Excessive Daytime Sleepiness Predicts Neurodegeneration in Idiopathic REM Sleep Behavior Disorder.

Science.gov (United States)

Zhou, Junying; Zhang, Jihui; Lam, Siu Ping; Chan, Joey Wy; Mok, Vincent; Chan, Anne; Li, Shirley Xin; Liu, Yaping; Tang, Xiangdong; Yung, Wing Ho; Wing, Yun Kwok

2017-05-01

To determine the association of excessive daytime sleepiness (EDS) with the conversion of neurodegenerative diseases in patients with idiopathic REM sleep behavior disorder (iRBD). A total of 179 patients with iRBD (79.1% males, mean age = 66.3 ± 9.8 years) were consecutively recruited. Forty-five patients with Epworth Sleepiness Scale score ≥14 were defined as having EDS. Demographic, clinical, and polysomnographic data were compared between iRBD patients with and without EDS. The risk of developing neurodegenerative diseases was examined using Cox proportional hazards model. After a mean follow-up of 5.8 years (SD = 4.3 years), 50 (27.9%) patients developed neurodegenerative diseases. There was a significantly higher proportion of conversion in patients with EDS compared to those without EDS (42.2 % vs. 23.1%, p = .01). EDS significantly predicted an increased risk of developing neurodegenerative diseases (adjusted hazard ratios [HR] = 2.56, 95% confidence interval [CI] 1.37 to 4.77) after adjusting for age, sex, body mass index, current depression, obstructive sleep apnea, and periodic limb movements during sleep. Further analyses demonstrated that EDS predicted the conversion of Parkinson's disease (PD) (adjusted HR = 3.55, 95% CI 1.59 to 7.89) but not dementia (adjusted HR = 1.48, 95% CI 0.44 to 4.97). EDS is associated with an increased risk of developing neurodegenerative diseases, especially PD, in patients with iRBD. Our findings suggest that EDS is a potential clinical biomarker of α-synucleinopathies in iRBD. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Shutdown radiation level and man-rem control for water cooled reactors

International Nuclear Information System (INIS)

Cripps, S.J.; Regan, J.D.

1978-01-01

The importance of controlling the formation and subsequent deposition of active corrosion products (crud) is highlighted as a method of reducing occupational exposure. A semi-empirical model is described and used to predict the effectiveness of various methods of crud control. The relative merits of reactor coolant clean-up techniques including ion-exchange and electromagnetic filtration are assessed in terms of man-rem savings and associated cost penalties. (author)

Diagnostic thresholds for quantitative REM sleep phasic burst duration, phasic and tonic muscle activity, and REM atonia index in REM sleep behavior disorder with and without comorbid obstructive sleep apnea.

Science.gov (United States)

McCarter, Stuart J; St Louis, Erik K; Duwell, Ethan J; Timm, Paul C; Sandness, David J; Boeve, Bradley F; Silber, Michael H

2014-10-01

We aimed to determine whether phasic burst duration and conventional REM sleep without atonia (RSWA) methods could accurately diagnose REM sleep behavior disorder (RBD) patients with comorbid OSA. We visually analyzed RSWA phasic burst durations, phasic, "any," and tonic muscle activity by 3-s mini-epochs, phasic activity by 30-s (AASM rules) epochs, and conducted automated REM atonia index (RAI) analysis. Group RSWA metrics were analyzed and regression models fit, with receiver operating characteristic (ROC) curves determining the best diagnostic cutoff thresholds for RBD. Both split-night and full-night polysomnographic studies were analyzed. N/A. Parkinson disease (PD)-RBD (n = 20) and matched controls with (n = 20) and without (n = 20) OSA. N/A. All mean RSWA phasic burst durations and muscle activities were higher in PD-RBD patients than controls (P sleep without atonia diagnostic thresholds applicable in Parkinson disease-REM sleep behavior disorder (PD-RBD) patient populations with comorbid OSA that may be useful toward distinguishing PD-RBD in typical outpatient populations. © 2014 Associated Professional Sleep Societies, LLC.

An extended range neutron rem counter

International Nuclear Information System (INIS)

Birattari, C.; Nuccetelli, C.; Pelliccioni, M.; Silari, M.

1990-01-01

Extensive Monte Carlo calculations have been carried out to assess the possibility of extending the sensitivity of a neutron rem counter of the Andersson-Braun type up to several hundred MeV. The validity of the model adopted has first been checked by comparing with experimental data the calculated response curve and the angular dependence of the sensitivity for a well known commercial rem counter. Next, a number of modifications to the configuration of the moderator-attenuator have been investigated. The response functions and angular distributions produced by two simple solutions yielding an instrument with a sensitivity extended up to 400 MeV are presented. The response of the original rem counter and of its two modified versions to nine test spectra has also been calculated. The resulting instrument is transportable rather than portable, but the availability of an extended range neutron survey meter would be of great advantage at medium and high energy particle accelerator facilities. (orig.)

Overnight improvements in two REM sleep-sensitive tasks are associated with both REM and NREM sleep changes, sleep spindle features, and awakenings for dream recall.

Science.gov (United States)

Nielsen, T; O'Reilly, C; Carr, M; Dumel, G; Godin, I; Solomonova, E; Lara-Carrasco, J; Blanchette-Carrière, C; Paquette, T

2015-07-01

Memory consolidation is associated with sleep physiology but the contribution of specific sleep stages remains controversial. To clarify the contribution of REM sleep, participants were administered two REM sleep-sensitive tasks to determine if associated changes occurred only in REM sleep. Twenty-two participants (7 men) were administered the Corsi Block Tapping and Tower of Hanoi tasks prior to and again after a night of sleep. Task improvers and non-improvers were compared for sleep structure, sleep spindles, and dream recall. Control participants (N = 15) completed the tasks twice during the day without intervening sleep. Overnight Corsi Block improvement was associated with more REM sleep whereas Tower of Hanoi improvement was associated with more N2 sleep. Corsi Block improvement correlated positively with %REM sleep and Tower of Hanoi improvement with %N2 sleep. Post-hoc analyses suggest Tower of Hanoi effects-but not Corsi Block effects-are due to trait differences. Sleep spindle density was associated with Tower of Hanoi improvement whereas spindle amplitude correlated with Corsi Block improvement. Number of REM awakenings for dream reporting (but not dream recall per se) was associated with Corsi Block, but not Tower of Hanoi, improvement but was confounded with REM sleep time. This non-replication of one of 2 REM-sensitive task effects challenges both 'dual-process' and 'sequential' or 'sleep organization' models of sleep-dependent learning and points rather to capacity limitations on REM sleep. Experimental awakenings for sampling dream mentation may not perturb sleep-dependent learning effects; they may even enhance them. Copyright © 2014 Elsevier Inc. All rights reserved.

Diagnostic REM sleep muscle activity thresholds in patients with idiopathic REM sleep behavior disorder with and without obstructive sleep apnea.

Science.gov (United States)

McCarter, Stuart J; St Louis, Erik K; Sandness, David J; Duwell, Ethan J; Timm, Paul C; Boeve, Bradley F; Silber, Michael H

2017-05-01

We aimed to determine whether visual and automated rapid eye movement (REM) sleep without atonia (RSWA) methods could accurately diagnose patients with idiopathic REM sleep behavior disorder (iRBD) and comorbid obstructive sleep apnea (OSA). In iRBD patients (n = 15) and matched controls (n = 30) with and without OSA, we visually analyzed RSWA phasic burst durations, phasic, tonic, and "any" muscle activity by 3-s mini-epochs, phasic activity by 30-s (AASM rules) epochs, and automated REM atonia index (RAI). Group RSWA metrics were analyzed with regression models. Receiver operating characteristic (ROC) curves were used to determine the best diagnostic cutoff thresholds for REM sleep behavior disorder (RBD). Both split-night and full-night polysomnographic studies were analyzed. All mean RSWA phasic burst durations and muscle activities were higher in iRBD patients than in controls (p sleep behavior disorder (PD-RBD), consistent with a common mechanism and presumed underlying etiology of synucleinopathy in both groups. Copyright © 2016 Elsevier B.V. All rights reserved.

Why Does REM Sleep Occur? A Wake-up Hypothesis

Directory of Open Access Journals (Sweden)

Dr. W. R. eKlemm

2011-09-01

Full Text Available Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses REM to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, 1 when first going to sleep, the brain plunges into Stage N3 (formerly called Stage IV, a deep abyss of sleep, and, as the night progresses, the sleep is punctuated by episodes of REM that become longer and more frequent toward morning, 2 conscious-like dreams are a reliable component of the REM state in which the dreamer is an active mental observer or agent in the dream, 3 the last awakening during a night’s sleep usually occurs in a REM episode during or at the end of a dream, 4 both REM and awake consciousness seem to arise out of a similar brainstem ascending arousal system 5 N3 is a functionally perturbed state that eventually must be corrected so that embodied brain can direct adaptive behavior, and 6 corticofugal projections to brainstem arousal areas provide a way to trigger increased cortical activity in REM to progressively raise the sleeping brain to the threshold required for wakefulness. This paper shows how the hypothesis conforms to common experience and has substantial predictive and explanatory power regarding the phenomenology of sleep in terms of ontogeny, aging, phylogeny, abnormal/disease states, cognition, and behavioral physiology. That broad range of consistency is not matched by competing theories, which are summarized herein. Specific ways to test this wake-up hypothesis are suggested. Such research could lead to a better understanding of awake consciousness.

Why does rem sleep occur? A wake-up hypothesis.

Science.gov (United States)

Klemm, W R

2011-01-01

Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses rapid eye movement (REM) to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, (1) when first going to sleep, the brain plunges into Stage N3 (formerly called Stage IV), a deep abyss of sleep, and, as the night progresses, the sleep is punctuated by episodes of REM that become longer and more frequent toward morning, (2) conscious-like dreams are a reliable component of the REM state in which the dreamer is an active mental observer or agent in the dream, (3) the last awakening during a night's sleep usually occurs in a REM episode during or at the end of a dream, (4) both REM and awake consciousness seem to arise out of a similar brainstem ascending arousal system (5) N3 is a functionally perturbed state that eventually must be corrected so that embodied brain can direct adaptive behavior, and (6) cortico-fugal projections to brainstem arousal areas provide a way to trigger increased cortical activity in REM to progressively raise the sleeping brain to the threshold required for wakefulness. This paper shows how the hypothesis conforms to common experience and has substantial predictive and explanatory power regarding the phenomenology of sleep in terms of ontogeny, aging, phylogeny, abnormal/disease states, cognition, and behavioral physiology. That broad range of consistency is not matched by competing theories, which are summarized herein. Specific ways to test this wake-up hypothesis are suggested. Such research could lead to a better understanding of awake consciousness.

Proposed man-rem reference values of occupational exposure

International Nuclear Information System (INIS)

Lombard, J.

1988-04-01

This report presents a proposal of referent collective dose (man-rem) values for occupational exposure related to operation of French pressurized water reactors. These values, permitting adequate choice of protection both at design and operation level, are dependent on the level of annual individual doses. The man-rem value, originating from annual individual doses less than 0.5 rem are estimated to 1 kf. The proposed value is 20 kf for annual individual exposures between 0.5 and 3 rem, and 90 kf for annual individual exposures between 3 and 5 rem. (author) [fr

REM-containing silicate concentrates

Science.gov (United States)

Pavlov, V. F.; Shabanova, O. V.; Pavlov, I. V.; Pavlov, M. V.; Shabanov, A. V.

2016-01-01

A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

REM-containing silicate concentrates

International Nuclear Information System (INIS)

Pavlov, V F; Shabanova, O V; Pavlov, I V; Pavlov, M V; Shabanov, A V

2016-01-01

A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM. (paper)

REM Sleep EEG Instability in REM Sleep Behavior Disorder and Clonazepam Effects.

Science.gov (United States)

Ferri, Raffaele; Rundo, Francesco; Silvani, Alessandro; Zucconi, Marco; Bruni, Oliviero; Ferini-Strambi, Luigi; Plazzi, Giuseppe; Manconi, Mauro

2017-08-01

We aimed to analyze quantitatively rapid eye movement (REM) sleep electroencephalogram (EEG) in controls, drug-naïve idiopathic REM sleep behavior disorder patients (iRBD), and iRBD patients treated with clonazepam. Twenty-nine drug-naïve iRBD patients (mean age 68.2 years), 14 iRBD patients under chronic clonazepam therapy (mean age 66.3 years), and 21 controls (mean age 66.8 years) were recruited. Power spectra were obtained from sleep EEG (central derivation), using a 2-second sliding window, with 1-second steps. The power values of each REM sleep EEG spectral band (one every second) were normalized with respect to the average power value obtained during sleep stage 2 in the same individual. In drug-naïve patients, the normalized power values showed a less pronounced REM-related decrease of power in all bands with frequency sleep EEG structure changes found in this study disclose subtle but significant alterations in the cortical electrophysiology of RBD that might represent the early expression of the supposed neurodegenerative processes already taking place at this stage of the disease and might be the target of better and effective future therapeutic strategies for this condition. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

REM sleep modulation by perifornical orexinergic inputs to the pedunculo-pontine tegmental neurons in rats.

Science.gov (United States)

Khanday, M A; Mallick, B N

2015-11-12

Rapid eye movement sleep (REMS) is regulated by the interaction of the REM-ON and REM-OFF neurons located in the pedunculo-pontine-tegmentum (PPT) and the locus coeruleus (LC), respectively. Many other brain areas, particularly those controlling non-REMS (NREMS) and waking, modulate REMS by modulating these REMS-related neurons. Perifornical (PeF) orexin (Ox)-ergic neurons are reported to increase waking and reduce NREMS as well as REMS; dysfunction of the PeF neurons are related to REMS loss-associated disorders. Hence, we were interested in understanding the neural mechanism of PeF-induced REMS modulation. As a first step we have recently reported that PeF Ox-ergic neurons modulate REMS by influencing the LC neurons (site for REM-OFF neurons). Thereafter, in this in vivo study we have explored the role of PeF inputs on the PPT neurons (site for REM-ON neurons) for the regulation of REMS. Chronic male rats were surgically prepared with implanted bilateral cannulae in PeF and PPT and electrodes for recording sleep-waking patterns. After post-surgical recovery sleep-waking-REMS were recorded when bilateral PeF neurons were stimulated by glutamate and simultaneously bilateral PPT neurons were infused with either saline or orexin receptor1 (OX1R) antagonist. It was observed that PeF stimulation increased waking and decreased NREMS as well as REMS, which were prevented by OX1R antagonist into the PPT. We conclude that the PeF stimulation-induced reduction in REMS was likely to be due to inhibition of REM-ON neurons in the PPT. As waking and NREMS are inversely related, subject to confirmation, the reduction in NREMS could be due to increased waking or vice versa. Based on our findings from this and earlier studies we have proposed a model showing connections between PeF- and PPT-neurons for REMS regulation. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Posttraining Increases in REM Sleep Intensity Implicate REM Sleep in Memory Processing and Provide a Biological Marker of Learning Potential

Science.gov (United States)

Nader, Rebecca S.; Smith, Carlyle T.; Nixon, Margaret R.

2004-01-01

Posttraining rapid eye movement (REM) sleep has been reported to be important for efficient memory consolidation. The present results demonstrate increases in the intensity of REM sleep during the night of sleep following cognitive procedural/implicit task acquisition. These REM increases manifest as increases in total number of rapid eye…

Olfactory impairment is related to REM sleep deprivation in rotenone model of Parkinson's disease

Directory of Open Access Journals (Sweden)

Mariana F. Aurich

Full Text Available Introduction: Olfactory dysfunction affects about 85-90% of Parkinson's disease (PD patients with severe deterioration in the ability of discriminate several types of odors. In addition, studies reported declines in olfactory performances during a short period of sleep deprivation. Besides, PD is also known to strongly affect the occurrence and maintenance of rapid eye movement (REM sleep. Methods: Therefore, we investigated the mechanisms involved on discrimination of a social odor (dependent on the vomeronasal system and a non-social odor (related to the main olfactory pathway in the rotenone model of PD. Also, a concomitant impairment in REM sleep was inflicted with the introduction of two periods (24 or 48 h of REM sleep deprivation (REMSD. Rotenone promoted a remarkable olfactory impairment in both social and non-social odors, with a notable modulation induced by 24 h of REMSD for the non-social odor. Results: Our findings demonstrated the occurrence of a strong association between the density of nigral TH-ir neurons and the olfactory discrimination capacity for both odorant stimuli. Specifically, the rotenone-induced decrease of these neurons tends to elicit reductions in the olfactory discrimination ability. Conclusions: These results are consistent with the participation of the nigrostriatal dopaminergic system mainly in the olfactory discrimination of a non-social odor, probably through the main olfactory pathway. Such involvement may have produce relevant impact in the preclinical abnormalities found in PD patients.

RemBench: A Digital Workbench for Rembrandt Research

NARCIS (Netherlands)

Verberne, Suzan; Van Leeuwen, Rudie; Gerritsen, G.H.; Boves, Lou

2016-01-01

In this paper, we present RemBench, a search engine for research into the life and works of Rembrandt van Rijn. RemBench combines the data from four different databases behind one interface using federated search technology. Metadata filtering is enabled through faceted search. RemBench enables art

Implementation and evaluation of pH-dependent cloud chemistry and wetdeposition in the chemical transport model REM-Calgrid

NARCIS (Netherlands)

Banzhaf, S.; Schaap, M.; Kerschbaumer, A.; Reimer, E.; Stern, R.; Swaluw, E. van der; Builtjes, P.

2012-01-01

The Chemistry Transport Model REM-Calgrid (RCG) has been improved by implementing an enhanced description of aqueous-phase chemistry and wet deposition processes including droplet pH. A sensitivity study on cloud and rain droplet pH has been performed to investigate its impact on model sulphate

REM behaviour disorder detection associated with neurodegenerative diseases

DEFF Research Database (Denmark)

Kempfner, Jacob; Sorensen, Gertrud; Zoetmulder, Marielle

2010-01-01

Abnormal skeleton muscle activity during REM sleep is characterized as REM Behaviour Disorder (RBD), and may be an early marker for different neurodegenerative diseases. Early detection of RBD is therefore highly important, and in this ongoing study a semi-automatic method for RBD detection......, a computerized algorithm has been attempted implemented. By analysing the REM and non-REM EMG activity, using advanced signal processing tools combined with a statistical classifier, it is possible to discriminate normal and abnormal EMG activity. Due to the small number of patients, the overall performance...

Evaluating the evidence surrounding pontine cholinergic involvement in REM sleep generation

Directory of Open Access Journals (Sweden)

Kevin P Grace

2015-09-01

Full Text Available Rapid eye movement (REM sleep - characterized by vivid dreaming, motor paralysis, and heightened neural activity - is one of the fundamental states of the mammalian central nervous system. Initial theories of rapid eye movement (REM sleep generation posited that induction of the state required activation of the ‘pontine REM sleep generator’ by cholinergic inputs. Here we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii loss-of-function studies show that endogenous cholinergic input to the PFT is not required for REM sleep generation, and (iv Cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail.

Selective REM Sleep Deprivation Improves Expectation-Related Placebo Analgesia.

Science.gov (United States)

Chouchou, Florian; Chauny, Jean-Marc; Rainville, Pierre; Lavigne, Gilles J

2015-01-01

The placebo effect is a neurobiological and psychophysiological process known to influence perceived pain relief. Optimization of placebo analgesia may contribute to the clinical efficacy and effectiveness of medication for acute and chronic pain management. We know that the placebo effect operates through two main mechanisms, expectations and learning, which is also influenced by sleep. Moreover, a recent study suggested that rapid eye movement (REM) sleep is associated with modulation of expectation-mediated placebo analgesia. We examined placebo analgesia following pharmacological REM sleep deprivation and we tested the hypothesis that relief expectations and placebo analgesia would be improved by experimental REM sleep deprivation in healthy volunteers. Following an adaptive night in a sleep laboratory, 26 healthy volunteers underwent classical experimental placebo analgesic conditioning in the evening combined with pharmacological REM sleep deprivation (clonidine: 13 volunteers or inert control pill: 13 volunteers). Medication was administered in a double-blind manner at bedtime, and placebo analgesia was tested in the morning. Results revealed that 1) placebo analgesia improved with REM sleep deprivation; 2) pain relief expectations did not differ between REM sleep deprivation and control groups; and 3) REM sleep moderated the relationship between pain relief expectations and placebo analgesia. These results support the putative role of REM sleep in modulating placebo analgesia. The mechanisms involved in these improvements in placebo analgesia and pain relief following selective REM sleep deprivation should be further investigated.

REM sleep at its core—Circuits, neurotransmitters and pathophysiology

Directory of Open Access Journals (Sweden)

John ePeever

2015-05-01

Full Text Available REM sleep is generated and maintained by the interaction of a variety of neurotransmitter systems in the brainstem, forebrain and hypothalamus. Within these circuits lies a core region that is active during REM sleep, known as the subcoeruleus nucleus (SubC or sublaterodorsal nucleus. It is hypothesized that glutamatergic SubC neurons regulate REM sleep and its defining features such as muscle paralysis and cortical activation. REM sleep paralysis is initiated when glutamatergic SubC activate neurons in the ventral medial medulla (VMM, which causes release of GABA and glycine onto skeletal motoneurons. REM sleep timing is controlled by activity of GABAergic neurons in the ventrolateral periaqueductal gray (vlPAG and dorsal paragigantocellular reticular nucleus (DPGi as well as melanin-concentrating hormone (MCH neurons in the hypothalamus and cholinergic cells in the laterodorsal (LDT and pedunculo-pontine tegmentum (PPT in the brainstem. Determining how these circuits interact with the SubC is important because breakdown in their communication is hypothesized to underlie cataplexy/narcolepsy and REM sleep behaviour disorder (RBD. This review synthesizes our current understanding of mechanisms generating healthy REM sleep and how dysfunction of these circuits contributes to common REM sleep disorders such as cataplexy/narcolepsy and RBD.

A methodology for costing man-rem

International Nuclear Information System (INIS)

Bieber, C.

1976-03-01

An attempt is made to provide a methodology for costing man-rem in a way that can be applied to station conditions, based on 1974 Pickering G.S. data. Factors taken into account were social costs, exposure costs (dose accounting, training, dosimetry) temporary labour costs, and permanent replacement labour costs. A figure of $620/ man-rem was derived. (LL)

Levels of Interference in Long and Short-Term Memory Differentially Modulate Non-REM and REM Sleep.

Science.gov (United States)

Fraize, Nicolas; Carponcy, Julien; Joseph, Mickaël Antoine; Comte, Jean-Christophe; Luppi, Pierre-Hervé; Libourel, Paul-Antoine; Salin, Paul-Antoine; Malleret, Gaël; Parmentier, Régis

2016-12-01

It is commonly accepted that sleep is beneficial to memory processes, but it is still unclear if this benefit originates from improved memory consolidation or enhanced information processing. It has thus been proposed that sleep may also promote forgetting of undesirable and non-essential memories, a process required for optimization of cognitive resources. We tested the hypothesis that non-rapid eye movement sleep (NREMS) promotes forgetting of irrelevant information, more specifically when processing information in working memory (WM), while REM sleep (REMS) facilitates the consolidation of important information. We recorded sleep patterns of rats trained in a radial maze in three different tasks engaging either the long-term or short-term storage of information, as well as a gradual level of interference. We observed a transient increase in REMS amount on the day the animal learned the rule of a long-term/reference memory task (RM), and, in contrast, a positive correlation between the performance of rats trained in a WM task involving an important processing of interference and the amount of NREMS or slow wave activity. Various oscillatory events were also differentially modulated by the type of training involved. Notably, NREMS spindles and REMS rapid theta increase with RM training, while sharp-wave ripples increase with all types of training. These results suggest that REMS, but also rapid oscillations occurring during NREMS would be specifically implicated in the long-term memory in RM, whereas NREMS and slow oscillations could be involved in the forgetting of irrelevant information required for WM. © 2016 Associated Professional Sleep Societies, LLC.

Obstructive Sleep Apnea during REM Sleep and Cardiovascular Disease.

Science.gov (United States)

Aurora, R Nisha; Crainiceanu, Ciprian; Gottlieb, Daniel J; Kim, Ji Soo; Punjabi, Naresh M

2018-03-01

Obstructive sleep apnea (OSA) during REM sleep is a common disorder. Data on whether OSA that occurs predominantly during REM sleep is associated with health outcomes are limited. The present study examined the association between OSA during REM sleep and a composite cardiovascular endpoint in a community sample with and without prevalent cardiovascular disease. Full-montage home polysomnography was conducted as part of the Sleep Heart Health Study. The study cohort was followed for an average of 9.5 years, during which time cardiovascular events were assessed. Only participants with a non-REM apnea-hypopnea index (AHI) of less than 5 events/h were included. A composite cardiovascular endpoint was determined as the occurrence of nonfatal or fatal events, including myocardial infarction, coronary artery revascularization, congestive heart failure, and stroke. Proportional hazards regression was used to derive the adjusted hazards ratios for the composite cardiovascular endpoint. The sample consisted of 3,265 subjects with a non-REM AHI of less than 5.0 events/h. Using a REM AHI of less than 5.0 events/h as the reference group (n = 1,758), the adjusted hazards ratios for the composite cardiovascular endpoint in those with severe REM OSA (≥30 events/h; n = 180) was 1.35 (95% confidence interval, 0.98-1.85). Stratified analyses demonstrated that the association was most notable in those with prevalent cardiovascular disease and severe OSA during REM sleep with an adjusted hazards ratio of 2.56 (95% confidence interval, 1.46-4.47). Severe OSA that occurs primarily during REM sleep is associated with higher incidence of a composite cardiovascular endpoint, but in only those with prevalent cardiovascular disease.

Spartan Release Engagement Mechanism (REM) stress and fracture analysis

Science.gov (United States)

Marlowe, D. S.; West, E. J.

1984-01-01

The revised stress and fracture analysis of the Spartan REM hardware for current load conditions and mass properties is presented. The stress analysis was performed using a NASTRAN math model of the Spartan REM adapter, base, and payload. Appendix A contains the material properties, loads, and stress analysis of the hardware. The computer output and model description are in Appendix B. Factors of safety used in the stress analysis were 1.4 on tested items and 2.0 on all other items. Fracture analysis of the items considered fracture critical was accomplished using the MSFC Crack Growth Analysis code. Loads and stresses were obtaind from the stress analysis. The fracture analysis notes are located in Appendix A and the computer output in Appendix B. All items analyzed met design and fracture criteria.

Why REM sleep? Clues beyond the laboratory in a more challenging world.

Science.gov (United States)

Horne, Jim

2013-02-01

REM sleep (REM) seems more likely to prepare for ensuing wakefulness rather than provides recovery from prior wakefulness, as happens with 'deeper' nonREM. Many of REM's characteristics are 'wake-like' (unlike nonREM), including several common to feeding. These, with recent findings outside sleep, provide perspectives on REM beyond those from the laboratory. REM can interchange with a wakefulness involving motor output, indicating that REM's atonia is integral to its function. Wakefulness for 'wild' mammals largely comprises exploration; a complex opportunistic behaviour mostly for foraging, involving: curiosity, minimising risks, (emotional) coping, navigation, when (including circadian timing) to investigate new destinations; all linked to 'purposeful, goal directed movement'. REM reflects these adaptive behaviours (including epigenesis), masked in laboratories having constrained, safe, unchanging, unchallenging, featureless, exploration-free environments with ad lib food. Similarly masked may be REM's functions for today's humans living safe, routine lives, with easy food accessibility. In these respects animal and human REM studies are not sufficiently 'ecological'. Copyright © 2012 Elsevier B.V. All rights reserved.

REM sleep estimation only using respiratory dynamics

International Nuclear Information System (INIS)

Chung, Gih Sung; Choi, Byung Hoon; Lee, Jeong Su; Lee, Jin-Seong; Jeong, Do-Un; Park, Kwang Suk

2009-01-01

Polysomnography (PSG) is currently considered the gold standard for assessing sleep quality. However, the numerous sensors that must be attached to the subject can disturb sleep and limit monitoring to within hospitals and sleep clinics. If data could be obtained without such constraints, sleep monitoring would be more convenient and could be extended to ordinary homes. During rapid-eye-movement (REM) sleep, respiration rate and variability are known to be greater than in other sleep stages. Hence, we calculated the average rate and variability of respiration in an epoch (30 s) by applying appropriate smoothing algorithms. Increased and irregular respiratory patterns during REM sleep were extracted using adaptive and linear thresholds. When both parameters simultaneously showed higher values than the thresholds, the epochs were assumed to belong to REM sleep. Thermocouples and piezoelectric-type belts were used to acquire respiratory signals. Thirteen healthy adults and nine obstructive sleep apnea (OSA) patients participated in this study. Kappa statistics showed a substantial agreement (κ > 0.60) between the standard and respiration-based methods. One-way ANOVA analysis showed no significant difference between the techniques for total REM sleep. This approach can also be applied to the non-intrusive measurement of respiration signals, making it possible to automatically detect REM sleep without disturbing the subject

Management of REM sleep behavior disorder: An evidence based review

OpenAIRE

Preeti Devnani; Racheal Fernandes

2015-01-01

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream enactment behavior resulting from a loss of REM skeletal muscle atonia. The neurobiology of REM sleep and the characteristic features of REM atonia have an important basis for understanding the aggravating etiologies the proposed pharmacological interventions in its management. This review outlines the evidence for behavioral and therapeutic measures along with evidence-based guidelines for their implementation, ...

Auditory Verbal Experience and Agency in Waking, Sleep Onset, REM, and Non-REM Sleep.

Science.gov (United States)

Speth, Jana; Harley, Trevor A; Speth, Clemens

2017-04-01

We present one of the first quantitative studies on auditory verbal experiences ("hearing voices") and auditory verbal agency (inner speech, and specifically "talking to (imaginary) voices or characters") in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants' implicit knowledge of auditory verbal experiences (VE) and auditory verbal agencies (VA), displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement (REM) sleep, non-REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap sleep-wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. Copyright © 2016 Cognitive Science Society, Inc.

Post training REMs coincident auditory stimulation enhances memory in humans.

Science.gov (United States)

Smith, C; Weeden, K

1990-06-01

Sleep activity was monitored in 20 freshman college students for two consecutive nights. Subjects were assigned to 4 equal groups and all were asked to learn a complex logic task before bed on the second night. Two groups of subjects learned the task with a constant clicking noise in the background (cued groups), while two groups simply learned the task (non cued). During the night, one cued and one non cued group were presented with auditory clicks during REM sleep such as to coincide with all REMs of at least 100 microvolts. The second cued group was given auditory clicks during REM sleep, but only during the REMs "quiet" times. The second non-cued control group was never given any nighttime auditory stimulations. The cued REMs coincident group showed a significant 23% improvement in task performance when tested one week later. The non cued REMs coincident group showed only an 8.8% improvement which was not significant. The cued REMs quiet and non-stimulated control groups showed no change in task performance when retested. The results were interpreted as support for the idea that the cued auditory stimulation induced a "recall" of the learned material during the REM sleep state in order for further memory processing to take place.

The Time Course of the Probability of Transition Into and Out of REM Sleep

Science.gov (United States)

Bassi, Alejandro; Vivaldi, Ennio A.; Ocampo-Garcés, Adrián

2009-01-01

Study Objectives: A model of rapid eye movement (REM) sleep expression is proposed that assumes underlying regulatory mechanisms operating as inhomogenous Poisson processes, the overt results of which are the transitions into and out of REM sleep. Design: Based on spontaneously occurring REM sleep episodes (“Episode”) and intervals without REM sleep (“Interval”), 3 variables are defined and evaluated over discrete 15-second epochs using a nonlinear logistic regression method: “Propensity” is the instantaneous rate of into-REM transition occurrence throughout an Interval, “Volatility” is the instantaneous rate of out-of-REM transition occurrence throughout an Episode, and “Opportunity” is the probability of being in non-REM (NREM) sleep at a given time throughout an Interval, a requisite for transition. Setting: 12:12 light:dark cycle, isolated boxes. Participants: Sixteen male Sprague-Dawley rats Interventions: None. Spontaneous sleep cycles. Measurements and Results: The highest levels of volatility and propensity occur, respectively, at the very beginning of Episodes and Intervals. The new condition stabilizes rapidly, and variables reach nadirs at minute 1.25 and 2.50, respectively. Afterward, volatility increases markedly, reaching values close to the initial level. Propensity increases moderately, the increment being stronger through NREM sleep bouts occurring at the end of long Intervals. Short-term homeostasis is evidenced by longer REM sleep episodes lowering propensity in the following Interval. Conclusions: The stabilization after transitions into Episodes or Intervals and the destabilization after remaining for some time in either condition may be described as resulting from continuous processes building up during Episodes and Intervals. These processes underlie the overt occurrence of transitions. Citation: Bassi A; Vivaldi EA; Ocampo-Garcées A. The time course of the probability of transition into and out of REM sleep. SLEEP 2009

Pareidolias in REM Sleep Behavior Disorder: A Possible Predictive Marker of Lewy Body Diseases?

Science.gov (United States)

Sasai-Sakuma, Taeko; Nishio, Yoshiyuki; Yokoi, Kayoko; Mori, Etsuro; Inoue, Yuichi

2017-02-01

To investigate conditions and clinical significance of pareidolias in patients with idiopathic rapid eyemovent (REM) sleep behavior disorder (iRBD). This cross-sectional study examined 202 patients with iRBD (66.8 ± 8.0 yr, 58 female) and 46 healthy control subjects (64.7 ± 5.8 years, 14 females). They underwent the Pareidolia test, a newly developed instrument for evoking pareidolias, video polysomnography, olfactory tests, and Addenbrooke's cognitive examination-revised. Results show that 53.5% of iRBD patients exhibited one or more pareidolic responses: The rate was higher than control subjects showed (21.7%). The pictures evoking pareidolic responses were more numerous for iRBD patients than for control subjects (1.2 ± 1.8 vs. 0.4 ± 0.8, p Pareidolias in iRBD are useful as a predictive marker of future development of Lewy body diseases. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

REM sleep and dreaming functions beyond reductionism.

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Kirov, Roumen

2013-12-01

Brain activation patterns and mental, electrophysiological, and neurobiological features of rapid eye movement (REM) sleep suggest more functions than only elaborative encoding. Hence, the periodic occurrence of REM sleep episodes and dreaming may be regarded as a recurrent adaptive interference, which incorporates recent memories into a broader vital context comprising emotions, basic needs and individual genetic traits.

Monitoring of the prompt GRB afterglow with the REM telescope

International Nuclear Information System (INIS)

Covino, S.; Zerbi, F.; Chincarini, G.; Ghisellini, G.; Conconi, P.; Molinari, E.; Rodono, M.; Cutispoto, G.; Antonelli, L.A.; Nicastro, L.; Palazzi, E.

2003-01-01

In these pages we present REM (Rapid Eye Mount), a fully robotized fast slewing telescope equipped with a high throughput NIR (Z', J, H, K) camera and an Optical slitless spectrograph (ROSS) optimized for the monitoring of the prompt afterglow of Gamma Ray Bursts. Covering the NIR domain REM can discover objects at extremely high red-shift and trigger large telescopes to observe them when they are still bright. The synergy between REM-IR cam and ROSS makes REM a powerful observing tool for any kind of fast transient phenomena

Intrahippocampal administration of anandamide increases REM sleep.

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Rueda-Orozco, Pavel Ernesto; Soria-Gómez, Edgar; Montes-Rodríguez, Corinne Jennifer; Pérez-Morales, Marcel; Prospéro-García, Oscar

2010-04-05

A nascent literature has postulated endocannabinoids (eCBs) as strong sleep-inducing lipids, particularly rapid-eye-movement sleep (REMs), nevertheless the exact mechanisms behind this effect remain to be determined. Anandamide and 2-arachidonyl glycerol, two of the most important eCBS, are synthesized in the hippocampus. This structure also expresses a high concentration of cannabinoid receptor 1 (CB1). Recent extensive literature supports eCBs as important regulators of hippocampal activity. It has also been shown that these molecules vary their expression on the hippocampus depending on the light-dark cycle. In this context we decided to analyze the effect of intrahippocampal administration of the eCB anandamide (ANA) on the sleep-waking cycle at two points of the light-dark cycle. Our data indicate that the administration of ANA directly into the hippocampus increases REMs in a dose dependent manner during the dark but not during the light phase of the cycle. The increase of REMs was blocked by the CB1 antagonist AM251. This effect was specific for the hippocampus since ANA administrations in the surrounding cortex did not elicit any change in REMs. These results support the idea of a direct relationship between hippocampal activity and sleep mechanisms by means of eCBs. The data presented here show, for the first time that eCBs administered into the hippocampus trigger REMs and support previous studies where chemical stimulation of limbic areas triggered sleep.

The effect of REM sleep deprivation on motivation for food reward.

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Hanlon, Erin C; Andrzejewski, Matthew E; Harder, Bridgette K; Kelley, Ann E; Benca, Ruth M

2005-08-30

Prolonged sleep deprivation in rats produces a characteristic syndrome consisting of an increase in food intake yet a decrease in weight. Moreover, the increase in food intake generally precedes the weight loss, suggesting that sleep deprivation may affect appetitive behaviors. Using the multiple platform method to produce rapid eye movement (REM) sleep deprivation, we investigated the effect of REM sleep deprivation (REMSD) on motivation for food reward utilizing food-reinforced operant tasks. In acquisition or maintenance of an operant task, REM sleep-deprived rats, with or without simultaneous food restriction, decreased responding for sucrose pellet reward in comparison to controls, despite the fact that all REM sleep-deprived rats lost weight. Furthermore, the overall response deficit of the REM sleep-deprived rats was due to a within-session decline in responding. REM sleep-deprived rats showed evidence of understanding the contingency of the task comparable to controls throughout deprivation period, suggesting that the decrements in responding were not primarily related to deficits in learning or memory. Rather, REM sleep deprivation appears to alter systems involved in motivational processes, reward, and/or attention.

L-carnitine prevents memory impairment induced by chronic REM-sleep deprivation.

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Alzoubi, Karem H; Rababa'h, Abeer M; Owaisi, Amani; Khabour, Omar F

2017-05-01

Sleep deprivation (SD) negatively impacts memory, which was related to oxidative stress induced damage. L-carnitine is a naturally occurring compound, synthesized endogenously in mammalian species and known to possess antioxidant properties. In this study, the effect of L-carnitine on learning and memory impairment induced by rapid eye movement sleep (REM-sleep) deprivation was investigated. REM-sleep deprivation was induced using modified multiple platform model (8h/day, for 6 weeks). Simultaneously, L-carnitine was administered (300mg/kg/day) intraperitoneally for 6 weeks. Thereafter, the radial arm water maze (RAWM) was used to assess spatial learning and memory. Additionally, the hippocampus levels of antioxidant biomarkers/enzymes: reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG ratio, glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD) and thiobarbituric acid reactive substance (TBARS) were assessed. The results showed that chronic REM-sleep deprivation impaired both short- and long-term memory (Psleep deprivation induced reduction in the hippocampus ratio of GSH/GSSG, activity of catalase, GPx, and SOD. No change was observed in TBARS among tested groups (P>0.05). In conclusion, chronic REM-sleep deprivation induced memory impairment, and treatment with L-carnitine prevented this impairment through normalizing antioxidant mechanisms in the hippocampus. Copyright © 2017 Elsevier Inc. All rights reserved.

Lithium prevents REM sleep deprivation-induced impairments on memory consolidation.

Science.gov (United States)

Ota, Simone M; Moreira, Karin Di Monteiro; Suchecki, Deborah; Oliveira, Maria Gabriela M; Tiba, Paula A

2013-11-01

Pre-training rapid eye movement sleep (REMS) deprivation affects memory acquisition and/or consolidation. It also produces major REMS rebound at the cost of waking and slow wave sleep (SWS). Given that both SWS and REMS appear to be important for memory processes, REMS rebound after training may disrupt the organization of sleep cycles, i.e., excessive amount of REMS and/or little SWS after training could be harmful for memory formation. To examine whether lithium, a drug known to increase SWS and reduce REMS, could prevent the memory impairment induced by pre-training sleep deprivation. Animals were divided in 2 groups: cage control (CC) and REMS-deprived (REMSDep), and then subdivided into 4 subgroups, treated either with vehicle or 1 of 3 doses of lithium (50, 100, and 150 mg/kg) 2 h before training on the multiple trial inhibitory avoidance task. Animals were tested 48 h later to make sure that the drug had been already metabolized and eliminated. Another set of animals was implanted with electrodes and submitted to the same experimental protocol for assessment of drug-induced sleep-wake changes. Wistar male rats weighing 300-400 g. Sleep deprived rats required more trials to learn the task and still showed a performance deficit during test, except from those treated with 150 mg/kg of lithium, which also reduced the time spent in REM sleep during sleep recovery. Lithium reduced rapid eye movement sleep and prevented memory impairment induced by sleep deprivation. These results indicate that these phenomena may be related, but cause-effect relationship cannot be ascertained.

REM Sleep Behavior and Motor Findings in Parkinson's Disease: A Cross-sectional Analysis

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Abhimanyu Mahajan

2014-06-01

Full Text Available Background: Parkinson's disease (PD represents a major public health challenge that will only grow in our aging population. Understanding the connection between PD and associated prodromal conditions, such as rapid eye movement sleep behavioral disorder (RBD, is critical to identifying prevention strategies. However, the relationship between RBD and severity of motor findings in early PD is unknown. This study aims to examine this relationship. Methods: The study population consisted of 418 PD patients who completed the Movement Disorders Society‐United Parkinson's Disease Rating Scale (MDS‐UPDRS and rapid eye movement sleep (REM disorder questionnaires at the baseline visit of the Michael J. Fox's Parkinson's Progression Markers Initiative (PPMI. Cross‐sectional analysis was carried out to assess the association between REM Sleep Behavior Screening Questionnaire score and MDS UPDRS‐3 (motor score categories. Correlation with a higher score category was described as “worse motor findings”. A score of 5 on the REM disorder questionnaire was defined as predictive of RBD.Results: Out of the 418 PD patients, 113 (27.0% had RBD. With univariate logistic regression analysis, individuals with scores predictive of RBD were 1.66 times more likely to have worse motor findings (p = 0.028. Even with age, gender, and Geriatric Depression Scale scores taken into account, individuals with scores predictive of RBD were 1.69 times more likely to have worse motor findings (p = 0.025.Discussion: PD patients with RBD symptoms had worse motor findings than those unlikely to have RBD. This association provides further evidence for the relationship between RBD and PD.

Vocabulary learning benefits from REM after slow-wave sleep.

Science.gov (United States)

Batterink, Laura J; Westerberg, Carmen E; Paller, Ken A

2017-10-01

Memory reactivation during slow-wave sleep (SWS) influences the consolidation of recently acquired knowledge. This reactivation occurs spontaneously during sleep but can also be triggered by presenting learning-related cues, a technique known as targeted memory reactivation (TMR). Here we examined whether TMR can improve vocabulary learning. Participants learned the meanings of 60 novel words. Auditory cues for half the words were subsequently presented during SWS in an afternoon nap. Memory performance for cued versus uncued words did not differ at the group level but was systematically influenced by REM sleep duration. Participants who obtained relatively greater amounts of REM showed a significant benefit for cued relative to uncued words, whereas participants who obtained little or no REM demonstrated a significant effect in the opposite direction. We propose that REM after SWS may be critical for the consolidation of highly integrative memories, such as new vocabulary. Reactivation during SWS may allow newly encoded memories to be associated with other information, but this association can include disruptive linkages with pre-existing memories. Subsequent REM sleep may then be particularly beneficial for integrating new memories into appropriate pre-existing memory networks. These findings support the general proposition that memory storage benefits optimally from a cyclic succession of SWS and REM. Copyright © 2017 Elsevier Inc. All rights reserved.

Environmental risk factors for REM sleep behavior disorder

DEFF Research Database (Denmark)

Postuma, R B; Montplaisir, J Y; Pelletier, A

2012-01-01

Idiopathic REM sleep behavior disorder is a parasomnia characterized by dream enactment and is commonly a prediagnostic sign of parkinsonism and dementia. Since risk factors have not been defined, we initiated a multicenter case-control study to assess environmental and lifestyle risk factors...... for REM sleep behavior disorder....

REM sleep selectively prunes and maintains new synapses in development and learning.

Science.gov (United States)

Li, Wei; Ma, Lei; Yang, Guang; Gan, Wen-Biao

2017-03-01

The functions and underlying mechanisms of rapid eye movement (REM) sleep remain unclear. Here we show that REM sleep prunes newly formed postsynaptic dendritic spines of layer 5 pyramidal neurons in the mouse motor cortex during development and motor learning. This REM sleep-dependent elimination of new spines facilitates subsequent spine formation during development and when a new motor task is learned, indicating a role for REM sleep in pruning to balance the number of new spines formed over time. Moreover, REM sleep also strengthens and maintains newly formed spines, which are critical for neuronal circuit development and behavioral improvement after learning. We further show that dendritic calcium spikes arising during REM sleep are important for pruning and strengthening new spines. Together, these findings indicate that REM sleep has multifaceted functions in brain development, learning and memory consolidation by selectively eliminating and maintaining newly formed synapses via dendritic calcium spike-dependent mechanisms.

Family history of idiopathic REM behavior disorder

DEFF Research Database (Denmark)

Dauvilliers, Yves; Postuma, Ronald B; Ferini-Strambi, Luigi

2013-01-01

To compare the frequency of proxy-reported REM sleep behavior disorder (RBD) among relatives of patients with polysomnogram-diagnosed idiopathic RBD (iRBD) in comparison to controls using a large multicenter clinic-based cohort.......To compare the frequency of proxy-reported REM sleep behavior disorder (RBD) among relatives of patients with polysomnogram-diagnosed idiopathic RBD (iRBD) in comparison to controls using a large multicenter clinic-based cohort....

Daytime REM sleep affects emotional experience but not decision choices in moral dilemmas.

Science.gov (United States)

Cellini, Nicola; Lotto, Lorella; Pletti, Carolina; Sarlo, Michela

2017-09-11

Moral decision-making depends on the interaction between automatic emotional responses and rational cognitive control. A natural emotional regulator state seems to be sleep, in particular rapid eye movement (REM) sleep. We tested the impact of daytime sleep, either with or without REM, on moral decision. Sixty participants were presented with 12 sacrificial (6 Footbridge- and 6 Trolley-type) and 8 everyday-type moral dilemmas at 9 AM and at 5 PM. In sacrificial dilemmas, participants had to decide whether or not to kill one person to save more people (utilitarian choice), and to judge how morally acceptable the proposed choice was. In everyday-type dilemmas, participants had to decide whether to endorse moral violations involving dishonest behavior. At 12 PM, 40 participants took a 120-min nap (17 with REM and 23 with NREM only) while 20 participants remained awake. Mixed-model analysis revealed that participants judged the utilitarian choice as less morally acceptable in the afternoon, irrespective of sleep. We also observed a negative association between theta activity during REM and increased self-rated unpleasantness during moral decisions. Nevertheless, moral decision did not change across the day and between groups. These results suggest that although both time and REM sleep may affect the evaluation of a moral situation, these factors did not ultimately impact the individual moral choices.

Melanin-concentrating hormone (MCH: role in REM sleep and depression

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Pablo eTorterolo

2015-12-01

Full Text Available The melanin-concentrating hormone (MCH is a peptidergic neuromodulator synthesized by neurons of the lateral hypothalamus and incerto-hypothalamic area. MCHergic neurons project throughout the central nervous system, including areas such as the dorsal (DR and median (MR raphe nuclei, which are involved in the control of sleep and mood.Major Depression (MD is a prevalent psychiatric disease diagnosed on the basis of symptomatic criteria such as sadness or melancholia, guilt, irritability and anhedonia. A short REM sleep latency (i.e. the interval between sleep onset and the first REM sleep period, as well as an increase in the duration of REM sleep and the density of rapid-eye movements during this state, are considered important biological markers of depression. The fact that the greatest firing rate of MCHergic neurons occurs during REM sleep and that optogenetic stimulation of these neurons induces sleep, tends to indicate that MCH plays a critical role in the generation and maintenance of sleep, especially REM sleep. In addition, the acute microinjection of MCH into the DR promotes REM sleep, while immunoneutralization of this peptide within the DR decreases the time spent in this state. Moreover, microinjections of MCH into either the DR or MR promote a depressive-like behavior. In the DR, this effect is prevented by the systemic administration of antidepressant drugs (either fluoxetine or nortriptyline and blocked by the intra-DR microinjection of a specific MCH receptor antagonist. Using electrophysiological and microdialysis techniques we demonstrated also that MCH decreases the activity of serotonergic DR neurons.Therefore, there are substantive experimental data suggesting that the MCHergic system plays a role in the control of REM sleep and, in addition, in the pathophysiology of depression. Consequently, in the present report, we summarize and evaluate the current data and hypotheses related to the role of MCH in REM sleep and MD.

Automatic detection of REM sleep in subjects without atonia

DEFF Research Database (Denmark)

Kempfner, Jacob; Jennum, Poul; Nikolic, Miki

2012-01-01

Idiopathic Rapid-Rye-Movement (REM) sleep Behavior Disorder (iRBD) is a strong early marker of Parkinson's Disease and is characterized by REM sleep without atonia (RSWA) and increased phasic muscle activity. Current proposed methods for detecting RSWA assume the presence of a manually scored...... hypnogram. In this study a full automatic REM sleep detector, using the EOG and EEG channels, is proposed. Based on statistical features, combined with subject specific feature scaling and post-processing of the classifier output, it was possible to obtain an mean accuracy of 0.96 with a mean sensititvity...

REM Sleep Behavior Disorder and Prodromal Neurodegeneration - Where are We Headed?

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Ronald B. Postuma

2013-04-01

Full Text Available Rapid eye movement (REM sleep behavior disorder (RBD is characterized by loss of normal atonia during REM sleep, such that patients appear to act out their dreams. The most important implication of research into this area is that patients with idiopathic RBD are at very high risk of developing synucleinmediated neurodegenerative disease (Parkinson's disease [PD], dementia with Lewy bodies [DLB], and multiple system atrophy, with risk estimates that approximate 40–65% at 10 years. Thus, RBD disorder is a very strong feature of prodromal synucleinopathy. This provides several opportunities for future research. First, patients with REM sleep behavior disorder can be studied to test other predictors of disease, which could potentially be applied to the general population. These studies have demonstrated that olfactory loss, decreased color vision, slowing on quantitative motor testing, and abnormal substantia nigra neuroimaging findings can predict clinical synucleinopathy. Second, prospectively studying patients with RBD allows a completely unprecedented opportunity to directly evaluate patients as they transition into clinical neurodegenerative disease. Studies assessing progression of markers of neurodegeneration in prodromal PD are beginning to appear. Third, RBD are very promising subjects for neuroprotective therapy trials because they have a high risk of disease conversion with a sufficiently long latency, which provides an opportunity for early intervention. As RBD research expands, collaboration between centers will become increasingly essential.

Removal of ocular artifacts from the REM sleep EEG

NARCIS (Netherlands)

Waterman, D.; Woestenburg, J.C.; Elton, M.; Hofman, W.; Kok, A.

1992-01-01

The present report concerns the first study in which electrooculographic (EOG) contamination of electroencephalographic (EEG) recordings in rapid eye movement (REM) sleep is systematically investigated. Contamination of REM sleep EEG recordings in six subjects was evaluated in the frequency domain.

Brain prolactin is involved in stress-induced REM sleep rebound.

Science.gov (United States)

Machado, Ricardo Borges; Rocha, Murilo Ramos; Suchecki, Deborah

2017-03-01

REM sleep rebound is a common behavioural response to some stressors and represents an adaptive coping strategy. Animals submitted to multiple, intermittent, footshock stress (FS) sessions during 96h of REM sleep deprivation (REMSD) display increased REM sleep rebound (when compared to the only REMSD ones, without FS), which is correlated to high plasma prolactin levels. To investigate whether brain prolactin plays a role in stress-induced REM sleep rebound two experiments were carried out. In experiment 1, rats were either not sleep-deprived (NSD) or submitted to 96h of REMSD associated or not to FS and brains were evaluated for PRL immunoreactivity (PRL-ir) and determination of PRL concentrations in the lateral hypothalamus and dorsal raphe nucleus. In experiment 2, rats were implanted with cannulas in the dorsal raphe nucleus for prolactin infusion and were sleep-recorded. REMSD associated with FS increased PRL-ir and content in the lateral hypothalamus and all manipulations increased prolactin content in the dorsal raphe nucleus compared to the NSD group. Prolactin infusion in the dorsal raphe nucleus increased the time and length of REM sleep episodes 3h after the infusion until the end of the light phase of the day cycle. Based on these results we concluded that brain prolactin is a major mediator of stress-induced REMS. The effect of PRL infusion in the dorsal raphe nucleus is discussed in light of the existence of a bidirectional relationship between this hormone and serotonin as regulators of stress-induced REM sleep rebound. Copyright © 2016 Elsevier Inc. All rights reserved.

Noradrenaline from Locus Coeruleus Neurons Acts on Pedunculo-Pontine Neurons to Prevent REM Sleep and Induces Its Loss-Associated Effects in Rats.

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Khanday, Mudasir Ahmad; Somarajan, Bindu I; Mehta, Rachna; Mallick, Birendra Nath

2016-01-01

Normally, rapid eye movement sleep (REMS) does not appear during waking or non-REMS. Isolated, independent studies showed that elevated noradrenaline (NA) levels inhibit REMS and induce REMS loss-associated cytomolecular, cytomorphological, psychosomatic changes and associated symptoms. However, the source of NA and its target in the brain for REMS regulation and function in health and diseases remained to be confirmed in vivo . Using tyrosine hydroxylase (TH)-siRNA and virus-coated TH-shRNA in normal freely moving rats, we downregulated NA synthesis in locus coeruleus (LC) REM-OFF neurons in vivo . These TH-downregulated rats showed increased REMS, which was prevented by infusing NA into the pedunculo-pontine tegmentum (PPT), the site of REM-ON neurons, normal REMS returned after recovery. Moreover, unlike normal or control-siRNA- or shRNA-injected rats, upon REMS deprivation (REMSD) TH-downregulated rat brains did not show elevated Na-K ATPase (molecular changes) expression and activity. To the best of our knowledge, these are the first in vivo findings in an animal model confirming that NA from the LC REM-OFF neurons (1) acts on the PPT REM-ON neurons to prevent appearance of REMS, and (2) are responsible for inducing REMSD-associated molecular changes and symptoms. These observations clearly show neuro-physio-chemical mechanism of why normally REMS does not appear during waking. Also, that LC neurons are the primary source of NA, which in turn causes some, if not many, REMSD-associated symptoms and behavioral changes. The findings are proof-of-principle for the first time and hold potential to be exploited for confirmation toward treating REMS disorder and amelioration of REMS loss-associated symptoms in patients.

Risk evaluation and mitigation strategies (REMS): educating the prescriber.

Science.gov (United States)

Nicholson, Susan C; Peterson, Janet; Yektashenas, Behin

2012-02-01

The US FDA Amendments Act of 2007 was signed into law on 27 September 2007. A provision of this law granted the FDA new powers to enhance drug safety by requiring the pharmaceutical industry to develop Risk Evaluation and Mitigation Strategies (REMS). REMS are deemed necessary when a question exists as to whether the benefits of a drug outweigh its risks. REMS constitute a safety plan with several potential components, including a medication guide, a communication plan, elements to ensure safe use and an implementation system to help guide the prescribers, pharmacists and patients. This applies to existing drugs on the market, new drug applications (NDAs), abbreviated NDAs (generics) and biologics licence applications. REMS represent an 'upgrade' from previously required risk minimization action plans, based on the strengthening of FDA powers of authority and enforceability to incur monetary penalties against individuals representing the pharmaceutical industry who fail to comply. For illustrative purposes, we chose the drug romiplostim (Nplate®) to present an REMS, as all components were utilized to help assuage risks associated with the drug. Romiplostim is an FDA-approved drug used to treat thrombocytopenia in patients with chronic immune (idiopathic) thrombocytopenic purpura that has a significant adverse safety profile based on the risk of changes in bone marrow reticulin formation and bone marrow fibroses, and other associated risks. This review of current REMS policy is intended to provide the prescriber with a better understanding of current modalities in FDA-mandated drug safety programmes, which will impact day-to-day healthcare provider practices.

The Antarctic permafrost as a testbed for REMS (Rover Environmental Monitoring Station-Mars Science Laboratory)

Science.gov (United States)

Esteban, B.; Ramos, M.; Sebastián, E.; Armiens, C.; Gómez-Elvira, J.; Cabos, W.; de Pablo, M. A.

2009-04-01

two soil temperature plates based on Pt100 sensors are in close contact with the surface in the angle of view of the GT-REMS thermopiles. In this work, we present a preliminary analysis of the data obtained in the Antarctic field campaign 2008-2009. For the analysis we developed a theoretical model which is briefly outlined here. We also present the results of simulations carried out with the model and their validation against the antarctic data. Complementary to the Antarctic experiments, we carried out an experience with all the instruments during the last summer in the CAB-Spain which are also used in the analysis. Finally, we compare the results of the last polar and CAB experiments in order to check the improvements introduced in GT-REMS.

Respiration amplitude analysis for REM and NREM sleep classification

NARCIS (Netherlands)

Long, X.; Foussier, J.; Fonseca, P.; Haakma, R.; Aarts, R.M.

2013-01-01

In previous work, single-night polysomnography recordings (PSG) of respiratory effort and electrocardiogram (ECG) signals combined with actigraphy were used to classify sleep and wake states. In this study, we aim at classifying rapid-eye-movement (REM) and non-REM (NREM) sleep states. Besides the

Perifornical orexinergic neurons modulate REM sleep by influencing locus coeruleus neurons in rats.

Science.gov (United States)

Choudhary, R C; Khanday, M A; Mitra, A; Mallick, B N

2014-10-24

Activation of the orexin (OX)-ergic neurons in the perifornical (PeF) area has been reported to induce waking and reduce rapid eye movement sleep (REMS). The activities of OX-ergic neurons are maximum during active waking and they progressively reduce during non-REMS (NREMS) and REMS. Apparently, the locus coeruleus (LC) neurons also behave in a comparable manner as that of the OX-ergic neurons particularly in relation to waking and REMS. Further, as PeF OX-ergic neurons send dense projections to LC, we argued that the former could drive the LC neurons to modulate waking and REMS. Studies in freely moving normally behaving animals where simultaneously neuro-chemo-anatomo-physio-behavioral information could be deciphered would significantly strengthen our understanding on the regulation of REMS. Therefore, in this study in freely behaving chronically prepared rats we stimulated the PeF neurons without or with simultaneous blocking of specific subtypes of OX-ergic receptors in the LC while electrophysiological recording characterizing sleep-waking was continued. Single dose of glutamate stimulation as well as sustained mild electrical stimulation of PeF (both bilateral) significantly increased waking and reduced REMS as compared to baseline. Simultaneous application of OX-receptor1 (OX1R) antagonist bilaterally into the LC prevented PeF stimulation-induced REMS suppression. Also, the effect of electrical stimulation of the PeF was long lasting as compared to that of the glutamate stimulation. Further, sustained electrical stimulation significantly decreased both REMS duration as well as REMS frequency, while glutamate stimulation decreased REMS duration only. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Representation of the Self in REM and NREM Dreams

Science.gov (United States)

McNamara, Patrick; McLaren, Deirdre; Durso, Kate

2008-01-01

The authors hypothesized that representations of the Self (or the dreamer) in dreams would change systematically, from a prereflective form of Self to more complex forms, as a function of both age and sleep state (REM vs. non-REM). These hypotheses were partially confirmed. While the authors found that all the self-concept-related dream content indexes derived from the Hall/Van de Castle dream content scoring system did not differ significantly between the dreams of children and adults, adult Selves were more likely to engage in “successful” social interactions. The Self never acted as aggressor in NREM dream states and was almost always the befriender in friendly interactions in NREM dreams. Conversely, the REM-related dream Self preferred aggressive encounters. Our results suggests that while prereflective forms of Self are the norm in children’s dreams, two highly complex forms of Self emerge in REM and NREM dreams. PMID:19169371

Brainstem circuitry regulating phasic activation of trigeminal motoneurons during REM sleep.

Directory of Open Access Journals (Sweden)

Christelle Anaclet

2010-01-01

Full Text Available Rapid eye movement sleep (REMS is characterized by activation of the cortical and hippocampal electroencephalogram (EEG and atonia of non-respiratory muscles with superimposed phasic activity or twitching, particularly of cranial muscles such as those of the eye, tongue, face and jaw. While phasic activity is a characteristic feature of REMS, the neural substrates driving this activity remain unresolved. Here we investigated the neural circuits underlying masseter (jaw phasic activity during REMS. The trigeminal motor nucleus (Mo5, which controls masseter motor function, receives glutamatergic inputs mainly from the parvocellular reticular formation (PCRt, but also from the adjacent paramedian reticular area (PMnR. On the other hand, the Mo5 and PCRt do not receive direct input from the sublaterodorsal (SLD nucleus, a brainstem region critical for REMS atonia of postural muscles. We hypothesized that the PCRt-PMnR, but not the SLD, regulates masseter phasic activity during REMS.To test our hypothesis, we measured masseter electromyogram (EMG, neck muscle EMG, electrooculogram (EOG and EEG in rats with cell-body specific lesions of the SLD, PMnR, and PCRt. Bilateral lesions of the PMnR and rostral PCRt (rPCRt, but not the caudal PCRt or SLD, reduced and eliminated REMS phasic activity of the masseter, respectively. Lesions of the PMnR and rPCRt did not, however, alter the neck EMG or EOG. To determine if rPCRt neurons use glutamate to control masseter phasic movements, we selectively blocked glutamate release by rPCRt neurons using a Cre-lox mouse system. Genetic disruption of glutamate neurotransmission by rPCRt neurons blocked masseter phasic activity during REMS.These results indicate that (1 premotor glutamatergic neurons in the medullary rPCRt and PMnR are involved in generating phasic activity in the masseter muscles, but not phasic eye movements, during REMS; and (2 separate brainstem neural circuits control postural and cranial muscle

Increased Motor Activity During REM Sleep Is Linked with Dopamine Function in Idiopathic REM Sleep Behavior Disorder and Parkinson Disease

DEFF Research Database (Denmark)

Zoetmulder, Marielle; Nikolic, Miki; Biernat, Heidi B

2016-01-01

STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown......-FP-CIT uptake in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. CONCLUSIONS: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD....... the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. METHODS: 10 iRBD patients, 10 PD patients with PD, 10 PD patients...

Increased Motor Activity During REM Sleep Is Linked with Dopamine Function in Idiopathic REM Sleep Behaviour Disorder and Parkinson Disease

DEFF Research Database (Denmark)

Zoetmulder, Marielle; Nikolic, Miki; Biernat, Heidi

2016-01-01

STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown...... in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. CONCLUSIONS: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD....... the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. METHODS: 10 iRBD patients, 10 PD patients with PD, 10 PD patients...

Clinical and polysomnographic characteristics of patients with REM sleep disordered breathing

Directory of Open Access Journals (Sweden)

Cláudia Chaves Loureiro

2009-09-01

Full Text Available There is a 10–36% rate of obstructive sleep apnoea syndrome (OSAS associated with rapid eye movement (REM in the OSAS population. Prior studies have suggested an increased prevalence of psychiatric disorders and an effect of gender and age on these patients.Our aim was to study the clinical and polysomnograph (PSG characteristics of our patients with REM-related sleep disordered breathing (REM SDB.Inclusion criteria was the identification of REM SDB detected by PSG defined as apnea-hypopnea index (AHI in REM sleep ≥ 5 h, AHI in non-REM sleep (NREM ≤ 15 h and REM/NREM AHI ≥ 2.Several Sleep Disorders Questionnaire (SDQ version 1.02 parameters were analysed.The study comprised 19 patients with a mean age of 54.0 (SD ± 13.97, a mean BMI of 29.01 (SD ± 4.10 and a 0.58 female / male ratio. The mean Epworth Sleepiness Scale score was 12.74 (SD ± 4.86. Mean AHI was 9.16/h (SD 4.09; mean AHI in REM sleep 37.08/h (SD 25.87 and mean REM-AHI/NREM-AHI 8.86 (SD 8.63.The anxiety disorder rate was 33.3%; 44.4% in females, 16.7% in males.The average deep sleep was 20.7% (SD 10.42 and REM sleep 15.45% (SD 9.96, with a sleep efficiency of 85.3 (SD 8.70.No significant statistical correlation was found between the REM/NREM AHI index and anxiety symptoms, daytime sleepiness and sleep quality (REM and deep sleep percentages.These patients differ from the general OSAS population: on average, they are not obese, there are a greater number of females affected and they do not present a very significant diurnal hypersomnia. Reduced deep sleep and increased REM sleep were also present versus general population data, and sleep efficiency was just below the normal limit.Anxiety disorders were more prevalent in this group than described for the general population (3% and OSAS patients. Resumo: A síndroma de apneia obstrutiva do sono (SAOS associada ao sono REM tem uma incidência de 10–36% na

Visual hallucinations and pontine demyelination in a child: possible REM dissociation?

Science.gov (United States)

Vita, Maria Gabriella; Batocchi, Anna Paola; Dittoni, Serena; Losurdo, Anna; Cianfoni, Alessandro; Stefanini, Maria Chiara; Vollono, Catello; Della Marca, Giacomo; Mariotti, Paolo

2008-12-15

An 11 year-old-boy acutely developed complex visual and acoustic hallucinations. Hallucinations, consisting of visions of a threatening, evil character of the Harry Potter saga, persisted for 3 days. Neurological and psychiatric examinations were normal. Ictal EEG was negative. MRI documented 3 small areas of hyperintense signal in the brainstem, along the paramedian and lateral portions of pontine tegmentum, one of which showed post-contrast enhancement. These lesions were likely of inflammatory origin, and treatment with immunoglobulins was started. Polysomnography was normal, multiple sleep latency test showed a mean sleep latency of 8 minutes, with one sleep-onset REM period. The pontine tegmentum is responsible for REM sleep regulation, and contains definite "REM-on" and "REM-off" regions. The anatomical distribution of the lesions permits us to hypothesize that hallucinations in this boy were consequent to a transient impairment of REM sleep inhibitory mechanisms, with the appearance of dream-like hallucinations during wake.

Motivation and affect in REM sleep and the mentation reporting process.

Science.gov (United States)

Smith, Mark R; Antrobus, John S; Gordon, Evelyn; Tucker, Matthew A; Hirota, Yasutaka; Wamsley, Erin J; Ross, Lars; Doan, Tieu; Chaklader, Annie; Emery, Rebecca N

2004-09-01

Although the emotional and motivational characteristics of dreaming have figured prominently in folk and psychoanalytic conceptions of dream production, emotions have rarely been systematically studied, and motivation, never. Because emotions during sleep lack the somatic components of waking emotions, and they change as the sleeper awakens, their properties are difficult to assess. Recent evidence of limbic system activation during REM sleep suggests a basis in brain architecture for the interaction of motivational and cognitive properties in dreaming. Motivational and emotional content in REM and NREM laboratory mentation reports from 25 participants were compared. Motivational and emotional content was significantly greater in REM than NREM sleep, even after controlling for the greater word count of REM reports.

Validating severity of illness scoring systems in the prediction of outcomes in Staphylococcus aureus bacteremia.

Science.gov (United States)

Sharma, Mamta; Szpunar, Susan; Khatib, Riad

2013-08-01

Severity of illness scores are helpful in predicting mortality; however, no standardized scoring system has been validated in patients with Staphylococcus aureus bacteremia (SAB). The modified Rapid Emergency Medicine Score (REMS), the CURB-65 (confusion, urea, respiratory rate, blood pressure and age 65) and the Charlson weighted index of comorbidity (CWIC) were compared in predicting outcomes at the onset of SAB. All adult inpatients with SAB from July 15, 2008, to December 31, 2009, were prospectively assessed. The 3 scoring systems were applied: REMS, CURB-65 and CWIC. The end points were attributable and overall mortality. A total of 241 patients with SAB were reviewed during the study period. The all-cause mortality rate was 22.8% and attributable mortality 14.1%. Patients who died had higher mean CURB-65 score and REMS than those who lived, whereas the difference in the CWIC score was not significant. Two logistic regression models based on CURB-65 score or REMS, after controlling for CWIC, revealed that both scores were independent predictors of mortality, with an odds ratio of 3.38 (P < 0.0001) and 1.45 (P < 0.0001) for CURB-65 and REMS, respectively. Receiver operating characteristic analysis revealed that a cutoff point of 3.0 (CURB-65) and 6.0 (REMS) provided the highest sensitivity and specificity. The area under the curves for all-cause mortality were 0.832 and 0.806, and for attributable mortality 0.845 and 0.819, for CURB-65 and REMS, respectively. REMS and CURB-65 scores outperformed CWIC as predictors of mortality in SAB and may be effective in predicting the severity of illness at the onset of bacteremia.

Analysis of automated quantification of motor activity in REM sleep behaviour disorder

DEFF Research Database (Denmark)

Frandsen, Rune; Nikolic, Miki; Zoetmulder, Marielle

2015-01-01

Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by dream enactment and REM sleep without atonia. Atonia is evaluated on the basis of visual criteria, but there is a need for more objective, quantitative measurements. We aimed to define and optimize a method for establishing...... baseline and all other parameters in automatic quantifying submental motor activity during REM sleep. We analysed the electromyographic activity of the submental muscle in polysomnographs of 29 patients with idiopathic RBD (iRBD), 29 controls and 43 Parkinson's (PD) patients. Six adjustable parameters...... were validated on PD patients. Automatic baseline estimation improved characterization of atonia during REM sleep, as it eliminates inter/intra-observer variability and can be standardized across diagnostic centres. We found an optimized method for quantifying motor activity during REM sleep...

Effects of selective REM sleep deprivation on prefrontal gamma activity and executive functions.

Science.gov (United States)

Corsi-Cabrera, M; Rosales-Lagarde, A; del Río-Portilla, Y; Sifuentes-Ortega, R; Alcántara-Quintero, B

2015-05-01

Given that the dorsolateral prefrontal cortex is involved in executive functions and is deactivated and decoupled from posterior associative regions during REM sleep, that Gamma temporal coupling involved in information processing is enhanced during REM sleep, and that adult humans spend about 90 min of every 24h in REM sleep, it might be expected that REM sleep deprivation would modify Gamma temporal coupling and have a deteriorating effect on executive functions. We analyzed EEG Gamma activity and temporal coupling during implementation of a rule-guided task before and after REM sleep deprivation and its effect on verbal fluency, flexible thinking and selective attention. After two nights in the laboratory for adaptation, on the third night subjects (n=18) were randomly assigned to either selective REM sleep deprivation effectuated by awakening them at each REM sleep onset or, the same number of NREM sleep awakenings as a control for unspecific effects of sleep interruptions. Implementation of abstract rules to guide behavior required greater activation and synchronization of Gamma activity in the frontopolar regions after REM sleep reduction from 20.6% at baseline to just 3.93% of total sleep time. However, contrary to our hypothesis, both groups showed an overall improvement in executive task performance and no effect on their capacity to sustain selective attention. These results suggest that after one night of selective REM sleep deprivation executive functions can be compensated by increasing frontal activation and they still require the participation of supervisory control by frontopolar regions. Copyright © 2015 Elsevier B.V. All rights reserved.

Estimate of man-rem expenditures for a mature CANDU 600 MW(e) station

International Nuclear Information System (INIS)

Kuperman, I.

1978-08-01

In recent years, man-rem expenditures at operating stations have come under close scrutiny in order to reduce operating personnel dosage. This increased awareness has led to concerted efforts to improve station design and to improve operating procedures to achieve lower man-rem expenditures. This paper is intended to highlight design improvements that have been made in the CANDU 600 MW(e) design and to show how these improvements will reduce man-rem expenditures. Other considerations, such as station decontaminations of the primary heat transport system and the fuelling machines and stricter chemistry control are presently available to help reduce man-rem consumption. Also, station management operating policy should emphasize man-rem awareness. (author)

Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

Science.gov (United States)

Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

2017-08-01

Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

Antidepressants Increase REM Sleep Muscle Tone in Patients with and without REM Sleep Behavior Disorder.

Science.gov (United States)

McCarter, Stuart J; St Louis, Erik K; Sandness, David J; Arndt, Katlyn; Erickson, Maia; Tabatabai, Grace; Boeve, Bradley F; Silber, Michael H

2015-06-01

REM sleep behavior disorder (RBD) is associated with antidepressant treatment, especially in younger patients; but quantitative REM sleep without atonia (RSWA) analyses of psychiatric RBD patients remain limited. We analyzed RSWA in adults receiving antidepressants, with and without RBD. We comparatively analyzed visual, manual, and automated RSWA between RBD and control groups. RSWA metrics were compared between groups, and regression was used to explore associations with clinical variables. Tertiary-care sleep center. Participants included traditional RBD without antidepressant treatment (n = 30, 15 Parkinson disease [PD-RBD] and 15 idiopathic); psychiatric RBD receiving antidepressants (n = 30); and adults without RBD, including antidepressant-treated psychiatric (n = 30), untreated psychiatric (n = 15), and OSA (n = 60) controls. N/A. RSWA was highest in traditional and psychiatric RBD, intermediate in treated psychiatric controls, and lowest in untreated psychiatric and OSA controls (P sleep without atonia (RSWA) even without REM sleep behavior disorder (RBD), suggesting that antidepressants, not depression, promote RSWA. Differences in RSWA distribution and type were also seen, with higher anterior tibialis RSWA in antidepressant-treated patients and higher tonic RSWA in Parkinson disease-RBD patients, which could aid distinction between RBD subtypes. These findings suggest that antidepressants may mediate different RSWA mechanisms or, alternatively, that RSWA type and distribution evolve during progressive neurodegeneration. Further prospective RSWA analyses are necessary to clarify the relationships between antidepressant treatment, psychiatric disease, and RBD. © 2015 Associated Professional Sleep Societies, LLC.

In-vivo staging of pathology in REM sleep behaviour disorder

DEFF Research Database (Denmark)

Knudsen, Karoline; Fedorova, Tatyana D.; Hansen, Allan K.

2018-01-01

originating in the locus coeruleus, and 18F-dihydroxyphenylalanine (DOPA) PET to assess nigrostriatal dopamine storage capacity. For each imaging modality, we compared patients with idiopathic REM sleep behaviour disorder with previously published reference data of controls without neurological disorders...... or cognitive impairment and with symptomatic patients with Parkinson's disease. We assessed imaging data using one-way ANOVA corrected for multiple comparisons. Findings: Between June 3, 2016, and Dec 19, 2017, we recruited 22 consecutive patients with idiopathic REM sleep behaviour disorder to the study...... REM sleep behaviour disorder (pequal to that in diagnosed Parkinson's disease. These patients also showed noradrenergic...

REM sleep respiratory behaviours mental content in narcoleptic lucid dreamers.

Science.gov (United States)

Oudiette, Delphine; Dodet, Pauline; Ledard, Nahema; Artru, Emilie; Rachidi, Inès; Similowski, Thomas; Arnulf, Isabelle

2018-02-08

Breathing is irregular during rapid eye-movement (REM) sleep, whereas it is stable during non-REM sleep. Why this is so remains a mystery. We propose that irregular breathing has a cortical origin and reflects the mental content of dreams, which often accompany REM sleep. We tested 21 patients with narcolepsy who had the exceptional ability to lucid dream in REM sleep, a condition in which one is conscious of dreaming during the dream and can signal lucidity with an ocular code. Sleep and respiration were monitored during multiple naps. Participants were instructed to modify their dream scenario so that it involved vocalizations or an apnoea, -two behaviours that require a cortical control of ventilation when executed during wakefulness. Most participants (86%) were able to signal lucidity in at least one nap. In 50% of the lucid naps, we found a clear congruence between the dream report (e.g., diving under water) and the observed respiratory behaviour (e.g., central apnoea) and, in several cases, a preparatory breath before the respiratory behaviour. This suggests that the cortico-subcortical networks involved in voluntary respiratory movements are preserved during REM sleep and that breathing irregularities during this stage have a cortical/subcortical origin that reflects dream content.

Quantitative differences among EMG activities of muscles innervated by subpopulations of hypoglossal and upper spinal motoneurons during non-REM sleep - REM sleep transitions: a window on neural processes in the sleeping brain.

Science.gov (United States)

Rukhadze, I; Kamani, H; Kubin, L

2011-12-01

In the rat, a species widely used to study the neural mechanisms of sleep and motor control, lingual electromyographic activity (EMG) is minimal during non-rapid eye movement (non-REM) sleep and then phasic twitches gradually increase after the onset of REM sleep. To better characterize the central neural processes underlying this pattern, we quantified EMG of muscles innervated by distinct subpopulations of hypoglossal motoneurons and nuchal (N) EMG during transitions from non-REM sleep to REM sleep. In 8 chronically instrumented rats, we recorded cortical EEG, EMG at sites near the base of the tongue where genioglossal and intrinsic muscle fibers predominate (GG-I), EMG of the geniohyoid (GH) muscle, and N EMG. Sleep-wake states were identified and EMGs quantified relative to their mean levels in wakefulness in successive 10 s epochs. During non-REM sleep, the average EMG levels differed among the three muscles, with the order being N>GH>GG-I. During REM sleep, due to different magnitudes of phasic twitches, the order was reversed to GG-I>GH>N. GG-I and GH exhibited a gradual increase of twitching that peaked at 70-120 s after the onset of REM sleep and then declined if the REM sleep episode lasted longer. We propose that a common phasic excitatory generator impinges on motoneuron pools that innervate different muscles, but twitching magnitudes are different due to different levels of tonic motoneuronal hyperpolarization. We also propose that REM sleep episodes of average durations are terminated by intense activity of the central generator of phasic events, whereas long REM sleep episodes end as a result of a gradual waning of the tonic disfacilitatory and inhibitory processes.

Slow waves, sharp waves, ripples, and REM in sleeping dragons.

Science.gov (United States)

Shein-Idelson, Mark; Ondracek, Janie M; Liaw, Hua-Peng; Reiter, Sam; Laurent, Gilles

2016-04-29

Sleep has been described in animals ranging from worms to humans. Yet the electrophysiological characteristics of brain sleep, such as slow-wave (SW) and rapid eye movement (REM) activities, are thought to be restricted to mammals and birds. Recording from the brain of a lizard, the Australian dragon Pogona vitticeps, we identified SW and REM sleep patterns, thus pushing back the probable evolution of these dynamics at least to the emergence of amniotes. The SW and REM sleep patterns that we observed in lizards oscillated continuously for 6 to 10 hours with a period of ~80 seconds. The networks controlling SW-REM antagonism in amniotes may thus originate from a common, ancient oscillator circuit. Lizard SW dynamics closely resemble those observed in rodent hippocampal CA1, yet they originate from a brain area, the dorsal ventricular ridge, that has no obvious hodological similarity with the mammalian hippocampus. Copyright © 2016, American Association for the Advancement of Science.

Differential effects of non-REM and REM sleep on memory consolidation?

OpenAIRE

Ackermann Sandra; Rasch  Bjoern

2013-01-01

Sleep benefitsmemory consolidation. Previous theoretical accounts have proposed a differential role of slowwave sleep (SWS) rapid eye movement (REM) sleep and stage N2 sleep for different types of memories. For example the dual process hypothesis proposes that SWS is beneficial for declarative memories whereas REMsleep is important for consolidation of non declarative procedural and emotional memories. In fact numerous recent studies do provide further support for the crucial role of SWS (or ...

Development of a spherical neutron rem monitor

International Nuclear Information System (INIS)

Panchal, C.G.; Madhavi, V.; Bansode, P.Y.; Jakati, R.K.; Ghodgaonkar, M.D.; Desai, S.S.; Shaikh, A.M.; Sathian, V.

2007-01-01

A new neutron rem monitor based on spherical LINUS with the state of art electronic circuits has been designed in Electronics Division. This prototype instrument encompasses a spherical double polythene moderator to improve an isotropic response and a lead layer to extend its energy response compared to the conventional neutron rem monitors. A systematic testing and calibration of the energy and directional response of the prototype monitor have been carried out. Although the monitor is expected to perform satisfactorily upto an energy ∼ 55 MeV, at present its response has been tested upto 5 MeV. (author)

Reassessment of NRC's dollar per person-rem conversion factor policy

International Nuclear Information System (INIS)

1995-12-01

The US Nuclear Regulatory Commission (NRC) has completed a review and analysis of its dollar per person-rem conversion factor policy. As a result of this review, the NRC has decided to adopt a $2000 per person-rem conversion factor, subject it to present worth considerations, and limit its scope solely to health effects. This is in contrast to the previous policy and staff practice of using an undiscounted $1000 per person-rem conversion factor that served as a surrogate for all offsite consequences (health and offsite property). The policy shift has been incorporated in ''Regulatory Analysis Guidelines of the US Nuclear Regulatory Commission,'' NUREG/BR-0058, Revision 2, November 1995

Venlafaxine-induced REM sleep behavioral disorder presenting as two fractures

Directory of Open Access Journals (Sweden)

R. Ryan Williams

2017-10-01

Full Text Available Rapid eye movement (REM sleep behavioral disorder is characterized by the absence of muscular atonia during REM sleep. In this disorder, patients can violently act out their dreams, placing them at risk for traumatic fractures during these episodes. REM sleep behavioral disorder (RBD can be a sign of future neurodegenerative disease and has also been found to be a side effect of certain psychiatric medications. We present a case of venlafaxine-induced RBD in a 55 year old female who presented with a 13 year history of intermittent parasomnia and dream enactment in addition to a recent history of two fractures requiring intervention.

Venlafaxine-induced REM sleep behavioral disorder presenting as two fractures.

Science.gov (United States)

Ryan Williams, R; Sandigo, Gustavo

2017-10-01

Rapid eye movement (REM) sleep behavioral disorder is characterized by the absence of muscular atonia during REM sleep. In this disorder, patients can violently act out their dreams, placing them at risk for traumatic fractures during these episodes. REM sleep behavioral disorder (RBD) can be a sign of future neurodegenerative disease and has also been found to be a side effect of certain psychiatric medications. We present a case of venlafaxine-induced RBD in a 55 year old female who presented with a 13 year history of intermittent parasomnia and dream enactment in addition to a recent history of two fractures requiring intervention.

Quantitative assessment of isolated rapid eye movement (REM) sleep without atonia without clinical REM sleep behavior disorder: clinical and research implications.

Science.gov (United States)

Sasai-Sakuma, Taeko; Frauscher, Birgit; Mitterling, Thomas; Ehrmann, Laura; Gabelia, David; Brandauer, Elisabeth; Inoue, Yuichi; Poewe, Werner; Högl, Birgit

2014-09-01

Rapid eye movement (REM) sleep without atonia (RWA) is observed in some patients without a clinical history of REM sleep behavior disorder (RBD). It remains unknown whether these patients meet the refined quantitative electromyographic (EMG) criteria supporting a clinical RBD diagnosis. We quantitatively evaluated EMG activity and investigated its overnight distribution in patients with isolated qualitative RWA. Fifty participants with an incidental polysomnographic finding of RWA (isolated qualitative RWA) were included. Tonic, phasic, and 'any' EMG activity during REM sleep on PSG were quantified retrospectively. Referring to the quantitative cut-off values for a polysomnographic diagnosis of RBD, 7/50 (14%) and 6/50 (12%) of the patients showed phasic and 'any' EMG activity in the mentalis muscle above the respective cut-off values. No patient was above the cut-off value for tonic EMG activity or phasic EMG activity in the anterior tibialis muscles. Patients with RWA above the cut-off value showed higher amounts of RWA during later REM sleep periods. This is the first study showing that some subjects with incidental RWA meet the refined quantitative EMG criteria for a diagnosis of RBD. Future longitudinal studies must investigate whether this subgroup with isolated qualitative RWA is at an increased risk of developing fully expressed RBD and/or neurodegenerative disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing the dream-lag effect for REM and NREM stage 2 dreams.

Science.gov (United States)

Blagrove, Mark; Fouquet, Nathalie C; Henley-Einion, Josephine A; Pace-Schott, Edward F; Davies, Anna C; Neuschaffer, Jennifer L; Turnbull, Oliver H

2011-01-01

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5-7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.

Assessing the Dream-Lag Effect for REM and NREM Stage 2 Dreams

Science.gov (United States)

Blagrove, Mark; Fouquet, Nathalie C.; Henley-Einion, Josephine A.; Pace-Schott, Edward F.; Davies, Anna C.; Neuschaffer, Jennifer L.; Turnbull, Oliver H.

2011-01-01

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5–7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation. PMID:22046336

Assessing the dream-lag effect for REM and NREM stage 2 dreams.

Directory of Open Access Journals (Sweden)

Mark Blagrove

Full Text Available This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5-7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM and from non-Rapid Eye Movement Sleep (NREM. This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2 dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.

The spectrum of REM sleep-related episodes in children with type 1 narcolepsy.

Science.gov (United States)

Antelmi, Elena; Pizza, Fabio; Vandi, Stefano; Neccia, Giulia; Ferri, Raffaele; Bruni, Oliviero; Filardi, Marco; Cantalupo, Gaetano; Liguori, Rocco; Plazzi, Giuseppe

2017-06-01

Type 1 narcolepsy is a central hypersomnia due to the loss of hypocretin-producing neurons and characterized by cataplexy, excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep. In children, close to the disease onset, type 1 narcolepsy has peculiar clinical features with severe cataplexy and a complex admixture of movement disorders occurring while awake. Motor dyscontrol during sleep has never been systematically investigated. Suspecting that abnormal motor control might affect also sleep, we systematically analysed motor events recorded by means of video polysomnography in 40 children with type 1 narcolepsy (20 females; mean age 11.8 ± 2.6 years) and compared these data with those recorded in 22 age- and sex-matched healthy controls. Motor events were classified as elementary movements, if brief and non-purposeful and complex behaviours, if simulating purposeful behaviours. Complex behaviours occurring during REM sleep were further classified as 'classically-defined' and 'pantomime-like' REM sleep behaviour disorder episodes, based on their duration and on their pattern (i.e. brief and vivid-energetic in the first case, longer and with subcontinuous gesturing mimicking daily life activity in the second case). Elementary movements emerging either from non-REM or REM sleep were present in both groups, even if those emerging from REM sleep were more numerous in the group of patients. Conversely, complex behaviours could be detected only in children with type 1 narcolepsy and were observed in 13 patients, with six having 'classically-defined' REM sleep behaviour disorder episodes and seven having 'pantomime-like' REM sleep behaviour disorder episodes. Complex behaviours during REM sleep tended to recur in a stereotyped fashion for several times during the night, up to be almost continuous. Patients displaying a more severe motor dyscontrol during REM sleep had also more severe motor disorder during daytime (i

The hypocretins (orexins mediate the “phasic” components of REM sleep: A new hypothesis

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Pablo Torterolo

2014-03-01

The hypocretinergic neurons are active during wakefulness in conjunction with the presence of motor activity that occurs during survival-related behaviors. These neurons decrease their firing rate during non-REM sleep; however there is still controversy upon the activity and role of these neurons during REM sleep. Hence, in the present report we conducted a critical review of the literature of the hypocretinergic system during REM sleep, and hypothesize a possible role of this system in the generation of REM sleep.

Loss of Gnas imprinting differentially affects REM/NREM sleep and cognition in mice.

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Glenda Lassi

Full Text Available It has been suggested that imprinted genes are important in the regulation of sleep. However, the fundamental question of whether genomic imprinting has a role in sleep has remained elusive up to now. In this work we show that REM and NREM sleep states are differentially modulated by the maternally expressed imprinted gene Gnas. In particular, in mice with loss of imprinting of Gnas, NREM and complex cognitive processes are enhanced while REM and REM-linked behaviors are inhibited. This is the first demonstration that a specific overexpression of an imprinted gene affects sleep states and related complex behavioral traits. Furthermore, in parallel to the Gnas overexpression, we have observed an overexpression of Ucp1 in interscapular brown adipose tissue (BAT and a significant increase in thermoregulation that may account for the REM/NREM sleep phenotypes. We conclude that there must be significant evolutionary advantages in the monoallelic expression of Gnas for REM sleep and for the consolidation of REM-dependent memories. Conversely, biallelic expression of Gnas reinforces slow wave activity in NREM sleep, and this results in a reduction of uncertainty in temporal decision-making processes.

Localization of rem2 in the central nervous system of the adult rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Downs, Anna G; Scholles, Katie R; Hollis, David M

2016-12-01

Rem2 is member of the RGK (Rem, Rad, and Gem/Kir) subfamily of the Ras superfamily of GTP binding proteins known to influence Ca 2+ entry into the cell. In addition, Rem2, which is found at high levels in the vertebrate brain, is also implicated in cell proliferation and synapse formation. Though the specific, regional localization of Rem2 in the adult mammalian central nervous system has been well-described, such information is lacking in other vertebrates. Rem2 is involved in neuronal processes where the capacities between adults of different vertebrate classes vary. Thus, we sought to localize the rem2 gene in the central nervous system of an adult anamniotic vertebrate, the rainbow trout (Oncorhynchus mykiss). In situ hybridization using a digoxigenin (DIG)-labeled RNA probe was used to identify the regional distribution of rem2 expression throughout the trout central nervous system, while real-time polymerase chain reaction (rtPCR) further supported these findings. Based on in situ hybridization, the regional distribution of rem2 occurred within each major subdivision of the brain and included large populations of rem2 expressing cells in the dorsal telencephalon of the cerebrum, the internal cellular layer of the olfactory bulb, and the optic tectum of the midbrain. In contrast, no rem2 expressing cells were resolved within the cerebellum. These results were corroborated by rtPCR, where differential rem2 expression occurred between the major subdivisions assayed with the highest levels being found in the cerebrum, while it was nearly absent in the cerebellum. These data indicate that rem2 gene expression is broadly distributed and likely influences diverse functions in the adult fish central nervous system. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermophysical Properties Along Curiosity's Traverse in Gale Crater, Mars, Derived from the REMS Ground Temperature Sensor

Science.gov (United States)

Vasavada, Ashwin R.; Piqueux, Sylvain; Lewis, Kevin W.; Lemmon, Mark T.; Smith, Michael Doyle

2016-01-01

The REMS instrument onboard the Mars Science Laboratory rover, Curiosity, has measured ground temperature nearly continuously at hourly intervals for two Mars years. Coverage of the entire diurnal cycle at 1 Hz is available every few martian days. We compare these measurements with predictions of surface atmosphere thermal models to derive the apparent thermal inertia and thermally derived albedo along the rovers traverse after accounting for the radiative effects of atmospheric water ice during fall and winter, as is necessary to match the measured seasonal trend. The REMS measurements can distinguish between active sand, other loose materials, mudstone, and sandstone based on their thermophysical properties. However, the apparent thermal inertias of bedrock dominated surfaces [approx. 350-550 J m(exp. -2) K(exp. -1 s(exp. -1/2 )] are lower than expected. We use rover imagery and the detailed shape of the diurnal ground temperature curve to explore whether lateral or vertical heterogeneity in the surface materials within the sensor footprint might explain the low inertias. We find that the bedrock component of the surface can have a thermal inertia as high as 650-1700 J m(exp. -2) K(exp. -1) s(exp. -1/2) for mudstone sites and approx. 700 J m(exp. -2) K(exp. -1) s(exp. - 1/2) for sandstone sites in models runs that include lateral and vertical mixing. Although the results of our forward modeling approach may be non-unique, they demonstrate the potential to extract information about lateral and vertical variations in thermophysical properties from temporally resolved measurements of ground temperature.

REM Sleep Behavior Disorder and Narcoleptic Features in Anti–Ma2-associated Encephalitis

Science.gov (United States)

Compta, Yaroslau; Iranzo, Alex; Santamaría, Joan; Casamitjana, Roser; Graus, Francesc

2007-01-01

A 69-year-old man with anti-Ma2 paraneoplastic encephalitis presented with subacute onset of severe hypersomnia, memory loss, parkinsonism, and gaze palsy. A brain magnetic resonance imaging study showed bilateral damage in the dorsolateral midbrain, amygdala, and paramedian thalami. Videopolysomnography disclosed rapid eye movement (REM) sleep behavior disorder, and a Multiple Sleep Latency Test showed a mean sleep latency of 7 minutes and 4 sleep-onset REM periods. The level of hypocretin-1 in the cerebrospinal fluid was low (49 pg/mL). This observation illustrates that REM sleep behavior disorder and narcoleptic features are 2 REM-sleep abnormalities that (1) may share the same autoimmune-mediated origin affecting the brainstem, limbic, and diencephalic structures and (2) may occur in the setting of the paraneoplastic anti–Ma2-associated encephalitis. Citation: Compta Y; Iranzo A; Santamaría J et al. REM Sleep Behavior Disorder and Narcoleptic Features in Anti–Ma2-associated Encephalitis. SLEEP 2007;30(6):767-769. PMID:17580598

Analysis of the environmental conditions at Gale Crater from MSL/REMS measurements

Energy Technology Data Exchange (ETDEWEB)

Martinez, G.; Torre-Juarez, M. de la; Vicente-Retortillo, A.; Kemppinen, O.; Renno, N.; Lemmon, M.

2016-07-01

The environmental conditions at Gale Crater during the first 1160 sols of the Mars Science Laboratory (MSL) mission are assessed using measurements taken by the Rover Environmental Monitoring Station (REMS) on-board the MSL Curiosity rover. REMS is a suite of sensors developed to assess the environmental conditions along the rover traverse. In particular, REMS has been measuring atmospheric pressure, atmospheric and ground temperature, relative humidity, UV radiation flux and wind speed. Here we analyze processed data with the highest confidence possible of atmospheric pressure, atmospheric and ground temperature and relative humidity. In addition, we estimate the daily UV irradiation at the surface of Gale Crater using dust opacity values derived from the Mastcam instrument. REMS is still in operation, but it has already provided the most comprehensive coverage of surface environmental conditions recorded by a spacecraft landed on Mars. (Author)

CAN NON-REM SLEEP BE DEPRESSOGENIC

NARCIS (Netherlands)

BEERSMA, DGM; VANDENHOOFDAKKER, RH

Sleep and mood are clearly interrelated in major depression, as shown by the antidepressive effects of various experiments, such as total sleep deprivation, partial sleep deprivation, REM sleep deprivation, and temporal shifts of the sleep period. The prevailing hypotheses explaining these effects

Can non-REM sleep be depressogenic?

NARCIS (Netherlands)

Beersma, Domien G.M.; Hoofdakker, Rutger H. van den

1992-01-01

Sleep and mood are clearly interrelated in major depression, as shown by the antidepressive effects of various experiments, such as total sleep deprivation, partial sleep deprivation, REM sleep deprivation, and temporal shifts of the sleep period. The prevailing hypotheses explaining these effects

Ventromedial medulla inhibitory neuron inactivation induces REM sleep without atonia and REM sleep behavior disorder.

Science.gov (United States)

Valencia Garcia, Sara; Brischoux, Frédéric; Clément, Olivier; Libourel, Paul-Antoine; Arthaud, Sébastien; Lazarus, Michael; Luppi, Pierre-Hervé; Fort, Patrice

2018-02-05

Despite decades of research, there is a persistent debate regarding the localization of GABA/glycine neurons responsible for hyperpolarizing somatic motoneurons during paradoxical (or REM) sleep (PS), resulting in the loss of muscle tone during this sleep state. Combining complementary neuroanatomical approaches in rats, we first show that these inhibitory neurons are localized within the ventromedial medulla (vmM) rather than within the spinal cord. We then demonstrate their functional role in PS expression through local injections of adeno-associated virus carrying specific short-hairpin RNA in order to chronically impair inhibitory neurotransmission from vmM. After such selective genetic inactivation, rats display PS without atonia associated with abnormal and violent motor activity, concomitant with a small reduction of daily PS quantity. These symptoms closely mimic human REM sleep behavior disorder (RBD), a prodromal parasomnia of synucleinopathies. Our findings demonstrate the crucial role of GABA/glycine inhibitory vmM neurons in muscle atonia during PS and highlight a candidate brain region that can be susceptible to α-synuclein-dependent degeneration in RBD patients.

Selective REM-sleep deprivation does not diminish emotional memory consolidation in young healthy subjects.

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Morgenthaler, Jarste; Wiesner, Christian D; Hinze, Karoline; Abels, Lena C; Prehn-Kristensen, Alexander; Göder, Robert

2014-01-01

Sleep enhances memory consolidation and it has been hypothesized that rapid eye movement (REM) sleep in particular facilitates the consolidation of emotional memory. The aim of this study was to investigate this hypothesis using selective REM-sleep deprivation. We used a recognition memory task in which participants were shown negative and neutral pictures. Participants (N=29 healthy medical students) were separated into two groups (undisturbed sleep and selective REM-sleep deprived). Both groups also worked on the memory task in a wake condition. Recognition accuracy was significantly better for negative than for neutral stimuli and better after the sleep than the wake condition. There was, however, no difference in the recognition accuracy (neutral and emotional) between the groups. In summary, our data suggest that REM-sleep deprivation was successful and that the resulting reduction of REM-sleep had no influence on memory consolidation whatsoever.

Management of REM sleep behavior disorder: An evidence based review.

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Devnani, Preeti; Fernandes, Racheal

2015-01-01

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream enactment behavior resulting from a loss of REM skeletal muscle atonia. The neurobiology of REM sleep and the characteristic features of REM atonia have an important basis for understanding the aggravating etiologies the proposed pharmacological interventions in its management. This review outlines the evidence for behavioral and therapeutic measures along with evidence-based guidelines for their implementation, impact on falls, and effect on polysomnography (PSG) while highlighting the non-motor, autonomic, and cognitive impact of this entity. PubMed databases were reviewed upto May 2013 in peer-reviewed scientific literature regarding the pathophysiology and management of RBD in adults. The literature was graded according to the Oxford centre of evidence-based Medicine Levels. An early intervention that helps prevent consequences such as falls and provides a base for intervention with neuroprotective mechanisms and allocates a unique platform that RBD portrays with its high risk of disease conversion with a sufficiently long latency. RBD provides a unique platform with its high risk of disease conversion with a sufficiently long latency, providing an opportunity for early intervention both to prevent consequences such as falls and provide a base for intervention with neuroprotective mechanisms.

Management of REM sleep behavior disorder: An evidence based review

Directory of Open Access Journals (Sweden)

Preeti Devnani

2015-01-01

Full Text Available Rapid eye movement (REM sleep behavior disorder (RBD is characterized by dream enactment behavior resulting from a loss of REM skeletal muscle atonia. The neurobiology of REM sleep and the characteristic features of REM atonia have an important basis for understanding the aggravating etiologies the proposed pharmacological interventions in its management. This review outlines the evidence for behavioral and therapeutic measures along with evidence-based guidelines for their implementation, impact on falls, and effect on polysomnography (PSG while highlighting the non-motor, autonomic, and cognitive impact of this entity. PubMed databases were reviewed upto May 2013 in peer-reviewed scientific literature regarding the pathophysiology and management of RBD in adults. The literature was graded according to the Oxford centre of evidence-based Medicine Levels. An early intervention that helps prevent consequences such as falls and provides a base for intervention with neuroprotective mechanisms and allocates a unique platform that RBD portrays with its high risk of disease conversion with a sufficiently long latency. RBD provides a unique platform with its high risk of disease conversion with a sufficiently long latency, providing an opportunity for early intervention both to prevent consequences such as falls and provide a base for intervention with neuroprotective mechanisms.

Predicting early cognitive decline in newly-diagnosed Parkinson's patients: A practical model.

Science.gov (United States)

Hogue, Olivia; Fernandez, Hubert H; Floden, Darlene P

2018-06-19

To create a multivariable model to predict early cognitive decline among de novo patients with Parkinson's disease, using brief, inexpensive assessments that are easily incorporated into clinical flow. Data for 351 drug-naïve patients diagnosed with idiopathic Parkinson's disease were obtained from the Parkinson's Progression Markers Initiative. Baseline demographic, disease history, motor, and non-motor features were considered as candidate predictors. Best subsets selection was used to determine the multivariable baseline symptom profile that most accurately predicted individual cognitive decline within three years. Eleven per cent of the sample experienced cognitive decline. The final logistic regression model predicting decline included five baseline variables: verbal memory retention, right-sided bradykinesia, years of education, subjective report of cognitive impairment, and REM behavior disorder. Model discrimination was good (optimism-adjusted concordance index = .749). The associated nomogram provides a tool to determine individual patient risk of meaningful cognitive change in the early stages of the disease. Through the consideration of easily-implemented or routinely-gathered assessments, we have identified a multidimensional baseline profile and created a convenient, inexpensive tool to predict cognitive decline in the earliest stages of Parkinson's disease. The use of this tool would generate prediction at the individual level, allowing clinicians to tailor medical management for each patient and identify at-risk patients for clinical trials aimed at disease modifying therapies. Copyright © 2018. Published by Elsevier Ltd.

Sleep stability and transitions in patients with idiopathic REM sleep behavior disorder and patients with Parkinson's disease

DEFF Research Database (Denmark)

Christensen, Julie Anja Engelhard; Jennum, Poul; Koch, Henriette

2016-01-01

Objective: Patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) are at high risk of developing Parkinson's disease (PD). As wake/sleep-regulation is thought to involve neurons located in the brainstem and hypothalamic areas, we hypothesize that the neurodegeneration in i......RBD/PD is likely to affect wake/sleep and REM/non-REM (NREM) sleep transitions. Methods: We determined the frequency of wake/sleep and REM/NREM sleep transitions and the stability of wake (W), REM and NREM sleep as measured by polysomnography (PSG) in 27 patients with PD, 23 patients with iRBD, 25 patients...... with periodic leg movement disorder (PLMD) and 23 controls. Measures were computed based on manual scorings and data-driven labeled sleep staging. Results: Patients with PD showed significantly lower REM stability than controls and patients with PLMD. Patients with iRBD had significantly lower REM stability...

REM sleep behavior disorder and narcoleptic features in anti-Ma2-associated encephalitis.

Science.gov (United States)

Compta, Yaroslau; Iranzo, Alex; Santamaría, Joan; Casamitjana, Roser; Graus, Francesc

2007-06-01

A 69-year-old man with anti-Ma2 paraneoplastic encephalitis presented with subacute onset of severe hypersomnia, memory loss, parkinsonism, and gaze palsy. A brain magnetic resonance imaging study showed bilateral damage in the dorsolateral midbrain, amygdala, and paramedian thalami. Videopolysomnography disclosed rapid eye movement (REM) sleep behavior disorder, and a Multiple Sleep Latency Test showed a mean sleep latency of 7 minutes and 4 sleep-onset REM periods. The level of hypocretin-1 in the cerebrospinal fluid was low (49 pg/mL). This observation illustrates that REM sleep behavior disorder and narcoleptic features are 2 REM-sleep abnormalities that (1) may share the same autoimmune-mediated origin affecting the brainstem, limbic, and diencephalic structures and (2) may occur in the setting of the paraneoplastic anti-Ma2-associated encephalitis.

Design and analysis of a model predictive controller for active queue management.

Science.gov (United States)

Wang, Ping; Chen, Hong; Yang, Xiaoping; Ma, Yan

2012-01-01

Model predictive (MP) control as a novel active queue management (AQM) algorithm in dynamic computer networks is proposed. According to the predicted future queue length in the data buffer, early packets at the router are dropped reasonably by the MPAQM controller so that the queue length reaches the desired value with minimal tracking error. The drop probability is obtained by optimizing the network performance. Further, randomized algorithms are applied to analyze the robustness of MPAQM successfully, and also to provide the stability domain of systems with uncertain network parameters. The performances of MPAQM are evaluated through a series of simulations in NS2. The simulation results show that the MPAQM algorithm outperforms RED, PI, and REM algorithms in terms of stability, disturbance rejection, and robustness. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Characteristic comparison of triglyceride-rich remnant lipoprotein measurement between a new homogenous assay (RemL-C and a conventional immunoseparation method (RLP-C

Directory of Open Access Journals (Sweden)

Saikawa Shinichi

2008-05-01

Full Text Available Abstract Background Increased serum remnant lipoproteins are supposed to predict cardiovascular disease in addition to increased LDL. A new homogenous assay for remnant lipoprotein-cholesterol (RemL-C has been developed as an alternative to remnant-like particle-cholesterol (RLP-C, an immunoseparation assay, widely used for the measurement of remnant lipoprotein cholesterol. Methods We evaluated the correlations and data validation between the 2 assays in 83 subjects (49 men and 34 women without diabetes, hypertension and medications for hyperlipidemia, diabetes, and hypertension, and investigated the characteristics of remnant lipoproteins obtained by the two methods (RLP-C and RemL-C and their relationships with IDL-cholesterol determined by our developed HPLC method. Results A positive correlation was significantly found between the two methods (r = 0.853, 95%CI 0.781–0.903, p RLP-C level. RemL-C (r = 0.339, 95%CI 0.152–0.903; p = 0.0005 significantly correlated with IDL-cholesterol, but not RLP-C (r = 0.17, 95%CI -0.047–0.372; p = 0.1237 in all the samples (n = 83. Conclusion These results suggest that there is generally a significant correlation between RemL-C and RLP-C. However, RemL-C assay is likely to reflect IDL more closely than RLP-C.

Sleep stability and transitions in patients with idiopathic REM sleep behavior disorder and patients with Parkinson's disease.

Science.gov (United States)

Christensen, Julie Anja Engelhard; Jennum, Poul; Koch, Henriette; Frandsen, Rune; Zoetmulder, Marielle; Arvastson, Lars; Christensen, Søren Rahn; Sorensen, Helge Bjarrup Dissing

2016-01-01

Patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) are at high risk of developing Parkinson's disease (PD). As wake/sleep-regulation is thought to involve neurons located in the brainstem and hypothalamic areas, we hypothesize that the neurodegeneration in iRBD/PD is likely to affect wake/sleep and REM/non-REM (NREM) sleep transitions. We determined the frequency of wake/sleep and REM/NREM sleep transitions and the stability of wake (W), REM and NREM sleep as measured by polysomnography (PSG) in 27 patients with PD, 23 patients with iRBD, 25 patients with periodic leg movement disorder (PLMD) and 23 controls. Measures were computed based on manual scorings and data-driven labeled sleep staging. Patients with PD showed significantly lower REM stability than controls and patients with PLMD. Patients with iRBD had significantly lower REM stability compared with controls. Patients with PD and RBD showed significantly lower NREM stability and significantly more REM/NREM transitions than controls. We conclude that W, NREM and REM stability and transitions are progressively affected in iRBD and PD, probably reflecting the successive involvement of brain stem areas from early on in the disease. Sleep stability and transitions determined by a data-driven approach could support the evaluation of iRBD and PD patients. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Evaluation of energy response of neutron rem monitor applied to high-energy accelerator facilities

Energy Technology Data Exchange (ETDEWEB)

Nakane, Yoshihiro; Harada, Yasunori; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

2003-03-01

A neutron rem monitor was newly developed for applying to the high-intensity proton accelerator facility (J-PARC) that is under construction as a joint project between the Japan Atomic Energy Research Institute and the High Energy Accelerator Research Organization. To measure the dose rate accurately for wide energy range of neutrons from thermal to high-energy region, the neutron rem monitor was fabricated by adding a lead breeder layer to a conventional neutron rem monitor. The energy response of the monitor was evaluated by using neutron transport calculations for the energy range from thermal to 150 MeV. For verifying the results, the response was measured at neutron fields for the energy range from thermal to 65 MeV. The comparisons between the energy response and dose conversion coefficients show that the newly developed neutron rem monitor has a good performance in energy response up to 150 MeV, suggesting that the present study offered prospects of a practical fabrication of the rem monitor applicable to the high intensity proton accelerator facility. (author)

A moderate increase of physiological CO2 in a critical range during stable NREM sleep episode: A potential gateway to REM sleep

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Vibha eMadan

2012-02-01

Full Text Available Sleep is characterized as rapid eye movement (REM and non-rapid eye movement (NREM sleep. Studies suggest that wake-related neurons in the basal forebrain, posterior hypothalamus and brainstem and NREM sleep-related neurons in the anterior-hypothalamic area inhibit each other, thus alternating sleep-wakefulness. Similarly, pontine REM-ON and REM-OFF neurons reciprocally inhibit each other for REM sleep modulation. It has been proposed that inhibition of locus coeruleus (LC REM-OFF neurons is pre-requisite for REM sleep genesis, but it remains ambiguous how REM-OFF neurons are hyperpolarized at REM sleep onset. The frequency of breathing pattern remains high during wake, slows down during NREM sleep but further escalates during REM sleep. As a result, brain CO2 level increases during NREM sleep, which may alter REM sleep manifestation. It has been reported that hypocapnia decreases REM sleep while hypercapnia increases REM sleep periods. The groups of brainstem chemosensory neurons, including those present in LC, sense the alteration in CO2 level and respond accordingly. For example; one group of LC neurons depolarize while other hyperpolarize during hypercapnia. In another group, hypercapnia initially depolarizes but later hyperpolarizes LC neurons. Besides chemosensory functions, LC’s REM-OFF neurons are an integral part of REM sleep executive machinery. We reason that increased CO2 level during a stable NREM sleep period may hyperpolarize LC neurons including REM-OFF, which may help initiate REM sleep. We propose that REM sleep might act as a sentinel to help maintain normal CO2 level for unperturbed sleep.

REM-3D Reference Datasets: Reconciling large and diverse compilations of travel-time observations

Science.gov (United States)

Moulik, P.; Lekic, V.; Romanowicz, B. A.

2017-12-01

A three-dimensional Reference Earth model (REM-3D) should ideally represent the consensus view of long-wavelength heterogeneity in the Earth's mantle through the joint modeling of large and diverse seismological datasets. This requires reconciliation of datasets obtained using various methodologies and identification of consistent features. The goal of REM-3D datasets is to provide a quality-controlled and comprehensive set of seismic observations that would not only enable construction of REM-3D, but also allow identification of outliers and assist in more detailed studies of heterogeneity. The community response to data solicitation has been enthusiastic with several groups across the world contributing recent measurements of normal modes, (fundamental mode and overtone) surface waves, and body waves. We present results from ongoing work with body and surface wave datasets analyzed in consultation with a Reference Dataset Working Group. We have formulated procedures for reconciling travel-time datasets that include: (1) quality control for salvaging missing metadata; (2) identification of and reasons for discrepant measurements; (3) homogenization of coverage through the construction of summary rays; and (4) inversions of structure at various wavelengths to evaluate inter-dataset consistency. In consultation with the Reference Dataset Working Group, we retrieved the station and earthquake metadata in several legacy compilations and codified several guidelines that would facilitate easy storage and reproducibility. We find strong agreement between the dispersion measurements of fundamental-mode Rayleigh waves, particularly when made using supervised techniques. The agreement deteriorates substantially in surface-wave overtones, for which discrepancies vary with frequency and overtone number. A half-cycle band of discrepancies is attributed to reversed instrument polarities at a limited number of stations, which are not reflected in the instrument response history

The effect of selective REM-sleep deprivation on the consolidation and affective evaluation of emotional memories.

Science.gov (United States)

Wiesner, Christian D; Pulst, Julika; Krause, Fanny; Elsner, Marike; Baving, Lioba; Pedersen, Anya; Prehn-Kristensen, Alexander; Göder, Robert

2015-07-01

Emotion boosts the consolidation of events in the declarative memory system. Rapid eye movement (REM) sleep is believed to foster the memory consolidation of emotional events. On the other hand, REM sleep is assumed to reduce the emotional tone of the memory. Here, we investigated the effect of selective REM-sleep deprivation, SWS deprivation, or wake on the affective evaluation and consolidation of emotional and neutral pictures. Prior to an 9-h retention interval, sixty-two healthy participants (23.5 ± 2.5 years, 32 female, 30 male) learned and rated their affect to 80 neutral and 80 emotionally negative pictures. Despite rigorous deprivation of REM sleep or SWS, the residual sleep fostered the consolidation of neutral and negative pictures. Furthermore, emotional arousal helped to memorize the pictures. The better consolidation of negative pictures compared to neutral ones was most pronounced in the SWS-deprived group where a normal amount of REM sleep was present. This emotional memory bias correlated with REM sleep only in the SWS-deprived group. Furthermore, emotional arousal to the pictures decreased over time, but neither sleep nor wake had any differential effect. Neither the comparison of the affective ratings (arousal, valence) during encoding and recognition, nor the affective ratings of the recognized targets and rejected distractors supported the hypothesis that REM sleep dampens the emotional reaction to remembered stimuli. The data suggest that REM sleep fosters the consolidation of emotional memories but has no effect on the affective evaluation of the remembered contents. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Functional role of diverse changes in sympathetic nerve activity in regulating arterial pressure during REM sleep.

Science.gov (United States)

Yoshimoto, Misa; Yoshida, Ikue; Miki, Kenju

2011-08-01

This study aimed to investigate whether REM sleep evoked diverse changes in sympathetic outflows and, if so, to elucidate why REM sleep evokes diverse changes in sympathetic outflows. Male Wistar rats were chronically implanted with electrodes to measure renal (RSNA) and lumbar sympathetic nerve activity (LSNA), electroencephalogram, electromyogram, and electrocardiogram, and catheters to measure systemic arterial and central venous pressure; these parameters were measured simultaneously and continuously during the sleep-awake cycle in the same rat. REM sleep resulted in a step reduction in RNSA by 36.1% ± 2.7% (P sleep. In contrast to REM sleep, RSNA, LSNA, systemic arterial pressure, and heart rate increased in a unidirectional manner associated with increases in physical activity levels in the order from NREM sleep, quiet awake, moving, and grooming state. Thus, the relationship between RSNA vs. LSNA and systemic arterial pressure vs. heart rate observed during REM sleep was dissociated compared with that obtained during the other behavioral states. It is suggested that the diverse changes in sympathetic outflows during REM sleep may be needed to increase systemic arterial pressure by balancing vascular resistance between muscles and vegetative organs without depending on the heart.

Comorbidity and medication in REM sleep behavior disorder

DEFF Research Database (Denmark)

Frauscher, Birgit; Jennum, Poul; Ju, Yo-El S

2014-01-01

OBJECTIVE: This controlled study investigated associations between comorbidity and medication in patients with polysomnographically confirmed idiopathic REM sleep behavior disorder (iRBD), using a large multicenter clinic-based cohort. METHODS: Data of a self-administered questionnaire...

Slow wave and REM sleep deprivation effects on explicit and implicit memory during sleep.

Science.gov (United States)

Casey, Sarah J; Solomons, Luke C; Steier, Joerg; Kabra, Neeraj; Burnside, Anna; Pengo, Martino F; Moxham, John; Goldstein, Laura H; Kopelman, Michael D

2016-11-01

It has been debated whether different stages in the human sleep cycle preferentially mediate the consolidation of explicit and implicit memories, or whether all of the stages in succession are necessary for optimal consolidation. Here we investigated whether the selective deprivation of slow wave sleep (SWS) or rapid eye movement (REM) sleep over an entire night would have a specific effect on consolidation in explicit and implicit memory tasks. Participants completed a set of explicit and implicit memory tasks at night, prior to sleep. They had 1 control night of undisturbed sleep and 2 experimental nights, during which either SWS or REM sleep was selectively deprived across the entire night (sleep conditions counterbalanced across participants). Polysomnography recordings quantified precisely the amount of SWS and REM sleep that occurred during each of the sleep conditions, and spindle counts were recorded. In the morning, participants completed the experimental tasks in the same sequence as the night before. SWS deprivation disrupted the consolidation of explicit memories for visuospatial information (ηp2 = .23), and both SWS (ηp2 = .53) and REM sleep (ηp2 = .52) deprivation adversely affected explicit verbal recall. Neither SWS nor REM sleep deprivation affected aspects of short-term or working memory, and did not affect measures of verbal implicit memory. Spindle counts did not correlate significantly with memory performance. These findings demonstrate the importance of measuring the sleep cycles throughout the entire night, and the contribution of both SWS and REM sleep to memory consolidation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Pinellia ternata (Thunb.) Makino Preparation promotes sleep by increasing REM sleep.

Science.gov (United States)

Lin, Sisi; Nie, Bo; Yao, Guihong; Yang, Hui; Ye, Ren; Yuan, Zhengzhong

2018-05-15

Pinellia ternata (Thunb.) Makino Preparation (PTP) is widely used to treat insomnia in traditional Chinese medicine; however, its specific role is not clear. In this study, PTP was prepared at three concentrations. For locomotor activity tests, mice were treated with PTP and evaluated for 14 days. For polygraph recordings, mice were treated for 14 days and recorded after treatment. The main chemical constituents in PTP were identified by Ultra performance liquid chromatography/quadrupole time spectrometry (UPLC/Q-TOF-MS). The results showed that 0.9 g/mL PTP significantly reduced locomotor activity. The effect was related to the time of treatment. PTP reduced wakefulness and increased sleep in mice. Furthermore, PTP promoted sleep by increasing the number of REM sleep episodes with a duration of 64-128s and increasing the number of transitions from NREM sleep to REM sleep and from REM sleep to wakefulness. A total of 17 compounds were identified.

A comparative simulation of feed and bleed operation during the total loss of feedwater event by RELAP5/MOD3 and CEFLASH-4AS/REM computer codes

International Nuclear Information System (INIS)

Kwon, Y.M.; Ro, T.S.; Song, J.H.

1995-01-01

The Ulchin 3 and 4 nuclear power plants, which are two-loop 2,825 MW(thermal) pressurized water reactors designed by the Korea Atomic Energy Research Institute, adopted a safety depressurization system (SDS) to mitigate the beyond-design-basis event of a total loss of feedwater (TLOFW). A comparative simulation by the CEFLASH-4AS/REM and RELAP5/MOD3 computer codes for the TLOFW event without operator recovery and the TLOFW event with feed and bleed (F and B) operation is performed for Ulchin 3 and 4. In the analyses, the SDS bleed paths are modeled by orifices located on the top of the pressurizer, where the analytical area of the bleed path is based on the Ulchin 3 and 4 SDS design flow capacity. An additional case, where the SDS piping and valves are modeled explicitly, is considered for the RELAP5 analysis. The predictions by the CEFLASH-4AS/REM of the transient two-phase system behavior show good qualitative and quantitative agreement with those by the RELAP5 simulation. The RELAP5 case with explicit piping results in less repressurization and lower reactor coolant system pressure than that of the case without explicit SDS modeling. However, the two cases of RELAP5 analyses result in essentially the same transient scenarios for TLOFW with F and B operation. The results of the simulation demonstrate the validity of the Ulchin 3 and 4 design approach, which employs CEFLASH-4AS/REM computer code and SDS bleed paths modeled by orifices located on the top of the pressurizer. The results also indicate that the decay heat removal and core inventory makeup function can be successfully accomplished by F and B operation by using the SDS for Ulchin 3 and 4

One step replica symmetry breaking and extreme order statistics of logarithmic REMs

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Xiangyu Cao, Yan V. Fyodorov, Pierre Le Doussal

2016-12-01

Full Text Available Building upon the one-step replica symmetry breaking formalism, duly understood and ramified, we show that the sequence of ordered extreme values of a general class of Euclidean-space logarithmically correlated random energy models (logREMs behave in the thermodynamic limit as a randomly shifted decorated exponential Poisson point process. The distribution of the random shift is determined solely by the large-distance ("infra-red", IR limit of the model, and is equal to the free energy distribution at the critical temperature up to a translation. the decoration process is determined solely by the small-distance ("ultraviolet", UV limit, in terms of the biased minimal process. Our approach provides connections of the replica framework to results in the probability literature and sheds further light on the freezing/duality conjecture which was the source of many previous results for log-REMs. In this way we derive the general and explicit formulae for the joint probability density of depths of the first and second minima (as well its higher-order generalizations in terms of model-specific contributions from UV as well as IR limits. In particular, we show that the second min statistics is largely independent of details of UV data, whose influence is seen only through the mean value of the gap. For a given log-correlated field this parameter can be evaluated numerically, and we provide several numerical tests of our theory using the circular model of $1/f$-noise.

REM Behaviour Disorder Detection Associated with Neurodegerative Diseases

DEFF Research Database (Denmark)

Kempfner, Jacob; Sørensen, Gertrud Laura; Zoetmulder, Marielle

2010-01-01

Abnormal skeleton muscle activity during REM sleep is characterized as REM Behaviour Disorder (RBD), and may be an early marker for different neurodegenerative diseases. Early detection of RBD is therefore highly important, and in this ongoing study a semi-automatic method for RBD detection...... is proposed by analyzing the motor activity during sleep. Method: A total number of twelve patients have been involved in this study, six normal controls and six patients diagnosed with Parkinsons Disease (PD) with RBD. All subjects underwent at least one ambulant polysomnographic (PSG) recording. The sleep...... recordings were scored, according to the new sleep-scoring standard from the American Academy of Sleep Medicine, by two independent sleep specialists. A follow-up analysis of the scoring consensus between the two specialists has been conducted. Based on the agreement of the two manual scorings...

Rev and Rex proteins of human complex retroviruses function with the MMTV Rem-responsive element

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Dudley Jaquelin P

2009-02-01

Full Text Available Abstract Background Mouse mammary tumor virus (MMTV encodes the Rem protein, an HIV Rev-like protein that enhances nuclear export of unspliced viral RNA in rodent cells. We have shown that Rem is expressed from a doubly spliced RNA, typical of complex retroviruses. Several recent reports indicate that MMTV can infect human cells, suggesting that MMTV might interact with human retroviruses, such as human immunodeficiency virus (HIV, human T-cell leukemia virus (HTLV, and human endogenous retrovirus type K (HERV-K. In this report, we test whether the export/regulatory proteins of human complex retroviruses will increase expression from vectors containing the Rem-responsive element (RmRE. Results MMTV Rem, HIV Rev, and HTLV Rex proteins, but not HERV-K Rec, enhanced expression from an MMTV-based reporter plasmid in human T cells, and this activity was dependent on the RmRE. No RmRE-dependent reporter gene expression was detectable using Rev, Rex, or Rec in HC11 mouse mammary cells. Cell fractionation and RNA quantitation experiments suggested that the regulatory proteins did not affect RNA stability or nuclear export in the MMTV reporter system. Rem had no demonstrable activity on export elements from HIV, HTLV, or HERV-K. Similar to the Rem-specific activity in rodent cells, the RmRE-dependent functions of Rem, Rev, or Rex in human cells were inhibited by a dominant-negative truncated nucleoporin that acts in the Crm1 pathway of RNA and protein export. Conclusion These data argue that many retroviral regulatory proteins recognize similar complex RNA structures, which may depend on the presence of cell-type specific proteins. Retroviral protein activity on the RmRE appears to affect a post-export function of the reporter RNA. Our results provide additional evidence that MMTV is a complex retrovirus with the potential for viral interactions in human cells.

Experience-dependent phase-reversal of hippocampal neuron firing during REM sleep.

Science.gov (United States)

Poe, G R; Nitz, D A; McNaughton, B L; Barnes, C A

2000-02-07

The idea that sleep could serve a cognitive function has remained popular since Freud stated that dreams were "not nonsense" but a time to sort out experiences [S. Freud, Letter to Wilhelm Fliess, May 1897, in The Origins of Psychoanalysis - Personal Letters of Sigmund Freud, M. Bonaparte, A. Freud, E. Kris (Eds.), Translated by E. Mosbacher, J. Strachey, Basic Books and Imago Publishing, 1954]. Rapid eye movement (REM) sleep, which is associated with dream reports, is now known to be is important for acquisition of some tasks [A. Karni, D. Tanne, B.S. Rubenstein, J.J.M. Askenasy, D. Sagi, Dependence on REM sleep of overnight improvement of a perceptual skill, Science 265 (1994) 679-682; C. Smith, Sleep states and learning: a review of the animal literature, Biobehav. Rev. 9 (1985) 157-168]; although why this is so remains obscure. It has been proposed that memories may be consolidated during REM sleep or that forgetting of unnecessary material occurs in this state [F. Crick, G. Mitchison, The function of dream sleep, Nature 304 (1983) 111-114; D. Marr, Simple memory: a theory for archicortex, Philos. Trans. R. Soc. B. 262 (1971) 23-81]. We studied the firing of multiple single neurons in the hippocampus, a structure that is important for episodic memory, during familiar and novel experiences and in subsequent REM sleep. Cells active in familiar places during waking exhibited a reversal of firing phase relative to local theta oscillations in REM sleep. Because firing-phase can influence whether synapses are strengthened or weakened [C. Holscher, R. Anwyl, M.J. Rowan, Stimulation on the positive phase of hippocampal theta rhythm induces long-term potentiation that can be depotentiated by stimulation on the negative phase in area CA1 in vivo, J. Neurosci. 15 (1977) 6470-6477; P.T. Huerta, J.E. Lisman, Bidirectional synaptic plasticity induced by a single burst during cholinergic theta oscillation in CA1 in vitro, Neuron 15 (1995) 1053-1063; C. Pavlides, Y

Rapid eye movement (REM sleep deprivation reduces rat frontal cortex acetylcholinesterase (EC 3.1.1.7 activity

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Camarini R.

1997-01-01

Full Text Available Rapid eye movement (REM sleep deprivation induces several behavioral changes. Among these, a decrease in yawning behavior produced by low doses of cholinergic agonists is observed which indicates a change in brain cholinergic neurotransmission after REM sleep deprivation. Acetylcholinesterase (Achase controls acetylcholine (Ach availability in the synaptic cleft. Therefore, altered Achase activity may lead to a change in Ach availability at the receptor level which, in turn, may result in modification of cholinergic neurotransmission. To determine if REM sleep deprivation would change the activity of Achase, male Wistar rats, 3 months old, weighing 250-300 g, were deprived of REM sleep for 96 h by the flower-pot technique (N = 12. Two additional groups, a home-cage control (N = 6 and a large platform control (N = 6, were also used. Achase was measured in the frontal cortex using two different methods to obtain the enzyme activity. One method consisted of the obtention of total (900 g supernatant, membrane-bound (100,000 g pellet and soluble (100,000 g supernatant Achase, and the other method consisted of the obtention of a fraction (40,000 g pellet enriched in synaptic membrane-bound enzyme. In both preparations, REM sleep deprivation induced a significant decrease in rat frontal cortex Achase activity when compared to both home-cage and large platform controls. REM sleep deprivation induced a significant decrease of 16% in the membrane-bound Achase activity (nmol thiocholine formed min-1 mg protein-1 in the 100,000 g pellet enzyme preparation (home-cage group 152.1 ± 5.7, large platform group 152.7 ± 24.9 and REM sleep-deprived group 127.9 ± 13.8. There was no difference in the soluble enzyme activity. REM sleep deprivation also induced a significant decrease of 20% in the enriched synaptic membrane-bound Achase activity (home-cage group 126.4 ± 21.5, large platform group 127.8 ± 20.4, REM sleep-deprived group 102.8 ± 14.2. Our results

Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training

Science.gov (United States)

Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

2011-01-01

This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was divided into the initial spatial learning phase (3.5 d) immediately followed by the reversal phase (2.5 d). During the 6 h following four or 12 training trials/day of initial or reversal learning phases, REM sleep was eliminated and non-REM sleep left intact using the multiple inverted flowerpot method. Contrary to our hypotheses, REM sleep deprivation during four or 12 trials/day of initial spatial or reversal learning did not affect training performance. However, some probe trial measures indicated REM sleep-deprivation–associated impairment in initial spatial learning with four trials/day and enhancement of subsequent reversal learning. In naive animals, REM sleep deprivation during normal initial spatial learning was followed by a lack of preference for the subsequent reversal platform location during the probe. Our findings contradict reports that REM sleep is essential for spatial learning in the Morris water maze and newly reveal that short periods of REM sleep deprivation do not impair concurrent reversal learning. Effects on subsequent reversal learning are consistent with the idea that REM sleep serves the consolidation of incompletely learned items. PMID:21677190

El trastorno de conducta del sueño rem

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Alex Iranzo De Riquer, Dr.

2013-05-01

Full Text Available El trastorno de conducta durante el sueño REM (TCSR se caracteriza por conductas motoras vigorosas, pesadillas y ausencia de atonía muscular durante el sueño REM. Se debe a la disfunción directa o indirecta de las estructuras del tronco cerebral que regulan el sueño REM, especialmente el núcleo subceruleus. El TCSR puede ser idiopático o asociado a enfermedades neurológicas como la enfermedad de Parkinson (EP, la demencia con cuerpos de Lewy (DCL, la atrofia multisistémica (AMS y la narcolepsia. Los pacientes con la forma idiopática, especialmente los que tienen alterados el SPECT del transportador de la dopamina, la sonografía de la sustancia negra, los test de olfato y de la visión de colores, tienen un elevado riesgo de desarrollar la E P, DCL y AMS. El TCSR no debe considerarse como un simple trastorno del sueño, sino como una manifestación de una enfermedad neurológica. El clonazepam (0.25-4 mg y la melatonina (3-12 mg a la hora de acostarse mejoran los síntomas del TCSR pero no evitan, en la forma idiopática, la conversión a una enfermedad neurodegenerativa.

Differential modulation of global and local neural oscillations in REM sleep by homeostatic sleep regulation.

Science.gov (United States)

Kim, Bowon; Kocsis, Bernat; Hwang, Eunjin; Kim, Youngsoo; Strecker, Robert E; McCarley, Robert W; Choi, Jee Hyun

2017-02-28

Homeostatic rebound in rapid eye movement (REM) sleep normally occurs after acute sleep deprivation, but REM sleep rebound settles on a persistently elevated level despite continued accumulation of REM sleep debt during chronic sleep restriction (CSR). Using high-density EEG in mice, we studied how this pattern of global regulation is implemented in cortical regions with different functions and network architectures. We found that across all areas, slow oscillations repeated the behavioral pattern of persistent enhancement during CSR, whereas high-frequency oscillations showed progressive increases. This pattern followed a common rule despite marked topographic differences. The findings suggest that REM sleep slow oscillations may translate top-down homeostatic control to widely separated brain regions whereas fast oscillations synchronizing local neuronal ensembles escape this global command. These patterns of EEG oscillation changes are interpreted to reconcile two prevailing theories of the function of sleep, synaptic homeostasis and sleep dependent memory consolidation.

The role of REM sleep in the processing of emotional memories: evidence from behavior and event-related potentials.

Science.gov (United States)

Groch, S; Wilhelm, I; Diekelmann, S; Born, J

2013-01-01

Emotional memories are vividly remembered for the long-term. Rapid eye movement (REM) sleep has been repeatedly proposed to support the superior retention of emotional memories. However, its exact contribution and, specifically, whether its effect is mainly on the consolidation of the contents or the processing of the affective component of emotional memories is not clear. Here, we investigated the effects of sleep rich in slow wave sleep (SWS) or REM sleep on the consolidation of emotional pictures and the accompanying changes in affective tone, using event-related potentials (ERPs) together with subjective ratings of valence and arousal. Sixteen healthy, young men learned 50 negative and 50 neutral pictures before 3-h retention sleep intervals that were filled with either SWS-rich early or REM sleep-rich late nocturnal sleep. In accordance with our hypothesis, recognition was better for emotional pictures than neutral pictures after REM compared to SWS-rich sleep. This emotional enhancement after REM-rich sleep expressed itself in an increased late positive potential of the ERP over the frontal cortex 300-500 ms after stimulus onset for correctly classified old emotional pictures compared with new emotional and neutral pictures. Valence and arousal ratings of emotional pictures were not differentially affected by REM or SWS-rich sleep after learning. Our results corroborate that REM sleep contributes to the consolidation of emotional contents in memory, but suggest that the affective tone is preserved rather than reduced by the processing of emotional memories during REM sleep. Copyright © 2012 Elsevier Inc. All rights reserved.

Effects of chronic REM sleep restriction on D1 receptor and related signal pathways in rat prefrontal cortex.

Science.gov (United States)

Han, Yan; Wen, Xiaosa; Rong, Fei; Chen, Xinmin; Ouyang, Ruying; Wu, Shuai; Nian, Hua; Ma, Wenling

2015-01-01

The prefrontal cortex (PFC) mediates cognitive function that is sensitive to disruption by sleep loss, and molecular mechanisms regulating neural dysfunction induced by chronic sleep restriction (CSR), particularly in the PFC, have yet to be completely understood. The aim of the present study was to investigate the effect of chronic REM sleep restriction (REM-CSR) on the D1 receptor (D1R) and key molecules in D1R' signal pathways in PFC. We employed the modified multiple platform method to create the REM-CSR rat model. The ultrastructure of PFC was observed by electron microscopy. HPLC was performed to measure the DA level in PFC. The expressions of genes and proteins of related molecules were assayed by real-time PCR and Western blot, respectively. The general state and morphology of PFC in rats were changed by CSR, and DA level and the expression of D1R in PFC were markedly decreased (P CSR rats (P CSR induced cognitive dysfunction, and the PKA pathway of D1R may play an important role in the impairment of advanced neural function.

The monetary value of the collective dose equivalent unit (person-rem)

International Nuclear Information System (INIS)

Rodgers, Reginald C.

1978-01-01

In the design and operation of nuclear power reactor facilities, it is recommended that radiation exposures to the workers and the general public be kept as 'low as reasonably achievable' (ALARA). In the process of implementing this principle cost-benefit evaluations are part of the decision making process. For this reason a monetary value has to be assigned to the collective dose equivalent unit (person-rem). The various factors such as medical health care, societal penalty and manpower replacement/saving are essential ingredients to determine a monetary value for the person-rem. These factors and their dependence on the level of risk (or exposure level) are evaluated. Monetary values of well under $100 are determined for the public dose equivalent unit. The occupational worker person-rem value is determined to be in the range of $500 to about $5000 depending on the exposure level and the type of worker and his affiliation, i.e., temporary or permanent. A discussion of the variability and the range of the monetary values will be presented. (author)

Observations on muscle activity in REM sleep behavior disorder assessed with a semi-automated scoring algorithm

DEFF Research Database (Denmark)

Jeppesen, Jesper; Otto, Marit; Frederiksen, Yoon

2018-01-01

OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is defined by dream enactment due to a failure of normal muscle atonia. Visual assessment of this muscle activity is time consuming and rater-dependent. METHODS: An EMG computer algorithm for scoring 'tonic', 'phasic' and 'any......' submental muscle activity during REM sleep was evaluated compared with human visual ratings. Subsequently, 52 subjects were analyzed with the algorithm. Duration and maximal amplitude of muscle activity, and self-awareness of RBD symptoms were assessed. RESULTS: The computer algorithm showed high congruency...... sleep without atonia. CONCLUSIONS: Our proposed algorithm was able to detect and rate REM sleep without atonia allowing identification of RBD. Increased duration and amplitude of muscle activity bouts were characteristics of RBD. Quantification of REM sleep without atonia represents a marker of RBD...

Sleep electroencephalography as a biomarker in depression

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Steiger A

2015-04-01

Full Text Available Axel Steiger, Marcel Pawlowski, Mayumi Kimura Max Planck Institute of Psychiatry, Munich, Germany Abstract: The sleep electroencephalogram (EEG provides biomarkers of depression, which may help with diagnosis, prediction of therapy response, and prognosis in the treatment of depression. In patients with depression, characteristic sleep EEG changes include impaired sleep continuity, disinhibition of rapid-eye-movement (REM sleep, and impaired non-REM sleep. Most antidepressants suppress REM sleep in depressed patients, healthy volunteers, and in animal models. REM suppression appears to be an important, but not an absolute requirement, for antidepressive effects of a substance. Enhanced REM density, a measure for frequency of REM, characterizes high-risk probands for affective disorders. REM-sleep changes were also found in animal models of depression. Sleep-EEG variables were shown to predict the response to treatment with antidepressants. Furthermore, certain clusters of sleep EEG variables predicted the course of the disorder for several years. Some of the predicted sleep EEG markers appear to be related to hypothalamic–pituitary–adrenal system activity. Keywords: biomarkers, depression, sleep EEG, antidepressants, prediction, animal models

REM-sleep alterations in children with co-existence of tic disorders and attention-deficit/hyperactivity disorder: impact of hypermotor symptoms.

Science.gov (United States)

Kirov, Roumen; Banaschewski, Tobias; Uebel, Henrik; Kinkelbur, Jörg; Rothenberger, Aribert

2007-06-01

To characterize precisely the sleep pattern in children with co-existence of TD + ADHD. By means of polysomnography, sleep pattern was investigated in 19 children with TD + ADHD unmedicated before and during study and 19 healthy controls, matched for age, gender, and intelligence. Compared with healthy controls, children with TD + ADHD displayed shorter REM sleep latency and increased REM sleep duration. There was a negative correlational relationship between these REM-sleep alterations and they were determined by hyperactivity symptoms. Sleep in children with coexistence of TD + ADHD may be characterized by an elevated REM sleep drive. Common mechanisms are suggested to underpin hypermotor symptoms and REM sleep regulation.

Locus Coeruleus and Tuberomammillary Nuclei Ablations Attenuate Hypocretin/Orexin Antagonist-Mediated REM Sleep.

Science.gov (United States)

Schwartz, Michael D; Nguyen, Alexander T; Warrier, Deepti R; Palmerston, Jeremiah B; Thomas, Alexia M; Morairty, Stephen R; Neylan, Thomas C; Kilduff, Thomas S

2016-01-01

Hypocretin 1 and 2 (Hcrts; also known as orexin A and B), excitatory neuropeptides synthesized in cells located in the tuberal hypothalamus, play a central role in the control of arousal. Hcrt inputs to the locus coeruleus norepinephrine (LC NE) system and the posterior hypothalamic histaminergic tuberomammillary nuclei (TMN HA) are important efferent pathways for Hcrt-induced wakefulness. The LC expresses Hcrt receptor 1 (HcrtR1), whereas HcrtR2 is found in the TMN. Although the dual Hcrt/orexin receptor antagonist almorexant (ALM) decreases wakefulness and increases NREM and REM sleep time, the neural circuitry that mediates these effects is currently unknown. To test the hypothesis that ALM induces sleep by selectively disfacilitating subcortical wake-promoting populations, we ablated LC NE neurons (LCx) or TMN HA neurons (TMNx) in rats using cell-type-specific saporin conjugates and evaluated sleep/wake following treatment with ALM and the GABAA receptor modulator zolpidem (ZOL). Both LCx and TMNx attenuated the promotion of REM sleep by ALM without affecting ALM-mediated increases in NREM sleep. Thus, eliminating either HcrtR1 signaling in the LC or HcrtR2 signaling in the TMN yields similar effects on ALM-induced REM sleep without affecting NREM sleep time. In contrast, neither lesion altered ZOL efficacy on any measure of sleep-wake regulation. These results contrast with those of a previous study in which ablation of basal forebrain cholinergic neurons attenuated ALM-induced increases in NREM sleep time without affecting REM sleep, indicating that Hcrt neurotransmission influences distinct aspects of NREM and REM sleep at different locations in the sleep-wake regulatory network.

From the skyscraper to the ground-scraper. Rem Koolhaas’s Japanese Kasbah

OpenAIRE

Álvarez Arce, Raquel

2016-01-01

Rem Koolhaas, as a contemporary architect, draws from the proposals which were devel-oped by the architects who reacted to the ideas formulated on the International Congresses of Modern Architecture, like the Team 10 members. Woods, along with Candilis and Josic, worked out a new type of building that he called ground-scrapper, although it is better known by the name given by Alison Smithson: the mat-building. Rem Koolhaas, in the Nexus World building in Fukuoka, propose, as he says in S,M,L,...

Calculations of dosimetric parameter and REM meter response for BE(d, n) source

International Nuclear Information System (INIS)

Chen Changmao

1988-01-01

Based on the recent data about neutron spectra, the average energy, effictive energy and conversion coefficient of fluence to dose equivalent are calculated for some Be (α, n) neutron sources which have differene types and structures. The responses of 2202D and 0075 REM meter for thses spectral neutrons are also estimated. The results indicate that the relationship between average energy and conversion coefficient or REM meter responses can be described by simple functions

Log-correlated random-energy models with extensive free-energy fluctuations: Pathologies caused by rare events as signatures of phase transitions

Science.gov (United States)

Cao, Xiangyu; Fyodorov, Yan V.; Le Doussal, Pierre

2018-02-01

We address systematically an apparent nonphysical behavior of the free-energy moment generating function for several instances of the logarithmically correlated models: the fractional Brownian motion with Hurst index H =0 (fBm0) (and its bridge version), a one-dimensional model appearing in decaying Burgers turbulence with log-correlated initial conditions and, finally, the two-dimensional log-correlated random-energy model (logREM) introduced in Cao et al. [Phys. Rev. Lett. 118, 090601 (2017), 10.1103/PhysRevLett.118.090601] based on the two-dimensional Gaussian free field with background charges and directly related to the Liouville field theory. All these models share anomalously large fluctuations of the associated free energy, with a variance proportional to the log of the system size. We argue that a seemingly nonphysical vanishing of the moment generating function for some values of parameters is related to the termination point transition (i.e., prefreezing). We study the associated universal log corrections in the frozen phase, both for logREMs and for the standard REM, filling a gap in the literature. For the above mentioned integrable instances of logREMs, we predict the nontrivial free-energy cumulants describing non-Gaussian fluctuations on the top of the Gaussian with extensive variance. Some of the predictions are tested numerically.

Increased Ventricular Premature Contraction Frequency During REM Sleep in Patients with Coronary Artery Disease and Obstructive Sleep Apnea

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Mari A. Watanabe

2008-11-01

Full Text Available Background Patients with obstructive sleep apnea are reported to have a peak of sudden cardiac death at night, in contrast to patients without apnea whose peak is in the morning. We hypothesized that ventricular premature contraction (VPC frequency would correlate with measures of apnea and sympathetic activity.Methods Electrocardiograms from a sleep study of 125 patients with coronary artery disease were evaluated. Patients were categorized by apnea-hypopnea index (AHI into Moderate (AHI 15 apnea groups. Sleep stages studied were Wake, S1, S2, S34, and rapid eye movement (REM. Parameters of a potent autonomically-based risk predictor for sudden cardiac death called heart rate turbulence were calculated.Results There were 74 Moderate and 51 Severe obstructive sleep apnea patients. VPC frequency was affected significantly by sleep stage (Wake, S2 and REM, F=5.8, p<.005 and by AHI (F=8.7, p<.005. In Severe apnea patients, VPC frequency was higher in REM than in Wake (p=.011. In contrast, patients with Moderate apnea had fewer VPCs and exhibited no sleep stage dependence (p=.19. Oxygen desaturation duration per apnea episode correlated positively with AHI (r2=.71, p<.0001, and was longer in REM than in non-REM (p<.0001. The heart rate turbulence parameter TS correlated negatively with oxygen desaturation duration in REM (r2=.06, p=.014.Conclusions Higher VPC frequency coupled with higher sympathetic activity caused by longer apnea episodes in REM sleep may be one reason for increased nocturnal death in apneic patients.

Changes in EEG power density of non-REM sleep in depressed patients during treatment with trazodone

NARCIS (Netherlands)

Bemmel, Alex L. van; Beersma, Domien G.M.; Hoofdakker, Rutger H. van den

1995-01-01

Recently, it was hypothesized that acute or cumulative suppression of non-REM sleep intensity might be related to the therapeutic effects of antidepressants. This intensity has been proposed to be expressed in the EEG power density in non-REM sleep. In the present study, the relationship was

Rapid expansion method (REM) for time‐stepping in reverse time migration (RTM)

KAUST Repository

Pestana, Reynam C.

2009-01-01

We show that the wave equation solution using a conventional finite‐difference scheme, derived commonly by the Taylor series approach, can be derived directly from the rapid expansion method (REM). After some mathematical manipulation we consider an analytical approximation for the Bessel function where we assume that the time step is sufficiently small. From this derivation we find that if we consider only the first two Chebyshev polynomials terms in the rapid expansion method we can obtain the second order time finite‐difference scheme that is frequently used in more conventional finite‐difference implementations. We then show that if we use more terms from the REM we can obtain a more accurate time integration of the wave field. Consequently, we have demonstrated that the REM is more accurate than the usual finite‐difference schemes and it provides a wave equation solution which allows us to march in large time steps without numerical dispersion and is numerically stable. We illustrate the method with post and pre stack migration results.

Sleepiness in Idiopathic REM Sleep Behavior Disorder and Parkinson Disease.

Science.gov (United States)

Arnulf, Isabelle; Neutel, Dulce; Herlin, Bastien; Golmard, Jean-Louis; Leu-Semenescu, Smaranda; Cochen de Cock, Valérie; Vidailhet, Marie

2015-10-01

To determine whether patients with idiopathic and symptomatic RBD were sleepier than controls, and if sleepiness in idiopathic RBD predicted earlier conversion to Parkinson disease. The Epworth Sleepiness Scale (ESS) and its determinants were compared at the time of a video-polysomnography for an RBD diagnosis in patients with idiopathic RBD, in patients with Parkinson disease, and in controls. Whether sleepiness at time of RBD diagnosis predicted an earlier conversion to neurodegenerative diseases was retrospectively analyzed in the followed-up patients. The 75 patients with idiopathic RBD were sleepier (ESS: 7.8 ± 4.6) at the time of RBD diagnosis than 74 age- and sex-matched controls (ESS: 5.0 ± 3.6, P sleep measures. Among the 69 patients with idiopathic RBD who were followed up for a median 3 years (1-15 years), 16 (23.2%) developed parkinsonism (n = 6), dementia (n = 6), dementia plus parkinsonism (n = 2), and multiple system atrophy (n = 2). An ESS greater than 8 at time of RBD diagnosis predicted a shorter time to phenoconversion to parkinsonism and dementia, from RBD onset, and from RBD diagnosis (when adjusted for age and time between RBD onset and diagnosis). Sleepiness is associated with idiopathic REM sleep behavior disorder and predicts more rapid conversion to parkinsonism and dementia, suggesting it is an early marker of neuronal loss in brainstem arousal systems. © 2015 Associated Professional Sleep Societies, LLC.

Relabeling exchange method (REM) for learning in neural networks

Science.gov (United States)

Wu, Wen; Mammone, Richard J.

1994-02-01

The supervised training of neural networks require the use of output labels which are usually arbitrarily assigned. In this paper it is shown that there is a significant difference in the rms error of learning when `optimal' label assignment schemes are used. We have investigated two efficient random search algorithms to solve the relabeling problem: the simulated annealing and the genetic algorithm. However, we found them to be computationally expensive. Therefore we shall introduce a new heuristic algorithm called the Relabeling Exchange Method (REM) which is computationally more attractive and produces optimal performance. REM has been used to organize the optimal structure for multi-layered perceptrons and neural tree networks. The method is a general one and can be implemented as a modification to standard training algorithms. The motivation of the new relabeling strategy is based on the present interpretation of dyslexia as an encoding problem.

Hallucinations and REM sleep behaviour disorder in Parkinson's disease: dream imagery intrusions and other hypotheses.

Science.gov (United States)

Manni, Raffaele; Terzaghi, Michele; Ratti, Pietro-Luca; Repetto, Alessandra; Zangaglia, Roberta; Pacchetti, Claudio

2011-12-01

REM sleep behaviour disorder (RBD) is a REM sleep-related parasomnia which may be considered a "dissociated state of wakefulness and sleep", given that conflicting elements of REM sleep (dreaming) and of wakefulness (sustained muscle tone and movements) coexist during the episodes, leading to motor and behavioural manifestations reminiscent of an enacted dream. RBD has been reported in association with α-synucleinopathies: around a third of patients with Parkinson's disease (PD) have full-blown RBD. Recent data indicate that PD patients with RBD are more prone to hallucinations than PD patients without this parasomnia. However it is still not clear why RBD in PD is associated with an increased prevalence of VHs. Data exist which suggest that visual hallucinations in PD may be the result of untimely intrusions of REM visual imagery into wakefulness. RBD, which is characterised by a REM sleep dissociation pattern, might be a condition that particularly favours such intrusions. However, other hypotheses may be advanced. In fact, deficits in attentional, executive, visuoperceptual and visuospatial abilities have been documented in RBD and found to occur far more frequently in PD with RBD than in PD without RBD. Neuropsychological deficits involving visual perception and attentional processes are thought to play an important role in the pathophysiology of VHs. On this basis, RBD in PD could be viewed as a contributory risk factor for VHs. Copyright © 2010 Elsevier Inc. All rights reserved.

Visual short-term memory deficits in REM sleep behaviour disorder mirror those in Parkinson's disease.

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Rolinski, Michal; Zokaei, Nahid; Baig, Fahd; Giehl, Kathrin; Quinnell, Timothy; Zaiwalla, Zenobia; Mackay, Clare E; Husain, Masud; Hu, Michele T M

2016-01-01

Individuals with REM sleep behaviour disorder are at significantly higher risk of developing Parkinson's disease. Here we examined visual short-term memory deficits--long associated with Parkinson's disease--in patients with REM sleep behaviour disorder without Parkinson's disease using a novel task that measures recall precision. Visual short-term memory for sequentially presented coloured bars of different orientation was assessed in 21 patients with polysomnography-proven idiopathic REM sleep behaviour disorder, 26 cases with early Parkinson's disease and 26 healthy controls. Three tasks using the same stimuli controlled for attentional filtering ability, sensorimotor and temporal decay factors. Both patients with REM sleep behaviour disorder and Parkinson's disease demonstrated a deficit in visual short-term memory, with recall precision significantly worse than in healthy controls with no deficit observed in any of the control tasks. Importantly, the pattern of memory deficit in both patient groups was specifically explained by an increase in random responses. These results demonstrate that it is possible to detect the signature of memory impairment associated with Parkinson's disease in individuals with REM sleep behaviour disorder, a condition associated with a high risk of developing Parkinson's disease. The pattern of visual short-term memory deficit potentially provides a cognitive marker of 'prodromal' Parkinson's disease that might be useful in tracking disease progression and for disease-modifying intervention trials. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

Materials properties, loads, and stress analysis, Spartan REM: Appendix A

Science.gov (United States)

Marlowe, D. S.; West, E. J.

1984-01-01

The mechanical properties, load tests, and stress analysis of the Spartan Release Engagement Mechanism (REM) is presented. The fracture properties of the components of the unit are also discussed. Detailed engineering drawings are included.

A probability score for preoperative prediction of type 2 diabetes remission following RYGB surgery

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Still, Christopher D.; Wood, G. Craig; Benotti, Peter; Petrick, Anthony T.; Gabrielsen, Jon; Strodel, William E.; Ibele, Anna; Seiler, Jamie; Irving, Brian A.; Celaya, Melisa P.; Blackstone, Robin; Gerhard, Glenn S.; Argyropoulos, George

2014-01-01

BACKGROUND Type 2 diabetes (T2D) is a metabolic disease with significant medical complications. Roux-en-Y gastric bypass (RYGB) surgery is one of the few interventions that remit T2D in ~60% of patients. However, there is no accurate method for predicting preoperatively the probability for T2D remission. METHODS A retrospective cohort of 2,300 RYGB patients at Geisinger Clinic was used to identify 690 patients with T2D and complete electronic data. Two additional T2D cohorts (N=276, and N=113) were used for replication at 14 months following RYGB. Kaplan-Meier analysis was used in the primary cohort to create survival curves until remission. A Cox proportional hazards model was used to estimate the hazard ratios on T2D remission. FINDINGS Using 259 preoperative clinical variables, four (use of insulin, age, HbA1c, and type of antidiabetic medication) were sufficient to develop an algorithm that produces a type 2 diabetes remission (DiaRem) score over five years. The DiaRem score spans from 0 to 22 and was divided into five groups corresponding to five probability-ranges for T2D remission: 0–2 (88%–99%), 3–7 (64%–88%), 8–12 (23%–49%), 13–17 (11%–33%), 18–22 (2%–16%). The DiaRem scores in the replication cohorts, as well as under various definitions of diabetes remission, conformed to the DiaRem score of the primary cohort. INTERPRETATION The DiaRem score is a novel preoperative method for predicting the probability (from 2% to 99%) for T2D remission following RYGB surgery. FUNDING This research was supported by the Geisinger Health System and the National Institutes of Health. PMID:24579062

Replay of conditioned stimuli during late REM and stage N2 sleep influences affective tone rather than emotional memory strength.

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Rihm, Julia S; Rasch, Björn

2015-07-01

Emotional memories are reprocessed during sleep, and it is widely assumed that this reprocessing occurs mainly during rapid eye movement (REM) sleep. In support for this notion, vivid emotional dreams occur mainly during REM sleep, and several studies have reported emotional memory enhancement to be associated with REM sleep or REM sleep-related parameters. However, it is still unknown whether reactivation of emotional memories during REM sleep strengthens emotional memories. Here, we tested whether re-presentation of emotionally learned stimuli during REM sleep enhances emotional memory. In a split-night design, participants underwent Pavlovian conditioning after the first half of the night. Neutral sounds served as conditioned stimuli (CS) and were either paired with a negative odor (CS+) or an odorless vehicle (CS-). During sound replay in subsequent late REM or N2 sleep, half of the CS+ and half of the CS- were presented again. In contrast to our hypothesis, replay during sleep did not affect emotional memory as measured by the differentiation between CS+ and CS- in expectancy, arousal and valence ratings. However, replay unspecifically decreased subjective arousal ratings of both emotional and neutral sounds and increased positive valence ratings also for both CS+ and CS- sounds, respectively. These effects were slightly more pronounced for replay during REM sleep. Our results suggest that re-exposure to previously conditioned stimuli during late sleep does not affect emotional memory strength, but rather influences the affective tone of both emotional and neutral memories. Copyright © 2015 Elsevier Inc. All rights reserved.

REM sleep behavior disorder in Parkinson′s disease: A case from India confirmed with polysomnographic data

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Ravi Gupta

2013-01-01

Full Text Available Rapid eye movement (REM sleep behavior disorder is a condition characterized by dream enactment. This condition may accompany neurodegenerative disorders. However, only a few reports from India are available, that too, without any polysomnographic evidence. We are reporting a case of REM sleep behavior disorder with polysomnographic evidence.

In vitro model for the study of the role of the mesopontine region in rapid eye movement (REM sleep and wakefulness.

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Esteban Pino

2017-06-01

Full Text Available O estudo de estratégias neurais para a organização do comportamento em vertebrados constitui um desafio maior para a neurociencia. O avanço do conhecimento nessa área depende criticamente da utilização de modelos experimentais adequados que suportem múltiplos níveis de análise (por exemplo: comportamental, circuital, celular,  sináptico e molecular e abordagens por múltiplas técnicas. Decidiu-se analisar in vitro uma rede neural da união mesopontina do tronco encefálico criticamente envolvida no controle do sono de movimentos oculares rápidos (S-REM. Apesar da riqueza de provas que sustentam o papel desta rede em relação ao S-REM, os mecanismos celulares e sinápticos subjacentes a este controle são pouco conhecidos e permanecem sob intensa investigação. Para avançar no conhecimento desses mecanismos, caracterizou-se morfológica e funcionalmente uma fatia de tronco encefálico de rato, na qual as estruturas críticas para o controle do S-REM, i.e.: núcleos tegmentais laterodorsal e pedunculopontino, e sua projeção para o núcleo reticular pontis oralis (PnO estão presentes e operantes. A inclusão do núcleo motor do trigêmeo na fatia permitiu detectar mudanças da excitabilidade das motoneuronas provocadas por manipulações farmacológicas do PnO, representativas das alterações do tônus muscular associados com operações semelhantes quando realizados in vivo. A utlização deste modelo in vitro de S-REM permitirá contribuir para a elucidação de estratégias neurais que operam em níveis intermedios de organização do SN de mamíferos para a geração e regulação de um estado comportamental.

Why does serotonergic activity drastically decrease during REM sleep?

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Sato, Kohji

2013-10-01

Here, I postulate two hypotheses that can explain the missing link between sleep and the serotonergic system in terms of spine homeostasis and memory consolidation. As dendritic spines contain many kinds of serotonin receptors, and the activation of serotonin receptors generally increases the number of spines in the cortex and hippocampus, I postulate that serotonin neurons are down-regulated during sleep to decrease spine number, which consequently maintains the total spine number at a constant level. Furthermore, since synaptic consolidation during REM sleep needs long-term potentiation (LTP), and serotonin is reported to inhibit LTP in the cortex, I postulate that serotonergic activity must drastically decrease during REM sleep to induce LTP and do memory consolidation. Until now, why serotonergic neurons show these dramatic changes in the sleep-wake cycle remains unexplained; however, making these hypotheses, I can confer physiological meanings on these dramatic changes of serotonergic neurons in terms of spine homeostasis and memory consolidation. Copyright © 2013. Published by Elsevier Ltd.

A Direct Test of the Differentiation Mechanism: REM, BCDMEM, and the Strength-Based Mirror Effect in Recognition Memory

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Starns, Jeffrey J.; White, Corey N.; Ratcliff, Roger

2010-01-01

We explore competing explanations for the reduction in false alarm rate observed when studied items are strengthened. Some models, such as Retrieving Effectively from Memory (REM; Shiffrin & Steyvers, 1997), attribute the false alarm rate reduction to differentiation, a process in which strengthening memory traces at study directly reduces the…

A remorin gene SiREM6, the target gene of SiARDP, from foxtail millet (Setaria italica) promotes high salt tolerance in transgenic Arabidopsis.

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Yue, Jing; Li, Cong; Liu, Yuwei; Yu, Jingjuan

2014-01-01

Remorin proteins (REMs) form a plant-specific protein family, with some REMs being responsive to abiotic stress. However, the precise functions of REMs in abiotic stress tolerance are not clear. In this study, we identified 11 remorin genes from foxtail millet (Setaria italica) and cloned a remorin gene, SiREM6, for further investigation. The transcript level of SiREM6 was increased by high salt stress, low temperature stress and abscisic acid (ABA) treatment, but not by drought stress. The potential oligomerization of SiREM6 was examined by negative staining electron microscopy. The overexpression of SiREM6 improved high salt stress tolerance in transgenic Arabidopsis at the germination and seedling stages as revealed by germination rate, survival rate, relative electrolyte leakage and proline content. The SiREM6 promoter contains two dehydration responsive elements (DRE) and one ABA responsive element (ABRE). An ABA responsive DRE-binding transcription factor, SiARDP, and an ABRE-binding transcription factor, SiAREB1, were cloned from foxtail millet. SiARDP could physically bind to the DREs, but SiAREB1 could not. These results revealed that SiREM6 is a target gene of SiARDP and plays a critical role in high salt stress tolerance.

A remorin gene SiREM6, the target gene of SiARDP, from foxtail millet (Setaria italica promotes high salt tolerance in transgenic Arabidopsis.

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Jing Yue

Full Text Available Remorin proteins (REMs form a plant-specific protein family, with some REMs being responsive to abiotic stress. However, the precise functions of REMs in abiotic stress tolerance are not clear. In this study, we identified 11 remorin genes from foxtail millet (Setaria italica and cloned a remorin gene, SiREM6, for further investigation. The transcript level of SiREM6 was increased by high salt stress, low temperature stress and abscisic acid (ABA treatment, but not by drought stress. The potential oligomerization of SiREM6 was examined by negative staining electron microscopy. The overexpression of SiREM6 improved high salt stress tolerance in transgenic Arabidopsis at the germination and seedling stages as revealed by germination rate, survival rate, relative electrolyte leakage and proline content. The SiREM6 promoter contains two dehydration responsive elements (DRE and one ABA responsive element (ABRE. An ABA responsive DRE-binding transcription factor, SiARDP, and an ABRE-binding transcription factor, SiAREB1, were cloned from foxtail millet. SiARDP could physically bind to the DREs, but SiAREB1 could not. These results revealed that SiREM6 is a target gene of SiARDP and plays a critical role in high salt stress tolerance.

A new view of “dream enactment” in REM sleep behavior disorder

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Blumberg, Mark S.; Plumeau, Alan M.

2015-01-01

SUMMARY REM sleep behavior disorder (RBD) is a disorder in which patients exhibit increased muscle tone and exaggerated myoclonic twitching during REM sleep. In addition, violent movements of the limbs, and complex behaviors that can sometimes appear to involve the enactment of dreams, are associated with RBD. These behaviors are widely thought to result from a dysfunction involving atonia-producing neural circuitry in the brainstem, thereby unmasking cortically generated dreams. Here we scrutinize the assumptions that led to this interpretation of RBD. In particular, we challenge the assumption that motor cortex produces twitches during REM sleep, thus calling into question the related assumption that motor cortex is primarily responsible for all of the pathological movements of RBD. Moreover, motor cortex is not even necessary to produce complex behavior; for example, stimulation of some brainstem structures can produce defensive and aggressive behaviors in rats and monkeys that are striking similar to those reported in human patients with RBD. Accordingly, we suggest an interpretation of RBD that focuses increased attention on the brainstem as a source of the pathological movements and that considers sensory feedback from moving limbs as an important influence on the content of dream mentation. PMID:26802823

Hypothalamic L-Histidine Decarboxylase Is Up-Regulated During Chronic REM Sleep Deprivation of Rats.

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Gloria E Hoffman

Full Text Available A competition of neurobehavioral drives of sleep and wakefulness occurs during sleep deprivation. When enforced chronically, subjects must remain awake. This study examines histaminergic neurons of the tuberomammillary nucleus of the posterior hypothalamus in response to enforced wakefulness in rats. We tested the hypothesis that the rate-limiting enzyme for histamine biosynthesis, L-histidine decarboxylase (HDC, would be up-regulated during chronic rapid eye movement sleep deprivation (REM-SD because histamine plays a major role in maintaining wakefulness. Archived brain tissues of male Sprague Dawley rats from a previous study were used. Rats had been subjected to REM-SD by the flowerpot paradigm for 5, 10, or 15 days. For immunocytochemistry, rats were transcardially perfused with acrolein-paraformaldehyde for immunodetection of L-HDC; separate controls used carbodiimide-paraformaldehyde for immunodetection of histamine. Immunolocalization of histamine within the tuberomammillary nucleus was validated using carbodiimide. Because HDC antiserum has cross-reactivity with other decarboxylases at high antibody concentrations, titrations localized L-HDC to only tuberomammillary nucleus at a dilution of ≥ 1:300,000. REM-SD increased immunoreactive HDC by day 5 and it remained elevated in both dorsal and ventral aspects of the tuberomammillary complex. Our results suggest that up-regulation of L-HDC within the tuberomammillary complex during chronic REM-SD may be responsible for maintaining wakefulness.

Spatial and Reversal Learning in the Morris Water Maze Are Largely Resistant to Six Hours of REM Sleep Deprivation Following Training

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Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

2011-01-01

This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair…

Rem uncouples excitation–contraction coupling in adult skeletal muscle fibers

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Beqollari, Donald; Romberg, Christin F.; Filipova, Dilyana; Meza, Ulises; Papadopoulos, Symeon

2015-01-01

In skeletal muscle, excitation–contraction (EC) coupling requires depolarization-induced conformational rearrangements in L-type Ca2+ channel (CaV1.1) to be communicated to the type 1 ryanodine-sensitive Ca2+ release channel (RYR1) of the sarcoplasmic reticulum (SR) via transient protein–protein interactions. Although the molecular mechanism that underlies conformational coupling between CaV1.1 and RYR1 has been investigated intensely for more than 25 years, the question of whether such signaling occurs via a direct interaction between the principal, voltage-sensing α1S subunit of CaV1.1 and RYR1 or through an intermediary protein persists. A substantial body of evidence supports the idea that the auxiliary β1a subunit of CaV1.1 is a conduit for this intermolecular communication. However, a direct role for β1a has been difficult to test because β1a serves two other functions that are prerequisite for conformational coupling between CaV1.1 and RYR1. Specifically, β1a promotes efficient membrane expression of CaV1.1 and facilitates the tetradic ultrastructural arrangement of CaV1.1 channels within plasma membrane–SR junctions. In this paper, we demonstrate that overexpression of the RGK protein Rem, an established β subunit–interacting protein, in adult mouse flexor digitorum brevis fibers markedly reduces voltage-induced myoplasmic Ca2+ transients without greatly affecting CaV1.1 targeting, intramembrane gating charge movement, or releasable SR Ca2+ store content. In contrast, a β1a-binding–deficient Rem triple mutant (R200A/L227A/H229A) has little effect on myoplasmic Ca2+ release in response to membrane depolarization. Thus, Rem effectively uncouples the voltage sensors of CaV1.1 from RYR1-mediated SR Ca2+ release via its ability to interact with β1a. Our findings reveal Rem-expressing adult muscle as an experimental system that may prove useful in the definition of the precise role of the β1a subunit in skeletal-type EC coupling. PMID:26078055

REM optical/NIR observations of MAXI J1659-152

NARCIS (Netherlands)

D'Avanzo, P.; Goldoni, P.; Patruno, A.; Casella, P.; Campana, S.; Russell, D.M.; Belloni, T.M.

2010-01-01

We observed the optical and NIR counterpart of the recently discovered X-ray transient MAXI J1659-152 (Negoro et al. 2010, ATel #2873; Mangano et al. 2010, GCN #11296) with the REM telescope located in La Silla (Chile) in imaging mode using the V, R, I, J, H and K filters.

REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity.

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Gilson, Médhi; Deliens, Gaétane; Leproult, Rachel; Bodart, Alice; Nonclercq, Antoine; Ercek, Rudy; Peigneux, Philippe

2015-12-29

Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM) sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24) listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min) morning nap. The other half had a long (90 min) morning nap, richer in REM and N2 sleep. Story recall, mood evolution and changes in emotional response to the re-exposure to the story were assessed after the nap. Although recall performance was similar for sad and neutral stories irrespective of nap duration, sleep measures were correlated with recall performance in the sad story condition only. After the long nap, REM sleep density positively correlated with retrieval performance, while re-exposure to the sad story led to diminished mood and increased skin conductance levels. Our results suggest that REM sleep may not only be associated with the consolidation of intrinsically sad material, but also enhances mood reactivity, at least on the short term.

REM sleep enhancement and behavioral cataplexy following orexin (hypocretin)-II receptor antisense perfusion in the pontine reticular formation.

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Thakkar, M M; Ramesh, V; Cape, E G; Winston, S; Strecker, R E; McCarley, R W

1999-01-01

Orexin (hypocretin)-containing neurons of the hypothalamus project to brainstem sites that are involved in the neural control of REM sleep, including the locus coeruleus, the dorsal raphe nucleus, the cholinergic zone of the mesopontine tegmentum, and the pontine reticular formation (PRF). Orexin knockout mice exhibit narcolepsy/cataplexy, and a mutant and defective gene for the orexin type II receptor is present in dogs with an inherited form of narcolepsy/cataplexy. However, the physiological systems mediating these effects have not been described. We reasoned that, since the effector neurons for the majority of REM sleep signs, including muscle atonia, were located in the PRF, this region was likely implicated in the production of these orexin-related abnormalities. To test this possibility, we used microdialysis perfusion of orexin type II receptor antisense in the PRF of rats. Ten to 24 hours after antisense perfusion, REM sleep increased two- to three-fold during both the light period (quiescent phase) and the dark period (active phase), and infrared video showed episodes of behavioral cataplexy. Moreover, preliminary data indicated no REM-related effects following perfusion with nonsense DNA, or when perfusion sites were outside the PRF. More work is needed to provide precise localization of the most effective site of orexin-induced inhibition of REM sleep phenomena.

Hypocretin-2 saporin lesions of the ventrolateral periaquaductal gray (vlPAG increase REM sleep in hypocretin knockout mice.

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Satvinder Kaur

2009-07-01

Full Text Available Ten years ago the sleep disorder narcolepsy was linked to the neuropeptide hypocretin (HCRT, also known as orexin. This disorder is characterized by excessive day time sleepiness, inappropriate triggering of rapid-eye movement (REM sleep and cataplexy, which is a sudden loss of muscle tone during waking. It is still not known how HCRT regulates REM sleep or muscle tone since HCRT neurons are localized only in the lateral hypothalamus while REM sleep and muscle atonia are generated from the brainstem. To identify a potential neuronal circuit, the neurotoxin hypocretin-2-saporin (HCRT2-SAP was used to lesion neurons in the ventral lateral periaquaductal gray (vlPAG. The first experiment utilized hypocretin knock-out (HCRT-ko mice with the expectation that deletion of both HCRT and its target neurons would exacerbate narcoleptic symptoms. Indeed, HCRT-ko mice (n = 8 given the neurotoxin HCRT2-SAP (16.5 ng/23nl/sec each side in the vlPAG had levels of REM sleep and sleep fragmentation that were considerably higher compared to HCRT-ko given saline (+39%; n = 7 or wildtype mice (+177%; n = 9. However, cataplexy attacks did not increase, nor were levels of wake or non-REM sleep changed. Experiment 2 determined the effects in mice where HCRT was present but the downstream target neurons in the vlPAG were deleted by the neurotoxin. This experiment utilized an FVB-transgenic strain of mice where eGFP identifies GABA neurons. We verified this and also determined that eGFP neurons were immunopositive for the HCRT-2 receptor. vlPAG lesions in these mice increased REM sleep (+79% versus saline controls and it was significantly correlated (r = 0.89 with loss of eGFP neurons. These results identify the vlPAG as one site that loses its inhibitory control over REM sleep, but does not cause cataplexy, as a result of hypocretin deficiency.

A systematic search of sudden pressure drops on Gale crater during two Martian years derived from MSL/REMS data

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Ordonez-Etxeberria, Iñaki; Hueso, Ricardo; Sánchez-Lavega, Agustín

2018-01-01

nocturnal sudden pressure drops concentrate in the 20:00-23:00 LTST time interval and they only occur in spring and summer. We interpret these nocturnal events as a consequence of local mechanically forced turbulence. This interpretation is consistent with published results from simulations with the MRAMS model (Rafkin et al., 2016) that predict a competition between local orographic circulation and global Hadley cell circulation at Gale crater at summer night-time that can enhance forced turbulence at the surface. Bursts of pressure drops appear on particular sols, especially at night-time. Most of the vortex bursts occurred when MSL was in the region called Pahrump Hills characterized by a complex terrain. A comparison of the daytime pressure drops from REMS data with published results from the Pathfinder and Phoenix missions shows that the frequency of daytime events at Gale crater in spring and summer is similar to the one previously found at other locations. Finally, we present possible correlations between MSL activity and some daytime pressure drops. If such an instrumental effect is present in the REMS data its impact in this analysis is small and would only affect about 7% of our detections.

Augmented In Situ Subsurface Bioremediation Process™BIO-REM, Inc. - Demonstration Bulletin

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The Augmented In Situ Subsurface Bioremediation Process™ developed by BIO-REM, Inc., uses microaerophilic bacteria and micronutrients (H-10) and surface tension depressants/penetrants for the treatment of hydrocarbon contaminated soils and groundwater. The bacteria utilize hydroc...

A diffusion decision model analysis of evidence variability in the lexical decision task.

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Tillman, Gabriel; Osth, Adam F; van Ravenzwaaij, Don; Heathcote, Andrew

2017-12-01

The lexical-decision task is among the most commonly used paradigms in psycholinguistics. In both the signal-detection theory and Diffusion Decision Model (DDM; Ratcliff, Gomez, & McKoon, Psychological Review, 111, 159-182, 2004) frameworks, lexical-decisions are based on a continuous source of word-likeness evidence for both words and non-words. The Retrieving Effectively from Memory model of Lexical-Decision (REM-LD; Wagenmakers et al., Cognitive Psychology, 48(3), 332-367, 2004) provides a comprehensive explanation of lexical-decision data and makes the prediction that word-likeness evidence is more variable for words than non-words and that higher frequency words are more variable than lower frequency words. To test these predictions, we analyzed five lexical-decision data sets with the DDM. For all data sets, drift-rate variability changed across word frequency and non-word conditions. For the most part, REM-LD's predictions about the ordering of evidence variability across stimuli in the lexical-decision task were confirmed.

Autonomic symptoms in idiopathic REM behavior disorder

DEFF Research Database (Denmark)

Ferini-Strambi, Luigi; Oertel, Wolfgang; Dauvilliers, Yves

2014-01-01

Patients with idiopathic REM sleep behavior disorder (iRBD) are at very high risk of developing neurodegenerative synucleinopathies, which are disorders with prominent autonomic dysfunction. Several studies have documented autonomic dysfunction in iRBD, but large-scale assessment of autonomic...... symptoms has never been systematically performed. Patients with polysomnography-confirmed iRBD (318 cases) and controls (137 healthy volunteers and 181 sleep center controls with sleep diagnoses other than RBD) were recruited from 13 neurological centers in 10 countries from 2008 to 2011. A validated scale...

Non-REM sleep EEG power distribution in fatigue and sleepiness.

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Neu, Daniel; Mairesse, Olivier; Verbanck, Paul; Linkowski, Paul; Le Bon, Olivier

2014-04-01

The aim of this study is to contribute to the sleep-related differentiation between daytime fatigue and sleepiness. 135 subjects presenting with sleep apnea-hypopnea syndrome (SAHS, n=58) or chronic fatigue syndrome (CFS, n=52) with respective sleepiness or fatigue complaints and a control group (n=25) underwent polysomnography and psychometric assessments for fatigue, sleepiness, affective symptoms and perceived sleep quality. Sleep EEG spectral analysis for ultra slow, delta, theta, alpha, sigma and beta power bands was performed on frontal, central and occipital derivations. Patient groups presented with impaired subjective sleep quality and higher affective symptom intensity. CFS patients presented with highest fatigue and SAHS patients with highest sleepiness levels. All groups showed similar total sleep time. Subject groups mainly differed in sleep efficiency, wake after sleep onset, duration of light sleep (N1, N2) and slow wave sleep, as well as in sleep fragmentation and respiratory disturbance. Relative non-REM sleep power spectra distributions suggest a pattern of power exchange in higher frequency bands at the expense of central ultra slow power in CFS patients during all non-REM stages. In SAHS patients, however, we found an opposite pattern at occipital sites during N1 and N2. Slow wave activity presents as a crossroad of fatigue and sleepiness with, however, different spectral power band distributions during non-REM sleep. The homeostatic function of sleep might be compromised in CFS patients and could explain why, in contrast to sleepiness, fatigue does not resolve with sleep in these patients. The present findings thus contribute to the differentiation of both phenomena. Copyright © 2014 Elsevier Inc. All rights reserved.

REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity

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Médhi Gilson

2015-12-01

Full Text Available Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24 listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min morning nap. The other half had a long (90 min morning nap, richer in REM and N2 sleep. Story recall, mood evolution and changes in emotional response to the re-exposure to the story were assessed after the nap. Although recall performance was similar for sad and neutral stories irrespective of nap duration, sleep measures were correlated with recall performance in the sad story condition only. After the long nap, REM sleep density positively correlated with retrieval performance, while re-exposure to the sad story led to diminished mood and increased skin conductance levels. Our results suggest that REM sleep may not only be associated with the consolidation of intrinsically sad material, but also enhances mood reactivity, at least on the short term.

Is a purpose of REM sleep atonia to help regenerate intervertebral disc volumetric loss?

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Fryer Jerome CJ

2009-01-01

Full Text Available Abstract The nature of atonia in sleep continues to be enigmatic. This article discusses a new hypothesis for complete core muscle relaxation in REM sleep, suggesting a bottom-up recuperative perspective. That is, does the atonia in REM sleep provide a utility to help restore the mechanobiology and respective diurnal intervertebral disc hydraulic loss? By combining the effects of gravity with current compressive concepts in spinal stability, this article looks at vertebral approximation as a deleterious experience with an intrinsic biological need to keep vertebrae separated. Methods using polysomnography and recumbent MRI are discussed.

Operator product expansion in Liouville field theory and Seiberg-type transitions in log-correlated random energy models

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Cao, Xiangyu; Le Doussal, Pierre; Rosso, Alberto; Santachiara, Raoul

2018-04-01

We study transitions in log-correlated random energy models (logREMs) that are related to the violation of a Seiberg bound in Liouville field theory (LFT): the binding transition and the termination point transition (a.k.a., pre-freezing). By means of LFT-logREM mapping, replica symmetry breaking and traveling-wave equation techniques, we unify both transitions in a two-parameter diagram, which describes the free-energy large deviations of logREMs with a deterministic background log potential, or equivalently, the joint moments of the free energy and Gibbs measure in logREMs without background potential. Under the LFT-logREM mapping, the transitions correspond to the competition of discrete and continuous terms in a four-point correlation function. Our results provide a statistical interpretation of a peculiar nonlocality of the operator product expansion in LFT. The results are rederived by a traveling-wave equation calculation, which shows that the features of LFT responsible for the transitions are reproduced in a simple model of diffusion with absorption. We examine also the problem by a replica symmetry breaking analysis. It complements the previous methods and reveals a rich large deviation structure of the free energy of logREMs with a deterministic background log potential. Many results are verified in the integrable circular logREM, by a replica-Coulomb gas integral approach. The related problem of common length (overlap) distribution is also considered. We provide a traveling-wave equation derivation of the LFT predictions announced in a precedent work.

REM Desensitization as a New Therapeutic Method for Post- Traumatic Stress Disorder: A Randomized Controlled Trial

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Khodabakhsh Ahmadi

2016-05-01

Full Text Available Aim: to evaluate potential efficacy of a new therapeutic approach in posttraumatic stress disorder in comparison with eye movement desensitization and reprocessing (EMDR, a standard treatment approach and controls. Methods: the study was designed using a randomized controlled trial methodology. Participants were recruited from military servicemen aged between 25 to 50 years who were admitting hospitals of Bushehr, Iran, with the final diagnosis of PTSD. Finally 33 male patients were devided into three subgroups: G1: EMDR; G2: REM Desensitization; and group 3: controls who received no therapy. Mississippi Scale for Posttraumatic Stress Disorder, Pittsburgh Sleep Quality Index (PSQI and a 37 item death anxiety questionnaire were used for measures. Results: multiple comparisons showed that intrusive thoughts were significantly more likely to improve with REM Desensitization versus EMDR (P=0.03, while depression was more responsive to EMDR (p=0.03. Among the Pittsburgh scale for the quality of sleep items, sleep quality (p=0.02, sleep duration (p=0.001, and total sleep quality score (p=0.002 were significantly more likely to improve in the REM Desensitization group. Change in the absolute death anxiety scores was not different between subgroups excepting EMDR versus control group (p=0.05. Conclusion: REM, desensitization, the new therapeutic approach to PTSD is a highly effective strategy, even more than EMDR, the standard treatment, in most of the evaluated subjects, with special emphasis on sleep symptoms, and also in the management of intrusive thoughts. Depression is the only factor in which, REM Desensitization was significantly less likely to represent a superior therapeutic effect than EMDR. Key words: post traumatic stress disorder (PTSD, eye movement desensitization and reprocessing, new treatment.

Alpha reactivity to complex sounds differs during REM sleep and wakefulness.

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Perrine Ruby

Full Text Available We aimed at better understanding the brain mechanisms involved in the processing of alerting meaningful sounds during sleep, investigating alpha activity. During EEG acquisition, subjects were presented with a passive auditory oddball paradigm including rare complex sounds called Novels (the own first name - OWN, and an unfamiliar first name - OTHER while they were watching a silent movie in the evening or sleeping at night. During the experimental night, the subjects' quality of sleep was generally preserved. During wakefulness, the decrease in alpha power (8-12 Hz induced by Novels was significantly larger for OWN than for OTHER at parietal electrodes, between 600 and 900 ms after stimulus onset. Conversely, during REM sleep, Novels induced an increase in alpha power (from 0 to 1200 ms at all electrodes, significantly larger for OWN than for OTHER at several parietal electrodes between 700 and 1200 ms after stimulus onset. These results show that complex sounds have a different effect on the alpha power during wakefulness (decrease and during REM sleep (increase and that OWN induce a specific effect in these two states. The increased alpha power induced by Novels during REM sleep may 1 correspond to a short and transient increase in arousal; in this case, our study provides an objective measure of the greater arousing power of OWN over OTHER, 2 indicate a cortical inhibition associated with sleep protection. These results suggest that alpha modulation could participate in the selection of stimuli to be further processed during sleep.

Schiphol - üks saar muudab Hollandi / Rem Koolhaas ; tõlk. Inga Raukas

Index Scriptorium Estoniae

Koolhaas, Rem, 1944-

2000-01-01

Schipholi lennuvälja ümberpaigutamine kunstlikule saarele meres. Hollandi arhitektuuribüroo OMA arhitektuurse projekti kirjeldus. Projekteerijad Rem Koolhaas, Reinier de Graaf, Jens Hommert, Mateo Poli, Adam Kurdahl, Anna Little, Bert Karel Deuten. 23 ill

Cholinergic Oculomotor Nucleus Activity Is Induced by REM Sleep Deprivation Negatively Impacting on Cognition.

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Santos, Patrícia Dos; Targa, Adriano D S; Noseda, Ana Carolina D; Rodrigues, Lais S; Fagotti, Juliane; Lima, Marcelo M S

2017-09-01

Several efforts have been made to understand the involvement of rapid eye movement (REM) sleep for cognitive processes. Consolidation or retention of recognition memories is severely disrupted by REM sleep deprivation (REMSD). In this regard, pedunculopontine tegmental nucleus (PPT) and other brainstem nuclei, such as pontine nucleus (Pn) and oculomotor nucleus (OCM), appear to be candidates to take part in this REM sleep circuitry with potential involvement in cognition. Therefore, the objective of this study was to investigate a possible association between the performance of Wistar rats in a declarative memory and PPT, Pn, and OCM activities after different periods of REMSD. We examined c-Fos and choline acetyltransferase (ChaT) expressions as indicators of neuronal activity as well as a familiarity-based memory test. The animals were distributed in groups: control, REMSD, and sleep rebound (REB). At the end of the different REMSD (24, 48, 72, and 96 h) and REB (24 h) time points, the rats were immediately tested in the object recognition test and then the brains were collected. Results indicated that OCM neurons presented an increased activity, due to ChaT-labeling associated with REMSD that negatively correlated (r = -0.32) with the cognitive performance. This suggests the existence of a cholinergic compensatory mechanism within the OCM during REMSD. We also showed that 24 h of REMSD impacted similarly in memory, compared to longer periods of REMSD. These data extend the notion that REM sleep is influenced by areas other than PPT, i.e., Pn and OCM, which could be key players in both sleep processes and cognition.

A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population.

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Mellman, Thomas A; Kobayashi, Ihori; Lavela, Joseph; Wilson, Bryonna; Hall Brown, Tyish S

2014-08-01

To determine relationships of polysomnographic (PSG) measures with posttraumatic stress disorder (PTSD) in a young adult, urban African American population. Cross-sectional, clinical and laboratory evaluation. Community recruitment, evaluation in the clinical research unit of an urban University hospital. Participants (n = 145) were Black, 59.3% female, with a mean age of 23.1 y (SD = 4.8). One hundred twenty-one participants (83.4%) met criteria for trauma exposure, the most common being nonsexual violence. Thirty-nine participants (26.9%) met full (n = 19) or subthreshold criteria (n = 20) for current PTSD, 41 (28.3%) had met lifetime PTSD criteria and were recovered, and 65 (45%) were negative for PTSD. Evaluations included the Clinician Administered PTSD Scale (CAPS) and 2 consecutive nights of overnight PSG. Analysis of variance did not reveal differences in measures of sleep duration and maintenance, percentage of sleep stages, and the latency to and duration of uninterrupted segments of rapid eye movement (REM) sleep by study group. There were significant relationships between the duration of PTSD and REM sleep percentage (r = 0.53, P = 0.001), REM segment length (r = 0.43, P = 0.006), and REM sleep latency (r = -0.34, P sleep with posttraumatic stress disorder (PTSD) relatively proximate to trauma exposure and nondisrupted or increased REM sleep with chronic PTSD. Mellman TA, Kobayashi I, Lavela J, Wilson B, Hall Brown TS. A relationship between REM sleep measures and the duration of posttraumatic stress disorder in a young adult urban minority population.

Olfactory impairment in the rotenone model of Parkinson's disease is associated with bulbar dopaminergic D2 activity after REM sleep deprivation

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Laís Soares Rodrigues

2014-12-01

Full Text Available Olfactory and rapid eye movement (REM sleep deficits are commonly found in untreated subjects with a recent diagnosis of Parkinson's disease (PD. Besides different studies reported declines in olfactory performances during a short period of sleep deprivation. Mechanisms underlying these clinical manifestations are poorly understood although the impairment in the dopamine (DA neurotransmission in the olfactory bulb and in the nigrostriatal pathway may have important roles in olfactory as well as in REM sleep disturbances. Therefore, we have led to the hypothesis that a modulation of the dopaminergic D2 receptors in the olfactory bulb could provide a more comprehensive understanding of the olfactory deficits in PD and after a short period of REM sleep deprivation (REMSD. We decided to investigate the olfactory, neurochemical and histological alterations generated by the administration of piribedil (a selective D2 agonist or raclopride (a selective D2 antagonist, within the glomerular layer of the olfactory bulb, in rats submitted to intranigral rotenone and REMSD. Our findings provided a remarkable evidence of the occurrence of a negative correlation (r = - 0.52, P = 0.04 between the number of periglomerular TH-ir neurons and the bulbar levels of DA in the rotenone, but not sham groups. A significant positive correlation (r = 0.34, P = 0.03 was observed between nigral DA and olfactory discrimination index (DI, for the sham groups, indicating that increased DA levels in the substantia nigra pars compacta (SNpc are associated to enhanced olfactory discrimination performance. Also, increased levels in bulbar and striatal DA induced by piribedil in the rotenone control and rotenone REMSD groups were consistent with reduced amounts of DI. The present evidence reinforce that DA produced by periglomerular neurons, and particularly the bulbar dopaminergic D2 receptors, are essential participants in the olfactory discrimination processes, as well as SNpc

Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep

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Francisco J Urbano

2014-10-01

Full Text Available The pedunculopontine nucleus (PPN is a major component of the reticular activating system (RAS that regulates waking and REM sleep, states of high frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine pedunculopontine nucleus (PPN, intralaminar parafascicular nucleus (Pf, and pontine Subcoeruleus nucleus dorsalis (SubCD. Cortical gamma band activity participates in sensory perception, problem solving, and memory. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. That is, the RAS may play an early permissive role in volition. Our latest results suggest that, 1 the manifestation of gamma band activity during waking may employ a separate intracellular pathway compared to that during REM sleep, 2 neuronal calcium sensor (NCS-1 protein, which is over expressed in schizophrenia and bipolar disorder, modulates gamma band oscillations in the PPN in a concentration-dependent manner, 3 leptin, which undergoes resistance in obesity resulting in sleep dysregulation, decreases sodium currents in PPN neurons, accounting for its normal attenuation of waking, and 4 following our discovery of electrical coupling in the RAS, we hypothesize that there are cell clusters within the PPN that may act in concert. These results provide novel information on the mechanisms controlling high frequency activity related to waking and REM sleep by elements of the RAS.

A differentiating empirical linguistic analysis of dreamer activity in reports of EEG-controlled REM-dreams and hypnagogic hallucinations.

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Speth, Jana; Frenzel, Clemens; Voss, Ursula

2013-09-01

We present Activity Analysis as a new method for the quantification of subjective reports of altered states of consciousness with regard to the indicated level of simulated motor activity. Empirical linguistic activity analysis was conducted with dream reports conceived immediately after EEG-controlled periods of hypnagogic hallucinations and REM-sleep in the sleep laboratory. Reports of REM-dreams exhibited a significantly higher level of simulated physical dreamer activity, while hypnagogic hallucinations appear to be experienced mostly from the point of passive observer. This study lays the groundwork for clinical research on the level of simulated activity in pathologically altered states of subjective experience, for example in the REM-dreams of clinically depressed patients, or in intrusions and dreams of patients diagnosed with PTSD. Copyright © 2013 Elsevier Inc. All rights reserved.

Personal dose assessment using region of interest analysis compared with harshaw TLD WinREMS software evaluation

International Nuclear Information System (INIS)

Adjei, D.

2010-06-01

Personal dose equivalents, Hp(10), have been evaluated manually using Region of Interest (ROI) analysis and compared with the automated computerized WinREMS software for the occupationally exposed in medical, industrial and research/teaching applications for 2008 and 2009. The mean annual effective dose estimated by the WinREMS software for medical, industrial and research/teaching applications for the study period are 0.459 mSv, 0.549mSv and 0.447 mSv, respectively compared with ROI analysis are 0.424 mSv, 0.520 mSv and 0.407 mSv respectively. The mean annual collective doses evaluated by the WinREMS software for medical, industrial and research/teaching applications for the two-year study period are 0.258 man-Sv, 0.084 man-Sv and 0.032 man-Sv respectively, compared with the ROI analysis with values: 0.238 man-Sv, 0.080 man-Sv and 0.029 man-Sv respectively. The individual doses for the occupationally exposed in Ghana fall within the typical range of individual doses in the UNSCEAR 2008 report. In calibration mode, the WinREMS method overestimated the personal dose equivalent by 51.3% for doses below 1 mSv and 12.0% above 1 mSv. The corresponding values for the Region of Interest analysis method are 13.2% and 6.5%. The results from the study indicate that the ROI analysis provides a better alternative to estimating the personal doses (au).

Privação de sono REM em um modelo experimental da doença de Parkinson

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Luiz A. F. Andrade

1987-09-01

Full Text Available Investigação prévia mostrou que ratos privados de sono (REM SD mostram acentuação de resposta a agonistas dopaminérgicos. As evidências indicam que essa ação parece ser mediada por supersensibilização de receptores dopaminérgicos pós-sinápticos. Com base nisso, foi feita REM SD em ratos com modelo experimental da doença de Parkinson, nos quais foi feita lesão eletrolítica bilateral de ambas as vias nigro-estriatais. Sete dias após a cirurgia os animais eram submetidos a REM SD por 72 horas. Imediatamente após o final deste período era feita observação em campo aberto para a ambulação, "rearing", "grooming" e latência. Em comparação com ratos não-privados foi observado aumento significativo na ambulação e "rearing", resposta que reapareceu após um segundo período de REM SD, realizado 21 dias após a cirurgia. Estes dados, de melhora de dois parâmetros de modelo experimental da doença de Parkinson, sugerem que a privação de sono pode ser útil nesta doença.

Complex sound processing during human REM sleep by recovering information from long-term memory as revealed by the mismatch negativity (MMN).

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Atienza, M; Cantero, J L

2001-05-18

Perceptual learning is thought to be the result of neural changes that take place over a period of several hours or days, allowing information to be transferred to long-term memory. Evidence suggests that contents of long-term memory may improve attentive and pre-attentive sensory processing. Therefore, it is plausible to hypothesize that learning-induced neural changes that develop during wakefulness could improve automatic information processing during human REM sleep. The MMN, an objective measure of the automatic change detection in auditory cortex, was used to evaluate long-term learning effects on pre-attentive processing during wakefulness and REM sleep. When subjects learned to discriminate two complex auditory patterns in wakefulness, an increase in the MMN was obtained in both wake and REM states. The automatic detection of the infrequent complex auditory pattern may therefore be improved in both brain states by reactivating information from long-term memory. These findings suggest that long-term learning-related neural changes are accessible during REM sleep as well.

Combining weather radar nowcasts and numerical weather prediction models to estimate short-term quantitative precipitation and uncertainty

DEFF Research Database (Denmark)

Jensen, David Getreuer

The topic of this Ph.D. thesis is short term forecasting of precipitation for up to 6 hours called nowcasts. The focus is on improving the precision of deterministic nowcasts, assimilation of radar extrapolation model (REM) data into Danish Meteorological Institutes (DMI) HIRLAM numerical weather...

Disappearance of "phantom limb" and amputated arm usage during dreaming in REM sleep behaviour disorder.

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Vetrugno, Roberto; Arnulf, Isabelle; Montagna, Pasquale

2009-01-01

Limb amputation is followed, in approximately 90% of patients, by "phantom limb" sensations during wakefulness. When amputated patients dream, however, the phantom limb may be present all the time, part of the time, intermittently or not at all. Such dreaming experiences in amputees have usually been obtained only retrospectively in the morning and, moreover, dreaming is normally associated with muscular atonia so the motor counterpart of the phantom limb experience cannot be observed directly. REM sleep behaviour disorder (RBD), in which muscle atonia is absent during REM sleep and patients act out their dreams, allows a more direct analysis of the "phantom limb" phenomena and their modifications during sleep.

Sleep board review questions: sleep disordered breathing that improves in REM

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Budhiraja R

2012-08-01

Full Text Available No abstract available. Article truncated at end of question. Which of the following breathing disorders is usually less severe in rapid eye movement (REM sleep compared to non-rapid eye movement (NREM sleep?1.Sleep-related hypoxemia in COPD2.Obstructive Sleep Apnea3.Cheyne Stokes Breathing4.Hypoxemia in Pulmonary Hypertension

Comparisons Between Model Predictions and Spectral Measurements of Charged and Neutral Particles on the Martian Surface

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Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F.; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan;

Rapid-Eye-Movement-Sleep (REM Associated Enhancement of Working Memory Performance after a Daytime Nap.

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Esther Yuet Ying Lau

Full Text Available The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40 or stay awake (Wake-group, n=40 between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression, which are also presented with cognitive dysfunctions (e.g. working memory deficits, this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy.

Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap

Science.gov (United States)

Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei

2015-01-01

The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that “sleep gain” during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy. PMID:25970511

Why Does REM Sleep Occur? A Wake-up Hypothesis

OpenAIRE

Dr. W. R. eKlemm

2011-01-01

Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses REM to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, 1) when first going to sleep, the brain plunges into Stage N3 (formerly ca...

State- or trait-like individual differences in dream recall: Preliminary findings from a within-subjects study of multiple nap REM sleep awakenings

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Serena eScarpelli

2015-07-01

Full Text Available We examined the question whether the role of EEG oscillations in predicting presence/absence of dream recall (DR is explained by state- or trait-like factors. Six healthy subjects were awakened from REM sleep in a within-subjects design with multiple naps, until a recall (REC and a non-recall (NREC condition were obtained. Naps were scheduled in the early afternoon and were separated by one week. Topographical EEG data of the 5-min of REM sleep preceding each awakening were analyzed by power spectral analysis [Fast Fourier Transform (FFT] and by a method to detect oscillatory activity [Better OSCillations (BOSC].Both analyses show that REC is associated to higher frontal theta activity (5-7 Hz and theta oscillations (6.06 Hz compared to NREC condition, but only the second comparison reached significance. Our pilot study provides support to the notion that sleep and wakefulness share similar EEG correlates of encoding in episodic memories, and supports the state-like hypothesis: dream recall may depend on the physiological state related to the sleep stage from which the subject is awakened rather than on a stable individual EEG pattern.

A Model for Evidence Accumulation in the Lexical Decision Task

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Wagenmakers, Eric-Jan; Steyvers, Mark; Raaijmakers, Jeroen G. W.; Shiffrin, Richard M.; van Rijn, Hedderik; Zeelenberg, Rene

2004-01-01

We present a new model for lexical decision, REM-LD, that is based on REM theory (e.g., Shiffrin & Steyvers, 1997). REM-LD uses a principled (i.e., Bayes' rule) decision process that simultaneously considers the diagnosticity of the evidence for the 'WORD' response and the 'NONWORD' response. The model calculates the odds ratio that the presented…

Neural correlates of dream lucidity obtained from contrasting lucid versus non-lucid REM sleep: a combined EEG/fMRI case study.

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Dresler, Martin; Wehrle, Renate; Spoormaker, Victor I; Koch, Stefan P; Holsboer, Florian; Steiger, Axel; Obrig, Hellmuth; Sämann, Philipp G; Czisch, Michael

2012-07-01

To investigate the neural correlates of lucid dreaming. Parallel EEG/fMRI recordings of night sleep. Sleep laboratory and fMRI facilities. Four experienced lucid dreamers. N/A. Out of 4 participants, one subject had 2 episodes of verified lucid REM sleep of sufficient length to be analyzed by fMRI. During lucid dreaming the bilateral precuneus, cuneus, parietal lobules, and prefrontal and occipito-temporal cortices activated strongly as compared with non-lucid REM sleep. In line with recent EEG data, lucid dreaming was associated with a reactivation of areas which are normally deactivated during REM sleep. This pattern of activity can explain the recovery of reflective cognitive capabilities that are the hallmark of lucid dreaming.

Fear Extinction Memory Consolidation Requires Potentiation of Pontine-Wave Activity during REM Sleep

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Datta, Subimal; O'Malley, Matthew W .

2013-01-01

Sleep plays an important role in memory consolidation within multiple memory systems including contextual fear extinction memory, but little is known about the mechanisms that underlie this process. Here, we show that fear extinction training in rats, which extinguished conditioned fear, increased both slow-wave sleep and rapid-eye movement (REM) sleep. Surprisingly, 24 h later, during memory testing, only 57% of the fear-extinguished animals retained fear extinction memory. We found that these animals exhibited an increase in phasic pontine-wave (P-wave) activity during post-training REM sleep, which was absent in the 43% of animals that failed to retain fear extinction memory. The results of this study provide evidence that brainstem activation, specifically potentiation of phasic P-wave activity, during post-training REM sleep is critical for consolidation of fear extinction memory. The results of this study also suggest that, contrary to the popular hypothesis of sleep and memory, increased sleep after training alone does not guarantee consolidation and/or retention of fear extinction memory. Rather, the potentiation of specific sleep-dependent physiological events may be a more accurate predictor for successful consolidation of fear extinction memory. Identification of this unique mechanism will significantly improve our present understanding of the cellular and molecular mechanisms that underlie the sleep-dependent regulation of emotional memory. Additionally, this discovery may also initiate development of a new, more targeted treatment method for clinical disorders of fear and anxiety in humans that is more efficacious than existing methods such as exposure therapy that incorporate only fear extinction. PMID:23467372

Bootstrap prediction and Bayesian prediction under misspecified models

OpenAIRE

Fushiki, Tadayoshi

2005-01-01

We consider a statistical prediction problem under misspecified models. In a sense, Bayesian prediction is an optimal prediction method when an assumed model is true. Bootstrap prediction is obtained by applying Breiman's `bagging' method to a plug-in prediction. Bootstrap prediction can be considered to be an approximation to the Bayesian prediction under the assumption that the model is true. However, in applications, there are frequently deviations from the assumed model. In this paper, bo...

REM sleep deprivation induces endothelial dysfunction and hypertension in middle-aged rats: Roles of the eNOS/NO/cGMP pathway and supplementation with L-arginine.

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Jiang, Jiaye; Gan, Zhongyuan; Li, Yuan; Zhao, Wenqi; Li, Hanqing; Zheng, Jian-Pu; Ke, Yan

2017-01-01

Sleep loss can induce or aggravate the development of cardiovascular and cerebrovascular diseases. However, the molecular mechanism underlying this phenomenon is poorly understood. The present study was designed to investigate the effects of REM sleep deprivation on blood pressure in rats and the underlying mechanisms of these effects. After Sprague-Dawley rats were subjected to REM sleep deprivation for 5 days, their blood pressures and endothelial function were measured. In addition, one group of rats was given continuous access to L-arginine supplementation (2% in distilled water) for the 5 days before and the 5 days of REM sleep deprivation to reverse sleep deprivation-induced pathological changes. The results showed that REM sleep deprivation decreased body weight, increased blood pressure, and impaired endothelial function of the aortas in middle-aged rats but not young rats. Moreover, nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) concentrations as well as endothelial NO synthase (eNOS) phosphorylation in the aorta were decreased by REM sleep deprivation. Supplementation with L-arginine could protect against REM sleep deprivation-induced hypertension, endothelial dysfunction, and damage to the eNOS/NO/cGMP signaling pathway. The results of the present study suggested that REM sleep deprivation caused endothelial dysfunction and hypertension in middle-aged rats via the eNOS/NO/cGMP pathway and that these pathological changes could be inhibited via L-arginine supplementation. The present study provides a new strategy to inhibit the signaling pathways involved in insomnia-induced or insomnia-enhanced cardiovascular diseases.

Why Does Rem Sleep Occur? A Wake-Up Hypothesis 1

OpenAIRE

Klemm, W. R.

2011-01-01

Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses rapid eye movement (REM) to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, (1) when first going to sleep, the brain plunges into ...

Normal Morning MCH Levels and No Association with REM or NREM Sleep Parameters in Narcolepsy Type 1 and Type 2

DEFF Research Database (Denmark)

Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen

2017-01-01

in rapid eye movement (REM) and nonrapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid...... MCH levels. CONCLUSION: Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH......STUDY OBJECTIVES: Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved...

Predictive Modelling and Time: An Experiment in Temporal Archaeological Predictive Models

OpenAIRE

David Ebert

2006-01-01

One of the most common criticisms of archaeological predictive modelling is that it fails to account for temporal or functional differences in sites. However, a practical solution to temporal or functional predictive modelling has proven to be elusive. This article discusses temporal predictive modelling, focusing on the difficulties of employing temporal variables, then introduces and tests a simple methodology for the implementation of temporal modelling. The temporal models thus created ar...

UV production of methane from surface and sedimenting IDPs on Mars in light of REMS data and with insights for TGO

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Moores, John E.; Smith, Christina L.; Schuerger, Andrew C.

2017-11-01

This paper refines model predictions for the production of methane from UV-irradiated interplanetary dust particles (IDPs) now that the Rover Environmental Monitoring Station (REMS) instrument onboard the Mars Science Laboratory (MSL) Rover has made the first measurements of the UV environment on the surface of Mars, at Gale Crater. Once these measurements are included in a UV radiative transfer model, we find that modelled UV sol-integrated energies across the planet are lower than pre-measurement estimates by 35% on average, considering all latitudes and seasons. This reduction, in turn, reduces the predicted production of methane from individual accreting IDPs, extending their lifetimes and increasing the surface concentration of organics that must accumulate in order to emit sufficient methane to balance the accretion of organic compounds to Mars. Emission from reasonable accumulations of IDPs could range up to ∼7.9 × 10-4 ppbv sol-1. Richer deposits of organic carbon at the surface may emit methane at no more than 3.9 ppbv sol-1. An examination of IDP-derived methane production during atmospheric settling indicates that no more than 0.32% of organic carbon from meteor streams may be deposited in the atmosphere. Thus, such a process cannot explain either the spikes observed in methane nor the low equilibrium values observed by MSL. Instead, this discrepancy may be explained if geographical and vertical distribution will be an important input for models attempting to understand the results to be derived from the Trace Gas Orbiter (TGO) mission that will map methane concentrations in the martian atmosphere in 2018 at 0.01 ppbv.

Sociality Affects REM Sleep Episode Duration Under Controlled Laboratory Conditions in the Rock Hyrax, Procavia capensis

Directory of Open Access Journals (Sweden)

Nadine Gravett

2017-11-01

Full Text Available The rock hyrax, Procavia capensis, is a highly social, diurnal mammal. In the current study several physiologically measurable parameters of sleep, as well as the accompanying behavior, were recorded continuously from five rock hyraxes, for 72 h under solitary (experimental animal alone in the recording chamber, and social conditions (experimental animal with 1 or 2 additional, non-implanted animals in the recording chamber. The results revealed no significant differences between solitary and social conditions for total sleep times, number of episodes, episode duration or slow wave activity (SWA for all states examined. The only significant difference observed between social and solitary conditions was the average duration of rapid eye movement (REM sleep episodes. REM sleep episode duration was on average 20 s and 40 s longer under social conditions daily and during the dark period, respectively. It is hypothesized that the increase in REM sleep episode duration under social conditions could possibly be attributed to improved thermoregulation strategies, however considering the limited sample size and design of the current study further investigations are needed to confirm this finding. Whether the conclusions and the observations made in this study can be generalized to all naturally socially sleeping mammals remains an open question.

Role of REM Sleep, Melanin Concentrating Hormone and Orexin/Hypocretin Systems in the Sleep Deprivation Pre-Ischemia.

Science.gov (United States)

Pace, Marta; Adamantidis, Antoine; Facchin, Laura; Bassetti, Claudio

2017-01-01

Sleep reduction after stroke is linked to poor recovery in patients. Conversely, a neuroprotective effect is observed in animals subjected to acute sleep deprivation (SD) before ischemia. This neuroprotection is associated with an increase of the sleep, melanin concentrating hormone (MCH) and orexin/hypocretin (OX) systems. This study aims to 1) assess the relationship between sleep and recovery; 2) test the association between MCH and OX systems with the pathological mechanisms of stroke. Sprague-Dawley rats were assigned to four experimental groups: (i) SD_IS: SD performed before ischemia; (ii) IS: ischemia; (iii) SD_Sham: SD performed before sham surgery; (iv) Sham: sham surgery. EEG and EMG were recorded. The time-course of the MCH and OX gene expression was measured at 4, 12, 24 hours and 3, 4, 7 days following ischemic surgery by qRT-PCR. A reduction of infarct volume was observed in the SD_IS group, which correlated with an increase of REM sleep observed during the acute phase of stroke. Conversely, the IS group showed a reduction of REM sleep. Furthermore, ischemia induces an increase of MCH and OX systems during the acute phase of stroke, although, both systems were still increased for a long period of time only in the SD_IS group. Our data indicates that REM sleep may be involved in the neuroprotective effect of SD pre-ischemia, and that both MCH and OX systems were increased during the acute phase of stroke. Future studies should assess the role of REM sleep as a prognostic marker, and test MCH and OXA agonists as new treatment options in the acute phase of stroke.

Role of REM Sleep, Melanin Concentrating Hormone and Orexin/Hypocretin Systems in the Sleep Deprivation Pre-Ischemia.

Directory of Open Access Journals (Sweden)

Marta Pace

Full Text Available Sleep reduction after stroke is linked to poor recovery in patients. Conversely, a neuroprotective effect is observed in animals subjected to acute sleep deprivation (SD before ischemia. This neuroprotection is associated with an increase of the sleep, melanin concentrating hormone (MCH and orexin/hypocretin (OX systems. This study aims to 1 assess the relationship between sleep and recovery; 2 test the association between MCH and OX systems with the pathological mechanisms of stroke.Sprague-Dawley rats were assigned to four experimental groups: (i SD_IS: SD performed before ischemia; (ii IS: ischemia; (iii SD_Sham: SD performed before sham surgery; (iv Sham: sham surgery. EEG and EMG were recorded. The time-course of the MCH and OX gene expression was measured at 4, 12, 24 hours and 3, 4, 7 days following ischemic surgery by qRT-PCR.A reduction of infarct volume was observed in the SD_IS group, which correlated with an increase of REM sleep observed during the acute phase of stroke. Conversely, the IS group showed a reduction of REM sleep. Furthermore, ischemia induces an increase of MCH and OX systems during the acute phase of stroke, although, both systems were still increased for a long period of time only in the SD_IS group.Our data indicates that REM sleep may be involved in the neuroprotective effect of SD pre-ischemia, and that both MCH and OX systems were increased during the acute phase of stroke. Future studies should assess the role of REM sleep as a prognostic marker, and test MCH and OXA agonists as new treatment options in the acute phase of stroke.

Rem Koolhaas. Utopie ve sférách globálního trhu

Czech Academy of Sciences Publication Activity Database

Hnídková, Vendula

-, Č. 19-20 (2006), s. 212-214 ISSN 1210-6887 Institutional research plan: CEZ:AV0Z80330511 Keywords : Rem Koolhaas * contemporary architecture * utopia of architectural production Subject RIV: AL - Art, Architecture, Cultural Heritage

In-Home Sleep Recordings in Military Veterans With Posttraumatic Stress Disorder Reveal Less REM and Deep Sleep <1 Hz

Directory of Open Access Journals (Sweden)

Julie A. Onton

2018-05-01

Full Text Available Veterans with posttraumatic stress disorder (PTSD often report suboptimal sleep quality, often described as lack of restfulness for unknown reasons. These experiences are sometimes difficult to objectively quantify in sleep lab assessments. Here, we used a streamlined sleep assessment tool to record in-home 2-channel electroencephalogram (EEG with concurrent collection of electrodermal activity (EDA and acceleration. Data from a single forehead channel were transformed into a whole-night spectrogram, and sleep stages were classified using a fully automated algorithm. For this study, 71 control subjects and 60 military-related PTSD subjects were analyzed for percentage of time spent in Light, Hi Deep (1–3 Hz, Lo Deep (<1 Hz, and rapid eye movement (REM sleep stages, as well as sleep efficiency and fragmentation. The results showed a significant tendency for PTSD sleepers to spend a smaller percentage of the night in REM (p < 0.0001 and Lo Deep (p = 0.001 sleep, while spending a larger percentage of the night in Hi Deep (p < 0.0001 sleep. The percentage of combined Hi+Lo Deep sleep did not differ between groups. All sleepers usually showed EDA peaks during Lo, but not Hi, Deep sleep; however, PTSD sleepers were more likely to lack EDA peaks altogether, which usually coincided with a lack of Lo Deep sleep. Linear regressions with all subjects showed that a decreased percentage of REM sleep in PTSD sleepers was accounted for by age, prazosin, SSRIs and SNRIs (p < 0.02, while decreased Lo Deep and increased Hi Deep in the PTSD group could not be accounted for by any factor in this study (p < 0.005. Linear regression models with only the PTSD group showed that decreased REM correlated with self-reported depression, as measured with the Depression, Anxiety, and Stress Scales (DASS; p < 0.00001. DASS anxiety was associated with increased REM time (p < 0.0001. This study shows altered sleep patterns in sleepers with PTSD that can be partially accounted

FDG PET, Dopamine Transporter SPECT, and Olfaction: Combining Biomarkers in REM Sleep Behavior Disorder

NARCIS (Netherlands)

Meles, Sanne K.; Vadasz, David; Renken, Remco J.; Sittig-Wiegand, Elisabeth; Mayer, Geert; Depboylu, Candan; Reetz, Kathrin; Overeem, Sebastiaan; Pijpers, Angelique; Reesink, Fransje E.; van Laar, Teus; Heinen, Lisette; Teune, Laura K.; Höffken, Helmut; Luster, Marcus; Kesper, Karl; Adriaanse, Sofie M.; Booij, Jan; Leenders, Klaus L.; Oertel, Wolfgang H.

2017-01-01

Background: Idiopathic REM sleep behavior disorder is a prodromal stage of Parkinson's disease and dementia with Lewy bodies. Hyposmia, reduced dopamine transporter binding, and expression of the brain metabolic PD-related pattern were each associated with increased risk of conversion to PD. The

An accurate and portable solid state neutron rem meter

Energy Technology Data Exchange (ETDEWEB)

Oakes, T.M. [Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO (United States); Bellinger, S.L. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS (United States); Miller, W.H. [Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO (United States); Missouri University Research Reactor, Columbia, MO (United States); Myers, E.R. [Department of Physics, University of Missouri, Kansas City, MO (United States); Fronk, R.G.; Cooper, B.W [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS (United States); Sobering, T.J. [Electronics Design Laboratory, Kansas State University, KS (United States); Scott, P.R. [Department of Physics, University of Missouri, Kansas City, MO (United States); Ugorowski, P.; McGregor, D.S; Shultis, J.K. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS (United States); Caruso, A.N., E-mail: carusoan@umkc.edu [Department of Physics, University of Missouri, Kansas City, MO (United States)

2013-08-11

Accurately resolving the ambient neutron dose equivalent spanning the thermal to 15 MeV energy range with a single configuration and lightweight instrument is desirable. This paper presents the design of a portable, high intrinsic efficiency, and accurate neutron rem meter whose energy-dependent response is electronically adjusted to a chosen neutron dose equivalent standard. The instrument may be classified as a moderating type neutron spectrometer, based on an adaptation to the classical Bonner sphere and position sensitive long counter, which, simultaneously counts thermalized neutrons by high thermal efficiency solid state neutron detectors. The use of multiple detectors and moderator arranged along an axis of symmetry (e.g., long axis of a cylinder) with known neutron-slowing properties allows for the construction of a linear combination of responses that approximate the ambient neutron dose equivalent. Variations on the detector configuration are investigated via Monte Carlo N-Particle simulations to minimize the total instrument mass while maintaining acceptable response accuracy—a dose error less than 15% for bare {sup 252}Cf, bare AmBe, an epi-thermal and mixed monoenergetic sources is found at less than 4.5 kg moderator mass in all studied cases. A comparison of the energy dependent dose equivalent response and resultant energy dependent dose equivalent error of the present dosimeter to commercially-available portable rem meters and the prior art are presented. Finally, the present design is assessed by comparison of the simulated output resulting from applications of several known neutron sources and dose rates.

Decreased sleep spindle density in patients with idiopathic REM sleep behavior disorder and patients with Parkinson’s disease

DEFF Research Database (Denmark)

Christensen, Julie Anja Engelhard; Kempfner, Jacob; Zoetmulder, Marielle

2014-01-01

ObjectiveTo determine whether sleep spindles (SS) are potentially a biomarker for Parkinson’s disease (PD). MethodsFifteen PD patients with REM sleep behavior disorder (PD+RBD), 15 PD patients without RBD (PD−RBD), 15 idiopathic RBD (iRBD) patients and 15 age-matched controls underwent...... polysomnography (PSG). SS were scored in an extract of data from control subjects. An automatic SS detector using a Matching Pursuit (MP) algorithm and a Support Vector Machine (SVM) was developed and applied to the PSG recordings. The SS densities in N1, N2, N3, all NREM combined and REM sleep were obtained...

The REM route to more syncrude

Energy Technology Data Exchange (ETDEWEB)

Law, C

1980-09-03

Norcen will become the first industry major to support a feasibility study of REM, an acronym for Resource and Energy Management. The prospective joint project involving Norcen Energy Resources and the Federal Department of Energy, Mines and Resources will consider coal utilization in the recovery and upgrading of heavy crude from Western Canadian deposits. The project will facilitate smaller projects at Cold Lake and will also be relevant to large scale plants, whether in-situ or surface-mined tar sands or heavy oil applications. The innovation: gasifying coal (rather than burning natural gas or liquids) to raise steam and electric power in a synergistic combined cycle system, and electrolyzing water to win essential hydrogen and oxygen for the upgrading process. The bonuses: the generation of hydrogen and oxygen without the consumption of premium light hydrocarbons in a clean, energy efficient process. The objective: higher yield of light oil at lower unit cost, better sulfur control and modular design for small or large scale plants.

Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

Science.gov (United States)

Dijk, D. J.

1999-01-01

In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

REM sleep behavior disorder in Parkinson disease: association with abnormal ocular motor findings.

Science.gov (United States)

Kim, Young Eun; Yang, Hui June; Yun, Ji Young; Kim, Han-Joon; Lee, Jee-Young; Jeon, Beom S

2014-04-01

The anatomical substrates associated with generalized muscle atonia during REM sleep are located on the pontine tegmentum and medial medulla oblongata. We examined whether patients with REM sleep behavior disorder (RBD) have abnormal ocular movements suggesting brainstem or cerebellar dysfunction in Parkinson's disease (PD). Cross-sectional survey for the existence of RBD and abnormal ocular movements. Ocular movements were examined by video-oculography (VOG). A total of 202 patients were included in this study. One hundred and sixteen (57.4%) of the 202 patients have clinically probable RBD, and 28 (24.1%) of the 116 with clinically probable RBD patients had abnormal VOG findings suggesting brainstem or cerebellar dysfunction; whereas 86 of the 202 patients did not have clinically probable RBD, and only 7 (8.1%) of the 86 patients had abnormal VOG findings suggesting brainstem or cerebellar dysfunction (P=0.001). This study suggests that the presence of RBD is associated with more severe or extensive brainstem pathology or different distribution of pathology in PD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neutron measurement in 12,13C+ 27Al system using CR-39 detectors and neutron rem meter

International Nuclear Information System (INIS)

Sahoo, G.S.; Tripathy, S.P.; Shanbhag, A.A.; Sunil, C.; Joshi, D.S.; Sarkar, P.K.

2011-01-01

In this work, neutron measurements carried out for the interaction of 60 and 67.5 MeV 12 C, 57.3 and 65 MeV 13 C ions with thick aluminium target by using CR-39 detectors and neutron rem meter is reported. Both the detector systems were irradiated at different angles viz. 0 deg, 30 deg, 60 deg, 90 deg with respect to the beam direction. The normalized track density measurements (tracks/cm 2 /projectile at 1m) in CR-39 detectors were correlated with the normalized dose equivalent values (μSv/projectile at 1m) obtained using the neutron rem meter. The track density was found to be more in case of 13 C than 12 C. However in all the cases, the track density per incident projectile was found to decrease as the angle with respect to beam direction increases, indicating non-isotropic nature of neutron emission. The ratio between measured dose equivalent in rem meter to the measured track densities in CR-39 detectors was found to be 2.8±0.2, which remains constant irrespective of the change in angle from beam direction as well as neutron spectrum, indicating a flat dose response of CR-39 detectors. (author)

Design and development of wide energy neutron REM equivalent spectrometer-dosimeters based on polycarbonates and Cr-39

International Nuclear Information System (INIS)

Faermann, S.

1985-03-01

This work describes a system composed of a Rem response personnel neutron dosemeter, based on boron radiators and a polycarbonate track detector, for monitoring dose equivalents in the energy range 1 eV to 14 MeV, an electrochemical etching system for revealing damage sites in solid state track etch detectors, a reader for magnifying the etched pits and a microprocessor for evaluating the dose equivalents and their uncertainties. The performance and directional dependence of the dosemeter when exposed to monoenergetic and polyenergetic neutron fields in the epithermal and fast energy regions are discussed. Saturation effects in polycarbonate foils are presented and a comparison is made between the response of polycarbonate and CR-39 foils, used as passive detectors in the dosemeter. A new passive miniature fast neutron spectrometer-dosimeter is also described. The device is based on the detection of proton tracks by electrochemical etching of CR-39 foils covered with thin polyethylene layers of different thicknesses. By means of this device it is possible to assess the fast neutron energy spectrum in 10 energy intervals in the energy range 0.5-15 MeV. Dose equivalents can be determined in the dose equivalent range 20 mRem to 8 Rem, approximately (author)

Winds Measured by the Rover Environmental Monitoring Station (REMS) During the Mars Science Laboratory (MSL) Rover's Bagnold Dunes Campaign and Comparison with Numerical Modeling Using MarsWRF

Science.gov (United States)

Newman, Claire E.; Gomez-Elvira, Javier; Marin, Mercedes; Navarro, Sara; Torres, Josefina; Richardson, Mark I.; Battalio, J. Michael; Guzewich, Scott D.; Sullivan, Robert; de la Torre, Manuel;

Chronic REM-sleep deprivation of rats elevates metabolic rate and increases UCP1 gene expression in brown adipose tissue.

Science.gov (United States)

Koban, Michael; Swinson, Kevin L

2005-07-01

A cluster of unique pathologies progressively develops during chronic total- or rapid eye movement-sleep deprivation (REM-SD) of rats. Two prominent and readily observed symptoms are hyperphagia and decline in body weight. For body weight to be lost despite a severalfold increase in food consumption suggests that SD elevates metabolism as the subject enters a state of negative energy balance. To test the hypothesis that mediation of this hypermetabolism involves increased gene expression of uncoupling protein-1 (UCP1), which dissipates the thermodynamic energy of the mitochondrial proton-motive force as heat instead of ATP formation in brown adipose tissue (BAT), we 1) established the time course and magnitude of change in metabolism by measuring oxygen consumption, 2) estimated change in UCP1 gene expression in BAT by RT-PCR and Western blot, and 3) assayed serum leptin because of its role in regulating energy balance and food intake. REM-SD of male Sprague-Dawley rats was enforced for 20 days with the platform (flowerpot) method, wherein muscle atonia during REM sleep causes contact with surrounding water and awakens it. By day 20, rats more than doubled food consumption while losing approximately 11% of body weight; metabolism rose to 166% of baseline with substantial increases in UCP1 mRNA and immunoreactive UCP1 over controls; serum leptin decreased and remained suppressed. The decline in leptin is consistent with the hyperphagic response, and we conclude that one of the mediators of elevated metabolism during prolonged REM-SD is increased gene expression of UCP1 in BAT.

The effect of heat treatment on recrystallized microstructure, precipitation and ductility of hot-rolled Fe–Cr–Al–REM ferritic stainless steel sheets

International Nuclear Information System (INIS)

Qu, H.P.; Lang, Y.P.; Yao, C.F.; Chen, H.T.; Yang, C.Q.

2013-01-01

This study presents research works about the effects of heat treatment on recrystallized equiaxed grain size, precipitation, room temperature (RT) toughness and ductile to brittle transition temperature (DBTT) of Fe–Cr–Al–REM ferritic stainless steel (FSS) hot-rolled sheet. Results showed that the recrystallization of hot-rolled Fe–Cr–Al–REM FSS sheet could be completed after annealing treatment at 750 °C for 15 min with the equiaxed grain diameter of approximately 50 μm. Inappropriate annealing treatment would inevitably leads to the unexpected grain coarsening. On the other hand, a great deal of needle-like or spot-like fine aluminum–lanthanum compound Al 11 La 3 precipitates were observed in the ferrite matrix after 1 h aging treatment at 750 °C. The microstructure observation results associated with the impact test definitely illustrated that the Al 11 La 3 precipitates was the reason for the brittle crack in the as-casted ingot and as-forged slab. The real DBTT of the annealed Fe–Cr–Al–REM FSS sheet with average grain size of about 50 μm was −4 °C. Meanwhile, the DBTT of the hot-rolled Fe–Cr–Al–REM stainless steel sheet was evidently increased as the recrystallized grain size increased.

The effect of heat treatment on recrystallized microstructure, precipitation and ductility of hot-rolled Fe-Cr-Al-REM ferritic stainless steel sheets

Energy Technology Data Exchange (ETDEWEB)

Qu, H.P., E-mail: quhuapeng0926@163.com [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Lang, Y.P. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Yao, C.F. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Zhuozhou Works, Central Iron and Steel Research Institute (CISRI), 2 HuoJuNan Road, Zhuozhou 072750, Hebei (China); Chen, H.T.; Yang, C.Q. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China)

2013-02-01

This study presents research works about the effects of heat treatment on recrystallized equiaxed grain size, precipitation, room temperature (RT) toughness and ductile to brittle transition temperature (DBTT) of Fe-Cr-Al-REM ferritic stainless steel (FSS) hot-rolled sheet. Results showed that the recrystallization of hot-rolled Fe-Cr-Al-REM FSS sheet could be completed after annealing treatment at 750 Degree-Sign C for 15 min with the equiaxed grain diameter of approximately 50 {mu}m. Inappropriate annealing treatment would inevitably leads to the unexpected grain coarsening. On the other hand, a great deal of needle-like or spot-like fine aluminum-lanthanum compound Al{sub 11}La{sub 3} precipitates were observed in the ferrite matrix after 1 h aging treatment at 750 Degree-Sign C. The microstructure observation results associated with the impact test definitely illustrated that the Al{sub 11}La{sub 3} precipitates was the reason for the brittle crack in the as-casted ingot and as-forged slab. The real DBTT of the annealed Fe-Cr-Al-REM FSS sheet with average grain size of about 50 {mu}m was -4 Degree-Sign C. Meanwhile, the DBTT of the hot-rolled Fe-Cr-Al-REM stainless steel sheet was evidently increased as the recrystallized grain size increased.

Alexithymia associated with nightmare distress in idiopathic REM sleep behavior disorder.

Science.gov (United States)

Godin, Isabelle; Montplaisir, Jaques; Gagnon, Jean-François; Nielsen, Tore

2013-12-01

Idiopathic REM sleep behavior disorder (iRBD) is characterized by atypical REM sleep motor activity, vivid dreams and nightmares, and dream-enacting behaviors that can result in injuries to the patient and bed partner. It is also a known predictor of Parkinson disease (PD). Alexithymia has been associated with disturbances in sleep and dreaming (e.g., nightmares) and is a non-motor symptom of PD. We assessed alexithymia and disturbed dreaming in iRBD patients with the aim of determining if these two factors are elevated and interrelated among this population. Questionnaire study of clinically diagnosed patients. Clinical sleep disorders center. Thirty-two iRBD patients and 30 healthy age- and sex-matched control participants. Participants completed the 20-item Toronto Alexithymia Scale (TAS-20), the Dream Questionnaire, and the Beck Depression Inventory. iRBD patients obtained higher TAS-20 total scores (62.16 ± 13.90) than did controls (52.84 ± 7.62; F 1,59 = 10.44, P sleep behavior disorder patients, and especially a difficulty in identifying feelings, parallels evidence of dysautonomia in this population. The higher incidence of distressing nightmares and the association of nightmares with alexithymia further extend similar findings for both clinical and non-clinical samples and suggest that an affect regulation disturbance may be common to the two sets of symptoms.

Short-Term Total Sleep-Deprivation Impairs Contextual Fear Memory, and Contextual Fear-Conditioning Reduces REM Sleep in Moderately Anxious Swiss Mice

Directory of Open Access Journals (Sweden)

Munazah F. Qureshi

2017-11-01

Full Text Available The conditioning tasks have been widely used to model fear and anxiety and to study their association with sleep. Many reports suggest that sleep plays a vital role in the consolidation of fear memory. Studies have also demonstrated that fear-conditioning influences sleep differently in mice strains having a low or high anxiety level. It is, therefore, necessary to know, how sleep influences fear-conditioning and how fear-conditioning induces changes in sleep architecture in moderate anxious strains. We have used Swiss mice, a moderate anxious strain, to study the effects of: (i sleep deprivation on contextual fear conditioned memory, and also (ii contextual fear conditioning on sleep architecture. Animals were divided into three groups: (a non-sleep deprived (NSD; (b stress control (SC; and (c sleep-deprived (SD groups. The SD animals were SD for 5 h soon after training. We found that the NSD and SC animals showed 60.57% and 58.12% freezing on the testing day, while SD animals showed significantly less freezing (17.13% only; p < 0.001 on the testing day. Further, we observed that contextual fear-conditioning did not alter the total amount of wakefulness and non-rapid eye movement (NREM sleep. REM sleep, however, significantly decreased in NSD and SC animals on the training and testing days. Interestingly, REM sleep did not decrease in the SD animals on the testing day. Our results suggest that short-term sleep deprivation impairs fear memory in moderate anxious mice. It also suggests that NREM sleep, but not REM sleep, may have an obligatory role in memory consolidation.

Predictable Internal Brain Dynamics in EEG and Its Relation to Conscious States

Directory of Open Access Journals (Sweden)

Jaewook eYoo

2014-06-01

Full Text Available Consciousness is a complex and multi-faceted phenomenon defying scientific explanation. Part of the reason why this is the case is due to its subjective nature. In our previous computational experiments, to avoid such a subjective trap, we took a strategy to investigate objective necessary conditions of consciousness. Our basic hypothesis was that predictive internal dynamics serves as such a condition. This is in line with theories of consciousness that treat retention (memory, protention (anticipation, and primary impression as the tripartite temporal structure of consciousness. To test our hypothesis, we analyzed publicly available sleep and awake electroencephalogram (EEG data. Our results show that EEG signals from awake or rapid eye movement (REM sleep states have more predictable dynamics compared to those from slow-wave sleep (SWS. Since awakeness and REM sleep are associated with conscious states and SWS with unconscious or less consciousness states, these results support our hypothesis. The results suggest an intricate relationship among prediction, consciousness, and time, with potential applications to time perception and neurorobotics.

Sleep-related declarative memory consolidation and verbal replay during sleep talking in patients with REM sleep behavior disorder.

Directory of Open Access Journals (Sweden)

Ginevra Uguccioni

Full Text Available OBJECTIVE: To determine if sleep talkers with REM sleep behavior disorder (RBD would utter during REM sleep sentences learned before sleep, and to evaluate their verbal memory consolidation during sleep. METHODS: Eighteen patients with RBD and 10 controls performed two verbal memory tasks (16 words from the Free and Cued Selective Reminding Test and a 220-263 word long modified Story Recall Test in the evening, followed by nocturnal video-polysomnography and morning recall (night-time consolidation. In 9 patients with RBD, daytime consolidation (morning learning/recall, evening recall was also evaluated with the modified Story Recall Test in a cross-over order. Two RBD patients with dementia were studied separately. Sleep talking was recorded using video-polysomnography, and the utterances were compared to the studied texts by two external judges. RESULTS: Sleep-related verbal memory consolidation was maintained in patients with RBD (+24±36% words as in controls (+9±18%, p=0.3. The two demented patients with RBD also exhibited excellent nighttime consolidation. The post-sleep performance was unrelated to the sleep measures (including continuity, stages, fragmentation and apnea-hypopnea index. Daytime consolidation (-9±19% was worse than night-time consolidation (+29±45%, p=0.03 in the subgroup of 9 patients with RBD. Eleven patients with RBD spoke during REM sleep and pronounced a median of 20 words, which represented 0.0003% of sleep with spoken language. A single patient uttered a sentence that was judged to be semantically (but not literally related to the text learned before sleep. CONCLUSION: Verbal declarative memory normally consolidates during sleep in patients with RBD. The incorporation of learned material within REM sleep-associated sleep talking in one patient (unbeknownst to himself at the semantic level suggests a replay at a highly cognitive creative level.

Sleep transitions in hypocretin-deficient narcolepsy.

Science.gov (United States)

Sorensen, Gertrud Laura; Knudsen, Stine; Jennum, Poul

2013-08-01

Narcolepsy is characterized by instability of sleep-wake, tonus, and rapid eye movement (REM) sleep regulation. It is associated with severe hypothalamic hypocretin deficiency, especially in patients with cataplexy (loss of tonus). As the hypocretin neurons coordinate and stabilize the brain's sleep-wake pattern, tonus, and REM flip-flop neuronal centers in animal models, we set out to determine whether hypocretin deficiency and/or cataplexy predicts the unstable sleep-wake and REM sleep pattern of the human phenotype. We measured the frequency of transitions in patients with narcolepsy between sleep-wake states and to/from REM and NREM sleep stages. Patients were subdivided by the presence of +/- cataplexy and +/- hypocretin-1 deficiency. Sleep laboratory studies conducted from 2001-2011. In total 63 narcolepsy patients were included in the study. Cataplexy was present in 43 of 63 patients and hypocretin-1 deficiency was present in 37 of 57 patients. Hypocretin-deficient patients with narcolepsy had a significantly higher frequency of sleep-wake transitions (P = 0.014) and of transitions to/from REM sleep (P = 0.044) than patients with normal levels of hypocretin-1. Patients with cataplexy had a significantly higher frequency of sleep-wake transitions (P = 0.002) than those without cataplexy. A multivariate analysis showed that transitions to/from REM sleep were predicted mainly by hypocretin-1 deficiency (P = 0.011), whereas sleep-wake transitions were predicted mainly by cataplexy (P = 0.001). In human narcolepsy, hypocretin deficiency and cataplexy are both associated with signs of destabilized sleep-wake and REM sleep control, indicating that the disorder may serve as a human model for the sleep-wake and REM sleep flip-flop switches.

Modelling bankruptcy prediction models in Slovak companies

Directory of Open Access Journals (Sweden)

Kovacova Maria

2017-01-01

Full Text Available An intensive research from academics and practitioners has been provided regarding models for bankruptcy prediction and credit risk management. In spite of numerous researches focusing on forecasting bankruptcy using traditional statistics techniques (e.g. discriminant analysis and logistic regression and early artificial intelligence models (e.g. artificial neural networks, there is a trend for transition to machine learning models (support vector machines, bagging, boosting, and random forest to predict bankruptcy one year prior to the event. Comparing the performance of this with unconventional approach with results obtained by discriminant analysis, logistic regression, and neural networks application, it has been found that bagging, boosting, and random forest models outperform the others techniques, and that all prediction accuracy in the testing sample improves when the additional variables are included. On the other side the prediction accuracy of old and well known bankruptcy prediction models is quiet high. Therefore, we aim to analyse these in some way old models on the dataset of Slovak companies to validate their prediction ability in specific conditions. Furthermore, these models will be modelled according to new trends by calculating the influence of elimination of selected variables on the overall prediction ability of these models.

Rem Koolhaas y la nueva Babel. De la torre metropolitana al monumento al vacío

Directory of Open Access Journals (Sweden)

José Antonio Tallón

2015-05-01

Full Text Available Un primer acercamiento a las reflexiones de Rem Koolhaas en torno a la tipología de torre introduce al rascacielos neoyorquino como la alegoría del “automonumen­to”: una construcción en esencia destinada a reafirmar su sola presencia y que se distingue del resto por medio de su estatura, que la monumentaliza. La torre de Babel, símbolo inquebrantable de la leyenda de la construcción en altura, escenifi­ca una historia de construcción y destrucción que está vinculada ineludiblemente al pensamiento crítico de Rem Koolhaas en torno a la torre como tipología desa­creditada. Un recorrido por las distintas “Babel” que Rem Koolhaas cataloga en el glosario de términos incluido en el texto SMLXL construye un discurso en torno a la destrucción de la torre bíblica y la construcción de la nueva Babel koolhaasiana que inicia su recorrido con el rascacielos para acabar reclamando un nuevo estado de monumentalidad: la ausencia en su estado más puro representado por el muro, el máximo ejemplo de ausencia como la forma más elevada de presencia monu­mental. Una mirada crítica que comienza con la torre metropolitana como la nueva Babel para finalizar con el muro como el monumento al vacío

Altered functional connectivity in lesional peduncular hallucinosis with REM sleep behavior disorder.

Science.gov (United States)

Geddes, Maiya R; Tie, Yanmei; Gabrieli, John D E; McGinnis, Scott M; Golby, Alexandra J; Whitfield-Gabrieli, Susan

2016-01-01

Brainstem lesions causing peduncular hallucinosis (PH) produce vivid visual hallucinations occasionally accompanied by sleep disorders. Overlapping brainstem regions modulate visual pathways and REM sleep functions via gating of thalamocortical networks. A 66-year-old man with paroxysmal atrial fibrillation developed abrupt-onset complex visual hallucinations with preserved insight and violent dream enactment behavior. Brain MRI showed restricted diffusion in the left rostrodorsal pons suggestive of an acute ischemic stroke. REM sleep behavior disorder (RBD) was diagnosed on polysomnography. We investigated the integrity of ponto-geniculate-occipital circuits with seed-based resting-state functional connectivity MRI (rs-fcMRI) in this patient compared to 46 controls. Rs-fcMRI revealed significantly reduced functional connectivity between the lesion and lateral geniculate nuclei (LGN), and between LGN and visual association cortex compared to controls. Conversely, functional connectivity between brainstem and visual association cortex, and between visual association cortex and prefrontal cortex (PFC) was significantly increased in the patient. Focal damage to the rostrodorsal pons is sufficient to cause RBD and PH in humans, suggesting an overlapping mechanism in both syndromes. This lesion produced a pattern of altered functional connectivity consistent with disrupted visual cortex connectivity via de-afferentation of thalamocortical pathways. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Effects of REM and Ba Additions on the Characteristics of the Third Generation Duplex Stainless Steel

International Nuclear Information System (INIS)

Park, Yong Soo; Kim, Soon Tae

2006-01-01

The third generation super duplex stainless steel having excellent corrosion resistance, embrittlement resistance, castability, weldability and hot workability has been developed. REM and Ba added to the alloy, with larger atomic radius than those of Cr, Mo and W, seem to fill vacancies inside the matrix and around the grain boundaries, retarding formation of brittle σ and χ phases. In addition, fine oxides/ oxy-sulfides of REM and Ba (1∼3 μm in diameter) seem to enhance the retardation effects. The alloys have also shown higher strength and ductility resulting from phase and grain refinements caused by those oxides and oxy-sulfides. Accordingly it is judged that the core technology can provide the method for remarkably suppressing formation of intermetallic phases by adding new alloy elements, and improving a applied to sea water and flue gas desulfurization facility

The sleeping brain in Parkinson's disease: A focus on REM sleep behaviour disorder and related parasomnias for practicing neurologists.

Science.gov (United States)

Bhidayasiri, Roongroj; Sringean, Jirada; Rattanachaisit, Watchara; Truong, Daniel D

2017-03-15

Sleep disorders are identified as common non-motor symptoms of Parkinson's disease (PD) and recently this recognition has been expanded to include parasomnias, encompassing not only REM sleep behaviour disorder (RBD), but also other non-REM forms. RBD, a prototypical parasomnia in PD, exists even in the prodromal stage of the disease, and is characterized by the presence of dream enactment behaviours occurring alongside a loss of normal skeletal muscle atonia during REM sleep. In contrast, non-REM parasomnias are more frequently observed in the late stage PD. However, the development of these disorders often overlaps and it is not uncommon for PD patients to meet the criteria for more than one type of parasomnias, thus making a clinical distinction challenging for practicing neurologists who are not sleep specialists. Indeed, clinical recognition of the predominant form of parasomnia does not just depend on video-polysomnography, but also on an individual physician's clinical acumen in delineating pertinent clinical history to determine the most likely diagnosis and proceed accordingly. In this review article, we highlight the various forms of parasomnias that have been reported in PD, including, but not limited to, RBD, with a focus on clinical symptomatology and implications for clinical practice. In addition, we review the differences in PD-related parasomnias compared to those seen in general populations. With advances in sleep research and better technology for ambulatory home monitoring, it is likely that many unanswered questions on PD-related parasomnias will soon be resolved resulting in better management of this nocturnal challenge in PD. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalencia de los factores que afectan el sueño REM y el brote de ondas lentas en los estudios con CPAP en apnea obstructiva del sueño

OpenAIRE

Osuna S, Edgar; Siddiqui, Fouzia; Vanegas, Marco A; Walters, Arthur S; Chokroverty, Sudhansu

2008-01-01

Background. In patients with obstructive sleep apnea syndrome (OSAS) treatment with CPAP results in an increase of REM sleep and slow wave sleep, but there is limited information about the prevalence of REM rebound in patients with OSAS and possible factors related to the rebound. Objective. REM rebound (RR) and slow wave sleep rebound (SWSR) has been described as a frequent phenomenon that occurs during CPAP titration, but the quantity that qualify for RR has not been mentioned in literature...

Modulation of Sleep Homeostasis by Corticotropin Releasing Hormone in REM Sleep-Deprived Rats

Directory of Open Access Journals (Sweden)

Ricardo Borges Machado

2010-01-01

Full Text Available Studies have shown that sleep recovery following different protocols of forced waking varies according to the level of stress inherent to each method. Sleep deprivation activates the hypothalamic-pituitary-adrenal axis and increased corticotropin-releasing hormone (CRH impairs sleep. The purpose of the present study was to evaluate how manipulations of the CRH system during the sleep deprivation period interferes with subsequent sleep rebound. Throughout 96 hours of sleep deprivation, separate groups of rats were treated i.c.v. with vehicle, CRH or with alphahelical CRH9−41, a CRH receptor blocker, twice/day, at 07:00 h and 19:00 h. Both treatments impaired sleep homeostasis, especially in regards to length of rapid eye movement sleep (REM and theta/delta ratio and induced a later decrease in NREM and REM sleep and increased waking bouts. These changes suggest that activation of the CRH system impact negatively on the homeostatic sleep response to prolonged forced waking. These results indicate that indeed, activation of the HPA axis—at least at the hypothalamic level—is capable to reduce the sleep rebound induced by sleep deprivation.

In-Home Sleep Recordings in Military Veterans With Posttraumatic Stress Disorder Reveal Less REM and Deep Sleep <1 Hz.

Science.gov (United States)

Onton, Julie A; Matthews, Scott C; Kang, Dae Y; Coleman, Todd P

2018-01-01

Veterans with posttraumatic stress disorder (PTSD) often report suboptimal sleep quality, often described as lack of restfulness for unknown reasons. These experiences are sometimes difficult to objectively quantify in sleep lab assessments. Here, we used a streamlined sleep assessment tool to record in-home 2-channel electroencephalogram (EEG) with concurrent collection of electrodermal activity (EDA) and acceleration. Data from a single forehead channel were transformed into a whole-night spectrogram, and sleep stages were classified using a fully automated algorithm. For this study, 71 control subjects and 60 military-related PTSD subjects were analyzed for percentage of time spent in Light, Hi Deep (1-3 Hz), Lo Deep (spend a smaller percentage of the night in REM ( p spending a larger percentage of the night in Hi Deep ( p < 0.0001) sleep. The percentage of combined Hi+Lo Deep sleep did not differ between groups. All sleepers usually showed EDA peaks during Lo, but not Hi, Deep sleep; however, PTSD sleepers were more likely to lack EDA peaks altogether, which usually coincided with a lack of Lo Deep sleep. Linear regressions with all subjects showed that a decreased percentage of REM sleep in PTSD sleepers was accounted for by age, prazosin, SSRIs and SNRIs ( p < 0.02), while decreased Lo Deep and increased Hi Deep in the PTSD group could not be accounted for by any factor in this study ( p < 0.005). Linear regression models with only the PTSD group showed that decreased REM correlated with self-reported depression, as measured with the Depression, Anxiety, and Stress Scales (DASS; p < 0.00001). DASS anxiety was associated with increased REM time ( p < 0.0001). This study shows altered sleep patterns in sleepers with PTSD that can be partially accounted for by age and medication use; however, differences in deep sleep related to PTSD could not be linked to any known factor. With several medications [prazosin, selective serotonin reuptake inhibitors (SSRIs

REMI and ROUSE: Quantitative Models for Long-Term and Short-Term Priming in Perceptual Identification

NARCIS (Netherlands)

E.J. Wagenmakers (Eric-Jan); R. Zeelenberg (René); D.E. Huber (David); J.G.W. Raaijmakers (Jeroen)

2003-01-01

textabstractThe REM model originally developed for recognition memory (Shiffrin & Steyvers, 1997) has recently been extended to implicit memory phenomena observed during threshold identification of words. We discuss two REM models based on Bayesian principles: a model for long-term priming (REMI;

External radiation survey and dose predictions for Rongelap, Utirik, Rongerik, Ailuk, and Wotje Atolls

International Nuclear Information System (INIS)

Greenhouse, N.A.; Miltenberger, R.P.

1977-01-01

External radiation measurements were made at several atolls in the northern Marshall Islands, which are known or suspected to have been the recipients of tropospheric fallout during the Pacific Testing Programs. Sufficient data were available to ascertain realistic dose predictions for the inhabitants of Rongelap and Utirik Atolls where the 30 year integral doses from external sources exclusive of background radiation were 0.65 and 0.06 rem respectively. These estimates are based on realistic life-style models based on observations of each atoll community. Ailuk and Wotje Atolls were found to be represenatives of regional background radiation levels

Predictive modeling of complications.

Science.gov (United States)

Osorio, Joseph A; Scheer, Justin K; Ames, Christopher P

2016-09-01

Predictive analytic algorithms are designed to identify patterns in the data that allow for accurate predictions without the need for a hypothesis. Therefore, predictive modeling can provide detailed and patient-specific information that can be readily applied when discussing the risks of surgery with a patient. There are few studies using predictive modeling techniques in the adult spine surgery literature. These types of studies represent the beginning of the use of predictive analytics in spine surgery outcomes. We will discuss the advancements in the field of spine surgery with respect to predictive analytics, the controversies surrounding the technique, and the future directions.

Rivastigmine for refractory REM behavior disorder in mild cognitive impairment.

Science.gov (United States)

Brunetti, Valerio; Losurdo, Anna; Testani, Elisa; Lapenta, Leonardo; Mariotti, Paolo; Marra, Camillo; Rossini, Paolo Maria; Della Marca, Giacomo

2014-03-01

Mild Cognitive Impairment (MCI) and REM Behavior Disorder (RBD) are both associated with a degeneration of ponto-medullary cholinergic pathways. We conducted a placebo-controlled, cross-over pilot trial of Rivastigmine (RVT) in 25 consecutive patients with MCI, who presented RBD refractory to conventional first-line treatments (melatonin up to 5 mg/day and clonazepam up to 2 mg/day). RVT treatment was followed by a significant reduction of RBD episodes when compared with placebo. Our data suggest that, in MCI patients with RBD resistant to conventional therapies (muscle relaxants benzodiazepines or melatonin,) treatment with RVT may induce a reduction in the frequency of RBD episodes compared to placebo.

Identification of high-risk areas for harbour porpoise Phocoena phocoena bycatch using remote electronic monitoring and satellite telemetry data

DEFF Research Database (Denmark)

Kindt-Larsen, Lotte; Berg, Casper Willestofte; Tougaard, J.

2016-01-01

grounds, quantify fishing effort and document harbour porpoise bycatch. Movement data from 66 harbour porpoises equipped with satellite transmitters from 1997 to 2012 were used to model population density. A simple model was constructed to investigate the relationship between the response (number...... telemetry or REM data allow for identification of areas of potential high and low bycatch risk, and better predictions are obtained when combining the 2 sources of data. The final model can thus be used as a tool to identify areas of bycatch risk...... and lower risk of porpoise bycatch. From May 2010 to April 2011, 4 commercial gillnet vessels were equipped with remote electronic monitoring (REM) systems. The REM system recorded time, GPS position and closed-circuit television (CCTV) footage of all gillnet hauls. REM data were used to identify fishing...

Pas de remède miracle Parvenir à une couverture santé universelle ...

International Development Research Centre (IDRC) Digital Library (Canada)

26 oct. 2012 ... Pas de remède miracle Parvenir à une couverture santé universelle grâce à des systèmes de santé équitables ... Le Nigeria, qui compte parmi les pays qui affichent les taux les plus élevés de mortalité des mères, des enfants et des nouveau-nés, a fait des soins de santé primaires sa plus grande priorité.

Candidate Prediction Models and Methods

DEFF Research Database (Denmark)

Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik

2005-01-01

This document lists candidate prediction models for Work Package 3 (WP3) of the PSO-project called ``Intelligent wind power prediction systems'' (FU4101). The main focus is on the models transforming numerical weather predictions into predictions of power production. The document also outlines...... the possibilities w.r.t. different numerical weather predictions actually available to the project....

Did Immanuel Kant have dementia with Lewy bodies and REM behavior disorder?

Science.gov (United States)

Miranda, Marcelo; Slachevsky, Andrea; Garcia-Borreguero, Diego

2010-06-01

Immanuel Kant, one of the most brilliant minds of the XVIII century and of western philosophy, suffered from dementia in his late years. Based on the analysis of testimonies of his close friends, in this report we describe his neurological disorder which, after 8years of evolution, led to his death. His cognitive decline was strongly associated with a parasomnia compatible with a severe rapid eye movement (REM) behavior disorder (RBD) and dementia with Lewy bodies. Copyright 2010 Elsevier B.V. All rights reserved.

Sleep Transitions in Hypocretin-Deficient Narcolepsy

DEFF Research Database (Denmark)

Sorensen, Gertrud Laura; Knudsen, Stine; Jennum, Poul

2013-01-01

Narcolepsy is characterized by instability of sleep-wake, tonus, and rapid eye movement (REM) sleep regulation. It is associated with severe hypothalamic hypocretin deficiency, especially in patients with cataplexy (loss of tonus). As the hypocretin neurons coordinate and stabilize the brain......'s sleep-wake pattern, tonus, and REM flip-flop neuronal centers in animal models, we set out to determine whether hypocretin deficiency and/or cataplexy predicts the unstable sleep-wake and REM sleep pattern of the human phenotype....

Wind power prediction models

Science.gov (United States)

Levy, R.; Mcginness, H.

1976-01-01

Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

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

Science.gov (United States)

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

2016-05-01

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

REM Sleep Behavior Disorder: Updated Review of the Core Features, the RBD-Neurodegenerative Disease Association, Evolving Concepts, Controversies, and Future Directions

Science.gov (United States)

Boeve, Bradley F.

2010-01-01

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia manifested by vivid, often frightening dreams associated with simple or complex motor behavior during REM sleep. Patients appear to “act out their dreams,” in which the exhibited behaviors mirror the content of the dreams, and the dream content often involves a chasing or attacking theme. The polysomnographic features of RBD include increased electromyographic tone +/- dream enactment behavior during REM sleep. Management with counseling and pharmacologic measures is usually straight-forward and effective. In this review, the terminology, clinical and polysomnographic features, demographic and epidemiologic features, diagnostic criteria, differential diagnosis, and management strategies are discussed. Recent data on the suspected pathophysiologic mechanisms of RBD are also reviewed. The literature and our institutional experience on RBD are next discussed, with an emphasis on the RBD-neurodegenerative disease association and particularly the RBD-synucleinopathy association. Several issues relating to evolving concepts, controversies, and future directions are then reviewed, with an emphasis on idiopathic RBD representing an early feature of a neurodegenerative disease and particularly an evolving synucleinopathy. Planning for future therapies that impact patients with idiopathic RBD is reviewed in detail. PMID:20146689

Inverse and Predictive Modeling

Energy Technology Data Exchange (ETDEWEB)

Syracuse, Ellen Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-27

The LANL Seismo-Acoustic team has a strong capability in developing data-driven models that accurately predict a variety of observations. These models range from the simple – one-dimensional models that are constrained by a single dataset and can be used for quick and efficient predictions – to the complex – multidimensional models that are constrained by several types of data and result in more accurate predictions. Team members typically build models of geophysical characteristics of Earth and source distributions at scales of 1 to 1000s of km, the techniques used are applicable for other types of physical characteristics at an even greater range of scales. The following cases provide a snapshot of some of the modeling work done by the Seismo- Acoustic team at LANL.

Archaeological predictive model set.

Science.gov (United States)

2015-03-01

This report is the documentation for Task 7 of the Statewide Archaeological Predictive Model Set. The goal of this project is to : develop a set of statewide predictive models to assist the planning of transportation projects. PennDOT is developing t...

A computerized glow curve analysis (GCA) method for WinREMS thermoluminescent dosimeter data using MATLAB

International Nuclear Information System (INIS)

Harvey, John A.; Rodrigues, Miesher L.; Kearfott, Kimberlee J.

2011-01-01

A computerized glow curve analysis (GCA) program for handling of thermoluminescence data originating from WinREMS is presented. The MATLAB program fits the glow peaks using the first-order kinetics model. Tested materials are LiF:Mg,Ti, CaF 2 :Dy, CaF 2 :Tm, CaF 2 :Mn, LiF:Mg,Cu,P, and CaSO 4 :Dy, with most having an average figure of merit (FOM) of 1.3% or less, with CaSO 4 :Dy 2.2% or less. Output is a list of fit parameters, peak areas, and graphs for each fit, evaluating each glow curve in 1.5 s or less. - Highlights: → Robust algorithm for performing thermoluminescent dosimeter glow curve analysis. → Written in MATLAB so readily implemented on variety of computers. → Usage of figure of merit demonstrated for six different materials.

Confidence scores for prediction models

DEFF Research Database (Denmark)

Gerds, Thomas Alexander; van de Wiel, MA

2011-01-01

In medical statistics, many alternative strategies are available for building a prediction model based on training data. Prediction models are routinely compared by means of their prediction performance in independent validation data. If only one data set is available for training and validation,...

Study of the response of a lithium yttrium borate scintillator based neutron rem counter by Monte Carlo radiation transport simulations

Science.gov (United States)

Sunil, C.; Tyagi, Mohit; Biju, K.; Shanbhag, A. A.; Bandyopadhyay, T.

2015-12-01

The scarcity and the high cost of 3He has spurred the use of various detectors for neutron monitoring. A new lithium yttrium borate scintillator developed in BARC has been studied for its use in a neutron rem counter. The scintillator is made of natural lithium and boron, and the yield of reaction products that will generate a signal in a real time detector has been studied by FLUKA Monte Carlo radiation transport code. A 2 cm lead introduced to enhance the gamma rejection shows no appreciable change in the shape of the fluence response or in the yield of reaction products. The fluence response when normalized at the average energy of an Am-Be neutron source shows promise of being used as rem counter.

Study of the response of a lithium yttrium borate scintillator based neutron rem counter by Monte Carlo radiation transport simulations

Energy Technology Data Exchange (ETDEWEB)

Sunil, C., E-mail: csunil11@gmail.com [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, Mohit [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Biju, K.; Shanbhag, A.A.; Bandyopadhyay, T. [Accelerator Radiation Safety Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2015-12-11

The scarcity and the high cost of {sup 3}He has spurred the use of various detectors for neutron monitoring. A new lithium yttrium borate scintillator developed in BARC has been studied for its use in a neutron rem counter. The scintillator is made of natural lithium and boron, and the yield of reaction products that will generate a signal in a real time detector has been studied by FLUKA Monte Carlo radiation transport code. A 2 cm lead introduced to enhance the gamma rejection shows no appreciable change in the shape of the fluence response or in the yield of reaction products. The fluence response when normalized at the average energy of an Am–Be neutron source shows promise of being used as rem counter.

Accurate and dynamic predictive model for better prediction in medicine and healthcare.

Science.gov (United States)

Alanazi, H O; Abdullah, A H; Qureshi, K N; Ismail, A S

2018-05-01

Information and communication technologies (ICTs) have changed the trend into new integrated operations and methods in all fields of life. The health sector has also adopted new technologies to improve the systems and provide better services to customers. Predictive models in health care are also influenced from new technologies to predict the different disease outcomes. However, still, existing predictive models have suffered from some limitations in terms of predictive outcomes performance. In order to improve predictive model performance, this paper proposed a predictive model by classifying the disease predictions into different categories. To achieve this model performance, this paper uses traumatic brain injury (TBI) datasets. TBI is one of the serious diseases worldwide and needs more attention due to its seriousness and serious impacts on human life. The proposed predictive model improves the predictive performance of TBI. The TBI data set is developed and approved by neurologists to set its features. The experiment results show that the proposed model has achieved significant results including accuracy, sensitivity, and specificity.

Virtual reality and consciousness inference in dreaming.

Science.gov (United States)

Hobson, J Allan; Hong, Charles C-H; Friston, Karl J

2014-01-01

This article explores the notion that the brain is genetically endowed with an innate virtual reality generator that - through experience-dependent plasticity - becomes a generative or predictive model of the world. This model, which is most clearly revealed in rapid eye movement (REM) sleep dreaming, may provide the theater for conscious experience. Functional neuroimaging evidence for brain activations that are time-locked to rapid eye movements (REMs) endorses the view that waking consciousness emerges from REM sleep - and dreaming lays the foundations for waking perception. In this view, the brain is equipped with a virtual model of the world that generates predictions of its sensations. This model is continually updated and entrained by sensory prediction errors in wakefulness to ensure veridical perception, but not in dreaming. In contrast, dreaming plays an essential role in maintaining and enhancing the capacity to model the world by minimizing model complexity and thereby maximizing both statistical and thermodynamic efficiency. This perspective suggests that consciousness corresponds to the embodied process of inference, realized through the generation of virtual realities (in both sleep and wakefulness). In short, our premise or hypothesis is that the waking brain engages with the world to predict the causes of sensations, while in sleep the brain's generative model is actively refined so that it generates more efficient predictions during waking. We review the evidence in support of this hypothesis - evidence that grounds consciousness in biophysical computations whose neuronal and neurochemical infrastructure has been disclosed by sleep research.

Experiences in troubleshooting of neutron rem monitor electronics and its subsequent calibration

International Nuclear Information System (INIS)

Maithani, Atul; Dash, Amit Kumar; Vijayasekaran, P.; Mathews, Geo; Ajoy, K.C.; Dhanasekaran, A.

2014-01-01

This paper deals with the troubleshooting of the signal processing and counting electronics of two no's of Neutron Rem monitors and its subsequent calibration. Electronics servicing with respect to detection of fault in the circuit board, replacement of faulty ICs, circuits (Analog and Digital) tracing and installation of new rechargeable battery pack was done. Electronic calibration using Test pulse generator was carried out for dose rate measurements, amplitude measurements and discriminator level setting. Serial communication settings were checked with both HyperTerminal and software for the monitors. Neutron Source calibration was also carried out for both the monitors. (author)

Man-rem audit - a tool for exposure ALARA at Madras Atomic Power Station

International Nuclear Information System (INIS)

Shivaramakrishnan, N.R.; Eswaran, G.; Gangamohan, M.; Sathish, A.V.; Ramasubramanian, K.V.; Gandhimathinathan, S.; Selvam, S.; Moolya, L.L.

2012-01-01

ALARA - acronym for As Low As Reasonably Achievable, which means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practical. ICRP has recommended ALARA to be implemented as a formal practice into the System of Dose Limitation, which contains three parts, 1) Justification of practice 2) Optimization 3) Dose Limits. As with the human endeavor, there is always room for improvement. Keeping this in mind, ALARA program is being practiced in our Nuclear Power Plants over the years. There has been a gradual reduction of collective dose in our Nuclear Power Plants due to successful implementation of the ALARA programs. This was possible due to the rigorous application of O and M experience, feedback and active participation of workforce towards ALARA. Furthermore, ALARA is an ongoing continual improvement programme towards collective dose reduction and has enough scope for improvement at any point of time. In order to substantiate the gains of ALARA programme and to improve it further, first time Mam-rem Audit was conducted at MAPS during the month of Sep-Oct 2010. This paper gives the brief outline about the method man-rem audit, its findings, corrective action implementation and the benefits derived from it. Man-rem audit similar to financial audit, serves as a tool for finding out grey areas where improvements is required so that station collective dose can be further optimized. It is one of the identified missions to achieve excellence in area of reducing station collective dose, unplanned exposures and RPP deviation. The scope of this audit is to bring further improvements in the reduction in station collective dose, create more awareness among the employees about ALARA principles and seek valuable suggestions for improvements. Audit team consisting of senior HP persons had one to one interaction with the individuals of the respective section in the field and tried to gather the information from the individual and

Colonic Oxidative and Mitochondrial Function in Parkinson’s Disease and Idiopathic REM Sleep Behavior Disorder

OpenAIRE

Morén, C.; González-Casacuberta, Í.; Navarro-Otano, J.; Juárez-Flores, D.; Vilas, D.; Garrabou, G.; Milisenda, J. C.; Pont-Sunyer, C.; Catalán-García, M.; Guitart-Mampel, M.; Tobías, E.; Cardellach, F.; Valldeoriola, F.; Iranzo, A.; Tolosa, E.

2017-01-01

Objective To determine potential mitochondrial and oxidative alterations in colon biopsies from idiopathic REM sleep behavior disorder (iRBD) and Parkinson's disease (PD) subjects. Methods Colonic biopsies from 7 iRBD subjects, 9 subjects with clinically diagnosed PD, and 9 healthy controls were homogenized in 5% w/v mannitol. Citrate synthase (CS) and complex I (CI) were analyzed spectrophotometrically. Oxidative damage was assessed either by lipid peroxidation, through malondialdehyde and h...

Elaboration of the Reciprocal-Engagement Model of Genetic Counseling Practice: a Qualitative Investigation of Goals and Strategies.

Science.gov (United States)

Redlinger-Grosse, Krista; Veach, Patricia McCarthy; LeRoy, Bonnie S; Zierhut, Heather

2017-12-01

As the genetic counseling field evolves, a comprehensive model of practice is critical. The Reciprocal-Engagement Model (REM) consists of 5 tenets and 17 goals. Lacking in the REM, however, are well-articulated counselor strategies and behaviors. The purpose of the present study was to further elaborate and provide supporting evidence for the REM by identifying and mapping genetic counseling strategies to the REM goals. A secondary, qualitative analysis was conducted on data from two prior studies: 1) focus group results of genetic counseling outcomes (Redlinger-Grosse et al., Journal of Genetic Counseling, 2015); and 2) genetic counselors' examples of successful and unsuccessful genetic counseling sessions (Geiser et al. 2009). Using directed content analysis, 337 unique strategies were extracted from focus group data. A Q-sort of the 337 strategies yielded 15 broader strategy domains that were then mapped to the successful and unsuccessful session examples. Differing prevalence of strategy domains identified in successful sessions versus the prevalence of domains identified as lacking in unsuccessful sessions provide further support for the REM goals. The most prevalent domains for successful sessions were Information Giving and Use Psychosocial Skills and Strategies; and for unsuccessful sessions, Information Giving and Establish Working Alliance. Identified strategies support the REM's reciprocal nature, especially with regard to addressing patients' informational and psychosocial needs. Patients' contributions to success (or lack thereof) of sessions was also noted, supporting a REM tenet that individual characteristics and the counselor-patient relationship are central to processes and outcomes. The elaborated REM could be used as a framework for certain graduate curricular objectives, and REM components could also inform process and outcomes research studies to document and further characterize genetic counselor strategies.

Multi-model analysis in hydrological prediction

Science.gov (United States)

Lanthier, M.; Arsenault, R.; Brissette, F.

2017-12-01

Hydrologic modelling, by nature, is a simplification of the real-world hydrologic system. Therefore ensemble hydrological predictions thus obtained do not present the full range of possible streamflow outcomes, thereby producing ensembles which demonstrate errors in variance such as under-dispersion. Past studies show that lumped models used in prediction mode can return satisfactory results, especially when there is not enough information available on the watershed to run a distributed model. But all lumped models greatly simplify the complex processes of the hydrologic cycle. To generate more spread in the hydrologic ensemble predictions, multi-model ensembles have been considered. In this study, the aim is to propose and analyse a method that gives an ensemble streamflow prediction that properly represents the forecast probabilities and reduced ensemble bias. To achieve this, three simple lumped models are used to generate an ensemble. These will also be combined using multi-model averaging techniques, which generally generate a more accurate hydrogram than the best of the individual models in simulation mode. This new predictive combined hydrogram is added to the ensemble, thus creating a large ensemble which may improve the variability while also improving the ensemble mean bias. The quality of the predictions is then assessed on different periods: 2 weeks, 1 month, 3 months and 6 months using a PIT Histogram of the percentiles of the real observation volumes with respect to the volumes of the ensemble members. Initially, the models were run using historical weather data to generate synthetic flows. This worked for individual models, but not for the multi-model and for the large ensemble. Consequently, by performing data assimilation at each prediction period and thus adjusting the initial states of the models, the PIT Histogram could be constructed using the observed flows while allowing the use of the multi-model predictions. The under-dispersion has been

Uncertainty Evaluation with Multi-Dimensional Model of LBLOCA in OPR1000 Plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Jieun; Oh, Deog Yeon; Seul, Kwang-Won; Lee, Jin Ho [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2016-10-15

KINS has used KINS-REM (KINS-Realistic Evaluation Methodology) which developed for Best- Estimate (BE) calculation and uncertainty quantification for regulatory audit. This methodology has been improved continuously by numerous studies, such as uncertainty parameters and uncertainty ranges. In this study, to evaluate the applicability of improved KINS-REM for OPR1000 plant, uncertainty evaluation with multi-dimensional model for confirming multi-dimensional phenomena was conducted with MARS-KS code. In this study, the uncertainty evaluation with multi- dimensional model of OPR1000 plant was conducted for confirming the applicability of improved KINS- REM The reactor vessel modeled using MULTID component of MARS-KS code, and total 29 uncertainty parameters were considered by 124 sampled calculations. Through 124 calculations using Mosaique program with MARS-KS code, peak cladding temperature was calculated and final PCT was determined by the 3rd order Wilks' formula. The uncertainty parameters which has strong influence were investigated by Pearson coefficient analysis. They were mostly related with plant operation and fuel material properties. Evaluation results through the 124 calculations and sensitivity analysis show that improved KINS-REM could be reasonably applicable for uncertainty evaluation with multi-dimensional model calculations of OPR1000 plants.

REM - the Shape of Potentials for f(R) Theories in Cosmology and Tachyons

CERN Document Server

Vulcanov, Dumitru N; Sporea, Ciprian A

2014-01-01

We investigated the reverse engineering method (REM) for constructing the potential of the scalar field in cosmological theories based on metric f(R) gravity and Friedman Robertson Walker (FRW) metric. Then transposing the new field and Friedman equations in an algebraic computing special library (in Maple + GrTennsorII platform) we graphically investigate the shape of the potentials in terms of the scalar field in at least two type of cosmology with exponential and linear scale factor expansion. Some perspectives and conclusions relating these results with tachyonic cosmology theories are noticed.

Predictive Modeling in Race Walking

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Krzysztof Wiktorowicz

2015-01-01

Full Text Available This paper presents the use of linear and nonlinear multivariable models as tools to support training process of race walkers. These models are calculated using data collected from race walkers’ training events and they are used to predict the result over a 3 km race based on training loads. The material consists of 122 training plans for 21 athletes. In order to choose the best model leave-one-out cross-validation method is used. The main contribution of the paper is to propose the nonlinear modifications for linear models in order to achieve smaller prediction error. It is shown that the best model is a modified LASSO regression with quadratic terms in the nonlinear part. This model has the smallest prediction error and simplified structure by eliminating some of the predictors.

Conditions associated with REM sleep behaviour disorder: Description of a hospital series.

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Abenza Abildúa, M J; Miralles Martinez, A; Arpa Gutiérrez, F J; Lores Gutiérrez, V; Algarra Lucas, C; Jimeno Montero, C; Sánchez García, B; Mata Álvarez-Santullano, M; Borrue Fernández, C; Cordero Martín, G; Gutiérrez Cueto, G; Torrecillas Narváez, M D; Thuissard Vasallo, I; Gómez Aceña, A

2017-02-16

REM sleep behaviour disorder (RBD) is characterised by violent behaviours (screaming, kicking, vivid dreams) during REM sleep. It has a prevalence of 1% to 2% of the general population and is especially frequent in men and the population older than 60. In the last decade, RBD has been suggested to be a prodrome of neurodegenerative disease. We analysed associated neurological diseases and responses to drug treatment in 33 patients with RBD treated in the multidisciplinary sleep disorders unit at Hospital Infanta Sofía. We conducted an observational descriptive retrospective analysis of patients diagnosed with RBD and treated in our multidisciplinary sleep disorders unit between October 2012 and December 2015. We recorded age, sex, associated diseases, and treatments administered to these patients. A total of 365 patients were attended at our unit, including 33 with RBD: 13 women (40%) and 20 men (60%). Mean age was 62.72 years. An associated disorder was identified in 48%, with the most common being mild cognitive impairment (69%). The percentage of patients with RBD and an associated disorder among patients older than 60 was 68%. Eighty-two percent of the patients required treatment. The most commonly used drug was clonazepam (76%), followed by melatonin (9%), gabapentin (6%), and trazodone (3%). In our series, 48% of the patients had an associated disorder. The likelihood of detecting an associated disorder increases with patients' age. The vast majority of patients required drug treatment due to symptom severity; the most frequently administered drug was clonazepam (76%). Copyright © 2017 The Author(s). Publicado por Elsevier España, S.L.U. All rights reserved.

Adding propensity scores to pure prediction models fails to improve predictive performance

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Amy S. Nowacki

2013-08-01

Full Text Available Background. Propensity score usage seems to be growing in popularity leading researchers to question the possible role of propensity scores in prediction modeling, despite the lack of a theoretical rationale. It is suspected that such requests are due to the lack of differentiation regarding the goals of predictive modeling versus causal inference modeling. Therefore, the purpose of this study is to formally examine the effect of propensity scores on predictive performance. Our hypothesis is that a multivariable regression model that adjusts for all covariates will perform as well as or better than those models utilizing propensity scores with respect to model discrimination and calibration.Methods. The most commonly encountered statistical scenarios for medical prediction (logistic and proportional hazards regression were used to investigate this research question. Random cross-validation was performed 500 times to correct for optimism. The multivariable regression models adjusting for all covariates were compared with models that included adjustment for or weighting with the propensity scores. The methods were compared based on three predictive performance measures: (1 concordance indices; (2 Brier scores; and (3 calibration curves.Results. Multivariable models adjusting for all covariates had the highest average concordance index, the lowest average Brier score, and the best calibration. Propensity score adjustment and inverse probability weighting models without adjustment for all covariates performed worse than full models and failed to improve predictive performance with full covariate adjustment.Conclusion. Propensity score techniques did not improve prediction performance measures beyond multivariable adjustment. Propensity scores are not recommended if the analytical goal is pure prediction modeling.

Model-free and model-based reward prediction errors in EEG.

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Sambrook, Thomas D; Hardwick, Ben; Wills, Andy J; Goslin, Jeremy

2018-05-24

Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain. Copyright © 2018 Elsevier Inc. All rights reserved.

Strengths and Weaknesses of McNamara's Evolutionary Psychological Model of Dreaming

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Sandra Olliges

2010-10-01

Full Text Available This article includes a brief overview of McNamara's (2004 evolutionary model of dreaming. The strengths and weaknesses of this model are then evaluated in terms of its consonance with measurable neurological and biological properties of dreaming, its fit within the tenets of evolutionary theories of dreams, and its alignment with evolutionary concepts of cooperation and spirituality. McNamara's model focuses primarily on dreaming that occurs during rapid eye movement (REM sleep; therefore this article also focuses on REM dreaming.

Nonlinear chaotic model for predicting storm surges

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M. Siek

2010-09-01

Full Text Available This paper addresses the use of the methods of nonlinear dynamics and chaos theory for building a predictive chaotic model from time series. The chaotic model predictions are made by the adaptive local models based on the dynamical neighbors found in the reconstructed phase space of the observables. We implemented the univariate and multivariate chaotic models with direct and multi-steps prediction techniques and optimized these models using an exhaustive search method. The built models were tested for predicting storm surge dynamics for different stormy conditions in the North Sea, and are compared to neural network models. The results show that the chaotic models can generally provide reliable and accurate short-term storm surge predictions.

Man-rem exposure--a forcing function in remote maintenance of nuclear plants

International Nuclear Information System (INIS)

Erion, T.L.

1979-01-01

The purpose of this paper is to show the need for remote tooling systems in order to comply with the proposed NRC strategies relative to occupational radiation exposure (ORE) during maintenance outages. In addition to developing tooling to help or remove man from a radiation environment, present efforts to make that environment a less hostile one in the future are underway. A program to decontaminate the channelhead is underway. The obvious benefit of reducing the radiation source strength, and therefore man-rem exposure, has been indicated. Specialized tooling for local decontamination purposes, development of an advanced computer-controlled manipulator, and comprehensive personnel training programs can all reduce downtime and personnel exposures

Comparison of severity of illness scoring systems in the prediction of hospital mortality in severe sepsis and septic shock

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Crowe Colleen

2010-01-01

Full Text Available Background : New scoring systems, including the Rapid Emergency Medicine Score (REMS, the Mortality in Emergency Department Sepsis (MEDS score, and the confusion, urea nitrogen, respiratory rate, blood pressure, 65 years and older (CURB-65 score, have been developed for emergency department (ED use in various patient populations. Increasing use of early goal directed therapy (EGDT for the emergent treatment of sepsis introduces a growing population of patients in which the accuracy of these scoring systems has not been widely examined. Objectives : To evaluate the ability of the REMS, MEDS score, and CURB-65 score to predict mortality in septic patients treated with modified EGDT. Materials and Methods : Secondary analysis of data from prospectively identified patients treated with modified EGDT in a large tertiary care suburban community hospital with over 85,000 ED visits annually and 700 inpatient beds, from May 2007 through May 2008. We included all patients with severe sepsis or septic shock, who were treated with our modified EGDT protocol. Our major outcome was in-hospital mortality. The performance of the scores was compared by area under the ROC curves (AUCs. Results : A total of 216 patients with severe sepsis or septic shock were treated with modified EGDT during the study period. Overall mortality was 32.9%. Calculated AUCs were 0.74 [95% confidence interval (CI: 0.67-0.81] for the MEDS score, 0.62 (95% CI: 0.54-0.69 for the REMS, and 0.59 (95% CI: 0.51-0.67 for the CURB-65 score. Conclusion : We found that all three ED-based systems for scoring severity of illness had low to moderate predictive capability. The MEDS score demonstrated the largest AUC of the studied scoring systems for the outcome of mortality, although the CIs on point estimates of the AUC of the REMS and CURB-65 scores all overlap.

Extracting falsifiable predictions from sloppy models.

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Gutenkunst, Ryan N; Casey, Fergal P; Waterfall, Joshua J; Myers, Christopher R; Sethna, James P

2007-12-01

Successful predictions are among the most compelling validations of any model. Extracting falsifiable predictions from nonlinear multiparameter models is complicated by the fact that such models are commonly sloppy, possessing sensitivities to different parameter combinations that range over many decades. Here we discuss how sloppiness affects the sorts of data that best constrain model predictions, makes linear uncertainty approximations dangerous, and introduces computational difficulties in Monte-Carlo uncertainty analysis. We also present a useful test problem and suggest refinements to the standards by which models are communicated.

Risk Factors for Neurodegeneration in Idiopathic REM sleep Behavior Disorder: A Multicenter Study

Science.gov (United States)

Postuma, RB; Iranzo, A; Hogl, B; Arnulf, I; Ferini-Strambi, L; Manni, R; Miyamoto, T.; Oertel, W; Dauvilliers, Y; Ju, Y; Puligheddu, M; Sonka, K; Pelletier, A; Santamaria, J; Frauscher, B; Leu-Semenescu, S; Zucconi, M; Terzaghi, M; Miyamoto, M.; Unger, MM; Carlander, B; Fantini, ML; Montplaisir, JY

2018-01-01

Objective To assess whether risk factors for Parkinson’s disease and Dementia with Lewy bodies increase rate of defined neurodegenerative disease in idiopathic REM sleep behavior disorder Methods 12 centers administered a detailed questionnaire assessing risk factors for neurodegenerative synucleinopathy to patients with idiopathic REM sleep behavior disorder. Variables included demographics, lifestyle factors, pesticide exposures, occupation, co-morbid conditions, medication use, family history, and autonomic/motor symptoms. After 4-years follow-up, patients were assessed for dementia or parkinsonism. Disease risk was assessed with Kaplan-Meier analysis, and epidemiologic variables were compared between convertors and those still idiopathic using logistic regression. Results Of 305 patients, follow-up information was available for 279, of whom 93 (33.3%) developed defined neurodegenerative disease. Disease risk was 25% at 3 years, and 41% after 5 years. Patients who converted were older (difference=4.5 years, pconversion. Although occupation was similar between groups, those who converted had a lower likelihood of pesticide exposure (occupational insecticide=2.3% vs. 9.0%). Convertors were more likely to report family history of dementia (OR=2.09), without significant differences in Parkinson’s disease or sleep disorders. Medication exposures and medical history were similar between groups. Autonomic and motor symptoms were more common among those who converted. Risk factors for primary dementia and parkinsonism were generally similar, except for a notably higher clonazepam use in dementia convertors (OR=2.6). Interpretation Patients with idiopathic RBD are at very high risk of neurodegenerative synucleinopathy. Risk factor profiles between convertors and non-convertors have both important commonalities and differences. PMID:25767079

Fixed recurrence and slip models better predict earthquake behavior than the time- and slip-predictable models 1: repeating earthquakes

Science.gov (United States)

Rubinstein, Justin L.; Ellsworth, William L.; Chen, Kate Huihsuan; Uchida, Naoki

2012-01-01

The behavior of individual events in repeating earthquake sequences in California, Taiwan and Japan is better predicted by a model with fixed inter-event time or fixed slip than it is by the time- and slip-predictable models for earthquake occurrence. Given that repeating earthquakes are highly regular in both inter-event time and seismic moment, the time- and slip-predictable models seem ideally suited to explain their behavior. Taken together with evidence from the companion manuscript that shows similar results for laboratory experiments we conclude that the short-term predictions of the time- and slip-predictable models should be rejected in favor of earthquake models that assume either fixed slip or fixed recurrence interval. This implies that the elastic rebound model underlying the time- and slip-predictable models offers no additional value in describing earthquake behavior in an event-to-event sense, but its value in a long-term sense cannot be determined. These models likely fail because they rely on assumptions that oversimplify the earthquake cycle. We note that the time and slip of these events is predicted quite well by fixed slip and fixed recurrence models, so in some sense they are time- and slip-predictable. While fixed recurrence and slip models better predict repeating earthquake behavior than the time- and slip-predictable models, we observe a correlation between slip and the preceding recurrence time for many repeating earthquake sequences in Parkfield, California. This correlation is not found in other regions, and the sequences with the correlative slip-predictable behavior are not distinguishable from nearby earthquake sequences that do not exhibit this behavior.

EFFICIENT PREDICTIVE MODELLING FOR ARCHAEOLOGICAL RESEARCH

OpenAIRE

Balla, A.; Pavlogeorgatos, G.; Tsiafakis, D.; Pavlidis, G.

2014-01-01

The study presents a general methodology for designing, developing and implementing predictive modelling for identifying areas of archaeological interest. The methodology is based on documented archaeological data and geographical factors, geospatial analysis and predictive modelling, and has been applied to the identification of possible Macedonian tombs’ locations in Northern Greece. The model was tested extensively and the results were validated using a commonly used predictive gain, which...

Spatial Economics Model Predicting Transport Volume

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Lu Bo

2016-10-01

Full Text Available It is extremely important to predict the logistics requirements in a scientific and rational way. However, in recent years, the improvement effect on the prediction method is not very significant and the traditional statistical prediction method has the defects of low precision and poor interpretation of the prediction model, which cannot only guarantee the generalization ability of the prediction model theoretically, but also cannot explain the models effectively. Therefore, in combination with the theories of the spatial economics, industrial economics, and neo-classical economics, taking city of Zhuanghe as the research object, the study identifies the leading industry that can produce a large number of cargoes, and further predicts the static logistics generation of the Zhuanghe and hinterlands. By integrating various factors that can affect the regional logistics requirements, this study established a logistics requirements potential model from the aspect of spatial economic principles, and expanded the way of logistics requirements prediction from the single statistical principles to an new area of special and regional economics.

Not only … but also: REM sleep creates and NREM Stage 2 instantiates landmark junctions in cortical memory networks.

Science.gov (United States)

Llewellyn, Sue; Hobson, J Allan

2015-07-01

This article argues both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep contribute to overnight episodic memory processes but their roles differ. Episodic memory may have evolved from memory for spatial navigation in animals and humans. Equally, mnemonic navigation in world and mental space may rely on fundamentally equivalent processes. Consequently, the basic spatial network characteristics of pathways which meet at omnidirectional nodes or junctions may be conserved in episodic brain networks. A pathway is formally identified with the unidirectional, sequential phases of an episodic memory. In contrast, the function of omnidirectional junctions is not well understood. In evolutionary terms, both animals and early humans undertook tours to a series of landmark junctions, to take advantage of resources (food, water and shelter), whilst trying to avoid predators. Such tours required memory for emotionally significant landmark resource-place-danger associations and the spatial relationships amongst these landmarks. In consequence, these tours may have driven the evolution of both spatial and episodic memory. The environment is dynamic. Resource-place associations are liable to shift and new resource-rich landmarks may be discovered, these changes may require re-wiring in neural networks. To realise these changes, REM may perform an associative, emotional encoding function between memory networks, engendering an omnidirectional landmark junction which is instantiated in the cortex during NREM Stage 2. In sum, REM may preplay associated elements of past episodes (rather than replay individual episodes), to engender an unconscious representation which can be used by the animal on approach to a landmark junction in wake. Copyright © 2015 Elsevier Inc. All rights reserved.

Neural Fuzzy Inference System-Based Weather Prediction Model and Its Precipitation Predicting Experiment

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Jing Lu

2014-11-01

Full Text Available We propose a weather prediction model in this article based on neural network and fuzzy inference system (NFIS-WPM, and then apply it to predict daily fuzzy precipitation given meteorological premises for testing. The model consists of two parts: the first part is the “fuzzy rule-based neural network”, which simulates sequential relations among fuzzy sets using artificial neural network; and the second part is the “neural fuzzy inference system”, which is based on the first part, but could learn new fuzzy rules from the previous ones according to the algorithm we proposed. NFIS-WPM (High Pro and NFIS-WPM (Ave are improved versions of this model. It is well known that the need for accurate weather prediction is apparent when considering the benefits. However, the excessive pursuit of accuracy in weather prediction makes some of the “accurate” prediction results meaningless and the numerical prediction model is often complex and time-consuming. By adapting this novel model to a precipitation prediction problem, we make the predicted outcomes of precipitation more accurate and the prediction methods simpler than by using the complex numerical forecasting model that would occupy large computation resources, be time-consuming and which has a low predictive accuracy rate. Accordingly, we achieve more accurate predictive precipitation results than by using traditional artificial neural networks that have low predictive accuracy.

Incorporating uncertainty in predictive species distribution modelling.

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Beale, Colin M; Lennon, Jack J

2012-01-19

Motivated by the need to solve ecological problems (climate change, habitat fragmentation and biological invasions), there has been increasing interest in species distribution models (SDMs). Predictions from these models inform conservation policy, invasive species management and disease-control measures. However, predictions are subject to uncertainty, the degree and source of which is often unrecognized. Here, we review the SDM literature in the context of uncertainty, focusing on three main classes of SDM: niche-based models, demographic models and process-based models. We identify sources of uncertainty for each class and discuss how uncertainty can be minimized or included in the modelling process to give realistic measures of confidence around predictions. Because this has typically not been performed, we conclude that uncertainty in SDMs has often been underestimated and a false precision assigned to predictions of geographical distribution. We identify areas where development of new statistical tools will improve predictions from distribution models, notably the development of hierarchical models that link different types of distribution model and their attendant uncertainties across spatial scales. Finally, we discuss the need to develop more defensible methods for assessing predictive performance, quantifying model goodness-of-fit and for assessing the significance of model covariates.

REM dream activity of insomnia sufferers: a systematic comparison with good sleepers.

Science.gov (United States)

Pérusse, Alexandra D; De Koninck, Joseph; Pedneault-Drolet, Maude; Ellis, Jason G; Bastien, Célyne H

2016-04-01

The dream activity of patients with primary insomnia (PI) has rarely been studied, especially using in-laboratory dream collection, although dreams could be linked to their state of hyperarousal and their negative waking experiences. The objective of the study was to compare patients with PI and good sleeper controls (GSCs) in terms of dream recall frequency and dream content. Polysomnography was recorded in 12 patients with PI and 12 GSCs (aged between 30 and 45 years) for five consecutive nights. Rapid eye movement (REM) sleep awakenings were enforced on nights 3 and 5 for dream collections. The REM dream collections revealed that the groups were similar in terms of dream recall frequency (p ≤ 0.7). With respect to dream content variables, the dreams of GSCs tended to comprise more positive emotions (p = 0.06), whereas the dreams of patients with PI were characterized by more negative elements than positive ones (p = 0.001). Subjectively, GSCs characterized their dreams as being more pleasant and containing more joy, happiness, and vividness (p ≤ 0.03) than patients with PI. Finally, elevated negative dream content was associated with lower sleep efficiencies in insomnia (p = 0.004). These results suggest that less positive emotions and greater negative content characterize the dreams of patients with PI, which is in line with their waking experiences. One potential explanation could be hyperarousal exacerbating presleep negative mentation, thus contributing to poorer sleep quality. The lack of difference in dream recall frequency is most likely due to the forced awakening "dream collection" procedure. The study of dream activity seems a promising avenue for understanding the 24-h experience of insomnia better and exploring the potential benefits of dream management techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

Predictive user modeling with actionable attributes

NARCIS (Netherlands)

Zliobaite, I.; Pechenizkiy, M.

2013-01-01

Different machine learning techniques have been proposed and used for modeling individual and group user needs, interests and preferences. In the traditional predictive modeling instances are described by observable variables, called attributes. The goal is to learn a model for predicting the target

Cordance derived from REM sleep EEG as a biomarker for treatment response in depression--a naturalistic study after antidepressant medication

NARCIS (Netherlands)

Adamczyk, M.; Gazea, M.; Wollweber, B.; Holsboer, F.; Dresler, M.; Steiger, A.; Pawlowski, M.

2015-01-01

OBJECTIVE: To evaluate whether prefrontal cordance in theta frequency band derived from REM sleep EEG after the first week of antidepressant medication could characterize the treatment response after 4 weeks of therapy in depressed patients. METHOD: 20 in-patients (15 females, 5 males) with a

Utilização de plantas medicinais como remédio caseiro na Atenção Primária em Blumenau, Santa Catarina, Brasil

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Ana Lúcia Bertarello Zeni

Full Text Available Resumo Na última década foi observado um aumento no uso de práticas terapêuticas alternativas apoiadas por políticas no âmbito do Sistema Único de Saúde (SUS, em particular o uso de plantas medicinais e de fitoterápicos. Este estudo investigou o uso de remédios caseiros pelos usuários da Atenção Primária da Saúde do município de Blumenau, em Santa Catarina. Estudo epidemiológico observacional seccional, cujos dados foram obtidos através de questionário aplicado a 701 indivíduos. Utilizou-se um modelo de regressão logística não condicional para estimar a associação entre uso de remédios caseiros e variáveis sociodemográficas e médicoassistenciais. Observou-se que 21,9% dos entrevistados utilizaram remédios caseiros, sendo as plantas medicinais obtidas no quintal das casas a principal escolha. Como as mais citadas destacaram-se erva-cidreira, camomila, hortelã e limão. O uso de remédios caseiros se mostrou associado ao sexo feminino, à idade mais avançada e à modalidade de serviço, Estratégia Saúde da Família. Os resultados mostraram que as plantas medicinais são utilizadas como alternativa terapêutica. Entretanto, é necessário que os serviços de atenção primária garantam o acesso aos produtos naturais, bem como profissionais qualificados capazes de fornecer orientações sobre sua utilização.

Activated aging dynamics and effective trap model description in the random energy model

Science.gov (United States)

Baity-Jesi, M.; Biroli, G.; Cammarota, C.

2018-01-01

We study the out-of-equilibrium aging dynamics of the random energy model (REM) ruled by a single spin-flip Metropolis dynamics. We focus on the dynamical evolution taking place on time-scales diverging with the system size. Our aim is to show to what extent the activated dynamics displayed by the REM can be described in terms of an effective trap model. We identify two time regimes: the first one corresponds to the process of escaping from a basin in the energy landscape and to the subsequent exploration of high energy configurations, whereas the second one corresponds to the evolution from a deep basin to the other. By combining numerical simulations with analytical arguments we show why the trap model description does not hold in the former but becomes exact in the second.

MJO prediction skill of the subseasonal-to-seasonal (S2S) prediction models

Science.gov (United States)

Son, S. W.; Lim, Y.; Kim, D.

2017-12-01

The Madden-Julian Oscillation (MJO), the dominant mode of tropical intraseasonal variability, provides the primary source of tropical and extratropical predictability on subseasonal to seasonal timescales. To better understand its predictability, this study conducts quantitative evaluation of MJO prediction skill in the state-of-the-art operational models participating in the subseasonal-to-seasonal (S2S) prediction project. Based on bivariate correlation coefficient of 0.5, the S2S models exhibit MJO prediction skill ranging from 12 to 36 days. These prediction skills are affected by both the MJO amplitude and phase errors, the latter becoming more important with forecast lead times. Consistent with previous studies, the MJO events with stronger initial amplitude are typically better predicted. However, essentially no sensitivity to the initial MJO phase is observed. Overall MJO prediction skill and its inter-model spread are further related with the model mean biases in moisture fields and longwave cloud-radiation feedbacks. In most models, a dry bias quickly builds up in the deep tropics, especially across the Maritime Continent, weakening horizontal moisture gradient. This likely dampens the organization and propagation of MJO. Most S2S models also underestimate the longwave cloud-radiation feedbacks in the tropics, which may affect the maintenance of the MJO convective envelop. In general, the models with a smaller bias in horizontal moisture gradient and longwave cloud-radiation feedbacks show a higher MJO prediction skill, suggesting that improving those processes would enhance MJO prediction skill.

Evaluating Predictive Uncertainty of Hyporheic Exchange Modelling

Science.gov (United States)

Chow, R.; Bennett, J.; Dugge, J.; Wöhling, T.; Nowak, W.

2017-12-01

Hyporheic exchange is the interaction of water between rivers and groundwater, and is difficult to predict. One of the largest contributions to predictive uncertainty for hyporheic fluxes have been attributed to the representation of heterogeneous subsurface properties. This research aims to evaluate which aspect of the subsurface representation - the spatial distribution of hydrofacies or the model for local-scale (within-facies) heterogeneity - most influences the predictive uncertainty. Also, we seek to identify data types that help reduce this uncertainty best. For this investigation, we conduct a modelling study of the Steinlach River meander, in Southwest Germany. The Steinlach River meander is an experimental site established in 2010 to monitor hyporheic exchange at the meander scale. We use HydroGeoSphere, a fully integrated surface water-groundwater model, to model hyporheic exchange and to assess the predictive uncertainty of hyporheic exchange transit times (HETT). A highly parameterized complex model is built and treated as `virtual reality', which is in turn modelled with simpler subsurface parameterization schemes (Figure). Then, we conduct Monte-Carlo simulations with these models to estimate the predictive uncertainty. Results indicate that: Uncertainty in HETT is relatively small for early times and increases with transit times. Uncertainty from local-scale heterogeneity is negligible compared to uncertainty in the hydrofacies distribution. Introducing more data to a poor model structure may reduce predictive variance, but does not reduce predictive bias. Hydraulic head observations alone cannot constrain the uncertainty of HETT, however an estimate of hyporheic exchange flux proves to be more effective at reducing this uncertainty. Figure: Approach for evaluating predictive model uncertainty. A conceptual model is first developed from the field investigations. A complex model (`virtual reality') is then developed based on that conceptual model

The extended range neutron rem counter LINUS: overview and latest developments

International Nuclear Information System (INIS)

Birattari, C.; Rancati, T.; Esposito, A.; Pelliccioni, M.; Ferrari, A.; Silari, M.

1997-01-01

The 'history' of the extended range neutron rem counter LINUS, since its first conception in 1990 is reviewed, along with the latest developments. These include the calibration of the initially cylindrical version with nearly monoenergetic neutrons in the energy range 34-66 MeV, a detailed evaluation of the anisotropy of its response function, the construction and calibration of an improved spherical version, and recent measurements in reference high energy stray radiation fields. The instrument can now be considered as being fully characterized. Similar monitors built by other laboratories following the present design have confirmed its performances. The instrument is now in semi-routine use at a number of particle accelerator facilities and is one of several devices used on-board of aircrafts for assessing the exposure to cosmic rays at commercial flight altitudes. (author)

Modeling, robust and distributed model predictive control for freeway networks

NARCIS (Netherlands)

Liu, S.

2016-01-01

In Model Predictive Control (MPC) for traffic networks, traffic models are crucial since they are used as prediction models for determining the optimal control actions. In order to reduce the computational complexity of MPC for traffic networks, macroscopic traffic models are often used instead of

Staying Power of Churn Prediction Models

NARCIS (Netherlands)

Risselada, Hans; Verhoef, Peter C.; Bijmolt, Tammo H. A.

In this paper, we study the staying power of various churn prediction models. Staying power is defined as the predictive performance of a model in a number of periods after the estimation period. We examine two methods, logit models and classification trees, both with and without applying a bagging

DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

Science.gov (United States)

Aslam; Matysiak, W; Atanackovic, J; Waker, A J

2012-06-01

This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

Occupational Attitude Inventory: Use in Predictions of Job Satisfaction, Reenlistment Intent, and Reenlistment Behavior.

Science.gov (United States)

1982-10-01

business and industry for these entry level manpower resources. For this reason tie services must make all even more concentrated effort to keep...listmnent betweetn eligible- inteligible and eligible ony leerlier reported pattern con tiinued. namtely that prediction appeared to bei better aniong...numiber of extra (lit ies individunals have to perform. are coiitlinuously rem oved by organizatiois Ii thle normal course of their business .Air * Force

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

Prediction Models for Dynamic Demand Response

Energy Technology Data Exchange (ETDEWEB)

Aman, Saima; Frincu, Marc; Chelmis, Charalampos; Noor, Muhammad; Simmhan, Yogesh; Prasanna, Viktor K.

2015-11-02

As Smart Grids move closer to dynamic curtailment programs, Demand Response (DR) events will become necessary not only on fixed time intervals and weekdays predetermined by static policies, but also during changing decision periods and weekends to react to real-time demand signals. Unique challenges arise in this context vis-a-vis demand prediction and curtailment estimation and the transformation of such tasks into an automated, efficient dynamic demand response (D²R) process. While existing work has concentrated on increasing the accuracy of prediction models for DR, there is a lack of studies for prediction models for D²R, which we address in this paper. Our first contribution is the formal definition of D²R, and the description of its challenges and requirements. Our second contribution is a feasibility analysis of very-short-term prediction of electricity consumption for D²R over a diverse, large-scale dataset that includes both small residential customers and large buildings. Our third, and major contribution is a set of insights into the predictability of electricity consumption in the context of D²R. Specifically, we focus on prediction models that can operate at a very small data granularity (here 15-min intervals), for both weekdays and weekends - all conditions that characterize scenarios for D²R. We find that short-term time series and simple averaging models used by Independent Service Operators and utilities achieve superior prediction accuracy. We also observe that workdays are more predictable than weekends and holiday. Also, smaller customers have large variation in consumption and are less predictable than larger buildings. Key implications of our findings are that better models are required for small customers and for non-workdays, both of which are critical for D²R. Also, prediction models require just few days’ worth of data indicating that small amounts of

Genomic prediction of complex human traits: relatedness, trait architecture and predictive meta-models

Science.gov (United States)

Spiliopoulou, Athina; Nagy, Reka; Bermingham, Mairead L.; Huffman, Jennifer E.; Hayward, Caroline; Vitart, Veronique; Rudan, Igor; Campbell, Harry; Wright, Alan F.; Wilson, James F.; Pong-Wong, Ricardo; Agakov, Felix; Navarro, Pau; Haley, Chris S.

2015-01-01

We explore the prediction of individuals' phenotypes for complex traits using genomic data. We compare several widely used prediction models, including Ridge Regression, LASSO and Elastic Nets estimated from cohort data, and polygenic risk scores constructed using published summary statistics from genome-wide association meta-analyses (GWAMA). We evaluate the interplay between relatedness, trait architecture and optimal marker density, by predicting height, body mass index (BMI) and high-density lipoprotein level (HDL) in two data cohorts, originating from Croatia and Scotland. We empirically demonstrate that dense models are better when all genetic effects are small (height and BMI) and target individuals are related to the training samples, while sparse models predict better in unrelated individuals and when some effects have moderate size (HDL). For HDL sparse models achieved good across-cohort prediction, performing similarly to the GWAMA risk score and to models trained within the same cohort, which indicates that, for predicting traits with moderately sized effects, large sample sizes and familial structure become less important, though still potentially useful. Finally, we propose a novel ensemble of whole-genome predictors with GWAMA risk scores and demonstrate that the resulting meta-model achieves higher prediction accuracy than either model on its own. We conclude that although current genomic predictors are not accurate enough for diagnostic purposes, performance can be improved without requiring access to large-scale individual-level data. Our methodologically simple meta-model is a means of performing predictive meta-analysis for optimizing genomic predictions and can be easily extended to incorporate multiple population-level summary statistics or other domain knowledge. PMID:25918167

Accuracy assessment of landslide prediction models

International Nuclear Information System (INIS)

Othman, A N; Mohd, W M N W; Noraini, S

2014-01-01

The increasing population and expansion of settlements over hilly areas has greatly increased the impact of natural disasters such as landslide. Therefore, it is important to developed models which could accurately predict landslide hazard zones. Over the years, various techniques and models have been developed to predict landslide hazard zones. The aim of this paper is to access the accuracy of landslide prediction models developed by the authors. The methodology involved the selection of study area, data acquisition, data processing and model development and also data analysis. The development of these models are based on nine different landslide inducing parameters i.e. slope, land use, lithology, soil properties, geomorphology, flow accumulation, aspect, proximity to river and proximity to road. Rank sum, rating, pairwise comparison and AHP techniques are used to determine the weights for each of the parameters used. Four (4) different models which consider different parameter combinations are developed by the authors. Results obtained are compared to landslide history and accuracies for Model 1, Model 2, Model 3 and Model 4 are 66.7, 66.7%, 60% and 22.9% respectively. From the results, rank sum, rating and pairwise comparison can be useful techniques to predict landslide hazard zones

Mental models accurately predict emotion transitions.

Science.gov (United States)

Thornton, Mark A; Tamir, Diana I

2017-06-06

Successful social interactions depend on people's ability to predict others' future actions and emotions. People possess many mechanisms for perceiving others' current emotional states, but how might they use this information to predict others' future states? We hypothesized that people might capitalize on an overlooked aspect of affective experience: current emotions predict future emotions. By attending to regularities in emotion transitions, perceivers might develop accurate mental models of others' emotional dynamics. People could then use these mental models of emotion transitions to predict others' future emotions from currently observable emotions. To test this hypothesis, studies 1-3 used data from three extant experience-sampling datasets to establish the actual rates of emotional transitions. We then collected three parallel datasets in which participants rated the transition likelihoods between the same set of emotions. Participants' ratings of emotion transitions predicted others' experienced transitional likelihoods with high accuracy. Study 4 demonstrated that four conceptual dimensions of mental state representation-valence, social impact, rationality, and human mind-inform participants' mental models. Study 5 used 2 million emotion reports on the Experience Project to replicate both of these findings: again people reported accurate models of emotion transitions, and these models were informed by the same four conceptual dimensions. Importantly, neither these conceptual dimensions nor holistic similarity could fully explain participants' accuracy, suggesting that their mental models contain accurate information about emotion dynamics above and beyond what might be predicted by static emotion knowledge alone.

Mental models accurately predict emotion transitions

Science.gov (United States)

Thornton, Mark A.; Tamir, Diana I.

2017-01-01

Successful social interactions depend on people’s ability to predict others’ future actions and emotions. People possess many mechanisms for perceiving others’ current emotional states, but how might they use this information to predict others’ future states? We hypothesized that people might capitalize on an overlooked aspect of affective experience: current emotions predict future emotions. By attending to regularities in emotion transitions, perceivers might develop accurate mental models of others’ emotional dynamics. People could then use these mental models of emotion transitions to predict others’ future emotions from currently observable emotions. To test this hypothesis, studies 1–3 used data from three extant experience-sampling datasets to establish the actual rates of emotional transitions. We then collected three parallel datasets in which participants rated the transition likelihoods between the same set of emotions. Participants’ ratings of emotion transitions predicted others’ experienced transitional likelihoods with high accuracy. Study 4 demonstrated that four conceptual dimensions of mental state representation—valence, social impact, rationality, and human mind—inform participants’ mental models. Study 5 used 2 million emotion reports on the Experience Project to replicate both of these findings: again people reported accurate models of emotion transitions, and these models were informed by the same four conceptual dimensions. Importantly, neither these conceptual dimensions nor holistic similarity could fully explain participants’ accuracy, suggesting that their mental models contain accurate information about emotion dynamics above and beyond what might be predicted by static emotion knowledge alone. PMID:28533373

Poisson Mixture Regression Models for Heart Disease Prediction.

Science.gov (United States)

Mufudza, Chipo; Erol, Hamza

2016-01-01

Early heart disease control can be achieved by high disease prediction and diagnosis efficiency. This paper focuses on the use of model based clustering techniques to predict and diagnose heart disease via Poisson mixture regression models. Analysis and application of Poisson mixture regression models is here addressed under two different classes: standard and concomitant variable mixture regression models. Results show that a two-component concomitant variable Poisson mixture regression model predicts heart disease better than both the standard Poisson mixture regression model and the ordinary general linear Poisson regression model due to its low Bayesian Information Criteria value. Furthermore, a Zero Inflated Poisson Mixture Regression model turned out to be the best model for heart prediction over all models as it both clusters individuals into high or low risk category and predicts rate to heart disease componentwise given clusters available. It is deduced that heart disease prediction can be effectively done by identifying the major risks componentwise using Poisson mixture regression model.

Poisson Mixture Regression Models for Heart Disease Prediction

Science.gov (United States)

Erol, Hamza

2016-01-01

Early heart disease control can be achieved by high disease prediction and diagnosis efficiency. This paper focuses on the use of model based clustering techniques to predict and diagnose heart disease via Poisson mixture regression models. Analysis and application of Poisson mixture regression models is here addressed under two different classes: standard and concomitant variable mixture regression models. Results show that a two-component concomitant variable Poisson mixture regression model predicts heart disease better than both the standard Poisson mixture regression model and the ordinary general linear Poisson regression model due to its low Bayesian Information Criteria value. Furthermore, a Zero Inflated Poisson Mixture Regression model turned out to be the best model for heart prediction over all models as it both clusters individuals into high or low risk category and predicts rate to heart disease componentwise given clusters available. It is deduced that heart disease prediction can be effectively done by identifying the major risks componentwise using Poisson mixture regression model. PMID:27999611

Comparisons of Faulting-Based Pavement Performance Prediction Models

Directory of Open Access Journals (Sweden)

Weina Wang

2017-01-01

Full Text Available Faulting prediction is the core of concrete pavement maintenance and design. Highway agencies are always faced with the problem of lower accuracy for the prediction which causes costly maintenance. Although many researchers have developed some performance prediction models, the accuracy of prediction has remained a challenge. This paper reviews performance prediction models and JPCP faulting models that have been used in past research. Then three models including multivariate nonlinear regression (MNLR model, artificial neural network (ANN model, and Markov Chain (MC model are tested and compared using a set of actual pavement survey data taken on interstate highway with varying design features, traffic, and climate data. It is found that MNLR model needs further recalibration, while the ANN model needs more data for training the network. MC model seems a good tool for pavement performance prediction when the data is limited, but it is based on visual inspections and not explicitly related to quantitative physical parameters. This paper then suggests that the further direction for developing the performance prediction model is incorporating the advantages and disadvantages of different models to obtain better accuracy.

Unreachable Setpoints in Model Predictive Control

DEFF Research Database (Denmark)

Rawlings, James B.; Bonné, Dennis; Jørgensen, John Bagterp

2008-01-01

In this work, a new model predictive controller is developed that handles unreachable setpoints better than traditional model predictive control methods. The new controller induces an interesting fast/slow asymmetry in the tracking response of the system. Nominal asymptotic stability of the optimal...... steady state is established for terminal constraint model predictive control (MPC). The region of attraction is the steerable set. Existing analysis methods for closed-loop properties of MPC are not applicable to this new formulation, and a new analysis method is developed. It is shown how to extend...

Association between REM sleep behaviour disorder and impulse control disorder in patients with Parkinson's disease.

Science.gov (United States)

Bellosta Diago, E; Lopez Del Val, L J; Santos Lasaosa, S; López Garcia, E; Viloria Alebesque, A

2017-10-01

The relationship between impulse control disorder (ICD) and REM sleep behaviour disorder (RBD) has not yet been clarified, and the literature reports contradictory results. Our purpose is to analyse the association between these 2 disorders and their presence in patients under dopaminergic treatment. A total of 73 patients diagnosed with Parkinson's disease and treated with a single dopamine agonist were included in the study after undergoing clinical assessment and completing the single-question screen for REM sleep behaviour disorder and the short version of the questionnaire for impulsive-compulsive behaviours in Parkinson's disease. Mean age was 68.88 ± 7.758 years. Twenty-six patients (35.6%) were classified as probable-RBD. This group showed a significant association with ICD (P=.001) and had a higher prevalence of non-tremor akinetic rigid syndrome and longer duration of treatment with levodopa and dopamine agonists than the group without probable-RBD. We found a significant correlation between the use of oral dopamine agonists and ICD. Likewise, patients treated with oral dopamine agonists demonstrated a greater tendency toward presenting probable-RBD than patients taking dopamine agonists by other routes; the difference was non-significant. The present study confirms the association between RBD and a higher risk of developing symptoms of ICD in Parkinson's disease. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Comparison of model results obtained with several European regional air quality models

NARCIS (Netherlands)

Hass, H.; Builtjes, P.J.H.; Simpson, D.; Stern, R.

1997-01-01

An intercomparison study has been performed with four photo-oxidant dispersion models (EMEP, EURAD, LOTOS and REM3) which are currently capable of performing photo-oxidant formation calculations over larger path of Europe. The models, in principle, were run in the mode in which they are normally

REM sleep behaviour disorder: prodromal and mechanistic insights for Parkinson's disease.

Science.gov (United States)

Tekriwal, Anand; Kern, Drew S; Tsai, Jean; Ince, Nuri F; Wu, Jianping; Thompson, John A; Abosch, Aviva

2017-05-01

Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterised by complex motor enactment of dreams and is a potential prodromal marker of Parkinson's disease (PD). Of note, patients with PD observed during RBD episodes exhibit improved motor function, relative to baseline states during wake periods. Here, we review recent epidemiological and mechanistic findings supporting the prodromal value of RBD for PD, incorporating clinical and electrophysiological studies. Explanations for the improved motor function during RBD episodes are evaluated in light of recent publications. In addition, we present preliminary findings describing changes in the activity of the basal ganglia across the sleep-wake cycle that contribute to our understanding of RBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Estimating Model Prediction Error: Should You Treat Predictions as Fixed or Random?

Science.gov (United States)

Wallach, Daniel; Thorburn, Peter; Asseng, Senthold; Challinor, Andrew J.; Ewert, Frank; Jones, James W.; Rotter, Reimund; Ruane, Alexander

2016-01-01

Crop models are important tools for impact assessment of climate change, as well as for exploring management options under current climate. It is essential to evaluate the uncertainty associated with predictions of these models. We compare two criteria of prediction error; MSEP fixed, which evaluates mean squared error of prediction for a model with fixed structure, parameters and inputs, and MSEP uncertain( X), which evaluates mean squared error averaged over the distributions of model structure, inputs and parameters. Comparison of model outputs with data can be used to estimate the former. The latter has a squared bias term, which can be estimated using hindcasts, and a model variance term, which can be estimated from a simulation experiment. The separate contributions to MSEP uncertain (X) can be estimated using a random effects ANOVA. It is argued that MSEP uncertain (X) is the more informative uncertainty criterion, because it is specific to each prediction situation.

Risk terrain modeling predicts child maltreatment.

Science.gov (United States)

Daley, Dyann; Bachmann, Michael; Bachmann, Brittany A; Pedigo, Christian; Bui, Minh-Thuy; Coffman, Jamye

2016-12-01

As indicated by research on the long-term effects of adverse childhood experiences (ACEs), maltreatment has far-reaching consequences for affected children. Effective prevention measures have been elusive, partly due to difficulty in identifying vulnerable children before they are harmed. This study employs Risk Terrain Modeling (RTM), an analysis of the cumulative effect of environmental factors thought to be conducive for child maltreatment, to create a highly accurate prediction model for future substantiated child maltreatment cases in the City of Fort Worth, Texas. The model is superior to commonly used hotspot predictions and more beneficial in aiding prevention efforts in a number of ways: 1) it identifies the highest risk areas for future instances of child maltreatment with improved precision and accuracy; 2) it aids the prioritization of risk-mitigating efforts by informing about the relative importance of the most significant contributing risk factors; 3) since predictions are modeled as a function of easily obtainable data, practitioners do not have to undergo the difficult process of obtaining official child maltreatment data to apply it; 4) the inclusion of a multitude of environmental risk factors creates a more robust model with higher predictive validity; and, 5) the model does not rely on a retrospective examination of past instances of child maltreatment, but adapts predictions to changing environmental conditions. The present study introduces and examines the predictive power of this new tool to aid prevention efforts seeking to improve the safety, health, and wellbeing of vulnerable children. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Case studies in archaeological predictive modelling

NARCIS (Netherlands)

Verhagen, Jacobus Wilhelmus Hermanus Philippus

2007-01-01

In this thesis, a collection of papers is put together dealing with various quantitative aspects of predictive modelling and archaeological prospection. Among the issues covered are the effects of survey bias on the archaeological data used for predictive modelling, and the complexities of testing

Fingerprint verification prediction model in hand dermatitis.

Science.gov (United States)

Lee, Chew K; Chang, Choong C; Johor, Asmah; Othman, Puwira; Baba, Roshidah

2015-07-01

Hand dermatitis associated fingerprint changes is a significant problem and affects fingerprint verification processes. This study was done to develop a clinically useful prediction model for fingerprint verification in patients with hand dermatitis. A case-control study involving 100 patients with hand dermatitis. All patients verified their thumbprints against their identity card. Registered fingerprints were randomized into a model derivation and model validation group. Predictive model was derived using multiple logistic regression. Validation was done using the goodness-of-fit test. The fingerprint verification prediction model consists of a major criterion (fingerprint dystrophy area of ≥ 25%) and two minor criteria (long horizontal lines and long vertical lines). The presence of the major criterion predicts it will almost always fail verification, while presence of both minor criteria and presence of one minor criterion predict high and low risk of fingerprint verification failure, respectively. When none of the criteria are met, the fingerprint almost always passes the verification. The area under the receiver operating characteristic curve was 0.937, and the goodness-of-fit test showed agreement between the observed and expected number (P = 0.26). The derived fingerprint verification failure prediction model is validated and highly discriminatory in predicting risk of fingerprint verification in patients with hand dermatitis. © 2014 The International Society of Dermatology.

Finding Furfural Hydrogenation Catalysts via Predictive Modelling.

Science.gov (United States)

Strassberger, Zea; Mooijman, Maurice; Ruijter, Eelco; Alberts, Albert H; Maldonado, Ana G; Orru, Romano V A; Rothenberg, Gadi

2010-09-10

We combine multicomponent reactions, catalytic performance studies and predictive modelling to find transfer hydrogenation catalysts. An initial set of 18 ruthenium-carbene complexes were synthesized and screened in the transfer hydrogenation of furfural to furfurol with isopropyl alcohol complexes gave varied yields, from 62% up to >99.9%, with no obvious structure/activity correlations. Control experiments proved that the carbene ligand remains coordinated to the ruthenium centre throughout the reaction. Deuterium-labelling studies showed a secondary isotope effect (k(H):k(D)=1.5). Further mechanistic studies showed that this transfer hydrogenation follows the so-called monohydride pathway. Using these data, we built a predictive model for 13 of the catalysts, based on 2D and 3D molecular descriptors. We tested and validated the model using the remaining five catalysts (cross-validation, R(2)=0.913). Then, with this model, the conversion and selectivity were predicted for four completely new ruthenium-carbene complexes. These four catalysts were then synthesized and tested. The results were within 3% of the model's predictions, demonstrating the validity and value of predictive modelling in catalyst optimization.

Model Predictive Control for Smart Energy Systems

DEFF Research Database (Denmark)

Halvgaard, Rasmus

pumps, heat tanks, electrical vehicle battery charging/discharging, wind farms, power plants). 2.Embed forecasting methodologies for the weather (e.g. temperature, solar radiation), the electricity consumption, and the electricity price in a predictive control system. 3.Develop optimization algorithms....... Chapter 3 introduces Model Predictive Control (MPC) including state estimation, filtering and prediction for linear models. Chapter 4 simulates the models from Chapter 2 with the certainty equivalent MPC from Chapter 3. An economic MPC minimizes the costs of consumption based on real electricity prices...... that determined the flexibility of the units. A predictive control system easily handles constraints, e.g. limitations in power consumption, and predicts the future behavior of a unit by integrating predictions of electricity prices, consumption, and weather variables. The simulations demonstrate the expected...

NREM sleep hypersomnia and reduced sleep/wake continuity in a neuroendocrine mouse model of anxiety/depression based on chronic corticosterone administration.

Science.gov (United States)

Le Dantec, Y; Hache, G; Guilloux, J P; Guiard, B P; David, D J; Adrien, J; Escourrou, P

2014-08-22

Sleep/wake disorders are frequently associated with anxiety and depression and to elevated levels of cortisol. Even though these alterations are increasingly sought in animal models, no study has investigated the specific effects of chronic corticosterone (CORT) administration on sleep. We characterized sleep/wake disorders in a neuroendocrine mouse model of anxiety/depression, based on chronic CORT administration in the drinking water (35 μg/ml for 4 weeks, "CORT model"). The CORT model was markedly affected during the dark phase by non-rapid eye movement sleep (NREM) increase without consistent alteration of rapid eye movement (REM) sleep. Total sleep duration (SD) and sleep efficiency (SE) increased concomitantly during both the 24h and the dark phase, due to the increase in the number of NREM sleep episodes without a change in their mean duration. Conversely, the total duration of wake decreased due to a decrease in the mean duration of wake episodes despite an increase in their number. These results reflect hypersomnia by intrusion of NREM sleep during the active period as well as a decrease in sleep/wake continuity. In addition, NREM sleep was lighter, with an increased electroencephalogram (EEG) theta activity. With regard to REM sleep, the number and the duration of episodes decreased, specifically during the first part of the light period. REM and NREM sleep changes correlated respectively with the anxiety and the anxiety/depressive-like phenotypes, supporting the notion that studying sleep could be of predictive value for altered emotional behavior. The chronic CORT model in mice that displays hallmark characteristics of anxiety and depression provides an insight into understanding the changes in overall sleep architecture that occur under pathological conditions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Cordance derived from REM sleep EEG as a biomarker for treatment response in depression--a naturalistic study after antidepressant medication.

Science.gov (United States)

Adamczyk, Marek; Gazea, Mary; Wollweber, Bastian; Holsboer, Florian; Dresler, Martin; Steiger, Axel; Pawlowski, Marcel

2015-04-01

To evaluate whether prefrontal cordance in theta frequency band derived from REM sleep EEG after the first week of antidepressant medication could characterize the treatment response after 4 weeks of therapy in depressed patients. 20 in-patients (15 females, 5 males) with a depressive episode and 20 healthy matched controls were recruited into 4-week, open label, case-control study. Patients were treated with various antidepressants. No significant differences in age (responders (mean ± SD): 45 ± 22) years; non-responders: 49 ± 12 years), medication or Hamilton Depression Rating Scale (HAM-D) score (responders: 23.8 ± 4.5; non-responders 24.5 ± 7.6) at inclusion into the study were found between responders and non-responders. Response to treatment was defined as a ≥50% reduction of HAM-D score at the end of four weeks of active medication. Sleep EEG of patients was recorded after the first and the fourth week of medication. Cordance was computed for prefrontal EEG channels in theta frequency band during tonic REM sleep. The group of 8 responders had significantly higher prefrontal theta cordance in relation to the group of 12 non-responders after the first week of antidepressant medication. This finding was significant also when controlling for age, gender and number of previous depressive episodes (F1,15 = 6.025, P = .027). Furthermore, prefrontal cordance of all patients showed significant positive correlation (r = 0.52; P = .019) with the improvement of HAM-D score between the inclusion week and fourth week of medication. The results suggest that prefrontal cordance derived from REM sleep EEG could provide a biomarker for the response to antidepressant treatment in depressed patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Daytime Ayahuasca administration modulates REM and slow-wave sleep in healthy volunteers.

Science.gov (United States)

Barbanoj, Manel J; Riba, Jordi; Clos, S; Giménez, S; Grasa, E; Romero, S

2008-02-01

Ayahuasca is a traditional South American psychoactive beverage and the central sacrament of Brazilian-based religious groups, with followers in Europe and the United States. The tea contains the psychedelic indole N,N-dimethyltryptamine (DMT) and beta-carboline alkaloids with monoamine oxidase-inhibiting properties that render DMT orally active. DMT interacts with serotonergic neurotransmission acting as a partial agonist at 5-HT(1A) and 5-HT(2A/2C) receptor sites. Given the role played by serotonin in the regulation of the sleep/wake cycle, we investigated the effects of daytime ayahuasca consumption in sleep parameters. Subjective sleep quality, polysomnography (PSG), and spectral analysis were assessed in a group of 22 healthy male volunteers after the administration of a placebo, an ayahuasca dose equivalent to 1 mg DMT kg(-1) body weight, and 20 mg d-amphetamine, a proaminergic drug, as a positive control. Results show that ayahuasca did not induce any subjectively perceived deterioration of sleep quality or PSG-measured disruptions of sleep initiation or maintenance, in contrast with d-amphetamine, which delayed sleep initiation, disrupted sleep maintenance, induced a predominance of 'light' vs 'deep' sleep and significantly impaired subjective sleep quality. PSG analysis also showed that similarly to d-amphetamine, ayahuasca inhibits rapid eye movement (REM) sleep, decreasing its duration, both in absolute values and as a percentage of total sleep time, and shows a trend increase in its onset latency. Spectral analysis showed that d-amphetamine and ayahuasca increased power in the high frequency range, mainly during stage 2. Remarkably, whereas slow-wave sleep (SWS) power in the first night cycle, an indicator of sleep pressure, was decreased by d-amphetamine, ayahuasca enhanced power in this frequency band. Results show that daytime serotonergic psychedelic drug administration leads to measurable changes in PSG and sleep power spectrum and suggest an

Exposure to dim artificial light at night increases REM sleep and awakenings in humans.

Science.gov (United States)

Cho, Chul-Hyun; Lee, Heon-Jeong; Yoon, Ho-Kyoung; Kang, Seung-Gul; Bok, Ki-Nam; Jung, Ki-Young; Kim, Leen; Lee, Eun-Il

2016-01-01

Exposure to artificial light at night (ALAN) has become increasing common, especially in developed countries. We investigated the effect of dALAN exposure during sleep in healthy young male subjects. A total of 30 healthy young male volunteers from 21 to 29 years old were recruited for the study. They were randomly divided into two groups depending on light intensity (Group A: 5 lux and Group B: 10 lux). After a quality control process, 23 healthy subjects were included in the study (Group A: 11 subjects, Group B: 12 subjects). Subjects underwent an NPSG session with no light (Night 1) followed by an NPSG session randomly assigned to two different dim light conditions (5 or 10 lux, dom λ: 501.4 nm) for a whole night (Night 2). We found significant sleep structural differences between Nights 1 and 2, but no difference between Groups A and B. Exposure to dALAN during sleep was significantly associated with increased wake time after sleep onset (WASO; F = 7.273, p = 0.014), increased Stage N1 (F = 4.524, p = 0.045), decreased Stage N2 (F = 9.49, p = 0.006), increased Stage R (F = 6.698, p = 0.017) and non-significantly decreased REM density (F = 4.102, p = 0.056). We found that dALAN during sleep affects sleep structure. Exposure to dALAN during sleep increases the frequency of arousals, amount of shallow sleep and amount of REM sleep. This suggests adverse effects of dALAN during sleep on sleep quality and suggests the need to avoid exposure to dALAN during sleep.

REM meter for pulsed sources of neutrons

International Nuclear Information System (INIS)

Thorngate, J.E.; Hunt, G.F.; Rueppel, D.W.

1980-01-01

A rem meter was constructed specifically for measuring neutrons produced by fusion experiments for which the source pulses last 10 ms or longer. The detector is a 6 Li glass scintillator, 25.4 mm in diameter and 3.2 mm thick, surrounded by 11.5 cm of polyethylene. This detector has a sensitivity of 8.5 x 10 4 counts/mrem. The signals from this fast scintillator are shaped using a shorted delay line to produce pulses that are only 10 ns long so that dose equivalent rates up to 12 mrem/s can be measured with less than a 1% counting loss. The associated electronic circuits store detector counts only when the count rate exceeds a preset level. When the count rate returns to background, a conversion from counts to dose equivalent is made and the results are displayed. As a means of recording the number of source pulses that have occurred, a second display shows how many times the preset count rate has been exceeded. Accumulation of detector counts and readouts can also be controlled manually. The unit will display the integrated dose equilavent up to 200 mrem in 0.01 mrem steps. A pulse-height discriminator rejects gamma-ray interactions below 1 MeV, and the detector size limits the response above that energy. The instrument can be operated from an ac line or will run on rechargeable batteries for up to 12 hours

Prediction skill of rainstorm events over India in the TIGGE weather prediction models

Science.gov (United States)

Karuna Sagar, S.; Rajeevan, M.; Vijaya Bhaskara Rao, S.; Mitra, A. K.

2017-12-01

Extreme rainfall events pose a serious threat of leading to severe floods in many countries worldwide. Therefore, advance prediction of its occurrence and spatial distribution is very essential. In this paper, an analysis has been made to assess the skill of numerical weather prediction models in predicting rainstorms over India. Using gridded daily rainfall data set and objective criteria, 15 rainstorms were identified during the monsoon season (June to September). The analysis was made using three TIGGE (THe Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble) models. The models considered are the European Centre for Medium-Range Weather Forecasts (ECMWF), National Centre for Environmental Prediction (NCEP) and the UK Met Office (UKMO). Verification of the TIGGE models for 43 observed rainstorm days from 15 rainstorm events has been made for the period 2007-2015. The comparison reveals that rainstorm events are predictable up to 5 days in advance, however with a bias in spatial distribution and intensity. The statistical parameters like mean error (ME) or Bias, root mean square error (RMSE) and correlation coefficient (CC) have been computed over the rainstorm region using the multi-model ensemble (MME) mean. The study reveals that the spread is large in ECMWF and UKMO followed by the NCEP model. Though the ensemble spread is quite small in NCEP, the ensemble member averages are not well predicted. The rank histograms suggest that the forecasts are under prediction. The modified Contiguous Rain Area (CRA) technique was used to verify the spatial as well as the quantitative skill of the TIGGE models. Overall, the contribution from the displacement and pattern errors to the total RMSE is found to be more in magnitude. The volume error increases from 24 hr forecast to 48 hr forecast in all the three models.

Validation of the System One RemStar Auto A-Flex for Obstructive Sleep Apnea Treatment and Detection of Residual Apnea-Hypopnea Index

DEFF Research Database (Denmark)

Gagnadoux, Frédéric; Pevernagie, Dirk; Jennum, Poul

2017-01-01

the performance of the System One RemStar Auto A-Flex (Philips Respironics, Murrysville, PA, USA) automatically adjusted positive airway pressure (APAP) mode to manually titrated, fixed pressure CPAP and to validate the device's breathing event detection capabilities against attended in-laboratory PSG. METHODS...

Predicting climate-induced range shifts: model differences and model reliability.

Science.gov (United States)

Joshua J. Lawler; Denis White; Ronald P. Neilson; Andrew R. Blaustein

2006-01-01

Predicted changes in the global climate are likely to cause large shifts in the geographic ranges of many plant and animal species. To date, predictions of future range shifts have relied on a variety of modeling approaches with different levels of model accuracy. Using a common data set, we investigated the potential implications of alternative modeling approaches for...

Predictive Modeling of a Paradigm Mechanical Cooling Tower Model: II. Optimal Best-Estimate Results with Reduced Predicted Uncertainties

Directory of Open Access Journals (Sweden)

Ruixian Fang

2016-09-01

Full Text Available This work uses the adjoint sensitivity model of the counter-flow cooling tower derived in the accompanying PART I to obtain the expressions and relative numerical rankings of the sensitivities, to all model parameters, of the following model responses: (i outlet air temperature; (ii outlet water temperature; (iii outlet water mass flow rate; and (iv air outlet relative humidity. These sensitivities are subsequently used within the “predictive modeling for coupled multi-physics systems” (PM_CMPS methodology to obtain explicit formulas for the predicted optimal nominal values for the model responses and parameters, along with reduced predicted standard deviations for the predicted model parameters and responses. These explicit formulas embody the assimilation of experimental data and the “calibration” of the model’s parameters. The results presented in this work demonstrate that the PM_CMPS methodology reduces the predicted standard deviations to values that are smaller than either the computed or the experimentally measured ones, even for responses (e.g., the outlet water flow rate for which no measurements are available. These improvements stem from the global characteristics of the PM_CMPS methodology, which combines all of the available information simultaneously in phase-space, as opposed to combining it sequentially, as in current data assimilation procedures.

Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.

Science.gov (United States)

Marzano, Cristina; Ferrara, Michele; Mauro, Federica; Moroni, Fabio; Gorgoni, Maurizio; Tempesta, Daniela; Cipolli, Carlo; De Gennaro, Luigi

2011-05-04

Under the assumption that dream recall is a peculiar form of declarative memory, we have hypothesized that (1) the encoding of dream contents during sleep should share some electrophysiological mechanisms with the encoding of episodic memories of the awake brain and (2) recalling a dream(s) after awakening from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep should be associated with different brain oscillations. Here, we report that cortical brain oscillations of human sleep are predictive of successful dream recall. In particular, after morning awakening from REM sleep, a higher frontal 5-7 Hz (theta) activity was associated with successful dream recall. This finding mirrors the increase in frontal theta activity during successful encoding of episodic memories in wakefulness. Moreover, in keeping with the different EEG background, a different predictive relationship was found after awakening from stage 2 NREM sleep. Specifically, a lower 8-12 Hz (alpha) oscillatory activity of the right temporal area was associated with a successful dream recall. These findings provide the first evidence of univocal cortical electroencephalographic correlates of dream recall, suggesting that the neurophysiological mechanisms underlying the encoding and recall of episodic memories may remain the same across different states of consciousness.

Model predictive control classical, robust and stochastic

CERN Document Server

Kouvaritakis, Basil

2016-01-01

For the first time, a textbook that brings together classical predictive control with treatment of up-to-date robust and stochastic techniques. Model Predictive Control describes the development of tractable algorithms for uncertain, stochastic, constrained systems. The starting point is classical predictive control and the appropriate formulation of performance objectives and constraints to provide guarantees of closed-loop stability and performance. Moving on to robust predictive control, the text explains how similar guarantees may be obtained for cases in which the model describing the system dynamics is subject to additive disturbances and parametric uncertainties. Open- and closed-loop optimization are considered and the state of the art in computationally tractable methods based on uncertainty tubes presented for systems with additive model uncertainty. Finally, the tube framework is also applied to model predictive control problems involving hard or probabilistic constraints for the cases of multiplic...

Automatic detection of slow-wave sleep and REM-sleep stages using polysomnographic ECG signals

International Nuclear Information System (INIS)

Khemiri, S.; Aloui, K.; Naceur, M. S.

2011-01-01

We describe in this paper a new approach of classifying the different sleep stages only by focusing on the polysomnographic ECG signals. We show the pre-processing technique of the ECG signals. At the same time the identifcation and elimination of the different types of artifacts which contain the signal and its reconstruction are shown. The automatic classification of the slow-deep sleep and the rapid eye movement sleep called in this work REM-sleep consists in extracting physiological indicators that characterize these two sleep stages through the polysomnographic ECG signal. In other words, this classification is based on the analysis of the cardiac rhythm during a night's sleep.

Burden of proof for the illegal immissions as prerequisite of in rem removal claim

Directory of Open Access Journals (Sweden)

Knežević Marko

2013-01-01

Full Text Available The paper examines the question of the burden of proof for the facts that imply illegal immission as prerequisite of in rem removal claim. The approach is different to the standard doctrine and it is in according to the general rule of the burden of proof in litigation - so called modified norm theory. In the centre of the attention is distinction of so called constitutive and impeditive facts, and criteria for distinction. The implementation of modified norm theory regarding issue of this paper shows that primal distinguishing point is not suitable, so the other modification methods should be applied, in order to get the answer.

Prediction of the health effects of inhaled transuranium elements from experimental animal data

International Nuclear Information System (INIS)

Bair, W.J.; Thomas, J.M.

1976-01-01

Although animal experiments are conducted to obtain data that can be used to predict the consequences of exposure to alpha-emitting elements on human health, scientists have been hesitant to project the results of animal experiments to man. However, since a human data base does not exist for inhaled transuranics, the animal data cannot be overlooked. The paper describes the derivation of linear non-threshold response relationships for lung cancer in rats after inhalation of alpha-emitting transuranium elements. These relationships were used to calculate risk estimates, which were then compared with a value calculated from the incidence of lung cancer in humans who had been exposed to sources of radiation other than the transuranics. Both estimates were compared with the estimated cancer risk associated with the annual whole-body dose limit of 5 rems for occupational exposure. The rat data suggest that the risk from a working lifetime exposure of 15 rem/a to the lungs from transuranium elements may be 5 times the risk incurred with a whole-body exposure of 5 rem/a, while the human data suggest the risk may be less. Since the histological type of plutonium-induced lung cancer that occurs in experimental animals is rare in man, the use of animal data to estimate risks may be conservative. Risk estimates calculated directly from the results of experiments in which animals actually inhaled transuranic particles circumvent such controversial issues as 'hot particles'. (author)

Model predictive Controller for Mobile Robot

OpenAIRE

Alireza Rezaee

2017-01-01

This paper proposes a Model Predictive Controller (MPC) for control of a P2AT mobile robot. MPC refers to a group of controllers that employ a distinctly identical model of process to predict its future behavior over an extended prediction horizon. The design of a MPC is formulated as an optimal control problem. Then this problem is considered as linear quadratic equation (LQR) and is solved by making use of Ricatti equation. To show the effectiveness of the proposed method this controller is...

Deep Predictive Models in Interactive Music

OpenAIRE

Martin, Charles P.; Ellefsen, Kai Olav; Torresen, Jim

2018-01-01

Automatic music generation is a compelling task where much recent progress has been made with deep learning models. In this paper, we ask how these models can be integrated into interactive music systems; how can they encourage or enhance the music making of human users? Musical performance requires prediction to operate instruments, and perform in groups. We argue that predictive models could help interactive systems to understand their temporal context, and ensemble behaviour. Deep learning...

Risk prediction model: Statistical and artificial neural network approach

Science.gov (United States)

Paiman, Nuur Azreen; Hariri, Azian; Masood, Ibrahim

2017-04-01

Prediction models are increasingly gaining popularity and had been used in numerous areas of studies to complement and fulfilled clinical reasoning and decision making nowadays. The adoption of such models assist physician's decision making, individual's behavior, and consequently improve individual outcomes and the cost-effectiveness of care. The objective of this paper is to reviewed articles related to risk prediction model in order to understand the suitable approach, development and the validation process of risk prediction model. A qualitative review of the aims, methods and significant main outcomes of the nineteen published articles that developed risk prediction models from numerous fields were done. This paper also reviewed on how researchers develop and validate the risk prediction models based on statistical and artificial neural network approach. From the review done, some methodological recommendation in developing and validating the prediction model were highlighted. According to studies that had been done, artificial neural network approached in developing the prediction model were more accurate compared to statistical approach. However currently, only limited published literature discussed on which approach is more accurate for risk prediction model development.

Evaluation of CASP8 model quality predictions

KAUST Repository

Cozzetto, Domenico

2009-01-01

The model quality assessment problem consists in the a priori estimation of the overall and per-residue accuracy of protein structure predictions. Over the past years, a number of methods have been developed to address this issue and CASP established a prediction category to evaluate their performance in 2006. In 2008 the experiment was repeated and its results are reported here. Participants were invited to infer the correctness of the protein models submitted by the registered automatic servers. Estimates could apply to both whole models and individual amino acids. Groups involved in the tertiary structure prediction categories were also asked to assign local error estimates to each predicted residue in their own models and their results are also discussed here. The correlation between the predicted and observed correctness measures was the basis of the assessment of the results. We observe that consensus-based methods still perform significantly better than those accepting single models, similarly to what was concluded in the previous edition of the experiment. © 2009 WILEY-LISS, INC.

Predictive models of moth development

Science.gov (United States)

Degree-day models link ambient temperature to insect life-stages, making such models valuable tools in integrated pest management. These models increase management efficacy by predicting pest phenology. In Wisconsin, the top insect pest of cranberry production is the cranberry fruitworm, Acrobasis v...

Model Prediction Control For Water Management Using Adaptive Prediction Accuracy

NARCIS (Netherlands)

Tian, X.; Negenborn, R.R.; Van Overloop, P.J.A.T.M.; Mostert, E.

2014-01-01

In the field of operational water management, Model Predictive Control (MPC) has gained popularity owing to its versatility and flexibility. The MPC controller, which takes predictions, time delay and uncertainties into account, can be designed for multi-objective management problems and for

Abnormal metabolic network activity in REM sleep behavior disorder.

Science.gov (United States)

Holtbernd, Florian; Gagnon, Jean-François; Postuma, Ron B; Ma, Yilong; Tang, Chris C; Feigin, Andrew; Dhawan, Vijay; Vendette, Mélanie; Soucy, Jean-Paul; Eidelberg, David; Montplaisir, Jacques

2014-02-18

To determine whether the Parkinson disease-related covariance pattern (PDRP) expression is abnormally increased in idiopathic REM sleep behavior disorder (RBD) and whether increased baseline activity is associated with greater individual risk of subsequent phenoconversion. For this cohort study, we recruited 2 groups of RBD and control subjects. Cohort 1 comprised 10 subjects with RBD (63.5 ± 9.4 years old) and 10 healthy volunteers (62.7 ± 8.6 years old) who underwent resting-state metabolic brain imaging with (18)F-fluorodeoxyglucose PET. Cohort 2 comprised 17 subjects with RBD (68.9 ± 4.8 years old) and 17 healthy volunteers (66.6 ± 6.0 years old) who underwent resting brain perfusion imaging with ethylcysteinate dimer SPECT. The latter group was followed clinically for 4.6 ± 2.5 years by investigators blinded to the imaging results. PDRP expression was measured in both RBD groups and compared with corresponding control values. PDRP expression was elevated in both groups of subjects with RBD (cohort 1: p abnormalities in subjects with idiopathic RBD are associated with a greater likelihood of subsequent phenoconversion to a progressive neurodegenerative syndrome.

Autonomic Function in Neurodegenerative Diseases

DEFF Research Database (Denmark)

Sørensen, Gertrud Laura; Jennum, Poul Jørgen

2013-01-01

areas, which is consistent with the Braak hypothesis. In the narcolepsy patients, it was shown that a reduced HRR to arousals was primarily predicted by hypocretin deficiency in both rapid-eye-movement (REM) and non-REM sleep, independent of cataplexy and other factors. The results confirm...... that hypocretin deficiency affects the autonomic nervous system of patients with narcolepsy and that the hypocretin system is important for proper heart rate modulation at rest.Furthermore, it was shown that hypocretin deficiency and cataplexy are associated with signs of destabilized sleep-wake and REM sleep...... control, indicating that the disorder may serve as a human model for the sleep-wake and REM sleep flip-flop switches. The increased frequency of transitions may cause increased sympathetic activity during sleep and thereby increased heart rate, or the increased heart rate could be caused by decreased...

Predicting water main failures using Bayesian model averaging and survival modelling approach

International Nuclear Information System (INIS)

Kabir, Golam; Tesfamariam, Solomon; Sadiq, Rehan

2015-01-01

To develop an effective preventive or proactive repair and replacement action plan, water utilities often rely on water main failure prediction models. However, in predicting the failure of water mains, uncertainty is inherent regardless of the quality and quantity of data used in the model. To improve the understanding of water main failure, a Bayesian framework is developed for predicting the failure of water mains considering uncertainties. In this study, Bayesian model averaging method (BMA) is presented to identify the influential pipe-dependent and time-dependent covariates considering model uncertainties whereas Bayesian Weibull Proportional Hazard Model (BWPHM) is applied to develop the survival curves and to predict the failure rates of water mains. To accredit the proposed framework, it is implemented to predict the failure of cast iron (CI) and ductile iron (DI) pipes of the water distribution network of the City of Calgary, Alberta, Canada. Results indicate that the predicted 95% uncertainty bounds of the proposed BWPHMs capture effectively the observed breaks for both CI and DI water mains. Moreover, the performance of the proposed BWPHMs are better compare to the Cox-Proportional Hazard Model (Cox-PHM) for considering Weibull distribution for the baseline hazard function and model uncertainties. - Highlights: • Prioritize rehabilitation and replacements (R/R) strategies of water mains. • Consider the uncertainties for the failure prediction. • Improve the prediction capability of the water mains failure models. • Identify the influential and appropriate covariates for different models. • Determine the effects of the covariates on failure

Testing the predictive power of nuclear mass models

International Nuclear Information System (INIS)

Mendoza-Temis, J.; Morales, I.; Barea, J.; Frank, A.; Hirsch, J.G.; Vieyra, J.C. Lopez; Van Isacker, P.; Velazquez, V.

2008-01-01

A number of tests are introduced which probe the ability of nuclear mass models to extrapolate. Three models are analyzed in detail: the liquid drop model, the liquid drop model plus empirical shell corrections and the Duflo-Zuker mass formula. If predicted nuclei are close to the fitted ones, average errors in predicted and fitted masses are similar. However, the challenge of predicting nuclear masses in a region stabilized by shell effects (e.g., the lead region) is far more difficult. The Duflo-Zuker mass formula emerges as a powerful predictive tool

Comparison of Prediction-Error-Modelling Criteria

DEFF Research Database (Denmark)

Jørgensen, John Bagterp; Jørgensen, Sten Bay

2007-01-01

Single and multi-step prediction-error-methods based on the maximum likelihood and least squares criteria are compared. The prediction-error methods studied are based on predictions using the Kalman filter and Kalman predictors for a linear discrete-time stochastic state space model, which is a r...

Foundation Settlement Prediction Based on a Novel NGM Model

Directory of Open Access Journals (Sweden)

Peng-Yu Chen

2014-01-01

Full Text Available Prediction of foundation or subgrade settlement is very important during engineering construction. According to the fact that there are lots of settlement-time sequences with a nonhomogeneous index trend, a novel grey forecasting model called NGM (1,1,k,c model is proposed in this paper. With an optimized whitenization differential equation, the proposed NGM (1,1,k,c model has the property of white exponential law coincidence and can predict a pure nonhomogeneous index sequence precisely. We used two case studies to verify the predictive effect of NGM (1,1,k,c model for settlement prediction. The results show that this model can achieve excellent prediction accuracy; thus, the model is quite suitable for simulation and prediction of approximate nonhomogeneous index sequence and has excellent application value in settlement prediction.

Electrostatic ion thrusters - towards predictive modeling

Energy Technology Data Exchange (ETDEWEB)

Kalentev, O.; Matyash, K.; Duras, J.; Lueskow, K.F.; Schneider, R. [Ernst-Moritz-Arndt Universitaet Greifswald, D-17489 (Germany); Koch, N. [Technische Hochschule Nuernberg Georg Simon Ohm, Kesslerplatz 12, D-90489 Nuernberg (Germany); Schirra, M. [Thales Electronic Systems GmbH, Soeflinger Strasse 100, D-89077 Ulm (Germany)

2014-02-15

The development of electrostatic ion thrusters so far has mainly been based on empirical and qualitative know-how, and on evolutionary iteration steps. This resulted in considerable effort regarding prototype design, construction and testing and therefore in significant development and qualification costs and high time demands. For future developments it is anticipated to implement simulation tools which allow for quantitative prediction of ion thruster performance, long-term behavior and space craft interaction prior to hardware design and construction. Based on integrated numerical models combining self-consistent kinetic plasma models with plasma-wall interaction modules a new quality in the description of electrostatic thrusters can be reached. These open the perspective for predictive modeling in this field. This paper reviews the application of a set of predictive numerical modeling tools on an ion thruster model of the HEMP-T (High Efficiency Multi-stage Plasma Thruster) type patented by Thales Electron Devices GmbH. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Predictive validation of an influenza spread model.

Directory of Open Access Journals (Sweden)

Ayaz Hyder

Full Text Available BACKGROUND: Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. METHODS AND FINDINGS: We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998-1999. Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type. Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. CONCLUSIONS: Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve

Predictive Validation of an Influenza Spread Model

Science.gov (United States)

Hyder, Ayaz; Buckeridge, David L.; Leung, Brian

2013-01-01

Background Modeling plays a critical role in mitigating impacts of seasonal influenza epidemics. Complex simulation models are currently at the forefront of evaluating optimal mitigation strategies at multiple scales and levels of organization. Given their evaluative role, these models remain limited in their ability to predict and forecast future epidemics leading some researchers and public-health practitioners to question their usefulness. The objective of this study is to evaluate the predictive ability of an existing complex simulation model of influenza spread. Methods and Findings We used extensive data on past epidemics to demonstrate the process of predictive validation. This involved generalizing an individual-based model for influenza spread and fitting it to laboratory-confirmed influenza infection data from a single observed epidemic (1998–1999). Next, we used the fitted model and modified two of its parameters based on data on real-world perturbations (vaccination coverage by age group and strain type). Simulating epidemics under these changes allowed us to estimate the deviation/error between the expected epidemic curve under perturbation and observed epidemics taking place from 1999 to 2006. Our model was able to forecast absolute intensity and epidemic peak week several weeks earlier with reasonable reliability and depended on the method of forecasting-static or dynamic. Conclusions Good predictive ability of influenza epidemics is critical for implementing mitigation strategies in an effective and timely manner. Through the process of predictive validation applied to a current complex simulation model of influenza spread, we provided users of the model (e.g. public-health officials and policy-makers) with quantitative metrics and practical recommendations on mitigating impacts of seasonal influenza epidemics. This methodology may be applied to other models of communicable infectious diseases to test and potentially improve their predictive

Integrating geophysics and hydrology for reducing the uncertainty of groundwater model predictions and improved prediction performance

DEFF Research Database (Denmark)

Christensen, Nikolaj Kruse; Christensen, Steen; Ferre, Ty

the integration of geophysical data in the construction of a groundwater model increases the prediction performance. We suggest that modelers should perform a hydrogeophysical “test-bench” analysis of the likely value of geophysics data for improving groundwater model prediction performance before actually...... and the resulting predictions can be compared with predictions from the ‘true’ model. By performing this analysis we expect to give the modeler insight into how the uncertainty of model-based prediction can be reduced.......A major purpose of groundwater modeling is to help decision-makers in efforts to manage the natural environment. Increasingly, it is recognized that both the predictions of interest and their associated uncertainties should be quantified to support robust decision making. In particular, decision...

Predictive Surface Complexation Modeling

Energy Technology Data Exchange (ETDEWEB)

Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences

2016-11-29

Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO₂ and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

NOx PREDICTION FOR FBC BOILERS USING EMPIRICAL MODELS

Directory of Open Access Journals (Sweden)

Jiří Štefanica

2014-02-01

Full Text Available Reliable prediction of NOx emissions can provide useful information for boiler design and fuel selection. Recently used kinetic prediction models for FBC boilers are overly complex and require large computing capacity. Even so, there are many uncertainties in the case of FBC boilers. An empirical modeling approach for NOx prediction has been used exclusively for PCC boilers. No reference is available for modifying this method for FBC conditions. This paper presents possible advantages of empirical modeling based prediction of NOx emissions for FBC boilers, together with a discussion of its limitations. Empirical models are reviewed, and are applied to operation data from FBC boilers used for combusting Czech lignite coal or coal-biomass mixtures. Modifications to the model are proposed in accordance with theoretical knowledge and prediction accuracy.

Prediction of pipeline corrosion rate based on grey Markov models

International Nuclear Information System (INIS)

Chen Yonghong; Zhang Dafa; Peng Guichu; Wang Yuemin

2009-01-01

Based on the model that combined by grey model and Markov model, the prediction of corrosion rate of nuclear power pipeline was studied. Works were done to improve the grey model, and the optimization unbiased grey model was obtained. This new model was used to predict the tendency of corrosion rate, and the Markov model was used to predict the residual errors. In order to improve the prediction precision, rolling operation method was used in these prediction processes. The results indicate that the improvement to the grey model is effective and the prediction precision of the new model combined by the optimization unbiased grey model and Markov model is better, and the use of rolling operation method may improve the prediction precision further. (authors)

Sweat loss prediction using a multi-model approach.

Science.gov (United States)

Xu, Xiaojiang; Santee, William R

2011-07-01

A new multi-model approach (MMA) for sweat loss prediction is proposed to improve prediction accuracy. MMA was computed as the average of sweat loss predicted by two existing thermoregulation models: i.e., the rational model SCENARIO and the empirical model Heat Strain Decision Aid (HSDA). Three independent physiological datasets, a total of 44 trials, were used to compare predictions by MMA, SCENARIO, and HSDA. The observed sweat losses were collected under different combinations of uniform ensembles, environmental conditions (15-40°C, RH 25-75%), and exercise intensities (250-600 W). Root mean square deviation (RMSD), residual plots, and paired t tests were used to compare predictions with observations. Overall, MMA reduced RMSD by 30-39% in comparison with either SCENARIO or HSDA, and increased the prediction accuracy to 66% from 34% or 55%. Of the MMA predictions, 70% fell within the range of mean observed value ± SD, while only 43% of SCENARIO and 50% of HSDA predictions fell within the same range. Paired t tests showed that differences between observations and MMA predictions were not significant, but differences between observations and SCENARIO or HSDA predictions were significantly different for two datasets. Thus, MMA predicted sweat loss more accurately than either of the two single models for the three datasets used. Future work will be to evaluate MMA using additional physiological data to expand the scope of populations and conditions.

Psychoanalytic dream theory and recent neurobiological findings about REM sleep.

Science.gov (United States)

Wasserman, M D

1984-01-01

I have reviewed Hobson and McCarley's activation-synthesis hypothesis of dreaming which attempts to show that the instigation and certain formal aspects of dreaming are physiologically determined by a brainstem neuronal mechanism, their reasons for suggesting major revisions in psychoanalytic dream theory, and neurophysiological data that are inconsistent with their hypothesis. I then discussed the concept of mind-body isomorphism pointing out that they use this concept inconsistently, that despite their denials they regularly view physiology as primary and psychological processes as secondary, and that they frequently make the error of mixing the languages of physiology and psychology in their explanatory statements. Finally, in order to evaluate Hobson and McCarley's claim that their findings require revision of psychoanalytic dream theory, I examined their discussions of chase dreams, flying dreams, sexual dreams, the formal characteristics of dreams, the forgetting of dreams, and the instigation of dreams. I concluded that although their fascinating physiological findings may be central to understanding the neurobiology of REM sleep, they do not alter the meaning and interpretation of dreams gleaned through psychoanalytic study.

Finding Furfural Hydrogenation Catalysts via Predictive Modelling

Science.gov (United States)

Strassberger, Zea; Mooijman, Maurice; Ruijter, Eelco; Alberts, Albert H; Maldonado, Ana G; Orru, Romano V A; Rothenberg, Gadi

2010-01-01

Abstract We combine multicomponent reactions, catalytic performance studies and predictive modelling to find transfer hydrogenation catalysts. An initial set of 18 ruthenium-carbene complexes were synthesized and screened in the transfer hydrogenation of furfural to furfurol with isopropyl alcohol complexes gave varied yields, from 62% up to >99.9%, with no obvious structure/activity correlations. Control experiments proved that the carbene ligand remains coordinated to the ruthenium centre throughout the reaction. Deuterium-labelling studies showed a secondary isotope effect (kH:kD=1.5). Further mechanistic studies showed that this transfer hydrogenation follows the so-called monohydride pathway. Using these data, we built a predictive model for 13 of the catalysts, based on 2D and 3D molecular descriptors. We tested and validated the model using the remaining five catalysts (cross-validation, R2=0.913). Then, with this model, the conversion and selectivity were predicted for four completely new ruthenium-carbene complexes. These four catalysts were then synthesized and tested. The results were within 3% of the model’s predictions, demonstrating the validity and value of predictive modelling in catalyst optimization. PMID:23193388

Alcator C-Mod predictive modeling

International Nuclear Information System (INIS)

Pankin, Alexei; Bateman, Glenn; Kritz, Arnold; Greenwald, Martin; Snipes, Joseph; Fredian, Thomas

2001-01-01

Predictive simulations for the Alcator C-mod tokamak [I. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] are carried out using the BALDUR integrated modeling code [C. E. Singer et al., Comput. Phys. Commun. 49, 275 (1988)]. The results are obtained for temperature and density profiles using the Multi-Mode transport model [G. Bateman et al., Phys. Plasmas 5, 1793 (1998)] as well as the mixed-Bohm/gyro-Bohm transport model [M. Erba et al., Plasma Phys. Controlled Fusion 39, 261 (1997)]. The simulated discharges are characterized by very high plasma density in both low and high modes of confinement. The predicted profiles for each of the transport models match the experimental data about equally well in spite of the fact that the two models have different dimensionless scalings. Average relative rms deviations are less than 8% for the electron density profiles and 16% for the electron and ion temperature profiles

Clinical Predictive Modeling Development and Deployment through FHIR Web Services.

Science.gov (United States)

Khalilia, Mohammed; Choi, Myung; Henderson, Amelia; Iyengar, Sneha; Braunstein, Mark; Sun, Jimeng

2015-01-01

Clinical predictive modeling involves two challenging tasks: model development and model deployment. In this paper we demonstrate a software architecture for developing and deploying clinical predictive models using web services via the Health Level 7 (HL7) Fast Healthcare Interoperability Resources (FHIR) standard. The services enable model development using electronic health records (EHRs) stored in OMOP CDM databases and model deployment for scoring individual patients through FHIR resources. The MIMIC2 ICU dataset and a synthetic outpatient dataset were transformed into OMOP CDM databases for predictive model development. The resulting predictive models are deployed as FHIR resources, which receive requests of patient information, perform prediction against the deployed predictive model and respond with prediction scores. To assess the practicality of this approach we evaluated the response and prediction time of the FHIR modeling web services. We found the system to be reasonably fast with one second total response time per patient prediction.

Predictive Modelling of Heavy Metals in Urban Lakes

OpenAIRE

Lindström, Martin

2000-01-01

Heavy metals are well-known environmental pollutants. In this thesis predictive models for heavy metals in urban lakes are discussed and new models presented. The base of predictive modelling is empirical data from field investigations of many ecosystems covering a wide range of ecosystem characteristics. Predictive models focus on the variabilities among lakes and processes controlling the major metal fluxes. Sediment and water data for this study were collected from ten small lakes in the ...

Stage-specific predictive models for breast cancer survivability.

Science.gov (United States)

Kate, Rohit J; Nadig, Ramya

2017-01-01

Survivability rates vary widely among various stages of breast cancer. Although machine learning models built in past to predict breast cancer survivability were given stage as one of the features, they were not trained or evaluated separately for each stage. To investigate whether there are differences in performance of machine learning models trained and evaluated across different stages for predicting breast cancer survivability. Using three different machine learning methods we built models to predict breast cancer survivability separately for each stage and compared them with the traditional joint models built for all the stages. We also evaluated the models separately for each stage and together for all the stages. Our results show that the most suitable model to predict survivability for a specific stage is the model trained for that particular stage. In our experiments, using additional examples of other stages during training did not help, in fact, it made it worse in some cases. The most important features for predicting survivability were also found to be different for different stages. By evaluating the models separately on different stages we found that the performance widely varied across them. We also demonstrate that evaluating predictive models for survivability on all the stages together, as was done in the past, is misleading because it overestimates performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Impact of modellers' decisions on hydrological a priori predictions

Science.gov (United States)

Holländer, H. M.; Bormann, H.; Blume, T.; Buytaert, W.; Chirico, G. B.; Exbrayat, J.-F.; Gustafsson, D.; Hölzel, H.; Krauße, T.; Kraft, P.; Stoll, S.; Blöschl, G.; Flühler, H.

2014-06-01

In practice, the catchment hydrologist is often confronted with the task of predicting discharge without having the needed records for calibration. Here, we report the discharge predictions of 10 modellers - using the model of their choice - for the man-made Chicken Creek catchment (6 ha, northeast Germany, Gerwin et al., 2009b) and we analyse how well they improved their prediction in three steps based on adding information prior to each following step. The modellers predicted the catchment's hydrological response in its initial phase without having access to the observed records. They used conceptually different physically based models and their modelling experience differed largely. Hence, they encountered two problems: (i) to simulate discharge for an ungauged catchment and (ii) using models that were developed for catchments, which are not in a state of landscape transformation. The prediction exercise was organized in three steps: (1) for the first prediction the modellers received a basic data set describing the catchment to a degree somewhat more complete than usually available for a priori predictions of ungauged catchments; they did not obtain information on stream flow, soil moisture, nor groundwater response and had therefore to guess the initial conditions; (2) before the second prediction they inspected the catchment on-site and discussed their first prediction attempt; (3) for their third prediction they were offered additional data by charging them pro forma with the costs for obtaining this additional information. Holländer et al. (2009) discussed the range of predictions obtained in step (1). Here, we detail the modeller's assumptions and decisions in accounting for the various processes. We document the prediction progress as well as the learning process resulting from the availability of added information. For the second and third steps, the progress in prediction quality is evaluated in relation to individual modelling experience and costs of

A multivariate model for predicting segmental body composition.

Science.gov (United States)

Tian, Simiao; Mioche, Laurence; Denis, Jean-Baptiste; Morio, Béatrice

2013-12-01

The aims of the present study were to propose a multivariate model for predicting simultaneously body, trunk and appendicular fat and lean masses from easily measured variables and to compare its predictive capacity with that of the available univariate models that predict body fat percentage (BF%). The dual-energy X-ray absorptiometry (DXA) dataset (52% men and 48% women) with White, Black and Hispanic ethnicities (1999-2004, National Health and Nutrition Examination Survey) was randomly divided into three sub-datasets: a training dataset (TRD), a test dataset (TED); a validation dataset (VAD), comprising 3835, 1917 and 1917 subjects. For each sex, several multivariate prediction models were fitted from the TRD using age, weight, height and possibly waist circumference. The most accurate model was selected from the TED and then applied to the VAD and a French DXA dataset (French DB) (526 men and 529 women) to assess the prediction accuracy in comparison with that of five published univariate models, for which adjusted formulas were re-estimated using the TRD. Waist circumference was found to improve the prediction accuracy, especially in men. For BF%, the standard error of prediction (SEP) values were 3.26 (3.75) % for men and 3.47 (3.95)% for women in the VAD (French DB), as good as those of the adjusted univariate models. Moreover, the SEP values for the prediction of body and appendicular lean masses ranged from 1.39 to 2.75 kg for both the sexes. The prediction accuracy was best for age < 65 years, BMI < 30 kg/m2 and the Hispanic ethnicity. The application of our multivariate model to large populations could be useful to address various public health issues.

Two stage neural network modelling for robust model predictive control.

Science.gov (United States)

Patan, Krzysztof

2018-01-01

The paper proposes a novel robust model predictive control scheme realized by means of artificial neural networks. The neural networks are used twofold: to design the so-called fundamental model of a plant and to catch uncertainty associated with the plant model. In order to simplify the optimization process carried out within the framework of predictive control an instantaneous linearization is applied which renders it possible to define the optimization problem in the form of constrained quadratic programming. Stability of the proposed control system is also investigated by showing that a cost function is monotonically decreasing with respect to time. Derived robust model predictive control is tested and validated on the example of a pneumatic servomechanism working at different operating regimes. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Hybrid Corporate Performance Prediction Model Considering Technical Capability

Directory of Open Access Journals (Sweden)

Joonhyuck Lee

2016-07-01

Full Text Available Many studies have tried to predict corporate performance and stock prices to enhance investment profitability using qualitative approaches such as the Delphi method. However, developments in data processing technology and machine-learning algorithms have resulted in efforts to develop quantitative prediction models in various managerial subject areas. We propose a quantitative corporate performance prediction model that applies the support vector regression (SVR algorithm to solve the problem of the overfitting of training data and can be applied to regression problems. The proposed model optimizes the SVR training parameters based on the training data, using the genetic algorithm to achieve sustainable predictability in changeable markets and managerial environments. Technology-intensive companies represent an increasing share of the total economy. The performance and stock prices of these companies are affected by their financial standing and their technological capabilities. Therefore, we apply both financial indicators and technical indicators to establish the proposed prediction model. Here, we use time series data, including financial, patent, and corporate performance information of 44 electronic and IT companies. Then, we predict the performance of these companies as an empirical verification of the prediction performance of the proposed model.

Dynamic Simulation of Human Gait Model With Predictive Capability.

Science.gov (United States)

Sun, Jinming; Wu, Shaoli; Voglewede, Philip A

2018-03-01

In this paper, it is proposed that the central nervous system (CNS) controls human gait using a predictive control approach in conjunction with classical feedback control instead of exclusive classical feedback control theory that controls based on past error. To validate this proposition, a dynamic model of human gait is developed using a novel predictive approach to investigate the principles of the CNS. The model developed includes two parts: a plant model that represents the dynamics of human gait and a controller that represents the CNS. The plant model is a seven-segment, six-joint model that has nine degrees-of-freedom (DOF). The plant model is validated using data collected from able-bodied human subjects. The proposed controller utilizes model predictive control (MPC). MPC uses an internal model to predict the output in advance, compare the predicted output to the reference, and optimize the control input so that the predicted error is minimal. To decrease the complexity of the model, two joints are controlled using a proportional-derivative (PD) controller. The developed predictive human gait model is validated by simulating able-bodied human gait. The simulation results show that the developed model is able to simulate the kinematic output close to experimental data.

Massive Predictive Modeling using Oracle R Enterprise

CERN Multimedia

CERN. Geneva

2014-01-01

R is fast becoming the lingua franca for analyzing data via statistics, visualization, and predictive analytics. For enterprise-scale data, R users have three main concerns: scalability, performance, and production deployment. Oracle's R-based technologies - Oracle R Distribution, Oracle R Enterprise, Oracle R Connector for Hadoop, and the R package ROracle - address these concerns. In this talk, we introduce Oracle's R technologies, highlighting how each enables R users to achieve scalability and performance while making production deployment of R results a natural outcome of the data analyst/scientist efforts. The focus then turns to Oracle R Enterprise with code examples using the transparency layer and embedded R execution, targeting massive predictive modeling. One goal behind massive predictive modeling is to build models per entity, such as customers, zip codes, simulations, in an effort to understand behavior and tailor predictions at the entity level. Predictions...

Prediction of residential radon exposure of the whole Swiss population: comparison of model-based predictions with measurement-based predictions.

Science.gov (United States)

Hauri, D D; Huss, A; Zimmermann, F; Kuehni, C E; Röösli, M

2013-10-01

Radon plays an important role for human exposure to natural sources of ionizing radiation. The aim of this article is to compare two approaches to estimate mean radon exposure in the Swiss population: model-based predictions at individual level and measurement-based predictions based on measurements aggregated at municipality level. A nationwide model was used to predict radon levels in each household and for each individual based on the corresponding tectonic unit, building age, building type, soil texture, degree of urbanization, and floor. Measurement-based predictions were carried out within a health impact assessment on residential radon and lung cancer. Mean measured radon levels were corrected for the average floor distribution and weighted with population size of each municipality. Model-based predictions yielded a mean radon exposure of the Swiss population of 84.1 Bq/m(3) . Measurement-based predictions yielded an average exposure of 78 Bq/m(3) . This study demonstrates that the model- and the measurement-based predictions provided similar results. The advantage of the measurement-based approach is its simplicity, which is sufficient for assessing exposure distribution in a population. The model-based approach allows predicting radon levels at specific sites, which is needed in an epidemiological study, and the results do not depend on how the measurement sites have been selected. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A burnout prediction model based around char morphology

Energy Technology Data Exchange (ETDEWEB)

T. Wu; E. Lester; M. Cloke [University of Nottingham, Nottingham (United Kingdom). Nottingham Energy and Fuel Centre

2005-07-01

Poor burnout in a coal-fired power plant has marked penalties in the form of reduced energy efficiency and elevated waste material that can not be utilized. The prediction of coal combustion behaviour in a furnace is of great significance in providing valuable information not only for process optimization but also for coal buyers in the international market. Coal combustion models have been developed that can make predictions about burnout behaviour and burnout potential. Most of these kinetic models require standard parameters such as volatile content, particle size and assumed char porosity in order to make a burnout prediction. This paper presents a new model called the Char Burnout Model (ChB) that also uses detailed information about char morphology in its prediction. The model can use data input from one of two sources. Both sources are derived from image analysis techniques. The first from individual analysis and characterization of real char types using an automated program. The second from predicted char types based on data collected during the automated image analysis of coal particles. Modelling results were compared with a different carbon burnout kinetic model and burnout data from re-firing the chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen across several residence times. An improved agreement between ChB model and DTF experimental data proved that the inclusion of char morphology in combustion models can improve model predictions. 27 refs., 4 figs., 4 tabs.

Clinical Prediction Models for Cardiovascular Disease: Tufts Predictive Analytics and Comparative Effectiveness Clinical Prediction Model Database.

Science.gov (United States)

Wessler, Benjamin S; Lai Yh, Lana; Kramer, Whitney; Cangelosi, Michael; Raman, Gowri; Lutz, Jennifer S; Kent, David M

2015-07-01

Clinical prediction models (CPMs) estimate the probability of clinical outcomes and hold the potential to improve decision making and individualize care. For patients with cardiovascular disease, there are numerous CPMs available although the extent of this literature is not well described. We conducted a systematic review for articles containing CPMs for cardiovascular disease published between January 1990 and May 2012. Cardiovascular disease includes coronary heart disease, heart failure, arrhythmias, stroke, venous thromboembolism, and peripheral vascular disease. We created a novel database and characterized CPMs based on the stage of development, population under study, performance, covariates, and predicted outcomes. There are 796 models included in this database. The number of CPMs published each year is increasing steadily over time. Seven hundred seventeen (90%) are de novo CPMs, 21 (3%) are CPM recalibrations, and 58 (7%) are CPM adaptations. This database contains CPMs for 31 index conditions, including 215 CPMs for patients with coronary artery disease, 168 CPMs for population samples, and 79 models for patients with heart failure. There are 77 distinct index/outcome pairings. Of the de novo models in this database, 450 (63%) report a c-statistic and 259 (36%) report some information on calibration. There is an abundance of CPMs available for a wide assortment of cardiovascular disease conditions, with substantial redundancy in the literature. The comparative performance of these models, the consistency of effects and risk estimates across models and the actual and potential clinical impact of this body of literature is poorly understood. © 2015 American Heart Association, Inc.

Prediction of resource volumes at untested locations using simple local prediction models

Science.gov (United States)

Attanasi, E.D.; Coburn, T.C.; Freeman, P.A.

2006-01-01

This paper shows how local spatial nonparametric prediction models can be applied to estimate volumes of recoverable gas resources at individual undrilled sites, at multiple sites on a regional scale, and to compute confidence bounds for regional volumes based on the distribution of those estimates. An approach that combines cross-validation, the jackknife, and bootstrap procedures is used to accomplish this task. Simulation experiments show that cross-validation can be applied beneficially to select an appropriate prediction model. The cross-validation procedure worked well for a wide range of different states of nature and levels of information. Jackknife procedures are used to compute individual prediction estimation errors at undrilled locations. The jackknife replicates also are used with a bootstrap resampling procedure to compute confidence bounds for the total volume. The method was applied to data (partitioned into a training set and target set) from the Devonian Antrim Shale continuous-type gas play in the Michigan Basin in Otsego County, Michigan. The analysis showed that the model estimate of total recoverable volumes at prediction sites is within 4 percent of the total observed volume. The model predictions also provide frequency distributions of the cell volumes at the production unit scale. Such distributions are the basis for subsequent economic analyses. ?? Springer Science+Business Media, LLC 2007.

A burnout prediction model based around char morphology

Energy Technology Data Exchange (ETDEWEB)

Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

2006-05-15

Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

Comparative Study of Bancruptcy Prediction Models

Directory of Open Access Journals (Sweden)

Isye Arieshanti

2013-09-01

Full Text Available Early indication of bancruptcy is important for a company. If companies aware of  potency of their bancruptcy, they can take a preventive action to anticipate the bancruptcy. In order to detect the potency of a bancruptcy, a company can utilize a a model of bancruptcy prediction. The prediction model can be built using a machine learning methods. However, the choice of machine learning methods should be performed carefully. Because the suitability of a model depends on the problem specifically. Therefore, in this paper we perform a comparative study of several machine leaning methods for bancruptcy prediction. According to the comparative study, the performance of several models that based on machine learning methods (k-NN, fuzzy k-NN, SVM, Bagging Nearest Neighbour SVM, Multilayer Perceptron(MLP, Hybrid of MLP + Multiple Linear Regression, it can be showed that fuzzy k-NN method achieve the best performance with accuracy 77.5%

Restorative effects of curcumin on sleep-deprivation induced memory impairments and structural changes of the hippocampus in a rat model.

Science.gov (United States)

Noorafshan, Ali; Karimi, Fatemeh; Kamali, Ali-Mohammad; Karbalay-Doust, Saied; Nami, Mohammad

2017-11-15

The present study examined the consequences of rapid eye-movement sleep-deprivation (REM-SD) with or without curcumin treatment. The outcome measures comprised quantitative features in the three-dimensional reconstruction (3DR) CA1 and dentate gyrus in experimental and control animals using stereological procedures. Male rats were arbitrarily assigned to nine groups based on the intervention and treatment administered including: 1-cage control+distilled water, 2-cage control+curcumin (100mg/kg/day), 3-cage control+olive oil, 4-REM-SD+distilled water, 5-REM-SD+curcumin, 6-REM-SD+olive oil, 7-grid-floor control+distilled water, 8-grid-floor control+curcumin, and 9-grid-floor control+olive oil. Animals in the latter three groups were placed on wire-mesh grids in the sleep-deprivation box. REM-SD was induced by an apparatus comprising a water tank and multiple platforms. After a period of 21days, rats were submitted to the novel object-recognition task. Later, their brains were excised and evaluated using stereological methods. Our results indicated a respective 29% and 31% reduction in the total volume of CA1, and dentate gyrus in REM-SD+distilled water group as compared to the grid-floor control+distilled water group (pcurcumin compared to the REM-SD+distilled water group. This suggests the potential neuro-restorative effects of curcumin in our model. Copyright © 2017 Elsevier Inc. All rights reserved.

A grey NGM(1,1, k) self-memory coupling prediction model for energy consumption prediction.

Science.gov (United States)

Guo, Xiaojun; Liu, Sifeng; Wu, Lifeng; Tang, Lingling

2014-01-01

Energy consumption prediction is an important issue for governments, energy sector investors, and other related corporations. Although there are several prediction techniques, selection of the most appropriate technique is of vital importance. As for the approximate nonhomogeneous exponential data sequence often emerging in the energy system, a novel grey NGM(1,1, k) self-memory coupling prediction model is put forward in order to promote the predictive performance. It achieves organic integration of the self-memory principle of dynamic system and grey NGM(1,1, k) model. The traditional grey model's weakness as being sensitive to initial value can be overcome by the self-memory principle. In this study, total energy, coal, and electricity consumption of China is adopted for demonstration by using the proposed coupling prediction technique. The results show the superiority of NGM(1,1, k) self-memory coupling prediction model when compared with the results from the literature. Its excellent prediction performance lies in that the proposed coupling model can take full advantage of the systematic multitime historical data and catch the stochastic fluctuation tendency. This work also makes a significant contribution to the enrichment of grey prediction theory and the extension of its application span.

Risk predictive modelling for diabetes and cardiovascular disease.

Science.gov (United States)

Kengne, Andre Pascal; Masconi, Katya; Mbanya, Vivian Nchanchou; Lekoubou, Alain; Echouffo-Tcheugui, Justin Basile; Matsha, Tandi E

2014-02-01

Absolute risk models or clinical prediction models have been incorporated in guidelines, and are increasingly advocated as tools to assist risk stratification and guide prevention and treatments decisions relating to common health conditions such as cardiovascular disease (CVD) and diabetes mellitus. We have reviewed the historical development and principles of prediction research, including their statistical underpinning, as well as implications for routine practice, with a focus on predictive modelling for CVD and diabetes. Predictive modelling for CVD risk, which has developed over the last five decades, has been largely influenced by the Framingham Heart Study investigators, while it is only ∼20 years ago that similar efforts were started in the field of diabetes. Identification of predictive factors is an important preliminary step which provides the knowledge base on potential predictors to be tested for inclusion during the statistical derivation of the final model. The derived models must then be tested both on the development sample (internal validation) and on other populations in different settings (external validation). Updating procedures (e.g. recalibration) should be used to improve the performance of models that fail the tests of external validation. Ultimately, the effect of introducing validated models in routine practice on the process and outcomes of care as well as its cost-effectiveness should be tested in impact studies before wide dissemination of models beyond the research context. Several predictions models have been developed for CVD or diabetes, but very few have been externally validated or tested in impact studies, and their comparative performance has yet to be fully assessed. A shift of focus from developing new CVD or diabetes prediction models to validating the existing ones will improve their adoption in routine practice.

Model-based uncertainty in species range prediction

DEFF Research Database (Denmark)

Pearson, R. G.; Thuiller, Wilfried; Bastos Araujo, Miguel

2006-01-01

Aim Many attempts to predict the potential range of species rely on environmental niche (or 'bioclimate envelope') modelling, yet the effects of using different niche-based methodologies require further investigation. Here we investigate the impact that the choice of model can have on predictions...

Survival prediction model for postoperative hepatocellular carcinoma patients.

Science.gov (United States)

Ren, Zhihui; He, Shasha; Fan, Xiaotang; He, Fangping; Sang, Wei; Bao, Yongxing; Ren, Weixin; Zhao, Jinming; Ji, Xuewen; Wen, Hao

2017-09-01

This study is to establish a predictive index (PI) model of 5-year survival rate for patients with hepatocellular carcinoma (HCC) after radical resection and to evaluate its prediction sensitivity, specificity, and accuracy.Patients underwent HCC surgical resection were enrolled and randomly divided into prediction model group (101 patients) and model evaluation group (100 patients). Cox regression model was used for univariate and multivariate survival analysis. A PI model was established based on multivariate analysis and receiver operating characteristic (ROC) curve was drawn accordingly. The area under ROC (AUROC) and PI cutoff value was identified.Multiple Cox regression analysis of prediction model group showed that neutrophil to lymphocyte ratio, histological grade, microvascular invasion, positive resection margin, number of tumor, and postoperative transcatheter arterial chemoembolization treatment were the independent predictors for the 5-year survival rate for HCC patients. The model was PI = 0.377 × NLR + 0.554 × HG + 0.927 × PRM + 0.778 × MVI + 0.740 × NT - 0.831 × transcatheter arterial chemoembolization (TACE). In the prediction model group, AUROC was 0.832 and the PI cutoff value was 3.38. The sensitivity, specificity, and accuracy were 78.0%, 80%, and 79.2%, respectively. In model evaluation group, AUROC was 0.822, and the PI cutoff value was well corresponded to the prediction model group with sensitivity, specificity, and accuracy of 85.0%, 83.3%, and 84.0%, respectively.The PI model can quantify the mortality risk of hepatitis B related HCC with high sensitivity, specificity, and accuracy.

Methodology for Designing Models Predicting Success of Infertility Treatment

OpenAIRE

Alireza Zarinara; Mohammad Mahdi Akhondi; Hojjat Zeraati; Koorsh Kamali; Kazem Mohammad

2016-01-01

Abstract Background: The prediction models for infertility treatment success have presented since 25 years ago. There are scientific principles for designing and applying the prediction models that is also used to predict the success rate of infertility treatment. The purpose of this study is to provide basic principles for designing the model to predic infertility treatment success. Materials and Methods: In this paper, the principles for developing predictive models are explained and...

Sleep and REM sleep behaviour disorder in Parkinson's disease with impulse control disorder.

Science.gov (United States)

Fantini, Maria Livia; Figorilli, Michela; Arnulf, Isabelle; Zibetti, Maurizio; Pereira, Bruno; Beudin, Patricia; Puligheddu, Monica; Cormier-Dequaire, Florence; Lacomblez, Lucette; Benchetrit, Eve; Corvol, Jean Christophe; Cicolin, Alessandro; Lopiano, Leonardo; Marques, Ana; Durif, Franck

2018-03-01

Because the association between rapid eye movement sleep behaviour disorder (RBD) and impulse control disorders (ICDs) in Parkinson's disease (PD) has been debated, we assessed the sleep characteristics and the frequency of RBD using video-polysomnography (v-PSG) in patients with PD with versus without ICDs. Eighty non-demented patients with PD consecutively identified during routine evaluation at three movement disorders centres were enrolled in a case-control study. Forty patients (22 men; mean age: 62.6±9.7 years, Hoehn & Yahr: 2.1±0.6) with one or more current ICDs were age-matched and sex-matched with 40 patients with no history of ICDs (22 men, mean age: 64.9±7.8 years, Hoehn & Yahr: 2.2±0.6). They underwent a detailed sleep interview followed by a full-night in-lab v-PSG. Sleep was scored blindly to ICDs condition and RBD diagnosis included a clinical complaint of enacted dreams and/or documented behaviour during rapid eye movement (REM) sleep, with the presence of quantified REM sleep without atonia (RSWA). Patients with ICDs had a higher arousal index and higher RSWA than those without ICDs (51.9%±28.2%vs 32.2±27.1%, p=0.004). In addition, RBD was more frequent in the ICD group (85%vs53%, p=0.0001). RBD was still associated with ICDs in a multivariate regression analysis including age of onset, PD duration and severity, treatment duration, levodopa-equivalent and dopamine agonist-equivalent daily doses and antidepressant use (OR: 4.9 (95% CI 1.3 to 18.5), p=0.02). This large, controlled series of patients with PD with ICDs assessed by v-PSG confirms the association between ICDs and RBD. Increased surveillance of symptoms of ICDs should be recommended in patients with PD with RBD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The 3D Reference Earth Model: Status and Preliminary Results

Science.gov (United States)

Moulik, P.; Lekic, V.; Romanowicz, B. A.

2017-12-01

In the 20th century, seismologists constructed models of how average physical properties (e.g. density, rigidity, compressibility, anisotropy) vary with depth in the Earth's interior. These one-dimensional (1D) reference Earth models (e.g. PREM) have proven indispensable in earthquake location, imaging of interior structure, understanding material properties under extreme conditions, and as a reference in other fields, such as particle physics and astronomy. Over the past three decades, new datasets motivated more sophisticated efforts that yielded models of how properties vary both laterally and with depth in the Earth's interior. Though these three-dimensional (3D) models exhibit compelling similarities at large scales, differences in the methodology, representation of structure, and dataset upon which they are based, have prevented the creation of 3D community reference models. As part of the REM-3D project, we are compiling and reconciling reference seismic datasets of body wave travel-time measurements, fundamental mode and overtone surface wave dispersion measurements, and normal mode frequencies and splitting functions. These reference datasets are being inverted for a long-wavelength, 3D reference Earth model that describes the robust long-wavelength features of mantle heterogeneity. As a community reference model with fully quantified uncertainties and tradeoffs and an associated publically available dataset, REM-3D will facilitate Earth imaging studies, earthquake characterization, inferences on temperature and composition in the deep interior, and be of improved utility to emerging scientific endeavors, such as neutrino geoscience. Here, we summarize progress made in the construction of the reference long period dataset and present a preliminary version of REM-3D in the upper-mantle. In order to determine the level of detail warranted for inclusion in REM-3D, we analyze the spectrum of discrepancies between models inverted with different subsets of the

Hidden Semi-Markov Models for Predictive Maintenance

Directory of Open Access Journals (Sweden)

Francesco Cartella

2015-01-01

Full Text Available Realistic predictive maintenance approaches are essential for condition monitoring and predictive maintenance of industrial machines. In this work, we propose Hidden Semi-Markov Models (HSMMs with (i no constraints on the state duration density function and (ii being applied to continuous or discrete observation. To deal with such a type of HSMM, we also propose modifications to the learning, inference, and prediction algorithms. Finally, automatic model selection has been made possible using the Akaike Information Criterion. This paper describes the theoretical formalization of the model as well as several experiments performed on simulated and real data with the aim of methodology validation. In all performed experiments, the model is able to correctly estimate the current state and to effectively predict the time to a predefined event with a low overall average absolute error. As a consequence, its applicability to real world settings can be beneficial, especially where in real time the Remaining Useful Lifetime (RUL of the machine is calculated.

The effects of leptin on REM sleep and slow wave delta in rats are reversed by food deprivation.

Science.gov (United States)

Sinton, C M; Fitch, T E; Gershenfeld, H K

1999-09-01

Leptin (ob protein) is an adipose tissue derived circulating hormone that acts at specific receptors in the hypothalamus to reduce food intake. The protein is also critically involved in energy balance and metabolic status. Here the effect of leptin on sleep architecture in rats was evaluated because food consumption and metabolic status are known to influence sleep. Sprague-Dawley rats were chronically implanted with electrodes for EEG and EMG recording and diurnal sleep parameters were quantified over 9-h periods following leptin administration. Murine recombinant leptin (rMuLep) was administered systemically to rats that either had undergone 18 h of prior food deprivation or had received food ad libitum. In the normally fed rats, leptin significantly decreased the duration of rapid eye movement sleep (REMS) by about 30% and increased the duration of slow wave sleep (SWS) by about 13%, the latter effect reflecting enhanced power in the delta frequency band. These results are consistent with studies that have linked changes in metabolic rate with effects on sleep. Leptin administration has previously been shown to alter neuroendocrine parameters that could have mediated these changes in sleep architecture. Unexpectedly, prior food deprivation negated the effect of leptin on both REMS and SWS, a result that emphasizes the significance of the apparent coupling between sleep parameters and energy status.

Decreased sleep spindle density in patients with idiopathic REM sleep behavior disorder and patients with Parkinson's disease.

Science.gov (United States)

Christensen, Julie A E; Kempfner, Jacob; Zoetmulder, Marielle; Leonthin, Helle L; Arvastson, Lars; Christensen, Søren R; Sorensen, Helge B D; Jennum, Poul

2014-03-01

To determine whether sleep spindles (SS) are potentially a biomarker for Parkinson's disease (PD). Fifteen PD patients with REM sleep behavior disorder (PD+RBD), 15 PD patients without RBD (PD-RBD), 15 idiopathic RBD (iRBD) patients and 15 age-matched controls underwent polysomnography (PSG). SS were scored in an extract of data from control subjects. An automatic SS detector using a Matching Pursuit (MP) algorithm and a Support Vector Machine (SVM) was developed and applied to the PSG recordings. The SS densities in N1, N2, N3, all NREM combined and REM sleep were obtained and evaluated across the groups. The SS detector achieved a sensitivity of 84.7% and a specificity of 84.5%. At a significance level of α=1%, the iRBD and PD+RBD patients had a significantly lower SS density than the control group in N2, N3 and all NREM stages combined. At a significance level of α=5%, PD-RBD had a significantly lower SS density in N2 and all NREM stages combined. The lower SS density suggests involvement in pre-thalamic fibers involved in SS generation. SS density is a potential early PD biomarker. It is likely that an automatic SS detector could be a supportive diagnostic tool in the evaluation of iRBD and PD patients. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Reduced upper obstructions in N3 and increased lower obstructions in REM sleep stage detected with manometry.

Science.gov (United States)

Wirth, Markus; Schramm, Juliane; Bautz, Maximilian; Hofauer, Benedikt; Edenharter, Günther; Ott, Armin; Heiser, Clemens

2018-01-01

In obstructive sleep apnea (OSA), airway obstruction occurs at different anatomic levels. The frequency and location of obstructions play a crucial role in the planning of surgical treatment. The aim of this study was to evaluate the pharyngeal obstruction levels in different sleep stages with manometry in OSA patients. In addition, the manometry results were compared with drug-induced sleep endoscopy (DISE). Forty-one patients with OSA received manometry measurements during one night of sleep. All patients were simultaneously evaluated with polysomnography. The frequency of obstructions in different sleep stages was assessed. Twenty patients were additionally studied with DISE. Obstruction levels detected with manometry were compared with DISE. The frequency of upper and to a lesser extent lower obstructions decreased in sleep stage N3. In rapid eye movement (REM) sleep, lower obstructions increased. The overall proportion of upper and lower obstructions detected with manometry corresponded with DISE in 13 of 20 cases. A significant change in the obstruction levels was detected with manometry in N3 and REM sleep. The reduction of both upper and to a lesser extent lower obstructions in N3 suggests more stable airways in slow-wave sleep. Relevant lower obstructions were not detected in DISE compared to manometry in 5 out of 20 examinations. This could be a potential reason for treatment failure of site-specific surgical OSA treatment when only performing DISE preoperatively. Therefore, manometry could be a useful complementary tool in the preoperative evaluation for OSA.

Methodology of modeling and measuring computer architectures for plasma simulations

Science.gov (United States)

Wang, L. P. T.

1977-01-01

A brief introduction to plasma simulation using computers and the difficulties on currently available computers is given. Through the use of an analyzing and measuring methodology - SARA, the control flow and data flow of a particle simulation model REM2-1/2D are exemplified. After recursive refinements the total execution time may be greatly shortened and a fully parallel data flow can be obtained. From this data flow, a matched computer architecture or organization could be configured to achieve the computation bound of an application problem. A sequential type simulation model, an array/pipeline type simulation model, and a fully parallel simulation model of a code REM2-1/2D are proposed and analyzed. This methodology can be applied to other application problems which have implicitly parallel nature.

Modeling and Control of CSTR using Model based Neural Network Predictive Control

OpenAIRE

Shrivastava, Piyush

2012-01-01

This paper presents a predictive control strategy based on neural network model of the plant is applied to Continuous Stirred Tank Reactor (CSTR). This system is a highly nonlinear process; therefore, a nonlinear predictive method, e.g., neural network predictive control, can be a better match to govern the system dynamics. In the paper, the NN model and the way in which it can be used to predict the behavior of the CSTR process over a certain prediction horizon are described, and some commen...

Consensus models to predict endocrine disruption for all ...

Science.gov (United States)

Humans are potentially exposed to tens of thousands of man-made chemicals in the environment. It is well known that some environmental chemicals mimic natural hormones and thus have the potential to be endocrine disruptors. Most of these environmental chemicals have never been tested for their ability to disrupt the endocrine system, in particular, their ability to interact with the estrogen receptor. EPA needs tools to prioritize thousands of chemicals, for instance in the Endocrine Disruptor Screening Program (EDSP). Collaborative Estrogen Receptor Activity Prediction Project (CERAPP) was intended to be a demonstration of the use of predictive computational models on HTS data including ToxCast and Tox21 assays to prioritize a large chemical universe of 32464 unique structures for one specific molecular target – the estrogen receptor. CERAPP combined multiple computational models for prediction of estrogen receptor activity, and used the predicted results to build a unique consensus model. Models were developed in collaboration between 17 groups in the U.S. and Europe and applied to predict the common set of chemicals. Structure-based techniques such as docking and several QSAR modeling approaches were employed, mostly using a common training set of 1677 compounds provided by U.S. EPA, to build a total of 42 classification models and 8 regression models for binding, agonist and antagonist activity. All predictions were evaluated on ToxCast data and on an exte

Energy based prediction models for building acoustics

DEFF Research Database (Denmark)

Brunskog, Jonas

2012-01-01

In order to reach robust and simplified yet accurate prediction models, energy based principle are commonly used in many fields of acoustics, especially in building acoustics. This includes simple energy flow models, the framework of statistical energy analysis (SEA) as well as more elaborated...... principles as, e.g., wave intensity analysis (WIA). The European standards for building acoustic predictions, the EN 12354 series, are based on energy flow and SEA principles. In the present paper, different energy based prediction models are discussed and critically reviewed. Special attention is placed...... on underlying basic assumptions, such as diffuse fields, high modal overlap, resonant field being dominant, etc., and the consequences of these in terms of limitations in the theory and in the practical use of the models....

Comparison of Simple Versus Performance-Based Fall Prediction Models

Directory of Open Access Journals (Sweden)

Shekhar K. Gadkaree BS

2015-05-01

Full Text Available Objective: To compare the predictive ability of standard falls prediction models based on physical performance assessments with more parsimonious prediction models based on self-reported data. Design: We developed a series of fall prediction models progressing in complexity and compared area under the receiver operating characteristic curve (AUC across models. Setting: National Health and Aging Trends Study (NHATS, which surveyed a nationally representative sample of Medicare enrollees (age ≥65 at baseline (Round 1: 2011-2012 and 1-year follow-up (Round 2: 2012-2013. Participants: In all, 6,056 community-dwelling individuals participated in Rounds 1 and 2 of NHATS. Measurements: Primary outcomes were 1-year incidence of “ any fall ” and “ recurrent falls .” Prediction models were compared and validated in development and validation sets, respectively. Results: A prediction model that included demographic information, self-reported problems with balance and coordination, and previous fall history was the most parsimonious model that optimized AUC for both any fall (AUC = 0.69, 95% confidence interval [CI] = [0.67, 0.71] and recurrent falls (AUC = 0.77, 95% CI = [0.74, 0.79] in the development set. Physical performance testing provided a marginal additional predictive value. Conclusion: A simple clinical prediction model that does not include physical performance testing could facilitate routine, widespread falls risk screening in the ambulatory care setting.

Preclinical models used for immunogenicity prediction of therapeutic proteins.

Science.gov (United States)

Brinks, Vera; Weinbuch, Daniel; Baker, Matthew; Dean, Yann; Stas, Philippe; Kostense, Stefan; Rup, Bonita; Jiskoot, Wim

2013-07-01

All therapeutic proteins are potentially immunogenic. Antibodies formed against these drugs can decrease efficacy, leading to drastically increased therapeutic costs and in rare cases to serious and sometimes life threatening side-effects. Many efforts are therefore undertaken to develop therapeutic proteins with minimal immunogenicity. For this, immunogenicity prediction of candidate drugs during early drug development is essential. Several in silico, in vitro and in vivo models are used to predict immunogenicity of drug leads, to modify potentially immunogenic properties and to continue development of drug candidates with expected low immunogenicity. Despite the extensive use of these predictive models, their actual predictive value varies. Important reasons for this uncertainty are the limited/insufficient knowledge on the immune mechanisms underlying immunogenicity of therapeutic proteins, the fact that different predictive models explore different components of the immune system and the lack of an integrated clinical validation. In this review, we discuss the predictive models in use, summarize aspects of immunogenicity that these models predict and explore the merits and the limitations of each of the models.

A Grey NGM(1,1, k) Self-Memory Coupling Prediction Model for Energy Consumption Prediction

Science.gov (United States)

Guo, Xiaojun; Liu, Sifeng; Wu, Lifeng; Tang, Lingling

2014-01-01

Energy consumption prediction is an important issue for governments, energy sector investors, and other related corporations. Although there are several prediction techniques, selection of the most appropriate technique is of vital importance. As for the approximate nonhomogeneous exponential data sequence often emerging in the energy system, a novel grey NGM(1,1, k) self-memory coupling prediction model is put forward in order to promote the predictive performance. It achieves organic integration of the self-memory principle of dynamic system and grey NGM(1,1, k) model. The traditional grey model's weakness as being sensitive to initial value can be overcome by the self-memory principle. In this study, total energy, coal, and electricity consumption of China is adopted for demonstration by using the proposed coupling prediction technique. The results show the superiority of NGM(1,1, k) self-memory coupling prediction model when compared with the results from the literature. Its excellent prediction performance lies in that the proposed coupling model can take full advantage of the systematic multitime historical data and catch the stochastic fluctuation tendency. This work also makes a significant contribution to the enrichment of grey prediction theory and the extension of its application span. PMID:25054174

Development of Rural Emergency Medical System (REMS) with Geospatial Technology in Malaysia

Science.gov (United States)

Ooi, W. H.; Shahrizal, I. M.; Noordin, A.; Nurulain, M. I.; Norhan, M. Y.

2014-02-01

Emergency medical services are dedicated services in providing out-of-hospital transport to definitive care or patients with illnesses and injuries. In this service the response time and the preparedness of medical services is of prime importance. The application of space and geospatial technology such as satellite navigation system and Geographical Information System (GIS) was proven to improve the emergency operation in many developed countries. In collaboration with a medical service NGO, the National Space Agency (ANGKASA) has developed a prototype Rural Emergency Medical System (REMS), focusing on providing medical services to rural areas and incorporating satellite based tracking module integrated with GIS and patience database to improve the response time of the paramedic team during emergency. With the aim to benefit the grassroots community by exploiting space technology, the project was able to prove the system concept which will be addressed in this paper.

Bayesian Predictive Models for Rayleigh Wind Speed

DEFF Research Database (Denmark)

Shahirinia, Amir; Hajizadeh, Amin; Yu, David C

2017-01-01

predictive model of the wind speed aggregates the non-homogeneous distributions into a single continuous distribution. Therefore, the result is able to capture the variation among the probability distributions of the wind speeds at the turbines’ locations in a wind farm. More specifically, instead of using...... a wind speed distribution whose parameters are known or estimated, the parameters are considered as random whose variations are according to probability distributions. The Bayesian predictive model for a Rayleigh which only has a single model scale parameter has been proposed. Also closed-form posterior...... and predictive inferences under different reasonable choices of prior distribution in sensitivity analysis have been presented....

Modeling and Prediction Using Stochastic Differential Equations

DEFF Research Database (Denmark)

Juhl, Rune; Møller, Jan Kloppenborg; Jørgensen, John Bagterp

2016-01-01

Pharmacokinetic/pharmakodynamic (PK/PD) modeling for a single subject is most often performed using nonlinear models based on deterministic ordinary differential equations (ODEs), and the variation between subjects in a population of subjects is described using a population (mixed effects) setup...... deterministic and can predict the future perfectly. A more realistic approach would be to allow for randomness in the model due to e.g., the model be too simple or errors in input. We describe a modeling and prediction setup which better reflects reality and suggests stochastic differential equations (SDEs...

Prediction of hourly solar radiation with multi-model framework

International Nuclear Information System (INIS)

Wu, Ji; Chan, Chee Keong

2013-01-01

Highlights: • A novel approach to predict solar radiation through the use of clustering paradigms. • Development of prediction models based on the intrinsic pattern observed in each cluster. • Prediction based on proper clustering and selection of model on current time provides better results than other methods. • Experiments were conducted on actual solar radiation data obtained from a weather station in Singapore. - Abstract: In this paper, a novel multi-model prediction framework for prediction of solar radiation is proposed. The framework started with the assumption that there are several patterns embedded in the solar radiation series. To extract the underlying pattern, the solar radiation series is first segmented into smaller subsequences, and the subsequences are further grouped into different clusters. For each cluster, an appropriate prediction model is trained. Hence a procedure for pattern identification is developed to identify the proper pattern that fits the current period. Based on this pattern, the corresponding prediction model is applied to obtain the prediction value. The prediction result of the proposed framework is then compared to other techniques. It is shown that the proposed framework provides superior performance as compared to others

Revised predictive equations for salt intrusion modelling in estuaries

NARCIS (Netherlands)

Gisen, J.I.A.; Savenije, H.H.G.; Nijzink, R.C.

2015-01-01

For one-dimensional salt intrusion models to be predictive, we need predictive equations to link model parameters to observable hydraulic and geometric variables. The one-dimensional model of Savenije (1993b) made use of predictive equations for the Van der Burgh coefficient $K$ and the dispersion

Preprocedural Prediction Model for Contrast-Induced Nephropathy Patients.

Science.gov (United States)

Yin, Wen-Jun; Yi, Yi-Hu; Guan, Xiao-Feng; Zhou, Ling-Yun; Wang, Jiang-Lin; Li, Dai-Yang; Zuo, Xiao-Cong

2017-02-03

Several models have been developed for prediction of contrast-induced nephropathy (CIN); however, they only contain patients receiving intra-arterial contrast media for coronary angiographic procedures, which represent a small proportion of all contrast procedures. In addition, most of them evaluate radiological interventional procedure-related variables. So it is necessary for us to develop a model for prediction of CIN before radiological procedures among patients administered contrast media. A total of 8800 patients undergoing contrast administration were randomly assigned in a 4:1 ratio to development and validation data sets. CIN was defined as an increase of 25% and/or 0.5 mg/dL in serum creatinine within 72 hours above the baseline value. Preprocedural clinical variables were used to develop the prediction model from the training data set by the machine learning method of random forest, and 5-fold cross-validation was used to evaluate the prediction accuracies of the model. Finally we tested this model in the validation data set. The incidence of CIN was 13.38%. We built a prediction model with 13 preprocedural variables selected from 83 variables. The model obtained an area under the receiver-operating characteristic (ROC) curve (AUC) of 0.907 and gave prediction accuracy of 80.8%, sensitivity of 82.7%, specificity of 78.8%, and Matthews correlation coefficient of 61.5%. For the first time, 3 new factors are included in the model: the decreased sodium concentration, the INR value, and the preprocedural glucose level. The newly established model shows excellent predictive ability of CIN development and thereby provides preventative measures for CIN. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Time dependent patient no-show predictive modelling development.

Science.gov (United States)

Huang, Yu-Li; Hanauer, David A

2016-05-09

Purpose - The purpose of this paper is to develop evident-based predictive no-show models considering patients' each past appointment status, a time-dependent component, as an independent predictor to improve predictability. Design/methodology/approach - A ten-year retrospective data set was extracted from a pediatric clinic. It consisted of 7,291 distinct patients who had at least two visits along with their appointment characteristics, patient demographics, and insurance information. Logistic regression was adopted to develop no-show models using two-thirds of the data for training and the remaining data for validation. The no-show threshold was then determined based on minimizing the misclassification of show/no-show assignments. There were a total of 26 predictive model developed based on the number of available past appointments. Simulation was employed to test the effective of each model on costs of patient wait time, physician idle time, and overtime. Findings - The results demonstrated the misclassification rate and the area under the curve of the receiver operating characteristic gradually improved as more appointment history was included until around the 20th predictive model. The overbooking method with no-show predictive models suggested incorporating up to the 16th model and outperformed other overbooking methods by as much as 9.4 per cent in the cost per patient while allowing two additional patients in a clinic day. Research limitations/implications - The challenge now is to actually implement the no-show predictive model systematically to further demonstrate its robustness and simplicity in various scheduling systems. Originality/value - This paper provides examples of how to build the no-show predictive models with time-dependent components to improve the overbooking policy. Accurately identifying scheduled patients' show/no-show status allows clinics to proactively schedule patients to reduce the negative impact of patient no-shows.

Analysis of the concept of Ministry of Public Health of the former USSR (35 rem) and republic concept of population residence

International Nuclear Information System (INIS)

1992-01-01

Concept of safe population residence at the contaminated territories accepted by Ministry of Public Health of the USSR in November, 1988 following the Chernobyl accident is discussed. Groundlessness of the introduced 'dose for life' equal 35 rem is marked as well as incompetence of the approach to population residence at contaminated territories. Republic concept of population residence at Belarussian contaminated territories is presented

A Study on Uncertainty Quantification of Reflood Model using CIRCE Methodology

International Nuclear Information System (INIS)

Jeon, Seongsu; Hong, Soonjoon; Oh, Deogyeon; Bang, Youngseok

2013-01-01

The CIRCE method is intended to quantify the uncertainties of the correlations of a code. It may replace the expert judgment generally used. In this study, an uncertainty quantification of reflood model was performed using CIRCE methodology. In this paper, the application process of CIRCE methodology and main results are briefly described. This research is expected to be useful to improve the present audit calculation methodology, KINS-REM. In this study, an uncertainty quantification of reflood model was performed using CIRCE methodology. The application of CIRCE provided the satisfactory results. This research is expected to be useful to improve the present audit calculation methodology, KINS-REM

Model predictive control using fuzzy decision functions

NARCIS (Netherlands)

Kaymak, U.; Costa Sousa, da J.M.

2001-01-01

Fuzzy predictive control integrates conventional model predictive control with techniques from fuzzy multicriteria decision making, translating the goals and the constraints to predictive control in a transparent way. The information regarding the (fuzzy) goals and the (fuzzy) constraints of the

Predicting and Modelling of Survival Data when Cox's Regression Model does not hold

DEFF Research Database (Denmark)

Scheike, Thomas H.; Zhang, Mei-Jie

2002-01-01

Aalen model; additive risk model; counting processes; competing risk; Cox regression; flexible modeling; goodness of fit; prediction of survival; survival analysis; time-varying effects......Aalen model; additive risk model; counting processes; competing risk; Cox regression; flexible modeling; goodness of fit; prediction of survival; survival analysis; time-varying effects...

Evaluating the Predictive Value of Growth Prediction Models

Science.gov (United States)

Murphy, Daniel L.; Gaertner, Matthew N.

2014-01-01

This study evaluates four growth prediction models--projection, student growth percentile, trajectory, and transition table--commonly used to forecast (and give schools credit for) middle school students' future proficiency. Analyses focused on vertically scaled summative mathematics assessments, and two performance standards conditions (high…

Uncertainties in model-based outcome predictions for treatment planning

International Nuclear Information System (INIS)

Deasy, Joseph O.; Chao, K.S. Clifford; Markman, Jerry

2001-01-01

Purpose: Model-based treatment-plan-specific outcome predictions (such as normal tissue complication probability [NTCP] or the relative reduction in salivary function) are typically presented without reference to underlying uncertainties. We provide a method to assess the reliability of treatment-plan-specific dose-volume outcome model predictions. Methods and Materials: A practical method is proposed for evaluating model prediction based on the original input data together with bootstrap-based estimates of parameter uncertainties. The general framework is applicable to continuous variable predictions (e.g., prediction of long-term salivary function) and dichotomous variable predictions (e.g., tumor control probability [TCP] or NTCP). Using bootstrap resampling, a histogram of the likelihood of alternative parameter values is generated. For a given patient and treatment plan we generate a histogram of alternative model results by computing the model predicted outcome for each parameter set in the bootstrap list. Residual uncertainty ('noise') is accounted for by adding a random component to the computed outcome values. The residual noise distribution is estimated from the original fit between model predictions and patient data. Results: The method is demonstrated using a continuous-endpoint model to predict long-term salivary function for head-and-neck cancer patients. Histograms represent the probabilities for the level of posttreatment salivary function based on the input clinical data, the salivary function model, and the three-dimensional dose distribution. For some patients there is significant uncertainty in the prediction of xerostomia, whereas for other patients the predictions are expected to be more reliable. In contrast, TCP and NTCP endpoints are dichotomous, and parameter uncertainties should be folded directly into the estimated probabilities, thereby improving the accuracy of the estimates. Using bootstrap parameter estimates, competing treatment

Prediction error, ketamine and psychosis: An updated model.

Science.gov (United States)

Corlett, Philip R; Honey, Garry D; Fletcher, Paul C

2016-11-01

In 2007, we proposed an explanation of delusion formation as aberrant prediction error-driven associative learning. Further, we argued that the NMDA receptor antagonist ketamine provided a good model for this process. Subsequently, we validated the model in patients with psychosis, relating aberrant prediction error signals to delusion severity. During the ensuing period, we have developed these ideas, drawing on the simple principle that brains build a model of the world and refine it by minimising prediction errors, as well as using it to guide perceptual inferences. While previously we focused on the prediction error signal per se, an updated view takes into account its precision, as well as the precision of prior expectations. With this expanded perspective, we see several possible routes to psychotic symptoms - which may explain the heterogeneity of psychotic illness, as well as the fact that other drugs, with different pharmacological actions, can produce psychotomimetic effects. In this article, we review the basic principles of this model and highlight specific ways in which prediction errors can be perturbed, in particular considering the reliability and uncertainty of predictions. The expanded model explains hallucinations as perturbations of the uncertainty mediated balance between expectation and prediction error. Here, expectations dominate and create perceptions by suppressing or ignoring actual inputs. Negative symptoms may arise due to poor reliability of predictions in service of action. By mapping from biology to belief and perception, the account proffers new explanations of psychosis. However, challenges remain. We attempt to address some of these concerns and suggest future directions, incorporating other symptoms into the model, building towards better understanding of psychosis. © The Author(s) 2016.

Costly Signaling Theory of REM Sleep and Dreams

Directory of Open Access Journals (Sweden)

Patrick McNamara

2007-01-01

Full Text Available The function of REM sleep dreaming is still unknown. We situate our approach to understanding dream phenomenology and dream function within that part of evolutionary theory known as Costly Signaling Theory (CST. We contend that many of the signals produced by the dreaming brain can be and should be construed as “costly signals”—emotions or mental simulations that produce daytime behavioral dispositions that are costly to the dreamer. For example, often the dreamer will appear in the dream as handicapped in some way (i.e., no clothes, no ID, no money, is under attack, being chased etc.. The dreamer, during waking life, is then influenced by the carry-over effect of the unpleasant dream content. The informational and affective content of the dream creates a mental set in the dreamer that operates during the daytime to facilitate the signaling of a “handicapped” Self. The subtle signaling effect might be via display of the intense emotions or physical demeanor that had first appeared in the dream. When the dreamer shares his dream with others the dream has a more direct impact on waking life and social interactions. In effect, the dreamer uses his or her dreams to adopt a self-handicapping strategy when dealing with significant others. The increased use of costly signals (the self-handicapping strategy during the daytime then facilitates some vital communicative goal of the dreamer.

Predictive Capability Maturity Model for computational modeling and simulation.

Energy Technology Data Exchange (ETDEWEB)

Oberkampf, William Louis; Trucano, Timothy Guy; Pilch, Martin M.

2007-10-01

The Predictive Capability Maturity Model (PCMM) is a new model that can be used to assess the level of maturity of computational modeling and simulation (M&S) efforts. The development of the model is based on both the authors experience and their analysis of similar investigations in the past. The perspective taken in this report is one of judging the usefulness of a predictive capability that relies on the numerical solution to partial differential equations to better inform and improve decision making. The review of past investigations, such as the Software Engineering Institute's Capability Maturity Model Integration and the National Aeronautics and Space Administration and Department of Defense Technology Readiness Levels, indicates that a more restricted, more interpretable method is needed to assess the maturity of an M&S effort. The PCMM addresses six contributing elements to M&S: (1) representation and geometric fidelity, (2) physics and material model fidelity, (3) code verification, (4) solution verification, (5) model validation, and (6) uncertainty quantification and sensitivity analysis. For each of these elements, attributes are identified that characterize four increasing levels of maturity. Importantly, the PCMM is a structured method for assessing the maturity of an M&S effort that is directed toward an engineering application of interest. The PCMM does not assess whether the M&S effort, the accuracy of the predictions, or the performance of the engineering system satisfies or does not satisfy specified application requirements.

Model complexity control for hydrologic prediction

NARCIS (Netherlands)

Schoups, G.; Van de Giesen, N.C.; Savenije, H.H.G.

2008-01-01

A common concern in hydrologic modeling is overparameterization of complex models given limited and noisy data. This leads to problems of parameter nonuniqueness and equifinality, which may negatively affect prediction uncertainties. A systematic way of controlling model complexity is therefore

A Test of the Reciprocal-Effects Model of Academic Achievement and Academic Self-Concept in Regular Classes and Special Classes for the Gifted

Science.gov (United States)

Preckel, Franzis; Schmidt, Isabelle; Stumpf, Eva; Motschenbacher, Monika; Vogl, Katharina; Schneider, Wolfgang

2017-01-01

According to the reciprocal-effects model (REM), prior academic self-concept (ASC) has a positive effect on subsequent achievement beyond what can be explained in terms of prior achievement and vice versa. The present study investigated the REM for students studying in special classes for the gifted compared to students studying in regular…

Predictive Model of Systemic Toxicity (SOT)

Science.gov (United States)

In an effort to ensure chemical safety in light of regulatory advances away from reliance on animal testing, USEPA and L’Oréal have collaborated to develop a quantitative systemic toxicity prediction model. Prediction of human systemic toxicity has proved difficult and remains a ...

Using Pareto points for model identification in predictive toxicology

Science.gov (United States)

2013-01-01

Predictive toxicology is concerned with the development of models that are able to predict the toxicity of chemicals. A reliable prediction of toxic effects of chemicals in living systems is highly desirable in cosmetics, drug design or food protection to speed up the process of chemical compound discovery while reducing the need for lab tests. There is an extensive literature associated with the best practice of model generation and data integration but management and automated identification of relevant models from available collections of models is still an open problem. Currently, the decision on which model should be used for a new chemical compound is left to users. This paper intends to initiate the discussion on automated model identification. We present an algorithm, based on Pareto optimality, which mines model collections and identifies a model that offers a reliable prediction for a new chemical compound. The performance of this new approach is verified for two endpoints: IGC50 and LogP. The results show a great potential for automated model identification methods in predictive toxicology. PMID:23517649

Physical and JIT Model Based Hybrid Modeling Approach for Building Thermal Load Prediction

Science.gov (United States)

Iino, Yutaka; Murai, Masahiko; Murayama, Dai; Motoyama, Ichiro

Energy conservation in building fields is one of the key issues in environmental point of view as well as that of industrial, transportation and residential fields. The half of the total energy consumption in a building is occupied by HVAC (Heating, Ventilating and Air Conditioning) systems. In order to realize energy conservation of HVAC system, a thermal load prediction model for building is required. This paper propose a hybrid modeling approach with physical and Just-in-Time (JIT) model for building thermal load prediction. The proposed method has features and benefits such as, (1) it is applicable to the case in which past operation data for load prediction model learning is poor, (2) it has a self checking function, which always supervises if the data driven load prediction and the physical based one are consistent or not, so it can find if something is wrong in load prediction procedure, (3) it has ability to adjust load prediction in real-time against sudden change of model parameters and environmental conditions. The proposed method is evaluated with real operation data of an existing building, and the improvement of load prediction performance is illustrated.

Logistic regression modelling: procedures and pitfalls in developing and interpreting prediction models

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Nataša Šarlija

2017-01-01

Full Text Available This study sheds light on the most common issues related to applying logistic regression in prediction models for company growth. The purpose of the paper is 1 to provide a detailed demonstration of the steps in developing a growth prediction model based on logistic regression analysis, 2 to discuss common pitfalls and methodological errors in developing a model, and 3 to provide solutions and possible ways of overcoming these issues. Special attention is devoted to the question of satisfying logistic regression assumptions, selecting and defining dependent and independent variables, using classification tables and ROC curves, for reporting model strength, interpreting odds ratios as effect measures and evaluating performance of the prediction model. Development of a logistic regression model in this paper focuses on a prediction model of company growth. The analysis is based on predominantly financial data from a sample of 1471 small and medium-sized Croatian companies active between 2009 and 2014. The financial data is presented in the form of financial ratios divided into nine main groups depicting following areas of business: liquidity, leverage, activity, profitability, research and development, investing and export. The growth prediction model indicates aspects of a business critical for achieving high growth. In that respect, the contribution of this paper is twofold. First, methodological, in terms of pointing out pitfalls and potential solutions in logistic regression modelling, and secondly, theoretical, in terms of identifying factors responsible for high growth of small and medium-sized companies.

The Dramatic Development of the Parable of the Prodigal Son in the Sacramental Play by Alonso Remón

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Rafael Massanet Rodríguez

2017-11-01

Full Text Available The parable of the prodigal son is circumscribed as a predominant theme for the authors of the Spanish Golden Age to develop the plot of some of his autos sacramentales. However, among all these playwrights, the figure of Alonso Remón and his piece have been largely ignored. This article reviews the sacramental career of this author and highlights its importance and differences compared to other comedies that address the same theme.

Model output statistics applied to wind power prediction

Energy Technology Data Exchange (ETDEWEB)

Joensen, A; Giebel, G; Landberg, L [Risoe National Lab., Roskilde (Denmark); Madsen, H; Nielsen, H A [The Technical Univ. of Denmark, Dept. of Mathematical Modelling, Lyngby (Denmark)

1999-03-01

Being able to predict the output of a wind farm online for a day or two in advance has significant advantages for utilities, such as better possibility to schedule fossil fuelled power plants and a better position on electricity spot markets. In this paper prediction methods based on Numerical Weather Prediction (NWP) models are considered. The spatial resolution used in NWP models implies that these predictions are not valid locally at a specific wind farm. Furthermore, due to the non-stationary nature and complexity of the processes in the atmosphere, and occasional changes of NWP models, the deviation between the predicted and the measured wind will be time dependent. If observational data is available, and if the deviation between the predictions and the observations exhibits systematic behavior, this should be corrected for; if statistical methods are used, this approaches is usually referred to as MOS (Model Output Statistics). The influence of atmospheric turbulence intensity, topography, prediction horizon length and auto-correlation of wind speed and power is considered, and to take the time-variations into account, adaptive estimation methods are applied. Three estimation techniques are considered and compared, Extended Kalman Filtering, recursive least squares and a new modified recursive least squares algorithm. (au) EU-JOULE-3. 11 refs.

Neuro-fuzzy modeling in bankruptcy prediction

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Vlachos D.

2003-01-01

Full Text Available For the past 30 years the problem of bankruptcy prediction had been thoroughly studied. From the paper of Altman in 1968 to the recent papers in the '90s, the progress of prediction accuracy was not satisfactory. This paper investigates an alternative modeling of the system (firm, combining neural networks and fuzzy controllers, i.e. using neuro-fuzzy models. Classical modeling is based on mathematical models that describe the behavior of the firm under consideration. The main idea of fuzzy control, on the other hand, is to build a model of a human control expert who is capable of controlling the process without thinking in a mathematical model. This control expert specifies his control action in the form of linguistic rules. These control rules are translated into the framework of fuzzy set theory providing a calculus, which can stimulate the behavior of the control expert and enhance its performance. The accuracy of the model is studied using datasets from previous research papers.

Short-Term Wind Speed Prediction Using EEMD-LSSVM Model

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Aiqing Kang

2017-01-01

Full Text Available Hybrid Ensemble Empirical Mode Decomposition (EEMD and Least Square Support Vector Machine (LSSVM is proposed to improve short-term wind speed forecasting precision. The EEMD is firstly utilized to decompose the original wind speed time series into a set of subseries. Then the LSSVM models are established to forecast these subseries. Partial autocorrelation function is adopted to analyze the inner relationships between the historical wind speed series in order to determine input variables of LSSVM models for prediction of every subseries. Finally, the superposition principle is employed to sum the predicted values of every subseries as the final wind speed prediction. The performance of hybrid model is evaluated based on six metrics. Compared with LSSVM, Back Propagation Neural Networks (BP, Auto-Regressive Integrated Moving Average (ARIMA, combination of Empirical Mode Decomposition (EMD with LSSVM, and hybrid EEMD with ARIMA models, the wind speed forecasting results show that the proposed hybrid model outperforms these models in terms of six metrics. Furthermore, the scatter diagrams of predicted versus actual wind speed and histograms of prediction errors are presented to verify the superiority of the hybrid model in short-term wind speed prediction.

PREDICTED PERCENTAGE DISSATISFIED (PPD) MODEL ...

African Journals Online (AJOL)

HOD

their low power requirements, are relatively cheap and are environment friendly. ... PREDICTED PERCENTAGE DISSATISFIED MODEL EVALUATION OF EVAPORATIVE COOLING ... The performance of direct evaporative coolers is a.

Effect on Prediction when Modeling Covariates in Bayesian Nonparametric Models.

Science.gov (United States)

Cruz-Marcelo, Alejandro; Rosner, Gary L; Müller, Peter; Stewart, Clinton F

2013-04-01

In biomedical research, it is often of interest to characterize biologic processes giving rise to observations and to make predictions of future observations. Bayesian nonparametric methods provide a means for carrying out Bayesian inference making as few assumptions about restrictive parametric models as possible. There are several proposals in the literature for extending Bayesian nonparametric models to include dependence on covariates. Limited attention, however, has been directed to the following two aspects. In this article, we examine the effect on fitting and predictive performance of incorporating covariates in a class of Bayesian nonparametric models by one of two primary ways: either in the weights or in the locations of a discrete random probability measure. We show that different strategies for incorporating continuous covariates in Bayesian nonparametric models can result in big differences when used for prediction, even though they lead to otherwise similar posterior inferences. When one needs the predictive density, as in optimal design, and this density is a mixture, it is better to make the weights depend on the covariates. We demonstrate these points via a simulated data example and in an application in which one wants to determine the optimal dose of an anticancer drug used in pediatric oncology.

Modeling the prediction of business intelligence system effectiveness.

Science.gov (United States)

Weng, Sung-Shun; Yang, Ming-Hsien; Koo, Tian-Lih; Hsiao, Pei-I

2016-01-01

Although business intelligence (BI) technologies are continually evolving, the capability to apply BI technologies has become an indispensable resource for enterprises running in today's complex, uncertain and dynamic business environment. This study performed pioneering work by constructing models and rules for the prediction of business intelligence system effectiveness (BISE) in relation to the implementation of BI solutions. For enterprises, effectively managing critical attributes that determine BISE to develop prediction models with a set of rules for self-evaluation of the effectiveness of BI solutions is necessary to improve BI implementation and ensure its success. The main study findings identified the critical prediction indicators of BISE that are important to forecasting BI performance and highlighted five classification and prediction rules of BISE derived from decision tree structures, as well as a refined regression prediction model with four critical prediction indicators constructed by logistic regression analysis that can enable enterprises to improve BISE while effectively managing BI solution implementation and catering to academics to whom theory is important.

[Application of ARIMA model on prediction of malaria incidence].

Science.gov (United States)

Jing, Xia; Hua-Xun, Zhang; Wen, Lin; Su-Jian, Pei; Ling-Cong, Sun; Xiao-Rong, Dong; Mu-Min, Cao; Dong-Ni, Wu; Shunxiang, Cai

2016-01-29

To predict the incidence of local malaria of Hubei Province applying the Autoregressive Integrated Moving Average model (ARIMA). SPSS 13.0 software was applied to construct the ARIMA model based on the monthly local malaria incidence in Hubei Province from 2004 to 2009. The local malaria incidence data of 2010 were used for model validation and evaluation. The model of ARIMA (1, 1, 1) (1, 1, 0) 12 was tested as relatively the best optimal with the AIC of 76.085 and SBC of 84.395. All the actual incidence data were in the range of 95% CI of predicted value of the model. The prediction effect of the model was acceptable. The ARIMA model could effectively fit and predict the incidence of local malaria of Hubei Province.

Enhancement of Neocortical-Medial Temporal EEG Correlations during Non-REM Sleep

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Nikolai Axmacher

2008-01-01

Full Text Available Interregional interactions of oscillatory activity are crucial for the integrated processing of multiple brain regions. However, while the EEG in virtually all brain structures passes through substantial modifications during sleep, it is still an open question whether interactions between neocortical and medial temporal EEG oscillations also depend on the state of alertness. Several previous studies in animals and humans suggest that hippocampal-neocortical interactions crucially depend on the state of alertness (i.e., waking state or sleep. Here, we analyzed scalp and intracranial EEG recordings during sleep and waking state in epilepsy patients undergoing presurgical evaluation. We found that the amplitudes of oscillations within the medial temporal lobe and the neocortex were more closely correlated during sleep, in particular during non-REM sleep, than during waking state. Possibly, the encoding of novel sensory inputs, which mainly occurs during waking state, requires that medial temporal dynamics are rather independent from neocortical dynamics, while the consolidation of memories during sleep may demand closer interactions between MTL and neocortex.

PREDICTIVE CAPACITY OF ARCH FAMILY MODELS

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Raphael Silveira Amaro

2016-03-01

Full Text Available In the last decades, a remarkable number of models, variants from the Autoregressive Conditional Heteroscedastic family, have been developed and empirically tested, making extremely complex the process of choosing a particular model. This research aim to compare the predictive capacity, using the Model Confidence Set procedure, than five conditional heteroskedasticity models, considering eight different statistical probability distributions. The financial series which were used refers to the log-return series of the Bovespa index and the Dow Jones Industrial Index in the period between 27 October 2008 and 30 December 2014. The empirical evidences showed that, in general, competing models have a great homogeneity to make predictions, either for a stock market of a developed country or for a stock market of a developing country. An equivalent result can be inferred for the statistical probability distributions that were used.

Seasonal predictability of Kiremt rainfall in coupled general circulation models

Science.gov (United States)

Gleixner, Stephanie; Keenlyside, Noel S.; Demissie, Teferi D.; Counillon, François; Wang, Yiguo; Viste, Ellen

2017-11-01

The Ethiopian economy and population is strongly dependent on rainfall. Operational seasonal predictions for the main rainy season (Kiremt, June-September) are based on statistical approaches with Pacific sea surface temperatures (SST) as the main predictor. Here we analyse dynamical predictions from 11 coupled general circulation models for the Kiremt seasons from 1985-2005 with the forecasts starting from the beginning of May. We find skillful predictions from three of the 11 models, but no model beats a simple linear prediction model based on the predicted Niño3.4 indices. The skill of the individual models for dynamically predicting Kiremt rainfall depends on the strength of the teleconnection between Kiremt rainfall and concurrent Pacific SST in the models. Models that do not simulate this teleconnection fail to capture the observed relationship between Kiremt rainfall and the large-scale Walker circulation.

Prediction of lithium-ion battery capacity with metabolic grey model

International Nuclear Information System (INIS)

Chen, Lin; Lin, Weilong; Li, Junzi; Tian, Binbin; Pan, Haihong

2016-01-01

Given the popularity of Lithium-ion batteries in EVs (electric vehicles), predicting the capacity quickly and accurately throughout a battery's full life-time is still a challenging issue for ensuring the reliability of EVs. This paper proposes an approach in predicting the varied capacity with discharge cycles based on metabolic grey theory and consider issues from two perspectives: 1) three metabolic grey models will be presented, including MGM (metabolic grey model), MREGM (metabolic Residual-error grey model), and MMREGM (metabolic Markov-residual-error grey model); 2) the universality of these models will be explored under different conditions (such as various discharge rates and temperatures). Furthermore, the research findings in this paper demonstrate the excellent performance of the prediction depending on the three models; however, the precision of the MREGM model is inferior compared to the others. Therefore, we have obtained the conclusion in which the MGM model and the MMREGM model have excellent performances in predicting the capacity under a variety of load conditions, even using few data points for modeling. Also, the universality of the metabolic grey prediction theory is verified by predicting the capacity of batteries under different discharge rates and different temperatures. - Highlights: • The metabolic mechanism is introduced in a grey system for capacity prediction. • Three metabolic grey models are presented and studied. • The universality of these models under different conditions is assessed. • A few data points are required for predicting the capacity with these models.

Comparison of joint modeling and landmarking for dynamic prediction under an illness-death model.

Science.gov (United States)

Suresh, Krithika; Taylor, Jeremy M G; Spratt, Daniel E; Daignault, Stephanie; Tsodikov, Alexander

2017-11-01

Dynamic prediction incorporates time-dependent marker information accrued during follow-up to improve personalized survival prediction probabilities. At any follow-up, or "landmark", time, the residual time distribution for an individual, conditional on their updated marker values, can be used to produce a dynamic prediction. To satisfy a consistency condition that links dynamic predictions at different time points, the residual time distribution must follow from a prediction function that models the joint distribution of the marker process and time to failure, such as a joint model. To circumvent the assumptions and computational burden associated with a joint model, approximate methods for dynamic prediction have been proposed. One such method is landmarking, which fits a Cox model at a sequence of landmark times, and thus is not a comprehensive probability model of the marker process and the event time. Considering an illness-death model, we derive the residual time distribution and demonstrate that the structure of the Cox model baseline hazard and covariate effects under the landmarking approach do not have simple form. We suggest some extensions of the landmark Cox model that should provide a better approximation. We compare the performance of the landmark models with joint models using simulation studies and cognitive aging data from the PAQUID study. We examine the predicted probabilities produced under both methods using data from a prostate cancer study, where metastatic clinical failure is a time-dependent covariate for predicting death following radiation therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Grey NGM(1,1,k Self-Memory Coupling Prediction Model for Energy Consumption Prediction

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Xiaojun Guo

2014-01-01

Full Text Available Energy consumption prediction is an important issue for governments, energy sector investors, and other related corporations. Although there are several prediction techniques, selection of the most appropriate technique is of vital importance. As for the approximate nonhomogeneous exponential data sequence often emerging in the energy system, a novel grey NGM(1,1,k self-memory coupling prediction model is put forward in order to promote the predictive performance. It achieves organic integration of the self-memory principle of dynamic system and grey NGM(1,1,k model. The traditional grey model’s weakness as being sensitive to initial value can be overcome by the self-memory principle. In this study, total energy, coal, and electricity consumption of China is adopted for demonstration by using the proposed coupling prediction technique. The results show the superiority of NGM(1,1,k self-memory coupling prediction model when compared with the results from the literature. Its excellent prediction performance lies in that the proposed coupling model can take full advantage of the systematic multitime historical data and catch the stochastic fluctuation tendency. This work also makes a significant contribution to the enrichment of grey prediction theory and the extension of its application span.

Improving Predictive Modeling in Pediatric Drug Development: Pharmacokinetics, Pharmacodynamics, and Mechanistic Modeling

Energy Technology Data Exchange (ETDEWEB)

Slikker, William; Young, John F.; Corley, Rick A.; Dorman, David C.; Conolly, Rory B.; Knudsen, Thomas; Erstad, Brian L.; Luecke, Richard H.; Faustman, Elaine M.; Timchalk, Chuck; Mattison, Donald R.

2005-07-26

A workshop was conducted on November 18?19, 2004, to address the issue of improving predictive models for drug delivery to developing humans. Although considerable progress has been made for adult humans, large gaps remain for predicting pharmacokinetic/pharmacodynamic (PK/PD) outcome in children because most adult models have not been tested during development. The goals of the meeting included a description of when, during development, infants/children become adultlike in handling drugs. The issue of incorporating the most recent advances into the predictive models was also addressed: both the use of imaging approaches and genomic information were considered. Disease state, as exemplified by obesity, was addressed as a modifier of drug pharmacokinetics and pharmacodynamics during development. Issues addressed in this workshop should be considered in the development of new predictive and mechanistic models of drug kinetics and dynamics in the developing human.