-Orientated programming paradigms. All accelerator components become interface functions as instances of an abstract device model class. Methods defined here present an abstract picture of the accelerator giving immediate access to device states and parameters. Operator interaction is defined by building views and controllers for the model. Higher level functions, such as defining an acceleration cycle, are easily developed and modified with the accelerator connected on-line to the model. In the first year of COSY operation the object based approach for a control system, together with a rapid prototyped man-machine interface has brought to light the potential of new functions such as on-line, real time programming on a running system yielding high programming performance. The advantages of this approach have not been, until now, fully appreciated. ((orig.))

  15. Rapid onset pressor response to exercise in young women with a family history of hypertension.

    Science.gov (United States)

    Matthews, Evan L; Greaney, Jody L; Wenner, Megan M

    2017-09-01

    What is the central question of this study? Alterations in blood pressure control at exercise onset are apparent in older adults with established cardiovascular disease. It is currently not known whether these alterations are evident in young adults with a family history of hypertension. What is the main finding and its importance? We demonstrate that young women with a family history of hypertension display a larger change in blood pressure within the first 10 s of isometric exercise. These data suggest altered blood pressure control in young women with a family history of hypertension. Hypertensive adults demonstrate atypical increases in blood pressure (BP) and muscle sympathetic nerve activity (MSNA) at the immediate onset of static muscle contraction. However, it is unknown whether these abnormal responses occur in young, otherwise healthy adults at risk for developing future disease, such as those with a family history of hypertension (+FH). We tested the hypothesis that +FH young women have exaggerated increases in BP and MSNA at the onset of static muscle contraction compared with those without a family history of hypertension (-FH). We retrospectively examined beat-by-beat BP and MSNA during the initial 30 s of isometric handgrip exercise (30% of maximal voluntary contraction) in 16 +FH (22 ± 2 years old, 22 ± 3 kg m -2 ) and 16 -FH (22 ± 3 years old, 22 ± 3 kg m -2 ) women. Resting mean arterial pressure (+FH 80 ± 11 mmHg versus -FH 84 ± 13 mmHg), MSNA burst frequency (+FH 7 ± 3 bursts min -1 versus -FH 9 ± 5 bursts min -1 ) and burst incidence [+FH 12 ± 4 bursts (100 heart beats) -1 versus -FH 12 ± 8 bursts (100 heart beats) -1 ] were similar between groups (all P > 0.05). Within the first 10 s of exercise, changes in mean arterial pressure (+FH Δ8 ± 6 mmHg versus -FH Δ3 ± 2 mmHg, P exercise was not different between groups (-FH 7 ± 5 bursts min -1 versus +FH 9 ± 3 bursts min -1

  16. Rapid application development by KEKB accelerator operators using EPICS/Python

    International Nuclear Information System (INIS)

    Tanaka, M.; Satoh, Y.; Kitabayashi, T.

    2004-01-01

    In the KEKB accelerator facility, the control system is constructed based on the framework of EPICS. By using EPICS/Python API, which is originated from KEK, we can develop an EPICS channel access application based on simple Python technology with only a few knowledge of EPICS channel access protocols. The operator's new tuning ideas are quickly implemented to the control system. In this paper, we introduce the EPICS/Python API and report the effectiveness of rapid application development by the KEKB operators using the API. (author)

  17. Proposed second harmonic acceleration system for the intense pulsed neutron source rapid cycling synchrotron

    International Nuclear Information System (INIS)

    Norem, J.; Brandeberry, F.; Rauchas, A.

    1983-01-01

    The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10 12 protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx.3 x 10 12 ppp, depending somewhat on the available aperture. With the present good performance in mind, accelerator improvements are being directed at: (1) increasing beam intensities for neutron science; (2) lowering acceleration losses to minimize activation; and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. On the basis of preliminary measurements, we are now proposing a third cavity for the RF systems which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses

  18. Rapid onset of squamous cell carcinoma in a thin skin graft donor site.

    Science.gov (United States)

    Herard, C; Arnaud, D; Goga, D; Rousseau, P; Potier, B

    2016-01-01

    Squamous cell carcinomas are malignant tumours of epithelial origin that can appear on sites subjected to chronic inflammation after a period of several years. The rapid development of squamous cell carcinoma at the donor site for a thin skin graft is a rare and poorly understood situation. We report the case of a patient undergoing thin skin grafting to cover the area of removal of a vertex squamous cell carcinoma and in whom squamous cell carcinoma appeared at the donor site within 9 weeks. In our case, we ruled out intraoperative contamination because two sets of surgical instruments were used. Given the number of cases reported in the literature, a chance event seems unlikely. The hypothesis of an acute inflammatory process caused by scarring of the thin skin graft site appears to us the most convincing. Development of cancer at the graft donor site may thus be added to the list of complications of thin skin grafting. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Contribution of Beta-HPV Infection and UV-Damage to Rapid-onset Cutaneous Squamous Cell Carcinoma during BRAF-inhibition Therapy

    Science.gov (United States)

    Cohen, Daniel N.; Lawson, Steven K.; Shaver, Aaron C.; Du, Liping; Nguyen, Harrison P.; He, Qin; Johnson, Douglas B.; Lumbang, Wilfred A.; Moody, Brent R.; Prescott, James L.; Chandra, Pranil K.; Boyd, Alan S.; Zwerner, Jeffrey P.; Robbins, Jason B.; Tyring, Stephen K.; Rady, Peter L.; Chappell, James D.; Shyr, Yu; Infante, Jeffrey R.; Sosman, Jeffrey A.

    2015-01-01

    Purpose BRAF-inhibition (BRAFi) therapy for advanced melanoma carries a high rate of secondary cutaneous squamous cell carcinoma (cSCC) and risk of other cancers. Ultraviolet (UV) radiation and α-genus human papillomavirus (HPV) are highly associated with SCC, but a novel role for β-genus HPV is suspected in BRAFi-cSCC. Cutaneous β-HPV may act in concert with host and environmental factors in BRAFi-cSCC. Experimental Design Primary BRAFi-cSCC tissue DNA isolated from patients receiving vemurafenib (Vem) or dabrafenib from two cancer centers was analyzed for the presence of cutaneous oncogenic viruses and host genetic mutations. Diagnostic specimens underwent consensus dermatopathology review. Clinical parameters for UV exposure and disease course were statistically analyzed in conjunction with histopathology. Results Twenty-nine patients contributed 69 BRAFi-cSCC lesions. BRAFi-cSCC had wart-like features (BRAFi-cSCC-WF) in 22% of specimens. During Vem therapy, BRAFi-cSCC-WF arose 11.6 weeks more rapidly than conventional-cSCC when controlled for gender and UV-exposure (p-value=0.03). Among all BRAFi-cSCC, β-genus HPV-17, HPV-38, HPV-111 were most frequently isolated and novel β-HPV genotypes were discovered (CTR, CRT-11, CRT-22). Sequencing revealed 63% of evaluated BRAFi-cSCCs harbored RAS mutations with PIK3CA, CKIT, ALK and EGFR mutations also detected. Conclusions We examined clinical, histopathologic, viral and genetic parameters in BRAFi-cSCC demonstrating rapid onset; wart-like histomorphology; β-HPV-17, HPV-38, and HPV-111 infection; UV damage; and novel ALK and CKIT mutations. Discovered β-HPV genotypes expand the spectrum of tumor-associated viruses. These findings enhance our understanding of factors cooperating with BRAF inhibition that accelerate keratinocyte oncogenesis as well as broaden the knowledge base of multifactorial mediators of cancer in general. PMID:25724524

  20. Nocturnal Anxiety in a Youth with Rapid-onset Obesity, Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD).

    Science.gov (United States)

    Grudnikoff, Eugene; Foley, Carmel; Poole, Claudette; Theodosiadis, Eva

    2013-08-01

    Behavioral and psychiatric disorders are common in youth with rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD). We outline a rational approach to psychiatric treatment of a patient with a complex medical condition. We report the course of symptoms in a teen with ROHHAD, the inpatient treatment, and review current evidence for use of psychopharmacologic agents in youth with sleep and anxiety disturbances. A 14-year-old female began rapidly gaining weight as a preschooler, developed hormonal imbalance, and mixed sleep apnea. Consultation was requested after a month of ROHHAD exacerbation, with severe anxiety, insomnia, and auditory hallucinations. Olanzapine and citalopram were helpful in controlling the symptoms. Following discharge, the patient gained weight and olanzapine was discontinued. Lorazepam was started in coordination with pulmonary service. Relevant pharmacologic considerations included risk of respiratory suppression, history of paradoxical reaction to hypnotics, hepatic isoenzyme interactions and side effects of antipsychotics. Core symptoms of ROHHAD may precipitate psychiatric disorders. A systematic evidence-based approach to psychopharmacology is necessary in the setting of psychiatric consultation.

  1. Human activity accelerating the rapid desertification of the Mu Us Sandy Lands, North China

    Science.gov (United States)

    Miao, Yunfa; Jin, Heling; Cui, Jianxin

    2016-01-01

    Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in the eastern Mu Us Sandy Lands. These RDEs appear to have occurred immediately following periods marked by persistently frequent and intense fires. We argue that such fire patterns, directly linked to an uncontrolled human use of vegetation as fuel, played a key role in accelerating RDEs by ensuring that the land surface was degraded beyond the threshold required for rapid desertification. This would suggest that the future use of a massive and sustained ecological program of vegetation rehabilitation should reduce the risk of destructive fire. PMID:26961705

  2. Human activity accelerating the rapid desertification of the Mu Us Sandy Lands, North China.

    Science.gov (United States)

    Miao, Yunfa; Jin, Heling; Cui, Jianxin

    2016-03-10

    Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in the eastern Mu Us Sandy Lands. These RDEs appear to have occurred immediately following periods marked by persistently frequent and intense fires. We argue that such fire patterns, directly linked to an uncontrolled human use of vegetation as fuel, played a key role in accelerating RDEs by ensuring that the land surface was degraded beyond the threshold required for rapid desertification. This would suggest that the future use of a massive and sustained ecological program of vegetation rehabilitation should reduce the risk of destructive fire.

  3. Hypoventilation improvement in an adult non-invasively ventilated patient with Rapid-onset Obesity with Hypothalamic Dysfunction Hypoventilation and Autonomic Dysregulation (ROHHAD).

    Science.gov (United States)

    Graziani, Alessandro; Casalini, Pierpaolo; Mirici-Cappa, Federica; Pezzi, Giuseppe; Giuseppe Stefanini, Francesco

    2016-01-01

    Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) is a rare disease of unknown etiology, characterized by rapid-onset obesity in young children, hypoventilation, hypothalamic and autonomic dysfunction. Patients between the ages of 2 and 4 present with hyperphagia and weight gain, followed by neuro-hormonal dysfunction and central hypoventilation months or years later. Cardiac arrest may represent the fatal complication of alveolar hypoventilation and early mechanical ventilation is essential for the patient's life. In this paper, we describe a 22-year-old patient with ROHHAD syndrome who had an acute respiratory failure during nocturnal non-invasive ventilation (NIV).

  4. Age-associated impairments in contraction-induced rapid-onset vasodilatation within the forearm are independent of mechanical factors.

    Science.gov (United States)

    Hughes, William E; Kruse, Nicholas T; Casey, Darren P

    2018-05-01

    What is the central question of this study? We examined whether the mechanical contribution to contraction-induced rapid-onset vasodilatation (ROV) differed with age and whether ROV is associated with peripheral artery stiffness. Furthermore, we examined how manipulation of perfusion pressure modulates ROV in young and older adults. What is the main finding and its importance? The mechanical contribution to ROV is similar in young and older adults. Conversely, peripheral arterial stiffness is not associated with ROV. Enhancing perfusion pressure augments ROV to a similar extent in young and older adults. These results suggest that age-related attenuations in ROV are not attributable to a mechanical component and that ROV responses are independent of peripheral artery stiffness. Contraction-induced rapid-onset vasodilatation (ROV) is modulated by perfusion and transmural pressure in young adults; however, this effect remains unknown in older adults. The present study examined the mechanical contribution to ROV in young versus older adults, the influence of perfusion pressure and whether these responses are associated with arterial stiffness. Forearm vascular conductance (in millilitres per minute per 100 mmHg) was measured in 12 healthy young (24 ± 4 years old) and 12 older (67 ± 3 years old) adults during: (i) single dynamic contractions at 20% of maximal voluntary contraction; and (ii) single external mechanical compression of the forearm (200 mmHg) positioned above, at and below heart level. Carotid-radial pulse-wave velocity characterized upper limb arterial stiffness. Total ROV responses to single muscle contractions and single external mechanical compressions were attenuated in older adults at heart level (P mechanical contribution to contraction-induced peak (46 ± 14 versus 40 ± 18%; P = 0.21) and total (37 ± 21 versus 32 ± 18%; P = 0.27) responses were not different between young and older adults. Reducing or enhancing perfusion

  5. Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD syndrome): A case report and literature review.

    Science.gov (United States)

    Ibáñez-Micó, S; Marcos Oltra, A M; de Murcia Lemauviel, S; Ruiz Pruneda, R; Martínez Ferrández, C; Domingo Jiménez, R

    ROHHAD syndrome (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) is a rare and complex disease, presenting in previously healthy children at the age of 2-4 years. Up to 40% of cases are associated with neural crest tumours. We present the case of a 2-year-old girl with symptoms of rapidly progressing obesity, who a few months later developed hypothalamic dysfunction with severe electrolyte imbalance, behaviour disorder, hypoventilation, and severe autonomic dysregulation, among other symptoms. Although the pathophysiology of this syndrome remains unclear, an autoimmune hypothesis has been proposed for ROHHAD. Therefore, after obtaining a limited response to intravenous immunoglobulins, we decided to test the response to a high dose cyclophosphamide (low dose was not effective either). Unfortunately our patient experienced many severe complications (among them central pontine myelinolysis, from which the patient recovered, and failure to wean from the ventilator requiring tracheostomy and long term ventilation) that required a prolonged ICU stay. Although her behaviour improved, our patient unfortunately died suddenly at home at the age of 5 due to respiratory pathology. ROHHAD syndrome is a rare and little-known disease which requires a multidisciplinary approach because it involves complex symptoms and multiple organ system involvement. Alveolar hypoventilation should be identified early and appropriate treatment should be started promptly for the best possible outcome. Immunomodulatory treatment with immunoglobulins, cyclophosphamide, or rituximab has previously resulted in symptom improvement in some cases. Because of the low incidence of the syndrome, multi-centre studies must be carried out in order to gather more accurate information about ROHHAD pathophysiology and design an appropriate therapeutic approach. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All

  6. Rapid emergence of subaerial landmasses and onset of a modern hydrologic cycle 2.5 billion years ago.

    Science.gov (United States)

    Bindeman, I N; Zakharov, D O; Palandri, J; Greber, N D; Dauphas, N; Retallack, G J; Hofmann, A; Lackey, J S; Bekker, A

    2018-05-01

    The history of the growth of continental crust is uncertain, and several different models that involve a gradual, decelerating, or stepwise process have been proposed 1-4 . Even more uncertain is the timing and the secular trend of the emergence of most landmasses above the sea (subaerial landmasses), with estimates ranging from about one billion to three billion years ago 5-7 . The area of emerged crust influences global climate feedbacks and the supply of nutrients to the oceans 8 , and therefore connects Earth's crustal evolution to surface environmental conditions 9-11 . Here we use the triple-oxygen-isotope composition of shales from all continents, spanning 3.7 billion years, to provide constraints on the emergence of continents over time. Our measurements show a stepwise total decrease of 0.08 per mille in the average triple-oxygen-isotope value of shales across the Archaean-Proterozoic boundary. We suggest that our data are best explained by a shift in the nature of water-rock interactions, from near-coastal in the Archaean era to predominantly continental in the Proterozoic, accompanied by a decrease in average surface temperatures. We propose that this shift may have coincided with the onset of a modern hydrological cycle owing to the rapid emergence of continental crust with near-modern average elevation and aerial extent roughly 2.5 billion years ago.

  7. Cardiac acceleration at the onset of exercise: a potential parameter for monitoring progress during physical training in sports and rehabilitation.

    Science.gov (United States)

    Hettinga, Florentina J; Monden, Paul G; van Meeteren, Nico L U; Daanen, Hein A M

    2014-05-01

    There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were searched to retrieve studies investigating HRonset. In total 652 studies were retrieved. These articles were then classified as having emphasis on HRonset in a sports or rehabilitation setting, which resulted in 8 of 112 studies with a sports application and 6 of 68 studies with a rehabilitation application that met inclusion criteria. Two co-existing mechanisms underlie HRonset: feedforward (central command) and feedback (mechanoreflex, metaboreflex, baroreflex) control. A number of studies investigated HRonset during the first few seconds of exercise (HRonsetshort), in which central command and the mechanoreflex determine vagal withdrawal, the major mechanism by which heart rate (HR) increases. In subsequent sports and rehabilitation studies, interest focused on HRonset during dynamic exercise over a longer period of time (HRonsetlong). Central command, mechanoreflexes, baroreflexes, and possibly metaboreflexes contribute to HRonset during the first seconds and minutes of exercise, which in turn leads to further vagal withdrawal and an increase in sympathetic activity. HRonset has been described as the increase in HR compared with resting state (delta HR) or by exponential modeling, with measurement intervals ranging from 0-4 s up to 2 min. Delta HR was used to evaluate HRonsetshort over the first 4 s of exercise, as well as for analyzing HRonsetlong. In exponential modeling, the HR response to dynamic exercise is biphasic, consisting of fast (parasympathetic, 0-10 s) and slow (sympathetic, 1-4 min) components. Although available studies differed largely in measurement protocols, cross-sectional and longitudinal training studies showed that studies analyzing HRonset

  8. Dual-harmonic auto voltage control for the rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    Fumihiko Tamura

    2008-07-01

    Full Text Available The dual-harmonic operation, in which the accelerating cavities are driven by the superposition of the fundamental and the second harmonic rf voltage, is useful for acceleration of the ultrahigh intensity proton beam in the rapid cycling synchrotron (RCS of Japan Proton Accelerator Research Complex (J-PARC. However, the precise and fast voltage control of the harmonics is necessary to realize the dual-harmonic acceleration. We developed the dual-harmonic auto voltage control system for the J-PARC RCS. We describe details of the design and the implementation. Various tests of the system are performed with the RCS rf system. Also, a preliminary beam test has been done. We report the test results.

  9. Rapid-Onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD): exome sequencing of trios, monozygotic twins and tumours.

    Science.gov (United States)

    Barclay, Sarah F; Rand, Casey M; Borch, Lauren A; Nguyen, Lisa; Gray, Paul A; Gibson, William T; Wilson, Richard J A; Gordon, Paul M K; Aung, Zaw; Berry-Kravis, Elizabeth M; Ize-Ludlow, Diego; Weese-Mayer, Debra E; Bech-Hansen, N Torben

    2015-08-25

    Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD) is thought to be a genetic disease caused by de novo mutations, though causative mutations have yet to be identified. We searched for de novo coding mutations among a carefully-diagnosed and clinically homogeneous cohort of 35 ROHHAD patients. We sequenced the exomes of seven ROHHAD trios, plus tumours from four of these patients and the unaffected monozygotic (MZ) twin of one (discovery cohort), to identify constitutional and somatic de novo sequence variants. We further analyzed this exome data to search for candidate genes under autosomal dominant and recessive models, and to identify structural variations. Candidate genes were tested by exome or Sanger sequencing in a replication cohort of 28 ROHHAD singletons. The analysis of the trio-based exomes found 13 de novo variants. However, no two patients had de novo variants in the same gene, and additional patient exomes and mutation analysis in the replication cohort did not provide strong genetic evidence to implicate any of these sequence variants in ROHHAD. Somatic comparisons revealed no coding differences between any blood and tumour samples, or between the two discordant MZ twins. Neither autosomal dominant nor recessive analysis yielded candidate genes for ROHHAD, and we did not identify any potentially causative structural variations. Clinical exome sequencing is highly unlikely to be a useful diagnostic test in patients with true ROHHAD. As ROHHAD has a high risk for fatality if not properly managed, it remains imperative to expand the search for non-exomic genetic risk factors, as well as to investigate other possible mechanisms of disease. In so doing, we will be able to confirm objectively the ROHHAD diagnosis and to contribute to our understanding of obesity, respiratory control, hypothalamic function, and autonomic regulation.

  10. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  11. An accelerating reference frame for electromagnetic waves in a rapidly growing plasma

    International Nuclear Information System (INIS)

    Yablonovitch, E.

    1989-01-01

    In 1974, Hawking showed that black holes can evaporate by the emission of low temperature thermal radiation, now named Hawking radiation. Shortly thereafter, a closely related effect called Unruh radiation became apparent. The author discusses how, according to Unruh and Davies, observers of the electromagnetic field in an accelerating reference frame should see thermal radiation at a temperature T: KT = h/2π a/c where a is the acceleration relative to an inertial frame, c is the speed of light and h and K are Planck's and Boltzmann's constant respectively. In a frame accelerating at g = 980 cm/sec 2 , equivalent to the acceleration experienced at the earth's surface, this thermal radiation is at a temperature of only 4 x 10 -20 degrees K. Therefore, physicists hoping to observe this radiation, have sought out systems being subjected to extreme acceleration

  12. Repeated delayed onset cerebellar radiation injuries after linear accelerator-based stereotactic radiosurgery for vestibular schwannoma. Case report

    International Nuclear Information System (INIS)

    Ujifuku, Kenta; Matsuo, Takayuki; Toyoda, Keisuke

    2012-01-01

    A 63-year-old woman presented with right hearing disturbance and vertigo. Magnetic resonance (MR) imaging revealed the presence of right vestibular schwannoma (VS). Stereotactic radiosurgery (SRS) was performed with a tumor marginal dose of 14 Gy using two isocenters. She was followed up clinically and neuroradiologically using three-dimensional spoiled gradient-echo MR imaging. She experienced temporal neurological deterioration due to peritumoral edema in her right cerebellar peduncle and pons for a few months beginning 1.5 years after SRS, when she experienced transient right facial dysesthesia and hearing deterioration. Ten years after SRS, the patient presented with sudden onset of vertigo, gait disturbance, diplopia, dysarthria, and nausea. MR imaging demonstrated a new lesion in the right cerebellar peduncle, which was diagnosed as radiation-induced stroke. The patient was followed up conservatively and her symptoms disappeared within a few months. Multiple delayed onset radiation injuries are possible sequelae of SRS for VS. (author)

  13. INJECTION TO RAPID DIFFUSIVE SHOCK ACCELERATION AT PERPENDICULAR SHOCKS IN PARTIALLY IONIZED PLASMAS

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Yutaka, E-mail: ohira@phys.aoyama.ac.jp [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara 252-5258 (Japan)

    2016-08-10

    We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and upstream ionization fraction are v {sub sh} ≈ 1333 km s{sup −1} and f {sub i} ∼ 0.5, which are typical values for isolated young supernova remnants (SNRs) in the interstellar medium. We confirm previous two-dimensional simulation results showing that downstream hydrogen atoms leak into the upstream region and are accelerated by the pickup process in the upstream region, and large magnetic field fluctuations are generated both in the upstream and downstream regions. In addition, we find that the magnetic field fluctuations have three-dimensional structures and the leaking hydrogen atoms are injected into the diffusive shock acceleration (DSA) at the perpendicular shock after the pickup process. The observed DSA can be interpreted as shock drift acceleration with scattering. In this simulation, particles are accelerated to v ∼ 100 v {sub sh} ∼ 0.3 c within ∼100 gyroperiods. The acceleration timescale is faster than that of DSA in parallel shocks. Our simulation results suggest that SNRs can accelerate cosmic rays to 10{sup 15.5} eV (the knee) during the Sedov phase.

  14. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Science.gov (United States)

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  15. First report of two rapid-onset fatal infections caused by a newly emerging hypervirulent K. Pneumonia ST86 strain of serotype K2 in China.

    Science.gov (United States)

    Zhang, Yibo; Sun, Jingyong; Mi, Chenrong; Li, Wenhui; Zhao, Shengyuan; Wang, Qun; Shi, Dake; Liu, Luo; Ding, Bingyu; Chang, Yung-Fu; Guo, Hongxiong; Guo, XiaoKui; Li, Qingtian; Zhu, Yongzhang

    2015-01-01

    Here, we present the first report of one suspected dead case and two confirmed rapid-onset fatal infections caused by a newly emerging hypervirulent Klebsiella pneumoniae ST86 strain of serotype K2. The three cases occurred in a surgery ward during 2013 in Shanghai, China. A combination of multilocus sequence typing, pulsed-field gel electrophoresis, phenotypic and PCR tests for detecting virulence factors (VFs) was used to identify the isolates as K2 ST86 strains with common VFs, including Aerobactin and rmpA. Furthermore, the two K2 ST86 strains additionally harbored a distinct VF kfu (responsible for iron uptake system), which commonly existed in invasive K1 strains only. Thus, the unusual presence of both K1 and K2 VFs in the lethal ST86 strain might further enhance its hypervirulence and cause rapid onset of a life-threatening infection. Nevertheless, despite the administration of a combined antibiotic treatment, these three patients all died within 24 h of acute onset, thereby highlighting that the importance of early diagnosis to determine whether the ST86 strains harbor key K2 VF and unusual K1 kfu and whether patients should receive a timely and targeted antibiotic therapy to prevent ST86 induced fatal pneumonia. Finally, even though these patients are clinically improved, keeping on with oral antibiotic treatment for additional 2-3 weeks will be also vital for successfully preventing hvKP reinfection or relapse.

  16. Beam commissioning of the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    H. Hotchi

    2009-04-01

    Full Text Available The 3-GeV rapid cycling synchrotron (RCS of the Japan Proton Accelerator Research Complex (J-PARC was commissioned in October 2007, and successfully accomplished 3 GeV acceleration on October 31. Six run cycles through February 2008 were dedicated to commissioning the RCS, for which the initial machine parameter tuning and various underlying beam studies were completed. Then since May 2008 the RCS beam has been delivered to the downstream facilities for their beam commissioning. In this paper we describe beam tuning and study results following our beam commissioning scenario and a beam performance and operational experience obtained in the first commissioning phase through June 2008.

  17. Rapid recovery from congestive heart failure following successful radiofrequency catheter ablation in a patient with late onset of Wolff-Parkinson-White syndrome.

    Science.gov (United States)

    Yodogawa, Kenji; Ono, Norihiko; Seino, Yoshihiko

    2012-01-01

    A 56-year-old man was admitted because of palpitations and dyspnea. A 12-lead electrocardiogram showed irregular wide QRS complex tachycardia with a slur at the initial portion of the QRS complex. He had preexisting long-standing persistent atrial fibrillation, but early excitation syndrome had never been noted. Chest X-ray showed heart enlargement and pulmonary congestion. He was diagnosed with late onset of Wolff-Parkinson-White syndrome, and congestive heart failure was probably caused by rapid ventricular response of atrial fibrillation through the accessory pathway. Emergency catheter ablation for the accessory pathway was undertaken, and heart failure was dramatically improved.

  18. Rapid ascent: Rocky Mountain National Park in the Great Acceleration, 1945-present

    Science.gov (United States)

    Boxell, Mark

    After the Second World War's conclusion, Rocky Mountain National Park (RMNP) experienced a massive rise in visitation. Mobilized by an affluent economy and a growing, auto-centric infrastructure, Americans rushed to RMNP in droves, setting off new concerns over the need for infrastructure improvements in the park. National parks across the country experienced similar explosions in visitation, inspiring utilities- and road-building campaigns throughout the park units administered by the National Park Service. The quasi-urbanization of parks like RMNP implicated the United States' public lands in a process of global change, whereby wartime technologies, cheap fossil fuels, and a culture of techno-optimism--epitomized by the Mission 66 development program--helped foster a "Great Acceleration" of human alterations of Earth's natural systems. This transformation culminated in worldwide turns toward mass-urbanization, industrial agriculture, and globalized markets. The Great Acceleration, part of the Anthropocene--a new geologic epoch we have likely entered, which proposes that humans have become a force of geologic change--is used as a conceptual tool for understanding the connections between local and global changes which shaped the park after World War II. The Great Acceleration and its array of novel technologies and hydrocarbon-powered infrastructures produced specific cultures of tourism and management techniques within RMNP. After World War II, the park increasingly became the product and distillation of a fossil fuel-dependent society.

  19. Co-administration of dexamethasone increases severity and accelerates onset day of neutropenia in bladder cancer patients on methotrexate, vinblastine, adriamycin and cisplatin chemotherapy: a retrospective cohort study.

    Science.gov (United States)

    Itai, Shingo; Suga, Yukio; Hara, Yusuke; Izumi, Kouji; Maeda, Yuji; Kitagawa, Yasuhide; Ishizaki, Junko; Shimada, Tsutomu; Mizokami, Atsushi; Sai, Yoshimichi

    2017-01-01

    Bladder cancer patients receiving methotrexate, vinblastine, adriamycin and cisplatin (MVAC) chemotherapy are co-administered with dexamethasone as an anti-emetic. We examined whether or not dexamethasone affects the severity and onset day of MVAC-induced severe neutropenia. This was a retrospective study of bladder cancer patients treated with MVAC chemotherapy with or without dexamethasone as an antiemetic at Kanazawa University Hospital during January 2005 - December 2009. Patients were categorized into three groups; no dexamethasone use (Dex (-)), dexamethasone on day 2 (Dex 1 day), and dexamethasone on days 2, 3 and 4 (Dex multiday). We evaluated the incidence of grade 3/4 neutropenia and the day of onset of first severe neutropenic episode during the first course of MVAC chemotherapy. Logistic regression was used to investigate whether co-administration of dexamethasone was a risk factor for severe neutropenia. Episodes of grade 3/4 neutropenia occurred in 3 out of 6 (50.0%), 11 out of 12 (91.7%) and 6 out of 6 (100%) patients in the Dex (-), Dex 1 day, and Dex multiday groups, respectively. The appearance day of first severe neutropenia in the Dex multiday group (13.2 ± 1.0) was significantly accelerated compared to the Dex (-) group (17.7 ± 2.1). Univariate logistic regression analysis revealed that dexamethasone is a risk factor for severe neutropenia (OR 17.0; 95%CI: 1.3-223.1). Co-administration of dexamethasone for anti-emesis brings forward the first appearance of neutropenia, and increases the severity of neutropenia, in bladder cancer patients receiving MVAC chemotherapy.

  20. The financial impact of the incorporation of IMRT and RapidArc™ techniques on shielding calculation of a linear accelerator

    International Nuclear Information System (INIS)

    Santos, Maira R.; Silveira, Thiago B.; Garcia, Paulo L.; Trindade, Cassia; Martins, Lais P.; Batista, Delano V.S.

    2013-01-01

    Given the new methodology introduced in the shielding calculation due to recent modulated techniques in radiotherapy treatment, it became necessary to evaluate the impact of changes in the accelerator routine using such techniques. Based on a group of 30 patients from the National Cancer Institute (INCA) the workload multiplier factors for intensity modulated radiotherapy (IMRT factor) and for RapidArc™ (RA factor) were established. Four different routines in a 6 MV generic accelerator were proposed to estimate the impact of these modified workloads in the building cost of the secondary barriers. The results indicate that if 50% of patients are treating with IMRT, the secondary barrier becomes 14,1% more expensive than the barrier calculated for conformal treatments exclusive. While RA, in the same proportion, leads to a barrier only 3,7% more expensive. Showing that RA can, while reducing treatment time, increase the proportion of patients treated with modulation technique, without increasing the cost of the barrier, when compared with IMRT. (author)

  1. Rapid Analyses of Polyetheretherketone Wear Characteristics by Accelerated Wear Testing with Microfabricated Surfaces for Artificial Joint Systems.

    Science.gov (United States)

    Su, Chen-Ying; Kuo, Chien-Wei; Fang, Hsu-Wei

    2017-01-01

    Wear particle-induced biological responses are the major factors resulting in the loosening and then failure of total joint arthroplasties. It is feasible to improve the lubrication and reduce the wear of artificial joint system. Polyetheretherketone (PEEK) is considered as a potential bearing material due to its mechanical characteristics of resistance to fatigue strain. The PEEK wear particles have been indicated to be involved in biological responses in vitro, and further studies regarding the wear phenomena and wear particle generation are needed. In this study, we have established an accelerated wear testing system with microfabricated surfaces. Various contact pressures and lubricants have been utilized in the accelerated wear tests. Our results showed that increasing contact pressure resulted in an increase of wear particle sizes and wear rate, and the size of PEEK wear particles can be controlled by the feature size of microfabricated surfaces. These results provided the information rapidly about factors that affect the morphology and amount of PEEK wear particles and can be applied in the future for application of PEEK on the biological articulation system.

  2. The effects of nicardipine or esmolol on the onset time of rocuronium and intubation conditions during rapid sequence induction: a randomized double-blind trial.

    Science.gov (United States)

    Lee, Ji Heui; Kim, Yunkwang; Lee, Kye Hyeok; Rim, Sung Kyu; Lee, Ji Yeon; Lee, Cheong

    2015-06-01

    The main aims of rapid sequence induction (RSI) are prompt and adequate muscle relaxation for tracheal intubation and hemodynamic stability during and after intubation. The purpose of the present study was to investigate the effects of nicardipine and esmolol on the action of rocuronium and intubation conditions during RSI. Adult patients (n = 82) were randomly allocated to one of three groups. One minute prior to the induction of sevoflurane-based general anesthesia, patients received 20 μg/kg of nicardipine (N group; n = 27) or 0.5 mg/kg of esmolol (E group; n = 27), or 5 ml of saline (C group; n = 28). Patients were assessed according to intubation conditions, the onset time of rocuronium, mean arterial pressure (MAP), and heart rate (HR) during RSI. The intubation conditions and score were significantly better in the C and N groups than in the E group (P rocuronium was shortened in the N group and prolonged in the E group when compared to the C group (P rocuronium and attenuated changes in MAP after intubation. Esmolol may disturb intubation conditions and the onset of action of rocuronium, despite being effective in alleviating responses of HR after RSI.

  3. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome may have a hypothalamus-periaqueductal gray localization.

    Science.gov (United States)

    Chow, Cristelle; Fortier, Marielle Valerie; Das, Lena; Menon, Anuradha P; Vasanwala, Rashida; Lam, Joyce C M; Ng, Zhi Min; Ling, Simon Robert; Chan, Derrick W S; Choong, Chew Thye; Liew, Wendy K M; Thomas, Terrence

    2015-05-01

    Anatomical localization of the rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) syndrome has proved elusive. Most patients had neuroimaging after cardiorespiratory collapse, revealing a range of ischemic lesions. A 15-year-old obese boy with an acute febrile encephalopathy had hypoventilation, autonomic dysfunction, visual hallucinations, hyperekplexia, and disordered body temperature, and saltwater regulation. These features describe the ROHHAD syndrome. Cerebrospinal fluid analysis showed pleocytosis, elevated neopterins, and oligoclonal bands, and serology for systemic and antineuronal antibodies was negative. He improved after receiving intravenous steroids, immunoglobulins, and long-term mycophenolate. Screening for neural crest tumors was negative. Magnetic resonance imaging of the brain early in his illness showed focal inflammation in the periaqueductal gray matter and hypothalamus. This unique localization explains almost all symptoms of this rare autoimmune encephalitis. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Mutations Phe785Leu and Thr618Met in Na+, K+-ATPase, Associated with Familial Rapid-Onset Dystonia Parkinsonism, Interfere with Na+ Interaction by Distinct Mechanisms

    DEFF Research Database (Denmark)

    Schack, Vivien Rodacker; Toustrup-Jensen, Mads Schak; Vilsen, Bente

    The Na+, K+-ATPase plays key roles in brain function. Recently, missense mutations in the Na+, K+-ATPase were found associated with familial rapid-onset dystonia parkinsonism (FRDP). Here, we have characterized the functional consequences of FRDP mutations Phe785Leu and Thr618Met. Both mutations...... lead to functionally altered, but active, Na+, K+-pumps that display reduced apparent affinity for cytoplasmic Na+, but the underlying mechanism differs between the mutants. In Phe785Leu, the interaction of the E1 form with Na+ is defective, and the E1-E2 equilibrium is not displaced. In Thr618Met......, the Na+ affinity is reduced because of displacement of the conformational equilibrium in favor of the K+-occluded E2(K2) form. In both mutants, K+ interaction at the external activating sites of the E2P phosphoenzyme is normal. The change of cellular Na+ homeostasis is likely a major factor contributing...

  5. Mutations Phe785Leu and Thr618Met in Na+, K+-ATPase, Associated with Familial Rapid-Onset Dystonia Parkinsonism, Interfere with Na+ Interaction by Distinct Mechanisms

    DEFF Research Database (Denmark)

    Schack, Vivien Rodacker; Toustrup-Jensen, Mads Schak; Vilsen, Bente

    The Na+, K+-ATPase plays key roles in brain function. Recently, missense mutations in the Na+, K+-ATPase were found associated with familial rapid-onset dystonia parkinsonism (FRDP). We have characterized the functional consequences of FRDP mutations Phe785Leu and Thr618Met. Both mutations lead...... to functionally altered, but active, Na+, K+-pumps that display reduced apparent affinity for cytoplasmic Na+, but the underlying mechanism differs between the mutants. In Phe785Leu, the interaction of the E1 form with Na+ is defective, and the E1-E2 equilibrium is not displaced. In Thr618Met, the Na+ affinity...... is reduced because of displacement of the conformational equilibrium in favor of the K+-occluded E2(K2) form. In both mutants, K+ interaction at the external activating sites of the E2P phosphoenzyme is normal. The change of cellular Na+ homeostasis is likely a major factor contributing to the development...

  6. Rapid onset of treatment effects on psychosis, depression, and mania in patients with acute exacerbation of schizoaffective disorder following treatment with oral extended-release paliperidone.

    Science.gov (United States)

    Fu, Dong-Jing; Turkoz, Ibrahim; Bossie, Cynthia A; Patel, Hiren; Alphs, Larry

    2016-03-15

    Patients with schizoaffective disorder (SCA) experience complicated interplays of psychotic, depressive, and manic symptoms. Paliperidone extended-release (pali ER) tablets have been shown to be efficacious in these patients, but treatment response has not been studied relative to the onset of effects for these symptom domains. In a pooled analysis of data from two 6-week, randomized, placebo-controlled studies, the onset of treatment effects with oral pali ER was evaluated by symptom domain (psychosis, depression, mania) in patients with an acute SCA exacerbation. Subjects were categorized as having prominent psychotic (Positive and Negative Syndrome Scale score >70), depressive (Hamilton Rating Scale for Depression-21 score ≥16), or manic (Young Mania Rating Scale score ≥16) symptoms at baseline. Of the 614 patients in these analyses, 597 (97.2%), 411 (66.9%), and 488 (79.5%) had prominent psychotic, depressive, and manic symptoms at baseline, respectively. Pali ER treatment was associated with rapid and significant improvement of all three symptom domains versus placebo within 1 week of initiation, regardless of whether treatment was given as monotherapy or in combination with mood stabilizers and/or antidepressants. Adverse events were similar to those reported in the original published studies. This post hoc analysis of two phase 3 trials requires confirmation in prospective studies. This pooled analysis suggests that treatment with pali ER is associated with rapid control of psychotic, depressive, and manic symptoms in patients with SCA. Its findings support the benefit of pali ER as a primary treatment for the management of SCA. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Modelling multi-phase liquid-sediment scour and resuspension induced by rapid flows using Smoothed Particle Hydrodynamics (SPH) accelerated with a Graphics Processing Unit (GPU)

    Science.gov (United States)

    Fourtakas, G.; Rogers, B. D.

    2016-06-01

    A two-phase numerical model using Smoothed Particle Hydrodynamics (SPH) is applied to two-phase liquid-sediments flows. The absence of a mesh in SPH is ideal for interfacial and highly non-linear flows with changing fragmentation of the interface, mixing and resuspension. The rheology of sediment induced under rapid flows undergoes several states which are only partially described by previous research in SPH. This paper attempts to bridge the gap between the geotechnics, non-Newtonian and Newtonian flows by proposing a model that combines the yielding, shear and suspension layer which are needed to predict accurately the global erosion phenomena, from a hydrodynamics prospective. The numerical SPH scheme is based on the explicit treatment of both phases using Newtonian and the non-Newtonian Bingham-type Herschel-Bulkley-Papanastasiou constitutive model. This is supplemented by the Drucker-Prager yield criterion to predict the onset of yielding of the sediment surface and a concentration suspension model. The multi-phase model has been compared with experimental and 2-D reference numerical models for scour following a dry-bed dam break yielding satisfactory results and improvements over well-known SPH multi-phase models. With 3-D simulations requiring a large number of particles, the code is accelerated with a graphics processing unit (GPU) in the open-source DualSPHysics code. The implementation and optimisation of the code achieved a speed up of x58 over an optimised single thread serial code. A 3-D dam break over a non-cohesive erodible bed simulation with over 4 million particles yields close agreement with experimental scour and water surface profiles.

  8. The expanding spectrum of neurological phenotypes in children with ATP1A3 mutations, Alternating Hemiplegia of Childhood, Rapid-onset Dystonia-Parkinsonism, CAPOS and beyond.

    Science.gov (United States)

    Sweney, Matthew T; Newcomb, Tara M; Swoboda, Kathryn J

    2015-01-01

    ATP1A3 mutations have now been recognized in infants and children presenting with a diverse group of neurological phenotypes, including Rapid-onset Dystonia-Parkinsonism (RDP), Alternating Hemiplegia of Childhood (AHC), and most recently, Cerebellar ataxia, Areflexia, Pes cavus, Optic atrophy, and Sensorineural hearing loss (CAPOS) syndrome. Existing literature on ATP1A3-related disorders in the pediatric population were reviewed, with attention to clinical features and associated genotypes among those with RDP, AHC, or CAPOS syndrome phenotypes. While classically defined phenotypes associated with AHC, RDP, and CAPOS syndromes are distinct, common elements among ATP1A3-related neurological disorders include characteristic episodic neurological symptoms and signs that vary in severity, duration, and frequency of occurrence. Affected children typically present in the context of an acute onset of paroxysmal, episodic neurological symptoms ranging from oculomotor abnormalities, hypotonia, paralysis, dystonia, ataxia, seizure-like episodes, or encephalopathy. Neurodevelopmental delays or persistence of dystonia, chorea, or ataxia after resolution of an initial episode are common, providing important clues for diagnosis. The phenotypic spectrum of ATP1A3-related neurological disorders continues to expand beyond the distinct yet overlapping phenotypes in patients with AHC, RDP, and CAPOS syndromes. ATP1A3 mutation analysis is appropriate to consider in the diagnostic algorithm for any child presenting with episodic or fluctuating ataxia, weakness or dystonia whether they manifest persistence of neurological symptoms between episodes. Additional work is needed to better identify and classify affected patients and develop targeted treatment approaches. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W W; Ruskov, E; Fredrickson, E D; Gorelenkov, N; Medley, S S; Berk, H L; Harvey, R W

    2006-01-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ∼2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (∼<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed

  10. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W W [University of California, Irvine, California (United States); Ruskov, E [University of California, Irvine, California (United States); Fredrickson, E D [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Gorelenkov, N [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Medley, S S [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Berk, H L [University of Texas, Austin, Texas (United States); Harvey, R W [CompX, Del Mar, California (United States)

    2006-09-15

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at {approx}2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power ({approx}<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  11. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    W W,Heidbrink; E,Ruskov; E D,Fredrickson; N,Gorelenkov; S S,Medley; H L,Berk; R W,Harvey

    2006-09-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ~2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50–100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10–20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (≤3MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  12. Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

    Science.gov (United States)

    Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

    2014-11-19

    Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence

  13. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD): a case with additional features and review of the literature.

    Science.gov (United States)

    Chew, H B; Ngu, L H; Keng, W T

    2011-03-01

    A rare syndrome of rapid-onset obesity with hypothalamic dysfunction, hypoventilation and autonomic dysregulation (ROHHAD) has been recently described. We report the first patient with this syndrome in Southeast Asia and review reported cases to date. Our patient was good health with normal development until the age of 2. He then developed hyperphagic obesity, hypersomnolence, seizures, alveolar hypoventilation, central hypothyroidism, sodium and water dysregulation, gastrointestinal dysmotility, strabismus, disordered temperature and irregular heart rate, altered sweating, delayed puberty, mental retardation and recurrent respiratory tract infections. The cardiomyopathy with heart failure and abnormal cerebral spinal fluid (CSF) neurotransmitter analysis present in our patient have not been reported previously. Tumours of the sympathetic nervous system are known to be associated with this syndrome but had not been found in our patient at the time of reporting. We highlight the difficulty of achieving the diagnosis of ROHHAD syndrome and its overlap with other well-established disease entities. The mortality and morbidity resulting from the high incidence of cardiorespiratory arrest may be prevented by early ventilatory support.

  14. Elevated Basal Pre-infection CXCL10 in Plasma and in the Small Intestine after Infection Are Associated with More Rapid HIV/SIV Disease Onset.

    Directory of Open Access Journals (Sweden)

    Mickaël J Ploquin

    2016-08-01

    Full Text Available Elevated blood CXCL10/IP-10 levels during primary HIV-1 infection (PHI were described as an independent marker of rapid disease onset, more robust than peak viremia or CD4 cell nadir. IP-10 enhances the recruitment of CXCR3+ cells, which include major HIV-target cells, raising the question if it promotes the establishment of viral reservoirs. We analyzed data from four cohorts of HIV+ patients, allowing us to study IP-10 levels before infection (Amsterdam cohort, as well as during controlled and uncontrolled viremia (ANRS cohorts. We also addressed IP-10 expression levels with regards to lymphoid tissues (LT and blood viral reservoirs in patients and non-human primates. Pre-existing elevated IP-10 levels but not sCD63 associated with rapid CD4 T-cell loss upon HIV-1 infection. During PHI, IP-10 levels and to a lesser level IL-18 correlated with cell-associated HIV DNA, while 26 other inflammatory soluble markers did not. IP-10 levels tended to differ between HIV controllers with detectable and undetectable viremia. IP-10 was increased in SIV-exposed aviremic macaques with detectable SIV DNA in tissues. IP-10 mRNA was produced at higher levels in the small intestine than in colon or rectum. Jejunal IP-10+ cells corresponded to numerous small and round CD68neg cells as well as to macrophages. Blood IP-10 response negatively correlated with RORC (Th17 marker gene expression in the small intestine. CXCR3 expression was higher on memory CD4+ T cells than any other immune cells. CD4 T cells from chronically infected animals expressed extremely high levels of intra-cellular CXCR3 suggesting internalization after ligand recognition. Elevated systemic IP-10 levels before infection associated with rapid disease progression. Systemic IP-10 during PHI correlated with HIV DNA. IP-10 production was regionalized in the intestine during early SIV infection and CD68+ and CD68neg haematopoietic cells in the small intestine appeared to be the major source of IP-10.

  15. The rapid-onset dystonia parkinsonism mutation D923N of the Na+, K+-ATPase alpha3 isoform disrupts Na+ interaction at the third Na+ site.

    Science.gov (United States)

    Einholm, Anja Pernille; Toustrup-Jensen, Mads S; Holm, Rikke; Andersen, Jens Peter; Vilsen, Bente

    2010-08-20

    Rapid-onset dystonia parkinsonism (RDP), a rare neurological disorder, is caused by mutation of the neuron-specific alpha3-isoform of Na(+), K(+)-ATPase. Here, we present the functional consequences of RDP mutation D923N. Relative to the wild type, the mutant exhibits a remarkable approximately 200-fold reduction of Na(+) affinity for activation of phosphorylation from ATP, reflecting a defective interaction of the E(1) form with intracellular Na(+). This is the largest effect on Na(+) affinity reported so far for any Na(+), K(+)-ATPase mutant. D923N also affects the interaction with extracellular Na(+) normally driving the E(1)P to E(2)P conformational transition backward. However, no impairment of K(+) binding was observed for D923N, leading to the conclusion that Asp(923) is specifically associated with the third Na(+) site that is selective toward Na(+). The crystal structure of the Na(+), K(+)-ATPase in E(2) form shows that Asp(923) is located in the cytoplasmic half of transmembrane helix M8 inside a putative transport channel, which is lined by residues from the transmembrane helices M5, M7, M8, and M10 and capped by the C terminus, recently found involved in recognition of the third Na(+) ion. Structural modeling of the E(1) form of Na(+), K(+)-ATPase based on the Ca(2+)-ATPase crystal structure is consistent with the hypothesis that Asp(923) contributes to a site binding the third Na(+) ion. These results in conjunction with our previous findings with other RDP mutants suggest that a selective defect in the handling of Na(+) may be a general feature of the RDP disorder.

  16. Evaluation of the Implementation of a Rapid Response Treatment Protocol for Patients with Acute Onset Stroke: Can We Increase the Number of Patients Treated and Shorten the Time Needed

    Directory of Open Access Journals (Sweden)

    Rajiv Advani

    2014-06-01

    Full Text Available Aims: This study aims to evaluate the implementation of a rapid response treatment protocol for patients presenting with acute onset ischemic stroke. Improvements of routines surrounding the admission and treatment of patients with intravenous thrombolysis (IVT, such as door-to-needle (DTN times, and increasing the numbers of patients treated are discussed. Methods: We conducted a retrospective analysis of all patients (n = 320 treated with IVT for acute onset ischemic stroke at the Stavanger University Hospital, Norway, between 2003 and 2012. In 2009, a succession of changes to pre- and intra-hospital routines were made as well as an improvement in the education of primary health care physicians, nurses and paramedics involved in the treatment of acute onset stroke patients (rapid response treatment protocol. Analyses of DTN times, onset-to-needle times and the number of patients treated per year were carried out to ascertain the effect of the changes made. The primary aim was to analyze DTN times to look for any changes, and the secondary aim was to analyze changes in the number of patients treated per year. Results: In the years after the implementation of the rapid treatment protocol, we saw an improvement in the median DTN time with a decrease from 73 to 50 min in the first year (p = 0.03, a decrease of 45 min in the second year (p = 0.01 and a decrease of 31 min in the third year (p Conclusions: The implementation of the rapid treatment protocol for acute onset ischemic stroke patients led to a significant decrease in the DTN time at our center. These improvements also produced an increase in the number of patients treated per year. The extension of the therapeutic window from 3 to 4.5 h for the use of intravenous recombinant tissue plasminogen activator also played a role in the increased treatment numbers.

  17. Do rapid BMI growth in childhood and early-onset obesity offer cardiometabolic protection to obese adults in mid-life?

    DEFF Research Database (Denmark)

    Howe, Laura D; Zimmermann, Esther; Weiss, Ram

    2014-01-01

    BMI growth (7-13 years) using a multilevel model. Early-onset obesity was defined as obesity at examination for national service. OUTCOME MEASUREMENT: We defined metabolic health at the mid-life clinic as non-fasting serum cholesterol fasting glucose ...OBJECTIVE: Some obese individuals have no cardiometabolic abnormalities; they are 'metabolically healthy, but obese' (MHO). Similarly, some non-obese individuals have cardiometabolic abnormalities, that is, 'metabolically at risk, normal weight' (MANW). Previous studies have suggested that early......-onset obesity may be associated with MHO. We aimed to assess whether body mass index (BMI) in childhood and early-onset obesity are associated with MHO. SETTING: General population longitudinal cohort study, Denmark. PARTICIPANTS: From 362 200 young men (mean age 20) examined for Danish national service between...

  18. Chronic Subdural Hematoma development in Accelerated phase of Chronic Myeloid Leukaemia presenting with seizure and rapid progression course with fatal outcome

    Directory of Open Access Journals (Sweden)

    Raheja Amol

    2015-06-01

    Full Text Available Occurrence of chronic subdural hematoma (CSDH in leukemia is rare, and most reported cases occurred in relation with acute myeloid leukaemia; however, occurrence is extremely rare in accelerated phase of chronic myelogenous leukaemia (CML. Seizure as presentation of SDH development in CML cases is not reported in literature. Authors report an elderly male, who was diagnosed as CML, accelerated phase of developing SDH. Initially presented to local physician with seizure; urgent CT scan head was advised, but ignored and sensorium rapidly worsened over next day and reported to our emergency department in deeply comatose state, where imaging revealed chronic subdural hematoma with hypoxic brain injury with fatal outcome. Seizure, progressive worsening of headache, vomiting and papilloedema are harbinger of intracranial space occupying lesion and requires CT head in emergency medical department for exclusion, who are receiving treatment of haematological malignancy

  19. Simulation, measurement, and mitigation of beam instability caused by the kicker impedance in the 3-GeV rapid cycling synchrotron at the Japan Proton Accelerator Research Complex

    Science.gov (United States)

    Saha, P. K.; Shobuda, Y.; Hotchi, H.; Harada, H.; Hayashi, N.; Kinsho, M.; Tamura, F.; Tani, N.; Yamamoto, M.; Watanabe, Y.; Chin, Yong Ho; Holmes, J. A.

    2018-02-01

    The transverse impedance of eight extraction pulsed kicker magnets is a strong beam instability source in the 3-GeV rapid cycling synchrotron (RCS) at the Japan Proton Accelerator Research Complex. Significant beam instability occurs even at half of the designed 1 MW beam power when the chromaticity (ξ ) is fully corrected for the entire acceleration cycle by using ac sextupole (SX) fields. However, if ξ is fully corrected only at the injection energy by using dc SX fields, the beam is stable. In order to study realistic beam instability scenarios, including the effect of space charge and to determine practical measures to accomplish 1 MW beam power, we enhance the orbit particle tracking code to incorporate all realistic time-dependent machine parameters, including the time dependence of the impedance itself. The beam stability properties beyond 0.5 MW beam power are found to be very sensitive to a number of parameters in both simulations and measurements. In order to stabilize a beam at 1 MW beam power, two practical measures based on detailed and systematic simulation studies are determined, namely, (i) proper manipulation of the betatron tunes during acceleration and (ii) reduction of the dc SX field to reduce the ξ correction even at injection. The simulation results are well reproduced by measurements, and, as a consequence, an acceleration to 1 MW beam power is successfully demonstrated. In this paper, details of the orbit simulation and the corresponding experimental results up to 1 MW of beam power are presented. To further increase the RCS beam power, beam stability issues and possible measures beyond 1 MW beam power are also considered.

  20. Soy isoflavone exposure through all life stages accelerates 17β-estradiol-induced mammary tumor onset and growth, yet reduces tumor burden, in ACI rats.

    Science.gov (United States)

    Möller, Frank Josef; Pemp, Daniela; Soukup, Sebastian T; Wende, Kathleen; Zhang, Xiajie; Zierau, Oliver; Muders, Michael H; Bosland, Maarten C; Kulling, Sabine E; Lehmann, Leane; Vollmer, Günter

    2016-08-01

    There is an ongoing debate whether the intake of soy-derived isoflavones (sISO) mediates beneficial or adverse effects with regard to breast cancer risk. Therefore, we investigated whether nutritional exposure to a sISO-enriched diet from conception until adulthood impacts on 17β-estradiol (E2)-induced carcinogenesis in the rat mammary gland (MG). August-Copenhagen-Irish (ACI) rats were exposed to dietary sISO from conception until postnatal day 285. Silastic tubes containing E2 were used to induce MG tumorigenesis. Body weight, food intake, and tumor growth were recorded weekly. At necropsy, the number, position, size, and weight of each tumor were determined. Plasma samples underwent sISO analysis, and the morphology of MG was analyzed. Tumor incidence and multiplicity were reduced by 20 and 56 %, respectively, in the sISO-exposed rats compared to the control rats. Time-to-tumor onset was shortened from 25 to 20 weeks, and larger tumors developed in the sISO-exposed rats. The histological phenotype of the MG tumors was independent of the sISO diet received, and it included both comedo and cribriform phenotypes. Morphological analyses of the whole-mounted MGs also showed no diet-dependent differences. Lifelong exposure to sISO reduced the overall incidence of MG carcinomas in ACI rats, although the time-to-tumor was significantly shortened.

  1. Sudden Onset, Rapidly Expansile, Cervical Cystic Hygroma in an Adult: A Rare Case with Unusual Presentation and Extensive Review of the Literature

    Directory of Open Access Journals (Sweden)

    Vivek Dokania

    2017-01-01

    Full Text Available Cystic hygroma (CH is a benign infiltrative malformation of the lymphatic channels. We report a case of a 28-year-old Indian female who presented with rapidly enlarging right sided neck swelling over the posterior triangle since 5 days. Complete resection of CH is sometimes not amenable because of its infiltrative nature and involvement of surrounding vital structures. However, in our patient successful complete surgical resection was undertaken. The MRI findings of our patient were consistent with brachial cleft cyst; this posed a challenge in the diagnosis of CH. The histopathological analysis of the resected mass confirmed CH. CH is rare in adults and such an acute presentation is exceptionally atypical. History of prior trauma and infection are known etiological factors for adult CH; these were conspicuously absent in our patient. CH should be considered in the differentials of rapidly enlarging cystic swelling of posterior region of neck in adults. Optimal and timely management is necessary to achieve a favorable prognosis. Therefore, we report a case of rapidly enlarging cervical CH in an adult along with extensive literature review to have a better understanding regarding epidemiology, etiopathogenesis, clinical presentation, optimal management, and prognosis of such a rare entity in adults.

  2. Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

    Science.gov (United States)

    List, J.H.; Sallenger, A.H.; Hansen, M.E.; Jaffe, B.E.

    1997-01-01

    The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

  3. WE-DE-BRA-08: A Linear Accelerator Target Allowing Rapid Switching Between Treatment and High-Contrast Imaging Modes

    Energy Technology Data Exchange (ETDEWEB)

    Yewondwossen, M; Robar, J; Parsons, D [Dalhousie University, Halifax, NS (Canada)

    2016-06-15

    Purpose: During radiotherapy treatment, lung tumors can display substantial respiratory motion. This motion usually necessitates enlarged treatment margins to provide full tumour coverage. Unfortunately, these margins limit the dose that can be prescribed for tumour control and cause complications to normal tissue. Options for real-time methods of direct detection of tumour position, and particularly those that obviate the need for inserted fiducial markers, are limited. We propose a method of tumor tracking without implanted fiducial markers using a novel fast switching-target that toggles between a FFF copper/tungsten therapy mode and a FFF low-Z target mode for imaging. In this work we demonstrate proof-of-concept of this new technology. Methods: The prototype includes two targets: i) a FFF copper/tungsten target equivalent to that in the Varian 2100 EX 6 MV, and ii) a low-Z (carbon) target with a thickness of 110% of continuous slowing down approximation range (CSDA) at 7 MeV. The two targets can be exchanged with a custom made linear slide and motor-driven actuator. The usefulness of the switching-target concept is demonstrated through experimental BEV Planar images acquired with continual treatment and imaging at a user-defined period. Results: The prototype switching-target demonstrates that two recent advances in linac technology (FFF target for therapy and low-Z target) can be combined with synergy. The switching-target approach offers the capacity for rapid switching between treatment and high-contrast imaging modes, allowing intrafractional tracking, as demonstrated in this work with dynamic breathing phantom. By using a single beam-line, the design is streamlined and may obviate the need for an auxiliary imaging system (e.g., kV OBI.) Conclusion: This switching-target approach is a feasible combination of two current advances in linac technology (FFF target for therapy and a FFF low-Z target) allowing new options in on-line IGRT.

  4. Accelerated Combinatorial High Throughput Star Polymer Synthesis via a Rapid One-Pot Sequential Aqueous RAFT (rosa-RAFT) Polymerization Scheme.

    Science.gov (United States)

    Cosson, Steffen; Danial, Maarten; Saint-Amans, Julien Rosselgong; Cooper-White, Justin J

    2017-04-01

    Advanced polymerization methodologies, such as reversible addition-fragmentation transfer (RAFT), allow unprecedented control over star polymer composition, topology, and functionality. However, using RAFT to produce high throughput (HTP) combinatorial star polymer libraries remains, to date, impracticable due to several technical limitations. Herein, the methodology "rapid one-pot sequential aqueous RAFT" or "rosa-RAFT," in which well-defined homo-, copolymer, and mikto-arm star polymers can be prepared in very low to medium reaction volumes (50 µL to 2 mL) via an "arm-first" approach in air within minutes, is reported. Due to the high conversion of a variety of acrylamide/acrylate monomers achieved during each successive short reaction step (each taking 3 min), the requirement for intermediary purification is avoided, drastically facilitating and accelerating the star synthesis process. The presented methodology enables RAFT to be applied to HTP polymeric bio/nanomaterials discovery pipelines, in which hundreds of complex polymeric formulations can be rapidly produced, screened, and scaled up for assessment in a wide range of applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Fred: a GPU-accelerated fast-Monte Carlo code for rapid treatment plan recalculation in ion beam therapy

    Science.gov (United States)

    Schiavi, A.; Senzacqua, M.; Pioli, S.; Mairani, A.; Magro, G.; Molinelli, S.; Ciocca, M.; Battistoni, G.; Patera, V.

    2017-09-01

    Ion beam therapy is a rapidly growing technique for tumor radiation therapy. Ions allow for a high dose deposition in the tumor region, while sparing the surrounding healthy tissue. For this reason, the highest possible accuracy in the calculation of dose and its spatial distribution is required in treatment planning. On one hand, commonly used treatment planning software solutions adopt a simplified beam-body interaction model by remapping pre-calculated dose distributions into a 3D water-equivalent representation of the patient morphology. On the other hand, Monte Carlo (MC) simulations, which explicitly take into account all the details in the interaction of particles with human tissues, are considered to be the most reliable tool to address the complexity of mixed field irradiation in a heterogeneous environment. However, full MC calculations are not routinely used in clinical practice because they typically demand substantial computational resources. Therefore MC simulations are usually only used to check treatment plans for a restricted number of difficult cases. The advent of general-purpose programming GPU cards prompted the development of trimmed-down MC-based dose engines which can significantly reduce the time needed to recalculate a treatment plan with respect to standard MC codes in CPU hardware. In this work, we report on the development of fred, a new MC simulation platform for treatment planning in ion beam therapy. The code can transport particles through a 3D voxel grid using a class II MC algorithm. Both primary and secondary particles are tracked and their energy deposition is scored along the trajectory. Effective models for particle-medium interaction have been implemented, balancing accuracy in dose deposition with computational cost. Currently, the most refined module is the transport of proton beams in water: single pencil beam dose-depth distributions obtained with fred agree with those produced by standard MC codes within 1-2% of the

  6. Results of a multinational study suggest the need for rapid diagnosis and early antiviral treatment at the onset of herpetic meningoencephalitis

    DEFF Research Database (Denmark)

    Erdem, Hakan; Cag, Yasemin; Ozturk-Engin, Derya

    2015-01-01

    survived, with sequelae. Age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.05), Glasgow Coma Scale score (OR, 0.84; 95% CI, 0.77 to 0.93), and symptomatic periods of 2 to 7 days (OR, 1.80; 95% CI, 1.16 to 2.79) and >7 days (OR, 3.75; 95% CI, 1.72 to 8.15) until the commencement...... of treatment predicted unfavorable outcomes. The outcome in HME patients is related to a combination of therapeutic and host factors. This study suggests that rapid diagnosis and early administration of antiviral treatment in HME patients are keys to a favorable outcome....

  7. Acceleration theorems

    International Nuclear Information System (INIS)

    Palmer, R.

    1994-06-01

    Electromagnetic fields can be separated into near and far components. Near fields are extensions of static fields. They do not radiate, and they fall off more rapidly from a source than far fields. Near fields can accelerate particles, but the ratio of acceleration to source fields at a distance R, is always less than R/λ or 1, whichever is smaller. Far fields can be represented as sums of plane parallel, transversely polarized waves that travel at the velocity of light. A single such wave in a vacuum cannot give continuous acceleration, and it is shown that no sums of such waves can give net first order acceleration. This theorem is proven in three different ways; each method showing a different aspect of the situation

  8. HIV Cell-to-Cell Spread Results in Earlier Onset of Viral Gene Expression by Multiple Infections per Cell.

    Directory of Open Access Journals (Sweden)

    Mikaël Boullé

    2016-11-01

    Full Text Available Cell-to-cell spread of HIV, a directed mode of viral transmission, has been observed to be more rapid than cell-free infection. However, a mechanism for earlier onset of viral gene expression in cell-to-cell spread was previously uncharacterized. Here we used time-lapse microscopy combined with automated image analysis to quantify the timing of the onset of HIV gene expression in a fluorescent reporter cell line, as well as single cell staining for infection over time in primary cells. We compared cell-to-cell spread of HIV to cell-free infection, and limited both types of transmission to a two-hour window to minimize differences due to virus transit time to the cell. The mean time to detectable onset of viral gene expression in cell-to-cell spread was accelerated by 19% in the reporter cell line and by 35% in peripheral blood mononuclear cells relative to cell-free HIV infection. Neither factors secreted by infected cells, nor contact with infected cells in the absence of transmission, detectably changed onset. We recapitulated the earlier onset by infecting with multiple cell-free viruses per cell. Surprisingly, the acceleration in onset of viral gene expression was not explained by cooperativity between infecting virions. Instead, more rapid onset was consistent with a model where the fastest expressing virus out of the infecting virus pool sets the time for infection independently of the other co-infecting viruses.

  9. Beam loss reduction by injection painting in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    H. Hotchi

    2012-04-01

    Full Text Available The 3-GeV rapid cycling synchrotron (RCS of the Japan Proton Accelerator Research Complex was commissioned in October 2007. Via the initial beam tuning and a series of underlying beam studies with low-intensity beams, since December 2009, we have intermittently been performing beam tuning experiments with higher-intensity beams including the injection painting technique. By optimizing the injection painting parameters, we have successfully achieved a 420 kW-equivalent output intensity at a low-level intensity loss of less than 1%. Also the corresponding numerical simulation well reproduced the observed painting parameter dependence on the beam loss, and captured a characteristic behavior of the high-intensity beam in the injection painting process. In this paper, we present the experimental results obtained in the course of the RCS beam power ramp-up, especially on the beam loss reduction achieved by employing the injection painting, together with the numerical simulation results.

  10. Direct observation of the phase space footprint of a painting injection in the Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    2009-04-01

    Full Text Available The 3 GeV Rapid Cycling Synchrotron (RCS at Japan Proton Accelerator Research Complex is nearly at the operational stage with regard to the beam commissioning aspects. Recently, the design painting injection study has been commenced with the aim of high output beam power at the extraction. In order to observe the phase space footprint of the painting injection, a method was developed utilizing a beam position monitor (BPM in the so-called single pass mode. The turn-by-turn phase space coordinates of the circulating beam directly measured using a pair of BPMs entirely positioned in drift space, and the calculated transfer matrices from the injection point to the pair of BPMs with several successive turns were used together in order to obtain the phase space footprint of the painting injection. There are two such pairs of BPMs placed in two different locations in the RCS, the results from which both agreed and were quite consistent with what was expected.

  11. Direct observation of the phase space footprint of a painting injection in the Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex

    Science.gov (United States)

    Saha, P. K.; Shobuda, Y.; Hotchi, H.; Hayashi, N.; Takayanagi, T.; Harada, H.; Irie, Y.

    2009-04-01

    The 3 GeV Rapid Cycling Synchrotron (RCS) at Japan Proton Accelerator Research Complex is nearly at the operational stage with regard to the beam commissioning aspects. Recently, the design painting injection study has been commenced with the aim of high output beam power at the extraction. In order to observe the phase space footprint of the painting injection, a method was developed utilizing a beam position monitor (BPM) in the so-called single pass mode. The turn-by-turn phase space coordinates of the circulating beam directly measured using a pair of BPMs entirely positioned in drift space, and the calculated transfer matrices from the injection point to the pair of BPMs with several successive turns were used together in order to obtain the phase space footprint of the painting injection. There are two such pairs of BPMs placed in two different locations in the RCS, the results from which both agreed and were quite consistent with what was expected.

  12. Measurements of fireball onset

    Science.gov (United States)

    Scheiner, Brett; Barnat, Edward V.; Baalrud, Scott D.; Hopkins, Matthew M.; Yee, Benjamin T.

    2018-04-01

    Laser-based measurements of the characteristic features of fireball onset and stabilization in response to a stepped voltage applied to an anode immersed in a low pressure (100 mTorr) helium afterglow are reported. These include spatial and temporal evolution of metastable species, electron density, and electric field magnitude as measured by planar laser induced fluorescence, laser-collision induced fluorescence, and laser-induced fluorescence-dip spectroscopy, respectively. These measurements are found to be in qualitative agreement with recent particle-in-cell simulations and theoretical models [Scheiner et al., Phys. Plasmas 24, 113520 (2017)]. The measurements validate the simulations and models in which fireball onset was predicted to follow from the trapping of electrons born from electron impact ionization within a potential well created by a buildup of ions in the sheath. The experimental measurements also demonstrate transient features following the onset that were not present in previous simulations. New simulation results are presented which demonstrate that these features are associated with the abruptness of the voltage step used to initiate fireball onset. An abrupt step in the anode bias causes rapid displacement of ions and an associated plasma potential response following the sheath and fireball expansion.

  13. SU-F-T-284: The Effect of Linear Accelerator Output Variation On the Quality of Patient Specific Rapid Arc Verification Plans

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, G; Cao, F; Szpala, S; Kohli, K [Fraser Valley Cancer Centre, BC Cancer Agency, Surrey, British Columbia (Canada)

    2016-06-15

    Purpose: The aim of the current study is to investigate the effect of machine output variation on the delivery of the RapidArc verification plans. Methods: Three verification plans were generated using Eclipse™ treatment planning system (V11.031) with plan normalization value 100.0%. These plans were delivered on the linear accelerators using ArcCHECK− device, with machine output 1.000 cGy/MU at calibration point. These planned and delivered dose distributions were used as reference plans. Additional plans were created in Eclipse− with normalization values ranging 92.80%–102% to mimic the machine output ranging 1.072cGy/MU-0.980cGy/MU, at the calibration point. These plans were compared against the reference plans using gamma indices (3%, 3mm) and (2%, 2mm). Calculated gammas were studied for its dependence on machine output. Plans were considered passed if 90% of the points satisfy the defined gamma criteria. Results: The gamma index (3%, 3mm) was insensitive to output fluctuation within the output tolerance level (2% of calibration), and showed failures, when the machine output exceeds ≥3%. Gamma (2%, 2mm) was found to be more sensitive to the output variation compared to the gamma (3%, 3mm), and showed failures, when output exceeds ≥1.7%. The variation of the gamma indices with output variability also showed dependence upon the plan parameters (e.g. MLC movement and gantry rotation). The variation of the percentage points passing gamma criteria with output variation followed a non-linear decrease beyond the output tolerance level. Conclusion: Data from the limited plans and output conditions showed that gamma (2%, 2mm) is more sensitive to the output fluctuations compared to Gamma (3%,3mm). Work under progress, including detail data from a large number of plans and a wide range of output conditions, may be able to conclude the quantitative dependence of gammas on machine output, and hence the effect on the quality of delivered rapid arc plans.

  14. Impulsive ion acceleration in earth's outer magnetosphere

    International Nuclear Information System (INIS)

    Baker, D.N.; Belian, R.D.

    1985-01-01

    Considerable observational evidence is found that ions are accelerated to high energies in the outer magnetosphere during geomagnetic disturbances. The acceleration often appears to be quite impulsive causing temporally brief (10's of seconds), very intense bursts of ions in the distant plasma sheet as well as in the near-tail region. These ion bursts extend in energy from 10's of keV to over 1 MeV and are closely associated with substorm expansive phase onsets. Although the very energetic ions are not of dominant importance for magnetotail plasma dynamics, they serve as an important tracer population. Their absolute intensity and brief temporal appearance bespeaks a strong and rapid acceleration process in the near-tail, very probably involving large induced electric fields substantially greater than those associated with cross-tail potential drops. Subsequent to their impulsive acceleration, these ions are injected into the outer trapping regions forming ion ''drift echo'' events, as well as streaming tailward away from their acceleration site in the near-earth plasma sheet. Most auroral ion acceleration processes occur (or are greatly enhanced) during the time that these global magnetospheric events are occurring in the magnetotail. A qualitative model relating energetic ion populations to near-tail magnetic reconnection at substorm onset followed by global redistribution is quite successful in explaining the primary observational features. Recent measurements of the elemental composition and charge-states have proven valuable for showing the source (solar wind or ionosphere) of the original plasma population from which the ions were accelerated

  15. Japan Accelerator Conference

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    At the international level, the high energy accelerator scene evolves rapidly and the International Conference on High Energy Accelerators is where its strong pulse can best be felt. This year, the Conference was held for the first time in Japan, with the 14th meeting in the series having been hosted in August by the Japanese KEK National Laboratory for High Energy Physics, Tsukuba. The venue was a recognition of the premier accelerator physics and technology status achieved by this diligent nation

  16. Japan Accelerator Conference

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-11-15

    At the international level, the high energy accelerator scene evolves rapidly and the International Conference on High Energy Accelerators is where its strong pulse can best be felt. This year, the Conference was held for the first time in Japan, with the 14th meeting in the series having been hosted in August by the Japanese KEK National Laboratory for High Energy Physics, Tsukuba. The venue was a recognition of the premier accelerator physics and technology status achieved by this diligent nation.

  17. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  18. Laser acceleration

    International Nuclear Information System (INIS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-01-01

    The fundamental idea of LaserWakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wake fields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ∼ c and ultra fastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nano materials is also emerging.

  19. Accelerating dynamic genetic conservation efforts: Use of FT-IR spectroscopy for the rapid identification of trees resistant to destructive pathogens

    Science.gov (United States)

    C. Villari; R.A. Sniezko; L.E. Rodriguez-Saona; P. Bonello

    2017-01-01

    A strong focus on tree germplasm that can resist threats such as non-native insects and pathogens, or a changing climate, is fundamental for successful genetic conservation efforts. However, the unavailability of tools for rapid screening of tree germplasm for resistance to critical pathogens and insect pests is becoming an increasingly serious bottleneck. Here we...

  20. Can Accelerators Accelerate Learning?

    International Nuclear Information System (INIS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-01-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  1. Can Accelerators Accelerate Learning?

    Science.gov (United States)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  2. Rapid detonation initiation by sparks in a short duct: a numerical study

    Science.gov (United States)

    Hu, Z. M.; Dou, H. S.; Khoo, B. C.

    2010-06-01

    Rapid onset of detonation can efficiently increase the working frequency of a pulse detonation engine (PDE). In the present study, computations of detonation initiation in a duct are conducted to investigate the mechanisms of detonation initiation. The governing equations are the Euler equations and the chemical kinetic model consists of 19 elementary reactions and nine species. Different techniques of initiation have been studied for the purpose of accelerating detonation onset with a relatively weak ignition energy. It is found that detonation ignition induced by means of multiple sparks is applicable to auto-ignition for a PDE. The interaction among shock waves, flame fronts and the strip of pre-compressed fresh (unburned) mixture plays an important role in rapid onset of detonation.

  3. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  4. Linear Accelerators

    International Nuclear Information System (INIS)

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics

  5. Accelerator Service

    International Nuclear Information System (INIS)

    Champelovier, Y.; Ferrari, M.; Gardon, A.; Hadinger, G.; Martin, J.; Plantier, A.

    1998-01-01

    Since the cessation of the operation of hydrogen cluster accelerator in July 1996, four electrostatic accelerators were in operation and used by the peri-nuclear teams working in multidisciplinary collaborations. These are the 4 MV Van de Graaff accelerator, 2,5 MV Van de Graaff accelerator, 400 kV ion implanter as well as the 120 kV isotope separator

  6. FFAGS for muon acceleration

    International Nuclear Information System (INIS)

    Berg, J. Scott; Kahn, Stephen; Palmer, Robert; Trbojevic, Dejan; Johnstone, Carol; Keil, Eberhard; Aiba, Masamitsu; Machida, Shinji; Mori, Yoshiharu; Ogitsu, Toru; Ohmori, Chihiro; Sessler, Andrew; Koscielniak, Shane

    2003-01-01

    Due to their finite lifetime, muons must be accelerated very rapidly. It is challenging to make the magnets ramp fast enough to accelerate in a synchrotron, and accelerating in a linac is very expensive. One can use a recirculating accelerator (like CEBAF), but one needs a different arc for each turn, and this limits the number of turns one can use to accelerate, and therefore requires significant amounts of RF to achieve the desired energy gain. An alternative method for muon acceleration is using a fixed field alternating gradient (FFAG) accelerator. Such an accelerator has a very large energy acceptance (a factor of two or three), allowing one to use the same arc with a magnetic field that is constant over time. Thus, one can in principle make as many turns as one can tolerate due to muon decay, therefore reducing the RF cost without increasing the arc cost. This paper reviews the current status of research into the design of FFAGs for muon acceleration. Several current designs are described and compared. General design considerations are also discussed

  7. Plasma based accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  8. Rapid Identification and Quantification of Natural Antioxidants in the Seeds of Rhubarb from Different Habitats in China Using Accelerated Solvent Extraction and HPLC-DAD-ESI-MSn-DPPH Assay.

    Science.gov (United States)

    Tan, Liang; Geng, Dan-dan; Hu, Feng-zu; Dong, Qi

    2016-01-01

    In this study, the 10 accessions of rhubarb seeds from different habitats in China were investigated. Lipids were removed using petroleum ether, and the effective components were then separated using accelerated solvent extraction with 80% aqueous methanol. An off-line 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method was used as the marker to evaluate the total antioxidant capability of extracts. On-line high-performance liquid chromatography-diode-array detectors-electrospray ionization-tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) and HPLC-DAD-DPPH assays were developed for rapid identification and quantification of individual free-radical scavengers in extracts of rhubarb seeds. Ten free-radical scavengers from methanolic extracts of the rhubarb seeds were screened, five of which were identified and quantitatively analyzed: epicatechin, myricetin, hyperoside, quercitrin and quercetin. All were identified in rhubarb seeds for the first time and can be regarded as the major potent antioxidants in rhubarb seeds due to representing most of the total free-radical scavenging activity. Preliminary analysis of structures was performed for another five antioxidants. Based on our validation results, the developed method can be used for rapid separation, convenient identification and quantification of the multiple antioxidative constituents in rhubarb seeds, featuring good quantification parameters, accuracy and precision. The results are important to clarify the material basis and therapeutic mechanism of rhubarb seeds. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. The project SPES at LNL: Accelerator challenges

    Indian Academy of Sciences (India)

    accelerator driven system for waste transmutation. .... a 30 mA (equivalent to 3 MW power), cw proton beam, with high reliability required by the ADS .... maximum achievable surface electric field, related to the onset of field emission, and since.

  10. KEK digital accelerator

    Directory of Open Access Journals (Sweden)

    T. Iwashita

    2011-07-01

    Full Text Available The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  11. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  12. The financial impact of the incorporation of IMRT and RapidArc™ techniques on shielding calculation of a linear accelerator; O impacto financeiro da incorporacao das tecnicas de IMRT e RapidArc™ no calculo de blindagem de um acelerador linear

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maira R.; Silveira, Thiago B.; Garcia, Paulo L.; Trindade, Cassia; Martins, Lais P.; Batista, Delano V.S., E-mail: mairafisica@gmail.com [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil)

    2013-08-15

    Given the new methodology introduced in the shielding calculation due to recent modulated techniques in radiotherapy treatment, it became necessary to evaluate the impact of changes in the accelerator routine using such techniques. Based on a group of 30 patients from the National Cancer Institute (INCA) the workload multiplier factors for intensity modulated radiotherapy (IMRT factor) and for RapidArc™ (RA factor) were established. Four different routines in a 6 MV generic accelerator were proposed to estimate the impact of these modified workloads in the building cost of the secondary barriers. The results indicate that if 50% of patients are treating with IMRT, the secondary barrier becomes 14,1% more expensive than the barrier calculated for conformal treatments exclusive. While RA, in the same proportion, leads to a barrier only 3,7% more expensive. Showing that RA can, while reducing treatment time, increase the proportion of patients treated with modulation technique, without increasing the cost of the barrier, when compared with IMRT. (author)

  13. Adult onset tic disorders

    OpenAIRE

    Chouinard, S.; Ford, B.

    2000-01-01

    BACKGROUND—Tic disorders presenting during adulthood have infrequently been described in the medical literature. Most reports depict adult onset secondary tic disorders caused by trauma, encephalitis, and other acquired conditions. Only rare reports describe idiopathic adult onset tic disorders, and most of these cases represent recurrent childhood tic disorders.
OBJECTIVE—To describe a large series of patients with tic disorders presenting during adulthood, to compare cl...

  14. SSC accelerator availability allocation

    International Nuclear Information System (INIS)

    Dixon, K.T.; Franciscovich, J.

    1991-03-01

    Superconducting Super Collider (SSC) operational availability is an area of major concern, judged by the Central Design Group to present such risk that use of modern engineering tools would be essential to program success. Experience has shown that as accelerator beam availability falls below about 80%, efficiency of physics experiments degrades rapidly due to inability to maintain adequate coincident accelerator and detector operation. For this reason, the SSC availability goal has been set at 80%, even though the Fermi National Accelerator Laboratory accelerator, with a fraction of the SSC's complexity, has only recently approached that level. This paper describes the allocation of the top-level goal to part-level reliability and maintainability requirements, and it gives the results of parameter sensitivity studies designed to help identify the best approach to achieve the needed system availability within funding and schedule constraints. 1 ref., 12 figs., 4 tabs

  15. Beam loss caused by edge focusing of injection bump magnets and its mitigation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    H. Hotchi

    2016-01-01

    Full Text Available In the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, transverse injection painting is utilized not only to suppress space-charge induced beam loss in the low energy region but also to mitigate foil scattering beam loss during charge-exchange injection. The space-charge induced beam loss is well minimized by the combination of modest transverse painting and full longitudinal painting. But, for sufficiently mitigating the foil scattering part of beam loss, the transverse painting area has to be further expanded. However, such a wide-ranging transverse painting had not been realized until recently due to beta function beating caused by edge focusing of pulsed injection bump magnets during injection. This beta function beating additionally excites random betatron resonances through a distortion of the lattice superperiodicity, and its resultant deterioration of the betatron motion stability causes significant extra beam loss when expanding the transverse painting area. To solve this issue, we newly installed pulse-type quadrupole correctors to compensate the beta function beating. This paper presents recent experimental results on this correction scheme for suppressing the extra beam loss, while discussing the beam loss and its mitigation mechanisms with the corresponding numerical simulations.

  16. SHEAR ACCELERATION IN EXPANDING FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, F. M. [ZAH, Institut für Theoretische Astrophysik, Universität Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Duffy, P., E-mail: frank.rieger@mpi-hd.mpg.de, E-mail: peter.duffy@ucd.ie [University College Dublin, Belfield, Dublin 4 (Ireland)

    2016-12-10

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets from active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi–Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge line, and limb-brightening).

  17. Electrostatic accelerators

    OpenAIRE

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  18. Electrostatic accelerators

    CERN Document Server

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  19. Accelerator development

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

  20. RECIRCULATING ACCELERATION

    International Nuclear Information System (INIS)

    BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.

    2000-01-01

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous

  1. LIBO accelerates

    CERN Multimedia

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  2. Accelerating Inspire

    CERN Document Server

    AUTHOR|(CDS)2266999

    2017-01-01

    CERN has been involved in the dissemination of scientific results since its early days and has continuously updated the distribution channels. Currently, Inspire hosts catalogues of articles, authors, institutions, conferences, jobs, experiments, journals and more. Successful orientation among this amount of data requires comprehensive linking between the content. Inspire has lacked a system for linking experiments and articles together based on which accelerator they were conducted at. The purpose of this project has been to create such a system. Records for 156 accelerators were created and all 2913 experiments on Inspire were given corresponding MARC tags. Records of 18404 accelerator physics related bibliographic entries were also tagged with corresponding accelerator tags. Finally, as a part of the endeavour to broaden CERN's presence on Wikipedia, existing Wikipedia articles of accelerators were updated with short descriptions and links to Inspire. In total, 86 Wikipedia articles were updated. This repo...

  3. The oxidation of SO2 by NO2(g) at the air-water interface of aquated aerosol: implications for the rapid onset of haze-aerosol events in China

    Science.gov (United States)

    Li, L.; Colussi, A. J.; Hoffmann, M. R.

    2017-12-01

    Aqueous phase chemistry plays a vital role in the global atmosphere. The importance of heterogeneous chemistry has been recently underscored by the severe haze-fog pollution episodes experienced in Chinese megacities. A key finding is that despite reduced photochemistry during the wintertime haze events, the oxidation of S(IV) into sulfate aerosol occurs rapidly in spite of the low levels of ozone and H2O2. Field observations suggest that NO2 could serve as a suitable oxidant of S(IV) during the events under neutral pH conditions. However, the haze aerosols are mostly acidic. Furthermore, the air-water interface is more acidic than bulk-phase aquated system according to our recent findings. This work investigates the chemistry taking place as NO2(g) collides with the surface of aqueous S(IV) microdroplets as a function of pH to closely simulate actual haze aerosol events under atmospheric conditions. The reaction between NO2(g) and HSO3- (aq) is studied in situ under ambient temperature and pressure via online electrospray ionization mass spectrometry. The aqueous aerosols containing HSO3- is generated using a microjet which is exposed to NO2(g) alternatively, while the composition of the 1 nm interfacial liquid layer of the aerosol is instantaneously measured. The ratio of HSO3- to HSO4- is observed to decrease with the concomitant appearance of a strong m/z 62 signal upon NO2(g) exposure. The appearance of m/z 62 indicates the formation of NO3- via the disproportionation of NO2 (2NO2(g) + H2O (l) ⇌ H++NO3-(aq) + HONO(aq)) and thus impacts the ion-ion interactions of NO3- on the ratio of HSO3- to HSO4- in the outermost interfacial layers. Parallel experiments with NO3-(aq) additions are conducted to quantify the impact of NO3- on the the ratio, in order to unravel the contribution of NO2 to the oxidation of S(IV). After accounting for the HNO3 effect, it is concluded: (1) most NO2(g) is converted into NO3- via anion-catalyzed hydrolytic disproportionation; (2

  4. Segregation by onset asynchrony.

    Science.gov (United States)

    Hancock, P J B; Walton, L; Mitchell, G; Plenderleith, Y; Phillips, W A

    2008-08-05

    We describe a simple psychophysical paradigm for studying figure-ground segregation by onset asynchrony. Two pseudorandom arrays of Gabor patches are displayed, to left and right of fixation. Within one array, a subset of elements form a figure, such as a randomly curving path, that can only be reliably detected when their onset is not synchronized with that of the background elements. Several findings are reported. First, for most participants, segregation required an onset asynchrony of 20-40 ms. Second, detection was no better when the figure was presented first, and thus by itself, than when the background elements were presented first, even though in the latter case the figure could not be detected in either of the two successive displays alone. Third, asynchrony segregated subsets of randomly oriented elements equally well. Fourth, asynchronous onsets aligned with the path could be discriminated from those lying on the path but not aligned with it. Fifth, both transient and sustained neural activity contribute to detection. We argue that these findings are compatible with neural signaling by synchronized rate codes. Finally, schizophrenic disorganization is associated with reduced sensitivity. Thus, in addition to bearing upon basic theoretical issues, this paradigm may have clinical utility.

  5. FMIT accelerator

    International Nuclear Information System (INIS)

    Armstrong, D.D.

    1983-01-01

    A 35-MeV 100-mA cw linear accelerator is being designed by Los Alamos for use in the Fusion Materials Irradiation Test (FMIT) Facility. Essential to this program is the design, construction, and evaluation of performance of the accelerator's injector, low-energy beam transport, and radio-frequency quadrupole sections before they are shipped to the facility site. The installation and testing of some of these sections have begun as well as the testing of the rf, noninterceptive beam diagnostics, computer control, dc power, and vacuum systems. An overview of the accelerator systems and the performance to date is given

  6. Electron accelerator

    International Nuclear Information System (INIS)

    Abramyan.

    1981-01-01

    The USSR produces an electron accelerator family of a simple design powered straight from the mains. The specifications are given of accelerators ELITA-400, ELITA-3, ELT-2, TEUS-3 and RIUS-5 with maximum electron energies of 0.3 to 5 MeV, a mean power of 10 to 70 kW operating in both the pulsed and the continuous (TEUS-3) modes. Pulsed accelerators ELITA-400 and ELITA-3 and RIUS-5 in which TESLA resonance transformers are used are characterized by their compact size. (Ha)

  7. Future Accelerator Magnet Needs

    International Nuclear Information System (INIS)

    Devred, Arnaud; Gourlay, Stephen A.; Yamamoto, Akira

    2005-01-01

    Superconducting magnet technology is continually evolving in order to meet the demanding needs of new accelerators and to provide necessary upgrades for existing machines. A variety of designs are now under development, including high fields and gradients, rapid cycling and novel coil configurations. This paper presents a summary of R and D programs in the EU, Japan and the USA. A performance comparison between NbTi and Nb 3 Sn along with fabrication and cost issues are also discussed

  8. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  9. Late-Onset Asthma

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli

    2017-01-01

    Late-onset asthma is common, associated with poor outcome, underdiagnosed and undertreated, possibly due to the modifying effect of ageing on disease expression. Although the diagnostic work-up in elderly individuals suspected of having asthma follows the same steps as in younger individuals (case......, to objectively confirm asthma. If necessary, a trial of oral or inhaled corticosteroid might be necessary. Asthma can be diagnosed when increased airflow variability is identified in a symptomatic patient, and if the patient does not have a history of exposure, primarily smoking, known to cause chronic...... obstructive pulmonary disease, the diagnosis is asthma even if the patient does not have fully reversible airflow obstruction. Pharmacological therapy in patients with late-onset asthma follows international guidelines, including treatment with the lowest effective dose of inhaled corticosteroid to minimize...

  10. Use of accelerators in the national economy

    International Nuclear Information System (INIS)

    Skrinskij, A.

    1984-01-01

    Accelerators generating beams of accelerated particles are the basic component of apparatus used in irradiation technologies. One of the basic trends in irradiation is the improvement of materials, mainly polyethylene and other plastics. Irradiation with accelerated electrons improves their mechanical properties and chemical and heat resistance. Accelerated beams are also used in cement production and in grain disinfestation. The use is being developed of synchrotron radiation for rapid analysis of mineral samples, the manufacture of integrated circuits and for other applications. (Ha)

  11. LINEAR ACCELERATOR

    Science.gov (United States)

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  12. Very early-onset schizophrenia with secondary onset tic disorder

    OpenAIRE

    Shilpa A Telgote; Shreyas Shrikant Pendharkar; Amol D Kelkar; Sachin Bhojane

    2017-01-01

    Very early-onset schizophrenia (defined as an onset of psychosis before 13 years of age) is a rare and severe form of the disorder which is clinically and neurobiologically continuous with the adult-onset disorder. It is rarely reported

  13. Very Early-onset Schizophrenia with Secondary Onset Tic Disorder.

    Science.gov (United States)

    Telgote, Shilpa A; Pendharkar, Shreyas Shrikant; Kelkar, Amol D; Bhojane, Sachin

    2017-01-01

    Very early-onset schizophrenia (defined as an onset of psychosis before 13 years of age) is a rare and severe form of the disorder which is clinically and neurobiologically continuous with the adult-onset disorder. It is rarely reported tic disorder.

  14. Genetics Home Reference: rapid-onset dystonia parkinsonism

    Science.gov (United States)

    ... making one part of a larger protein called Na+/K+ ATPase, also known as the sodium pump. This protein is critical for the normal function of nerve cells (neurons) in the brain. It transports charged atoms (ions) into ... the activity of the Na+/K+ ATPase or make the protein unstable. Studies suggest ...

  15. Rapid-onset diabetic ketoacidosis secondary to nivolumab therapy

    Directory of Open Access Journals (Sweden)

    Senhong Lee

    2018-04-01

    Full Text Available We report a case of a 67-year-old man with type 2 diabetes presented with diabetic ketoacidosis, two weeks after his first dose of nivolumab therapy for non–small-cell lung carcinoma. He was started on empagliflozin two days prior in the setting of hyperglycaemia after the initiation of nivolumab therapy. Laboratory evaluation revealed an undetectable C-peptide and a positive anti-glutamic acid decarboxylase (GAD antibody. He was treated with intravenous fluids and insulin infusion and was subsequently transitioned to subcutaneous insulin and discharged home. He subsequently has developed likely autoimmune thyroiditis and autoimmune encephalitis.

  16. Late onset globoid cell leukodystrophy.

    OpenAIRE

    Grewal, R P; Petronas, N; Barton, N W

    1991-01-01

    A 29 year old male with onset of globoid cell leukodystrophy at age 14 is described. This is the first case of enzymatically confirmed globoid cell leukodystrophy with onset of symptoms after the age of ten. This patient is unique because of the late onset and slow progression and extends the clinical spectrum of globoid cell leukodystrophy.

  17. Late onset globoid cell leukodystrophy.

    Science.gov (United States)

    Grewal, R P; Petronas, N; Barton, N W

    1991-11-01

    A 29 year old male with onset of globoid cell leukodystrophy at age 14 is described. This is the first case of enzymatically confirmed globoid cell leukodystrophy with onset of symptoms after the age of ten. This patient is unique because of the late onset and slow progression and extends the clinical spectrum of globoid cell leukodystrophy.

  18. Adult-onset tic disorders

    NARCIS (Netherlands)

    Eapen, [No Value; Lees, AJ; Lakke, JPWF; Trimble, MR; Robertson, MM

    We report on 8 patients with adult-onset motor tics and vocalisations. Three had compulsive tendencies in childhood and 3 had a family history of tics or obsessive-compulsive behaviour. In comparison with DSM-classified, younger-onset Gilles de la Tourette syndrome, adult-onset tic disorders are

  19. Late onset endophthalmitis

    Directory of Open Access Journals (Sweden)

    Abdulaziz AlHadlaq

    2016-04-01

    Full Text Available We report an extremely rare presentation of late-onset endophthalmitis in a young adult patient with an unexposed Ahmed tube implant. The implant was inserted 11 years prior to presentation. There was no history of trauma or any obvious exposure on clinical examination and the tube plate was filled with purulent material. After aqueous and vitreous tap, the patient underwent intracameral, intravitreal subconjunctival antibiotic injections and was started on systemic antibiotics with good response. Endophthalmitis associated with tube drainage device can present as late as 11 years and even without an unexposed tube.

  20. Late-onset hypogonadism

    Directory of Open Access Journals (Sweden)

    Piotr Dudek

    2017-06-01

    Full Text Available In Poland, the number of men over the age of 50 years exceeds 6 million. It is estimated that about 2-6% of this population develops symptoms of late-onset hypogonadism (LOH. In men, testosterone deficiency increases slightly with age. LOH is a clinically and biochemically defined disease of older men with serum testosterone level below the reference parameters of younger healthy men and with symptoms of testosterone deficiency, manifested by pronounced disturbances of quality of life and harmful effects on multiple organ systems. Testosterone replacement therapy may give several benefits regarding body composition, metabolic control, and psychological and sexual parameters.

  1. Accelerator microanalysis

    International Nuclear Information System (INIS)

    Tuniz, C.

    1997-01-01

    Particle accelerators have been developed more than sixty years ago to investigate nuclear and atomic phenomena. A major shift toward applications of accelerators in the study of materials structure and composition in inter-disciplinary projects has been witnessed in the last two decades. The Australian Nuclear Science and Technology Organisation (ANSTO) has developed advanced research programs based on the use of particle and photon beams. Atmospheric pollution problems are investigated at the 3 MV Van de Graff accelerator using ion beam analysis techniques to detect toxic elements in aerosol particles. High temperature superconductor and semiconductor materials are characterised using the recoil of iodine and other heavy ions produced at ANTARES, the 10-MV Tandem accelerator. A heavy-ion microprobe is presently being developed at ANTARES to map elemental concentrations of specific elements with micro-size resolution. An Accelerator mass Spectrometry (AMS) system has been developed at ANSTO for the ultra-sensitive detection of Carbon-14, Iodine-129 and other long-lived radioisotopes. This AMS spectrometer is a key instrument for climate change studies and international safeguards. ANSTO is also managing the Australian Synchrotron Research program based on facilities developed at the Photon Factory (Japan) and at the Advanced Photon Source (USA). Advanced projects in biology, materials chemistry, structural condensed matter and other disciplines are being promoted by a consortium involving Australian universities and research institutions. This paper will review recent advances in the use of particle accelerators, with a particular emphasis on applications developed at ANSTO and related to problems of international concern, such as global environmental change, public health and nuclear proliferation

  2. Ion sources for electrostatic accelerators

    International Nuclear Information System (INIS)

    Hellborg, R.

    1998-01-01

    Maybe the most important part of an electrostatic accelerator system, and also often the most tricky part is the ion source. There has been a rapid growth in activity in ion-source research and development during the last two to three decades. Some of these developments have also been of benefit to electrostatic accelerator users. In this report some of the different types of ion sources used in electrostatic accelerators are described. The list is not complete but more an overview of some of the more commonly used sources. The description is divided into two groups; positive ion sources for single stage electrostatic accelerators and negative ion sources for two stages (i.e. tandem) accelerators

  3. Investigation of an accident in a resins manufacturing site: The role of accelerator on polymerisation of methyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Casson, Valeria, E-mail: valeria.casson.moreno@gmail.com [Alma Mater Studiorum—Università di Bologna, Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Bologna (Italy); Dipartimento di Ingegneria Industriale, Via Marzolo 9, 35131 Padova (Italy); Snee, Tim, E-mail: Tim.Snee@hsl.gsi.gov.uk [Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire SK 179 JN (United Kingdom); Maschio, Giuseppe, E-mail: giuseppe.maschio@unipd.it [Dipartimento di Ingegneria Industriale, Via Marzolo 9, 35131 Padova (Italy)

    2014-04-01

    Highlights: • The accelerator produces an increase in the initial rate of polymerisation. • The accelerator increases the extent of polymerisation in certain conditions. • The accelerator decreases the induction time due to the presence of inhibitor. • Runaway reaction is more likely to occur in presence of the accelerator. • The experimental data support the hypothesis about the accident. - Abstract: This paper analyzes the effect of an accelerator on the polymerisation of methyl methacrylate (MMA). This study is based on the results of an investigation of an accident in a manufacturing site for resins located in the United Kingdom. As sequence of event to cause the accident the following was assumed: during an unattended batch process a runaway undesired polymerisation of methyl methacrylate occurred, generating rapid vaporisation of monomer, which in contact with an ignition source, led to an explosion followed by a fire. Since no initiator for the polymerisation reaction had been jet added to the blend, it was supposed that the accelerator contributed to the onset of the undesired polymerisation. The accelerator involved in the accident t has therefore been tested by differential scanning calorimetry and adiabatic calorimetry. The experimental data allowed the authors to prove the hypothesis made and to define safety ranges for the polymerisation reaction.

  4. Early onset type 2 diabetes

    DEFF Research Database (Denmark)

    Bo, A; Thomsen, R W; Nielsen, J S

    2018-01-01

    was more frequent and meeting physical activity recommendations less likely in persons with early-onset type 2 DM. CONCLUSIONS: We found a clear age-gradient, with increasing prevalence of clinical and behavioural risk factors the younger the onset age of type 2 DM. Younger persons with early-onset type 2......AIM: To examine the association between early onset of type 2 diabetes (DM) and clinical and behavioural risk factors for later diabetes complications. METHODS: We conducted a cross-sectional study of 5115 persons with incident type 2 DM enrolled during 2010-2015 in the Danish Centre for Strategic...... Research in Type 2 Diabetes-cohort. We compared risk factors at time of diagnosis among those diagnosed at ≤45 years (early-onset) with diagnosis age 46-55, 56-65 (average-onset = reference), 66-75, and >75 years (late-onset). Prevalence ratios (PRs) were computed using Poisson regression. RESULTS: Poor...

  5. Accelerator operations

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  6. CNSTN Accelerator

    International Nuclear Information System (INIS)

    Habbassi, Afifa; Trabelsi, Adel

    2010-01-01

    This project give a big idea about the measurement of the linear accelerator in the CNSTN. During this work we control dose distribution for different product. For this characterisation we have to make an installation qualification ,operational qualification,performance qualification and of course for every step we have to control temperature and the dose ,even the distribution of the last one.

  7. Accelerators course

    CERN Multimedia

    CERN. Geneva HR-RFA; Métral, E

    2006-01-01

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges

  8. Accelerator operations

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Operations of the SuperHILAC, the Bevatron/Bevalac, and the 184-inch Synchrocyclotron during the period from October 1977 to September 1978 are discussed. These include ion source development, accelerator facilities, the Heavy Ion Spectrometer System, and Bevelac biomedical operations

  9. Accelerator update

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS

  10. Accelerator update

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS has managed

  11. Intermediate Inflation or Late Time Acceleration?

    International Nuclear Information System (INIS)

    Sanyal, A.K.

    2008-01-01

    The expansion rate of intermediate inflation lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of intermediate inflation reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.

  12. Early-Onset Dementia

    DEFF Research Database (Denmark)

    Konijnenberg, Elles; Fereshtehnejad, Seyed-Mohammad; Kate, Mara Ten

    2017-01-01

    BACKGROUND: Early-onset dementia (EOD) is a rare condition, with an often atypical clinical presentation, and it may therefore be challenging to diagnose. Specialized memory clinics vary in the type of patients seen, diagnostic procedures applied, and the pharmacological treatment given. The aim...... of this study was to investigate quality-of-care indicators in subjects with EOD from 3 tertiary memory clinics in 3 European countries. METHODS: We included 1325 newly diagnosed EOD patients, ages 65 years or younger, between January 1, 2007 and December 31, 2013, from the Danish Dementia Registry...... (Rigshospitalet, Copenhagen), the Swedish Dementia Registry ("SveDem", Karolinska University Hospital, Stockholm), and the Amsterdam Dementia Cohort (VU University Medical Center). RESULTS: The frequency of EOD among all dementia patients was significantly lower in Copenhagen (410, 20%) and Stockholm (284, 21...

  13. Harmonic ratcheting for fast acceleration

    Science.gov (United States)

    Cook, N.; Brennan, J. M.; Peggs, S.

    2014-04-01

    A major challenge in the design of rf cavities for the acceleration of medium-energy charged ions is the need to rapidly sweep the radio frequency over a large range. From low-power medical synchrotrons to high-power accelerator driven subcritical reactor systems, and from fixed focus alternating gradient accelerators to rapid cycling synchrotrons, there is a strong need for more efficient, and faster, acceleration of protons and light ions in the semirelativistic range of hundreds of MeV/u. A conventional way to achieve a large, rapid frequency sweep (perhaps over a range of a factor of 6) is to use custom-designed ferrite-loaded cavities. Ferrite rings enable the precise tuning of the resonant frequency of a cavity, through the control of the incremental permeability that is possible by introducing a pseudoconstant azimuthal magnetic field. However, rapid changes over large permeability ranges incur anomalous behavior such as the "Q-loss" and "f-dot" loss phenomena that limit performance while requiring high bias currents. Notwithstanding the incomplete understanding of these phenomena, they can be ameliorated by introducing a "harmonic ratcheting" acceleration scheme in which two or more rf cavities take turns accelerating the beam—one turns on when the other turns off, at different harmonics—so that the radio frequency can be constrained to remain in a smaller range. Harmonic ratcheting also has straightforward performance advantages, depending on the particular parameter set at hand. In some typical cases it is possible to halve the length of the cavities, or to double the effective gap voltage, or to double the repetition rate. This paper discusses and quantifies the advantages of harmonic ratcheting in general. Simulation results for the particular case of a rapid cycling medical synchrotron ratcheting from harmonic number 9 to 2 show that stability and performance criteria are met even when realistic engineering details are taken into consideration.

  14. Perception of Arabidopsis AtPep peptides, but not bacterial elicitors, accelerates starvation-induced senescence

    Directory of Open Access Journals (Sweden)

    Kay eGully

    2015-01-01

    Full Text Available Members of the AtPep group of Arabidopsis endogenous peptides have frequently been reported to induce pattern-triggered immunity and to increase resistance to diverse pathogens by amplifying the innate immune response. Here, we made the surprising observation that dark-induced leaf senescence was accelerated by the presence of Peps. Adult leaves as well as leaf discs of Col-0 wild type plants showed a Pep-triggered early onset of chlorophyll breakdown and leaf yellowing whereas pepr1 pepr2 double mutant plants were insensitive. In addition, this response was dependent on ethylene signaling and inhibited by the addition of cytokinins. Notably, addition of the bacterial elicitors flg22 or elf18, both potent inducers of pattern-triggered immunity, did not provoke an early onset of leaf senescence.Continuous darkness leads to energy deprivation and starvation and therewith promotes leaf senescence. We found that continuous darkness also strongly induced PROPEP3 transcription. Moreover, Pep-perception led to a rapid induction of PAO, APG7 and APG8a, genes indispensable for chlorophyll degradation as well as autophagy, respectively, and all three hallmarks of starvation and senescence. Notably, addition of sucrose as a source of energy inhibited the Pep-triggered early onset of senescence. In conclusion, we report that Pep-perception accelerates dark/starvation-induced senescence via an early induction of chlorophyll degradation and autophagy. This represents a novel and unique characteristic of PEPR signaling, unrelated to pattern-triggered immunity.

  15. Review of ion accelerators

    International Nuclear Information System (INIS)

    Alonso, J.

    1990-06-01

    The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here

  16. Accelerators for cancer therapy

    International Nuclear Information System (INIS)

    Lennox, Arlene J.

    2000-01-01

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy

  17. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    Jonsson, Eythor Ivar

    2015-01-01

    and developing the best business ideas and support the due diligence process. Even universities are noticing that the learning experience of the action learning approach is an effective way to develop capabilities and change cultures. Accelerators related to what has historically been associated...

  18. Accelerating networks

    International Nuclear Information System (INIS)

    Smith, David M D; Onnela, Jukka-Pekka; Johnson, Neil F

    2007-01-01

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  19. Medical applications of accelerators

    CERN Document Server

    Rossi, Sandro

    1998-01-01

    At Present, about five thousands accelerators are devoted to biomedical applications. They are mainly used in radiotherapy, research and medical radioisotopes production. In this framework oncological hadron-therapy deserves particular attention since it represents a field in rapid evolution thanks to the joint efforts of laboratories with long experiences in particle physics. It is the case of CERN where the design of an optimised synchrotron for medical applications has been pursued. These lectures present these activities with particular attention to the new developments which are scientifically interesting and/or economically promising.

  20. Advanced concepts for acceleration

    International Nuclear Information System (INIS)

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations

  1. Accelerators and the Accelerator Community

    Energy Technology Data Exchange (ETDEWEB)

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  2. Accelerators and the Accelerator Community

    International Nuclear Information System (INIS)

    Malamud, Ernest; Sessler, Andrew

    2008-01-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process

  3. Proton-driven Plasma Wakefield Acceleration

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The construction of ever larger and costlier accelerator facilities has a limited future, and new technologies will be needed to push the energy frontier. Plasma wakefield acceleration is a rapidly developing field and is a promising candidate technology for future high energy colliders. We focus on the recently proposed idea of proton-driven plasma wakefield acceleration and describe the current status and plans for this approach.

  4. Preferential acceleration in collisionless supernova shocks

    International Nuclear Information System (INIS)

    Hainebach, K.; Eichler, D.; Schramm, D.

    1979-01-01

    The preferential acceleration and resulting cosmic ray abundance enhancements of heavy elements (relative to protons) are calculated in the collisionless supernova shock acceleration model described by Eichler in earlier work. Rapidly increasing enhancements up to several tens times solar ratios are obtained as a function of atomic weight over charge at the time of acceleration. For material typical of hot phase interstellar medium, good agreement is obtained with the observed abundance enhancements

  5. Accelerated Cure Project for Multiple Sclerosis

    Science.gov (United States)

    ... questions and enable an era of optimized MS treatment. Read more... The Accelerated Cure Project for MS is a non-profit, 501(c)(3) tax-exempt organization whose mission is to accelerate efforts toward a cure for multiple sclerosis by rapidly advancing research that determines its causes ...

  6. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  7. accelerating cavity

    CERN Multimedia

    On the inside of the cavity there is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  8. Cosmic ray acceleration mechanisms

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1982-09-01

    We present a brief summary of some of the most popular theories of cosmic ray acceleration: Fermi acceleration, its application to acceleration by shocks in a scattering medium, and impulsive acceleration by relativistic shocks

  9. Accelerated Profile HMM Searches.

    Directory of Open Access Journals (Sweden)

    Sean R Eddy

    2011-10-01

    Full Text Available Profile hidden Markov models (profile HMMs and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  10. Surfactants non-monotonically modify the onset of Faraday waves

    Science.gov (United States)

    Strickland, Stephen; Shearer, Michael; Daniels, Karen

    2017-11-01

    When a water-filled container is vertically vibrated, subharmonic Faraday waves emerge once the driving from the vibrations exceeds viscous dissipation. In the presence of an insoluble surfactant, a viscous boundary layer forms at the contaminated surface to balance the Marangoni and Boussinesq stresses. For linear gravity-capillary waves in an undriven fluid, the surfactant-induced boundary layer increases the amount of viscous dissipation. In our analysis and experiments, we consider whether similar effects occur for nonlinear Faraday (gravity-capillary) waves. Assuming a finite-depth, infinite-breadth, low-viscosity fluid, we derive an analytic expression for the onset acceleration up to second order in ɛ =√{ 1 / Re } . This expression allows us to include fluid depth and driving frequency as parameters, in addition to the Marangoni and Boussinesq numbers. For millimetric fluid depths and driving frequencies of 30 to 120 Hz, our analysis recovers prior numerical results and agrees with our measurements of NBD-PC surfactant on DI water. In both case, the onset acceleration increases non-monotonically as a function of Marangoni and Boussinesq numbers. For shallower systems, our model predicts that surfactants could decrease the onset acceleration. DMS-0968258.

  11. Circadian Variation Of Stroke Onset

    Directory of Open Access Journals (Sweden)

    Kamath vasantha

    2003-01-01

    Full Text Available Diurnal variations in various physiological and biochemical functions and certain pathological events like myocardial infarction and stroke have been documented. We studied prospectively one hundred and seven patients of acute onset stroke confirmed by computed tomography for the exact time of onset, risk factors and type of stroke. Patients who were unclear of time of onset and with a diagnosis of cerebral venous thrombosis or sub-arachnoid hemorrhage were excluded. Infarction was detected in 71 patients and hemorrhage in 33 patients. Men out numbered women (1:6:1. Hypertension was more frequent in hemorrhage in the morning time (5 AM-12 noon and more infarction between 12-6 pm. However there was no relation between the time of onset of stroke and various risk-factors of stroke.

  12. Rapidly alternating combination of cisplatin-based chemotherapy and hyperfractionated accelerated radiotherapy in split course for Stage IIIA and Stage IIIB non-small cell lung cancer: results of a Phase I-II study by the GOTHA group

    Energy Technology Data Exchange (ETDEWEB)

    Alberto, P.; Mermillod, B. [Hopital Cantonal Geneve, Geneva (Switzerland); Mirimanoff, R.O.; Leyvraz, S.; Nagy-Mignotte, H.; Bolla, M.; Wellmann, D.; Moro, D.; Brambilla, E. [Hopital Cantonal Universitaire, Lausanne (Switzerland)

    1995-08-01

    The prognosis of stage III non-small cell lung cancer (NSCLC) can be improved by a combination of radiotherapy (RT) and chemotherapy (CT). In this study, the GOTHA group evaluated the feasibility, tolerance, tumour response, pattern of failure and effect on survival of a combination alternating accelerated hyperfractionated (AH) RT and CT in patients with tumour stage III NSCLC. Toxic effects were leucopenia, nausea and vomiting, mucositis, diarrhoea, alopecia and peripheral neuropathy. Alternating CT and AHRT, as used in this study, were well tolerated and allowed full dose delivery within less than 12 weeks. Initial response was not predictive of survival. The survival curve is encouraging and the 5 year survival is superior to the 5% generally observed with conventionally fractionated radiotherapy. (author).

  13. Sector ring accelerator ''RESATRON''

    International Nuclear Information System (INIS)

    Schwabe, E.

    1980-01-01

    Project of sector ring accelerator RESATRON is described. The curiosity of this accelerator is the second cycle of acceleration of the beam after stripping it on the foil. In such an accelerator heavy ions with a different ratio Z to A can be accelerated. (S.B.)

  14. Multiperiodic accelerator structures for linear particle accelerators

    International Nuclear Information System (INIS)

    Tran, D.T.

    1975-01-01

    High efficiency linear accelerator structures, comprised of a succession of cylindrical resonant cavities for acceleration, are described. Coupling annular cavities are located at the periphery, each being coupled to two adjacent cylindrical cavities. (auth)

  15. Is biological aging accelerated in drug addiction?

    Science.gov (United States)

    Bachi, Keren; Sierra, Salvador; Volkow, Nora D; Goldstein, Rita Z; Alia-Klein, Nelly

    2017-02-01

    Drug-addiction may trigger early onset of age-related disease, due to drug-induced multi-system toxicity and perilous lifestyle, which remains mostly undetected and untreated. We present the literature on pathophysiological processes that may hasten aging and its relevance to addiction, including: oxidative stress and cellular aging, inflammation in periphery and brain, decline in brain volume and function, and early onset of cardiac, cerebrovascular, kidney, and liver disease. Timely detection of accelerated aging in addiction is crucial for the prevention of premature morbidity and mortality.

  16. Washington Accelerator Conference

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Highlights of the 1993 Particle Accelerator Conference, held in Washington in May, were picked out in the previous issue (page 18). Talks on the big hadron colliders reflected the sea-change in the accelerator world where the scale, complexity and cost of the front-line projects has slowed the pace of developments (not unlike the scene in particle physics itself). Speaking before the anti-SSC vote in the House of Representatives in June, Dick Briggs reviewed the situation at the SSC Superconducting Supercollider in Ellis County, Texas. The linac building is near completion and the Low Energy Booster will be ready to receive components early next year. Tunnelling for the Main Ring is advancing rapidly with four boring machines in action. Five miles of tunnel have been completed since January and the pace has now stepped up to nearly a mile each week. The superconducting magnet news is good. Following the successful initial string test of a half cell of the magnet lattice, a two-ring full cell with all associated services is being assembled. The mechanical robustness of the magnet design was confirmed when a dipole was taken to 9.7 T when cooled to 1.8 K. In the Magnet Test Lab itself, ten test stands are installed and equipped

  17. Washington Accelerator Conference

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-09-15

    Highlights of the 1993 Particle Accelerator Conference, held in Washington in May, were picked out in the previous issue (page 18). Talks on the big hadron colliders reflected the sea-change in the accelerator world where the scale, complexity and cost of the front-line projects has slowed the pace of developments (not unlike the scene in particle physics itself). Speaking before the anti-SSC vote in the House of Representatives in June, Dick Briggs reviewed the situation at the SSC Superconducting Supercollider in Ellis County, Texas. The linac building is near completion and the Low Energy Booster will be ready to receive components early next year. Tunnelling for the Main Ring is advancing rapidly with four boring machines in action. Five miles of tunnel have been completed since January and the pace has now stepped up to nearly a mile each week. The superconducting magnet news is good. Following the successful initial string test of a half cell of the magnet lattice, a two-ring full cell with all associated services is being assembled. The mechanical robustness of the magnet design was confirmed when a dipole was taken to 9.7 T when cooled to 1.8 K. In the Magnet Test Lab itself, ten test stands are installed and equipped.

  18. Accelerators of atomic particles

    International Nuclear Information System (INIS)

    Sarancev, V.

    1975-01-01

    A brief survey is presented of accelerators and methods of accelerating elementary particles. The principle of collective accelerating of elementary particles is clarified and the problems are discussed of its realization. (B.S.)

  19. Analysis of FFAG accelerators and the evolution of circular accelerators

    International Nuclear Information System (INIS)

    Laslett, J.

    1961-01-01

    After rapidly comparing circular machines with the linear accelerator and the reasons for the choice of an annular high energy and very high intensity accelerator, recent problems concerning accelerator theory are discussed, with emphasis on their physical character. The FFAG principle. The limit of the energy of FFAG cyclotron. The setting-up and interpreting of mean energy of focusing terms for a spiral FFAG synchrotron. The limiting amplitude stable near the non-linear resonance 2Q z = Q r , as well as the linear coupling resonance of Walkinshaw 2Q z = Q r . The crossed-beam accelerator. The 40 MeV electron model of MURA. Two other parts deal with linear and non-linear methods of injection and extraction using a variable disturbance applied to the magnetic field, as well as to collective effects. The interaction of the beam with the accelerating cavities and the walls. The modification of the phase oscillation equation. The influence of the beams' high frequency fields on the Nielsen longitudinal instability. (author) [fr

  20. Pitch then power: limitations to acceleration in quadrupeds

    OpenAIRE

    Williams, Sarah B.; Tan, Huiling; Usherwood, James R.; Wilson, Alan M.

    2009-01-01

    Rapid acceleration and deceleration are vital for survival in many predator and prey animals and are important attributes of animal and human athletes. Adaptations for acceleration and deceleration are therefore likely to experience strong selective pressures?both natural and artificial. Here, we explore the mechanical and physiological constraints to acceleration. We examined two elite athletes bred and trained for acceleration performance (polo ponies and racing greyhounds), when performing...

  1. Several problems in accelerator shielding study

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Hirayama, Hideo; Ban, Shuichi.

    1980-01-01

    Recently, the utilization of accelerators has increased rapidly, and the increase of accelerating energy and beam intensity is also remarkable. The studies on accelerator shielding have become important, because the amount of radiation emitted from accelerators increased, the regulation of the dose of environmental radiation was tightened, and the cost of constructing shielding rose. As the plans of constructing large accelerators have been made successively, the survey on the present state and the problems of the studies on accelerator shielding was carried out. Accelerators are classified into electron accelerators and proton accelerators in view of the studies on shielding. In order to start the studies on accelerator shielding, first, the preparation of the cross section data is indispensable. The cross sections for generating Bremsstrahlung, photonuclear reactions generating neutrons, generation of neutrons by hadrons, nuclear reaction of neutrons and generation of gamma-ray by hadrons are described. The generation of neutrons and gamma-ray as the problems of thick targets is explained. The shielding problems are complex and diversified, but in this paper, the studies on the shielding, by which basic data are obtainable, are taken up, such as beam damping and side wall shielding. As for residual radioactivity, main nuclides and the difference of residual radioactivity according to substances have been studied. (J.P.N.)

  2. Rapid charging of nickel-cadmium accumulators

    Energy Technology Data Exchange (ETDEWEB)

    Bruck, F

    1972-01-01

    Four types of charging of gas-tight Ni-Cd accumulators (a) normal; (b) accelerated; (c) rapid; and (d) ultra-rapid are described. For rapid charging, a built-in temperature sensor cuts off charging current at a prescribed point. In ultra-rapid charging, 50% charge can be attained in 3.5 min. and 25% charge within 50 sec. In the second phase of ultra-rapid charging, a surplus of oxygen is released at the positive electrode and a safety valve is provided for pressure reduction. Characteristic curves are given for various rates of charging and some data on discharge rates is also given.

  3. Post-operative Adult Onset Tic Disorder: A Rare Presentation.

    Science.gov (United States)

    Upadhyaya, Suneet Kumar; Raval, Chintan M; Sharma, Devendra Kumar; Vijayvergiya, Devendra Kumar

    2014-10-01

    Tics are rapid and repetitive muscle contractions resulting in stereotype movements and vocalizations that are experienced as involuntary. Onset before 18-year is a diagnostic criterion for tic disorders. Children and adolescents may exhibit tic behaviors after a stimulus or in response to an internal urge. Tic behaviors increase during physical or an emotional stress. Adult onset tic disorders are reported by infections, drugs, cocaine, toxins, chromosomal disorders, head injury, stroke, neurocutaneous syndromes, neurodegenerative disorders and peripheral injuries. Only few cases have yet been reported having onset after surgery though surgery brings both physical and emotional stress to the patient. We report a case of a 55-year-old lady who developed tic disorder as post-operative event of cataract surgery. Our patient had a dramatic response to haloperidol which is in contrast to all earlier reports.

  4. Dusty-Plasma Particle Accelerator

    Science.gov (United States)

    Foster, John E.

    2005-01-01

    A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the

  5. Late onset startle induced tics

    NARCIS (Netherlands)

    Tijssen, MAJ; Brown, P; Morris, HR; Lees, A

    1999-01-01

    Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor ties were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The ties developed after physical trauma or a period of undue emotional stress. Reflex ties may occur in

  6. Late onset startle induced tics

    NARCIS (Netherlands)

    Tijssen, M. A.; Brown, P.; Morris, H. R.; Lees, A.

    1999-01-01

    Three cases of late onset Gilles de la Tourette's syndrome are presented. The motor tics were mainly induced by an unexpected startling stimulus, but the startle reflex was not exaggerated. The tics developed after physical trauma or a period of undue emotional stress. Reflex tics may occur in

  7. Accelerating the Transformation of Economic Development Mode to Promote the Sable and Rapid Development of Industry%加快转变经济发展方式 推进行业平稳较快发展

    Institute of Scientific and Technical Information of China (English)

    张新民

    2012-01-01

    It is pointed out through the interpretation of the "Twelfth Five-Year Plan" of the woodworking machinery industry that the next five years is a very import period when the transformation development of woodworking machinery industry and the breakthrough development of industry transfer should be accelerated, structural adjustment and technical innovation should serve as important support for the development of woodworking machinery industry in the following five years , the change in the marked demand should be followed closely to realize the shift to new industries featuring structural optimization, advanced technology, cleanness and safety and high added value, enterprise famous brands should be expanded, strong alliance between enterprises should be promoted in order to be bigger and stronger and great importance should be attached to the soft strength construction of enterprises in terms of human resources, corporate culture and internal management to realize the long-term development of enterprises and enhance the intangible wealth for enterprise development.%对木工机械行业“十二五”规划进行解读,指出未来五年是加快木机行业转型发展、产业转移突破发展的关键五年,要坚持把结构调整和科技创新作为未来五年木机行业发展的重要支撑,要紧跟市场需求变化。向结构优化、技术先进、清洁安全、附加值高的新型产业转向,要扩大企业知名品牌,推进强强联合,做大做强,要重视企业的人力资源、企业文化、内部管理等软实力建设,增加企业发展的无形财富,实现企业长久发展。

  8. Accelerators of future generation

    International Nuclear Information System (INIS)

    Kolomenskij, A.A.

    1983-01-01

    A brief review of the prospects of development of various of types accelerator over next 10 to 15 years is given. The following directions are considered: superhign energy proton accelerators and storage rings, electron-positron colliding beams, heavy ion accelerators, medium energy, high-current proton accelerators superhigh power particle beams (electrons light- and heavy ions) for inertial fusion

  9. Future accelerator technology

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1986-05-01

    A general discussion is presented of the acceleration of particles. Upon this foundation is built a categorization scheme into which all accelerators can be placed. Special attention is devoted to accelerators which employ a wake-field mechanism and a restricting theorem is examined. It is shown how the theorem may be circumvented. Comments are made on various acceleration schemes

  10. Accelerated Characterization of Polymer Properties

    Energy Technology Data Exchange (ETDEWEB)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  11. Shock wave and flame front induced detonation in a rapid compression machine

    Science.gov (United States)

    Wang, Y.; Qi, Y.; Xiang, S.; Mével, R.; Wang, Z.

    2018-05-01

    The present study focuses on one mode of detonation initiation observed in a rapid compression machine (RCM). This mode is referred to as shock wave and flame front-induced detonation (SWFID). Experimental high-speed imaging and two-dimensional numerical simulations with skeletal chemistry are combined to unravel the dominant steps of detonation initiation under SWFID conditions. It is shown that the interaction between the shock wave generated by the end-gas auto-ignition and the spherical flame creates a region of high pressure and temperature which enables the acceleration of the flame front and the detonation onset. The experimental observation lacks adequate spatial and temporal resolution despite good reproducibility of the detonation onset. Based on the numerical results, phenomenological interpretation of the event within the framework of shock wave refraction indicates that the formation of a free-precursor shock wave at the transition between regular and irregular refraction may be responsible for detonation onset. The present results along with previous findings on shock wave reflection-induced detonation in the RCM indicate that super-knock occurs after the interaction of the shock wave generated by end-gas auto-ignition with the RCM walls, preignition flame, or another shock wave.

  12. JINR rapid communications

    International Nuclear Information System (INIS)

    1999-01-01

    The present collection of rapid communications from JINR, DUBNA, contains eight separate records on symmetry in modern physics (dedicated to the 100th anniversary of the birth of academician V.A.Fock), the double φ-meson production investigation on the Serpukhov accelerator, two-leptonic η-meson decays and SUSY without R parity, charge form factors and alpha-cluster internal structure of 12 C, increasing of muon-track reconstruction efficiency in ME1/1 Dubna prototype for the CMS/LHC, study of photon-structure function F 2 γ in the reaction e + e - → e + e - + hadrons at LEP2, jets reconstruction possibility in pAu and AuAu interactions at STAR RHIC and high-vacuum nondispersable gas absorber

  13. JINR Rapid Communications. Collection

    International Nuclear Information System (INIS)

    1994-01-01

    The present collection of rapid communications from JINR, Dubna, contains eight separate reports on Lorentz transformations with superluminal velocities, photo chromic effect in HTSC films, the investigation of hypernuclei in the Nuclotron accelerator, a new hadron jets finding algorithm in the four-dimensional velocity space, investigations of neutral particle production by relativistic nuclei on the LHE 90-channel γ-spectrometer (results and perspectives), coherent meson production in the dp → 3 HeX reaction, the relativistic projectile nuclei fragmentation and A-dependence of nucleon Fermi-momenta, energy spectra of γ-quanta from d-propane interactions at momentum P d = 1.25 GeV/c per nucleon. 86 refs., 26 figs., 4 tabs

  14. JINR rapid communications

    International Nuclear Information System (INIS)

    1999-01-01

    The present collection of rapid communications from JINR, Dubna, contains seven separate records on measurements of the total cross section difference Δσ L (np) at 1.59, 1.79, and 2.20 GeV, to the estimation of angular distributions of double charged spectator fragments in nucleus-nucleus interactions at superhigh energies, simulation dE/dx analysis results for silicon inner tracking system of ALICE set-up at LHC accelerator, high-multiplicity processes, triggering of high-multiplicity events using calorimetry, ORBIT-3.0 - a computer code for simulation and correction of the closed orbit and first turn in synchrotrons and determination of memory performance

  15. A simple and accurate onset detection method for a measured bell-shaped speed profile

    Directory of Open Access Journals (Sweden)

    Lior Botzer

    2009-06-01

    Full Text Available Motor control neuroscientists measure limb trajectories and extract the onset of the movement for a variety of purposes. Such trajectories are often aligned relative to the onset of individual movement before the features of that movement are extracted and their properties are inspected. Onset detection is performed either manually or automatically, typically by selecting a velocity threshold. Here, we present a simple onset detection algorithm that is more accurate than the conventional velocity threshold technique. The proposed method is based on a simple regression and follows the minimum acceleration with constraints model, in which the initial phase of the bell-shaped movement is modeled by a cubic power of the time. We demonstrate the performance of the suggested method and compare it to the velocity threshold technique and to manual onset detection by a group of motor control experts. The database for this comparison consists of simulated minimum jerk trajectories and recorded reaching movements.

  16. Marriage trends among Americans with childhood-onset disabilities, 1997-2013.

    Science.gov (United States)

    Tumin, Dmitry

    2016-10-01

    People with disabilities are less likely to marry than people without disabilities. Trends in marriage and assortative mating among people with disabilities have not been investigated. This study tested if marriage likelihood converged between adults with childhood-onset disabilities and their peers, and if married adults with childhood-onset disabilities became more likely to have a spouse without disabilities. U.S. data from annual National Health Interview Surveys were used to identify adults ages 18-44 surveyed between 1997 and 2013 (N = 562,229). Childhood-onset disability was defined by self-report of physical conditions limiting the respondent's activities since age marriage to a spouse without reported disabilities between adults with childhood-onset disabilities and adults without childhood-onset disabilities. Across survey years, the decline in odds of having ever married was stronger among adults with childhood-onset disabilities (OR = 0.94; 95% CI: 0.93, 0.95; p marriage among people with childhood-onset disabilities. Among adults married at the time of the survey, those with childhood-onset disabilities were less likely to have a spouse without reported disabilities. The American retreat from marriage has been accelerated among adults with childhood-onset disabilities, with high rates of in-marriage to other people with disabilities persisting in this group. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Muon Collider Progress: Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zisman, Michael S.

    2011-09-10

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 × 10{sup 34} cm{sup –2}s{sup –1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (“cooling”). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

  18. Dipolarization Fronts from Reconnection Onset

    Science.gov (United States)

    Sitnov, M. I.; Swisdak, M. M.; Merkin, V. G.; Buzulukova, N.; Moore, T. E.

    2012-12-01

    Dipolarization fronts observed in the magnetotail are often viewed as signatures of bursty magnetic reconnection. However, until recently spontaneous reconnection was considered to be fully prohibited in the magnetotail geometry because of the linear stability of the ion tearing mode. Recent theoretical studies showed that spontaneous reconnection could be possible in the magnetotail geometries with the accumulation of magnetic flux at the tailward end of the thin current sheet, a distinctive feature of the magnetotail prior to substorm onset. That result was confirmed by open-boundary full-particle simulations of 2D current sheet equilibria, where two magnetotails were separated by an equilibrium X-line and weak external electric field was imposed to nudge the system toward the instability threshold. To investigate the roles of the equilibrium X-line, driving electric field and other parameters in the reconnection onset process we performed a set of 2D PIC runs with different initial settings. The investigated parameter space includes the critical current sheet thickness, flux tube volume per unit magnetic flux and the north-south component of the magnetic field. Such an investigation is critically important for the implementation of kinetic reconnection onset criteria into global MHD codes. The results are compared with Geotail visualization of the magnetotail during substorms, as well as Cluster and THEMIS observations of dipolarization fronts.

  19. Cerebellar ataxia of early onset

    International Nuclear Information System (INIS)

    Yamashita, Sumimasa; Miyake, Shota; Yamada, Michiko; Iwamoto, Hiroko; Yamada, Kazuhiko.

    1989-01-01

    Eight cases of childhood cerebellar ataxia were reported. All these cases showed chronic cerebellar ataxia with early onset, and the other diseases of cerebellum such as infections, neoplasms and storage diseases were excluded by clinical symptoms and laboratory findings including blood counts, blood chemistry, lactate, pyruvate, ceruloplasmine, urinalysis, serum immunoglobulins, amino acid analysis in blood and urine, CSF analysis, leukocyte lysosomal enzymes, MCV, EMG, EEG and brain X-CT. Two pairs of siblings were included in this study. The clinical diagnosis were cerebellar type (5), spinocerebellar type (1), one Marinesco-Sjoegren syndrome and undetermined type (1). The age of onset was 1 to 5 years. The chief complaint was motor developmental delay in 6 cases; among them 5 patients could walk alone at the ages of 2 to 3 years'. Mental retardation was observed in 7 cases and epilepsy in 2. TRH was effective in 5 cases. The MRI study revealed that the area of medial sagittal slice of the cerebellum was reduced significantly in all cases and also that of pons was reduced in 5 cases. Different from typical adult onset spinocerebellar degenerations, most of the present cases have achieved slow developmental milestones and the clinical course was not progressive. Genetic factors are suspected in the pathogenesis of this disease in some cases. (author)

  20. Enhancing proton acceleration by using composite targets

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.

    2015-07-10

    Efficient laser ion acceleration requires high laser intensities, which can only be obtained by tightly focusing laser radiation. In the radiation pressure acceleration regime, where the tightly focused laser driver leads to the appearance of the fundamental limit for the maximum attainable ion energy, this limit corresponds to the laser pulse group velocity as well as to another limit connected with the transverse expansion of the accelerated foil and consequent onset of the foil transparency. These limits can be relaxed by using composite targets, consisting of a thin foil followed by a near critical density slab. Such targets provide guiding of a laser pulse inside a self-generated channel and background electrons, being snowplowed by the pulse, compensate for the transverse expansion. The use of composite targets results in a significant increase in maximum ion energy, compared to a single foil target case.

  1. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    CERN Multimedia

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  2. Physical processes for the onset of magnetospheric substorms

    International Nuclear Information System (INIS)

    Kan, J.R.; Akasofu, S-I.; Lee, L.C.

    1980-01-01

    There are at least three important advances in observational as well as theoretical understanding of substorm processes during the last several years; they are: (i) the 'V-shaped' potential structure for auroral acceleration, (ii) deflation as the cause of thinning of the distant plasma sheet, and (iii) interruption and subsequent diversion of the cross-tail current during the expansive phase of magnetospheric substorms. A possible chain of processes is suggested, including (i), (ii) and (iii) as vital parts, which leads to substorm onset. (Auth.)

  3. Microdischarges in DC accelerator tubes

    International Nuclear Information System (INIS)

    Eastham, D.A.; Thorn, R.

    1978-07-01

    Voltage tests on the Daresbury ceramic/titanium accelerator tube have shown that microdischarges play an important role in the conditioning process. It has been found that the voltage onset for microdischarges in a tube is dependent on the surface contamination of the electrodes and the tube geometry (in particular the tube length). This geometrical effect can be related to the trajectories of secondary ions emitted from the electrode surfaces. Sensitive diagnostic techniques have been developed to study the mass and energy distribution of ions emitted along the axis of the tube during these predischarges. The energy distribution of protons (and H - ions) can be related to the origins of the discharges in the tube. Detailed results are presented for a particular tube geometry. (author)

  4. Neutrons from medical electron accelerators

    International Nuclear Information System (INIS)

    Swanson, W.P.; McCall, R.C.

    1979-06-01

    The significant sources of photoneutrons within a linear-accelerator treatment head are identified and absolute estimates of neutron production per treatment dose are given for typical components. Measured data obtained at a variety of accelerator installations are presented and compared with these calculations. It is found that the high-Z materials within the treatment head do not significantly alter the neutron fluence, but do substantially reduce the average energy of the transmitted spectrum. Reflected neutrons from the concrete treatment room contribute to the neutron fluence, but not substantially to the patient integral dose, because of a further reduction in average energy. Absolute depth-dose distributions for realistic neutron spectra are calculated, and a rapid falloff with depth is found

  5. Accelerator development programme in India - an outlook

    International Nuclear Information System (INIS)

    Bhandari, R.K.

    2011-01-01

    With the construction of the VEC, Indus-1, Indus-2, superconducting cyclotron, superconducting heavy ion linac boosters etc. and implementation of other accelerator R and D programmes, we are now 'equipped' to take a quantum jump in the accelerator field. We have highly trained and skilled manpower that can take up challenges in this rapidly growing field both for research as well as applications. Serious planning is going on in the country to construct accelerator facilities for versatile Rare Ion Beams (RIB), powerful spallation source, advanced synchrotron source, high power beam for ADS etc. There is strong demand by the medical community for a proton/heavy ion cancer therapy facility and for accelerator-produced radioisotopes for medical diagnostics. Proliferation of accelerators in the industry field is long overdue in our country and welcome realization is coming. In this presentation a glimpse of the intended growth of accelerator field in the country will be given. Interesting challenges are there not only for the accelerator community, which has to grow, but also for the industry. Since the general trend is now to construct high intensity and high beam power accelerators - both for research as well as applications - the associated problems of radiation safety will be highlighted. (author)

  6. Childhood-compared to adolescent-onset bipolar disorder has more statistically significant clinical correlates.

    Science.gov (United States)

    Holtzman, Jessica N; Miller, Shefali; Hooshmand, Farnaz; Wang, Po W; Chang, Kiki D; Hill, Shelley J; Rasgon, Natalie L; Ketter, Terence A

    2015-07-01

    The strengths and limitations of considering childhood-and adolescent-onset bipolar disorder (BD) separately versus together remain to be established. We assessed this issue. BD patients referred to the Stanford Bipolar Disorder Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD Affective Disorders Evaluation. Patients with childhood- and adolescent-onset were compared to those with adult-onset for 7 unfavorable bipolar illness characteristics with replicated associations with early-onset patients. Among 502 BD outpatients, those with childhood- (adolescent- (13-18 years, N=218) onset had significantly higher rates for 4/7 unfavorable illness characteristics, including lifetime comorbid anxiety disorder, at least ten lifetime mood episodes, lifetime alcohol use disorder, and prior suicide attempt, than those with adult-onset (>18 years, N=174). Childhood- but not adolescent-onset BD patients also had significantly higher rates of first-degree relative with mood disorder, lifetime substance use disorder, and rapid cycling in the prior year. Patients with pooled childhood/adolescent - compared to adult-onset had significantly higher rates for 5/7 of these unfavorable illness characteristics, while patients with childhood- compared to adolescent-onset had significantly higher rates for 4/7 of these unfavorable illness characteristics. Caucasian, insured, suburban, low substance abuse, American specialty clinic-referred sample limits generalizability. Onset age is based on retrospective recall. Childhood- compared to adolescent-onset BD was more robustly related to unfavorable bipolar illness characteristics, so pooling these groups attenuated such relationships. Further study is warranted to determine the extent to which adolescent-onset BD represents an intermediate phenotype between childhood- and adult-onset BD. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Other people's accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-06-15

    The first report from the Washington Accelerator Conference concentrated on news from the particle physics centres. But the bulk of the Conference covered the use of accelerators in other fields, underlining this valuable spinoff from particle physics.

  8. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  9. The electron accelerator Ridgetron

    International Nuclear Information System (INIS)

    Hayashizaki, N.; Hattori, T.; Odera, M.; Fujisawa, T.

    1999-01-01

    Many electron accelerators of DC or RF type have been widely used for electron beam irradiation (curing, crosslinking of polymers, sterilization of medical disposables, preservation of food, etc.). Regardless of the acceleration energy, the accelerators to be installed in industrial facilities, have to satisfy the requires of compact size, low power consumption and stable operation. The DC accelerator is realized very compact in the energy under 300 keV, however, it is large to prevent the discharge of an acceleration column in the energy over 300 keV. The RF electron accelerator Ridgetron has been developed to accelerate the continuous beam of the 0.5-10 MeV range in compact space. It is the first example as an electron accelerator incorporated a ridged RF cavity. A prototype system of final energy of 2.5 MeV has been studied to confirm the feasibility at present

  10. High brightness electron accelerator

    International Nuclear Information System (INIS)

    Sheffield, R.L.; Carlsten, B.E.; Young, L.M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of accelerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electrons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electrons as the electrons enter the first cavity. 5 figs

  11. Unified accelerator libraries

    International Nuclear Information System (INIS)

    Malitsky, Nikolay; Talman, Richard

    1997-01-01

    A 'Universal Accelerator Libraries' (UAL) environment is described. Its purpose is to facilitate program modularity and inter-program and inter-process communication among heterogeneous programs. The goal ultimately is to facilitate model-based control of accelerators

  12. YEREVAN: Acceleration workshop

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Sponsored by the Yerevan Physics Institute in Armenia, a Workshop on New Methods of Charged Particle Acceleration in October near the Nor Amberd Cosmic Ray Station attracted participants from most major accelerator centres in the USSR and further afield

  13. San Francisco Accelerator Conference

    International Nuclear Information System (INIS)

    Southworth, Brian

    1991-01-01

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  14. Large tandem accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1976-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of tandem accelerators designed to operate at maximum terminal potentials in the range 14 to 30 MV. In addition, a number of older tandem accelerators are now being significantly upgraded to improve their heavy ion performance. Both of these developments have reemphasized the importance of negative heavy ion sources. The new large tandem accelerators are described, and the requirements placed on negative heavy ion source technology by these and other tandem accelerators used for the acceleration of heavy ions are discussed. First, a brief description is given of the large tandem accelerators which have been completed recently, are under construction, or are funded for construction, second, the motivation for construction of these accelerators is discussed, and last, criteria for negative ion sources for use with these accelerators are presented

  15. Vp x B acceleration

    International Nuclear Information System (INIS)

    Sugihara, Ryo.

    1987-05-01

    A unique particle acceleration by an electrostatic (ES) wave, a magnetosonic shock wave as well as an electromagnetic (EM) wave is reviewed. The principle of the acceleration is that when a charged particle is carried across an external magnetic field the charge feels a DC field (the Lorentz force) and is accelerated. The theory for the ES wave acceleration is experimentally verified thought it is semi-quantitative. The shock acceleration is extensively studied theoretically and in a particle simulation method and the application is extended to phenomena in interplanetary space. The EM wave acceleration is based on a trapping in a moving neutral sheet created by the wave magnetic field and the external magnetic field, and the particle can be accelerated indefinitely. A brief sketch on a slow-wave-structure for this acceleration will be given. (author)

  16. Accelerator-timing system

    International Nuclear Information System (INIS)

    Timmer, E.; Heine, E.

    1985-01-01

    Along the NIKHEF accelerator in Amsterdam (Netherlands), at several places a signal is needed for the sychronisation of all devices with the acceleration process. In this report, basic principles and arrangements of this timing system are described

  17. Linear accelerator: A concept

    Science.gov (United States)

    Mutzberg, J.

    1972-01-01

    Design is proposed for inexpensive accelerometer which would work by applying pressure to fluid during acceleration. Pressure is used to move shuttle, and shuttle movement is sensed and calibrated to give acceleration readings.

  18. Diabetes and onset of natural menopause : Results from the European Prospective Investigation into Cancer and Nutrition

    NARCIS (Netherlands)

    Brand, J. S.; Onland-Moret, N. C.; Eijkemans, M. J C; Tjønneland, A.; Roswall, N.; Overvad, K.; Fagherazzi, G.; Clavel-Chapelon, F.; Dossus, L.; Lukanova, A.; Grote, V.; Bergmann, M. M.; Boeing, H.; Trichopoulou, A.; Tzivoglou, M.; Trichopoulos, D.; Grioni, S.; Mattiello, A.; Masala, G.; Tumino, R.; Vineis, P.; Bueno-De-Mesquita, H. B.; Weiderpass, E.; Redondo, M. L.; Sánchez, M. J.; Castaño, J. M Huerta; Arriola, L.; Ardanaz, E.; Duell, E. J.; Rolandsson, O.; Franks, P. W.; Butt, S.; Nilsson, P.; Khaw, K. T.; Wareham, N.; Travis, R.; Romieu, I.; Gunter, M. J.; Riboli, E.; Van Der Schouw, Y. T.

    2015-01-01

    STUDY QUESTION Do women who have diabetes before menopause have their menopause at an earlier age compared with women without diabetes? SUMMARY ANSWER Although there was no overall association between diabetes and age at menopause, our study suggests that early-onset diabetes may accelerate

  19. Heavy ion accelerators

    International Nuclear Information System (INIS)

    Schmelzer, C.

    1974-01-01

    This review of the present state of work on heavy-ion accelerators pays particular attention to the requirements for nuclear research. It is divided into the following sections: single-particle versus collective acceleration, heavy-ion accelerators, beam quality, and a status report on the UNILAC facility. Among the topics considered are the recycling cyclotron, linacs with superconducting resonators, and acceleration to the GeV/nucleon range. (8 figures, 2 tables) (U.S.)

  20. Accelerators at school

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required

  1. Accelerators at school

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-06-15

    Latest subject covered by the CERN Accelerator School was 'Applied Geodesy of Particle Accelerators', which attracted an impressive number of outside participants to CERN for a week in April. Since the forerunners of today's particle accelerators were demonstrated over 50 years ago, the positioning of accelerator components has progressed from the laboratory bench-top to tunnels tens of kilometres long. Despite this phenomenal growth in size, sub-millimetre accuracy is still required.

  2. Accelerators for Medicine

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    This lecture will review the different applications of particle accelerators to the medical field, from cancer treatment with beams of accelerator-produced particles (photons, electrons, protons, ions and neutrons) to the generation of radioactive isotopes used in medical diagnostics, in cancer therapy and in the new domain of theragnostics. For each application will be outlined the state of the art, the potential, and the accelerator challenges to be faced to meet the increasing demand for therapeutic procedures based on accelerators.

  3. Large electrostatic accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1984-01-01

    The paper is divided into four parts: a discussion of the motivation for the construction of large electrostatic accelerators, a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year

  4. Particle beam accelerator

    International Nuclear Information System (INIS)

    Turner, N.L.

    1982-01-01

    A particle beam accelerator is described which has several electrodes that are selectively short circuited together synchronously with changes in the magnitude of a DC voltage applied to the accelerator. By this method a substantially constant voltage gradient is maintained along the length of the unshortened electrodes despite variations in the energy applied to the beam by the accelerator. The invention has particular application to accelerating ion beams that are implanted into semiconductor wafers. (U.K.)

  5. Superconducting accelerator technology

    International Nuclear Information System (INIS)

    Grunder, H.A.; Hartline, B.K.

    1986-01-01

    Modern and future accelerators for high energy and nuclear physics rely increasingly on superconducting components to achieve the required magnetic fields and accelerating fields. This paper presents a practical overview of the phenomenon of superconductivity, and describes the design issues and solutions associated with superconducting magnets and superconducting rf acceleration structures. Further development and application of superconducting components promises increased accelerator performance at reduced electric power cost

  6. Applications of particle accelerators

    International Nuclear Information System (INIS)

    Barbalat, O.

    1994-01-01

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  7. [Juvenile-onset ankylosing spondylitis].

    Science.gov (United States)

    Menkes, C J; Job-Deslandre, C; Feldmann, J L

    1984-02-16

    Ankylosing spondylitis (AS) with juvenile onset (under 17 years of age) is not infrequent. Thirty-six cases were studied, amounting to 18% of patients hospitalized between 1977 and 1981. The following criteria were used for diagnosis: radiologic sacroiliitis (typical AS), presence of HLA B27 and/or pelvic or vertebral clinical manifestations (possible AS). 31 patients (85%) were boys. Mean age at onset was 12.3 +/- 2.8 years. In three cases, AS was found in a member of the family of the propositus and in one case there was cutaneous psoriasis. Usually (29 cases) onset was in the lower limbs: arthritis of the knee (14 cases), hip (9 cases), ankle (7 cases) or painful heel (4 cases). During the course (with a mean follow-up of 11.2 +/- 7 years), 35 patients exhibited peripheral joint diseases and 25 had axial involvement. Ocular involvement was present in 5 cases. 10 patients had a modification of respiratory function. Radiologic sacroiliitis was found in 31 patients but with a delay of 5.3 +/- 2.6 years. Vertebral radiologic lesions were only seen in 11 patients. Radiologic hip involvement was frequent (20 cases) with complete destruction in 6 patients. Erosion and ossification of the calcaneum were observed in 15 cases. The ESR was above 20 mm/first hour in 26 cases (72%). 81% of these patients were HLA B27 positive. Functional prognosis was good: 16 patients (51.6%) led an almost normal life, 6 were bedridden (Steinbrocker's grade IV), 3 had severe impairment (grade III) and 6 had slight impairment (grade II).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Performance of the FELIX accelerator

    International Nuclear Information System (INIS)

    Geer, C.A.J. van der; Bakker, R.J.; Meer, A.F.G. van der; Amersfoort, P.W. van; Gillespie, W.A.; Martin, P.F.

    1992-01-01

    The FELIX project (Free Electron Laser for Infrared eXperiments) involves the construction and operation of a rapidly tunable FEL users facility for the infrared based on a rf linear accelerator. Lasing was obtained in the summer of 1991. The spectral region already covered is between 16 and 110 μm to be extended to below 8 μm with an additional linac section. Measurement of several electron beam parameters along the beam line are presented. (author) 6 refs.; 7 figs

  9. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  10. Angular Acceleration without Torque?

    Science.gov (United States)

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  11. Accelerators and Dinosaurs

    CERN Multimedia

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  12. Far field acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  13. Early- versus Late-Onset Systemic Sclerosis

    Science.gov (United States)

    Alba, Marco A.; Velasco, César; Simeón, Carmen Pilar; Fonollosa, Vicent; Trapiella, Luis; Egurbide, María Victoria; Sáez, Luis; Castillo, María Jesús; Callejas, José Luis; Camps, María Teresa; Tolosa, Carles; Ríos, Juan José; Freire, Mayka; Vargas, José Antonio; Espinosa, Gerard

    2014-01-01

    Abstract Peak age at onset of systemic sclerosis (SSc) is between 20 and 50 years, although SSc is also described in both young and elderly patients. We conducted the present study to determine if age at disease onset modulates the clinical characteristics and outcome of SSc patients. The Spanish Scleroderma Study Group recruited 1037 patients with a mean follow-up of 5.2 ± 6.8 years. Based on the mean ± 1 standard deviation (SD) of age at disease onset (45 ± 15 yr) of the whole series, patients were classified into 3 groups: age ≤30 years (early onset), age between 31 and 59 years (standard onset), and age ≥60 years (late onset). We compared initial and cumulative manifestations, immunologic features, and death rates. The early-onset group included 195 patients; standard-onset group, 651; and late-onset, 191 patients. The early-onset group had a higher prevalence of esophageal involvement (72% in early-onset compared with 67% in standard-onset and 56% in late-onset; p = 0.004), and myositis (11%, 7.2%, and 2.9%, respectively; p = 0.009), but a lower prevalence of centromere antibodies (33%, 46%, and 47%, respectively; p = 0.007). In contrast, late-onset SSc was characterized by a lower prevalence of digital ulcers (54%, 41%, and 34%, respectively; p < 0.001) but higher rates of heart conduction system abnormalities (9%, 13%, and 21%, respectively; p = 0.004). Pulmonary hypertension was found in 25% of elderly patients and in 12% of the youngest patients (p = 0.010). After correction for the population effects of age and sex, standardized mortality ratio was shown to be higher in younger patients. The results of the present study confirm that age at disease onset is associated with differences in clinical presentation and outcome in SSc patients. PMID:24646463

  14. Virtual Accelerator for Accelerator Optics Improvement

    CERN Document Server

    Yan Yi Ton; Decker, Franz Josef; Ecklund, Stanley; Irwin, John; Seeman, John; Sullivan, Michael K; Turner, J L; Wienands, Ulrich

    2005-01-01

    Through determination of all quadrupole strengths and sextupole feed-downs by fitting quantities derivable from precision orbit measurement, one can establish a virtual accelerator that matches the real accelerator optics. These quantities (the phase advances, the Green's functions, and the coupling eigen-plane ellipses tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a model-independent analysis (MIA). Instead of trying to identify magnet errors, a limited number of quadrupoles are chosen for optimized strength adjustment to improve the virtual accelerator optics and then applied to the real accelerator accordingly. These processes have been successfully applied to PEP-II rings for beta beating fixes, phase and working tune adjustments, and linear coupling reduction to improve PEP-II luminosity.

  15. Criteria for onset of firestorms

    International Nuclear Information System (INIS)

    Carrier, G.F.; Fendell, F.E.; Feldman, P.S.

    1983-01-01

    Quantitative criteria are evolved for onset of firestorms, severe stationary (nonpropagating) holocausts arising via merger of fires from multiple simultaneous ignitions in a heavily fuel-laden urban environment. Within an hour, surface-level radial inflow from all directions sustains a large-diameter convective column that eventually reaches altitude of about 10 km (e.g., Hamburg, Dresden, Hiroshima). As the firestorm achieves peak intensity (2 to 3 hours after the ignitions), inflow speeds are inferred to attain 25 to 50 m/s; typically 12 km 2 are reduced to ashes, before winds relax to ambient levels in six-to-nine hours. Here the firestorm is interpreted to be a mesocyclone (rotating severe local storm). Even with exceedingly large heat release sustained over a concentrated area, in the presence of a very nearly autoconvectively unstable atmospheric stratification, onset of vigorous swirling on the scale of two hours requires more than concentration of circulation associated with the rotation of the earth; rather, a preexisting, if weak, circulation appears necessary for firestorm cyclogenesis

  16. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  17. Notes on Laser Acceleration

    International Nuclear Information System (INIS)

    Tajima, T.

    2008-01-01

    This note intends to motivate our effort toward the advent of new methods of particle acceleration, utilizing the fast rising laser technology. By illustrating the underlying principles in an intuitive manner and thus less jargon-clad fashion, we seek a direction in which we shall be able to properly control and harness the promise of laser acceleration. First we review the idea behind the laser wakefield. We then go on to examine ion acceleration by laser. We examine the sheath acceleration in particular and look for the future direction that allows orderly acceleration of ions in high energies

  18. CAS CERN Accelerator School: Superconductivity in particle accelerators. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Turner, S [ed.

    1996-05-01

    These proceedings present the lectures given at the ninth specialized course organized by the CERN Accelerator School (CAS), the topic this time being ``Superconductivity in Particle Accelerators``. This course is basically a repeat of that given at the same location in 1988 whose proceedings were published as CERN 89-04. However, the opportunity was taken to improve the presentation of the various topics and to introduce the latest developments in this rapidly expanding field. First the basic theory of superconductivity is introduced. A review of the materials used for sc magnetics is followed by magnet design requirements, the influence of eddy and persistent currents, and the methods used to provide quench protection. Next follows the basic theory of sc cavities, their materials, high-gradient limitations, the problem of field emission and then their power couplers. After an introduction to cryogenics and cryoplants, the theory of superfluidity is presented followed by a review of the use of superfluid helium. Finally, two seminars detail the impact of superconductors in the design of the LHC and LEP2 accelerators. (orig.).

  19. CAS CERN Accelerator School: Superconductivity in particle accelerators. Proceedings

    International Nuclear Information System (INIS)

    Turner, S.

    1996-05-01

    These proceedings present the lectures given at the ninth specialized course organized by the CERN Accelerator School (CAS), the topic this time being ''Superconductivity in Particle Accelerators''. This course is basically a repeat of that given at the same location in 1988 whose proceedings were published as CERN 89-04. However, the opportunity was taken to improve the presentation of the various topics and to introduce the latest developments in this rapidly expanding field. First the basic theory of superconductivity is introduced. A review of the materials used for sc magnetics is followed by magnet design requirements, the influence of eddy and persistent currents, and the methods used to provide quench protection. Next follows the basic theory of sc cavities, their materials, high-gradient limitations, the problem of field emission and then their power couplers. After an introduction to cryogenics and cryoplants, the theory of superfluidity is presented followed by a review of the use of superfluid helium. Finally, two seminars detail the impact of superconductors in the design of the LHC and LEP2 accelerators. (orig.)

  20. Industrial Application of Accelerators

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Univer...

  1. Industrial Application of Accelerators

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Uni...

  2. Accelerations in Flight

    Science.gov (United States)

    Doolittle, J H

    1925-01-01

    This work on accelerometry was done at McCook Field for the purpose of continuing the work done by other investigators and obtaining the accelerations which occur when a high-speed pursuit airplane is subjected to the more common maneuvers. The accelerations obtained in suddenly pulling out of a dive with well-balanced elevators are shown to be within 3 or 4 per cent of the theoretically possible accelerations. The maximum acceleration which a pilot can withstand depends upon the length of time the acceleration is continued. It is shown that he experiences no difficulty under the instantaneous accelerations as high as 7.8 G., but when under accelerations in excess of 4.5 G., continued for several seconds, he quickly loses his faculties.

  3. Accelerators for energy

    International Nuclear Information System (INIS)

    Inoue, Makoto

    2000-01-01

    A particle accelerator is a device to consume energy but not to produce it. Then, the titled accelerator seems to mean an accelerator for using devices related to nuclear energy. For an accelerator combined to nuclear fissionable fuel, neutron sources are D-T type, (gamma, n) reaction using electron beam type spallation type, and so forth. At viewpoints of powers of incident beam and formed neutron, a spallation type source using high energy proton is told to be effective but others have some advantages by investigation on easy operability, easy construction, combustion with target, energy and directivity of neutron, and so forth. Here were discussed on an accelerator for research on accelerator driven energy system by dividing its researching steps, and on kind, energy, beam intensity, and so forth of an accelerator suitable for it. And, space electric charge effect at beam propagation direction controlled by beam intensity of cyclotron was also commented. (G.K.)

  4. Experiments on heat pipes submitted to strong accelerations; Experimentation de caloducs soumis a de fortes accelerations

    Energy Technology Data Exchange (ETDEWEB)

    Labuthe, A [Dassault Aviation, 92 - Saint Cloud (France)

    1997-12-31

    In order to evaluate the possibility to use heat pipes as efficient heat transfer devices in aircrafts, a study of their behaviour during strong accelerations is necessary. This study has been jointly carried out by the Laboratory of Thermal Studies of Poitiers (France) and Dassault Aviation company. It is based on a series of tests performed with an experimental apparatus that uses the centrifugal effect to simulate the acceleration fields submitted to the heat pipe. Un-priming - priming cycles have been performed under different power and acceleration levels and at various functioning temperatures in order to explore the behaviour of heat pipes: rate of un-priming and re-priming, functioning in blocked mode etc.. This preliminary study demonstrates the rapid re-priming of the tested heat pipes when submitted to favourable acceleration situations and the possibility to use them under thermosyphon conditions despite the brief unfavourable acceleration periods encountered. (J.S.)

  5. Experiments on heat pipes submitted to strong accelerations; Experimentation de caloducs soumis a de fortes accelerations

    Energy Technology Data Exchange (ETDEWEB)

    Labuthe, A. [Dassault Aviation, 92 - Saint Cloud (France)

    1996-12-31

    In order to evaluate the possibility to use heat pipes as efficient heat transfer devices in aircrafts, a study of their behaviour during strong accelerations is necessary. This study has been jointly carried out by the Laboratory of Thermal Studies of Poitiers (France) and Dassault Aviation company. It is based on a series of tests performed with an experimental apparatus that uses the centrifugal effect to simulate the acceleration fields submitted to the heat pipe. Un-priming - priming cycles have been performed under different power and acceleration levels and at various functioning temperatures in order to explore the behaviour of heat pipes: rate of un-priming and re-priming, functioning in blocked mode etc.. This preliminary study demonstrates the rapid re-priming of the tested heat pipes when submitted to favourable acceleration situations and the possibility to use them under thermosyphon conditions despite the brief unfavourable acceleration periods encountered. (J.S.)

  6. The United States Particle Accelerator School: Educating the Next Generation of Accelerator Scientists and Engineers

    International Nuclear Information System (INIS)

    Barletta, William A.

    2009-01-01

    Only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) is National Graduate Educational Program that has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator/beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. The USPAS paradigm is readily extensible to other rapidly developing, cross-disciplinary research areas such as high energy density physics.

  7. The United States Particle Accelerator School: Educating the next generation of accelerator scientists and engineers

    International Nuclear Information System (INIS)

    Barletta, William A.

    2008-01-01

    Only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) is National Graduate Educational Program that has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator / beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. The USPAS paradigm is readily extensible to other rapidly developing, crossdisciplinary research areas such as high energy density physics

  8. Non-isochronous spiral orbit particle accelerator and fixed frequency closed orbit particle accelerator

    International Nuclear Information System (INIS)

    Fujisawa, Takashi; Hattori, Toshiyuki

    2006-01-01

    One of the present inventions provides a spiral orbit charged particle accelerator in which the magnetic field increases as the radius increases more rapidly than an isochronous magnetic field distribution, and the distribution of fixed-frequency accelerating RF voltage is formed so that a harmonic number changes in integer for every particle revolution. The other invention realizes to make the closed orbit charged particle accelerator having a fixed frequency amplitude modulator that is able to modulate amplitude of the RF voltage so that a harmonic number decreases in integer in an every particle revolution. (author)

  9. The Indian Summer Monsoon onset revisited: new approach based on the analysis of historical wind observations

    Science.gov (United States)

    Ordoñez, Paulina; Gallego, David; Ribera, Pedro; Peña-Ortiz, Cristina; Garcia-Herrera, Ricardo; Vega, Inmaculada; Gómez, Francisco de Paula

    2016-04-01

    The Indian Summer Monsoon onset is one of the meteorological events most anticipated in the world. Due to its relevance for the population, the India Meteorological Department has dated the onset over the southern tip of the Indian Peninsula (Kerala) since 1901. The traditional method to date the onset was based in the judgment of skilled meteorologist and because of this, the method was considered subjective and not adequate for the study of long-term changes in the onset. A new method for determining the monsoon onset based solely on objective criteria has been in use since 2006. Unfortunately, the new method relies -among other variables- on OLR measurements. This requirement impedes the construction of an objective onset series before the satellite era. An alternative approach to establish the onset by objective methods is the use of the wind field. During the last decade, some works have demonstrated that the changes in the wind direction in some areas of the Indian Ocean can be used to determine the monsoon onset rather precisely. However, this method requires precise wind observations over a large oceanic area which has limited the periods covered for such kind of indices to those of the reanalysis products. In this work we present a new approach to track the Indian monsoon onset based solely on historical wind direction measurements taken onboard ships. Our new series provides an objective record of the onset since the last decade of the 19th century and perhaps more importantly, it can incorporate any new historical wind record not yet known in order to extend the series length. The new series captures quite precisely the rapid precipitation increase associated to the monsoon onset, correlates well with previous approaches and it is robust against anomalous (bogus) onsets. Although no significant trends in the onset date were detected, a tendency to later than average onsets during the 1900-1925 and 1970-1990 periods and earlier than average onsets between

  10. Age at migration, family instability, and timing of sexual onset.

    Science.gov (United States)

    Goldberg, Rachel E; Tienda, Marta; Adserà, Alícia

    2017-03-01

    This study builds on and extends previous research on nativity variations in adolescent health and risk behavior by addressing three questions: (1) whether and how generational status and age at migration are associated with timing of sexual onset among U.S. adolescents; (2) whether and how family instability mediates associations between nativity and sexual debut; and (3) whether and how these associations vary by gender. We find that first- and second-generation immigrant youth initiate sexual activity later than native youth. Foreign-born youth who migrate after the start of adolescence exhibit the latest sexual onset; boys' sexual behavior is particularly sensitive to age at migration. Parental union stability is protective for first- and second-generation youth, especially boys; however, instability in co-residence with parents accelerates sexual debut for foreign-born girls, and dilutes protections from parental marital stability. Use of a non-English language at home delays sexual onset for immigrant girls, but not boys. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Onset of self-assembly

    International Nuclear Information System (INIS)

    Chitanvis, S.M.

    1998-01-01

    We have formulated a theory of self-assembly based on the notion of local gauge invariance at the mesoscale. Local gauge invariance at the mesoscale generates the required long-range entropic forces responsible for self-assembly in binary systems. Our theory was applied to study the onset of mesostructure formation above a critical temperature in estane, a diblock copolymer. We used diagrammatic methods to transcend the Gaussian approximation and obtain a correlation length ξ∼(c-c * ) -γ , where c * is the minimum concentration below which self-assembly is impossible, c is the current concentration, and γ was found numerically to be fairly close to 2/3. The renormalized diffusion constant vanishes as the critical concentration is approached, indicating the occurrence of critical slowing down, while the correlation function remains finite at the transition point. copyright 1998 The American Physical Society

  12. Particle-accelerator decommissioning

    International Nuclear Information System (INIS)

    Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.

    1979-12-01

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  13. An introduction to acceleration mechanisms

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1987-05-01

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration

  14. Spontaneous intraparenchymal otogenic pneumocephalus presenting with abrupt onset of coma

    International Nuclear Information System (INIS)

    Scuotto, A.; Cappabianca, S.; Capasso, R.; Natale, M.; D'Oria, S.; Rotondo, M.

    2016-01-01

    We report a case of spontaneous otogenic pneumocephalus, manifesting with a rapid deterioration of consciousness level. A 37-year-old man presented a 3-days history of headache and fluctuant confusion. On admission the patient was neurologically intact except for temporo-spatial disorientation. Brain Computed Tomography (CT) scan showed a large air collection in the left temporal lobe, causing mass effect. Hyperpneumatisation of mastoid air cells was also noticed. Because of the abrupt onset of coma (Glasgow Coma Scale = 10), emergency surgical evacuation of tensive pneumocephalus was carried out. Postoperatively, the patient quickly regained a good level of consciousness and was headache-free. - Highlights: • Spontaneous otogenic pneumocephalus generally presents with subtle symptoms. • Sudden consciousness involvement is a rare onset condition. • Hyperpneumatisation of the petrous bone is a predisposing factor.

  15. A rapidly enlarging cutaneous hemangioma in pregnancy.

    LENUS (Irish Health Repository)

    Ma'ayeh, Marwan

    2014-06-18

    This is a case of a rapidly enlarging cutaneous pedunculated tumor on a patient\\'s thumb during her pregnancy. This was excised and identified as a hemangioma. A literature search identified a possible hormonal factor in causing an accelerated growth of this tumor.

  16. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  17. 2014 Accelerators meeting, Grenoble

    International Nuclear Information System (INIS)

    Lucotte, Arnaud; Lamy, Thierry; De Conto, Jean-Marie; Fontaine, Alain; Revol, Jean-Luc; Nadolski, Laurent S.; Kazamias, Sophie; Vretenar, Maurizio; Ferrando, Philippe; Laune, Bernard; Vedrine, Pierre

    2014-10-01

    The Accelerators meeting is organised every two years by the Accelerators division of the French Society of Physics (SFP). It brings together about 50 participants during a one-day meeting. The morning sessions are devoted to scientific presentations while the afternoon is dedicated to technical visits of facilities. This document brings together the available presentations (slides): 1 - Presentation of the Laboratory of subatomic physics and cosmology - LPSC-Grenoble (Lucotte, Arnaud; Lamy, Thierry); 2 - Presentation of the Accelerators division of the French Society of Physics (Fontaine, Alain; Revol, Jean-Luc); 3 - Presentation of Grenoble's master diplomas in Accelerator physics (Nadolski, Laurent S.); 4 - Presentation of Paris' master diplomas in big instruments (Kazamias, Sophie); 5 - Particle accelerators and European Union's projects (Vretenar, Maurizio); 6 - French research infrastructures (Ferrando, Philippe); 7 - Coordination of accelerators activity in France (Laune, Bernard; Vedrine, Pierre)

  18. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L; Duru, Ph; Koch, J M; Revol, J L; Van Vaerenbergh, P; Volpe, A M; Clugnet, K; Dely, A; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  19. Accelerator reliability workshop

    International Nuclear Information System (INIS)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D.

    2002-01-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  20. Acceleration of radioactive ions

    International Nuclear Information System (INIS)

    Laxdal, R.E.

    2003-01-01

    There is an intense interest world-wide in the use of radioactive ion beams (RIBs) for experiment. In many existing or proposed facilities ions are produced or collected at source potential, ionized and re-accelerated. Within the past year three new ISOL based facilities have added dedicated post-accelerators to deliver accelerated RIBs to experiment. The paper gives an overview of RIB accelerators present and future, and explores the inherent features in the various acceleration methods with an emphasis on heavy ion linacs. The ISAC-I and ISAC-II post-accelerators are discussed as examples. Commissioning results and initial operating experience with ISAC-I will be presented

  1. Nuclear physics accelerator facilities

    International Nuclear Information System (INIS)

    1988-12-01

    This paper describes many of the nuclear physics heavy-ion accelerator facilities in the US and the research programs being conducted. The accelerators described are: Argonne National Laboratory--ATLAS; Brookhaven National Laboratory--Tandem/AGS Heavy Ion Facility; Brookhaven National Laboratory--Relativistic Heavy Ion Collider (RHIC) (Proposed); Continuous Electron Beam Accelerator Facility; Lawrence Berkeley Laboratory--Bevalac; Lawrence Berkeley Laboratory--88-Inch Cyclotron; Los Alamos National Laboratory--Clinton P. Anderson Meson Physics Facility (LAMPF); Massachusetts Institute of Technology--Bates Linear Accelerator Center; Oak Ridge National Laboratory--Holifield Heavy Ion Research Facility; Oak Ridge National Laboratory--Oak Ridge Electron Linear Accelerator; Stanford Linear Accelerator Center--Nuclear Physics Injector; Texas AandM University--Texas AandM Cyclotron; Triangle Universities Nuclear Laboratory (TUNL); University of Washington--Tandem/Superconducting Booster; and Yale University--Tandem Van de Graaff

  2. Accelerator shielding benchmark problems

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  3. Plasma particle accelerators

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1988-01-01

    The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs

  4. Wake field accelerators

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1986-02-01

    In a wake field accelerator a high current driving bunch injected into a structure or plasma produces intense induced fields, which are in turn used to accelerate a trailing charge or bunch. The basic concepts of wake field acceleration are described. Wake potentials for closed cavities and periodic structures are derived, as are wake potentials on a collinear path with a charge distribution. Cylindrically symmetric structures excited by a beam in the form of a ring are considered

  5. CONFERENCE: Computers and accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-01-15

    In September of last year a Conference on 'Computers in Accelerator Design and Operation' was held in West Berlin attracting some 160 specialists including many from outside Europe. It was a Europhysics Conference, organized by the Hahn-Meitner Institute with Roman Zelazny as Conference Chairman, postponed from an earlier intended venue in Warsaw. The aim was to bring together specialists in the fields of accelerator design, computer control and accelerator operation.

  6. CERN Accelerator School

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The CERN Accelerator School (CAS) recently held its Advanced Accelerator Physics course in Greece on the island of Rhodes. Complementing the general course in Finland last year, this course was organized together with the University of Athens and NCSR. Demokritos. Accelerator specialists from Europe, CIS, Japan and USA followed two weeks of ''state-of-theart'' lectures designed to complete their education in the field

  7. Factor analysis of symptom profile in early onset and late onset OCD.

    Science.gov (United States)

    Grover, Sandeep; Sarkar, Siddharth; Gupta, Gourav; Kate, Natasha; Ghosh, Abhishek; Chakrabarti, Subho; Avasthi, Ajit

    2018-04-01

    This study aimed to assess the factor structure of early and late onset OCD. Additionally, cluster analysis was conducted in the same sample to assess the applicability of the factors. 345 participants were assessed with Yale Brown Obsessive Compulsive Scale symptom checklist. Patients were classified as early onset (onset of symptoms at age ≤ 18 years) and late onset (onset at age > 18 years) OCD depending upon the age of onset of the symptoms. Factor analysis and cluster analysis of early-onset and late-onset OCD was conducted. The study sample comprised of 91 early onset and 245 late onset OCD subjects. Males were more common in the early onset group. Differences in the frequency of phenomenology related to contamination related, checking, repeating, counting and ordering/arranging compulsions were present across the early and late onset groups. Factor analysis of YBOCS revealed a 3 factor solution for both the groups, which largely concurred with each other. These factors were named as hoarding and symmetry (factor-1), contamination (factor-2) and aggressive, sexual and religious factor (factor-3). To conclude this study shows that factor structure of symptoms of OCD seems to be similar between early-onset and late-onset OCD. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Early- versus Late-Onset Dysthymia

    Science.gov (United States)

    Sansone, Lori A.

    2009-01-01

    In the current Diagnostic and Statistical Manual of Mental Disorders, dysthymic disorder is categorized as either early-onset or late-onset, based upon the emergence of symptoms before or after the age of 21, respectively. Does this diagnostic distinction have any meaningful clinical implications? In this edition of The Interface, we present empirical studies that have, within a single study, compared individuals with early-versus late-onset dysthymia. In this review, we found that, compared to those with late-onset dysthymia, early-onset patients are more likely to harbor psychiatric comorbidity both on Axis I and II, exhibit less psychological resilience, and have more prominent family loadings for mood disorders. These findings suggest that this distinction is meaningful and that the early-onset subtype of dysthymia is more difficult to effectively treat. PMID:20049145

  9. Applying the accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barbalat, Oscar

    1989-12-15

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology.

  10. Laser-driven accelerators

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Several devices for using laser fields have been proposed and they can be classified in three broad categories - 'far-field' accelerators (such as the principle of inverse free electron lasers), 'media' accelerators (which, for example, use the inverse Cherenkov effect or laser-controlled plasma waves), and 'near-field' accelerators (using a loaded guiding structure such as cavities or gratings). These different approaches come from the fact that a particle cannot be accelerated by the absorption of single photons (because of momentum conservation) and thus some other element has to intervene. (orig./HSI).

  11. Illinois Accelerator Research Center

    Science.gov (United States)

    Kroc, Thomas K.; Cooper, Charlie A.

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 Heavy Assembly Building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft2 Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, which contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. At IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.

  12. High Gradient Accelerator Research

    International Nuclear Information System (INIS)

    Temkin, Richard

    2016-01-01

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  13. Interacting with accelerators

    International Nuclear Information System (INIS)

    Dasgupta, S.

    1994-01-01

    Accelerators are research machines which produce energetic particle beam for use as projectiles to effect nuclear reactions. These machines along with their services and facilities may occupy very large areas. The man-machine interface of accelerators has evolved with technological changes in the computer industry and may be partitioned into three phases. The present paper traces the evolution of man-machine interface from the earliest accelerators to the present computerized systems incorporated in modern accelerators. It also discusses the advantages of incorporating expert system technology for assisting operators. (author). 8 ref

  14. Accelerator-based BNCT.

    Science.gov (United States)

    Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

    2014-06-01

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases. © 2013 Elsevier Ltd. All rights reserved.

  15. Applying the accelerator

    International Nuclear Information System (INIS)

    Barbalat, Oscar

    1989-01-01

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology

  16. Superconducting linear accelerator cryostat

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; Elkonin, B.V.; Sokolowski, J.S.

    1984-01-01

    A large vertical cryostat for a superconducting linear accelerator using quarter wave resonators has been developed. The essential technical details, operational experience and performance are described. (author)

  17. The appearance of microparticles in accelerator tubes

    International Nuclear Information System (INIS)

    Griffiths, G.L.; Eastham, D.A.; Kivlin, F.J.

    1978-07-01

    Microparticles have been found in submodules of accelerator tubes during the voltage conditioning process. The microparticle detector uses electrostatic induction and time-of-flight measurements to determine the charge and velocity of microparticles. Preliminary measurements with a charge sensitive limit of about 5 x 10 -15 C proves the presence of microparticles at a threshold voltage well below the onset of microdischarges or voltage breakdown. No direct evidence relating microparticles to the initiation of electrical breakdown has been found in this experiment. (author)

  18. Cosmic Accelerators: Engines of the Extreme Universe

    Energy Technology Data Exchange (ETDEWEB)

    Funk, Stefan

    2009-06-23

    The universe is home to numerous exotic and beautiful phenomena, some of which can generate almost inconceivable amounts of energy. While the night sky appears calm, it is populated by colossal explosions, jets from supermassive black holes, rapidly rotating neutron stars, and shock waves of gas moving at supersonic speeds. These accelerators in the sky boost particles to energies far beyond those we can produce on earth. New types of telescopes, including the Fermi Gamma-ray Space Telescope orbiting in space, are now discovering a host of new and more powerful accelerators. Please come and see how these observations are revising our picture of the most energetic phenomena in the universe.

  19. Late-Onset Inflammatory Response to Hyaluronic Acid Dermal Fillers

    Directory of Open Access Journals (Sweden)

    Tahera Bhojani-Lynch, MRCOphth, CertLRS, MBCAM, DipCS

    2017-12-01

    Conclusion:. Late-onset inflammatory reactions to HA fillers may be self-limiting but are easily and rapidly treatable with oral steroids, and with hyaluronidase in the case of lumps. It is likely these reactions are due to a Type IV delayed hypersensitivity response. Delayed inflammation associated with HA fillers is nonbrand specific. However, the case where 2 different brands were injected during the same session, but only 1 brand triggered a hypersensitivity reaction, suggests that the technology used in the manufacturing process, and the subsequent differing products of degradation, may have an influence on potential allergic reactions to HA fillers.

  20. Impact-induced acceleration by obstacles

    Science.gov (United States)

    Corbin, N. A.; Hanna, J. A.; Royston, W. R.; Singh, H.; Warner, R. B.

    2018-05-01

    We explore a surprising phenomenon in which an obstruction accelerates, rather than decelerates, a moving flexible object. It has been claimed that the right kind of discrete chain falling onto a table falls faster than a free-falling body. We confirm and quantify this effect, reveal its complicated dependence on angle of incidence, and identify multiple operative mechanisms. Prior theories for direct impact onto flat surfaces, which involve a single constitutive parameter, match our data well if we account for a characteristic delay length that must impinge before the onset of excess acceleration. Our measurements provide a robust determination of this parameter. This supports the possibility of modeling such discrete structures as continuous bodies with a complicated constitutive law of impact that includes angle of incidence as an input.

  1. Neonatal intracranial hemorrhages (perinatal onset)

    International Nuclear Information System (INIS)

    Ban, Sadahiko; Ogata, Masahiro; Yamamoto, Toyoshiro; Nakao, Satoshi; Mizue, Hidenari; Kobayashi, Yutaka.

    1982-01-01

    1. We have reviewed 34 cases of neonatal intracranial hemorrhages (perinatal onset, 23 mature and 11 premature infants) experienced in 10-year period from 1971 to 1980, with special reference to gestational age, birth weight, type of delivery, presence or absence of asphyxia, symptoms and cause of death. 2. Regarding 9 autopsied cases and 7 cases diagnosed by CT-scan, 10 mature infants composed of 3 subarachnoid hemorrhages, 2 intraventricular hemorrhages, 2 subdural hematomas, 2 intracerebral and 1 subependymal hemorrhage; 6 premature infants consisted of 4 subependymal hemorrhages with ventricular rupture and 2 subarachnoid hemorrhages. Most of them presented with respiratory distress, vomiting and convulsive seizures which developed within 5 days after birth. 3. Poor outcome including death amounted 49% of mature and 63% of premature infants. Along with degree of intracranial hematoma, prematurity and pulmonary complication were felt to be important prognostic factors. 4. Introduction of CT-scan led to prompt diagnosis and treatment, thus lowering mortality rate of neonatal intracranial hemorrhages. (author)

  2. [Neuroendocrine mechanisms of puberty onset].

    Science.gov (United States)

    Teinturier, C

    2002-10-01

    An increase in pulsatile release of GnRH is essential for the onset of puberty. However, the mechanism controlling the pubertal increase in GnRH release is still unclear. The GnRH neurosecretory system is already active during the neonatal period but subsequently enters a dormant state by central inhibition in the juvenile period. When this central inhibition is removed or diminished, an increase in GnRH release occurs with increase in synthesis and release of gonadotropins and gonadal steroids, followed by the appearance of secondary sexual characteristics. Recent studies suggest that disinhibition of GnRH neurons from GABA (gamma-aminobutyric acid) appears to be a critical factor in female rhesus monkey. After central inhibition is removed, increases in stimulatory input from glutamatergic neurons as well as new stimulatory input from norepinephrine and NPY neurons and inhibitory input from beta endorphin neurons appear to control pulsatile GnRH release as well as gonadal steroids. Nonetheless, the most important question still remains: what determines the timing to remove central inhibition? Because many genes are turned on or turned off to establish a complex series of events occurring during puberty, the timing of puberty must be regulated by a master gene or genes, as a part of developmental events.

  3. Accelerator Modeling with MATLAB Accelerator Toolbox

    International Nuclear Information System (INIS)

    2002-01-01

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model storage rings and beam transport lines in the MATLAB environment. The objective is to illustrate the flexibility and efficiency of the AT-MATLAB framework. The paper discusses three examples of problems that are analyzed frequently in connection with ring-based synchrotron light sources

  4. Santa Fe Accelerator Conference

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The 10th USA National Particle Accelerator Conference was hosted this year by the Los Alamos National Laboratory in Santa Fe from 21-23 March. It was a resounding success in emphasizing the ferment of activity in the accelerator field. About 900 people registered and about 500 papers were presented in invited and contributed talks and poster sessions

  5. Relativistic Shock Acceleration

    International Nuclear Information System (INIS)

    Duffy, P.; Downes, T.P.; Gallant, Y.A.; Kirk, J.G.

    1999-01-01

    In this paper we briefly review the basic theory of shock waves in relativistic hydrodynamics and magneto-hydrodynamics, emphasising some astrophysically interesting cases. We then present an overview of the theory of particle acceleration at such shocks describing the methods used to calculate the spectral indices of energetic particles. Recent results on acceleration at ultra-relativistic shocks are discussed. (author)

  6. CERN Accelerator School

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-01-15

    The CERN Accelerator School (CAS) offers a regular course on general accelerator physics. The first basic course was given in September 1984 at Orsay, France, and last September the advanced course was jointly organized by CAS, Oxford's Nuclear Physics Laboratory and the Rutherford Appleton Laboratory, and held at The Queen's College, Oxford.

  7. Accelerator for nuclear transmutation

    International Nuclear Information System (INIS)

    Schapira, J.P.

    1984-01-01

    A review on nuclear transmutation of radioactive wastes using particle accelerators is given. Technical feasibility, nuclear data, costs of various projects are discussed. It appears that one high energy accelerator (1500 MeV, 300 mA proton) could probably handle the amount of actinides generated by the actual French nuclear program [fr

  8. Diagnostics for induction accelerators

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960's to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore's Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail

  9. Diagnostics for induction accelerators

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1997-01-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at Lawrence Livermore National Laboratory (LLNL) from the early 1960s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400-ns pulses. The Advanced Test Accelerator (ATA) built at Livermore close-quote s Site 300 produced 10,000-Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and Lawrence Berkeley National Laboratory (LBNL). This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high-current, short-pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail. copyright 1997 American Institute of Physics

  10. Hamburg Accelerator Conference (2)

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Edmund J.N. [CERN Accelerator School (Switzerland)

    1992-11-15

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). The HEACC Conference traditionally reviews the status of all major accelerator projects whether they are already running like clockwork, still in the construction phase, or waiting impatiently for financial approval.

  11. Charged particle accelerator

    International Nuclear Information System (INIS)

    Arakawa, Kazuo.

    1969-01-01

    An accelerator is disclosed having a device which permits the electrodes of an accelerator tube to be readily conditioned in an uncomplicated manner before commencing operation. In particle accelerators, it is necessary to condition the accelerator electrodes before a stable high voltage can be applied. Large current accelerators of the cockcroft-walton type require a complicated manual operation which entails applying to the electrodes a low voltage which is gradually increased to induce a vacuum discharge and then terminated. When the discharge attains an extremely low level, the voltage is again impressed and again raised to a high value in low current type accelerators, a high voltage power supply charges the electrodes once to induce discharge followed by reapplying the voltage when the vacuum discharge reaches a low level, according to which high voltage is automatically applied. This procedure, however, requires that the high voltage power supply be provided with a large internal resistance to limit the current to within several milliamps. The present invention connects a high voltage power supply and an accelerator tube through a discharge current limiting resistor wired in parallel with a switch. Initially, the switch is opened enabling the power supply to impress a voltage limited to a prescribed value by a suitably chosen resistor. Conditioning is effected by allowing the voltage between electrodes to increase and is followed by closing the switch through which high voltage is applied directly to the accelerator for operation. (K.J. Owens)

  12. Asia honours accelerator physicists

    CERN Multimedia

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  13. Accelerators Beyond The Tevatron?

    Energy Technology Data Exchange (ETDEWEB)

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  14. CERN Accelerator School

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The CERN Accelerator School (CAS) offers a regular course on general accelerator physics. The first basic course was given in September 1984 at Orsay, France, and last September the advanced course was jointly organized by CAS, Oxford's Nuclear Physics Laboratory and the Rutherford Appleton Laboratory, and held at The Queen's College, Oxford

  15. Thoughts on accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1978-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  16. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  17. Racetrack linear accelerators

    International Nuclear Information System (INIS)

    Rowe, C.H.; Wilton, M.S. de.

    1979-01-01

    An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)

  18. Linear Accelerator (LINAC)

    Science.gov (United States)

    ... uses microwave technology (similar to that used for radar) to accelerate electrons in a part of the accelerator called the "wave guide," then allows ... risk of accidental exposure is extremely low. top of page This page was ... No Please type your comment or suggestion into the following text ...

  19. Hamburg Accelerator Conference (2)

    International Nuclear Information System (INIS)

    Wilson, Edmund J.N.

    1992-01-01

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). The HEACC Conference traditionally reviews the status of all major accelerator projects whether they are already running like clockwork, still in the construction phase, or waiting impatiently for financial approval

  20. Optimization of accelerator control

    International Nuclear Information System (INIS)

    Vasiljev, N.D.; Mozin, I.V.; Shelekhov, V.A.; Efremov, D.V.

    1992-01-01

    Expensive exploitation of charged particle accelerators is inevitably concerned with requirements of effectively obtaining of the best characteristics of accelerated beams for physical experiments. One of these characteristics is intensity. Increase of intensity is hindered by a number of effects, concerned with the influence of the volume charge field on a particle motion dynamics in accelerator's chamber. However, ultimate intensity, determined by a volume charge, is almost not achieved for the most of the operating accelerators. This fact is caused by losses of particles during injection, at the initial stage of acceleration and during extraction. These losses are caused by deviations the optimal from real characteristics of the accelerating and magnetic system. This is due to a number of circumstances, including technological tolerances on structural elements of systems, influence of measuring and auxiliary equipment and beam consumers' installations, placed in the closed proximity to magnets, and instability in operation of technological systems of accelerator. Control task consists in compensation of deviations of characteristics of magnetic and electric fields by optimal selection of control actions. As for technical means, automatization of modern accelerators allows to solve optimal control problems in real time. Therefore, the report is devoted to optimal control methods and experimental results. (J.P.N.)

  1. Accelerator breeder concept

    International Nuclear Information System (INIS)

    Bartholomew, G.A.; Fraser, J.S.; Garvey, P.M.

    1978-10-01

    The principal components and functions of an accelerator breeder are described. The role of the accelerator breeder as a possible long-term fissile production support facility for CANDU (Canada Deuterium Uranium) thorium advanced fuel cycles and the Canadian research and development program leading to such a facility are outlined. (author)

  2. Semiconductor acceleration sensor

    Science.gov (United States)

    Ueyanagi, Katsumichi; Kobayashi, Mitsuo; Goto, Tomoaki

    1996-09-01

    This paper reports a practical semiconductor acceleration sensor especially suited for automotive air bag systems. The acceleration sensor includes four beams arranged in a swastika structure. Two piezoresistors are formed on each beam. These eight piezoresistors constitute a Wheatstone bridge. The swastika structure of the sensing elements, an upper glass plate and a lower glass plate exhibit the squeeze film effect which enhances air dumping, by which the constituent silicon is prevented from breakdown. The present acceleration sensor has the following features. The acceleration force component perpendicular to the sensing direction can be cancelled. The cross-axis sensitivity is less than 3 percent. And, the erroneous offset caused by the differences between the thermal expansion coefficients of the constituent materials can be canceled. The high aspect ratio configuration realized by plasma etching facilitates reducing the dimensions and improving the sensitivity of the acceleration sensor. The present acceleration sensor is 3.9 mm by 3.9 mm in area and 1.2 mm in thickness. The present acceleration sensor can measure from -50 to +50 G with sensitivity of 0.275 mV/G and with non-linearity of less than 1 percent. The acceleration sensor withstands shock of 3000 G.

  3. Molecular ion acceleration using tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yuichi; Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-12-01

    In TIARA compound beam radiation system, cluster beams have been produced using 3 MV tandem accelerator (9SDH-2) to supply them to various radiation on injection experiments. Till now, productions of C{sub 2-8}, Si{sub 2-4} and O{sub 2} and their accelerations up to 6 MeV have been succeeded. This study aimed at production and acceleration of B{sub 2-4} and LiF. Anion clusters were produced using the conventional ion source of cesium sputter type. The proportions of atoms, molecules and clusters elicited from the ion source were varied depending on the material`s properties and the operating conditions of ion source such as sample temperature, sputter voltage and the shape of sample. The anion clusters were accelerated toward the high voltage terminal in the center of tandem accelerator, leading to cations through losing their electrons by the collision to N{sub 2} gas in a charge conversion cell at the terminal. Positively charged cluster ions could be obtained by modulating the pressure of N{sub 2} gas. Thus, B{sub 2} (64 nA), B{sub 3} (4.4 nA) and B{sub 4} (2.7 nA) have been produced and their maximum survival probabilities were higher than those of carbon or silicon clusters. In addition, the relationship between beam current and gas pressure was investigated for Bn (n = 2-4) and LiF. (M.N.)

  4. Understanding Tobacco Use Onset Among African Americans.

    Science.gov (United States)

    Roberts, Megan E; Colby, Suzanne M; Lu, Bo; Ferketich, Amy K

    2016-04-01

    Compared to the majority of non-Hispanic white ("white") cigarette smokers, many African American smokers demonstrate a later age of initiation. The goal of the present study was to examine African American late-onset smoking (ie, regular smoking beginning at age 18 or later) and determine whether late-onset (vs. early-onset) smoking is protective in terms of quit rates and health outcomes. We used data from the National Survey of Midlife Development in the United States (MIDUS) because the wide age range of participants (20-75 at baseline) allowed the examination of smoking cessation and mortality incidence across the lifespan. Consistent with previous research, results indicated a later average age of smoking onset among African Americans, compared to whites. Disentangling effects of race from age-of-onset, we found that the cessation rate among late-onset African American smokers was 33%, whereas rates for early-onset African American smokers and early- and late-onset white smokers ranged from 52% to 57%. Finally, results showed that among white, low-socioeconomic status (SES) smokers, the hazard rate for mortality was greater among early- versus late-onset smokers; in contrast, among African American smokers (both low- and high-SES) hazard rates for mortality did not significantly differ among early- versus late-onset smokers. Although late (vs. early) smoking onset may be protective for whites, the present results suggest that late-onset may not be similarly protective for African Americans. Tobacco programs and regulatory policies focused on prevention should expand their perspective to include later ages of initiation, in order to avoid widening tobacco-related health disparities. This study indicates that late-onset smoking is not only the norm among African American adult smokers, but that late- versus early-onset smoking (ie, delaying onset) does not appear to afford any benefits for African Americans in terms of cessation or mortality. These results

  5. Rapid shallow breathing

    Science.gov (United States)

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the ...

  6. TIARA electrostatic accelerator facility

    International Nuclear Information System (INIS)

    Tajima, Satoshi; Takada, Isao; Mizuhashi, Kiyoshi; Uno, Sadanori; Ohkoshi, Kiyonori; Nakajima, Yoshinori; Saitoh, Yuichi; Ishii, Yasuyuki; Kamiya, Tomihiro

    1996-07-01

    In order to promote the Advanced Radiation Technology Project, Japan Atomic Energy Research Institute constructed TIARA facility composed of four ion accelerators at Takasaki Radiation Chemistry Research Establishment for the period from 1988 to 1993. A 3MV tandem accelerator and an AVF cycrotron were completed in 1991 as the first phase of the construction, and a 3MV single-ended accelerator and a 400kV ion implanter were completed in 1993 as the second phase. Three electrostatic accelerators, the tandem, the single-ended and the implanter, were installed in the Multiple-beam facility of TIARA and have been operated for various experiments with using single, dual and triple beams without any serious trouble. This report describes the constructive works, machine performances, control systems, safety systems and accessory equipments of the electrostatic accelerators. (author)

  7. 2016 Accelerators meeting

    International Nuclear Information System (INIS)

    Spiro, Michel; Revol, Jean-Luc; Biarrotte, Jean-Luc; Napoly, Olivier; Jardin, Pascal; Chautard, Frederic; Thomas, Jean Charles; Petit, Eric

    2016-09-01

    The Accelerators meeting is organised every two years by the Accelerators division of the French Society of Physics (SFP). It brings together about 50 participants during a one-day meeting. The morning sessions are devoted to scientific presentations while the afternoon is dedicated to technical visits of facilities. This document brings together the available presentations (slides): 1 - Presentation of the Ganil - Grand accelerateur national d'ions lourds/Big national heavy-ion accelerator, Caen (Jardin, Pascal); 2 - Presentation of the Accelerators division of the French Society of Physics (Revol, Jean-Luc); 3 - Forward-looking and Prospective view (Napoly, Olivier); 4 - Accelerators at the National Institute of Nuclear and particle physics, situation, Forward-looking and Prospective view (Biarrotte, Jean-Luc); 5 - GANIL-SPIRAL2, missions and goals (Thomas, Jean Charles); 6 - The SPIRAL2 project (Petit, Eric)

  8. Collinear wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Chen, P.; Wilson, P.B.

    1985-04-01

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  9. Standing wave accelerating structures

    International Nuclear Information System (INIS)

    Zavadtsev, A.A.; Zverev, B.V.; Sobepin, N.P.

    1984-01-01

    Accelerating ELA structures are considered and chosen for applied purposes of special designation. Accelerating structures with the standing wave are considered most effective for small size ELA. Designs and results of experimental investigation of two new accelerating structures are described. These are structures of the ''ring'' type with a decreased number of excitinq oscillation types and strucuture with transverse rods with a twice smaller transverse size as compared with the biperiodical structure with internal connection resonators. The accelerating biperiodical structures of the conventional type by the fact that the whole structure is not a linear chain of connected resonators, but a ring one. Model tests have shown that the homogeneous structure with transverse rods (STR) at the frequency of 2.8 GHz in the regime of the standing wave has an effective shunt resistance equalling 23 MOhm/m. It is shown that the small transverse size of biperiodic STR makes its application in logging linear electron accelerators

  10. The Rapid Perceptual Impact of Emotional Distractors.

    Directory of Open Access Journals (Sweden)

    Briana L Kennedy

    Full Text Available The brief presentation of an emotional distractor can temporarily impair perception of a subsequent, rapidly presented target, an effect known as emotion-induced blindness (EIB. How rapidly does this impairment unfold? To probe this question, we examined EIB for targets that immediately succeeded ("lag-1" emotional distractors in a rapid stream of items relative to EIB for targets at later serial positions. Experiments 1 and 2 suggested that emotional distractors interfere with items presented very soon after them, with impaired target perception emerging as early as lag-1. Experiment 3 included an exploratory examination of individual differences, which suggested that EIB onsets more rapidly among participants scoring high in measures linked to negative affect.

  11. Accelerated irradiation growth of zirconium alloys

    International Nuclear Information System (INIS)

    Griffiths, M.; Gilbert, R.W.; Fidleris, V.

    1989-01-01

    This paper discusses how sponge zirconium and Zr-2.5 wt% Nb, Zircaloy, or Excel alloys all exhibit accelerated irradiation growth compared with high-purity crystal-bar zirconium for irradiation temperatures between 550 to 710 K and fluences between 0.1 to 10 x 10 25 n · m -2 (E > 1 MeV). There is generally an incubation period or fluence before the onset of accelerated or breakaway growth, which is dependent on the particular material being irradiated, its metallurgical condition before irradiation, and the irradiation temperature. Transmission electron microscopy has shown that there is a correlation between accelerated irradiation growth and the appearance of c-component vacancy loops on basal planes. Measurements in some specimens indicate that a significant fraction of the strain can be directly attributed to the loops themselves. There is considerable evidence to show that their formation is dependent both on the specimen purity and on the irradiation temperature. Materials that have a high interstitial-solute content contain c-component loops and exhibit high growth rates even at low fluences ( 2 :5 n · m -2 , E > 1 MeV). For sponge zirconium and the Zircaloys, c-component loop formation and the associated acceleration of growth (breakaway) during irradiation occurs because the intrinsic interstitial solute (mainly, oxygen, carbon and nitrogen) in the zirconium matrix is supplemented by interstitial iron, chromium, and nickel from the radiation-induced dissolution of precipitates. (author)

  12. Estrogen and early-onset Alzheimer's disease

    NARCIS (Netherlands)

    A.J.C. Slooter (Arjen); J.B. Bronzova (Juliana); A. Hofman (Albert); C. van Broeckhoven (Christine); C.M. van Duijn (Cornelia); J.C.M. Witteman (Jacqueline)

    1999-01-01

    textabstractEstrogen use may be protective for Alzheimer's disease with late onset. However, the effects on early onset Alzheimer's disease are unclear. This issue was studied in a population based setting. For each female patient, a female control was matched on age (within 5 years) and place of

  13. Spontaneous onset of Complex Regional Pain Syndrome

    NARCIS (Netherlands)

    de Rooij, A.M.; Perez, R.S.G.M.; Huygen, F.J.; van Eijs, F.; van Kleef, M.; Bauer, M.C.R.; van Hilten, J.J.; Marinus, J.

    2010-01-01

    Complex Regional Pain Syndrome (CRPS) usually develops after a noxious event, but spontaneous onsets have been described in 3-11% of the cases. The existence of spontaneous-onset CRPS is highly debated and the aim of the present study was therefore to compare the phenotypic characteristics of CRPS

  14. Substorm onset location and dipole tilt angle

    Directory of Open Access Journals (Sweden)

    J. Wanliss

    2006-03-01

    Full Text Available From an initial data set of over 200 substorms we have studied a subset of 30 magnetospheric substorms close to magnetic midnight to investigate, in a statistical fashion, the source region of the auroral arc that brightens at the onset of expansive phase. This arc is usually identified as the ionospheric signature of the expansive phase onset that occurs in the magnetotail. All the substorm onsets were identified via ground-based magnetometer and photometer data from the CANOPUS array. Various Tsyganenko global magnetic field models were used to map magnetic field lines from the location of the onset arc out to its greatest radial distance in the magnetotail. The results appear to favour the current disruption model of substorms since the average onset location has an average of 14.1 Earth radii (RE and is therefore more consistent with theories that place the onset location in the inner magnetotail. For the narrow range of tilts available our modeling indicates the parameter that appears to strongly influence the location of the substorm onset is the dipole tilt angle; as tilt becomes less negative onsets occur further downtail.

  15. Analyzing radial acceleration with a smartphone acceleration sensor

    Science.gov (United States)

    Vogt, Patrik; Kuhn, Jochen

    2013-03-01

    This paper continues the sequence of experiments using the acceleration sensor of smartphones (for description of the function and the use of the acceleration sensor, see Ref. 1) within this column, in this case for analyzing the radial acceleration.

  16. Collective ion acceleration

    International Nuclear Information System (INIS)

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  17. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  18. The miniature accelerator

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...

  19. Large electrostatic accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  20. Large electrostatic accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators

  1. Superconductivity and future accelerators

    International Nuclear Information System (INIS)

    Danby, G.T.; Jackson, J.W.

    1963-01-01

    For 50 years particle accelerators employing accelerating cavities and deflecting magnets have been developed at a prodigious rate. New accelerator concepts and hardware ensembles have yielded great improvements in performance and GeV/$. The great idea for collective acceleration resulting from intense auxiliary charged-particle beams or laser light may or may not be just around the corner. In its absence, superconductivity (SC) applied both to rf cavities and to magnets opened up the potential for very large accelerators without excessive energy consumption and with other economies, even with the cw operation desirable for colliding beams. HEP has aggressively pioneered this new technology: the Fermilab single ring 1 TeV accelerator - 2 TeV collider is near the testing stage. Brookhaven National Laboratory's high luminosity pp 2 ring 800 GeV CBA collider is well into construction. Other types of superconducting projects are in the planning stage with much background R and D accomplished. The next generation of hadron colliders under discussion involves perhaps a 20 TeV ring (or rings) with 40 TeV CM energy. This is a very large machine: even if the highest practical field B approx. 10T is used, the radius is 10x that of the Fermilab accelerator. An extreme effort to get maximum GeV/$ may be crucial even for serious consideration of funding

  2. Accelerator programme at CAT

    International Nuclear Information System (INIS)

    Ramamurthi, S.S.

    1991-01-01

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  3. Accelerator technical design report for high-intensity proton accelerator facility project, J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    This report presents the detail of the technical design of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. The accelerator complex comprises a 400-MeV room-temperature linac (600-MeV superconducting linac), 3-GeV rapid-cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The 400-MeV beam is injected to the RCS, being accelerated to 3 GEV. The 1-MW beam thus produced is guided to the Materials Life Science Experimental Facility, with both the pulsed spallation neutron source and muon source. A part of the beam is transported to the MR, which provides the 0.75-MW beam to either the Nuclear and Fundamental Particle Experimental Facility or the Neutrino Production Target. On the other hand, the beam accelerated to 600 MeV by the superconducting linac is used for the Nuclear Waster Transmutation Experiment. In this way, this facility is unique, being multipurpose one, including many new inventions and Research and Development Results. This report is based upon the accomplishments made by the Accelerator Group and others of the Project Team, which is organized on the basis of the Agreement between JAERI and KEK on the Construction and Research and Development of the High-Intensity Proton Accelerator Facility. (author)

  4. New accelerator ideas

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    In the past, providing higher particle beam energies meant building bigger accelerators. It is now universally accepted that with the current generation of accelerator projects either under construction (such as LEP at CERN) or proposed (such as the Superconducting Super Collider in the US), conventional techniques are reaching their practical limit. With the growing awareness that progress in particle physics requires new methods to accelerate particles, workshops and study groups are being set up across the world to search for ideas for the machines of tomorrow

  5. The auroral electron accelerator

    International Nuclear Information System (INIS)

    Bryant, D.A.; Hall, D.S.

    1989-01-01

    A model of the auroral electron acceleration process is presented in which the electrons are accelerated resonantly by lower-hybrid waves. The essentially stochastic acceleration process is approximated for the purposes of computation by a deterministic model involving an empirically derived energy transfer function. The empirical function, which is consistent with all that is known of electron energization by lower-hybrid waves, allows many, possibly all, observed features of the electron distribution to be reproduced. It is suggested that the process occurs widely in both space and laboratory plasmas. (author)

  6. ACCELERATORS: School report

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-12-15

    The expanded 1987 US Particle Accelerator School, held at Fermilab from 20 July to 14 August, included two two-week sessions. In the first, 101 students covered three university-style courses, listed as upper-division University of Chicago physics, covering the fundamentals of particle beams, magnetic optics and acceleration; relativistic electronics; and high energy storage rings. The 180 participants in the second session profited from 24 short courses presented by experts and covering a wide variety of topics in the physics and technology of particle accelerators.

  7. Hadron accelerators in medicine

    International Nuclear Information System (INIS)

    Amaldi, U.

    1996-01-01

    The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadron-therapy Project is then described in some detail, with reference ro both the National Centre for Oncological Hadron-therapy and the design of different types of compact proton accelerators aimed at introducing proton therapy in a large umber of hospitals. (author)

  8. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  9. ACCELERATORS: School prizes

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Dedicated to its goal of encouraging scientists and students to work in the field of particle accelerators, the US Particle Accelerator School (operating since 1981) has switched to a new format. Starting this year, it will offer in alternate years basic accelerator physics plus advanced subjects in both university and symposium styles over four weeks. Expanding the school from two to four weeks gives additional flexibility, and undergraduate participation should be encouraged by university credits being offered for particular courses. In the intervening years, the school will organize six-day topical courses

  10. Accelerator Toolbox for MATLAB

    International Nuclear Information System (INIS)

    Terebilo, Andrei

    2001-01-01

    This paper introduces Accelerator Toolbox (AT)--a collection of tools to model particle accelerators and beam transport lines in the MATLAB environment. At SSRL, it has become the modeling code of choice for the ongoing design and future operation of the SPEAR 3 synchrotron light source. AT was designed to take advantage of power and simplicity of MATLAB--commercially developed environment for technical computing and visualization. Many examples in this paper illustrate the advantages of the AT approach and contrast it with existing accelerator code frameworks

  11. RF linear accelerators

    CERN Document Server

    Wangler, Thomas P

    2008-01-01

    Thomas P. Wangler received his B.S. degree in physics from Michigan State University, and his Ph.D. degree in physics and astronomy from the University of Wisconsin. After postdoctoral appointments at the University of Wisconsin and Brookhaven National Laboratory, he joined the staff of Argonne National Laboratory in 1966, working in the fields of experimental high-energy physics and accelerator physics. He joined the Accelerator Technology Division at Los Alamos National Laboratory in 1979, where he specialized in high-current beam physics and linear accelerator design and technology. In 2007

  12. Auroral electron acceleration

    International Nuclear Information System (INIS)

    Bryant, D.A.

    1989-10-01

    Two theories of auroral electron acceleration are discussed. Part 1 examines the currently widely held view that the acceleration is an ordered process in a quasi-static electric field. It is suggested that, although there are many factors seeming to support this theory, the major qualifications and uncertainties that have been identified combine to cast serious doubt over its validity. Part 2 is devoted to a relatively new interpretation in terms of stochastic acceleration in turbulent electric fields. This second theory, which appears to account readily for most known features of the electron distribution function, is considered to provide a more promising approach to this central question in magnetospheric plasma physics. (author)

  13. New accelerator ideas

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1985-05-15

    In the past, providing higher particle beam energies meant building bigger accelerators. It is now universally accepted that with the current generation of accelerator projects either under construction (such as LEP at CERN) or proposed (such as the Superconducting Super Collider in the US), conventional techniques are reaching their practical limit. With the growing awareness that progress in particle physics requires new methods to accelerate particles, workshops and study groups are being set up across the world to search for ideas for the machines of tomorrow.

  14. Advanced Accelerator Concepts

    Science.gov (United States)

    Siemann, Robert

    1998-04-01

    Current particle accelerators rely on conventional or superconducting radio frequency cavities to accelerate beams of protons or electrons for nuclear and particle research and for medical and materials science studies. New methods for achieving larger accelerating gradients have been proposed and are being studied. These include the use of high power lasers, laser driven plasmas, wake fields generated by intense low energy beams, and millimeter wavelength EM structures. The studies to date, and the prospects for practical applications of these new ideas will be discussed.

  15. Accelerators Spanish steps

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    In September, the CERN Accelerator School (CAS) held its third General Accelerator Physics Course, the venue this time being Salamanca, the oldest university in Spain. Spain, which rejoined CERN in 1982, now has a vigorous and steadily growing high energy physics community making substantial contributions to physics detector development and successfully involving Spanish industry. However the embryonic accelerator community cannot yet generate an equivalent level of activity, and this important channel for introducing new high technology into industry has yet to be fully exploited

  16. Extinction Events Can Accelerate Evolution

    DEFF Research Database (Denmark)

    Lehman, Joel; Miikkulainen, Risto

    2015-01-01

    Extinction events impact the trajectory of biological evolution significantly. They are often viewed as upheavals to the evolutionary process. In contrast, this paper supports the hypothesis that although they are unpredictably destructive, extinction events may in the long term accelerate...... evolution by increasing evolvability. In particular, if extinction events extinguish indiscriminately many ways of life, indirectly they may select for the ability to expand rapidly through vacated niches. Lineages with such an ability are more likely to persist through multiple extinctions. Lending...... computational support for this hypothesis, this paper shows how increased evolvability will result from simulated extinction events in two computational models of evolved behavior. The conclusion is that although they are destructive in the short term, extinction events may make evolution more prolific...

  17. Risk factor studies of age-at-onset in a sample ascertained for Parkinson disease affected sibling pairs: a cautionary tale

    OpenAIRE

    Wilk, Jemma B; Lash, Timothy L

    2007-01-01

    Abstract An association between exposure to a risk factor and age-at-onset of disease may reflect an effect on the rate of disease occurrence or an acceleration of the disease process. The difference in age-at-onset arising from case-only studies, however, may also reflect secular trends in the prevalence of exposure to the risk factor. Comparisons of age-at-onset associated with risk factors are commonly performed in case series enrolled for genetic linkage analysis of late onset diseases. W...

  18. Accelerated cleanup risk reduction

    International Nuclear Information System (INIS)

    Knapp, R.B.; Aines, R.M.; Blake, R.G.; Copeland, A.B.; Newmark, R.L.; Tompson, A.F.B.

    1998-01-01

    There is no proven technology for remediating contaminant plume source regions in a heterogeneous subsurface. This project is an interdisciplinary effort to develop the requisite new technologies so that will be rapidly accepted by the remediation community. Our technology focus is hydrous pyrolysis/oxidation (HPO) which is a novel in situ thermal technique. We have expanded this core technology to leverage the action of steam injection and place an in situ microbial filter downstream to intercept and destroy the accelerated movement of contaminated groundwater. Most contaminant plume source regions, including the chlorinated solvent plume at LLNL, are in subsurface media characterized by a wide range in hydraulic conductivity. At LLNL, the main conduits for contaminant transport are buried stream channels composed of gravels and sands; these have a hydraulic conductivity in the range of 10 -1 to 10 -2 cm/s. Clay and silt units with a hydraulic conductivity of 10 -1 to 10 -6 cm/s bound these buried channels; these are barriers to groundwater movement and contain the highest contaminant concentrations in the source region. New remediation technologies are required because the current ones preferentially access the high conductivity units. HPO is an innovative process for the in situ destruction of contaminants in the entire subsurface. It operates by the injection of steam. We have demonstrated in laboratory experiments that many contaminants rapidly oxidize to harmless compounds at temperatures easily achieved by injecting steam, provided sufficient dissolved oxygen is present. One important challenge in a heterogeneous source region is getting heat, contaminants, and an oxidizing agent in the same place at the same time. We have used the NUFT computer program to simulate the cyclic injection of steam into a contaminated aquifer for design of a field demonstration. We used an 8 hour, steam/oxygen injection cycle followed by a 56 hour relaxation period in which the

  19. Crowdsourced Translation for Rapid Internationalization in Cyberspace

    DEFF Research Database (Denmark)

    Tran, Yen; Yonatany, Moshe; Mahnke, Volker

    2016-01-01

    This paper explores how Facebook effectively used crowdsourced translation to accelerate its rapid internationalization. We apply the learning perspective of internationalization theory to unpack what the firm learned in order to mobilize crowd-based knowledge to facilitate internationalization...... and codified knowledge, rather than the experiential knowledge traditionally suggested in the literature on the process of internationalization, and (2) the firm's success rested on its ability to use virtual learning tools and incentive systems to acquire, articulate and integrate knowledge from communities...... of internationally dispersed users – the “crowd” – to accelerate its internationalization in cyberspace. This empirical study extends internationalization theory regarding knowledge and organizational learning....

  20. Non-atopic males with adult onset asthma are at risk of persistent airflow limitation

    NARCIS (Netherlands)

    Amelink, M.; de Nijs, S. B.; Berger, M.; Weersink, E. J.; ten Brinke, A.; Sterk, P. J.; Bel, E. H.

    2012-01-01

    Background Patients with asthma have on average a more rapid decline in FEV1 as compared with the general population. Recent cluster analysis has revealed different asthma phenotypes that can be distinguished by age of onset and reversibility of airflow limitation. Objective This study aimed at

  1. Older adults in jail: high rates and early onset of geriatric conditions.

    Science.gov (United States)

    Greene, Meredith; Ahalt, Cyrus; Stijacic-Cenzer, Irena; Metzger, Lia; Williams, Brie

    2018-02-17

    The number of older adults in the criminal justice system is rapidly increasing. While this population is thought to experience an early onset of aging-related health conditions ("accelerated aging"), studies have not directly compared rates of geriatric conditions in this population to those found in the general population. The aims of this study were to compare the burden of geriatric conditions among older adults in jail to rates found in an age-matched nationally representative sample of community dwelling older adults. This cross sectional study compared 238 older jail inmates age 55 or older to 6871 older adults in the national Health and Retirement Study (HRS). We used an age-adjusted analysis, accounting for the difference in age distributions between the two groups, to compare sociodemographics, chronic conditions, and geriatric conditions (functional, sensory, and mobility impairment). A second age-adjusted analysis compared those in jail to HRS participants in the lowest quintile of wealth. All geriatric conditions were significantly more common in jail-based participants than in HRS participants overall and HRS participants in the lowest quintile of net worth. Jail-based participants (average age of 59) experienced four out of six geriatric conditions at rates similar to those found in HRS participants age 75 or older. Geriatric conditions are prevalent in older adults in jail at significantly younger ages than non-incarcerated older adults suggesting that geriatric assessment and geriatric-focused care are needed for older adults cycling through jail in their 50s and that correctional clinicians require knowledge about geriatric assessment and care.

  2. Voice Onset Time in Azerbaijani Consonants

    Directory of Open Access Journals (Sweden)

    Ali Jahan

    2009-10-01

    Full Text Available Objective: Voice onset time is known to be cue for the distinction between voiced and voiceless stops and it can be used to describe or categorize a range of developmental, neuromotor and linguistic disorders. The aim of this study is determination of standard values of voice onset time for Azerbaijani language (Tabriz dialect. Materials & Methods: In this description-analytical study, 30 Azeris persons whom were selected conveniently by simple selection, uttered 46 monosyllabic words initiating with 6 Azerbaijani stops twice. Using Praat software, the voice onset time values were analyzed by waveform and wideband spectrogram in milliseconds. Vowel effect, sex differences and the effect of place of articulation on VOT, were evaluated and data were analyzed by one-way ANOVA test. Results: There was no significant difference in voice onset time between male and female Azeris speakers (P<0.05. Vowel and place of articulation had significant correlation with voice onset time (P<0.001. Voice onset time values for /b/, /p/, /d/, /t/, /g/, /k/, and [c], [ɟ] allophones were 10.64, 86.88, 13.35, 87.09, 26.25, 100.62, 131.19, 63.18 mili second, respectively. Conclusion: Voice onset time values are the same for Azerbaijani men and women. However, like many other languages, back and high vowels and back place of articulation lengthen VOT. Also, voiceless stops are aspirated in this language and voiced stops have positive VOT values.

  3. Early onset depression: the relevance of anxiety.

    Science.gov (United States)

    Parker, G; Wilhelm, K; Asghari, A

    1997-01-01

    The aim of this study was to determine risk factors that may differentiate early onset from late onset depression. A non-clinical cohort that had been assessed from 1978 to 1993 at 5 yearly intervals and that had a high prevalence rate of lifetime depression took part in the study. We established an appropriate age cut-off to distinguish early onset (i.e. before 26 years) of major and of minor depression, and examined the relevance of a number of possible determinants of early onset depression assessed over the life of the study. Despite several dimensional measures of depression, self-esteem and personality being considered, they generally failed (when assessed early in the study) to discriminate subsequent early onset depression, with the exception of low masculinity scores being a weak predictor of major and/or minor depression. Early onset depression was strongly predicted, however, by a lifetime episode of a major anxiety disorder, with generalised anxiety being a somewhat stronger and more consistent predictor than panic disorder, agoraphobia and minor anxiety disorders (ie social phobia, simple phobia). The possibility that anxiety may act as a key predispositional factor to early onset depression and to a greater number of depressive episodes is important in that clinical assessment and treatment of any existing anxiety disorder may be a more efficient and useful strategy than focussing primarily on the depressive disorder.

  4. Age at onset and Parkinson disease phenotype

    Science.gov (United States)

    Pagano, Gennaro; Ferrara, Nicola; Brooks, David J.

    2016-01-01

    Objective: To explore clinical phenotype and characteristics of Parkinson disease (PD) at different ages at onset in recently diagnosed patients with untreated PD. Methods: We have analyzed baseline data from the Parkinson's Progression Markers Initiative database. Four hundred twenty-two patients with a diagnosis of PD confirmed by DaTSCAN imaging were divided into 4 groups according to age at onset (onset younger than 50 years, 50–59 years, 60–69 years, and 70 years or older) and investigated for differences in side, type and localization of symptoms, occurrence/severity of motor and nonmotor features, nigrostriatal function, and CSF biomarkers. Results: Older age at onset was associated with a more severe motor and nonmotor phenotype, a greater dopaminergic dysfunction on DaTSCAN, and reduction of CSF α-synuclein and total tau. The most common presentation was the combination of 2 or 3 motor symptoms (bradykinesia, resting tremor, and rigidity) with rigidity being more common in the young-onset group. In about 80% of the patients with localized onset, the arm was the most affected part of the body, with no difference across subgroups. Conclusions: Although the presentation of PD symptoms is similar across age subgroups, the severity of motor and nonmotor features, the impairment of striatal binding, and the levels of CSF biomarkers increase with age at onset. The variability of imaging and nonimaging biomarkers in patients with PD at different ages could hamper the results of future clinical trials. PMID:26865518

  5. Accelerated variant of idiopathic pulmonary fibrosis: clinical behavior and gene expression pattern.

    Directory of Open Access Journals (Sweden)

    Moisés Selman

    Full Text Available BACKGROUND: Idiopathic pulmonary fibrosis (IPF is characterized by the insidious onset of dyspnea or cough. However, a subset of patients has a short duration of symptoms with rapid progression to end-stage disease. In this study, we evaluated clinical and molecular features of "rapid" and "slow" progressors with IPF. METHODS AND FINDINGS: 26 patients with 24 months of symptoms [slow progressors] were studied. Survival was analyzed by the Kaplan-Meyer method and proportional hazard's model. Lung microarrays and tissue proteins were measured in a subset of patients. No differences were found in age, physiologic impairment and bronchoalveolar lavage (BAL cellular profile. There were more males (OR = 6.5; CI:1.4-29.5; p = 0.006 and smokers (OR = 3.04; CI:1.1-8.3; p = 0.04 in the rapid progressors group. Survival from the beginning of symptoms was significantly reduced in rapid progressors (HR = 9.0; CI:4.48-18.3; p2-fold increase of active matrix metalloproteinase-9, and induced a higher fibroblast migration compared with slow progressors and controls [238+/-98% versus 123+/-29% (p<0.05 and 30+/-17% (p<0.01]. CONCLUSIONS/SIGNIFICANCE: A subgroup of IPF patients, predominantly smoking males, display an accelerated clinical course and have a gene expression pattern that is different from those with slower progression and longer survival. These findings highlight the variability in the progression of IPF, and may explain, in part, the difficulty in obtaining significant and reproducible results in studies of therapeutic interventions in patients with IPF.

  6. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  7. Future accelerators: physics issues

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1977-11-01

    High energy physics of the future using future accelerators is discussed. The proposed machines and instruments, physics issues and opportunities including brief sketches of outstanding recent results, and the way the proposed machines address these issues are considered. 42 references

  8. Compact particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.

  9. The accelerator breeder

    International Nuclear Information System (INIS)

    Johansson, E.

    1986-01-01

    Interactions of high-energy particles with atomic nuclei, in particular heavy ones, leads to a strong emission of neutrons. Preferably these high-energy particles are protons or deuterons obtained from a linear accelerator. The neutrons emitted are utilized in the conversion of U238 to Pu239 or of Th232 to U233. The above is the basis of the accelerator breeder, a concept studied abroad in many variants. No such breeder has, however, so far been built, but there exists vast practical experience on the neutron production and on the linear accelerator. Some of the variants mentioned are described in the report, after a presentation of general characteristics for the particle-nucleus interaction and for the linear accelerator. (author)

  10. Accelerate Water Quality Improvement

    Science.gov (United States)

    EPA is committed to accelerating water quality improvement and minimizing negative impacts to aquatic life from contaminants and other stressors in the Bay Delta Estuary by working with California Water Boards to strengthen water quality improvement plans.

  11. Rejuvenating CERN's Accelerators

    CERN Multimedia

    2004-01-01

    In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

  12. Wake field acceleration experiments

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

  13. Accelerated test program

    Science.gov (United States)

    Ford, F. E.; Harkness, J. M.

    1977-01-01

    A brief discussion on the accelerated testing of batteries is given. The statistical analysis and the various aspects of the modeling that was done and the results attained from the model are also briefly discussed.

  14. IAE pulsed electrostatic accelerator

    International Nuclear Information System (INIS)

    Afanas'ev, V.P.; Ganzhelyuk, M.L.; Kozlov, L.D.; Koltypin, E.A.; Molchanov, Yu.D.; Otroshchenko, G.A.; Yan'kov, G.B.

    1976-01-01

    The modernized pulse electrostatic accelerator using the klystron ion grouping and the beam interruption system prior to acceleration is described. The accelerator is modernized in order to improve parameters of a current pulse and to decrease the background in the measurement room. The ion beam of needed dimensions is obtained with the help of a high-frequency source and a beam grouping and deflection system. The general view of the beam grouping and deflection system is shown. The ion beam forming process is considered in detail. The modernized electrostatic accelerator permits to obtain a pulse current with a pulse length of 1.5 ns and an amplitude of 1.5 - 2 μA. With the repetition frequency of 2 MHz, the average target current is about 6 μA

  15. Ionization front accelerator

    International Nuclear Information System (INIS)

    Olson, C.L.

    1975-01-01

    In a recently proposed linear collective accelerator, ions are accelerated in a steep, moving potential well created at the head of an intense relativistic electron beam. The steepness of the potential well and its motion are controlled by the external ionization of a suitable background gas. Calculations concerning optimum choices for the background gas and the ionization method are presented; a two-step photoionization process employing Cs vapor is proposed. In this process, a super-radiant light source is used to excite the gas, and a UV laser is used to photoionize the excited state. The appropriate line widths and coupled ionization growth rate equations are discussed. Parameter estimates are given for a feasibility experiment, for a 1 GeV proton accelerator, and for a heavy ion accelerator (50 MeV/nucleon uranium). (auth)

  16. HEAVY ION LINEAR ACCELERATOR

    Science.gov (United States)

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  17. Advances in electrostatic accelerators

    International Nuclear Information System (INIS)

    Wegner, H.E.

    1975-01-01

    Advances in the design and performance of electrostatic accelerators since 1969 are reviewed with special emphasis on the ''forefront'' accelerators that are currently leading in voltage capability. A comparison of the acceleration tube design offered by the National Electrostatics Corporation and the High Voltage Engineering Corporation is also made. Other methods of increasing heavy ion energy by means of dual foil stripping are discussed as well as the performance of a newly developed sputter ion source for the production of negative heavy ions with reliability and flexibility that greatly exceeds all other present systems. Finally, new developments in terms of both booster systems and very high voltage electrostatic accelerators (25 to 60 MV) are discussed. (U.S.)

  18. Iteration and accelerator dynamics

    International Nuclear Information System (INIS)

    Peggs, S.

    1987-10-01

    Four examples of iteration in accelerator dynamics are studied in this paper. The first three show how iterations of the simplest maps reproduce most of the significant nonlinear behavior in real accelerators. Each of these examples can be easily reproduced by the reader, at the minimal cost of writing only 20 or 40 lines of code. The fourth example outlines a general way to iteratively solve nonlinear difference equations, analytically or numerically

  19. High energy medical accelerators

    International Nuclear Information System (INIS)

    Mandrillon, P.

    1990-01-01

    The treatment of tumours with charged particles, ranging from protons to 'light ions' (carbon, oxygen, neon), has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. These high energy medical accelerators are presented in this paper. (author) 15 refs.; 14 figs.; 8 tabs

  20. Vancouver Accelerator Conference

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1985-06-15

    Anyone who contends that particle physics is conducted in an ivory tower, not contributing to other fields of science or to humanity at large, should have attended the 1985 Particle Accelerator Conference in Vancouver. Over a thousand participants contributed 781 papers and only a fraction were actually related to accelerators for high energy physics. The majority of present developments are in the service of other fields of science, for alternative power sources, for medicine, for industrial applications, etc.

  1. A symmetrical rail accelerator

    International Nuclear Information System (INIS)

    Igenbergs, E.

    1991-01-01

    This paper reports on the symmetrical rail accelerator that has four rails, which are arranged symmetrically around the bore. The opposite rails have the same polarity and the adjacent rails the opposite polarity. In this configuration the radial force acting upon the individual rails is significantly smaller than in a conventional 2-rail configuration and a plasma armature is focussed towards the axis of the barrel. Experimental results indicate a higher efficiency compared to a conventional rail accelerator

  2. Ion optics for accelerators

    International Nuclear Information System (INIS)

    Enge, H.A.

    1974-01-01

    A review is given of ion-optic devices used in particle accelerators, including electrostatic lenses, magnetic quadrupoles, and deflecting magnets. Tube focusing in dc accelerators is also treated, and a novel scheme for shaping the electrodes to produce strong focusing is described. The concepts of emittance (phase space) and emittance conservation are briefly discussed. Chromatic and spatial aberrations are introduced, and it is shown how they can be calculated and sometimes substantially reduced. Some examples are given

  3. An active particle accelerator

    International Nuclear Information System (INIS)

    Goldman, T.

    1991-01-01

    Although a static charge is difficult to maintain on macroscopic particles, it is straightforward to construct a small object with a regularly oscillating electric dipole moment. For objects of a given size, one may then construct an accelerator by appropriately matching the frequency and separations of an external array of electrodes to this size. Physically feasible size ranges, an accelerator design, and possible applications of such systems are discussed. 8 refs., 9 figs

  4. Vancouver Accelerator Conference

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Anyone who contends that particle physics is conducted in an ivory tower, not contributing to other fields of science or to humanity at large, should have attended the 1985 Particle Accelerator Conference in Vancouver. Over a thousand participants contributed 781 papers and only a fraction were actually related to accelerators for high energy physics. The majority of present developments are in the service of other fields of science, for alternative power sources, for medicine, for industrial applications, etc

  5. CEBAF Accelerator Achievements

    International Nuclear Information System (INIS)

    Chao, Y C; Drury, M; Hovater, C; Hutton, A; Krafft, G A; Poelker, M; Reece, C; Tiefenback, M

    2011-01-01

    In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

  6. Collective field accelerator

    International Nuclear Information System (INIS)

    Luce, J.S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a ν/γ of approx. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam

  7. Biallelic Mutations in TBCD, Encoding the Tubulin Folding Cofactor D, Perturb Microtubule Dynamics and Cause Early-Onset Encephalopathy.

    Science.gov (United States)

    Flex, Elisabetta; Niceta, Marcello; Cecchetti, Serena; Thiffault, Isabelle; Au, Margaret G; Capuano, Alessandro; Piermarini, Emanuela; Ivanova, Anna A; Francis, Joshua W; Chillemi, Giovanni; Chandramouli, Balasubramanian; Carpentieri, Giovanna; Haaxma, Charlotte A; Ciolfi, Andrea; Pizzi, Simone; Douglas, Ganka V; Levine, Kara; Sferra, Antonella; Dentici, Maria Lisa; Pfundt, Rolph R; Le Pichon, Jean-Baptiste; Farrow, Emily; Baas, Frank; Piemonte, Fiorella; Dallapiccola, Bruno; Graham, John M; Saunders, Carol J; Bertini, Enrico; Kahn, Richard A; Koolen, David A; Tartaglia, Marco

    2016-10-06

    Microtubules are dynamic cytoskeletal elements coordinating and supporting a variety of neuronal processes, including cell division, migration, polarity, intracellular trafficking, and signal transduction. Mutations in genes encoding tubulins and microtubule-associated proteins are known to cause neurodevelopmental and neurodegenerative disorders. Growing evidence suggests that altered microtubule dynamics may also underlie or contribute to neurodevelopmental disorders and neurodegeneration. We report that biallelic mutations in TBCD, encoding one of the five co-chaperones required for assembly and disassembly of the αβ-tubulin heterodimer, the structural unit of microtubules, cause a disease with neurodevelopmental and neurodegenerative features characterized by early-onset cortical atrophy, secondary hypomyelination, microcephaly, thin corpus callosum, developmental delay, intellectual disability, seizures, optic atrophy, and spastic quadriplegia. Molecular dynamics simulations predicted long-range and/or local structural perturbations associated with the disease-causing mutations. Biochemical analyses documented variably reduced levels of TBCD, indicating relative instability of mutant proteins, and defective β-tubulin binding in a subset of the tested mutants. Reduced or defective TBCD function resulted in decreased soluble α/β-tubulin levels and accelerated microtubule polymerization in fibroblasts from affected subjects, demonstrating an overall shift toward a more rapidly growing and stable microtubule population. These cells displayed an aberrant mitotic spindle with disorganized, tangle-shaped microtubules and reduced aster formation, which however did not alter appreciably the rate of cell proliferation. Our findings establish that defective TBCD function underlies a recognizable encephalopathy and drives accelerated microtubule polymerization and enhanced microtubule stability, underscoring an additional cause of altered microtubule dynamics with

  8. CEBAF: Accelerating cavities look good

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-09-15

    The first assembled pairs of superconducting accelerating cavities from German supplier Interatom for the Continuous Electron Beam Accelerator Facility, Newport News, Virginia, have exceeded performance specifications.

  9. CEBAF: Accelerating cavities look good

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The first assembled pairs of superconducting accelerating cavities from German supplier Interatom for the Continuous Electron Beam Accelerator Facility, Newport News, Virginia, have exceeded performance specifications

  10. JAERI 20 MV tandem accelerator

    International Nuclear Information System (INIS)

    Tsukada, Kineo; Harada, Kichinosuke

    1977-01-01

    Accelerators have been developed as the experimental apparatuses for the studies on nuclei and elementary particles. One direction of the development is the acceleration of protons and electrons to more and more high energy, and another direction is the acceleration of heavy ions up to uranium to several MeV up to several hundreds MeV. However recently, accelerators are used as the useful tools for the studies in wider fields. There are electrostatic acceleration and high frequency acceleration in ion acceleration, and at present, super-large accelerators are high frequency acceleration type. In Japan Atomic Energy Research Institute, it was decided in 1975 to construct an electrostatic accelerator of tandem type in order to accelerate heavy ions. In case of the electrostatic acceleration, the construction is relatively simple, the acceleration of heavy ions is easy, the property of the ion beam is very good, and the energy is stable. Especially, the tandem type is convenient for obtaining high energy. The tandem accelerator of 20 MV terminal voltage was ordered from the National Electrostatics Corp., USA, and is expected to be completed in 1978. The significance of heavy ion acceleration in the development and research of atomic energy, tandem van de Graaff accelerators, the JAERI 20MV tandem accelerator, and the research project with this accelerator are described. (Kako, I.)

  11. APT accelerator technology

    International Nuclear Information System (INIS)

    Schneider, J. David

    1996-01-01

    The proposed accelerator production of tritium (APT) project requires an accelerator that provides a cw proton beam of 100 m A at 1300 MeV. Since the majority of the technical risk of a high-current cw (continuous-wave, 100% DF) accelerator resides in the low-energy section, Los Alamos is building a 20 MeV duplicate of the accelerator front end to confirm design codes, beam performance, and demonstrate operational reliability. We report on design details of this low-energy demonstration accelerator (LEDA) and discuss the integrated design of the full accelerator for the APT plant. LEDA's proton injector is under test and has produced more than 130 mA at 75 keV. Fabrication is proceeding on a 6.7- MeV, 8-meter-long RFQ, and detailed design is underway on coupled-cavity drift-tube linac (CCDTL) structures. In addition, detailed design and technology experiments are underway on medium-beta superconducting cavities to assess the feasibility of replacing the conventional (room-temperature copper) high-energy linac with a linac made of niobium superconducting RF cavities. (author)

  12. Laser wakefield acceleration

    International Nuclear Information System (INIS)

    Esarey, E.; Ting, A.; Sprangle, P.

    1989-01-01

    The laser wakefield accelerator (LWFA) is a novel plasma based electron acceleration scheme which utilizes a relativistic optical guiding mechanism for laser pulse propagation. In the LWFA, a short, high power, single frequency laser pulse is propagated through a plasma. As the laser pulse propagates, its radial and axial ponderomotive forces nonresonantly generate large amplitude plasma waves (wakefields) with a phase velocity equal to the group velocity of the pulse. A properly phased electron bunch may then be accelerated by the axial wakefield and focused by the transverse wakefield. Optical guiding of the laser pulse in the plasma is necessary in order to achieve high energies in a single stage of acceleration. At sufficiently high laser powers, optical guiding may be achieved through relativistic effects associated with the plasma electrons. Preliminary analysis indicates that this scheme may overcome some of the difficulties present in the plasma beat wave accelerator and in the plasma wakefield accelerator. Analytical and numerical calculations are presented which study both laser pulse propagation within a plasma as well as the subsequent generation of large amplitude plasma waves. In addition, the generation of large amplitude plasma waves in regimes where the plasma waves become highly nonlinear is examined

  13. Optimizing conditions for an accelerated leach test

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Fuhrmann, M.; Heiser, J.; Franz, E.M.; Colombo, P.

    1988-01-01

    An accelerated leach test for low-level radioactive waste forms is being developed to provide, in a short time, data that can be extrapolated to long time periods. The approach is to provide experimental conditions that will accelerate leaching without changing the dominant release mechanism. Experimental efforts have focused on combining individual factors that have been observed to accelerate leaching. These include elevated temperature, increased leachant volume, and reduced specimen size. The response of diffusion coefficients to various acceleration factors have been evaluated and provide information on experimental parameters that need to be optimized to increase leach rates. Preliminary modeling using a diffusion mechanism (allowing for depletion) of a finite cylinder geometry indicates that during early portions of experiments (daily sampling intervals), leaching is diffusion controlled and more rapid than later in the same experiments (weekly or greater sampling intervals). For cement waste forms, this reduction in rate may be partially controlled by changes in physical structure and chemistry (sometimes related to environmental influences such as CO 2 ), but it is more likely associated with the duration of the sampling interval. By using a combination of mathematical modeling and by experimentally investigating various leach rate controlling factors, a more complete understanding of leaching processes is being developed. This, in turn, is leading to optimized accelerating conditions for a leach test

  14. Photon acceleration in laser wakefield accelerators

    International Nuclear Information System (INIS)

    Trines, R. M. G. M.

    2007-01-01

    If the index of a refraction of a dispersive medium, such as a plasma, changes in time, it can be used to change the frequency of light propagating through the medium. This effect is called photon acceleration. It has been predicted in both theory and simulations, and also been demonstrated experimentally for the case of moving ionization fronts in gases (the so-called ionization blueshift) as well as for laser-driven wakefields.Here, we present studies of photon acceleration in laser-driven plasma wakefields. The unique spectral characteristics of this process will be discussed, to distinguish it from e.g. photon acceleration by ionization fronts, frequency domain interferometry or self-phase modulation. The dynamics of the photons in laser-wakefield interaction are studied through both regular particle-in-cell and wave-kinetic simulations. The latter approach provides a powerful, versatile, and easy-to-use method to track the propagation of individual spectral components, providing new insight into the physics of laser-plasma interaction. Theory, simulations and experimental results will be brought together to provide a full understanding of the dynamics of a laser pulse in its own wakefield.Even though the wave-kinetic approach mentioned above has mainly been developed for the description of laser-plasma interaction, it can be applied to a much wider range of fast wave-slow wave interaction processes: Langmuir waves-ion acoustic waves, drift waves-zonal flow, Rossby waves-zonal flow, or even photons-gravitational waves. Several recent results in these areas will be shown, often with surprising results

  15. ONSETS AND SPECTRA OF IMPULSIVE SOLAR ENERGETIC ELECTRON EVENTS OBSERVED NEAR THE EARTH

    International Nuclear Information System (INIS)

    Kontar, Eduard P.; Reid, Hamish A. S.

    2009-01-01

    Impulsive solar energetic electrons are often observed in the interplanetary space near the Earth and have an attractive diagnostic potential for poorly understood solar flare acceleration processes. We investigate the transport of solar flare energetic electrons in the heliospheric plasma to understand the role of transport to the observed onset and spectral properties of the impulsive solar electron events. The propagation of energetic electrons in solar wind plasma is simulated from the acceleration region at the Sun to the Earth, taking into account self-consistent generation and absorption of electrostatic electron plasma (Langmuir) waves, effects of nonuniform plasma, collisions, and Landau damping. The simulations suggest that the beam-driven plasma turbulence and the effects of solar wind density inhomogeneity play a crucial role and lead to the appearance of (1) a spectral break for a single power-law injected electron spectrum, with the spectrum flatter below the break, (2) apparent early onset of low-energy electron injection, and (3) the apparent late maximum of low-energy electron injection. We show that the observed onsets, spectral flattening at low energies, and formation of a break energy at tens of keV is the direct manifestation of wave-particle interactions in nonuniform plasma of a single accelerated electron population with an initial power-law spectrum.

  16. Accelerator business in Japan expanding

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Accelerators have become to be used increasingly in Japan in such fields as medicine, physics research and industry. This has caused stiff competition for market share by the manufacturers of accelerators. Electron beam accelerators for industrial use provide an indispensable means for adding values to products, for example, electric cables with incombustible insulators. Linear accelerators for the nondestructive inspection of nuclear components have been widely installed at equipment manufacturing plants. Active efforts have been exerted to develop small synchrotron radiation accelerators for next generation electronic industry. Cyclotrons for producing short life radioisotopes for medical diagnosis and electron beam accelerators for radiation therapy are also used routinely. The suppliers of accelerators include the companies manufacturing heavy electric machinery, heavy machinery and the engineering division of steelmakers. Accelerator physics is being formed, but universities do not yet offer the course regarding accelerators. Accelerator use in Japan and the trend of accelerator manufacturers are reported. (K.I.)

  17. Late onset depression: A recent update

    Directory of Open Access Journals (Sweden)

    Ananya Mahapatra

    2015-01-01

    Full Text Available Late onset depression has recently emerged as a serious mental health issue in the geriatric population with significant public health implications. It is often challenging to diagnose and treat this entity. Various theories have been postulated to elucidate the etiology of late onset depression, but a unifying hypothesis is lacking. Although the vascular hypothesis is most researched; a complex interaction of multiple vulnerability factors is the current focus of attention. Numerous psychosocial variables have been implicated to play a significant role in predicting the onset and severity of late-life depression. Phenomenological differences have been delineated from depression occurring at a younger age, but the findings are equivocal. A better understanding of the natural trajectory of depression in the elderly is required for early diagnosis and effective treatment. This review attempts to summarize the current status of evidence regarding epidemiology, etiology, clinical features, and treatment options available for late-onset depression.

  18. Early- and Late-Onset Inherited Erythromelalgia

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-08-01

    Full Text Available A genotype-phenotype relationship at the clinical, cellular and molecular levels is shown in a case of erythromelalgia of relatively late onset, in a study at Yale University School of Medicine, and centers in China.

  19. Genetics Home Reference: early-onset glaucoma

    Science.gov (United States)

    ... called a syndrome. If glaucoma appears before the age of 5 without other associated abnormalities, it is called primary congenital glaucoma. Other individuals experience early onset of primary open-angle glaucoma, the most ...

  20. Onset in-river conductivity sonde data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Onset HOBO Model U24-01 in-river sondes were deployed to measure water temperature and electrical conductivity at each of the ISCO sampling sites at 5 min intervals....

  1. Beam transport through electrostatic accelerators and matching into post accelerators

    International Nuclear Information System (INIS)

    Larson, J.D.

    1986-01-01

    Ion beam transport through electrostatic acceleration is briefly reviewed. Topics discussed include injection, matching into the low-energy acceleration stage, matching from the terminal stripper into the high-energy stage, transport to a post accelerator, space charge, bunching isochronism, dispersion and charge selection. Beam transport plans for the proposed Vivitron accelerator are described. (orig.)

  2. Risk factor studies of age-at-onset in a sample ascertained for Parkinson disease affected sibling pairs: a cautionary tale.

    Science.gov (United States)

    Wilk, Jemma B; Lash, Timothy L

    2007-04-04

    An association between exposure to a risk factor and age-at-onset of disease may reflect an effect on the rate of disease occurrence or an acceleration of the disease process. The difference in age-at-onset arising from case-only studies, however, may also reflect secular trends in the prevalence of exposure to the risk factor. Comparisons of age-at-onset associated with risk factors are commonly performed in case series enrolled for genetic linkage analysis of late onset diseases. We describe how the results of age-at-onset studies of environmental risk factors reflect the underlying structure of the source population, rather than an association with age-at-onset, by contrasting the effects of coffee drinking and cigarette smoking on Parkinson disease age-at-onset with the effects on age-at-enrollment in a population based study sample. Despite earlier evidence to suggest a protective association of coffee drinking and cigarette smoking with Parkinson disease risk, the age-at-onset results are comparable to the patterns observed in the population sample, and thus a causal inference from the age-at-onset effect may not be justified. Protective effects of multivitamin use on PD age-at-onset are also shown to be subject to a bias from the relationship between age and multivitamin initiation. Case-only studies of age-at-onset must be performed with an appreciation for the association between risk factors and age and ageing in the source population.

  3. Progression of Late-Onset Stargardt Disease

    OpenAIRE

    Lambertus, Stanley; Lindner, Moritz; Bax, Nathalie M.; Mauschitz, Matthias M.; Nadal, Jennifer; Schmid, Matthias; Schmitz-Valckenberg, Steffen; den Hollander, Anneke I.; Weber, Bernhard H. F.; Holz, Frank G.; van der Wilt, Gert Jan; Fleckenstein, Monika; Hoyng, Carel B.

    2016-01-01

    Purpose: Identification of sensitive biomarkers is essential to determine potential effects of emerging therapeutic trials for Stargardt disease. This study aimed to describe the natural history of late-onset Stargardt, and demonstrates the accuracy of retinal pigment epithelium (RPE) atrophy progression as an outcome measure. Methods: We performed a retrospective cohort study collecting multicenter data from 47 patients (91 eyes) with late-onset Stargardt, defined by clinical phenotype...

  4. Attention capture by contour onsets and offsets: no special role for onsets.

    Science.gov (United States)

    Watson, D G; Humphreys, G W

    1995-07-01

    In five experiments, we investigated the power of targets defined by the onset or offset of one of an object's parts (contour onsets and offsets) either to guide or to capture visual attention. In Experiment 1, search for a single contour onset target was compared with search for a single contour offset target against a static background of distractors; no difference was found between the efficiency with which each could be detected. In Experiment 2, onsets and offsets were compared for automatic attention capture, when both occurred simultaneously. Unlike in previous studies, the effects of overall luminance change, new-object creation, and number of onset and offset items were controlled. It was found that contour onset and offset items captured attention equally well. However, display size effects on both target types were also apparent. Such effects may have been due to competition for selection between multiple onset and offset stimuli. In Experiments 3 and 4, single onset and offset stimuli were presented simultaneously and pitted directly against one another among a background of static distractors. In Experiment 3, we examined "guided search," for a target that was formed either from an onset or from an offset among static items. In Experiment 4, the onsets and offsets were uncorrelated with the target location. Similar results occurred in both experiments: target onsets and offsets were detected more efficiently than static stimuli which needed serial search; there remained effects of display size on performance; but there was still no advantage for onsets. In Experiment 5, we examined automatic attention capture by single onset and offset stimuli presented individually among static distractors. Again, there was no advantage for onset over offset targets and a display size effect was also present. These results suggest that, both in isolation and in competition, onsets that do not form new objects neither guide nor gain automatic attention more efficiently

  5. ORNL pellet acceleration program

    International Nuclear Information System (INIS)

    Foster, C.A.; Milora, S.L.

    1978-01-01

    The Oak Ridge National Laboratory (ORNL) pellet fueling program is centered around developing equipment to accelerate large pellets of solidified hydrogen to high speeds. This equipment will be used to experimentally determine pellet-plasma interaction physics on contemporary tokamaks. The pellet experiments performed on the Oak Ridge Tokamak (ORMAK) indicated that much larger, faster pellets would be advantageous. In order to produce and accelerate pellets of the order of 1 to 6 mm in diameter, two apparatuses have been designed and are being constructed. The first will make H 2 pellets by extruding a filament of hydrogen and mechanically chopping it into pellets. The pellets formed will be mechanically accelerated with a high speed arbor to a speed of 950 m/sec. This technique may be extended to speeds up to 5000 m/sec, which makes it a prime candidate for a reactor fueling device. In the second technique, a hydrogen pellet will be formed, loaded into a miniature rifle, and accelerated by means of high pressure hydrogen gas. This technique should be capable of speeds of the order of 1000 m/sec. While this technique does not offer the high performance of the mechanical accelerator, its relative simplicity makes it attractive for near-term experiments

  6. Accelerator development at Bates

    International Nuclear Information System (INIS)

    Sargent, C.P.

    1983-01-01

    The past year has seen the completion of a major expansion of the Bates Accelerator Laboratory. A second experimental hall, South Hall, and several magnetic spectrometers have been constructed. The accelerator's maximum energy has been raised from 400 to 750 MeV by means of beam recirculation. A current two-year project for the fabrication of an additional RF transmitter plus a 30% increase in RF peak power capability will increase energy further to ca. 1 GeV. During the same period pulse-to-pulse beam sharing between the high-resolution spectrometer area and South Hall will become available. In January 1981 the Laboratory submitted their ''Proposal for a Long-Range Expansion Program'' to DOE-NSF. The proposed development consists of three stages. Stage I calls for the addition of a pulse stretcher ring to furnish a CW beam to the South Hall beam lines. Additional experimental space for internal target experiments and photon tagging research are also included. Stage II increases the accelerator energy to 2.1 GeV (at 140 microamps) by means of a five-pass head-to-tail recirculator. Stage III is, at this time, a plan rather than a proposal. It increases accelerator energy to 4 GeV by extending the accelerator length and power and adds another pulse stretcher ring and three new experimental areas for the higher energy work. This paper discusses each of these stages in detail and recommends their funding and scheduling

  7. High energy plasma accelerators

    International Nuclear Information System (INIS)

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ω 0 , kappa 0 and ω 1 , kappa 1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 10 18 cm -3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  8. Linear induction accelerators

    International Nuclear Information System (INIS)

    Briggs, R.J.

    1986-06-01

    The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs

  9. Automatic annotation of head velocity and acceleration in Anvil

    DEFF Research Database (Denmark)

    Jongejan, Bart

    2012-01-01

    We describe an automatic face tracker plugin for the ANVIL annotation tool. The face tracker produces data for velocity and for acceleration in two dimensions. We compare the annotations generated by the face tracking algorithm with independently made manual annotations for head movements....... The annotations are a useful supplement to manual annotations and may help human annotators to quickly and reliably determine onset of head movements and to suggest which kind of head movement is taking place....

  10. Accelerators for atomic energy research

    International Nuclear Information System (INIS)

    Shibata, Tokushi

    1999-01-01

    The research and educational activities accomplished using accelerators for atomic energy research were studied. The studied items are research subjects, facility operation, the number of master theses and doctor theses on atomic energy research using accelerators and the future role of accelerators in atomic energy research. The strategy for promotion of the accelerator facility for atomic energy research is discussed. (author)

  11. Accelerators in Science and Technology

    CERN Document Server

    Kailas, S

    2002-01-01

    Accelerators built for basic research in frontier areas of science have become important and inevitable tools in many areas of science and technology. Accelerators are examples of science driven high technology development. Accelerators are used for a wide ranging applications, besides basic research. Accelerator based multidisciplinary research holds great promise

  12. Plasma-based accelerator structures

    International Nuclear Information System (INIS)

    Schroeder, Carl B.

    1999-01-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas

  13. Microstructure of rapidly solidified materials

    Science.gov (United States)

    Jones, H.

    1984-07-01

    The basic features of rapidly solidified microstructures are described and differences arising from alternative processing strategies are discussed. The possibility of achieving substantial undercooling prior to solidification in processes such as quench atomization and chill block melt spinning can give rise to striking microstructural transitions even when external heat extraction is nominally Newtonian. The increased opportunity in laser and electron beam surface melting for epitaxial growth on the parent solid at an accelerating rate, however, does not exclude the formation of nonequilibrium phases since the required undercooling can be locally attained at the solidification front which is itself advancing at a sufficiently high velocity. The effects of fluid flow indicated particularly in melt spinning and surface melting are additional to the transformational and heat flow considerations that form the present basis for interpretation of such microstructural effects.

  14. Application of powerful quasi-steady-state plasma accelerators for simulation of ITER transient heat loads on divertor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tereshin, V I [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Bandura, A N [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Byrka, O V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Chebotarev, V V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Garkusha, I E [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Landman, I [Forschungszentrum Karlsruhe, IHM, Karlsruhe 76021 (Germany); Makhlaj, V A [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Neklyudov, I M [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Solyakov, D G [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Tsarenko, A V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine)

    2007-05-15

    The paper presents the investigations of high power plasma interaction with material surfaces under conditions simulating the ITER disruptions and type I ELMs. Different materials were exposed to plasma with repetitive pulses of 250 {mu}s duration, the ion energy of up to 0.6 keV, and the heat loads varying in the 0.5-25 MJ m{sup -2} range. The plasma energy transfer to the material surface versus impact load has been analysed. The fraction of plasma energy that is absorbed by the target surface is rapidly decreased with the achievement of the evaporation onset for exposed targets. The distributions of evaporated material in front of the target surface and the thickness of the shielding layer are found to be strongly dependent on the target atomic mass. The surface analysis of tungsten targets exposed to quasi-steady-state plasma accelerators plasma streams is presented together with measurements of the melting onset load and evaporation threshold, and also of erosion patterns with increasing heat load and the number of plasma pulses.

  15. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  16. Need for accelerating electrons

    International Nuclear Information System (INIS)

    Kerst, D.W.

    1987-01-01

    Photons for nuclear disintegration experiments were not abundantly available in the early days of nuclear physics, whereas accelerated ions led the way. When electrons could be accelerated into the 20--30 MeV range, they found application not only to nuclear disintegration of the elements of the periodic table but also to x-ray radiography and to deep therapy. Energies of interest for probing nuclear structure by electron scattering and for meson production followed soon after. The elementary nature of the electron has now made it a valuable tool for present day particle physics; and the synchrotron radiation, which is an obstacle for some accelerating processes, has become a much sought after source of photons for experiments at atomic structure energies

  17. Artificial seismic acceleration

    Science.gov (United States)

    Felzer, Karen R.; Page, Morgan T.; Michael, Andrew J.

    2015-01-01

    In their 2013 paper, Bouchon, Durand, Marsan, Karabulut, 3 and Schmittbuhl (BDMKS) claim to see significant accelerating seismicity before M 6.5 interplate mainshocks, but not before intraplate mainshocks, reflecting a preparatory process before large events. We concur with the finding of BDMKS that their interplate dataset has significantly more fore- shocks than their intraplate dataset; however, we disagree that the foreshocks are predictive of large events in particular. Acceleration in stacked foreshock sequences has been seen before and has been explained by the cascade model, in which earthquakes occasionally trigger aftershocks larger than themselves4. In this model, the time lags between the smaller mainshocks and larger aftershocks follow the inverse power law common to all aftershock sequences, creating an apparent acceleration when stacked (see Supplementary Information).

  18. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  19. Incineration by accelerator

    International Nuclear Information System (INIS)

    Cribier, M.; FIoni, G.; Legrain, R.; Lelievre, F.; Leray, S.; Pluquet, A.; Safa, H.; Spiro, M.; Terrien, Y.; Veyssiere, Ch.

    1997-01-01

    The use MOX fuel allows to hope a stabilization of plutonium production around 500 tons for the French park. In return, the flow of minor actinides is increased to several tons. INCA (INCineration by Accelerator), dedicated instrument, would allow to transmute several tons of americium, curium and neptunium. It could be able to reduce nuclear waste in the case of stopping nuclear energy use. This project needs: a protons accelerator of 1 GeV at high intensity ( 50 m A), a window separating the accelerator vacuum from the reactor, a spallation target able to produce 30 neutrons by incident proton, an incineration volume where a part of fast neutrons around the target are recovered, and a thermal part in periphery with flows at 2.10 15 n/cm 2 .s; a chemical separation of elements burning in thermal (americium) from the elements needing a flow of fast neutrons. (N.C.)

  20. Universality of accelerating change

    Science.gov (United States)

    Eliazar, Iddo; Shlesinger, Michael F.

    2018-03-01

    On large time scales the progress of human technology follows an exponential growth trend that is termed accelerating change. The exponential growth trend is commonly considered to be the amalgamated effect of consecutive technology revolutions - where the progress carried in by each technology revolution follows an S-curve, and where the aging of each technology revolution drives humanity to push for the next technology revolution. Thus, as a collective, mankind is the 'intelligent designer' of accelerating change. In this paper we establish that the exponential growth trend - and only this trend - emerges universally, on large time scales, from systems that combine together two elements: randomness and amalgamation. Hence, the universal generation of accelerating change can be attained by systems with no 'intelligent designer'.

  1. Future accelerators in Japan

    International Nuclear Information System (INIS)

    Toge, Nobu

    1993-01-01

    This paper presents a brief report on the present status of future accelerator projects at the National Laboratory for High Energy Physics (KEK), Japan. The KEK laboratory has been successfully operating the TRISTAN accelerator complex since 1986. It consists of a 2.5 GeV electron/positron linac, an 8 GeV Accumulation Ring (AR) and a 29 GeV Main Ring (MR). Concurrently with this operation, in response to recommendations by the Japanese High Energy Physics Committee, survey studies have been continued on new accelerator facilities at KEK. They have two major future projects, namely, the asymmetric e + e - B-factory based on TRISTAN (TRISTAN-II) and the Japan Linear Collider (JLC). The purpose of this paper is to outline those research activities and to present an update on their status

  2. Medical uses of accelerators

    International Nuclear Information System (INIS)

    Bradbury, J.N.

    1981-01-01

    A variety of particle accelerators have either potential or already demonstrated uses in connection with medically-related research, diagnosis, and treatment. For cancer radiotherapy, nuclear particles including protons, neutrons, heavy ions, and negative pi mesons have advantages compared to conventional radiations in terms of dose localization and/or biological effectiveness. Clinical evaluations of these particles are underway at a number of institutions. Accelerator-produced radionuclides are in widespread use for research and routine diagnostic purposes. Elemental analysis techniques with charged particles and neutrons are being applied to bone, blood, and other tissues. Finally, low-dose medical imaging can be accomplished with accelerated protons and heavy ions. The status and future of these programs are discussed

  3. JKJ accelerator timing system

    International Nuclear Information System (INIS)

    Ohmori, C.; Mori, Y.; Yoshii, M.; Yamamoto, M.

    2001-01-01

    The JKJ (JAERl-KEK Joint Project) accelerator complex consists of the linear accelerator, 3 GeV and 50 GeV synchrotrons. To minimize the beam loss during the beam transfer from the 3 GeV synchrotron to the 50 GeV one, the synchronization of the two RF system of the rings is very important. To reduce the background from the high and low momentum neutron, the neutron beam chopper will be employed. The 3 GeV RF will be also synchronized to the chopper timing when the beam goes to the neutron facility. The whole timing control system of these accelerators and chopper will be described. (author)

  4. Accelerators for therapy

    International Nuclear Information System (INIS)

    Pohlit, W.

    1994-01-01

    In the past decades circular and linear electron accelerators have been developed for clinical use in radiation therapy of tumors with the aim of achieving a high radiation dose in the tumor and as low as possible dose in the adjacent normal tissues. Today about one thousand accelerators are in medical use throughout the world and many hundred thousand patients are treated every day with accelerator-produced radiation. There exists, however, a large number of patients who cannot be treated satisfactorily in this way. New types of radiations such as neutrons, negative pions, protons and heavy ions were therefore tested recently. The clinical experience with these radiations and with new types of treatment procedures indicate that in future the use of a scanning beam of high energy protons might be optimal for the treatment of tumors. (orig.)

  5. Superconducting accelerator magnet design

    International Nuclear Information System (INIS)

    Wolff, S.

    1994-01-01

    Superconducting dipoles, quadrupoles and correction magnets are necessary to achieve the high magnetic fields required for big accelerators presently in construction or in the design phase. Different designs of superconducting accelerator magnets are described and the designs chosen at the big accelerator laboratories are presented. The most frequently used cosθ coil configuration is discussed in detail. Approaches for calculating the magnetic field quality including coil end fields are presented. Design details of the cables, coils, mechanical structures, yokes, helium vessels and cryostats including thermal radiation shields and support structures used in superconducting magnets are given. Necessary material properties are mentioned. Finally, the main results of magnetic field measurements and quench statistics are presented. (orig.)

  6. Accelerator technology in tokamaks

    International Nuclear Information System (INIS)

    Kustom, R.L.

    1977-01-01

    This article presents the similarities in the technology required for high energy accelerators and tokamak fusion devices. The tokamak devices and R and D programs described in the text represent only a fraction of the total fusion program. The technological barriers to producing successful, economical tokamak fusion power plants are as many as the plasma physics problems to be overcome. With the present emphasis on energy problems in this country and elsewhere, it is very likely that fusion technology related R and D programs will vigorously continue; and since high energy accelerator technology has so much in common with fusion technology, more scientists from the accelerator community are likely to be attracted to fusion problems

  7. Accelerating the culture change!

    Science.gov (United States)

    Klunk, S W; Panetta, J; Wooten, J

    1996-11-01

    Exide Electronics, a major supplier of uninterruptible power system equipment, embarked on a journey of changing a culture to improve quality, enhance customer responsiveness, and reduce costs. This case study examines the evolution of change over a period of seven years, with particular emphasis on the most recent years, 1992 through 1995. The article focuses on the Raleigh plant operations and describes how each succeeding year built on the successes and fixed the shortcomings of the prior years to accelerate the culture change, including corrective action and continuous improvement processes, organizational structures, expectations, goals, achievements, and pitfalls. The real challenge to changing the culture was structuring a dynamic approach to accelerate change! The presentation also examines how the evolutionary process itself can be created and accelerated through ongoing communication, regular feedback of progress and goals, constant evaluation and direction of the process, and measuring and paying for performance.

  8. Studies of accelerated compact toruses

    International Nuclear Information System (INIS)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.

    1983-01-01

    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  9. Microelectromechanical acceleration-sensing apparatus

    Science.gov (United States)

    Lee, Robb M [Albuquerque, NM; Shul, Randy J [Albuquerque, NM; Polosky, Marc A [Albuquerque, NM; Hoke, Darren A [Albuquerque, NM; Vernon, George E [Rio Rancho, NM

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  10. CERN: Accelerator school

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Full text: Jyvaskyla, a university town in central Finland, was the setting for last year's General Accelerator School organized by the CERN Accelerator School. Well over a hundred students - more than for some time - followed two weeks of lectures on a broad spectrum of accelerator topics, the first step en route to becoming the designers, builders and operators of the surprisingly large number of, accelerators of all kinds either built or planned throughout Europe and further afield. This was the fifth such school organized by CAS in a biennial cycle which alternates this introductory level with more advanced tuition. The next, advanced, school will be from 20 October - 1 November, hosted by Athens University on the Greek Island of Rhodes. (Application details will become available in Spring but would-be participants should already reserve the dates.) After Finland, the CAS caravan moved to Benalmadena near Malaga in Spain where, together with Seville University, they organized one of the joint US-CERN schools held every two years and focusing on frontier accelerator topics. This time the subject was electron-positron factories - machines for high luminosity experiments in phi, tau-charm, beauty and Z physics. Experts from both sides of the Atlantic and from Japan shared their knowledge with an equally representative audience and probed the many intensity related phenomena which must be mastered to reach design performance. A number of these topics will receive extended coverage in the next specialist CAS School which is a repeat - by public demand - of the highly successful radiofrequency course held in Oxford in 1991. This school will be in Capri, Italy, with the support of the University of Naples from 29 April to 5 May. Details and application forms are now available by e-mail (CASRF@CERNVM.CERN.CH), by fax (+41 22 7824836) or from Suzanne von Wartburg, CERN Accelerator School, 1211 Geneva 23, Switzerland

  11. Interfacing to accelerator instrumentation

    International Nuclear Information System (INIS)

    Shea, T.J.

    1995-01-01

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed

  12. Acceleration of polarized particles

    International Nuclear Information System (INIS)

    Buon, J.

    1992-05-01

    The spin kinetics of polarized beams in circular accelerators is reviewed in the case of spin-1/2 particles (electrons and protons) with emphasis on the depolarization phenomena. The acceleration of polarized proton beams in synchrotrons is described together with the cures applied to reduce depolarization, including the use of 'Siberian Snakes'. The in-situ polarization of electrons in storage rings due to synchrotron radiation is studied as well as depolarization in presence of ring imperfections. The applications of electron polarization to accurately calibrate the rings in energy and to use polarized beams in colliding-beam experiments are reviewed. (author) 76 refs., 19 figs., 1 tab

  13. Spallator - accelerator breeder

    International Nuclear Information System (INIS)

    Steinberg, M.

    1985-01-01

    The concept involves the use of spallation neutrons produced by interaction of a high energy proton (1 to 2 GeV) from a linear accelerator (LINAC) with a heavy metal target (uranium). The principal spallator concept is based on generating fissile fuel for use in LWR nuclear power plants. The spallator functions in conjunction with a reprocessing plant to regenerate and produce the Pu-239 or U-233 for fabrication into fresh LWR reactor fuel elements. Advances in proton accelerator technology has provided a solid base for predicting performance and optimizing the design of a reliable, continuous wave, high-current LINAC required by a fissile fuel production machine

  14. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  15. Electrostatic accelerator dielectrics

    International Nuclear Information System (INIS)

    Cooke, C.M.

    1989-05-01

    High voltage insulation problems in electrostatic accelerators are discussed. The aim of the analysis is to broaden the knowledge, highlight the characteristics of insulation technology and design strategies to improve use. The basic geometry of the insulation in accelerators is considered. A detailed description of each of the insulation regions is provided. The gas gap insulation of the terminal voltage is found to be sensitive to regions of high electric stress. In order to obtain satisfactory performance from solid support insulation, the attention is focused on the electric stress value and distribution. Potential subjects for discussion and further investigations are given

  16. Remarks on stochastic acceleration

    International Nuclear Information System (INIS)

    Graeff, P.

    1982-12-01

    Stochastic acceleration and turbulent diffusion are strong turbulence problems since no expansion parameter exists. Hence the problem of finding rigorous results is of major interest both for checking approximations and for reference models. Since we have found a way of constructing such models in the turbulent diffusion case the question of the extension to stochastic acceleration now arises. The paper offers some possibilities illustrated by the case of 'stochastic free fall' which may be particularly interesting in the context of linear response theory. (orig.)

  17. Monoenergetic laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    N. E. Andreev

    2000-02-01

    Full Text Available Three dimensional test particle simulations are applied to optimization of the plasma-channeled laser wakefield accelerator (LWFA operating in a weakly nonlinear regime. Electron beam energy spread, emittance, and luminosity depend upon the proportion of the electron bunch size to the plasma wavelength. This proportion tends to improve with the laser wavelength increase. We simulate a prospective two-stage ∼1GeV LWFA with controlled energy spread and emittance. The input parameters correspond to realistic capabilities of the BNL Accelerator Test Facility that features a picosecond-terawatt CO_{2} laser and a high-brightness electron gun.

  18. High intensity hadron accelerators

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics

  19. Photocathodes in accelerator applications

    International Nuclear Information System (INIS)

    Fraser, J.S.; Sheffield, R.L.; Gray, E.R.; Giles, P.M.; Springer, R.W.; Loebs, V.A.

    1987-01-01

    Some electron accelerator applications require bursts of short pulses at high microscopic repetition rates and high peak brightness. A photocathode, illuminated by a mode-locked laser, is well suited to filling this need. The intrinsic brightness of a photoemitter beam is high; experiments are under way at Los Alamos to study the brightness of short bunches with high space charge after acceleration. A laser-illuminated Cs 3 Sb photoemitter is located in the first rf cavity of an injector linac. Diagnostics include a pepper-pot emittance analyzer, a magnetic spectrometer, and a streak camera

  20. "Light sail" acceleration reexamined.

    Science.gov (United States)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  1. 'Light Sail' Acceleration Reexamined

    International Nuclear Information System (INIS)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-01-01

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  2. Accelerating time to benefit

    DEFF Research Database (Denmark)

    Svejvig, Per; Geraldi, Joana; Grex, Sara

    Despite the ubiquitous pressure for speed, our approaches to accelerate projects remain constrained to the old-fashioned understanding of the project as a vehicle to deliver products and services, not value. This article explores an attempt to accelerate time to benefit. We describe and deconstruct...... of the time. Although all cases valued speed and speed to benefit, and implemented most practices proposed by the methodology, only three of the five projects were more successful in decreasing time to speed. Based on a multi-case study comparison between these five different projects and their respective...

  3. Plasma wave accelerator. II

    International Nuclear Information System (INIS)

    Mori, W.; Joshi, C.; Dawson, J.M.

    1982-01-01

    It was shown that the insertion of a cross magnetic field prevents the particles from getting out of phase with the electric field of the plasma wave in the beat wave accelerator scheme. Thus, using a CO 2 laser, n/sub c//n/sub e/ = (ω 0 /ω/sub p/) 2 approx. 35, and a 300 kG magnetic field, electrons can be (in principle) accelerated to 100 GeV in 2 meters. For comparison without the magnetic field, the same energies may be obtained in a n/sub c//n/sub e/ approx. 10 5 plasma over a distance of 100 meters

  4. An accelerator technology legacy

    International Nuclear Information System (INIS)

    Heighway, E.A.

    1994-01-01

    Accelerator technology has been a major beneficiary of the investment made over the last decade. It is the intention of this paper to provide the reader with a glimpse of the broad nature of those advances. Development has been on a broad front and this paper can highlight only a few of those. Two spin-off applications will be outlined -- a concept for a compact, active, beam probe for solar body exploration and the concept for an accelerator-driven transmutation system for energy production

  5. The neuropsychology and neurobiology of late-onset schizophrenia and very-late-onset schizophrenia-like psychosis: A critical review.

    Science.gov (United States)

    Van Assche, Lies; Morrens, Manuel; Luyten, Patrick; Van de Ven, Luc; Vandenbulcke, Mathieu

    2017-12-01

    The current review discusses neuropsychological profiles and the longitudinal course of cognitive dysfunction in Late Onset Schizophrenia (LOS) and Very-late-onset schizophrenia-like psychosis (VLOSLP), and attempts to clarify its neurobiological underpinnings. A systematic literature search resulted in 29 publications describing original research on the neuropsychology of LOS/VLOSLP and 46 studies focussing on neurobiology. Although mildly progressive cognitive impairment is usually present, only a subgroup of LOS/VLOSLP develops dementia during a 10-year follow-up succeeding the onset of psychosis. This coincides with the absence of neuropathological evidence for neurodegeneration in many cases. Cognitive deterioration is characterized by deficits in (working) memory, language, psychomotor speed and executive functioning. Underlying neurobiological changes encompass white matter pathology, increased ventricle-to-brain ratio (VBR) with coinciding atrophy and hypo-metabolism of frontal, temporal and subcortical areas. Multiple changes in neurobiology and cognition contributing to LOS/VLOSLP may reflect stress-related accelerated brain aging rather than neurodegenerative pathology. Their involvement in the onset of illness, however, might be inversely proportional to pre-existing (psychosocial and/or genetic) vulnerability to psychosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Quantitative estimation on delaying of onset of corrosion of rebar in surface treated concrete using sealers

    Directory of Open Access Journals (Sweden)

    A. Sivasankar

    2013-12-01

    Full Text Available Surface treatment on the concrete surface using sealers reduces the rate of permeability of chloride and moisture through the concrete. The delaying of onset of corrosion is evaluated for surface treated and untreated concrete using electrochemical techniques. After conducting rapid chloride permeability test (RCPT, using Nernst–Plank equation, the diffusion coefficient of chloride (Deff is calculated. Substituting threshold chloride concentration of rebar (Cth from cyclic polarization test in the ficks second law, the time to initiation of corrosion (Ti is arrived. From the results it is found that the treated concrete with alkyltrialkoxy silane sealer delays the onset of corrosion by four times than that of untreated concrete.

  7. A Statistical Perspective on Highly Accelerated Testing

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Edward V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    Highly accelerated life testing has been heavily promoted at Sandia (and elsewhere) as a means to rapidly identify product weaknesses caused by flaws in the product's design or manufacturing process. During product development, a small number of units are forced to fail at high stress. The failed units are then examined to determine the root causes of failure. The identification of the root causes of product failures exposed by highly accelerated life testing can instigate changes to the product's design and/or manufacturing process that result in a product with increased reliability. It is widely viewed that this qualitative use of highly accelerated life testing (often associated with the acronym HALT) can be useful. However, highly accelerated life testing has also been proposed as a quantitative means for "demonstrating" the reliability of a product where unreliability is associated with loss of margin via an identified and dominating failure mechanism. It is assumed that the dominant failure mechanism can be accelerated by changing the level of a stress factor that is assumed to be related to the dominant failure mode. In extreme cases, a minimal number of units (often from a pre-production lot) are subjected to a single highly accelerated stress relative to normal use. If no (or, sufficiently few) units fail at this high stress level, some might claim that a certain level of reliability has been demonstrated (relative to normal use conditions). Underlying this claim are assumptions regarding the level of knowledge associated with the relationship between the stress level and the probability of failure. The primary purpose of this document is to discuss (from a statistical perspective) the efficacy of using accelerated life testing protocols (and, in particular, "highly accelerated" protocols) to make quantitative inferences concerning the performance of a product (e.g., reliability) when in fact there is lack-of-knowledge and uncertainty concerning

  8. Applications of High Intensity Proton Accelerators

    Science.gov (United States)

    Raja, Rajendran; Mishra, Shekhar

    2010-06-01

    Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon

  9. Feedback between Accelerator Physicists and magnet builders

    International Nuclear Information System (INIS)

    Peggs, S.

    1995-01-01

    Our task is not to record history but to change it. (K. Marx (paraphrased)) How should Accelerator Physicists set magnet error specifications? In a crude social model, they place tolerance limits on undesirable nonlinearities and errors (higher order harmonics, component alignments, etc.). The Magnet Division then goes away for a suitably lengthy period of time, and comes back with a working magnet prototype that is reproduced in industry. A better solution is to set no specifications. Accelerator Physicists begin by evaluating expected values of harmonics, generated by the Magnet Division, before and during prototype construction. Damaging harmonics are traded off against innocuous harmonics as the prototype design evolves, lagging one generation behind the evolution of expected harmonics. Finally, the real harmonics are quickly evaluated during early industrial production, allowing a final round of performance trade-offs, using contingency scenarios prepared earlier. This solution assumes a close relationship and rapid feedback between the Accelerator Physicists and the magnet builders. What follows is one perspective of the way that rapid feedback was used to 'change history' (improve linear and dynamic aperture) at RHIC, to great benefit

  10. Materials considerations in accelerator targets

    International Nuclear Information System (INIS)

    Peacock, H. B. Jr.; Iyer, N. C.; Louthan, M. R. Jr.

    1995-01-01

    Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from, the coextruded product was modeled from experimental and operational data. The model assumed that tritium atoms, formed by the 6Li(n,a)3He reaction, were produced in solid solution in the Al-Li alloy. Because of the low solubility of hydrogen isotopes in aluminum alloys, the irradiated Al-Li rapidly became supersaturated in tritium. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes

  11. Inherited leukoencephalopathies with clinical onset in middle and old age.

    Science.gov (United States)

    Nannucci, Serena; Donnini, Ida; Pantoni, Leonardo

    2014-12-15

    The currently widespread use of neuroimaging has led neurologists to often face the problem of the differential diagnosis of white matter diseases. There are various forms of leukoencephalopathies (vascular, inflammatory and immunomediated, infectious, metabolic, neoplastic) and sometimes white matter lesions are expression of a genetic disease. While many inherited leukoencephalopathies fall in the child neurologist's interest, others may have a delayed or even a typical onset in the middle or old age. This field is rapidly growing and, in the last few years, many new inherited white matter diseases have been described and genetically defined. A non-delayed recognition of middle and old age inherited leukoencephalopathies appears important to avoid unnecessary tests and therapies in the patient and to possibly anticipate the diagnosis in relatives. The aim of this review is to provide a guide to direct the diagnostic process when facing a patient with a suspicion of an inherited form of leukoencephalopathy and with clinical onset in middle or old age. Based on a MEDLINE search from 1990 to 2013, we identified 24 middle and old age onset inherited leukoencephalopathies and reviewed in this relation the most recent findings focusing on their differential diagnosis. We provide summary tables to use as a check list of clinical and neuroimaging findings that are most commonly associated with these forms of leukoencephalopathies. When present, we reported specific characteristics of single diseases. Several genetic diseases may be suspected in patients with middle or old age and white matter abnormalities. In only few instances, pathognomonic clinical or associated neuroimaging features help identifying a specific disease. Therefore, a comprehensive knowledge of the characteristics of these inherited white matter diseases appears important to improve the diagnostic work-up, optimize the choice of genetic tests, increase the number of diagnosed patients, and stimulate

  12. Accelerators in the sky

    International Nuclear Information System (INIS)

    Setti, G.

    1977-01-01

    The author surveys the large body of evidence showing that there are very efficient mechanisms capable of accelerating particles to high energies under very different astrophysical conditions. The circumstances whereby huge amounts of relativistic and ultrarelativistic particles such as one finds in a) cosmic rays, b) supernova remnants and c) radio galaxies and quasars are produced are considered. (Auth.)

  13. Heavy ion accelerator GANIL

    International Nuclear Information System (INIS)

    1975-04-01

    This article presents GANIL, a large national heavy ion accelerator. The broad problems of nuclear physics, atomic physics, astrophysics and physics of condensed media which can be approached and studied with this machine are discussed first, after which the final construction project is described. The project comprises a circular injector, a separated sector cyclotron up beam stripper, and a second separated cyclotron downstream [fr

  14. Accelerating with industry

    International Nuclear Information System (INIS)

    Southworth, Brian

    1992-01-01

    At the end of March, Berlin was the scene of the third biennial European Particle Accelerator Conference (EPAC). It carried the usual news from the front-line machines in the high energy physics Laboratories and reports on progress with the latest technologies

  15. Two-beam accelerator

    International Nuclear Information System (INIS)

    Sessler, A.M.; Hopkins, D.B.

    1986-06-01

    The Two-Beam Accelerator (TBA) consists of a long high-gradient accelerator structure (HGS) adjacent to an equal-length Free Electron Laser (FEL). In the FEL, a beam propagates through a long series of undulators. At regular intervals, waveguides couple microwave power out of the FEL into the HGS. To replenish energy given up by the FEL beam to the microwave field, induction accelerator units are placed periodically along the length of the FEL. In this manner it is expected to achieve gradients of more than 250 MV/m and thus have a serious option for a 1 TeV x 1 TeV linear collider. The state of present theoretical understanding of the TBA is presented with particular emphasis upon operation of the ''steady-state'' FEL, phase and amplitude control of the rf wave, and suppression of sideband instabilities. Experimental work has focused upon the development of a suitable HGS and the testing of this structure using the Electron Laser Facility (ELF). Description is given of a first test at ELF with a seven-cell 2π/3 mode structure which without preconditioning and with a not-very-good vacuum nevertheless at 35 GHz yielded an average accelerating gradient of 180 MV/m

  16. Hamburg Accelerator Conference

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Edmund J.N. [CERN Accelerator School (Switzerland)

    1992-10-15

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). A natural highlight was the recent commissioning success of the HERA electron-proton collider at Hamburg's DESY Laboratory and its first high energy electron-proton collision data. This gave the meeting the feel of a family event celebrating a newborn.

  17. The Bevalac accelerator

    International Nuclear Information System (INIS)

    Dacal, A.

    1989-01-01

    Presented are the characteristics of the Bevatron and SuperHilac heavy ion accelerators in a very general manner. Some aspects of their application in the field of biological medicine and some of the interesting results obtained in experiments on nuclear physics are mentioned. (Author). 20 refs, 2 figs, 2 tabs

  18. Radioisotope Dating with Accelerators.

    Science.gov (United States)

    Muller, Richard A.

    1979-01-01

    Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)

  19. The CERN accelerator complex

    CERN Multimedia

    Mobs, Esma Anais

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  20. The CERN accelerator complex

    CERN Multimedia

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  1. Prospects for Accelerator Technology

    Science.gov (United States)

    Todd, Alan

    2011-02-01

    Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

  2. Ion sources for accelerators

    International Nuclear Information System (INIS)

    Alton, G.D.

    1974-01-01

    A limited review of low charge sate positive and negative ion sources suitable for accelerator use is given. A brief discussion is also given of the concepts underlying the formation and extraction of ion beams. Particular emphasis is placed on the technology of ion sources which use solid elemental or molecular compounds to produce vapor for the ionization process

  3. BNL accelerator plans

    International Nuclear Information System (INIS)

    Lowenstein, D.I.

    1986-01-01

    The Brookhaven National Laboratory plan for high energy and heavy ion physics accelerator use for the next ten-year period is described. The two major initiatives are in the construction of the Relativistic Heavy Ion Collider and the upgrade of the Alternating Gradient Synchrotron to a ''Mini Kaon Factory''

  4. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics This course will take place in Budapest, Hungary, from 2 to 14 October 2016. It is now open for registration and further information can be found at: http://cas.web.cern.ch/cas/Hungary2016/Hungary-advert.html and http://indico.cern.ch/event/532397/.

  5. Accelerating with industry

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Brian

    1992-06-15

    At the end of March, Berlin was the scene of the third biennial European Particle Accelerator Conference (EPAC). It carried the usual news from the front-line machines in the high energy physics Laboratories and reports on progress with the latest technologies.

  6. Accelerating News Issue 5

    CERN Document Server

    Szeberenyi, A

    2013-01-01

    In this spring issue, we look at developments towards higher luminosity and higher energy colliders. We report on the technology developed for the remote powering of the LHC magnets and studies of diagnostics based on higher order mode port signals. We also inform you about the main outcome of the TIARA survey on market needs for accelerator scientists.

  7. Next generation of accelerators

    International Nuclear Information System (INIS)

    Richter, B.

    1979-01-01

    Existing high-energy accelerators are reviewed, along with those under construction or being designed. Finally, some of the physics issues which go into setting machine parameters, and some of the features of the design of next generation electron and proton machines are discussed

  8. Cockroft Walton accelerator prototype

    International Nuclear Information System (INIS)

    Hutapea, Sumihar.

    1976-01-01

    Prototype of a Cockroft Walton generator using ceramic and plastic capacitors is discussed. Compared to the previous generator, the construction and components are much more improved. Pralon is used for the high voltage insulation column and plastic is used as a dielectric material for the high voltage capacitor. Cockroft Walton generator is used as a high tension supply for an accelerator. (author)

  9. Accelerated product development

    NARCIS (Netherlands)

    Langerak, F.; Seth, J.N.; Malhotra, N.K.

    2011-01-01

    Accelerated product development is a competitive strategy that seeks to reduce the development cycle time of new products. However, there has been little theoretical advancement and empirical model testing in the identification of the conditions under which cycle time reduction is appropriate, the

  10. The ATOMKI Accelerator Center

    International Nuclear Information System (INIS)

    Biri, S.; Kormany, Z.; Berzi, I.; Hunyadi, M.

    2009-01-01

    In 2009 a new division was established in our institute: the ATOMKI Accelerator Center (AAC). Before this time the facilities and staff of AAC belonged to other departments of the institute. The re-organization however, was necessary. It was understood that the translocation of all the accelerators into a centralized unit is advantageous in numerous fields. Here we just mention some of them. The submission of any instrumentation type proposal (EU or domestic) will be easier and has a higher chance to be supported. The organization and distribution of the beamtimes will be more equal and optimal. The usage of the maintenance and spare tools can became better and cheaper. The operating staff (cca. 20 person) can serve at more than one accelerator and the teams can help each other. The accelerator center actually became a fourth new basic unit of the institute besides the three traditional scientific divisions (see the Atomki homepage for the organization chart). The following six main facilities belong to the accelerator center: Cyclotron; VdG-5 accelerator; VdG-1 accelerator; ECR ion source; Isotope separator; Tandetron (under installation). In figure 1 the placements of these machines are shown in an artistic 3D map of the Atomki. The table 1 summarizes the main parameters of the accelerators. More detailed technical specification of the machines can be found in the new homepage of the center. In 2009 all the accelerators operated as scheduled, safely and without major breakdowns. After the experiences in the first months it can be concluded that the new center works well both for technical and human point of views. In the next sub-chapters the 2009 operation and development details of the individual accelerators are summarized. Cyclotron operation. The operation of the cyclotron in 2009 was concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 2009 hours; the time

  11. Wakeless triple soliton accelerator

    International Nuclear Information System (INIS)

    Mima, K.; Ohsuga, T.; Takabe, H.; Nishihara, K.; Tajima, T.; Zaidman, E.; Horton, W.

    1986-09-01

    We introduce and analyze the concept of a wakeless triple soliton accelerator in a plasma fiber. Under appropriate conditions the triple soliton with two electromagnetic and one electrostatic waves in the beat-wave resonance propagates with velocity c leaving no plasma wake behind, while the phase velocity of the electrostatic wave is made also c in the fiber

  12. Hamburg Accelerator Conference

    International Nuclear Information System (INIS)

    Wilson, Edmund J.N.

    1992-01-01

    From 20-24 July, Hamburg welcomed the Fifteenth International Conference on High Energy Accelerators (HEACC). A natural highlight was the recent commissioning success of the HERA electron-proton collider at Hamburg's DESY Laboratory and its first high energy electron-proton collision data. This gave the meeting the feel of a family event celebrating a newborn

  13. The CERN accelerator complex

    CERN Multimedia

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  14. Onset of autumn shapes the timing of birth in Pyrenean chamois more than onset of spring.

    Science.gov (United States)

    Kourkgy, Charlotte; Garel, Mathieu; Appolinaire, Joël; Loison, Anne; Toïgo, Carole

    2016-03-01

    In seasonal environments, birth dates are a central component for a species' life history, with potential long-term fitness consequences. Yet our understanding of selective pressures of environmental changes on birth dates is limited in wild mammals due to the difficulty of data collection. In a context of rapid climate change, the question of a possible mismatch between plant phenology and birth phenology also remains unanswered for most species. We assessed whether and how the timing of birth in a mountain mammal (isard, also named Pyrenean chamois, Rupicapra pyrenaica pyrenaica) tracked changes in plant growing season, accounting for maternal traits, individual heterogeneity and population density. We not only focused on spring conditions but also assessed to what extent onset of autumn can be a driver of phenological biological events and compared the magnitude of the response to the magnitude of the environmental changes. We relied on a 22-year study based on intensively monitored marked individuals of known age. Births were highly synchronized (80% of kids born within 25 days) and highly repeatable (84%; between-female variation of 9.6 days, within-female variation of 4.2 days). Individual phenotypic plasticity allows females to respond rapidly to interannual changes in plant phenology but did not prevent the existence of a mismatch: a 10-day advance in the autumn or spring plant phenology led to 3.9 and 1.3 days advance in birth dates, respectively. Our findings suggest that plant phenology may act as a cue to induce important stages of the reproductive cycle (e.g. conception and gestation length), subsequently affecting parturition dates, and stressed the importance of focusing on long-term changes during spring for which females may show much lower adaptive potential than during autumn. These results also question the extent to which individual plasticity along with high heterogeneity among individuals will allow species to cope with demographic

  15. Relativity and accelerator engineering

    International Nuclear Information System (INIS)

    Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

    2017-09-01

    From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 μm. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather ''practical'', and should be acceptable to accelerator physicists.

  16. Menopause accelerates biological aging

    Science.gov (United States)

    Levine, Morgan E.; Lu, Ake T.; Chen, Brian H.; Hernandez, Dena G.; Singleton, Andrew B.; Ferrucci, Luigi; Bandinelli, Stefania; Salfati, Elias; Manson, JoAnn E.; Quach, Austin; Kusters, Cynthia D. J.; Kuh, Diana; Wong, Andrew; Teschendorff, Andrew E.; Widschwendter, Martin; Ritz, Beate R.; Absher, Devin; Assimes, Themistocles L.; Horvath, Steve

    2016-01-01

    Although epigenetic processes have been linked to aging and disease in other systems, it is not yet known whether they relate to reproductive aging. Recently, we developed a highly accurate epigenetic biomarker of age (known as the “epigenetic clock”), which is based on DNA methylation levels. Here we carry out an epigenetic clock analysis of blood, saliva, and buccal epithelium using data from four large studies: the Women's Health Initiative (n = 1,864); Invecchiare nel Chianti (n = 200); Parkinson's disease, Environment, and Genes (n = 256); and the United Kingdom Medical Research Council National Survey of Health and Development (n = 790). We find that increased epigenetic age acceleration in blood is significantly associated with earlier menopause (P = 0.00091), bilateral oophorectomy (P = 0.0018), and a longer time since menopause (P = 0.017). Conversely, epigenetic age acceleration in buccal epithelium and saliva do not relate to age at menopause; however, a higher epigenetic age in saliva is exhibited in women who undergo bilateral oophorectomy (P = 0.0079), while a lower epigenetic age in buccal epithelium was found for women who underwent menopausal hormone therapy (P = 0.00078). Using genetic data, we find evidence of coheritability between age at menopause and epigenetic age acceleration in blood. Using Mendelian randomization analysis, we find that two SNPs that are highly associated with age at menopause exhibit a significant association with epigenetic age acceleration. Overall, our Mendelian randomization approach and other lines of evidence suggest that menopause accelerates epigenetic aging of blood, but mechanistic studies will be needed to dissect cause-and-effect relationships further. PMID:27457926

  17. Relativity and accelerator engineering

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Schenefeld (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-09-15

    From a geometrical viewpoint, according to the theory of relativity, space and time constitute a four-dimensional continuum with pseudo-Euclidean structure. This has recently begun to be a practically important statement in accelerator physics. An X-ray Free Electron Laser (XFEL) is in fact the best, exciting example of an engineering system where improvements in accelerator technology makes it possible to develop ultrarelativistic macroscopic objects with an internal fine structure, and the theory of relativity plays an essential role in their description. An ultrarelativistic electron bunch modulated at nanometer-scale in XFELs has indeed a macroscopic finite-size of order of 10 μm. Its internal, collective structure is characterized in terms of a wave number vector. Here we will show that a four-dimensional geometrical approach, unusual in accelerator physics, is needed to solve problems involving the emission of radiation from an ultrarelativistic modulated electron beam accelerating along a curved trajectory. We will see that relativistic kinematics enters XFEL physics in a most fundamental way through the so-called Wigner rotation of the modulation wave number vector, which is closely associated to the relativity of simultaneity. If not taken into account, relativistic kinematics effects would lead to a strong qualitative disagreement between theory and experiments. In this paper, several examples of relativistic kinematics effects, which are important for current and future XFEL operation, are studied. The theory of relativity is applied by providing details of the clock synchronization procedure within the laboratory frame. This approach, exploited here but unusual in literature, is rather ''practical'', and should be acceptable to accelerator physicists.

  18. Rainforest-initiated wet season onset over the southern Amazon.

    Science.gov (United States)

    Wright, Jonathon S; Fu, Rong; Worden, John R; Chakraborty, Sudip; Clinton, Nicholas E; Risi, Camille; Sun, Ying; Yin, Lei

    2017-08-08

    Although it is well established that transpiration contributes much of the water for rainfall over Amazonia, it remains unclear whether transpiration helps to drive or merely responds to the seasonal cycle of rainfall. Here, we use multiple independent satellite datasets to show that rainforest transpiration enables an increase of shallow convection that moistens and destabilizes the atmosphere during the initial stages of the dry-to-wet season transition. This shallow convection moisture pump (SCMP) preconditions the atmosphere at the regional scale for a rapid increase in rain-bearing deep convection, which in turn drives moisture convergence and wet season onset 2-3 mo before the arrival of the Intertropical Convergence Zone (ITCZ). Aerosols produced by late dry season biomass burning may alter the efficiency of the SCMP. Our results highlight the mechanisms by which interactions among land surface processes, atmospheric convection, and biomass burning may alter the timing of wet season onset and provide a mechanistic framework for understanding how deforestation extends the dry season and enhances regional vulnerability to drought.

  19. Onset of nuclear boiling in forced convection (Method of detection)

    International Nuclear Information System (INIS)

    Rachedi, M.

    1986-01-01

    Local onset of boiling in any pressure water cooling systems, as a PWR for instance, can mean a possible dangerous mismatch between the produced heat and the cooling capabilities. Its consequences can lead to serious accidental conditions and a reliable technique to detect such a phenomenon is therefore of particular need. Most techniques used up to now rely basically on local measurements and assume therefore usually the previous knowledge of the actual hot or boiling spot. The method proposed here based on externally located accelerometers appears to be sensitive to the global behaviour of the mechanical structure and is therefore not particularly bound to any exact localization of the sensors. The vibrations produced in the mechanical structure of the heated assembly are measured by accelerometers placed on the external surfaces that are easily accessible. The onset of the boiling, the growth and condensation of the bubbles on the heated wall, induces a resonance in the structure and an excitation at its particular eigen frequencies. Distinctive peaks are clearly observed in the spectral density function calculated from the accelerometer signal as soon as bubbles are produced. The technique is shown to be very sensitive even at the earliest phase of boiling and quite independent on sensor position. A complete hydrodynamic analysis of the experimental channels have been performed in order to assess the validity of the method both in steady conditions and during rapid power transients

  20. Self-leveling onset criteria in debris beds

    International Nuclear Information System (INIS)

    Zhang, Bin; Harada, Tetsushi; Hirahara, Daisuke; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2010-01-01

    In a core-disruptive accident of a sodium-cooled fast breeder reactor, core debris may settle on the core-support structure and/or in the lower inlet plenum of the reactor vessel because of rapid quenching and fragmentation of molten core materials in the subcooled sodium plenum. Coolant boiling is the mechanism driving the self-leveling of a debris bed that causes significant changes in the heat-removal capability of the beds. In the present study, we develop criteria establishing the onset of this self-leveling behavior that we base on a force balance model assuming a debris bed with a single-sized spherical particle. The model considers drag, buoyancy, and gravity acting on each particle. A series of experiments with simulant materials verified the applicability of this description of self-leveling. Particle size (between 0.5-6 mm), shape (spherical and nonspherical), density (namely of alumina, zirconia, lead, and stainless steel), along with boiling intensity, bed volume, and even experimental methods were taken into consideration to obtain general characteristics of the self-leveling process. We decided to use depressurization boiling to simulate an axially increasing void distribution in the debris bed, although bottom heating was also used to validate the use of the depressurization method. On the self-leveling onset issues, we obtained good agreement between model predictions and experimental results. Extrapolation of our model to actual reactor conditions is discussed. (author)

  1. Is Adolescent-Onset First-Episode Psychosis Different from Adult Onset?

    Science.gov (United States)

    Ballageer, Trevor; Malla, Ashok; Manchanda, Rahul; Takhar, Jatinder; Haricharan, Raj

    2005-01-01

    Objective: To examine whether first-episode psychosis patients with onset during adolescence (ages 15-18) differ significantly from those with young-adult onset (ages 19-30). Method: Consecutive patients presenting with first-episode psychosis (N = 242) were assessed for demographic and illness characteristics such as duration of untreated…

  2. Temporal relationship between onset of Graves' ophthalmopathy and onset of thyroidal Graves' disease

    NARCIS (Netherlands)

    Wiersinga, W. M.; Smit, T.; van der Gaag, R.; Koornneef, L.

    1988-01-01

    The temporal relationship between the onset of Graves' ophthalmopathy and the onset of thyroidal Graves' disease was evaluated in 125 consecutive patients with Graves' ophthalmopathy. Thyroidal Graves' disease--past or present--was clinically evident in 99 patients (79%): hyperthyroidism in 3 cases.

  3. Analysis of flame acceleration in open or vented obstructed pipes

    Science.gov (United States)

    Bychkov, Vitaly; Sadek, Jad; Akkerman, V'yacheslav

    2017-01-01

    While flame propagation through obstacles is often associated with turbulence and/or shocks, Bychkov et al. [V. Bychkov et al., Phys. Rev. Lett. 101, 164501 (2008), 10.1103/PhysRevLett.101.164501] have revealed a shockless, conceptually laminar mechanism of extremely fast flame acceleration in semiopen obstructed pipes (one end of a pipe is closed; a flame is ignited at the closed end and propagates towards the open one). The acceleration is devoted to a powerful jet flow produced by delayed combustion in the spaces between the obstacles, with turbulence playing only a supplementary role in this process. In the present work, this formulation is extended to pipes with both ends open in order to describe the recent experiments and modeling by Yanez et al. [J. Yanez et al., arXiv:1208.6453] as well as the simulations by Middha and Hansen [P. Middha and O. R. Hansen, Process Safety Prog. 27, 192 (2008) 10.1002/prs.10242]. It is demonstrated that flames accelerate strongly in open or vented obstructed pipes and the acceleration mechanism is similar to that in semiopen ones (shockless and laminar), although acceleration is weaker in open pipes. Starting with an inviscid approximation, we subsequently incorporate hydraulic resistance (viscous forces) into the analysis for the sake of comparing its role to that of a jet flow driving acceleration. It is shown that hydraulic resistance is actually not required to drive flame acceleration. In contrast, this is a supplementary effect, which moderates acceleration. On the other hand, viscous forces are nevertheless an important effect because they are responsible for the initial delay occurring before the flame acceleration onset, which is observed in the experiments and simulations. Accounting for this effect provides good agreement between the experiments, modeling, and the present theory.

  4. Electron accelerator for tunneling through hard rock

    International Nuclear Information System (INIS)

    Avery, R.T.; Keefe, D.

    1975-10-01

    Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented, with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

  5. Electron accelerator for tunneling through hard rock

    International Nuclear Information System (INIS)

    Avery, R.T.; Keefe, D.

    1975-01-01

    Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

  6. Optimizing conditions for an accelerated leach test

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Fuhrmann, M.; Heiser, J.; Franz, E.M.; Colombo, P.

    1988-01-01

    An accelerated leach test for low-level radioactive waste forms is being developed to provide, in a short time, data that can be extrapolated to long time periods. The approach is to provide experimental conditions that will accelerate leaching without changing the dominant release mechanism. Experimental efforts have focused on combining individual factors that have been observed to accelerate leaching. These include elevated temperature, increased leachant volume, and reduced specimen size. The response of diffusion coefficients to various acceleration factors have been evaluated and provide information on experimental parameters that need to be optimized to increase leach rates. For example, these data show that large volumes of leachant are required when leaching portland cement waste forms at elevated temperatures because of high concentrations of dissolved species. Sr-85 leaching is particularly susceptible to suppression due to concentration effects while Cs-137 leaching is less so. Preliminary modeling using a diffusion mechanism (allowing for depletion) of a finite cylinder geometry indicates that during early portions of experiments (daily sampling intervals), leaching is diffusion controlled and more rapid than later in the same experiments (weekly or greater sampling intervals). For cement waste forms, this reduction in rate may be partially controlled by changes in physical structure and chemistry (sometimes related to environmental influences such as CO 2 ), but it is more likely associated with the duration of the sampling interval. 9 refs., 6 figs

  7. Hypothyroidism in late-onset Pompe disease.

    Science.gov (United States)

    Schneider, Joseph; Burmeister, Lynn A; Rudser, Kyle; Whitley, Chester B; Jarnes Utz, Jeanine

    2016-09-01

    In Pompe disease, a deficiency of acid α-glucosidase enzyme activity leads to pathologic accumulation of glycogen in tissues. Phenotype heterogeneity in Pompe includes an infantile form and late-onset forms (juvenile- and adult-onset forms). Symptoms common to all phenotypes include progressive muscle weakness and worsening respiratory function. Patients with late-onset forms of Pompe disease commonly complain of chronic fatigue and generalized muscle weakness prior to being diagnosed with Pompe disease, and this may lead to consideration of hypothyroidism in the differential diagnosis. This study aimed to evaluate the prevalence of hypothyroidism in the adult-onset form of Pompe disease. Electronic chart review was performed at the Advanced Therapies Clinic at the University of Minnesota Medical Center (UMMC) to identify patients with late-onset Pompe disease. The identified charts were reviewed for a co-diagnosis of hypothyroidism. A query was made to the clinical data repository at UMMC searching diagnosis ICD9 code 244.9 (hypothyroidism not otherwise specified) and/or presence of levothyroxine from 2011 to 2014 in patients 18 years of age and older. The clinical data repository found a prevalence of hypothyroidism of 3.15% (56,072 of 1,782,720 patients) in the adult patient population at UMMC. Ten adult patients with Pompe disease were identified, five with the diagnosis of hypothyroidism (50%, 95% CI: 23.7, 76.3, p Hypothyroidism was found at a higher prevalence in patients with late-onset Pompe disease compared to the general adult population at UMMC. Studies in larger populations of patients with Pompe disease would be needed to confirm an association of Pompe disease and hypothyroidism. Challenges include finding an adequate sample size, due the rarity of Pompe disease.

  8. Late Onset Bipolar Disorder: Case Report

    Directory of Open Access Journals (Sweden)

    Filipa Araújo

    2016-07-01

    Full Text Available Background: Bipolar disorder affects approximately 1% of the population, with diagnosis often being made during late adolescence and early adulthood, and only rarely (0.1% in the elderly. Late onset bipolar disorder in the elderly has a impact on the nature and course of bipolar disorder. Aims: The authors report a case of bipolar disorder emerging in late life  (76years old with no cleary identified organic cause. Conclusion: This case highlights the importance of a broad differential diagnosis and pharmacologic management when approaching new-onset manic/depressive symptoms among geriatric patients.

  9. A case of late-onset oligomeganephronia

    Directory of Open Access Journals (Sweden)

    Rafael José Vargas Alves

    2012-12-01

    Full Text Available A 33-year old caucasian man was investigated for pain in the right flank, proteinuria, hemathuria and an elevated serum creatinine level. He also presented an abnormal ultrasonography, which revealed asymmetric kidneys. Through renal biopsy, the diagnosis of oligomeganephronia (OMN was confirmed. OMN is a very rare form of renal hypoplasia, and late-onset in adulthood is even rarer. In the pediatric population, OMN leads to end-stage-renal-failure(ESRF in a few years. This is the sixth case related in the literature of a late-onset OMN who have not yet developed ESRF.

  10. Adult onset sporadic ataxias: a diagnostic challenge

    Directory of Open Access Journals (Sweden)

    Orlando Graziani Povoas Barsottini

    2014-03-01

    Full Text Available Patients with adult onset non-familial progressive ataxia are classified in sporadic ataxia group. There are several disease categories that may manifest with sporadic ataxia: toxic causes, immune-mediated ataxias, vitamin deficiency, infectious diseases, degenerative disorders and even genetic conditions. Considering heterogeneity in the clinical spectrum of sporadic ataxias, the correct diagnosis remains a clinical challenge. In this review, the different disease categories that lead to sporadic ataxia with adult onset are discussed with special emphasis on their clinical and neuroimaging features, and diagnostic criteria.

  11. Acceleration of polarized proton beams

    International Nuclear Information System (INIS)

    Roser, T.

    1998-01-01

    The acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. Full Siberian snakes are being developed for RHIC to make the acceleration of polarized protons to 250 GeV possible. A similar scheme is being studied for the 800 GeV HERA proton accelerator

  12. Nonlinear dynamics in particle accelerators

    CERN Document Server

    Dilão, Rui

    1996-01-01

    This book is an introductory course to accelerator physics at the level of graduate students. It has been written for a large audience which includes users of accelerator facilities, accelerator physicists and engineers, and undergraduates aiming to learn the basic principles of construction, operation and applications of accelerators.The new concepts of dynamical systems developed in the last twenty years give the theoretical setting to analyse the stability of particle beams in accelerator. In this book a common language to both accelerator physics and dynamical systems is integrated and dev

  13. Unlimited Relativistic Shock Surfing Acceleration

    International Nuclear Information System (INIS)

    Ucer, D.; Shapiro, V. D.

    2001-01-01

    Nonrelativistic shock surfing acceleration at quasiperpendicular shocks is usually considered to be a preacceleration mechanism for slow pickup ions to initiate diffusive shock acceleration. In shock surfing, the particle accelerates along the shock front under the action of the convective electric field of the plasma flow. However, the particle also gains kinetic energy normal to the shock and eventually escapes downstream. We consider the case when ions are accelerated to relativistic velocities. In this case, the ions are likely to be trapped for infinitely long times, because the energy of bounce oscillations tends to decrease during acceleration. This suggests the possibility of unlimited acceleration by shock surfing

  14. Cerebellar pathology in childhood-onset vs. adult-onset essential tremor.

    Science.gov (United States)

    Louis, Elan D; Kuo, Sheng-Han; Tate, William J; Kelly, Geoffrey C; Faust, Phyllis L

    2017-10-17

    Although the incidence of ET increases with advancing age, the disease may begin at any age, including childhood. The question arises as to whether childhood-onset ET cases manifest the same sets of pathological changes in the cerebellum as those whose onset is during adult life. We quantified a broad range of postmortem features (Purkinje cell [PC] counts, PC axonal torpedoes, a host of associated axonal changes [PC axonal recurrent collateral count, PC thickened axonal profile count, PC axonal branching count], heterotopic PCs, and basket cell rating) in 60 ET cases (11 childhood-onset and 49 adult-onset) and 30 controls. Compared to controls, childhood-onset ET cases had lower PC counts, higher torpedo counts, higher heterotopic PC counts, higher basket cell plexus rating, and marginally higher PC axonal recurrent collateral counts. The median PC thickened axonal profile count and median PC axonal branching count were two to five times higher in childhood-onset ET than controls, but the differences did not reach statistical significance. Childhood-onset and adult-onset ET had similar PC counts, torpedo counts, heterotopic PC counts, basket cell plexus rating, PC axonal recurrent collateral counts, PC thickened axonal profile count and PC axonal branching count. In conclusion, we found that childhood-onset and adult-onset ET shared similar pathological changes in the cerebellum. The data suggest that pathological changes we have observed in the cerebellum in ET are a part of the pathophysiological cascade of events in both forms of the disease and that both groups seem to reach the same pathological endpoints at a similar age of death. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Radiocarbon dating with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Blake, W. Jr.

    1985-01-01

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  16. Second International Conference on Accelerating Biopharmaceutical Development

    Science.gov (United States)

    2009-01-01

    The Second International Conference on Accelerating Biopharmaceutical Development was held in Coronado, California. The meeting was organized by the Society for Biological Engineering (SBE) and the American Institute of Chemical Engineers (AIChE); SBE is a technological community of the AIChE. Bob Adamson (Wyeth) and Chuck Goochee (Centocor) were co-chairs of the event, which had the theme “Delivering cost-effective, robust processes and methods quickly and efficiently.” The first day focused on emerging disruptive technologies and cutting-edge analytical techniques. Day two featured presentations on accelerated cell culture process development, critical quality attributes, specifications and comparability, and high throughput protein formulation development. The final day was dedicated to discussion of technology options and new analysis methods provided by emerging disruptive technologies; functional interaction, integration and synergy in platform development; and rapid and economic purification process development. PMID:20065637

  17. Accelerator mass spectrometry at the Rossendorf 5 MV tandem accelerator

    International Nuclear Information System (INIS)

    Friedrich, M.; Buerger, W.; Curian, H.; Hartmann, B.; Hentschel, E.; Matthes, H.; Probst, W.; Seidel, M.; Turuc, S.; Hebert, D.; Rothe, T.; Stolz, W.

    1992-01-01

    The Rossendorf electrostatic accelerators (5 MV tandem accelerator and single ended 2 MV van de Graaff accelerator) are already used for ion beam analysis. The existing methods (RBS, PIXE, ERDA, NRA, nuclear microprobe and external beam) will be completed by introduction of Accelerator Mass Spectrometry (AMS). A short description of the Rossendorf AMS system is given and first experimental results are presented. (R.P.) 4 refs.; 6 figs

  18. SALOME: An Accelerator for the Practical Course in Accelerator Physics

    OpenAIRE

    Miltchev, Velizar; Riebesehl, Daniel; Roßbach, Jörg; Trunk, Maximilian; Stein, Oliver

    2014-01-01

    SALOME (Simple Accelerator for Learning Optics and the Manipulation of Electrons) is a short low energy linear electron accelerator built by the University of Hamburg. The goal of this project is to give the students the possibility to obtain hands-on experience with the basics of accelerator physics. In this contribution the layout of the device will be presented. The most important components of the accelerator will be discussed and an overview of the planned demonstration experiments will ...

  19. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  20. IFMIF accelerators design

    International Nuclear Information System (INIS)

    Mosnier, A.; Ratzinger, U.

    2008-01-01

    The IFMIF requirement for 250 mA current of deuteron beams at a nominal energy of 40 MeV is met by means of two identical continuous wave (CW) 175 MHz linear accelerators running in parallel, each delivering a 125 mA, 40 MeV deuteron beam to the common target. This approach allows to stay within the current capability of present RF linac technology while providing operational redundancy in case of failure of one of the linacs. Each linac comprises a sequence of acceleration and beam transport/matching stages. The ion source generates a 140 mA deuteron beam at 100 keV. A low energy beam transport (LEBT) transfers the deuteron beam from the source to a radio frequency quadrupole (RFQ) cavity. The RFQ bunches and accelerates the 125 mA beam to 5 MeV. The RFQ output beam is injected through a matching section into a drift-tube-linac (DTL) where it is accelerated to the final energy of 40 MeV. In the reference design, the final acceleration stage is a conventional Alvarez-type DTL with post-couplers operating at room temperature. Operation of both the RFQ and the DTL at the same relatively low frequency is essential for accelerating the high current deuteron beam with low beam loss. The primary concern of the IFMIF linacs is the minimization of beam losses, which could limit their availability and maintainability due to excessive activation of the linac and irradiation of the environment. A careful beam dynamics design is therefore needed from the source to the target to avoid the formation of particle halo that could finally be lost in the linac or transfer lines. A superconducting solution for the high energy portion of the linac using, for example, CH-structure or coaxial-type resonators, could offer some advantages, in particular the reduction of operational costs. Careful beam dynamics simulations and comparison tests with beam during the EVEDA phase are however necessary in order to fully assess the technical feasibility of such alternative solutions