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Sample records for sleep loss influences

  1. Nutrition Influences Caffeine-Mediated Sleep Loss in Drosophila.

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    Keebaugh, Erin S; Park, Jin Hong; Su, Chenchen; Yamada, Ryuichi; Ja, William W

    2017-11-01

    Plant-derived caffeine is regarded as a defensive compound produced to prevent herbivory. Caffeine is generally repellent to insects and often used to study the neurological basis for aversive responses in the model insect, Drosophila melanogaster. Caffeine is also studied for its stimulatory properties where sleep or drowsiness is suppressed across a range of species. Since limiting access to food also inhibits fly sleep-an effect known as starvation-induced sleep suppression-we tested whether aversion to caffeinated food results in reduced nutrient intake and assessed how this might influence fly studies on the stimulatory effects of caffeine. We measured sleep and total consumption during the first 24 hours of exposure to caffeinated diets containing a range of sucrose concentrations to determine the relative influence of caffeine and nutrient ingestion on sleep. Experiments were replicated using three fly strains. Caffeine reduced total consumption and nighttime sleep, but only at intermediate sucrose concentrations. Although sleep can be modeled by an exponential dose response to nutrient intake, caffeine-mediated sleep loss cannot be explained by absolute caffeine or sucrose ingestion alone. Instead, reduced sleep strongly correlates with changes in total consumption due to caffeine. Other bitter compounds phenocopy the effect of caffeine on sleep and food intake. Our results suggest that a major effect of dietary caffeine is on fly feeding behavior. Changes in feeding behavior may drive caffeine-mediated sleep loss. Future studies using psychoactive compounds should consider the potential impact of nutrition when investigating effects on sleep. © 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.

  2. The spread of sleep loss influences drug use in adolescent social networks.

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    Sara C Mednick

    2010-03-01

    Full Text Available Troubled sleep is a commonly cited consequence of adolescent drug use, but it has rarely been studied as a cause. Nor have there been any studies of the extent to which sleep behavior can spread in social networks from person to person to person. Here we map the social networks of 8,349 adolescents in order to study how sleep behavior spreads, how drug use behavior spreads, and how a friend's sleep behavior influences one's own drug use. We find clusters of poor sleep behavior and drug use that extend up to four degrees of separation (to one's friends' friends' friends' friends in the social network. Prospective regression models show that being central in the network negatively influences future sleep outcomes, but not vice versa. Moreover, if a friend sleeps sleeps < or =7 hours by 11%. If a friend uses marijuana, it increases the likelihood of marijuana use by 110%. Finally, the likelihood that an individual uses drugs increases by 19% when a friend sleeps < or =7 hours, and a mediation analysis shows that 20% of this effect results from the spread of sleep behavior from one person to another. This is the first study to suggest that the spread of one behavior in social networks influences the spread of another. The results indicate that interventions should focus on healthy sleep to prevent drug use and targeting specific individuals may improve outcomes across the entire social network.

  3. [Natural factors influencing sleep].

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    Jurkowski, Marek K; Bobek-Billewicz, Barbara

    2007-01-01

    Sleep is a universal phenomenon of human and animal lives, although the importance of sleep for homeo-stasis is still unknown. Sleep disturbances influence many behavioral and physiologic processes, leading to health complications including death. On the other hand, sleep improvement can beneficially influence the course of healing of many disorders and can be a prognostic of health recovery. The factors influencing sleep have different biological and chemical origins. They are classical hormones, hypothalamic releasing and inhibitory hormones, neuropeptides, peptides and others as cytokines, prostaglandins, oleamid, adenosine, nitric oxide. These factors regulate most physiologic processes and are likely elements integrating sleep with physiology and physiology with sleep in health and disorders.

  4. Sleep loss and structural plasticity.

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    Areal, Cassandra C; Warby, Simon C; Mongrain, Valérie

    2017-06-01

    Wakefulness and sleep are dynamic states during which brain functioning is modified and shaped. Sleep loss is detrimental to many brain functions and results in structural changes localized at synapses in the nervous system. In this review, we present and discuss some of the latest observations of structural changes following sleep loss in some vertebrates and insects. We also emphasize that these changes are region-specific and cell type-specific and that, most importantly, these structural modifications have functional roles in sleep regulation and brain functions. Selected mechanisms driving structural modifications occurring with sleep loss are also discussed. Overall, recent research highlights that extending wakefulness impacts synapse number and shape, which in turn regulate sleep need and sleep-dependent learning/memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Voluntary Sleep Loss in Rats

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    Oonk, Marcella; Krueger, James M.; Davis, Christopher J.

    2016-01-01

    Study Objectives: Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Methods: Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. Results: After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. Conclusions: We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. Citation: Oonk M, Krueger JM, Davis CJ. Voluntary sleep loss in rats. SLEEP 2016;39(7):1467–1479. PMID:27166236

  6. Sleep loss produces false memories.

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    Susanne Diekelmann

    Full Text Available People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",..., lacking the strongest common associate or theme word (here: "black". Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.

  7. Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise.

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    Fullagar, Hugh H K; Skorski, Sabrina; Duffield, Rob; Hammes, Daniel; Coutts, Aaron J; Meyer, Tim

    2015-02-01

    Although its true function remains unclear, sleep is considered critical to human physiological and cognitive function. Equally, since sleep loss is a common occurrence prior to competition in athletes, this could significantly impact upon their athletic performance. Much of the previous research has reported that exercise performance is negatively affected following sleep loss; however, conflicting findings mean that the extent, influence, and mechanisms of sleep loss affecting exercise performance remain uncertain. For instance, research indicates some maximal physical efforts and gross motor performances can be maintained. In comparison, the few published studies investigating the effect of sleep loss on performance in athletes report a reduction in sport-specific performance. The effects of sleep loss on physiological responses to exercise also remain equivocal; however, it appears a reduction in sleep quality and quantity could result in an autonomic nervous system imbalance, simulating symptoms of the overtraining syndrome. Additionally, increases in pro-inflammatory cytokines following sleep loss could promote immune system dysfunction. Of further concern, numerous studies investigating the effects of sleep loss on cognitive function report slower and less accurate cognitive performance. Based on this context, this review aims to evaluate the importance and prevalence of sleep in athletes and summarises the effects of sleep loss (restriction and deprivation) on exercise performance, and physiological and cognitive responses to exercise. Given the equivocal understanding of sleep and athletic performance outcomes, further research and consideration is required to obtain a greater knowledge of the interaction between sleep and performance.

  8. Sleep loss, learning capacity and academic performance.

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    Curcio, Giuseppe; Ferrara, Michele; De Gennaro, Luigi

    2006-10-01

    At a time when several studies have highlighted the relationship between sleep, learning and memory processes, an in-depth analysis of the effects of sleep deprivation on student learning ability and academic performance would appear to be essential. Most studies have been naturalistic correlative investigations, where sleep schedules were correlated with school and academic achievement. Nonetheless, some authors were able to actively manipulate sleep in order to observe neurocognitive and behavioral consequences, such as learning, memory capacity and school performance. The findings strongly suggest that: (a) students of different education levels (from school to university) are chronically sleep deprived or suffer from poor sleep quality and consequent daytime sleepiness; (b) sleep quality and quantity are closely related to student learning capacity and academic performance; (c) sleep loss is frequently associated with poor declarative and procedural learning in students; (d) studies in which sleep was actively restricted or optimized showed, respectively, a worsening and an improvement in neurocognitive and academic performance. These results may been related to the specific involvement of the prefrontal cortex (PFC) in vulnerability to sleep loss. Most methodological limitations are discussed and some future research goals are suggested.

  9. The metabolic burden of sleep loss.

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    Schmid, Sebastian M; Hallschmid, Manfred; Schultes, Bernd

    2015-01-01

    In parallel with the increasing prevalence of obesity and type 2 diabetes, sleep loss has become common in modern societies. An increasing number of epidemiological studies show an association between short sleep duration, sleep disturbances, and circadian desynchronisation of sleep with adverse metabolic traits, in particular obesity and type 2 diabetes. Furthermore, experimental studies point to distinct mechanisms by which insufficient sleep adversely affects metabolic health. Changes in the activity of neuroendocrine systems seem to be major mediators of the detrimental metabolic effects of insufficient sleep, through favouring neurobehavioural outcomes such as increased appetite, enhanced sensitivity to food stimuli, and, ultimately, a surplus in energy intake. The effect of curtailed sleep on physical activity and energy expenditure is less clear, but changes are unlikely to outweigh increases in food intake. Although long-term interventional studies proving a cause and effect association are still scarce, sleep loss seems to be an appealing target for the prevention, and probably treatment, of metabolic disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Does stress influence sleep patterns, food intake, weight gain, abdominal obesity and weight loss interventions and vice versa?

    DEFF Research Database (Denmark)

    Geiker, Nina Rica Wium; Astrup, Arne; Hjorth, Mads Fiil

    2018-01-01

    subjects. This review summarizes the scientific evidence on the role mental stress (either in or not in association with impaired sleep) may play in poor sleep, enhanced appetite, cravings and decreased motivation for physical activity. All these factors contribute to weight gain and obesity, possibly via...

  11. Sleep Loss as a Factor to Induce Cellular and Molecular Inflammatory Variations

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    Gabriela Hurtado-Alvarado

    2013-01-01

    Full Text Available A reduction in the amount of time spent sleeping occurs chronically in modern society. Clinical and experimental studies in humans and animal models have shown that immune function is impaired when sleep loss is experienced. Sleep loss exerts a strong regulatory influence on peripheral levels of inflammatory mediators of the immune response. An increasing number of research projects support the existence of reciprocal regulation between sleep and low-intensity inflammatory response. Recent studies show that sleep deficient humans and rodents exhibit a proinflammatory component; therefore, sleep loss is considered as a risk factor for developing cardiovascular, metabolic, and neurodegenerative diseases (e.g., diabetes, Alzheimer's disease, and multiple sclerosis. Circulating levels of proinflammatory mediators depend on the intensity and duration of the method employed to induce sleep loss. Recognizing the fact that the concentration of proinflammatory mediators is different between acute and chronic sleep-loss may expand the understanding of the relationship between sleep and the immune response. The aim of this review is to integrate data from recent published reports (2002–2013 on the effects of sleep loss on the immune response. This review may allow readers to have an integrated view of the mechanisms involved in central and peripheral deficits induced by sleep loss.

  12. The perilipin homologue, lipid storage droplet 2, regulates sleep homeostasis and prevents learning impairments following sleep loss.

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    Matthew S Thimgan

    2010-08-01

    Full Text Available Extended periods of waking result in physiological impairments in humans, rats, and flies. Sleep homeostasis, the increase in sleep observed following sleep loss, is believed to counter the negative effects of prolonged waking by restoring vital biological processes that are degraded during sleep deprivation. Sleep homeostasis, as with other behaviors, is influenced by both genes and environment. We report here that during periods of starvation, flies remain spontaneously awake but, in contrast to sleep deprivation, do not accrue any of the negative consequences of prolonged waking. Specifically, the homeostatic response and learning impairments that are a characteristic of sleep loss are not observed following prolonged waking induced by starvation. Recently, two genes, brummer (bmm and Lipid storage droplet 2 (Lsd2, have been shown to modulate the response to starvation. bmm mutants have excess fat and are resistant to starvation, whereas Lsd2 mutants are lean and sensitive to starvation. Thus, we hypothesized that bmm and Lsd2 may play a role in sleep regulation. Indeed, bmm mutant flies display a large homeostatic response following sleep deprivation. In contrast, Lsd2 mutant flies, which phenocopy aspects of starvation as measured by low triglyceride stores, do not exhibit a homeostatic response following sleep loss. Importantly, Lsd2 mutant flies are not learning impaired after sleep deprivation. These results provide the first genetic evidence, to our knowledge, that lipid metabolism plays an important role in regulating the homeostatic response and can protect against neuronal impairments induced by prolonged waking.

  13. The effect of sleep loss on next day effort.

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    Engle-Friedman, Mindy; Riela, Suzanne; Golan, Rama; Ventuneac, Ana M; Davis, Christine M; Jefferson, Angela D; Major, Donna

    2003-06-01

    The study had two primary objectives. The first was to determine whether sleep loss results in a preference for tasks demanding minimal effort. The second was to evaluate the quality of performance when participants, under conditions of sleep loss, have control over task demands. In experiment 1, using a repeated-measures design, 50 undergraduate college students were evaluated, following one night of no sleep loss and one night of sleep loss. The Math Effort Task (MET) presented addition problems via computer. Participants were able to select additions at one of five levels of difficulty. Less-demanding problems were selected and more additions were solved correctly when the participants were subject to sleep loss. In experiment 2, 58 undergraduate college students were randomly assigned to a no sleep deprivation or a sleep deprivation condition. Sleep-deprived participants selected less-demanding problems on the MET. Percentage correct on the MET was equivalent for both the non-sleep-deprived and sleep-deprived groups. On a task selection question, the sleep-deprived participants also selected significantly less-demanding non-academic tasks. Increased sleepiness, fatigue, and reaction time were associated with the selection of less difficult tasks. Both groups of participants reported equivalent effort expenditures; sleep-deprived participants did not perceive a reduction in effort. These studies demonstrate that sleep loss results in the choice of low-effort behavior that helps maintain accurate responding.

  14. Public health implications of sleep loss: the community burden.

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    Hillman, David R; Lack, Leon C

    2013-10-21

    Poor sleep imparts a significant personal and societal burden. Therefore, it is important to have accurate estimates of its causes, prevalence and costs to inform health policy. A recent evaluation of the sleep habits of Australians demonstrates that frequent (daily or near daily) sleep difficulties (initiating and maintaining sleep, and experiencing inadequate sleep), daytime fatigue, sleepiness and irritability are highly prevalent (20%-35%). These difficulties are generally more prevalent among females, with the exception of snoring and related difficulties. While about half of these problems are likely to be attributable to specific sleep disorders, the balance appears attributable to poor sleep habits or choices to limit sleep opportunity. Study of the economic impact of sleep disorders demonstrates financial costs to Australia of $5.1 billion per year. This comprises $270 million for health care costs for the conditions themselves, $540 million for care of associated medical conditions attributable to sleep disorders, and about $4.3 billion largely attributable to associated productivity losses and non-medical costs resulting from sleep loss-related accidents. Loss of life quality added a substantial further non-financial cost. While large, these costs were for sleep disorders alone. Additional costs relating to inadequate sleep from poor sleep habits in people without sleep disorders were not considered. Based on the high prevalence of such problems and the known impacts of sleep loss in all its forms on health, productivity and safety, it is likely that these poor sleep habits would add substantially to the costs from sleep disorders alone.

  15. Delayed Sleep and Sleep Loss in University Students.

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    Lack, Leon C.

    1986-01-01

    A sample of 211 first-year psychology students completed a questionnaire of sleep habits and difficulities. It was discovered that Delayed Sleep Phase Syndrome may be a significant problem in university student populations. (Author/JD)

  16. A brief period of sleep deprivation causes spine loss in the dentate gyrus of mice.

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    Raven, Frank; Meerlo, Peter; Van der Zee, Eddy A; Abel, Ted; Havekes, Robbert

    2018-03-24

    Sleep and sleep loss have a profound impact on hippocampal function, leading to memory impairments. Modifications in the strength of synaptic connections directly influences neuronal communication, which is vital for normal brain function, as well as the processing and storage of information. In a recently published study, we found that as little as five hours of sleep deprivation impaired hippocampus-dependent memory consolidation, which was accompanied by a reduction in dendritic spine numbers in hippocampal area CA1. Surprisingly, loss of sleep did not alter the spine density of CA3 neurons. Although sleep deprivation has been reported to affect the function of the dentate gyrus, it is unclear whether a brief period of sleep deprivation impacts spine density in this region. Here, we investigated the impact of a brief period of sleep deprivation on dendritic structure in the dentate gyrus of the dorsal hippocampus. We found that five hours of sleep loss reduces spine density in the dentate gyrus with a prominent effect on branched spines. Interestingly, the inferior blade of the dentate gyrus seems to be more vulnerable in terms of spine loss than the superior blade. This decrease in spine density predominantly in the inferior blade of the dentate gyrus may contribute to the memory deficits observed after sleep loss, as structural reorganization of synaptic networks in this subregion is fundamental for cognitive processes. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Improvement in Obstructive Sleep Apnea With Weight Loss is Dependent on Body Position During Sleep.

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    Joosten, Simon A; Khoo, Jun K; Edwards, Bradley A; Landry, Shane A; Naughton, Matthew T; Dixon, John B; Hamilton, Garun S

    2017-05-01

    Weight loss fails to resolve obstructive sleep apnea (OSA) in most patients; however, it is unknown as to whether weight loss differentially affects OSA in the supine compared with nonsupine sleeping positions. We aimed to determine if weight loss in obese patients with OSA results in a greater reduction in the nonsupine apnea/hypopnea index (AHI) compared with the supine AHI, thus converting participants into supine-predominant OSA. Post hoc analysis of data from a randomized controlled trial assessing the effect of weight loss (bariatric surgery vs. medical weight loss) on OSA in 60 participants with obesity (body mass index: >35 and sleep study at 2 years. Eight of 37 (22%) patients demonstrated a normal nonsupine AHI (sleep avoidance may cure their OSA. © 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.

  18. A link between sleep loss, glucose metabolism and adipokines

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    H.G. Padilha

    2011-10-01

    Full Text Available The present review evaluates the role of sleep and its alteration in triggering problems of glucose metabolism and the possible involvement of adipokines in this process. A reduction in the amount of time spent sleeping has become an endemic condition in modern society, and a search of the current literature has found important associations between sleep loss and alterations of nutritional and metabolic contexts. Studies suggest that sleep loss is associated with problems in glucose metabolism and a higher risk for the development of insulin resistance and type 2 diabetes mellitus. The mechanism involved may be associated with the decreased efficacy of regulation of the hypothalamus-pituitary-adrenal axis by negative feedback mechanisms in sleep-deprivation conditions. In addition, changes in the circadian pattern of growth hormone (GH secretion might also contribute to the alterations in glucose regulation observed during sleep loss. On the other hand, sleep deprivation stress affects adipokines - increasing tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 and decreasing leptin and adiponectin -, thus establishing a possible association between sleep-debt, adipokines and glucose metabolism. Thus, a modified release of adipokines resulting from sleep deprivation could lead to a chronic sub-inflammatory state that could play a central role in the development of insulin resistance and type 2 diabetes mellitus. Further studies are necessary to investigate the role of sleep loss in adipokine release and its relationship with glucose metabolism.

  19. Cell Injury and Repair Resulting from Sleep Loss and Sleep Recovery in Laboratory Rats

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    Everson, Carol A.; Henchen, Christopher J.; Szabo, Aniko; Hogg, Neil

    2014-01-01

    Study Objectives: Increased cell injury would provide the type of change in constitution that would underlie sleep disruption as a risk factor for multiple diseases. The current study was undertaken to investigate cell injury and altered cell fate as consequences of sleep deprivation, which were predicted from systemic clues. Design: Partial (35% sleep reduction) and total sleep deprivation were produced in rats for 10 days, which was tolerated and without overtly deteriorated health. Recovery rats were similarly sleep deprived for 10 days, then allowed undisturbed sleep for 2 days. The plasma, liver, lung, intestine, heart, and spleen were analyzed and compared to control values for damage to DNA, proteins, and lipids; apoptotic cell signaling and death; cell proliferation; and concentrations of glutathione peroxidase and catalase. Measurements and Results: Oxidative DNA damage in totally sleep deprived rats was 139% of control values, with organ-specific effects in the liver (247%), lung (166%), and small intestine (145%). Overall and organ-specific DNA damage was also increased in partially sleep deprived rats. In the intestinal epithelium, total sleep deprivation resulted in 5.3-fold increases in dying cells and 1.5-fold increases in proliferating cells, compared with control. Two days of recovery sleep restored the balance between DNA damage and repair, and resulted in normal or below-normal metabolic burdens and oxidative damage. Conclusions: These findings provide physical evidence that sleep loss causes cell damage, and in a manner expected to predispose to replication errors and metabolic abnormalities; thereby providing linkage between sleep loss and disease risk observed in epidemiological findings. Properties of recovery sleep include biochemical and molecular events that restore balance and decrease cell injury. Citation: Everson CA, Henchen CJ, Szabo A, Hogg N. Cell injury and repair resulting from sleep loss and sleep recovery in laboratory rats

  20. Sleep Loss in Resident Physicians: The Cause of Medical Errors?

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    Milton eKramer

    2010-10-01

    Full Text Available This review begins with the history of the events starting with the death of Libby Zion that lead to the Bell Commission, that the studied her death and made recommendations for improvement that were codified into law in New York state as the 405 law that the ACGME essentially adopted in putting a cap on work hours and establishing the level of staff supervision that must be available to residents in clinical situations particularly the emergency room and acute care units. A summary is then provided of the findings of the laboratory effects of total sleep deprivation including acute total sleep loss and the consequent widespread physiologic alterations, and of the effects of selective and chronic sleep loss. Generally the sequence of responses to increasing sleep loss goes from mood changes to cognitive effects to performance deficits. In the laboratory situation, deficits resulting from sleep deprivation are clearly and definitively demonstrable. Sleep loss in the clinical situation is usually sleep deprivation superimposed on chronic sleep loss. An examination of questionnaire studies, the literature on reports of sleep loss, studies of the reduction of work hours on performance as well as observational and a few interventional studies have yielded contradictory and often equivocal results. The residents generally find they feel better working fewer hours but improvements in patient care are often not reported or do not occur. A change in the attitude of the resident toward his role and his patient has not been salutary. Decreasing sleep loss should have had a positive effect on patient care in reducing medical error, but this remains to be unequivocally demonstrated.

  1. Astrocytic modulation of sleep homeostasis and cognitive consequences of sleep loss.

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    Halassa, Michael M; Florian, Cedrick; Fellin, Tommaso; Munoz, James R; Lee, So-Young; Abel, Ted; Haydon, Philip G; Frank, Marcos G

    2009-01-29

    Astrocytes modulate neuronal activity by releasing chemical transmitters via a process termed gliotransmission. The role of this process in the control of behavior is unknown. Since one outcome of SNARE-dependent gliotransmission is the regulation of extracellular adenosine and because adenosine promotes sleep, we genetically inhibited the release of gliotransmitters and asked if astrocytes play an unsuspected role in sleep regulation. Inhibiting gliotransmission attenuated the accumulation of sleep pressure, assessed by measuring the slow wave activity of the EEG during NREM sleep, and prevented cognitive deficits associated with sleep loss. Since the sleep-suppressing effects of the A1 receptor antagonist CPT were prevented following inhibition of gliotransmission and because intracerebroventricular delivery of CPT to wild-type mice mimicked the transgenic phenotype, we conclude that astrocytes modulate the accumulation of sleep pressure and its cognitive consequences through a pathway involving A1 receptors.

  2. Cell injury and repair resulting from sleep loss and sleep recovery in laboratory rats.

    Science.gov (United States)

    Everson, Carol A; Henchen, Christopher J; Szabo, Aniko; Hogg, Neil

    2014-12-01

    Increased cell injury would provide the type of change in constitution that would underlie sleep disruption as a risk factor for multiple diseases. The current study was undertaken to investigate cell injury and altered cell fate as consequences of sleep deprivation, which were predicted from systemic clues. Partial (35% sleep reduction) and total sleep deprivation were produced in rats for 10 days, which was tolerated and without overtly deteriorated health. Recovery rats were similarly sleep deprived for 10 days, then allowed undisturbed sleep for 2 days. The plasma, liver, lung, intestine, heart, and spleen were analyzed and compared to control values for damage to DNA, proteins, and lipids; apoptotic cell signaling and death; cell proliferation; and concentrations of glutathione peroxidase and catalase. Oxidative DNA damage in totally sleep deprived rats was 139% of control values, with organ-specific effects in the liver (247%), lung (166%), and small intestine (145%). Overall and organ-specific DNA damage was also increased in partially sleep deprived rats. In the intestinal epithelium, total sleep deprivation resulted in 5.3-fold increases in dying cells and 1.5-fold increases in proliferating cells, compared with control. Recovery sleep restored the balance between DNA damage and repair, and resulted in normal or below-normal metabolic burdens and oxidative damage. These findings provide physical evidence that sleep loss causes cell damage, and in a manner expected to predispose to replication errors and metabolic abnormalities; thereby providing linkage between sleep loss and disease risk observed in epidemiological findings. Properties of recovery sleep include biochemical and molecular events that restore balance and decrease cell injury. © 2014 Associated Professional Sleep Societies, LLC.

  3. Sleep loss disrupts Arc expression in dentate gyrus neurons.

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    Delorme, James E; Kodoth, Varna; Aton, Sara J

    2018-04-07

    Sleep loss affects many aspects of cognition, and memory consolidation processes occurring in the hippocampus seem particularly vulnerable to sleep loss. The immediate-early gene Arc plays an essential role in both synaptic plasticity and memory formation, and its expression is altered by sleep. Here, using a variety of techniques, we have characterized the effects of brief (3-h) periods of sleep vs. sleep deprivation (SD) on the expression of Arc mRNA and Arc protein in the mouse hippocampus and cortex. By comparing the relative abundance of mature Arc mRNA with unspliced pre-mRNA, we see evidence that during SD, increases in Arc across the cortex, but not hippocampus, reflect de novo transcription. Arc increases in the hippocampus during SD are not accompanied by changes in pre-mRNA levels, suggesting that increases in mRNA stability, not transcription, drives this change. Using in situ hybridization (together with behavioral observation to quantify sleep amounts), we find that in the dorsal hippocampus, SD minimally affects Arc mRNA expression, and decreases the number of dentate gyrus (DG) granule cells expressing Arc. This is in contrast to neighboring cortical areas, which show large increases in neuronal Arc expression after SD. Using immunohistochemistry, we find that Arc protein expression is also differentially affected in the cortex and DG with SD - while larger numbers of cortical neurons are Arc+, fewer DG granule cells are Arc+, relative to the same regions in sleeping mice. These data suggest that with regard to expression of plasticity-regulating genes, sleep (and SD) can have differential effects in hippocampal and cortical areas. This may provide a clue regarding the susceptibility of performance on hippocampus-dependent tasks to deficits following even brief periods of sleep loss. Copyright © 2018. Published by Elsevier Inc.

  4. Sleep loss and accidents--work hours, life style, and sleep pathology.

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    Akerstedt, Torbjörn; Philip, Pierre; Capelli, Aurore; Kecklund, Göran

    2011-01-01

    A very important outcome of reduced sleep is accidents. The present chapter will attempt to bring together some of the present knowledge in this area. We will focus on the driving situation, for which the evidence of the link between sleep loss and accidents is quite well established, but we will also bring up working life in general where evidence is more sparse. It should be emphasized that reduced sleep as a cause of accidents implies that the mediating factor is sleepiness (or fatigue). This link is discussed elsewhere in this volume, but here we will bring in sleepiness (subjective or physiological) as an explanatory factor of accidents. Another central observation is that many real life accident studies do not link accidents to reduced sleep, but infer reduced sleep and/or sleepiness from the context, like, for example, from work schedules, life styles, or sleep pathology. Reduced sleep is mainly due to suboptimal work schedules (or to a suboptimal life style) or to sleep pathology. We have divided the present chapter into two areas. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Sleep loss as a trigger of mood episodes in bipolar disorder: individual differences based on diagnostic subtype and gender.

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    Lewis, Katie Swaden; Gordon-Smith, Katherine; Forty, Liz; Di Florio, Arianna; Craddock, Nick; Jones, Lisa; Jones, Ian

    2017-09-01

    Background Sleep loss may trigger mood episodes in people with bipolar disorder but individual differences could influence vulnerability to this trigger. Aims To determine whether bipolar subtype (bipolar disorder type I (BP-I) or II (BD-II)) and gender were associated with vulnerability to the sleep loss trigger. Method During a semi-structured interview, 3140 individuals (68% women) with bipolar disorder (66% BD-I) reported whether sleep loss had triggered episodes of high or low mood. DSM-IV diagnosis of bipolar subtype was derived from case notes and interview data. Results Sleep loss triggering episodes of high mood was associated with female gender (odds ratio (OR) = 1.43, 95% CI 1.17-1.75, P < 0.001) and BD-I subtype (OR = 2.81, 95% CI 2.26-3.50, P < 0.001). Analyses on sleep loss triggering low mood were not significant following adjustment for confounders. Conclusions Gender and bipolar subtype may increase vulnerability to high mood following sleep deprivation. This should be considered in situations where patients encounter sleep disruption, such as shift work and international travel. © The Royal College of Psychiatrists 2017.

  6. Dynamic circadian modulation in a biomathematical model for the effects of sleep and sleep loss on waking neurobehavioral performance.

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    McCauley, Peter; Kalachev, Leonid V; Mollicone, Daniel J; Banks, Siobhan; Dinges, David F; Van Dongen, Hans P A

    2013-12-01

    Recent experimental observations and theoretical advances have indicated that the homeostatic equilibrium for sleep/wake regulation--and thereby sensitivity to neurobehavioral impairment from sleep loss--is modulated by prior sleep/wake history. This phenomenon was predicted by a biomathematical model developed to explain changes in neurobehavioral performance across days in laboratory studies of total sleep deprivation and sustained sleep restriction. The present paper focuses on the dynamics of neurobehavioral performance within days in this biomathematical model of fatigue. Without increasing the number of model parameters, the model was updated by incorporating time-dependence in the amplitude of the circadian modulation of performance. The updated model was calibrated using a large dataset from three laboratory experiments on psychomotor vigilance test (PVT) performance, under conditions of sleep loss and circadian misalignment; and validated using another large dataset from three different laboratory experiments. The time-dependence of circadian amplitude resulted in improved goodness-of-fit in night shift schedules, nap sleep scenarios, and recovery from prior sleep loss. The updated model predicts that the homeostatic equilibrium for sleep/wake regulation--and thus sensitivity to sleep loss--depends not only on the duration but also on the circadian timing of prior sleep. This novel theoretical insight has important implications for predicting operator alertness during work schedules involving circadian misalignment such as night shift work.

  7. Sleep homeostatic pressure and PER3 VNTR gene polymorphism influence antidepressant response to sleep deprivation in bipolar depression.

    Science.gov (United States)

    Dallaspezia, Sara; Locatelli, Clara; Lorenzi, Cristina; Pirovano, Adele; Colombo, Cristina; Benedetti, Francesco

    2016-03-01

    Combined Total sleep deprivation (TSD) and light therapy (LT) cause a rapid improvement in bipolar depression which has been hypothesized to be paralleled by changes in sleep homeostasis. Recent studies showed that bipolar patients had lower changes of EEG theta power after sleep and responders to antidepressant TSD+LT slept less and showed a lower increase of EEG theta power then non-responders. A polymorphism in PER3 gene has been associated with diurnal preference, sleep structure and homeostatic response to sleep deprivation in healthy subjects. We hypothesized that the individual variability in the homeostatic response to TSD could be a correlate of antidepressant response and be influenced by genetic factors. We administered three TSD+LT cycles to bipolar depressed patients. Severity of depression was rated on Hamilton Depression Rating Scale. Actigraphic recordings were performed in a group of patients. PER3 polymorphism influenced changes in total sleep time (F=2.24; p=0.024): while PER3(4/4) and PER3(4/5) patients showed a reduction in it after treatment, PER3(5/5) subjects showed an increase of about 40min, suggesting a higher homeostatic pressure. The same polymorphism influenced the change of depressive symptomatology during treatment (F=3.72; p=0.028). Sleep information was recorded till the day after the end of treatment: a longer period of observation could give more information about the possible maintenance of allostatic adaptation. A higher sleep homeostatic pressure reduced the antidepressant response to TSD+LT, while an allostatic adaptation to sleep loss was associated with better response. This process seems to be under genetic control. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Overnight weight loss: relationship with sleep structure and heart rate variability

    OpenAIRE

    Walter Moraes; Dalva Poyares; Christian Guilleminault; Agostinho Rosa; Marco Tulio Mello; Adriana Rueda; Sergio Tufik

    2008-01-01

    Background: Weight loss can be caused by a loss of body mass due to metabolism and by water loss as unsensible water loss, sweating, or excretion in feces and urine. Although weight loss during sleep is a well-known phenomenon, it has not yet been studied in relation to sleep structure or autonomic tonus during sleep. Our study is proposed to be a first step in assessing the relationship between overnight weight loss, sleep structure, and HRV (heart rate variability) parameters.Methods: Twent...

  9. Individualized performance prediction during total sleep deprivation: accounting for trait vulnerability to sleep loss.

    Science.gov (United States)

    Ramakrishnan, Sridhar; Laxminarayan, Srinivas; Thorsley, David; Wesensten, Nancy J; Balkin, Thomas J; Reifman, Jaques

    2012-01-01

    Individual differences in vulnerability to sleep loss can be considerable, and thus, recent efforts have focused on developing individualized models for predicting the effects of sleep loss on performance. Individualized models constructed using a Bayesian formulation, which combines an individual's available performance data with a priori performance predictions from a group-average model, typically need at least 40 h of individual data before showing significant improvement over the group-average model predictions. Here, we improve upon the basic Bayesian formulation for developing individualized models by observing that individuals may be classified into three sleep-loss phenotypes: resilient, average, and vulnerable. For each phenotype, we developed a phenotype-specific group-average model and used these models to identify each individual's phenotype. We then used the phenotype-specific models within the Bayesian formulation to make individualized predictions. Results on psychomotor vigilance test data from 48 individuals indicated that, on average, ∼85% of individual phenotypes were accurately identified within 30 h of wakefulness. The percentage improvement of the proposed approach in 10-h-ahead predictions was 16% for resilient subjects and 6% for vulnerable subjects. The trade-off for these improvements was a slight decrease in prediction accuracy for average subjects.

  10. Dynamic Circadian Modulation in a Biomathematical Model for the Effects of Sleep and Sleep Loss on Waking Neurobehavioral Performance

    Science.gov (United States)

    McCauley, Peter; Kalachev, Leonid V.; Mollicone, Daniel J.; Banks, Siobhan; Dinges, David F.; Van Dongen, Hans P. A.

    2013-01-01

    Recent experimental observations and theoretical advances have indicated that the homeostatic equilibrium for sleep/wake regulation—and thereby sensitivity to neurobehavioral impairment from sleep loss—is modulated by prior sleep/wake history. This phenomenon was predicted by a biomathematical model developed to explain changes in neurobehavioral performance across days in laboratory studies of total sleep deprivation and sustained sleep restriction. The present paper focuses on the dynamics of neurobehavioral performance within days in this biomathematical model of fatigue. Without increasing the number of model parameters, the model was updated by incorporating time-dependence in the amplitude of the circadian modulation of performance. The updated model was calibrated using a large dataset from three laboratory experiments on psychomotor vigilance test (PVT) performance, under conditions of sleep loss and circadian misalignment; and validated using another large dataset from three different laboratory experiments. The time-dependence of circadian amplitude resulted in improved goodness-of-fit in night shift schedules, nap sleep scenarios, and recovery from prior sleep loss. The updated model predicts that the homeostatic equilibrium for sleep/wake regulation—and thus sensitivity to sleep loss—depends not only on the duration but also on the circadian timing of prior sleep. This novel theoretical insight has important implications for predicting operator alertness during work schedules involving circadian misalignment such as night shift work. Citation: McCauley P; Kalachev LV; Mollicone DJ; Banks S; Dinges DF; Van Dongen HPA. Dynamic circadian modulation in a biomathematical model for the effects of sleep and sleep loss on waking neurobehavioral performance. SLEEP 2013;36(12):1987-1997. PMID:24293775

  11. The Influence of Sleep Disorders on Voice Quality.

    Science.gov (United States)

    Rocha, Bruna Rainho; Behlau, Mara

    2017-09-19

    To verify the influence of sleep quality on the voice. Descriptive and analytical cross-sectional study. Data were collected by an online or printed survey divided in three parts: (1) demographic data and vocal health aspects; (2) self-assessment of sleep and vocal quality, and the influence that sleep has on voice; and (3) sleep and voice self-assessment inventories-the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), and the Voice Handicap Index reduced version (VHI-10). A total of 862 people were included (493 women, 369 men), with a mean age of 32 years old (maximum age of 79 and minimum age of 18 years old). The perception of the influence that sleep has on voice showed a difference (P influence a voice handicap are vocal self-assessment, ESS total score, and self-assessment of the influence that sleep has on voice. The absence of daytime sleepiness is a protective factor (odds ratio [OR] > 1) against perceived voice handicap; the presence of daytime sleepiness is a damaging factor (OR influences voice. Perceived poor sleep quality is related to perceived poor vocal quality. Individuals with a voice handicap observe a greater influence of sleep on voice than those without. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  12. Sleep inertia, sleep homeostatic and circadian influences on higher-order cognitive functions.

    Science.gov (United States)

    Burke, Tina M; Scheer, Frank A J L; Ronda, Joseph M; Czeisler, Charles A; Wright, Kenneth P

    2015-08-01

    Sleep inertia, sleep homeostatic and circadian processes modulate cognition, including reaction time, memory, mood and alertness. How these processes influence higher-order cognitive functions is not well known. Six participants completed a 73-day-long study that included two 14-day-long 28-h forced desynchrony protocols to examine separate and interacting influences of sleep inertia, sleep homeostasis and circadian phase on higher-order cognitive functions of inhibitory control and selective visual attention. Cognitive performance for most measures was impaired immediately after scheduled awakening and improved during the first ~2-4 h of wakefulness (decreasing sleep inertia); worsened thereafter until scheduled bedtime (increasing sleep homeostasis); and was worst at ~60° and best at ~240° (circadian modulation, with worst and best phases corresponding to ~09:00 and ~21:00 hours, respectively, in individuals with a habitual wake time of 07:00 hours). The relative influences of sleep inertia, sleep homeostasis and circadian phase depended on the specific higher-order cognitive function task examined. Inhibitory control appeared to be modulated most strongly by circadian phase, whereas selective visual attention for a spatial-configuration search task was modulated most strongly by sleep inertia. These findings demonstrate that some higher-order cognitive processes are differentially sensitive to different sleep-wake regulatory processes. Differential modulation of cognitive functions by different sleep-wake regulatory processes has important implications for understanding mechanisms contributing to performance impairments during adverse circadian phases, sleep deprivation and/or upon awakening from sleep. © 2015 European Sleep Research Society.

  13. Obstructive Sleep Apnoea Syndrome and Weight Loss: Review

    Directory of Open Access Journals (Sweden)

    Douglas C. Cowan

    2012-01-01

    Full Text Available Obstructive sleep apnoea (OSA syndrome is common, and obesity is a major risk factor. Increased peripharyngeal and central adiposity result in increased pharyngeal collapsibility, through increased mechanical loading around the upper airway, reduced tracheal traction on the pharynx, and reduced neuromuscular activity, particularly during sleep. Significant and sustained weight loss, if achieved, is likely to be a useful therapeutic option in the management of OSA and may be attempted by behavioural, pharmacological, and surgical approaches. Behavioural therapy programs that focus on aspects such as dietary intervention, exercise prescription patients and general lifestyle counselling have been tested. Bariatric surgery is an option in the severely obese when nonsurgical measures have failed, and laparoscopic adjustable gastric banding and Roux-en-Y gastric bypass are the most commonly employed techniques in the United Kingdom. Most evidence for efficacy of surgery comes from cohort studies. The role of sibutramine in OSA in the obese patients has been investigated, however, there are concerns regarding associated cardiovascular risk. In this paper the links between obesity and OSA are discussed, and the recent studies evaluating the behavioural, pharmacological and surgical approaches to weight loss in OSA are reviewed.

  14. Emotional memory processing is influenced by sleep quality.

    Science.gov (United States)

    Tempesta, Daniela; De Gennaro, Luigi; Natale, Vincenzo; Ferrara, Michele

    2015-07-01

    The recall of emotional memory is enhanced after sleep and is hindered by sleep deprivation. We used an emotional memory task to assess whether poor sleep quality, as well as sleep deprivation, may influence the accuracy of memory recognition, but also the affective tone associated with the memory. Seventy-five subjects, divided into poor sleeper (PS), good sleeper (GS), and sleep deprivation (SD) groups, completed two recall (R) sessions: R1, 1 h after the encoding phase; and R2, after one night of sleep for PS and GS groups and after one night of sleep deprivation for the SD group. During the encoding phase, the participants rated valence and arousal of 90 pictures. During R1 and R2, the participants first made a yes/no memory judgment of the 45 target pictures intermingled with 30 non-target pictures, then rated valence and arousal of each picture. Recognition accuracy was higher for the PS and GS groups compared to the SD group for all pictures. Emotional valence of the remembered pictures was more negative after sleep deprivation and poor quality sleep, while it was preserved after a good sleep. These results provide the first evidence that poor sleep quality negatively affects emotional valence of memories, within the context of preserved emotional memory consolidation. It is suggested that low sleep quality and lack of sleep may impose a more negative affective tone to memories. The reported effects are not to be ascribed to depressive mood, but to a specific influence of poor sleep quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Intraindividual Increase of Homeostatic Sleep Pressure Across Acute and Chronic Sleep Loss: A High-Density EEG Study.

    Science.gov (United States)

    Maric, Angelina; Lustenberger, Caroline; Werth, Esther; Baumann, Christian R; Poryazova, Rositsa; Huber, Reto

    2017-09-01

    To compare intraindividually the effects of acute sleep deprivation (ASD) and chronic sleep restriction (CSR) on the homeostatic increase in slow wave activity (SWA) and to relate it to impairments in basic cognitive functioning, that is, vigilance. The increase in SWA after ASD (40 hours of wakefulness) and after CSR (seven nights with time in bed restricted to 5 hours per night) relative to baseline sleep was assessed in nine healthy, male participants (age = 18-26 years) by high-density electroencephalography. The SWA increase during the initial part of sleep was compared between the two conditions of sleep loss. The increase in SWA was related to the increase in lapses of vigilance in the psychomotor vigilance task (PVT) during the preceding days. While ASD induced a stronger increase in initial SWA than CSR, the increase was globally correlated across the two conditions in most electrodes. The increase in initial SWA was positively associated with the increase in PVT lapses. The individual homeostatic response in SWA is globally preserved across acute and chronic sleep loss, that is, individuals showing a larger increase after ASD also do so after CSR and vice versa. Furthermore, the increase in SWA is globally correlated to vigilance impairments after sleep loss over both conditions. Thus, the increase in SWA might therefore provide a physiological marker for individual differences in performance impairments after sleep loss. © 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.

  16. Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress

    Science.gov (United States)

    Grønli, Janne; Soulé, Jonathan; Bramham, Clive R.

    2014-01-01

    Sleep has been ascribed a critical role in cognitive functioning. Several lines of evidence implicate sleep in the consolidation of synaptic plasticity and long-term memory. Stress disrupts sleep while impairing synaptic plasticity and cognitive performance. Here, we discuss evidence linking sleep to mechanisms of protein synthesis-dependent synaptic plasticity and synaptic scaling. We then consider how disruption of sleep by acute and chronic stress may impair these mechanisms and degrade sleep function. PMID:24478645

  17. The impact of sleep loss on hippocampal function

    Science.gov (United States)

    Prince, Toni-Moi; Abel, Ted

    2013-01-01

    Hippocampal cellular and molecular processes critical for memory consolidation are affected by the amount and quality of sleep attained. Questions remain with regard to how sleep enhances memory, what parameters of sleep after learning are optimal for memory consolidation, and what underlying hippocampal molecular players are targeted by sleep deprivation to impair memory consolidation and plasticity. In this review, we address these topics with a focus on the detrimental effects of post-learning sleep deprivation on memory consolidation. Obtaining adequate sleep is challenging in a society that values “work around the clock.” Therefore, the development of interventions to combat the negative cognitive effects of sleep deprivation is key. However, there are a limited number of therapeutics that are able to enhance cognition in the face of insufficient sleep. The identification of molecular pathways implicated in the deleterious effects of sleep deprivation on memory could potentially yield new targets for the development of more effective drugs. PMID:24045505

  18. Sleep Deprivation and Recovery Sleep Prior to a Noxious Inflammatory Insult Influence Characteristics and Duration of Pain.

    Science.gov (United States)

    Vanini, Giancarlo

    2016-01-01

    Insufficient sleep and chronic pain are public health epidemics. Sleep loss worsens pain and predicts the development of chronic pain. Whether previous, acute sleep loss and recovery sleep determine pain levels and duration remains poorly understood. This study tested whether acute sleep deprivation and recovery sleep prior to formalin injection alter post-injection pain levels and duration. Male Sprague-Dawley rats (n = 48) underwent sleep deprivation or ad libitum sleep for 9 hours. Thereafter, rats received a subcutaneous injection of formalin or saline into a hind paw. In the recovery sleep group, rats were allowed 24 h between sleep deprivation and the injection of formalin. Mechanical and thermal nociception were assessed using the von Frey test and Hargreaves' method. Nociceptive measures were performed at 1, 3, 7, 10, 14, 17 and 21 days post-injection. Formalin caused bilateral mechanical hypersensitivity (allodynia) that persisted for up to 21 days post-injection. Sleep deprivation significantly enhanced bilateral allodynia. There was a synergistic interaction when sleep deprivation preceded a formalin injection. Rats allowed a recovery sleep period prior to formalin injection developed allodynia only in the injected limb, with higher mechanical thresholds (less allodynia) and a shorter recovery period. There were no persistent changes in thermal nociception. The data suggest that acute sleep loss preceding an inflammatory insult enhances pain and can contribute to chronic pain. The results encourage studies in a model of surgical pain to test whether enhancing sleep reduces pain levels and duration. © 2016 Associated Professional Sleep Societies, LLC.

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

    OpenAIRE

    Vaughn, Bradley; Rotolo,Sean; Roth,Heidi

    2014-01-01

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

  20. Polysomnographic sleep, growth hormone insulin-like growth factor-I axis, leptin, and weight loss

    DEFF Research Database (Denmark)

    Rasmussen, Michael; Wildschiødtz, Gordon; Juul, Anders

    2008-01-01

    compared with nonobese subjects After diet-induced weight loss the differences in GH, free IGF-I, and leptin were no longer present between previously obese and nonobese subjects, whereas a significant difference in sleep duration and total IGF-I levels persisted. Rapid eye movement (REM) sleep, non-REM......Short sleep appears to be strongly associated with obesity and altered metabolic function, and sleep and growth hormone (GH) secretion seems interlinked. In obesity, both the GH-insulin-like-growth-factor-I (GH-IGF-I) axis and sleep have been reported to be abnormal, however, no studies have...... investigated sleep in relation to the GH-IGF-I axis and weight loss in obese subjects. In this study polygraphic sleep recordings, 24-h GH release, 24-h leptin levels, free-IGF-I, total-IGF-I, IGF-binding protein-3 (IGFBP-3), acid-labile subunit (ALS), cortisol and insulin sensitivity were determined in six...

  1. Identification of Genes that Maintain Behavioral and Structural Plasticity during Sleep Loss

    Directory of Open Access Journals (Sweden)

    Laurent Seugnet

    2017-10-01

    Full Text Available Although patients with primary insomnia experience sleep disruption, they are able to maintain normal performance on a variety of cognitive tasks. This observation suggests that insomnia may be a condition where predisposing factors simultaneously increase the risk for insomnia and also mitigate against the deleterious consequences of waking. To gain insight into processes that might regulate sleep and buffer neuronal circuits during sleep loss, we manipulated three genes, fat facet (faf, highwire (hiw and the GABA receptor Resistance to dieldrin (Rdl, that were differentially modulated in a Drosophila model of insomnia. Our results indicate that increasing faf and decreasing hiw or Rdl within wake-promoting large ventral lateral clock neurons (lLNvs induces sleep loss. As expected, sleep loss induced by decreasing hiw in the lLNvs results in deficits in short-term memory and increases of synaptic growth. However, sleep loss induced by knocking down Rdl in the lLNvs protects flies from sleep-loss induced deficits in short-term memory and increases in synaptic markers. Surprisingly, decreasing hiw and Rdl within the Mushroom Bodies (MBs protects against the negative effects of sleep deprivation (SD as indicated by the absence of a subsequent homeostatic response, or deficits in short-term memory. Together these results indicate that specific genes are able to disrupt sleep and protect against the negative consequences of waking in a circuit dependent manner.

  2. Behavioral and biochemical dissociation of arousal and homeostatic sleep need influenced by prior wakeful experience in mice.

    Science.gov (United States)

    Suzuki, Ayako; Sinton, Christopher M; Greene, Robert W; Yanagisawa, Masashi

    2013-06-18

    Sleep is regulated by homeostatic mechanisms, and the low-frequency power in the electroencephalogram (delta power) during non-rapid eye movement sleep reflects homeostatic sleep need. Additionally, sleep is limited by circadian and environmentally influenced arousal. Little is known, however, about the underlying neural substrates for sleep homeostasis and arousal and about the potential link between them. Here, we subjected C57BL/6 mice to 6 h of sleep deprivation using two different methods: gentle handling and continual cage change. Both groups were deprived of sleep to a similar extent (>99%), and, as expected, the delta power increase during recovery sleep was quantitatively similar in both groups. However, in a multiple sleep latency test, the cage change group showed significantly longer sleep latencies than the gentle handling group, indicating that the cage change group had a higher level of arousal despite the similar sleep loss. To investigate the possible biochemical correlates of these behavioral changes, we screened for arousal-related and sleep need-related phosphoprotein markers from the diencephalon. We found that the abundance of highly phosphorylated forms of dynamin 1, a presynaptic neuronal protein, was associated with sleep latency in the multiple sleep latency test. In contrast, the abundance of highly phosphorylated forms of N-myc downstream regulated gene 2, a glial protein, was increased in parallel with delta power. The changes of these protein species disappeared after 2 h of recovery sleep. These results suggest that homeostatic sleep need and arousal can be dissociated behaviorally and biochemically and that phosphorylated N-myc downstream regulated gene 2 and dynamin 1 may serve as markers of homeostatic sleep need and arousal, respectively.

  3. How Acute Total Sleep Loss Affects the Attending Brain: A Meta-Analysis of Neuroimaging Studies

    Science.gov (United States)

    Ma, Ning; Dinges, David F.; Basner, Mathias; Rao, Hengyi

    2015-01-01

    Study Objectives: Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Design: Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. Methods: The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. Results: The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Conclusion: Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. Citation: Ma N, Dinges DF, Basner M, Rao H. How acute total

  4. The influence of road traffic noise on sleep

    Science.gov (United States)

    Eberhardt, J. L.

    1988-12-01

    The influence of road traffic noise on the sleep of adults and 6-11 year old children was studied by using electrophysiological methods. Young adults, unaccustomed to traffic noise, were disturbed by continuous and intermittent traffic noise at 45 dB(A). No sleep disturbances were found for continuous traffic noise at 36 dB(A). Car passages with a peak noise level of 55 dB(A) caused awakenings. The equivalent sound pressure level ( Leq) did not correlate with sleep disturbance effects. A better noise dose description was found in the number of vehicles per night that made most noise. Children wer about 10 dB(A) less sensitive than adults to awakening reactions, and even less sensitive with respect to disturbances of REM sleep and deep sleep. Total habituation to road traffic noise did not occur, even after at least one year of exposure. Sound reduction in the bedroom induced increased amounts of deep sleep for adults and reduced falling-asleep time for children. Road traffic noise during the first hours of a night's sleep tended to disturb sleep more than when it ocurred later in the night, the main effects being a reduction of the total amount of REM sleep during the night and an increased duration of intermittent wakefulness during the hours of exposure.

  5. The effects of sleep loss on young drivers' performance: A systematic review.

    Directory of Open Access Journals (Sweden)

    Shamsi Shekari Soleimanloo

    Full Text Available Young drivers (18-24 years are over-represented in sleep-related crashes (comprising one in five fatal crashes in developed countries primarily due to decreased sleep opportunity, lower tolerance for sleep loss, and ongoing maturation of brain areas associated with driving-related decision making. Impaired driving performance is the proximal reason for most car crashes. There is still a limited body of evidence examining the effects of sleep loss on young drivers' performance, with discrepancies in the methodologies used, and in the definition of outcomes. This study aimed to identify the direction and magnitude of the effects of sleep loss on young drivers' performance, and to appraise the quality of current evidence via a systematic review. Based on the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA approach, 16 eligible studies were selected for review, and their findings summarised. Next, critical elements of these studies were identified, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE guidelines augmented to rate those elements. Using those criteria, the quality of individual papers was calculated and the overall body of evidence for each driving outcome were assigned a quality ranking (from 'very low' to 'high-quality'. Two metrics, the standard deviation of lateral position and number of line crossings, were commonly reported outcomes (although in an overall 'low-quality' body of evidence, with significant impairments after sleep loss identified in 50% of studies. While speed-related outcomes and crash events (also with very low- quality evidence both increased under chronic sleep loss, discrepant findings were reported under conditions of acute total sleep deprivation. It is crucial to obtain more reliable data about the effects of sleep loss on young drivers' performance by using higher quality experimental designs, adopting common protocols, and the use of consistent

  6. Sleep Reactivity and Insomnia: Genetic and Environmental Influences

    Science.gov (United States)

    Drake, Christopher L.; Friedman, Naomi P.; Wright, Kenneth P.; Roth, Thomas

    2011-01-01

    Study Objectives: Determine the genetic and environmental contributions to sleep reactivity and insomnia. Design: Population-based twin cohort. Participants: 1782 individual twins (988 monozygotic or MZ; 1,086 dizygotic or DZ), including 744 complete twin pairs (377 MZ and 367 DZ). Mean age was 22.5 ± 2.8 years; gender distribution was 59% women. Measurements: Sleep reactivity was measured using the Ford Insomnia Response to Stress Test (FIRST). The criterion for insomnia was having difficulty falling asleep, staying asleep, or nonrefreshing sleep “usually or always” for ≥ 1 month, with at least “somewhat” interference with daily functioning. Results: The prevalence of insomnia was 21%. Heritability estimates for sleep reactivity were 29% for females and 43% for males. The environmental variance for sleep reactivity was greater for females and entirely due to nonshared effects. Insomnia was 43% to 55% heritable for males and females, respectively; the sex difference was not significant. The genetic variances in insomnia and FIRST scores were correlated (r = 0.54 in females, r = 0.64 in males), as were the environmental variances (r = 0.32 in females, r = 0.37 in males). In terms of individual insomnia symptoms, difficulty staying asleep (25% to 35%) and nonrefreshing sleep (34% to 35%) showed relatively more genetic influences than difficulty falling asleep (0%). Conclusions: Sleep reactivity to stress has a substantial genetic component, as well as an environmental component. The finding that FIRST scores and insomnia symptoms share genetic influences is consistent with the hypothesis that sleep reactivity may be a genetic vulnerability for developing insomnia. Citation: Drake CL; Friedman NP; Wright KP; Roth T. Sleep reactivity and insomnia: genetic and environmental influences. SLEEP 2011;34(9):1179-1188. PMID:21886355

  7. Sleep Deprivation Alters Choice Strategy Without Altering Uncertainty or Loss Aversion Preferences

    Directory of Open Access Journals (Sweden)

    O'Dhaniel A Mullette-Gillman

    2015-10-01

    Full Text Available Sleep deprivation alters decision making; however, it is unclear what specific cognitive processes are modified to drive altered choices. In this manuscript, we examined how one night of total sleep deprivation (TSD alters economic decision making. We specifically examined changes in uncertainty preferences dissociably from changes in the strategy with which participants engage with presented choice information. With high test-retest reliability, we show that TSD does not alter uncertainty preferences or loss aversion. Rather, TSD alters the information the participants rely upon to make their choices. Utilizing a choice strategy metric which contrasts the influence of maximizing and satisficing information on choice behavior, we find that TSD alters the relative reliance on maximizing information and satisficing information, in the gains domain. This alteration is the result of participants both decreasing their reliance on cognitively-complex maximizing information and a concomitant increase in the use of readily-available satisficing information. TSD did not result in a decrease in overall information use in either domain. These results show that sleep deprivation alters decision making by altering the informational strategies that participants employ, without altering their preferences.

  8. Sleep deprivation alters choice strategy without altering uncertainty or loss aversion preferences.

    Science.gov (United States)

    Mullette-Gillman, O'Dhaniel A; Kurnianingsih, Yoanna A; Liu, Jean C J

    2015-01-01

    Sleep deprivation alters decision making; however, it is unclear what specific cognitive processes are modified to drive altered choices. In this manuscript, we examined how one night of total sleep deprivation (TSD) alters economic decision making. We specifically examined changes in uncertainty preferences dissociably from changes in the strategy with which participants engage with presented choice information. With high test-retest reliability, we show that TSD does not alter uncertainty preferences or loss aversion. Rather, TSD alters the information the participants rely upon to make their choices. Utilizing a choice strategy metric which contrasts the influence of maximizing and satisficing information on choice behavior, we find that TSD alters the relative reliance on maximizing information and satisficing information, in the gains domain. This alteration is the result of participants both decreasing their reliance on cognitively-complex maximizing information and a concomitant increase in the use of readily-available satisficing information. TSD did not result in a decrease in overall information use in either domain. These results show that sleep deprivation alters decision making by altering the informational strategies that participants employ, without altering their preferences.

  9. Loss of Sleep Affects the Ultrastructure of Pyramidal Neurons in the Adolescent Mouse Frontal Cortex.

    Science.gov (United States)

    de Vivo, Luisa; Nelson, Aaron B; Bellesi, Michele; Noguti, Juliana; Tononi, Giulio; Cirelli, Chiara

    2016-04-01

    The adolescent brain may be uniquely affected by acute sleep deprivation (ASD) and chronic sleep restriction (CSR), but direct evidence is lacking. We used electron microscopy to examine how ASD and CSR affect pyramidal neurons in the frontal cortex of adolescent mice, focusing on mitochondria, endosomes, and lysosomes that together perform most basic cellular functions, from nutrient intake to prevention of cellular stress. Adolescent (1-mo-old) mice slept (S) or were sleep deprived (ASD, with novel objects and running wheels) during the first 6-8 h of the light period, chronically sleep restricted (CSR) for > 4 days (using novel objects, running wheels, social interaction, forced locomotion, caffeinated water), or allowed to recover sleep (RS) for ∼32 h after CSR. Ultrastructural analysis of 350 pyramidal neurons was performed (S = 82; ASD = 86; CSR = 103; RS = 79; 4 to 5 mice/group). Several ultrastructural parameters differed in S versus ASD, S versus CSR, CSR versus RS, and S versus RS, although the different methods used to enforce wake may have contributed to some of the differences between short and long sleep loss. Differences included larger cytoplasmic area occupied by mitochondria in CSR versus S, and higher number of secondary lysosomes in CSR versus S and RS. We also found that sleep loss may unmask interindividual differences not obvious during baseline sleep. Moreover, using a combination of 11 ultrastructural parameters, we could predict in up to 80% of cases whether sleep or wake occurred at the single cell level. Ultrastructural analysis may be a powerful tool to identify which cellular organelles, and thus which cellular functions, are most affected by sleep and sleep loss. © 2016 Associated Professional Sleep Societies, LLC.

  10. How acute total sleep loss affects the attending brain: a meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Ma, Ning; Dinges, David F; Basner, Mathias; Rao, Hengyi

    2015-02-01

    Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. © 2015 Associated Professional Sleep Societies, LLC.

  11. One night of sleep loss impairs innovative thinking and flexible decision making.

    Science.gov (United States)

    Harrison, Y; Horne, J A

    1999-05-01

    Recent findings with clinically oriented neuropsychological tests suggest that one night without sleep causes particular impairment to tasks requiring flexible thinking and the updating of plans in the light of new information. This relatively little investigated field of sleep deprivation research has real-world implications for decision makers having lost a night's sleep. To explore this latter perspective further, we adapted a dynamic and realistic marketing decision making "game" embodying the need for these skills, and whereby such performance could be measured. As the task relied on the comprehension of a large amount of written information, a critical reasoning test was also administered to ascertain whether any failure at the marketing game might lie with information acquisition rather than with failures in decision making. Ten healthy highly motivated and trained participants underwent two counterbalanced 36 h trials, sleep vs no sleep. The critical reasoning task was unaffected by sleep loss, whereas performance at the game significantly deteri orated after 32-36 h of sleep loss, when sleep deprivation led to more rigid thinking, increased perseverative errors, and marked difficulty in appreciating an updated situation. At this point, and despite the sleep-deprived participants' best efforts to do well, their play collapsed, unlike that of the nonsleep-deprived participants. Copyright 1999 Academic Press.

  12. Transiently increasing cAMP levels selectively in hippocampal excitatory neurons during sleep deprivation prevents memory deficits caused by sleep loss

    NARCIS (Netherlands)

    Havekes, Robbert; Bruinenberg, Vibeke M.; Tudor, Jennifer C.; Ferri, Sarah L.; Baumann, Arnd; Meerlo, Peter; Abel, Ted

    2014-01-01

    The hippocampus is particularly sensitive to sleep loss. Although previous work has indicated that sleep deprivation impairs hippocampal cAMP signaling, it remains to be determined whether the cognitive deficits associated with sleep deprivation are caused by attenuated cAMP signaling in the

  13. Two year reduction in sleep apnea symptoms and associated diabetes incidence after weight loss in severe obesity.

    Science.gov (United States)

    Grunstein, Ronald R; Stenlöf, Kaj; Hedner, Jan A; Peltonen, Markku; Karason, Kristjan; Sjöström, Lars

    2007-06-01

    To evaluate the effect of bariatric surgery on sleep apnea symptoms and obesity-associated morbidity in patients with severe obesity. Prospective study. University hospitals and community centers in Sweden. We investigated the influence of weight loss surgery (n=1729) on sleep apnea symptoms and obesity-related morbidity using a conservatively treated group (n=1748) as a control. Baseline BMI in surgical group (42.2+/-4.4 kg/m(2)) and control group (40.1+/-4.6 kg/m(2)) changed -9.7+/-5 kg/m(2) and 0+/-3 kg/m(2), respectively, at 2-year follow-up. In the surgery group, there was a marked improvement in all obstructive sleep apnea (OSA) symptoms compared with the control group (P sleep apnea symptoms at 2 years. Despite adjustment for weight change and baseline central obesity, subjects reporting loss of OSA symptoms had a lower 2-year incidence of diabetes and hypertriglyceridemia. Improvement in OSA in patients losing weight may provide health benefits in addition to weight loss alone.

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

    Directory of Open Access Journals (Sweden)

    Vaughn BV

    2014-09-01

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

  15. Can High Altitude Influence Cytokines and Sleep?

    Directory of Open Access Journals (Sweden)

    Valdir de Aquino Lemos

    2013-01-01

    Full Text Available The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2 induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β, Interleukin-6 (IL-6, and tumor necrosis factor-alpha (TNF-α production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.

  16. Can High Altitude Influence Cytokines and Sleep?

    Science.gov (United States)

    de Aquino Lemos, Valdir; dos Santos, Ronaldo Vagner Thomatieli; Lira, Fabio Santos; Rodrigues, Bruno; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain. PMID:23690660

  17. Systematic review: the influence of nasal obstruction on sleep apnea

    Directory of Open Access Journals (Sweden)

    Debora Petrungaro Migueis

    2016-04-01

    Full Text Available ABSTRACT INTRODUCTION: Obstructive sleep apnea syndrome (OSAS is a common disorder that can lead to cardiovascular morbidity and mortality, as well as to metabolic, neurological, and behavioral consequences. It is currently believed that nasal obstruction compromises the quality of sleep when it results in breathing disorders and fragmentation of sleep. However, recent studies have failed to objectively associate sleep quality and nasal obstruction. OBJECTIVE: The aim of this systematic review is to evaluate the influence of nasal obstruction on OSAS and polysomnographic indices associated with respiratory events. METHODS: Eleven original articles published from 2003 to 2013 were selected, which addressed surgical and non-surgical treatment for nasal obstruction, performing polysomnography type 1 before and after the intervention. RESULTS/CONCLUSIONS: In most trials, nasal obstruction was not related to the apnea-hypopnea index (AHI, indicating no improvement in OSAS with reduction in nasal resistance. However, few researchers evaluated other polysomnography indices, such as the arousal index and rapid eye movement (REM sleep percentage. These could change with nasal obstruction, since it is possible that the nasal obstruction does not completely block the upper airways, but can increase negative intrathoracic pressure, leading to sleep fragmentation.

  18. Systematic review: the influence of nasal obstruction on sleep apnea.

    Science.gov (United States)

    Migueis, Debora Petrungaro; Thuler, Luiz Claudio Santos; Lemes, Lucas Neves de Andrade; Moreira, Chirlene Santos Souza; Joffily, Lucia; Araujo-Melo, Maria Helena de

    2016-01-01

    Obstructive sleep apnea syndrome (OSAS) is a common disorder that can lead to cardiovascular morbidity and mortality, as well as to metabolic, neurological, and behavioral consequences. It is currently believed that nasal obstruction compromises the quality of sleep when it results in breathing disorders and fragmentation of sleep. However, recent studies have failed to objectively associate sleep quality and nasal obstruction. The aim of this systematic review is to evaluate the influence of nasal obstruction on OSAS and polysomnographic indices associated with respiratory events. Eleven original articles published from 2003 to 2013 were selected, which addressed surgical and non-surgical treatment for nasal obstruction, performing polysomnography type 1 before and after the intervention. In most trials, nasal obstruction was not related to the apnea-hypopnea index (AHI), indicating no improvement in OSAS with reduction in nasal resistance. However, few researchers evaluated other polysomnography indices, such as the arousal index and rapid eye movement (REM) sleep percentage. These could change with nasal obstruction, since it is possible that the nasal obstruction does not completely block the upper airways, but can increase negative intrathoracic pressure, leading to sleep fragmentation. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  19. Upregulation of gene expression in reward-modulatory striatal opioid systems by sleep loss.

    Science.gov (United States)

    Baldo, Brian A; Hanlon, Erin C; Obermeyer, William; Bremer, Quentin; Paletz, Elliott; Benca, Ruth M

    2013-12-01

    Epidemiological studies have shown a link between sleep loss and the obesity 'epidemic,' and several observations indicate that sleep curtailment engenders positive energy balance via increased palatable-food 'snacking.' These effects suggest alterations in reward-modulatory brain systems. We explored the effects of 10 days of sleep deprivation in rats on the expression of striatal opioid peptide (OP) genes that subserve food motivation and hedonic reward, and compared effects with those seen in hypothalamic energy balance-regulatory systems. Sleep-deprived (Sleep-Dep) rats were compared with yoked forced-locomotion apparatus controls (App-Controls), food-restricted rats (Food-Restrict), and unmanipulated controls (Home-Cage). Detection of mRNA levels with in situ hybridization revealed a subregion-specific upregulation of striatal preproenkephalin and prodynorhin gene expression in the Sleep-Dep group relative to all other groups. Neuropeptide Y (NPY) gene expression in the hippocampal dentate gyrus and throughout neocortex was also robustly upregulated selectively in the Sleep-Dep group. In contrast, parallel gene expression changes were observed in the Sleep-Dep and Food-Restrict groups in hypothalamic energy-sensing systems (arcuate nucleus NPY was upregulated, and cocaine- and amphetamine-regulated transcript was downregulated), in alignment with leptin suppression in both groups. Together, these results reveal a novel set of sleep deprivation-induced transcriptional changes in reward-modulatory peptide systems, which are dissociable from the energy-balance perturbations of sleep loss or the potentially stressful effects of the forced-locomotion procedure. The recruitment of telencephalic food-reward systems may provide a feeding drive highly resistant to feedback control, which could engender obesity through the enhancement of palatable feeding.

  20. Astrocytic Modulation of Sleep Homeostasis and Cognitive Consequences of Sleep Loss

    OpenAIRE

    Halassa, Michael M.; Florian, Cedrick; Fellin, Tommaso; Munoz, James R.; Lee, So-Young; Abel, Ted; Haydon, Philip G.; Frank, Marcos G.

    2009-01-01

    Astrocytes modulate neuronal activity by releasing chemical transmitters via a process termed gliotransmission. The role of this process in the control of behavior is unknown. Since one outcome of SNARE-dependent gliotransmission is the regulation of extracellular adenosine and because adenosine promotes sleep, we genetically inhibited the release of gliotransmitters and asked if astrocytes play an unsuspected role in sleep regulation. Inhibiting gliotransmission attenuated the accumulation o...

  1. What drives sleep-dependent memory consolidation: greater gain or less loss?

    Science.gov (United States)

    Fenn, Kimberly M; Hambrick, David Z

    2013-06-01

    When memory is tested after a delay, performance is typically better if the retention interval includes sleep. However, it is unclear what accounts for this well-established effect. It is possible that sleep enhances the retrieval of information, but it is also possible that sleep protects against memory loss that normally occurs during waking activity. We developed a new research approach to investigate these possibilities. Participants learned a list of paired-associate items and were tested on the items after a 12-h interval that included waking or sleep. We analyzed the number of items gained versus the number of items lost across time. The sleep condition showed more items gained and fewer items lost than did the wake condition. Furthermore, the difference between the conditions (favoring sleep) in lost items was greater than the difference in gain, suggesting that loss prevention may primarily account for the effect of sleep on declarative memory consolidation. This finding may serve as an empirical constraint on theories of memory consolidation.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Chronotype influences activity circadian rhythm and sleep: differences in sleep quality between weekdays and weekend.

    Science.gov (United States)

    Vitale, Jacopo A; Roveda, Eliana; Montaruli, Angela; Galasso, Letizia; Weydahl, Andi; Caumo, Andrea; Carandente, Franca

    2015-04-01

    Several studies have shown the differences among chronotypes in the circadian rhythm of different physiological variables. Individuals show variation in their preference for the daily timing of activity; additionally, there is an association between chronotype and sleep duration/sleep complaints. Few studies have investigated sleep quality during the week days and weekends in relation to the circadian typology using self-assessment questionnaires or actigraphy. The purpose of this study was to use actigraphy to assess the relationship between the three chronotypes and the circadian rhythm of activity levels and to determine whether sleep parameters respond differently with respect to time (weekdays versus the weekend) in Morning-types (M-types), Neither-types (N-types) and Evening-types (E-types). The morningness-eveningness questionnaire (MEQ) was administered to 502 college students to determine their chronotypes. Fifty subjects (16 M-types, 15 N-types and 19 E-types) were recruited to undergo a 7-days monitoring period with an actigraph (Actiwacth® actometers, CNT, Cambridge, UK) to evaluate their sleep parameters and the circadian rhythm of their activity levels. To compare the amplitude and the acrophase among the three chronotypes, we used a one-way ANOVA followed by the Tukey-Kramer post-hoc test. To compare the Midline Estimating Statistic of Rhythm (MESOR) among the three chronotypes, we used a Kruskal-Wallis non-parametric test followed by pairwise comparisons that were performed using Dunn's procedure with a Bonferroni correction for multiple comparisons. The analysis of each sleep parameter was conducted using the mixed ANOVA procedure. The results showed that the chronotype was influenced by sex (χ(2) with p = 0.011) and the photoperiod at birth (χ(2) with p circadian rhythm of activity levels was influenced by the chronotype; second, the chronotype had a significant effect on sleep parameters: the E-types had a reduced sleep quality and

  4. Can a mathematical model predict an individual's trait-like response to both total and partial sleep loss?

    Science.gov (United States)

    Ramakrishnan, Sridhar; Lu, Wei; Laxminarayan, Srinivas; Wesensten, Nancy J; Rupp, Tracy L; Balkin, Thomas J; Reifman, Jaques

    2015-06-01

    Humans display a trait-like response to sleep loss. However, it is not known whether this trait-like response can be captured by a mathematical model from only one sleep-loss condition to facilitate neurobehavioural performance prediction of the same individual during a different sleep-loss condition. In this paper, we investigated the extent to which the recently developed unified mathematical model of performance (UMP) captured such trait-like features for different sleep-loss conditions. We used the UMP to develop two sets of individual-specific models for 15 healthy adults who underwent two different sleep-loss challenges (order counterbalanced; separated by 2-4 weeks): (i) 64 h of total sleep deprivation (TSD) and (ii) chronic sleep restriction (CSR) of 7 days of 3 h nightly time in bed. We then quantified the extent to which models developed using psychomotor vigilance task data under TSD predicted performance data under CSR, and vice versa. The results showed that the models customized to an individual under one sleep-loss condition accurately predicted performance of the same individual under the other condition, yielding, on average, up to 50% improvement over non-individualized, group-average model predictions. This finding supports the notion that the UMP captures an individual's trait-like response to different sleep-loss conditions. © 2014 European Sleep Research Society.

  5. Sex hormones play a role in vulnerability to sleep loss on emotion processing tasks

    Directory of Open Access Journals (Sweden)

    K.A. Lustig

    2018-06-01

    Full Text Available The central aim of this study was to investigate hormones as a predictor of individual vulnerability or resiliency on emotion processing tasks following one night of sleep restriction. The restriction group was instructed to sleep 3 a.m.–7 a.m. (13 men, 13 women in follicular phase, 10 women in luteal phase of menstrual cycle, and a control group slept 11 p.m.–7 a.m. (12 men, 12 follicular women, 12 luteal women. Sleep from home was verified with actigraphy. Saliva samples were collected on the evening prior to restriction, and in the morning and afternoon following restriction, to measure testosterone, estradiol, and progesterone. In the laboratory, event-related potentials (ERPs were recorded during presentation of images and faces to index neural processing of emotional stimuli. Compared to controls, sleep-restricted participants had a larger amplitude Late Positive Potential (LPP ERP to positive vs neutral images, reflecting greater motivated attention towards positive stimuli. Sleep-restricted participants were also less accurate categorizing sad faces and exhibited a larger N170 to sad faces, reflecting greater neural reactivity. Sleep-restricted luteal women were less accurate categorizing all images compared to control luteal women, and progesterone was related to several outcomes. Morning testosterone in men was lower in the sleep-restricted group compared to controls; lower testosterone was associated with lower accuracy to positive images, a greater difference between positive vs neutral LPP amplitude, and lower accuracy to sad and fearful faces. In summary, women higher in progesterone and men lower in testosterone were more vulnerable to the effects of sleep restriction on emotion processing tasks. This study highlights a role for sex and sex hormones in understanding individual differences in vulnerability to sleep loss. Keywords: Sleep restriction, Emotion processing, Testosterone, Progesterone, Estradiol

  6. Distinct effects of acute and chronic sleep loss on DNA damage in rats.

    Science.gov (United States)

    Andersen, M L; Ribeiro, D A; Bergamaschi, C T; Alvarenga, T A; Silva, A; Zager, A; Campos, R R; Tufik, S

    2009-04-30

    The aim of this investigation was to evaluate genetic damage induced in male rats by experimental sleep loss for short-term (24 and 96 h) and long-term (21 days) intervals, as well as their respective recovery periods in peripheral blood, brain, liver and heart tissue by the single cell gel (comet) assay. Rats were paradoxically deprived of sleep (PSD) by the platform technique for 24 or 96 h, or chronically sleep-restricted (SR) for 21 days. We also sought to verify the time course of their recovery after 24 h of rebound sleep. The results showed DNA damage in blood cells of rats submitted to PSD for 96 h. Brain tissue showed extensive genotoxic damage in PSD rats (both 24 and 96 h), though the effect was more pronounced in the 96 h group. Rats allowed to recover from the PSD-96 h and SR-21 days treatments showed DNA damage as compared to negative controls. Liver and heart did not display any genotoxicity activity. Corticosterone concentrations were increased after PSD (24 and 96 h) relative to control rats, whereas these levels were unaffected in the SR group. Collectively, these findings reveal that sleep loss was able to induce genetic damage in blood and brain cells, especially following acute exposure. Since DNA damage is an important step in events leading to genomic instability, this study represents a relevant contribution to the understanding of the potential health risks associated with sleep deprivation.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Cocaine potentiates ketamine-induced loss of the righting reflex and sleeping time in mice. Role of catecholamines.

    Science.gov (United States)

    Vanderwende, C; Spoerlein, M T; Lapollo, J

    1982-07-01

    Cocaine in graded doses potentiated ketamine-induced loss of the righting reflex and sleeping time. Potentiation of drug-induced sleep with cocaine was not a generalized phenomenon inasmuch as it had no effect on sleep induced by pentobarbital or hexobarbital and decreased sleep induced by phenobarbital. Pentylenetetrazole reduced ketamine sleep but d-amphetamine had a potentiative action. dl-alpha-Methyl-p-tyrosine methyl ester itself increased both the number losing the righting reflex and the sleeping time induced by ketamine. However, the effect cocaine on sleeping time was blocked 3 h after the dl-alpha-methyl-p-tyrosine methyl ester was given. The alpha and beta adrenergic blocking drugs, phenoxybenzamine and propranolol, increased the number of animals losing the righting reflex with ketamine, and phenoxybenzamine lengthened the sleeping time. Alpha and beta adrenergic agonists, l-phenylephrine and isoproterenol, increased the number of animals going to sleep with ketamine but did not significantly alter how long they would sleep. The agonists had no effect on the cocaine interaction with ketamine, whereas the antagonists blocked the effect of cocaine. Both stimulation and blockade of dopamine receptors led to increased loss of the righting reflex and sleeping time with ketamine but only receptor blockade antagonized the effect of cocaine on ketamine-induced sleep. Thus, both the noradrenergic and dopaminergic systems appear to be involved in the ability of cocaine to potentiate ketamine-induced sleep.

  9. Sleep Extension before Sleep Loss: Effects on Performance and Neuromuscular Function.

    Science.gov (United States)

    Arnal, Pierrick J; Lapole, Thomas; Erblang, Mégane; Guillard, Mathias; Bourrilhon, Cyprien; Léger, Damien; Chennaoui, Mounir; Millet, Guillaume Y

    2016-08-01

    This study aimed to investigate the effects of six nights of sleep extension on motor performance and associated neuromuscular function before and after one night of total sleep deprivation (TSD). Twelve healthy men participated in two experimental conditions (randomized crossover design): extended sleep (EXT, 9.8 ± 0.1 h time in bed) and habitual sleep (HAB, 8.2 ± 0.1 h time in bed). In each condition, subjects performed six nights of either EXT or HAB at home followed by an assessment of motor performance and neuromuscular function at baseline (D0) and after one night of TSD, i.e., 34-37 h of continuous wakefulness (D1). Maximal voluntary contractions with superimposed femoral nerve electrical and transcranial magnetic stimulations and stimulations on relaxed muscles were investigated before and after submaximal isometric knee extensor exercises performed until task failure. Time to exhaustion was longer in EXT compared with HAB (+3.9% ± 7.7% and +8.1% ± 12.3% at D0 and D1, respectively). Performance at D1 decreased from D0 similarly between conditions (-7.2% ± 5.6% and -3.7% ± 7.3% in HAB and EXT, respectively). At D1, the RPE during exercise was lower in EXT compared with HAB (-7.2% ± 7.5%) with no difference at D0. No difference was observed in voluntary activation between the two conditions. Six nights of sleep extension improved sustained contraction time to exhaustion, and this result cannot be explained by smaller reductions in voluntary activation, measured by both nerve and transcranial magnetic stimulation. The beneficial effect on motor performance in the EXT condition was likely due to reduced RPE after TSD.

  10. The influence of continuous and intermittent traffic noise on sleep

    Science.gov (United States)

    Eberhardt, J. L.; Stråle, L.-O.; Berlin, M. H.

    1987-08-01

    The effects of road traffic noise on sleep were studied in the laboratory using nine young male adults (aged 20-26). The subjects were exposed to noise with different temporal characteristics: (i) continuous traffic noise of 36 dB(A) or 45 dB(A), (ii) intermittent noise of 50 truck passages with L pmax = 45 dB(A) ( L eq = 29 dB(A)) or L pmax = 55 dB(A) ( L eq = 36 dB(A)), and (iii) a combination of continuous (45 dB(A)) and intermittent ( L pmax = 55 dB(A)) traffic noise. For one noise condition (intermittent 55 dB(A)) the effect of the use of ear plugs was also studied. The intermittent noise of L pmax = 45 dB(A) caused transitions towards lighter sleep, whereas 55 dB(A) was needed to induce awakening effects. It could be shown that the probability for arousal reactions depends on the emergence of the noise peaks from the background, rather than the absolute noise peak level. Continuous traffic noise of 45 dB(A) caused REM sleep deficits, while intermittent traffic noise of L pmax = 45 dB(A) caused stage III+IV deficits. The night with ear plugs was virtually undisturbed. After nights with REM sleep deficits the subjective sleep quality was rated lower and mood was influenced adversely. For the types of exposure used in the present investigation L eq alone is not an adequate descriptor of the noise dose, relating to the sleep disturbances observed. From the present experiment, together with other existing data, it might be concluded that the WHO recommendation of L eq = 35 dB(A) is adequate, but should be supplemented with a maximum noise level, as expressed for example in L pmax or LI, that should not be exceeded.

  11. Weight loss alters severity of individual nocturnal respiratory events depending on sleeping position

    International Nuclear Information System (INIS)

    Kulkas, A; Leppänen, T; Tiihonen, P; Mervaala, E; Töyräs, J; Sahlman, J; Seppä, J; Kokkarinen, J; Randell, J; Tuomilehto, H

    2014-01-01

    Weight loss is an effective treatment for obstructive sleep apnea (OSA). The mechanisms of how weight loss affects nocturnal breathing are not fully understood. The severity of OSA is currently estimated by the number of respiratory events per hour of sleep (i.e. apnea-hypopnea-index, AHI). AHI neglects duration and morphology of individual respiratory events, which describe the severity of individual events. In the current paper, we investigate the novel Adjusted-AHI parameter (incorporating individual event severity) and AHI after weight loss in relation to sleeping position. It was hypothesised that there are positional differences in individual event severity changes during weight loss. Altogether, 32 successful (> 5% of weight) and 34 unsuccessful weight loss patients at baseline and after 1 year follow-up were analysed. The results revealed that individual respiratory event severity was reduced differently in supine and non-supine positions during weight loss. During weight loss, AHI was reduced by 54% (p = 0.004) and 74% (p < 0.001), while Adjusted-AHI was reduced by 14% (p = 0.454) and 48% (p = 0.003) in supine and non-supine positions, respectively. In conclusion, the severity of individual respiratory events decreased more in the non-supine position. The novel Adjusted-AHI parameter takes these changes into account and might therefore contribute additional information to the planning of treatment of OSA patients. (paper)

  12. A single night of sleep loss impairs objective but not subjective working memory performance in a sex-dependent manner.

    Science.gov (United States)

    Rångtell, Frida H; Karamchedu, Swathy; Andersson, Peter; Liethof, Lisanne; Olaya Búcaro, Marcela; Lampola, Lauri; Schiöth, Helgi B; Cedernaes, Jonathan; Benedict, Christian

    2018-01-31

    Acute sleep deprivation can lead to judgement errors and thereby increases the risk of accidents, possibly due to an impaired working memory. However, whether the adverse effects of acute sleep loss on working memory are modulated by auditory distraction in women and men are not known. Additionally, it is unknown whether sleep loss alters the way in which men and women perceive their working memory performance. Thus, 24 young adults (12 women using oral contraceptives at the time of investigation) participated in two experimental conditions: nocturnal sleep (scheduled between 22:30 and 06:30 hours) versus one night of total sleep loss. Participants were administered a digital working memory test in which eight-digit sequences were learned and retrieved in the morning after each condition. Learning of digital sequences was accompanied by either silence or auditory distraction (equal distribution among trials). After sequence retrieval, each trial ended with a question regarding how certain participants were of the correctness of their response, as a self-estimate of working memory performance. We found that sleep loss impaired objective but not self-estimated working memory performance in women. In contrast, both measures remained unaffected by sleep loss in men. Auditory distraction impaired working memory performance, without modulation by sleep loss or sex. Being unaware of cognitive limitations when sleep-deprived, as seen in our study, could lead to undesirable consequences in, for example, an occupational context. Our findings suggest that sleep-deprived young women are at particular risk for overestimating their working memory performance. © 2018 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

  13. Sleep deprivation accelerates delay-related loss of visual short-term memories without affecting precision.

    Science.gov (United States)

    Wee, Natalie; Asplund, Christopher L; Chee, Michael W L

    2013-06-01

    Visual short-term memory (VSTM) is an important measure of information processing capacity and supports many higher-order cognitive processes. We examined how sleep deprivation (SD) and maintenance duration interact to influence the number and precision of items in VSTM using an experimental design that limits the contribution of lapses at encoding. For each trial, participants attempted to maintain the location and color of three stimuli over a delay. After a retention interval of either 1 or 10 seconds, participants reported the color of the item at the cued location by selecting it on a color wheel. The probability of reporting the probed item, the precision of report, and the probability of reporting a nonprobed item were determined using a mixture-modeling analysis. Participants were studied twice in counterbalanced order, once after a night of normal sleep and once following a night of sleep deprivation. Sleep laboratory. Nineteen healthy college age volunteers (seven females) with regular sleep patterns. Approximately 24 hours of total SD. SD selectively reduced the number of integrated representations that can be retrieved after a delay, while leaving the precision of object information in the stored representations intact. Delay interacted with SD to lower the rate of successful recall. Visual short-term memory is compromised during sleep deprivation, an effect compounded by delay. However, when memories are retrieved, they tend to be intact.

  14. Treatment for snoring. Combined weight loss, sleeping on side, and nasal spray.

    Science.gov (United States)

    Braver, H M; Block, A J; Perri, M G

    1995-05-01

    We sought to find a combination of noninvasive treatments for snoring by adding weight loss to previously studied treatments, including the combination of sleeping on one's side and using a decongestant nasal spray. Twenty asymptomatic men who snore heavily were studied previously on a control night and on a night when they slept on their side and used a nasal spray. With these two treatments, minor improvements in apnea/hypopnea index (AHI) were seen, but no improvement occurred in snoring frequency. Nineteen of these subjects subsequently completed a 6-month weight loss program, and 12 lost weight. These 19 subjects comprise the study population of this report. At the conclusion of the weight loss program, a repeated sleep study was done from which the effect of adding weight loss to the two previously studied treatments could be assessed. Those 12 subjects who lost any amount of weight showed a very mild reduction in snores per hour from 328 using two modalities of treatment to 232 per hour with the addition of weight loss (p = 0.15). The nine subjects who lost > or = 3 kg reduced the number of snores per hour from 320 to 176 (p = 0.0496). Three subjects losing an average of only 7.6 kg showed virtual elimination of snoring after weight loss. Subjects who gained weight had no improvement in snoring. Weight loss added to the other two modalities of treatment had no effect on the AHI. In most cases, the combination of weight loss, sleeping on one's side, and the administration of a nasal decongestant significantly reduces the frequency of snoring in asymptomatic men who snore heavily. The major effect appears to be related to weight loss.

  15. Sleep-wake patterns and their influence on school performance in Portuguese adolescents.

    Science.gov (United States)

    Duarte, João; Nelas, Paula; Chaves, Cláudia; Ferreira, Manuela; Coutinho, Emília; Cunha, Madalena

    2014-11-01

    To characterise sleep-wake patterns and their influence on academic performance for a sample of Portuguese adolescents. Cross-sectional, analytical-explanatory, correlational epidemiological research. The protocol includes the composite morningness questionnaire (Barton et al, 1985 adapted by Silva et al, 1985), the Epworth Sleepiness Scale (Murray, 1991), chronic fatigue scale (Smith et al, 1995), the Pittsburgh Sleep Quality Index (Buysse, 1988), Educational Achievement (Fermin, 2005), personal and academic data. 2094 students (55.3% girls; 16-23 years old; M=16.82±1.25) attending secondary school in central Portugal. Living in urban areas, living with their parents and about 57.1% are in a family with reasonable economic resources. Adolescents' sleep patterns reveal that they sleep on average between 8-9 hours a night, do not use medication to sleep, with sleep latency within the normal range, with good sleep efficiency, without daytime dysfunction and with undisturbed sleep, predominantly intermediate chronotype. Minor drowsiness, increased sleep efficiency, improved subjective sleep satisfaction, less sleep disturbance, less daytime dysfunction, not consuming hypnotic medications, associated with better academic performance. Morningness/eveningness, sleep efficiency, daytime dysfunction and sleep latency emerge as predictors of academic performance. The chronotype interacts to predict the quality of sleep enhancing it as a mediator of school performance. Sleep and associated individual characteristics should be considered in the diagnosis and intervention process in secondary education. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  16. Computational cognitive modeling of the temporal dynamics of fatigue from sleep loss.

    Science.gov (United States)

    Walsh, Matthew M; Gunzelmann, Glenn; Van Dongen, Hans P A

    2017-12-01

    Computational models have become common tools in psychology. They provide quantitative instantiations of theories that seek to explain the functioning of the human mind. In this paper, we focus on identifying deep theoretical similarities between two very different models. Both models are concerned with how fatigue from sleep loss impacts cognitive processing. The first is based on the diffusion model and posits that fatigue decreases the drift rate of the diffusion process. The second is based on the Adaptive Control of Thought - Rational (ACT-R) cognitive architecture and posits that fatigue decreases the utility of candidate actions leading to microlapses in cognitive processing. A biomathematical model of fatigue is used to control drift rate in the first account and utility in the second. We investigated the predicted response time distributions of these two integrated computational cognitive models for performance on a psychomotor vigilance test under conditions of total sleep deprivation, simulated shift work, and sustained sleep restriction. The models generated equivalent predictions of response time distributions with excellent goodness-of-fit to the human data. More importantly, although the accounts involve different modeling approaches and levels of abstraction, they represent the effects of fatigue in a functionally equivalent way: in both, fatigue decreases the signal-to-noise ratio in decision processes and decreases response inhibition. This convergence suggests that sleep loss impairs psychomotor vigilance performance through degradation of the quality of cognitive processing, which provides a foundation for systematic investigation of the effects of sleep loss on other aspects of cognition. Our findings illustrate the value of treating different modeling formalisms as vehicles for discovery.

  17. The effects of 72 hours of sleep loss on psychological variables.

    Science.gov (United States)

    Mikulincer, M; Babkoff, H; Caspy, T; Sing, H

    1989-05-01

    A study was conducted on the effects of 72 hours of sleep loss and modified continuous operations on performance and psychological variables. This paper presents the results of self-report data of 12 subjects for the following psychological variables: sleepiness, affect, motivation, cognitive difficulties, and waking dreams. The relationship between the self-report measures and performance in a visual search and memory task is also examined. Most of the psychological variables are significantly affected by the number of days of sleep deprivation, all are significantly affected by hour of day; but only sleepiness, affect and motivation are also significantly affected by the interaction between these variables. The peak hours for self-reported psychological complaints are generally between 0400 and 0800, while the lowest number of complaints are usually reported in the afternoon/early evening, between 1600 and 2000. In addition, the results showed that (a) the amplitude of the circadian component of the psychological data increased over the period of sleep loss, and (b) psychological data were more highly correlated with a measure of general performance than with accuracy. The mechanisms of sleep deprivation underlying its effects on psychological and performance measures are discussed.

  18. Sleep

    Science.gov (United States)

    ... Institute (NHLBI). 1 Mood. Sleep affects your mood. Insufficient sleep can cause irritability that can lead to trouble with relationships, ... basics/understanding_sleep.htm#dynamic_activity Centers for Disease ... insufficient rest or sleep among adults—United States, 2008. MMWR, 58 (42), ...

  19. Gratitude influences sleep through the mechanism of pre-sleep cognitions.

    Science.gov (United States)

    Wood, Alex M; Joseph, Stephen; Lloyd, Joanna; Atkins, Samuel

    2009-01-01

    To test whether individual differences in gratitude are related to sleep after controlling for neuroticism and other traits. To test whether pre-sleep cognitions are the mechanism underlying this relationship. A cross-sectional questionnaire study was conducted with a large (186 males, 215 females) community sample (ages=18-68 years, mean=24.89, S.D.=9.02), including 161 people (40%) scoring above 5 on the Pittsburgh Sleep Quality Index, indicating clinically impaired sleep. Measures included gratitude, the Pittsburgh Sleep Quality Index (PSQI), self-statement test of pre-sleep cognitions, the Mini-IPIP scales of Big Five personality traits, and the Social Desirability Scale. Gratitude predicted greater subjective sleep quality and sleep duration, and less sleep latency and daytime dysfunction. The relationship between gratitude and each of the sleep variables was mediated by more positive pre-sleep cognitions and less negative pre-sleep cognitions. All of the results were independent of the effect of the Big Five personality traits (including neuroticism) and social desirability. This is the first study to show that a positive trait is related to good sleep quality above the effect of other personality traits, and to test whether pre-sleep cognitions are the mechanism underlying the relationship between any personality trait and sleep. The study is also the first to show that trait gratitude is related to sleep and to explain why this occurs, suggesting future directions for research, and novel clinical implications.

  20. Serum Amyloid A Production Is Triggered by Sleep Deprivation in Mice and Humans: Is That the Link between Sleep Loss and Associated Comorbidities?

    Science.gov (United States)

    de Oliveira, Edson M.; Visniauskas, Bruna; Tufik, Sergio; Andersen, Monica L.; Chagas, Jair R.; Campa, Ana

    2017-01-01

    Serum amyloid A (SAA) was recently associated with metabolic endotoxemia, obesity and insulin resistance. Concurrently, insufficient sleep adversely affects metabolic health and is an independent predisposing factor for obesity and insulin resistance. In this study we investigated whether sleep loss modulates SAA production. The serum SAA concentration increased in C57BL/6 mice subjected to sleep restriction (SR) for 15 days or to paradoxical sleep deprivation (PSD) for 72 h. Sleep restriction also induced the upregulation of Saa1.1/Saa2.1 mRNA levels in the liver and Saa3 mRNA levels in adipose tissue. SAA levels returned to the basal range after 24 h in paradoxical sleep rebound (PSR). Metabolic endotoxemia was also a finding in SR. Increased plasma levels of SAA were also observed in healthy human volunteers subjected to two nights of total sleep deprivation (Total SD), returning to basal levels after one night of recovery. The observed increase in SAA levels may be part of the initial biochemical alterations caused by sleep deprivation, with potential to drive deleterious conditions such as metabolic endotoxemia and weight gain. PMID:28335560

  1. Effects of night work, sleep loss and time on task on simulated threat detection performance.

    Science.gov (United States)

    Basner, Mathias; Rubinstein, Joshua; Fomberstein, Kenneth M; Coble, Matthew C; Ecker, Adrian; Avinash, Deepa; Dinges, David F

    2008-09-01

    To investigate the effects of night work and sleep loss on a simulated luggage screening task (SLST) that mimicked the x-ray system used by airport luggage screeners. We developed more than 5,800 unique simulated x-ray images of luggage organized into 31 stimulus sets of 200 bags each. 25% of each set contained either a gun or a knife with low or high target difficulty. The 200-bag stimuli sets were then run on software that simulates an x-ray screening system (SLST). Signal detection analysis was used to obtain measures of hit rate (HR), false alarm rate (FAR), threat detection accuracy (A'), and response bias (B"(D)). Experimental laboratory study 24 healthy nonprofessional volunteers (13 women, mean age +/- SD = 29.9 +/- 6.5 years). Subjects performed the SLST every 2 h during a 5-day period that included a 35 h period of wakefulness that extended to night work and then another day work period after the night without sleep. Threat detection accuracy A' decreased significantly (P work, while both A' (P = 0.001) and HR decreased (P = 0.008) during day work following sleep loss. There were prominent time-on-task effects on response bias B"(D) (P= 0.002) and response latency (P = 0.004), but accuracy A' was unaffected. Both HR and FAR increased significantly with increasing study duration (both P work and sleep loss adversely affect the accuracy of detecting complex real world objects among high levels of background clutter. If the results can be replicated in professional screeners and real work environments, fatigue in luggage screening personnel may pose a threat for air traffic safety unless countermeasures for fatigue are deployed.

  2. Sleep loss and acute drug abuse can induce DNA damage in multiple organs of mice.

    Science.gov (United States)

    Alvarenga, T A; Ribeiro, D A; Araujo, P; Hirotsu, C; Mazaro-Costa, R; Costa, J L; Battisti, M C; Tufik, S; Andersen, M L

    2011-09-01

    The purpose of the present study was to characterize the genetic damage induced by paradoxical sleep deprivation (PSD) in combination with cocaine or ecstasy (3,4-methylenedioxymethamphetamine; MDMA) in multiple organs of male mice using the single cell gel (comet) assay. C57BL/6J mice were submitted to PSD by the platform technique for 72 hours, followed by drug administration and evaluation of DNA damage in peripheral blood, liver and brain tissues. Cocaine was able to induce genetic damage in the blood, brain and liver cells of sleep-deprived mice at the majority of the doses evaluated. Ecstasy also induced increased DNA migration in peripheral blood cells for all concentrations tested. Analysis of damaged cells by the tail moment data suggests that ecstasy is a genotoxic chemical at the highest concentrations tested, inducing damage in liver or brain cells after sleep deprivation in mice. Taken together, our results suggest that cocaine and ecstasy/MDMA act as potent genotoxins in multiple organs of mice when associated with sleep loss.

  3. Chronotype, sleep loss, and diurnal pattern of salivary cortisol in a simulated daylong driving.

    Science.gov (United States)

    Oginska, Halszka; Fafrowicz, Magdalena; Golonka, Krystyna; Marek, Tadeusz; Mojsa-Kaja, Justyna; Tucholska, Kinga

    2010-07-01

    distinct diurnal variation (F = 2.950, p < .019), whereas E types showed a flattened diurnal curve. Cortisol values did not correlate with subjective assessments of workload, arousal, or sleepiness at any time-of-day. Diurnal cortisol pattern parameters (i.e., morning level, mean level, and range of diurnal changes) showed significant positive correlations with sleep length before the experiment (r = .48, .54, and .53, respectively) and with sleep index (r = .63, .64, and .56, respectively). The conclusions of this study are: (i) E-oriented types showed lower salivary cortisol levels and a flattened diurnal curve in comparison with M types; (ii) sleep loss was associated with lower morning cortisol and mean diurnal level, whereas higher cortisol levels were observed in rested individuals. In the context of stress theory, it may be hypothesized that rested subjects perceived the driving task as a challenge, whereas those with reduced sleep were not challenged, but bored/exhausted with the experimental situation.

  4. Sleep Deprivation Influences Circadian Gene Expression in the Lateral Habenula.

    Science.gov (United States)

    Zhang, Beilin; Gao, Yanxia; Li, Yang; Yang, Jing; Zhao, Hua

    2016-01-01

    Sleep is governed by homeostasis and the circadian clock. Clock genes play an important role in the generation and maintenance of circadian rhythms but are also involved in regulating sleep homeostasis. The lateral habenular nucleus (LHb) has been implicated in sleep-wake regulation, since LHb gene expression demonstrates circadian oscillation characteristics. This study focuses on the participation of LHb clock genes in regulating sleep homeostasis, as the nature of their involvement is unclear. In this study, we observed changes in sleep pattern following sleep deprivation in LHb-lesioned rats using EEG recording techniques. And then the changes of clock gene expression (Per1, Per2, and Bmal1) in the LHb after 6 hours of sleep deprivation were detected by using real-time quantitative PCR (qPCR). We found that sleep deprivation increased the length of Non-Rapid Eye Movement Sleep (NREMS) and decreased wakefulness. LHb-lesioning decreased the amplitude of reduced wake time and increased NREMS following sleep deprivation in rats. qPCR results demonstrated that Per2 expression was elevated after sleep deprivation, while the other two genes were unaffected. Following sleep recovery, Per2 expression was comparable to the control group. This study provides the basis for further research on the role of LHb Per2 gene in the regulation of sleep homeostasis.

  5. Effects of a Two-Year Behavioral Weight Loss Intervention on Sleep and Mood in Obese Individuals Treated in Primary Care Practice

    OpenAIRE

    Alfaris, Nasreen; Wadden, Thomas A.; Sarwer, David B; Diwald, Lisa; Volger, Sheri; Hong, Patricia; Baxely, Amber; Minnick, Alyssa M.; Vetter, Marion L.; Berkowitz, Robert I.; Chittams, Jesse

    2015-01-01

    Objective To examine the effect of weight loss on sleep duration, sleep quality, and mood in 390 obese men and women who received one of three behavioral weight loss intervention in the Practice-based Opportunities for Weight Reduction trial at the University of Pennsylvania (POWER-UP). Methods Sleep duration and quality were assessed at baseline and months 6 and 24 by the Pittsburgh Sleep Quality Index (PSQI) questionnaire and mood by the Patient Health Questionnaire-8 (PHQ-8). Changes in sl...

  6. The influence of school time on sleep patterns of children and adolescents.

    Science.gov (United States)

    Carissimi, Alicia; Dresch, Fabiane; Martins, Alessandra Castro; Levandovski, Rosa Maria; Adan, Ana; Natale, Vincenzo; Martoni, Monica; Hidalgo, Maria Paz

    2016-03-01

    This epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents. This cross-sectional study involved 639 elementary and high school students (mean age 13.03 years, range 8-18, 58.5% female) from the south of Brazil. Participants answered the Morningness-Eveningness Questionnaire (MEQ), and were asked about their sleeping habits on weekdays and weekends. Sleep deficit was defined as the difference between sleep duration on weekdays and weekends. The morning-school-time students presented significantly higher age, bedtime and wake up differences, sleep deficits, and social jetlag. The sleep deficit presented by girls was greater than that observed in boys of the same age. The difference between weekday and weekend waking times was also significantly greater in girls than in boys aged 13-18 years. Sleep deficit was significantly positively correlated with age and differences in wake up times, and significantly negatively correlated with MEQ scores, social jetlag, difference between weekday and weekend bedtimes, midpoint of sleep on weekends, and midpoint of sleep on weekends corrected for sleep deficit. A step-by-step multivariate logistic regression identified social jetlag, the difference between waking times on weekdays and weekends, and the midpoint of sleep on weekends as significant predictors of sleep deficit (Adjusted R(2) = 0.95; F = 1606.87; p school time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Effects of a 2-year behavioral weight loss intervention on sleep and mood in obese individuals treated in primary care practice.

    Science.gov (United States)

    Alfaris, Nasreen; Wadden, Thomas A; Sarwer, David B; Diwald, Lisa; Volger, Sheri; Hong, Patricia; Baxely, Amber; Minnick, Alyssa M; Vetter, Marion L; Berkowitz, Robert I; Chittams, Jesse

    2015-03-01

    To examine the effect of weight loss on sleep duration, sleep quality, and mood in 390 obese men and women who received one of three behavioral weight loss interventions in the Practice-based Opportunities for Weight Reduction trial at the University of Pennsylvania (POWER-UP). Sleep duration and quality were assessed at baseline and months 6 and 24 by the Pittsburgh Sleep Quality Index (PSQI) questionnaire and mood by the Patient Health Questionnaire-8 (PHQ-8). Changes in sleep and mood were examined according to treatment group and based on participants' having lost ≥5% of initial weight vs. sleep or mood. At month 6, however, mean (±SD) min of sleep increased significantly more in participants who lost ≥5% vs. Losing ≥5% of initial weight was associated with short-term improvements in sleep duration and sleep quality, as well as favorable short- and long-term changes in mood. © 2015 The Obesity Society.

  8. Effects of a Two-Year Behavioral Weight Loss Intervention on Sleep and Mood in Obese Individuals Treated in Primary Care Practice

    Science.gov (United States)

    Alfaris, Nasreen; Wadden, Thomas A.; Sarwer, David B; Diwald, Lisa; Volger, Sheri; Hong, Patricia; Baxely, Amber; Minnick, Alyssa M.; Vetter, Marion L.; Berkowitz, Robert I.; Chittams, Jesse

    2014-01-01

    Objective To examine the effect of weight loss on sleep duration, sleep quality, and mood in 390 obese men and women who received one of three behavioral weight loss intervention in the Practice-based Opportunities for Weight Reduction trial at the University of Pennsylvania (POWER-UP). Methods Sleep duration and quality were assessed at baseline and months 6 and 24 by the Pittsburgh Sleep Quality Index (PSQI) questionnaire and mood by the Patient Health Questionnaire-8 (PHQ-8). Changes in sleep and mood were examined according to treatment group and based on participants’ having lost ≥5% of initial weight vs sleep or mood. At month 6, however, mean (±SD) min of sleep increased significantly more in participants who lost ≥5% vs Losing ≥ 5% of initial weight was associated with short-term improvements in sleep duration and sleep quality, as well as favorable short- and long-term changes in mood. PMID:25611944

  9. Risk of Performance Decrements and Adverse Health Outcomes Resulting from Sleep Loss, Circadian Desynchronization, and Work Overload

    Science.gov (United States)

    Flynn-Evans, Erin; Gregory, Kevin; Arsintescu, Lucia; Whitmire, Alexandra

    2016-01-01

    Sleep loss, circadian desynchronization, and work overload occur to some extent for ground and flight crews, prior to and during spaceflight missions. Ground evidence indicates that such risk factors may lead to performance decrements and adverse health outcomes, which could potentially compromise mission objectives. Efforts are needed to identify the environmental and mission conditions that interfere with sleep and circadian alignment, as well as individual differences in vulnerability and resiliency to sleep loss and circadian desynchronization. Specifically, this report highlights a collection of new evidence to better characterize the risk and reveals new gaps in this risk as follows: Sleep loss is apparent during spaceflight. Astronauts consistently average less sleep during spaceflight relative to on the ground. The causes of this sleep loss remain unknown, however ground-based evidence suggests that the sleep duration of astronauts is likely to lead to performance impairment and short and long-term health consequences. Further research is needed in this area in order to develop screening tools to assess individual astronaut sleep need in order to quantify the magnitude of sleep loss during spaceflight; current and planned efforts in BHP's research portfolio address this need. In addition, it is still unclear whether the conditions of spaceflight environment lead to sleep loss or whether other factors, such as work overload lead to the reduced sleep duration. Future data mining efforts and continued data collection on the ISS will help to further characterize factors contributing to sleep loss. Sleep inertia has not been evaluated during spaceflight. Ground-based studies confirm that it takes two to four hours to achieve optimal performance after waking from a sleep episode. Sleep inertia has been associated with increased accidents and reduced performance in operational environments. Sleep inertia poses considerable risk during spaceflight when emergency

  10. Equilibration Influence on Jet Energy Loss

    International Nuclear Information System (INIS)

    Cheng Luan; Wang Enke

    2010-01-01

    With the initial conditions in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC, we investigate the consequence for parton evolution. With considering the parton equilibration, we obtain the time dependence of the opacity when the jet propagates through the QGP medium. The parton equilibration affect the jet energy loss with detailed balance evidently. Both parton energy loss from stimulated emission in the chemical non-equilibrated expanding medium and in Bjorken expanding medium are linear dependent on the propagating distance rather than square dependent in the static medium. This will increase the energy and propagating distance dependence of the parton energy loss.

  11. Teammates and social influence affect weight loss outcomes in a team-based weight loss competition.

    Science.gov (United States)

    Leahey, Tricia M; Kumar, Rajiv; Weinberg, Brad M; Wing, Rena R

    2012-07-01

    Team-based internet interventions are increasing in popularity as a way of promoting weight loss in large numbers of individuals. Given that social networks influence health behavior change, this study investigated the effects of teammates and social influence on individual weight loss during a team-based weight loss competition. Shape Up Rhode Island (SURI) 2009 was a 12-week online program open to adult residents of Rhode Island. Participants joined with a team and competed with other teams on weight loss and/or physical activity. Overweight/obese (OW/OB) individuals (N = 3,330; 76% female; age = 46.1 ± 10.8; BMI = 31.2 ± 5.3 kg/m(2)), representing 987 teams, completed the weight loss program. Multilevel modeling was used to examine whether weight loss clustered among teammates and whether percentage of teammates in the weight loss division and reported teammate influence on weight loss were associated with individual weight outcomes. OW/OB completers reported losing 4.2 ± 3.4% of initial body weight. Weight loss was similar among teammates (intraclass correlation coefficient (ICC) = 0.10, P social influence for weight loss were associated with greater percent weight loss (P's ≤ 0.002). Similarly, achieving a clinically significant (5%) weight loss tended to cluster within teams (ICC = 0.09; P social influence for weight loss were associated with increased likelihood of achieving a 5% weight loss (odds ratio (OR) = 1.06; OR = 1.20, respectively). These results suggest that teammates affect weight loss outcomes during a team-based intervention. Harnessing and maximizing teammate influence for weight loss may enhance weight outcomes in large-scale team-based programs.

  12. Sleep's influence on a reflexive form of memory that does not require voluntary attention.

    Science.gov (United States)

    Sheth, Bhavin R; Serranzana, Andrew; Anjum, Syed F; Khan, Murtuza

    2012-05-01

    Studies to date have examined the influence of sleep on forms of memory that require voluntary attention. The authors examine the influence of sleep on a form of memory that is acquired by passive viewing. Induction of the McCollough effect, and measurement of perceptual color bias before and after induction, and before and after intervening sleep, wake, or visual deprivation. Sound-attenuated sleep research room. 13 healthy volunteers (mean age = 23 years; age range = 18-31 years) with normal or corrected-to-normal vision. N/A. ) ENCODING: sleep preceded adaptation. On separate nights, each participant slept for an average of 0 (wake), 1, 2, 4, or 7 hr (complete sleep). Upon awakening, the participant's baseline perceptual color bias was measured. Then, he or she viewed an adapter consisting of alternating red/horizontal and green/vertical gratings for 5 min. Color bias was remeasured. The strength of the aftereffect is the postadaptation color bias relative to baseline. A strong orientation contingent color aftereffect was observed in all participants, but total sleep duration (TSD) prior to the adaptation did not modulate aftereffect strength. Further, prior sleep provided no benefit over prior wake. Retention: sleep followed adaptation. The procedure was similar except that adaptation preceded sleep. Postadaptation sleep, irrespective of its duration (1, 3, 5, or 7 hr), arrested aftereffect decay. By contrast, aftereffect decay was arrested during subsequent wake only if the adapted eye was visually deprived. Sleep as well as passive sensory deprivation enables the retention of a color aftereffect. Sleep shelters this reflexive form of memory in a manner akin to preventing sensory interference.

  13. Sleep structure in blindness is influenced by circadian desynchrony

    DEFF Research Database (Denmark)

    Aubin, Sébrina; Jennum, Poul; Nielsen, Tore

    2018-01-01

    We examined the structure, duration and quality of sleep, including non-rapid eye movement sleep and rapid eye movement sleep, in 11 blind individuals without conscious light perception and 11 age- and sex-matched sighted controls. Because blindness is associated with a greater incidence of free......-running circadian rhythms, we controlled for circadian phase by a measure of melatonin onset timing. When circadian rhythm was entrained and melatonin onset occurred at normal times, sleep structure did not differ between blind and sighted individuals. On the other hand, an abnormal timing of the circadian phase......, including delayed, shifted and unclassifiable melatonin onsets, led to larger rapid eye movement sleep latencies and increased wake times. No differences were observed for stages of non-rapid eye movement sleep, either between congenital and late blind and sighted individuals, or across the different...

  14. The influence of sex and gonadal hormones on sleep disorders

    Directory of Open Access Journals (Sweden)

    Orff HJ

    2014-06-01

    Full Text Available Henry J Orff, Charles J Meliska, L Fernando Martinez, Barbara L Parry Department of Psychiatry, University of California, San Diego, CA, USA Abstract: Sleep disorders such as insomnia, sleep-related breathing disorders, circadian rhythm disorders, and sleep-related movement disorders are a significant public health issue, affecting approximately 40 million people in the US each year. Sleep disturbances are observed in both men and women, though prevalence rates often differ between the sexes. In general, research suggests that women more frequently report subjective complaints of insomnia, yet show better sleep than men when evaluated on objective measures of sleep. Men are more likely to be diagnosed with obstructive sleep apnea than women, though rates of obstructive sleep apnea increase after menopause and may be generally underdiagnosed in women. Although circadian rhythm disorders are equally prevalent in men and women, studies find that women typically have earlier bedtimes and exhibit altered temperature and melatonin rhythms relative to men. Lastly, movement disorders appear to be more prevalent in women than men, presumably due to higher rates of anemia and increased risks associated with pregnancy in women. Although gonadal hormones would be expected to play a significant role in the development and/or exacerbation of sleep disturbances, no causal link between these factors has been clearly established. In large part, the impact of hormones on sleep disturbances is significantly confounded by factors such as psychiatric, physical, and lifestyle concerns, which may play an equal or greater role in the development and/or exacerbation of sleep disturbances than do hormonal factors. Current standard of care for persons with sleep disorders includes use of psychological, pharmacologic, and/or medical device supported interventions. Hormonal-based treatments are not typically recommended given the potential for long-term adverse health

  15. Topical review: sleep bruxism and the role of peripheral sensory influences.

    Science.gov (United States)

    Kato, Takafumi; Thie, Norman M; Huynh, Nelly; Miyawaki, Shouichi; Lavigne, Gilles J

    2003-01-01

    Sleep bruxism (SB) is an unusual orofacial movement described as a parafunction in dentistry and as a parasomnia in sleep medicine. Since several peripheral influences could be involved in sleep-wake regulation and the genesis of rhythmic jaw movements, the authors have reviewed the relevant literature to facilitate understanding of mechanisms possibly involved in SB genesis. Various animal and human studies indicate that during either wakefulness or anesthesia, orofacial sensory inputs (e.g., from periodontium, mucosa, and muscle) could influence jaw muscle activity. However, the role of these sensory inputs in jaw motor activity during sleep is unclear. Interestingly, during sleep, the jaw is usually open due to motor suppression; tooth contact most likely occurs in association with sleep arousal. Recent physiologic evidence supports an association between sleep arousal and SB; a sequential change from autonomic (cardiac) and brain cortical activities precede SB-related jaw motor activity. This suggests that the central and/or autonomic nervous systems, rather than peripheral sensory factors, have a dominant role in SB genesis. However, some peripheral sensory factors may exert an influence on SB through their interaction with sleep-wake mechanisms. The intent of this review is to integrate various physiologic concepts in order to better understand the mechanisms underlying the genesis of SB.

  16. Influence on working hours among shift workers and effects on sleep quality - An intervention study

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Nabe-Nielsen, Kirsten; Aust, Birgit

    2011-01-01

    in the high intensity group (p effects of interventions on sleep quality were observed. Thus, sleep quality was not improved by increasing work time influence in the present group of Danish elder care workers. This was partly due to program failure (failed intervention), but may also be due......The aim of the present intervention study was to examine if increased influence on working hours among shift workers led to better sleep quality. 391 employees were categorized into groups based on the performed activities: High (self-rostering), moderate (education and/or policy for working hours...

  17. Work schedule influence on sleep habits in elementary and high school teachers according to chronotype

    Directory of Open Access Journals (Sweden)

    Jane Carla de Souza

    2014-09-01

    Full Text Available The influence of work schedule on sleep habits and quality, and daytime sleepiness according to individual preferences in sleep schedules was assessed in 131 elementary and high school teachers through questionnaires. Teachers who initiate classes around 7:00 hr wake up earlier and show more frequency of poor sleep quality than those who start classes in the afternoon. Between them, those who have a preference for intermediate or later hours for sleep are more irregular in their wake up schedules and increase their sleep duration on the weekend compared to those with earlier sleep preferences. On the other hand, working only in the afternoon seems to provide better sleep/awake conditions for teachers, because they keep the same sleep duration during the week and on the weekend, and they are diagnosed with less daytime sleepiness. Therefore, the discussion of school start times, originally proposed for adolescents, needs to be magnified to teachers, contributing to improvement of sleep habits and life quality in school environments.

  18. Biomechanics-based active control of bedding support properties and its influence on sleep.

    Science.gov (United States)

    Van Deun, D; Verhaert, V; Willemen, T; Wuyts, J; Verbraecken, J; Exadaktylos, V; Haex, B; Vander Sloten, J

    2012-01-01

    Proper body support plays an import role in the recuperation of our body during sleep. Therefore, this study uses an automatically adapting bedding system that optimises spinal alignment throughout the night by altering the stiffness of eight comfort zones. The aim is to investigate the influence of such a dynamic sleep environment on objective and subjective sleep parameters. The bedding system contains 165 sensors that measure mattress indentation. It also includes eight actuators that control the comfort zones. Based on the measured mattress indentation, body movements and posture changes are detected. Control of spinal alignment is established by fitting personalized human models in the measured indentation. A total of 11 normal sleepers participated in this study. Sleep experiments were performed in a sleep laboratory where subjects slept three nights: a first night for adaptation, a reference night and an active support night (in counterbalanced order). Polysomnographic measurements were recorded during the nights, combined with questionnaires aiming at assessing subjective information. Subjective information on sleep quality, daytime quality and perceived number of awakenings shows significant improvements during the active support (ACS) night. Objective results showed a trend towards increased slow wave sleep. On the other hand, it was noticed that % N1-sleep was significantly increased during ACS night, while % N2-sleep was significantly decreased. No prolonged N1 periods were found during or immediately after steering.

  19. Loss of consciousness is related to hyper-correlated gamma-band activity in anesthetized macaques and sleeping humans.

    Science.gov (United States)

    Bola, Michał; Barrett, Adam B; Pigorini, Andrea; Nobili, Lino; Seth, Anil K; Marchewka, Artur

    2018-02-15

    Loss of consciousness can result from a wide range of causes, including natural sleep and pharmacologically induced anesthesia. Important insights might thus come from identifying neuronal mechanisms of loss and re-emergence of consciousness independent of a specific manipulation. Therefore, to seek neuronal signatures of loss of consciousness common to sleep and anesthesia we analyzed spontaneous electrophysiological activity recorded in two experiments. First, electrocorticography (ECoG) acquired from 4 macaque monkeys anesthetized with different anesthetic agents (ketamine, medetomidine, propofol) and, second, stereo-electroencephalography (sEEG) from 10 epilepsy patients in different wake-sleep stages (wakefulness, NREM, REM). Specifically, we investigated co-activation patterns among brain areas, defined as correlations between local amplitudes of gamma-band activity. We found that resting wakefulness was associated with intermediate levels of gamma-band coupling, indicating neither complete dependence, nor full independence among brain regions. In contrast, loss of consciousness during NREM sleep and propofol anesthesia was associated with excessively correlated brain activity, as indicated by a robust increase of number and strength of positive correlations. However, such excessively correlated brain signals were not observed during REM sleep, and were present only to a limited extent during ketamine anesthesia. This might be related to the fact that, despite suppression of behavioral responsiveness, REM sleep and ketamine anesthesia often involve presence of dream-like conscious experiences. We conclude that hyper-correlated gamma-band activity might be a signature of loss of consciousness common across various manipulations and independent of behavioral responsiveness. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Influence of burnout and sleep difficulties on the quality of life among medical students.

    Science.gov (United States)

    Pagnin, Daniel; de Queiroz, Valéria

    2015-01-01

    This study assessed the influence of burnout dimensions and sleep difficulties on the quality of life among preclinical-phase medical school students. Data were collected from 193 students through their completion of the World Health Organization Quality of Life Instrument, the Maslach Burnout Inventory-Student Survey, the Mini-Sleep Questionnaire, the Social Readjustment Rating Scale, and the Beck Depression Inventory. This survey performed hierarchical multiple regressions to quantify the effects of emotional exhaustion, cynicism, academic efficacy, and sleep difficulties on the physical, psychological, social, and environmental components of an individual's quality of life. The influence of confounding variables, such as gender, stress load, and depressive symptoms, were controlled in the statistical analyses. Physical health decreased when emotional exhaustion and sleep difficulties increased. Psychological well-being also decreased when cynicism and sleep difficulties increased. Burnout and sleep difficulties together explained 22 and 21 % of the variance in the physical and psychological well-being, respectively. On the other hand, physical health, psychological well-being, and social relationships increased when the sense of academic efficacy increased. Physical and psychological well-being are negatively associated with emotional exhaustion, cynicism, and sleep difficulties in students in the early phase of medical school. To improve the quality of life of these students, a significant effort should be directed towards burnout and sleep difficulties.

  1. Sleep and memory. I: The influence of different sleep stages on memory.

    Science.gov (United States)

    Rotenberg, V S

    1992-01-01

    A new approach to the sleep stages role in memory is discussed in the context of the two opposite patterns of behavior-search activity and renunciation of search. Search activity is activity designed to change the situation (or the subjects attitudes to it) in the absence of a definite forecast of the results of such activity, but with the constant consideration of these results at all stages of activity. Search activity increases general adaptability and body resistance while renunciation of search decreases adaptability and requires REM sleep for its compensation. Unprepared learning, which is often accompanied by failures on the first steps of learning, is suggested to produce renunciation of search, which decreases learning ability, suppress retention, and increase REM sleep requirement. A prolonged REM sleep deprivation before training causes learned helplessness and disturbs the learning process, while short REM sleep deprivation cause the "rebound" of the compensatory search activity that interferes with passive avoidance. REM sleep deprivation performed after a training session can increase distress caused by a training procedure, with the subsequent negative outcome on retention.

  2. The influence of PTSD, sleep fears, and neighborhood stress on insomnia and short sleep duration in urban, young adult, African Americans.

    Science.gov (United States)

    Hall Brown, Tyish; Mellman, Thomas A

    2014-01-01

    African Americans residing in stressful urban environments have high rates of insomnia and short sleep duration, both of which are associated with adverse health outcomes. However, limited data exist that explore factors influencing inadequate sleep in this high-risk population. This study sought to evaluate the contributions of demographics, trauma, posttraumatic stress disorder (PTSD) symptoms, sleep fears, and neighborhood stress to both insomnia and short sleep in urban African American young adults. Data were analyzed from self-report measures completed by 378 participants 18-35 years of age. PTSD symptom severity and sleep fears were independently associated with insomnia severity, and sleep fears was associated with sleep duration. Results have implications for preventative health intervention strategies for urban African American young adults.

  3. Ramadan fasting influences on food intake consumption, sleep ...

    African Journals Online (AJOL)

    AJL

    2013-05-22

    May 22, 2013 ... Key words: Ramadan fasting, food intake consumption, sleep schedule, body weight, plasma parameters, ... month of intermittent fasting (Nomani et al. ..... ponses to exercise, fluid, and energy balances during Ramadan in.

  4. Medical and genetic differences in the adverse impact of sleep loss on performance: ethical considerations for the medical profession.

    Science.gov (United States)

    Czeisler, Charles A

    2009-01-01

    The Institute of Medicine recently concluded that-on average-medical residents make more serious medical errors and have more motor vehicle crashes when they are deprived of sleep. In the interest of public safety, society has required limitations on work hours in many other safety sensitive occupations, including transportation and nuclear power generation. Those who argue in favor of traditional extended duration resident work hours often suggest that there are inter- individual differences in response to acute sleep loss or chronic sleep deprivation, implying that physicians may be more resistant than the average person to the detrimental effects of sleep deprivation on performance, although there is no evidence that physicians are particularly resistant to such effects. Indeed, recent investigations have identified genetic polymorphisms that may convey a relative resistance to the effects of prolonged wakefulness on a subset of the healthy population, although there is no evidence that physicians are over-represented in this cohort. Conversely, there are also genetic polymorphisms, sleep disorders and other inter-individual differences that appear to convey an increased vulnerability to the performance-impairing effects of 24 hours of wakefulness. Given the magnitude of inter-individual differences in the effect of sleep loss on cognitive performance, and the sizeable proportion of the population affected by sleep disorders, hospitals face a number of ethical dilemmas. How should the work hours of physicians be limited to protect patient safety optimally? For example, some have argued that, in contrast to other professions, work schedules that repeatedly induce acute and chronic sleep loss are uniquely essential to the training of physicians. If evidence were to prove this premise to be correct, how should such training be ethically accomplished in the quartile of physicians and surgeons who are most vulnerable to the effects of sleep loss on performance

  5. Unrecognized Sleep Loss Accumulated in Daily Life Can Promote Brain Hyperreactivity to Food Cue.

    Science.gov (United States)

    Katsunuma, Ruri; Oba, Kentaro; Kitamura, Shingo; Motomura, Yuki; Terasawa, Yuri; Nakazaki, Kyoko; Hida, Akiko; Moriguchi, Yoshiya; Mishima, Kazuo

    2017-10-01

    Epidemiological studies have shown that sleep debt increases the risk of obesity. Experimental total sleep deprivation (TSD) has been reported to activate the reward system in response to food stimuli, but food-related responses in everyday sleep habits, which could lead to obesity, have not been addressed. Here, we report that habitual sleep time at home among volunteers without any sleep concerns was shorter than their optimal sleep time estimated by the 9-day extended sleep intervention, which indicates that participants had already been in sleep debt in their usual sleep habits. The amygdala and anterior insula, which are responsible for both affective responses and reward prediction, were found to exhibit significantly lowered activity in the optimal sleep condition. Additionally, a subsequent one-night period of TSD reactivated the right anterior insula in response to food images; however, the activity level of amygdala remained lowered. These findings indicate that (1) our brain is at risk of hyperactivation to food triggers in everyday life, which could be a risk factor for obesity and lifestyle diseases, and (2) optimal sleep appears to reduce this hypersensitivity to food stimuli. © 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.

  6. The sleeping patterns of Head Start children and the influence on developmental outcomes.

    Science.gov (United States)

    Schlieber, M; Han, J

    2018-05-01

    Sleep has a significant influence on children's development. The objective of this study was to investigate Head Start children's sleeping patterns and the impact on cognitive and behavioural outcomes. Using the 2009 cohort of the Head Start Family and Child Experiences Survey (N = 2,868), information on sleeping patterns was assessed through parent interviews. Cognitive outcomes were assessed using direct assessments (Peabody Picture Vocabulary Test-IV, the Expressive One-Word Picture Vocabulary Test, and Subtests of the Woodcock-Johnson III) in addition to teacher report. Behavioural outcomes were assessed through parent and teacher reports. A multiple regression analysis was performed for each outcome variable. Descriptive findings showed that 89% of children had a regular bedtime at least 4 days per week and that the average amount of sleep per night was 10.41 hr. White mothers were more likely than other racial groups to adhere to a consistent bedtime, and maternal employment predicted less hour of sleep per night. Multiple regression analyses revealed that disrupted sleep had a negative influence on cognitive outcomes, especially in areas of mathematical problem solving, receptive language, teacher-reported literacy behaviours, and approaches to learning. Disrupted sleep was associated with the risk of misbehaviour by increasing teacher and parent ratings on aggressive behaviours, hyperactivity, and withdrawing in addition to decreased scores on overall social skills. Having an inconsistent bedtime negatively predicted expressive vocabulary and teacher-reported literacy behaviours. The findings of this study support the influential role of sleep on children's development. Sleeping through the night and having a consistent bedtime were found to be predictive of many areas of cognitive and behavioural development. Head Start staff can provide the supports to increase parental knowledge on appropriate child sleep practices. © 2017 John Wiley & Sons Ltd.

  7. Electroencephalogram approximate entropy influenced by both age and sleep

    Directory of Open Access Journals (Sweden)

    Gerick M. H. Lee

    2013-12-01

    Full Text Available The use of information-based measures to assess changes in conscious state is an increasingly popular topic. Though recent results have seemed to justify the merits of such methods, little has been done to investigate the applicability of such measures to children. For our work, we used the approximate entropy (ApEn, a measure previously shown to correlate with changes in conscious state when applied to the electroencephalogram (EEG, and sought to confirm whether previously reported trends in adult ApEn values across wake and sleep were present in children. Besides validating the prior findings that ApEn decreases from wake to sleep (including wake, rapid eye movement [REM] sleep, and non-REM sleep in adults, we found that previously reported ApEn decreases across vigilance states in adults were also present in children (ApEn trends for both age groups: wake > REM sleep > non-REM sleep. When comparing ApEn values between age groups, adults had significantly larger ApEn values than children during wakefulness. After the application of an 8 Hz high-pass filter to the EEG signal, ApEn values were recalculated. The number of electrodes with significant vigilance state effects dropped from all 109 electrodes with the original 1 Hz filter to 1 electrode with the 8 Hz filter. The number of electrodes with significant age effects dropped from ten to four. Our results support the notion that ApEn can reliably distinguish between vigilance states, with low-frequency sleep-related oscillations implicated as the driver of changes between vigilance states. We suggest that the observed differences between adult and child ApEn values during wake may reflect differences in connectivity between age groups, a factor which may be important in the use of EEG to measure consciousness.

  8. Sleep, Rhythms, and the Endocrine Brain: Influence of Sex and Gonadal Hormones

    Science.gov (United States)

    Mong, Jessica A.; Baker, Fiona C.; Mahoney, Megan M.; Paul, Ketema N.; Schwartz, Michael D.; Semba, Kazue; Silver, Rae

    2011-01-01

    While much is known about the mechanisms that underlie sleep and circadian rhythms, the investigation into sex differences and gonadal steroid modulation of sleep and biological rhythms is in its infancy. There is a growing recognition of sex disparities in sleep and rhythm disorders. Understanding how neuroendocrine mediators and sex differences influence sleep and biological rhythms is central to advancing our understanding of sleep-related disorders. While it is known that ovarian steroids affect circadian rhythms in rodents, the role of androgen is less understood. Surprising findings that androgens, acting via androgen receptors in the master “circadian clock” within the suprachiasmatic nucleus (SCN), modulate photic effects on activity in males points to novel mechanisms of circadian control. Work in aromatase deficient (ArKO) mice suggests that some sex differences in photic responsiveness are independent of gonadal hormone effects during development. In parallel, aspects of sex differences in sleep are also reported to be independent of gonadal steroids and may involve sex chromosome complement. This a summary of recent work illustrating how sex differences and gonadal hormones influence sleep and circadian rhythms that was presented at a mini-symposium at the 2011 annual meeting of the Society for Neuroscience. PMID:22072663

  9. Influence of magnetostriction on hysteresis loss of electrical steel sheet

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Hirotoshi, E-mail: tada.547.hirotoshi@jp.nssmc.com [Steel Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, 1-8 Fuso-cho, Amagasaki, Hyogo 660-0891 (Japan); Fujimura, Hiroshi; Yashiki, Hiroyoshi [Steel Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, 1-8 Fuso-cho, Amagasaki, Hyogo 660-0891 (Japan)

    2013-01-15

    To reveal influence of magnetostriction on hysteresis loss of electrical steel sheet, hysteresis loss and magnetostriction of non-oriented electrical steel sheets (NOs) with various Si and Al content and grain size and grain oriented electrical steel sheet (GO) were measured under compressive or tensile stress. Here, Si and Al content and stress were focused on as the way to change magnetostriction. Stress direction and magnetizing direction were parallel to the rolling direction. Following three main results were obtained. The first is hysteresis loss of NO with same grain size which increased with magnetostriction independently of Si and Al content and stress. The second is hysteresis loss of NO was larger than that of GO under same magnetostriction. The third is hysteresis loss of NO at magnetostriction of zero was inversely proportional to grain size. Even if the grain size of NO increased to be similar size of GO without changing texture, the hysteresis loss of NO at magnetostriction of zero would be larger than that of GO because of the difference in texture. - Highlights: Black-Right-Pointing-Pointer Hysteresis loss and magnetostriction of NO and GO were measured under stress. Black-Right-Pointing-Pointer Hysteresis loss of NO was proportional to magnetostriction. Black-Right-Pointing-Pointer Hysteresis loss of GO was proportional to magnetostriction. Black-Right-Pointing-Pointer Hysteresis loss of NO was larger than that of GO under samemagnetostriction. Black-Right-Pointing-Pointer Hysteresis loss was separated into 4 components.

  10. Influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students

    OpenAIRE

    Benavente, Sonia Betzabeth Ticona; Silva, Rodrigo Marques da; Higashi, Aline Baraldi; Guido, Laura de Azevedo; Costa, Ana Lucia Siqueira

    2014-01-01

    Objective:To analyze the influence of stress factors and socio-demographic characteristics on the sleep quality of nursing students. Method: An analytical cross-sectional and quantitative study, conducted with 151 nursing students in São Paulo between March and April of 2012. A form for socio-demographic characteristics, the Instrument to Evaluate Stress in Nursing Students and the Pittsburgh Sleep Index were applied. Results: High levels of stress was predominant for Time Management (27.8%) ...

  11. Influence of burnout and sleep difficulties on the quality of life among medical students

    OpenAIRE

    Pagnin, Daniel; de Queiroz, Val?ria

    2015-01-01

    This study assessed the influence of burnout dimensions and sleep difficulties on the quality of life among preclinical-phase medical school students. Data were collected from 193 students through their completion of the World Health Organization Quality of Life Instrument, the Maslach Burnout Inventory?Student Survey, the Mini-Sleep Questionnaire, the Social Readjustment Rating Scale, and the Beck Depression Inventory. This survey performed hierarchical multiple regressions to quantify the e...

  12. Sleep-wake patterns and their influence on school performance in Portuguese adolescents

    OpenAIRE

    Duarte, João; Nelas, Paula; Chaves, Cláudia; Ferreira, Manuela; Coutinho, Emília; Cunha, Madalena

    2014-01-01

    Objective: To characterise sleep-wake patterns and their influence on academic performance for a sample of Portuguese adolescents. Research design: Cross-sectional, analytical-explanatory, correlational epidemiological research. The protocol includes the composite morningness questionnaire (Barton et al, 1985 adapted by Silva et al, 1985), the Epworth Sleepiness Scale (Murray, 1991), chronic fatigue scale (Smith et al, 1995), the Pittsburgh Sleep Quality Index (Buysse, 1988), Educational A...

  13. Night sleep influences white matter microstructure in bipolar depression.

    Science.gov (United States)

    Benedetti, Francesco; Melloni, Elisa M T; Dallaspezia, Sara; Bollettini, Irene; Locatelli, Clara; Poletti, Sara; Colombo, Cristina

    2017-08-15

    Alteration of circadian rhythms and sleep disruption are prominent trait-like features of bipolar disorder (BD). Diffusion tensor imaging (DTI) measures suggest a widespread alteration of white matter (WM) microstructure in patients with BD. Sleep promotes myelination and oligodendrocyte precursor cells proliferation. We hypothesized a possible association between DTI measures of WM microstructure and sleep quantity measures in BD. We studied 69 inpatients affected by a depressive episode in course of type I BD. We used whole brain tract-based spatial statistics on DTI measures of WM microstructure: axial, radial, and mean diffusivity (AD, RD, MD), and fractional anisotropy (FA). Self-assessed measures of time asleep (TA) and total sleep time (TST) were extracted from the Pittsburgh Sleep Quality Index (PSQI). Actigraphic recordings were performed on a subsample of 23 patients. We observed a positive correlation of DTI measures of FA with actigraphic measures of TA and TST, and with PSQI measure of TA. DTI measures of RD inversely associated with actigraphic measure of TA, and with PSQI measures of TA and TST. Several WM tracts were involved, including corpus callosum, cyngulate gyrus, uncinate fasciculus, left superior and inferior longitudinal and fronto-occipital fasciculi, thalamic radiation, corona radiata, retrolenticular part of internal capsule and corticospinal tract. The study is correlational in nature, and no conclusion about a causal connection can be drawn. Reduced FA with increased RD and MD indicate higher water diffusivity associated with less organized myelin and/or axonal structures. Our findings suggest an association between sleep disruption and these measures of brain microstructure in specific tracts contributing to the functional connectivity in BD. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The Influence of CO2 on Genioglossus Muscle After-Discharge Following Arousal From Sleep.

    Science.gov (United States)

    Cori, Jennifer M; Rochford, Peter D; O'Donoghue, Fergal J; Trinder, John; Jordan, Amy S

    2017-11-01

    Ventilatory after-discharge (sustained elevation of ventilation following stimulus removal) occurs during sleep but not when hypocapnia is present. Genioglossus after-discharge also occurs during sleep, but CO2 effects have not been assessed. The relevance is that postarousal after-discharge may protect against upper airway collapse. This study aimed to determine whether arousal elicits genioglossus after-discharge that persists into sleep, and whether it is influenced by CO2. Twenty-four healthy individuals (6 female) slept with a nasal mask and ventilator. Sleep (EEG, EOG, EMG), ventilation (pneumotachograph), end-tidal CO2 (PETCO2), and intramuscular genioglossus EMG were monitored. NREM eucapnia was determined during 5 minutes on continuous positive airway pressure (4 cmH2O). Inspiratory pressure support was increased until PETCO2 was ≥2 mm Hg below NREM eucapnia. Supplemental CO2 was added to reproduce normocapnia, without changing ventilator settings. Arousals were induced by auditory tones and genioglossus EMG compared during steady-state hypocapnia and normocapnia. Eleven participants (4 female) provided data. Prearousal PETCO2 was less (p sleep. For tonic activity, after-discharge lasted four breaths irrespective of CO2 condition. For peak activity, after-discharge lasted one breath during hypocapnia and 6 breaths during normocapnia. However, when peak activity following the return to sleep was compared between CO2 conditions no individual breath differences were observed. Postarousal genioglossal after-discharge may protect against upper airway collapse during sleep. Steady-state CO2 levels minimally influence postarousal genioglossus after-discharge. © 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.

  15. Ramadan fasting influences on food intake consumption, sleep ...

    African Journals Online (AJOL)

    This study examines the changes in the lifestyle that accompanied Ramadan fasting. For this purpose, we followed the questionnaire programming meals, food consumption and sleep rhythm. We also followed changes in plasma biological parameters. The results show that daily energy consumption was not changed and ...

  16. The influence of orthognathic surgery on ventilation during sleep

    Czech Academy of Sciences Publication Activity Database

    Foltán, R.; Hoffmannová, J.; Pavlíková, G.; Hanzelka, T.; Klíma, K.; Horká, E.; Adámek, S.; Šedý, Jiří

    2011-01-01

    Roč. 40, č. 2 (2011), s. 146-149 ISSN 0901-5027 Institutional research plan: CEZ:AV0Z50390512 Keywords : orthognathic surgery * obstructive sleep apnea * ventilation Subject RIV: FH - Neurology Impact factor: 1.506, year: 2011

  17. The Influence of Sleep on the Consolidation of Positive Emotional Memories: Preliminary Evidence

    Directory of Open Access Journals (Sweden)

    Alexis M. Chambers

    2014-05-01

    Full Text Available Studies have not only shown that a period of sleep following learning offers greater benefits to later memory than a period of wakefulness, but also that sleep actively promotes those components of memories that are emotionally salient. However, sleep's role in emotional memory consolidation has largely been investigated with memories that are specifically negative in content, such as memory for negative images or texts, leaving open the question of whether sleep influences positive memories in a similar manner. The current study investigated the emotional memory trade-off effect for positive versus neutral information. Scenes in which a positive or neutral object was placed on a neutral background were encoded prior to a period of polysomnographically-monitored nocturnal sleep or daytime wakefulness. Recognition memory was tested for the objects and backgrounds separately following the delay using the Remember/Know paradigm. Compared to wake participants, those who slept during the delay had increased recollection memory performance for positive objects, but not the neutral components of the studied scenes. Further, familiarity of positive objects was negatively correlated with REM latency. These results provide preliminary evidence that sleep contributes to the selective processing of positive memories, and point toward a role for REM sleep in positive memory formation.

  18. The influence of sleep deprivation and oscillating motion on sleepiness, motion sickness, and cognitive and motor performance.

    Science.gov (United States)

    Kaplan, Janna; Ventura, Joel; Bakshi, Avijit; Pierobon, Alberto; Lackner, James R; DiZio, Paul

    2017-01-01

    Our goal was to determine how sleep deprivation, nauseogenic motion, and a combination of motion and sleep deprivation affect cognitive vigilance, visual-spatial perception, motor learning and retention, and balance. We exposed four groups of subjects to different combinations of normal 8h sleep or 4h sleep for two nights combined with testing under stationary conditions or during 0.28Hz horizontal linear oscillation. On the two days following controlled sleep, all subjects underwent four test sessions per day that included evaluations of fatigue, motion sickness, vigilance, perceptual discrimination, perceptual learning, motor performance and learning, and balance. Sleep loss and exposure to linear oscillation had additive or multiplicative relationships to sleepiness, motion sickness severity, decreases in vigilance and in perceptual discrimination and learning. Sleep loss also decelerated the rate of adaptation to motion sickness over repeated sessions. Sleep loss degraded the capacity to compensate for novel robotically induced perturbations of reaching movements but did not adversely affect adaptive recovery of accurate reaching. Overall, tasks requiring substantial attention to cognitive and motor demands were degraded more than tasks that were more automatic. Our findings indicate that predicting performance needs to take into account in addition to sleep loss, the attentional demands and novelty of tasks, the motion environment in which individuals will be performing and their prior susceptibility to motion sickness during exposure to provocative motion stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Sleep-dependent memory consolidation in patients with sleep disorders.

    Science.gov (United States)

    Cipolli, Carlo; Mazzetti, Michela; Plazzi, Giuseppe

    2013-04-01

    Sleep can improve the off-line memory consolidation of new items of declarative and non-declarative information in healthy subjects, whereas acute sleep loss, as well as sleep restriction and fragmentation, impair consolidation. This suggests that, by modifying the amount and/or architecture of sleep, chronic sleep disorders may also lead to a lower gain in off-line consolidation, which in turn may be responsible for the varying levels of impaired performance at memory tasks usually observed in sleep-disordered patients. The experimental studies conducted to date have shown specific impairments of sleep-dependent consolidation overall for verbal and visual declarative information in patients with primary insomnia, for verbal declarative information in patients with obstructive sleep apnoeas, and for visual procedural skills in patients with narcolepsy-cataplexy. These findings corroborate the hypothesis that impaired consolidation is a consequence of the chronically altered organization of sleep. Moreover, they raise several novel questions as to: a) the reversibility of consolidation impairment in the case of effective treatment, b) the possible negative influence of altered prior sleep also on the encoding of new information, and c) the relationships between altered sleep and memory impairment in patients with other (medical, psychiatric or neurological) diseases associated with quantitative and/or qualitative changes of sleep architecture. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. On the need of objective vigilance monitoring: effects of sleep loss on target detection and task-negative activity using combined EEG/fMRI

    NARCIS (Netherlands)

    Czisch, M.; Wehrle, R.; Harsay, H.A.; Wetter, T.C.; Holsboer, F.; Sämann, P.G.; Drummond, S.P.A.

    2012-01-01

    Sleep loss affects attention by reducing levels of arousal and alertness. The neural mechanisms underlying the compensatory efforts of the brain to maintain attention and performance after sleep deprivation (SD) are not fully understood. Previous neuroimaging studies of SD have not been able to

  1. Influence of cued-fear conditioning and its impairment on NREM sleep.

    Science.gov (United States)

    Kumar, Tankesh; Jha, Sushil K

    2017-10-01

    Many studies suggest that fear conditioning influences sleep. It is, however, not known if the changes in sleep architecture after fear conditioning are essentially associated with the consolidation of fearful memory or with fear itself. Here, we have observed that within sleep, NREM sleep consistently remained augmented after the consolidation of cued fear-conditioned memory. But a similar change did not occur after impairing memory consolidation by blocking new protein synthesis and glutamate transmission between glial-neuronal loop in the lateral amygdala (LA). Anisomycin (a protein synthesis inhibitor) and DL-α-amino-adipic acid (DL- α -AA) (a glial glutamine synthetase enzyme inhibitor) were microinjected into the LA soon after cued fear-conditioning to induce memory impairment. On the post-conditioning day, animals in both the groups exhibited significantly less freezing. In memory-consolidated groups (vehicle groups), NREM sleep significantly increased during 2nd to 5th hours after training compared to their baseline days. However, in memory impaired groups (anisomycin and DL- α -AA microinjected groups), similar changes were not observed. Our results thus suggest that changes in sleep architecture after cued fear-conditioning are indeed a consolidation dependent event. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Influence of sleep apnea severity on blood pressure variability of patients with hypertension.

    Science.gov (United States)

    Steinhorst, Ana P; Gonçalves, Sandro C; Oliveira, Ana T; Massierer, Daniela; Gus, Miguel; Fuchs, Sandra C; Moreira, Leila B; Martinez, Denis; Fuchs, Flávio D

    2014-05-01

    Obstructive sleep apnea (OSA) is a risk factor for the development of hypertension and cardiovascular disease. Apnea overloads the autonomic cardiovascular control system and may influence blood pressure variability, a risk for vascular damage independent of blood pressure levels. This study investigates the hypothesis that blood pressure variability is associated with OSA. In a cross-sectional study, 107 patients with hypertension underwent 24-h ambulatory blood pressure monitoring and level III polysomnography to detect sleep apnea. Pressure variability was assessed by the first derivative of blood pressure over time, the time rate index, and by the standard deviation of blood pressure measurements. The association between the apnea-hypopnea index and blood pressure variability was tested by univariate and multivariate methods. The 57 patients with apnea were older, had higher blood pressure, and had longer duration of hypertension than the 50 patients without apnea. Patients with apnea-hypopnea index (AHI) ≥ 10 had higher blood pressure variability assessed by the standard deviation than patients with AHI variability assessed by the time rate index presented a trend for association during sleep (P = 0.07). Daytime blood pressure variability was not associated with the severity of sleep apnea. Sleep apnea increases nighttime blood pressure variability in patients with hypertension and may be another pathway linking sleep abnormalities to cardiovascular disease.

  3. Sleep Quality and Factors Influencing Self-Reported Sleep Duration and Quality in the General Internal Medicine Inpatient Population.

    Directory of Open Access Journals (Sweden)

    Selina Dobing

    Full Text Available Sleep quality in hospitalized Canadian General Internal Medicine patients is not well characterized. Our goals were to characterize hospital sleep quality in this population and identify potentially modifiable barriers to good sleep.GIM inpatients at a quaternary centre in Edmonton, Canada completed a survey, including the Verran-Snyder Halpern (VSH questionnaire, to characterize the previous night's sleep within 48 hours prior to discharge. A chart review was also completed to assess comorbidities, discharge diagnoses, and pharmaceutical sleep aid use.Patients reported significantly worse nighttime sleep duration in hospital compared with home (mean 5.5 versus 7.0 hours per night, p < 0.0001. Sleep quality was poor, as measured by the VSH disturbance (mean 371, effectiveness (190, and supplementation (115 subscales. Variables independently associated with poorer sleep duration in multivariable regression include prior diagnosis of sleep disorder and multi-patient occupancy rooms. Age, sex, admitting diagnosis, length of stay, frequency of vital checks, and use of sleep pharmaceuticals during the index hospitalization were not associated with sleep duration. The most frequently reported reasons for poor sleep included noise (59%, nursing interruptions (30%, uncomfortable beds (18%, bright lights (16%, unfamiliar surroundings (14%, and pain (9%.Sleep quality for GIM inpatients is significantly worse in hospital than at home. There is a need to test non-pharmacologic interventions to address the most frequently identified factors causing poor sleep hygiene for GIM inpatients.

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

    Science.gov (United States)

    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.

  5. Can Ayahuasca and sleep loss change sexual performance in male rats?

    Science.gov (United States)

    Alvarenga, T A; Polesel, D N; Matos, G; Garcia, V A; Costa, J L; Tufik, S; Andersen, M L

    2014-10-01

    The ingestion of the beverage Ayahuasca usually occurs in religious ceremonies that are performed during the night leading to sleep deprivation. The purpose of the present study was to characterize the acute effects of Ayahuasca upon the sexual response of sleep deprived male rats. One group of sexually experienced male Wistar rats were submitted to a paradoxical sleep deprivation (PSD) protocol for 96h, while another group spent the same amount of time in the home cage (CTRL). After this period, either saline or Ayahuasca drink (250, 500 and 1000μgmL(-1)) was administered by gavage and sexual behavior and hormonal concentrations were measured. Ayahuasca alone significantly decreased sexual performance at all doses. However, in sleep deprived rats, the lower dose increased sexual performance while the intermediate dose produced a detrimental effect on sexual response compared to the CTRL rats at the same dose. Regarding the hormonal analyses, a lower testosterone concentration was observed in sleep-deprived saline rats in relation to the CTRL group. Progesterone was significantly lower only in PSD rats at the dose 500μgmL(-1) compared with CTRL-500μgmL(-1) group. Corticosterone was unchanged among the groups evaluated. Our results suggest that Ayahuasca intake markedly impaired sexual performance alone, but, when combined with sleep deprivation, had significant, but heterogeneous, effects on male sexual response. Copyright © 2014. Published by Elsevier B.V.

  6. Influence of obstructive sleep apnea on fatty liver disease: role of chronic intermittent hypoxia.

    Science.gov (United States)

    Türkay, Cansel; Ozol, Duygu; Kasapoğlu, Benan; Kirbas, Ismail; Yıldırım, Zeki; Yiğitoğlu, Ramazan

    2012-02-01

    Currently the common pathogenetic mechanisms in nonalcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) are gaining increased attention. The aim of this study is to find out the influence of chronic intermittent hypoxemia and OSA related parameters to the severity of NAFLD. We examined the liver functions tests and ultrasonographic data of liver as well as markers of OSA severity (apnea-hypopnea index [AHI], oxygen desaturation index, minimum oxygen saturation, percentage of time spent with S(pO(2)) hypoxia during sleep. The prevalence of NAFLD was higher in patients with severe OSA, suggesting a role for nocturnal hypoxemia in the pathogenesis of fatty liver disease.

  7. The influence of loss aversion on mountain bikers' behavioral intentions.

    Science.gov (United States)

    Purrington, Andrew; Zinn, Harry

    2011-09-01

    Public involvement in management decision making has received increased attention from researchers in recent years. These studies, however, have rarely considered differences in behavior resulting from gains and losses, despite ample evidence that individuals' behavior is not the same across situations. Individuals are often more sensitive to losses than gains, which research suggests is related to ownership (real or perceived) of the item lost. We present evidence from a within-subjects quasi-experimental design to test whether mountain bikers' reported intentions differ between gain based and loss based conditions. These data were analyzed using a multi-step repeated measures analysis of variance and repeated measures analysis of covariance. The results suggest that losses are more powerful than gains in motivating public engagement in management decision making. Further, the type of action was also shown to influence behavioral intentions. Additional analyses provide support to the claim that, centrality, used as a proximate measure of ownership, moderates the contextual effects on behavioral intentions. Thus, loss aversion, moderated by ownership, is a plausible explanation of stakeholder involvement.

  8. Sleep loss and circadian disruption in shift work: health burden and management.

    Science.gov (United States)

    Rajaratnam, Shantha M W; Howard, Mark E; Grunstein, Ronald R

    2013-10-21

    About 1.5 million Australians are shift workers. Shift work is associated with adverse health, safety and performance outcomes. Circadian rhythm misalignment, inadequate and poor-quality sleep, and sleep disorders such as sleep apnoea, insomnia and shift work disorder (excessive sleepiness and/or insomnia temporally associated with the work schedule) contribute to these associations. Falling asleep at work at least once a week occurs in 32%-36% of shift workers. Risk of occupational accidents is at least 60% higher for non-day shift workers. Shift workers also have higher rates of cardiometabolic diseases and mood disturbances. Road and workplace accidents related to excessive sleepiness, to which shift work is a significant contributor, are estimated to cost $71-$93 billion per annum in the United States. There is growing evidence that understanding the interindividual variability in sleep-wake responses to shift work will help detect and manage workers vulnerable to the health consequences of shift work. A range of approaches can be used to enhance alertness in shift workers, including screening and treating sleep disorders, melatonin treatment to promote sleep during the daytime, and avoidance of inappropriate use of sedatives and wakefulness-promoters such as modafinil and caffeine. Short naps, which minimise sleep inertia, are generally effective. Shifting the circadian pacemaker with appropriately timed melatonin and/or bright light may be used to facilitate adjustment to a shift work schedule in some situations, such as a long sequence of night work. It is important to manage the health risk of shift workers by minimising vascular risk factors through dietary and other lifestyle approaches.

  9. The influence of care interventions on the continuity of sleep of intensive care unit patients.

    Science.gov (United States)

    Hamze, Fernanda Luiza; de Souza, Cristiane Chaves; Chianca, Tânia Couto Machado

    2015-01-01

    to identify care interventions, performed by the health team, and their influence on the continuity of sleep of patients hospitalized in the Intensive Care Unit. descriptive study with a sample of 12 patients. A filming technique was used for the data collection. The awakenings from sleep were measured using the actigraphy method. The analysis of the data was descriptive, processed using the Statistical Package for the Social Sciences software. 529 care interventions were identified, grouped into 28 different types, of which 12 (42.8%) caused awakening from sleep for the patients. A mean of 44.1 interventions/patient/day was observed, with 1.8 interventions/patient/hour. The administration of oral medicine and food were the interventions that caused higher frequencies of awakenings in the patients. it was identified that the health care interventions can harm the sleep of ICU patients. It is recommended that health professionals rethink the planning of interventions according to the individual demand of the patients, with the diversification of schedules and introduction of new practices to improve the quality of sleep of Intensive Care Unit patients.

  10. The influence of care interventions on the continuity of sleep of intensive care unit patients

    Directory of Open Access Journals (Sweden)

    Fernanda Luiza Hamze

    2015-10-01

    Full Text Available Objective: to identify care interventions, performed by the health team, and their influence on the continuity of sleep of patients hospitalized in the Intensive Care Unit.Method: descriptive study with a sample of 12 patients. A filming technique was used for the data collection. The awakenings from sleep were measured using the actigraphy method. The analysis of the data was descriptive, processed using the Statistical Package for the Social Sciences software.Results: 529 care interventions were identified, grouped into 28 different types, of which 12 (42.8% caused awakening from sleep for the patients. A mean of 44.1 interventions/patient/day was observed, with 1.8 interventions/patient/hour. The administration of oral medicine and food were the interventions that caused higher frequencies of awakenings in the patients.Conclusion: it was identified that the health care interventions can harm the sleep of ICU patients. It is recommended that health professionals rethink the planning of interventions according to the individual demand of the patients, with the diversification of schedules and introduction of new practices to improve the quality of sleep of Intensive Care Unit patients.

  11. An experimental study on the effect of noise and sleep loss on human performance using the measure of TCI during NPP maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hyun Jun

    2008-02-15

    There are various stressors in NPP maintenance, such as environmental stressors and work-related stressors. These stressors degrade human performance and increase human error. Stress has not been largely considered as a factor of human error in root cause analyses. Recently, however, regulatory bodies and research institutes have worked to manage the physical condition of the operator and improve the environment and methods of NPP maintenance. These efforts have focused on reducing the incidence of human error due to stress. It is necessary to study how much stress affects human performance before these efforts are complete. The objectives of the present study are to formulate a Task Concentration Index (TCI) based on Electrocardiogram (ECG) signals in order to evaluate the degree to which a person concentrates on a task experimentally. With the TCI, the study will also evaluate the effects of noise and sleep loss on human performance during NPP maintenance tasks. Stress influences the efficiency of information processing and data input and output. Stress and human error are tightly linked in a closed-loop combination. The human body responds to stress by activating the nervous system and specific hormones. Therefore, physiological signals are changed by stress. A spectral analysis of Heart Rate Variability (HRV) provides a noninvasive technique for indirectly measuring sympathetic and parasympathetic modulation during specific tasks. The high-frequency component (HF, 0.15∼0.4Hz) reflects momentary respiration and is mediated by the parasympathetic nervous system. The low-frequency component (LF, 0.04∼0.15Hz) has been interpreted mainly as an indicator of sympathetic influences (especially when expressed in normalized units). When the level of stress is high, the Normalized Low Frequency component (NoLF) of HRV signals is generally higher than the normal state. The difference in NoLF readings between a normal state and during a task could be used to evaluate

  12. An experimental study on the effect of noise and sleep loss on human performance using the measure of TCI during NPP maintenance

    International Nuclear Information System (INIS)

    Jo, Hyun Jun

    2008-02-01

    There are various stressors in NPP maintenance, such as environmental stressors and work-related stressors. These stressors degrade human performance and increase human error. Stress has not been largely considered as a factor of human error in root cause analyses. Recently, however, regulatory bodies and research institutes have worked to manage the physical condition of the operator and improve the environment and methods of NPP maintenance. These efforts have focused on reducing the incidence of human error due to stress. It is necessary to study how much stress affects human performance before these efforts are complete. The objectives of the present study are to formulate a Task Concentration Index (TCI) based on Electrocardiogram (ECG) signals in order to evaluate the degree to which a person concentrates on a task experimentally. With the TCI, the study will also evaluate the effects of noise and sleep loss on human performance during NPP maintenance tasks. Stress influences the efficiency of information processing and data input and output. Stress and human error are tightly linked in a closed-loop combination. The human body responds to stress by activating the nervous system and specific hormones. Therefore, physiological signals are changed by stress. A spectral analysis of Heart Rate Variability (HRV) provides a noninvasive technique for indirectly measuring sympathetic and parasympathetic modulation during specific tasks. The high-frequency component (HF, 0.15∼0.4Hz) reflects momentary respiration and is mediated by the parasympathetic nervous system. The low-frequency component (LF, 0.04∼0.15Hz) has been interpreted mainly as an indicator of sympathetic influences (especially when expressed in normalized units). When the level of stress is high, the Normalized Low Frequency component (NoLF) of HRV signals is generally higher than the normal state. The difference in NoLF readings between a normal state and during a task could be used to evaluate

  13. Effects of Sleep Deprivation on Brain Bioenergetics, Sleep, and Cognitive Performance in Cocaine-Dependent Individuals

    Science.gov (United States)

    Trksak, George H.; Bracken, Bethany K.; Jensen, J. Eric; Plante, David T.; Penetar, David M.; Tartarini, Wendy L.; Maywalt, Melissa A.; Dorsey, Cynthia M.; Renshaw, Perry F.; Lukas, Scott E.

    2013-01-01

    In cocaine-dependent individuals, sleep is disturbed during cocaine use and abstinence, highlighting the importance of examining the behavioral and homeostatic response to acute sleep loss in these individuals. The current study was designed to identify a differential effect of sleep deprivation on brain bioenergetics, cognitive performance, and sleep between cocaine-dependent and healthy control participants. 14 healthy control and 8 cocaine-dependent participants experienced consecutive nights of baseline, total sleep deprivation, and recovery sleep in the research laboratory. Participants underwent [31]P magnetic resonance spectroscopy (MRS) brain imaging, polysomnography, Continuous Performance Task, and Digit Symbol Substitution Task. Following recovery sleep, [31]P MRS scans revealed that cocaine-dependent participants exhibited elevated global brain β-NTP (direct measure of adenosine triphosphate), α-NTP, and total NTP levels compared to those of healthy controls. Cocaine-dependent participants performed worse on the Continuous Performance Task and Digit Symbol Substitution Task at baseline compared to healthy control participants, but sleep deprivation did not worsen cognitive performance in either group. Enhancements of brain ATP levels in cocaine dependent participants following recovery sleep may reflect a greater impact of sleep deprivation on sleep homeostasis, which may highlight the importance of monitoring sleep during abstinence and the potential influence of sleep loss in drug relapse. PMID:24250276

  14. Sleep restores loss of generalized but not rote learning of synthetic speech.

    Science.gov (United States)

    Fenn, Kimberly M; Margoliash, Daniel; Nusbaum, Howard C

    2013-09-01

    Sleep-dependent consolidation has been demonstrated for declarative and procedural memory but few theories of consolidation distinguish between rote and generalized learning, suggesting similar consolidation should occur for both. However, studies using rote and generalized learning have suggested different patterns of consolidation may occur, although different tasks have been used across studies. Here we directly compared consolidation of rote and generalized learning using a single speech identification task. Training on a large set of novel stimuli resulted in substantial generalized learning, and sleep restored performance that had degraded after 12 waking hours. Training on a small set of repeated stimuli primarily resulted in rote learning and performance also degraded after 12 waking hours but was not restored by sleep. Moreover performance was significantly worse 24-h after rote training. Our results suggest a functional dissociation between the mechanisms of consolidation for rote and generalized learning which has broad implications for memory models. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Influence of Flow Velocity on Tsunami Loss Estimation

    Directory of Open Access Journals (Sweden)

    Jie Song

    2017-11-01

    Full Text Available Inundation depth is commonly used as an intensity measure in tsunami fragility analysis. However, inundation depth cannot be taken as the sole representation of tsunami impact on structures, especially when structural damage is caused by hydrodynamic and debris impact forces that are mainly determined by flow velocity. To reflect the influence of flow velocity in addition to inundation depth in tsunami risk assessment, a tsunami loss estimation method that adopts both inundation depth and flow velocity (i.e., bivariate intensity measures in evaluating tsunami damage is developed. To consider a wide range of possible tsunami inundation scenarios, Monte Carlo-based tsunami simulations are performed using stochastic earthquake slip distributions derived from a spectral synthesis method and probabilistic scaling relationships of earthquake source parameters. By focusing on Sendai (plain coast and Onagawa (ria coast in the Miyagi Prefecture of Japan in a case study, the stochastic tsunami loss is evaluated by total economic loss and its spatial distribution at different scales. The results indicate that tsunami loss prediction is highly sensitive to modelling resolution and inclusion of flow velocity for buildings located less than 1 km from the sea for Sendai and Onagawa of Miyagi Prefecture.

  16. Can We Predict Cognitive Performance Decrements Due to Sleep Loss and the Recuperative Effects of Caffeine

    Science.gov (United States)

    2015-10-14

    the integrated UMP would provide another step toward the development of a wearable computer-based system or smartphone app that considers an......mail.mil ABSTRACT Warfighters are often subjected to challenging sleep/wake schedules that hinder their cognitive performance. Countermeasures

  17. Evaluating the Workload of On-Call Psychiatry Residents: Which Activities Are Associated with Sleep Loss?

    Science.gov (United States)

    Cooke, Brian K.; Cooke, Erinn O.; Sharfstein, Steven S.

    2012-01-01

    Objective: The purpose of this study was to review the workload inventory of on-call psychiatry residents and to evaluate which activities were associated with reductions in on-call sleep. Method: A prospective cohort study was conducted, following 20 psychiatry residents at a 231-bed psychiatry hospital, from July 1, 2008 through June 30, 2009.…

  18. Strain differences in the influence of open field exposure on sleep in mice.

    Science.gov (United States)

    Tang, Xiangdong; Xiao, Jihua; Liu, Xianling; Sanford, Larry D

    2004-09-23

    The open field (OF) is thought to induce anxiety in rodents. It also allows an opportunity for exploration in a novel environment. Less activity in the OF is thought to indicate greater anxiety whereas more activity may reflect greater exploration, and possibly greater exploratory learning. Anxiety and learning have poorly understood relationships to sleep. In order to determine how anxiety and exploration in the OF could influence sleep, we recorded sleep in mouse strains (C57BL/6J (B6), BALB/cJ (C), DBA/2J (D2), and CB6F1/J (CB6)) with different levels of anxiety and exploration after 30 min in an OF. In all strains, OF exposure induced immediate decreases in rapid eye movement sleep (REM) followed by longer latency increases in REM. The time course and amount of REM decreases and increases varied among strains. Compared to less anxious B6, D2 and CB6 mice, C mice had greater and longer lasting immediate decreases in REM. C mice also displayed longer periods of decreases REM and a smaller, longer latency increase in REM. OF exploratory activity was positively correlated to percentage of REM increases from 6 to 10h after OF exposure. The results suggest that the anxiogenic component of the OF produced an immediate decrease in REM that was greater in more "anxious" mice. In contrast, exploration in the OF was associated with increased REM, with the increase greater in less anxious mice. The results are discussed with respect to the potential influences of anxiety and learning on sleep.

  19. Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation.

    Science.gov (United States)

    Lee, Michael L; Katsuyama, Ângela M; Duge, Leanne S; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J; de la Iglesia, Horacio O

    2016-11-01

    Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation. © 2016 Associated Professional Sleep Societies, LLC.

  20. The effects of sleep restriction and sleep deprivation in producing false memories.

    Science.gov (United States)

    Chatburn, Alex; Kohler, Mark J; Payne, Jessica D; Drummond, Sean P A

    2017-01-01

    False memory has been claimed to be the result of an associative process of generalisation, as well as to be representative of memory errors. These can occur at any stage of memory encoding, consolidation, or retrieval, albeit through varied mechanisms. The aim of this paper is to experimentally determine: (i) if cognitive dysfunction brought about by sleep loss at the time of stimulus encoding can influence false memory production; and (ii) whether this relationship holds across sensory modalities. Subjects undertook both the Deese-Roedigger-McDermott (DRM) false memory task and a visual task designed to produce false memories. Performance was measured while subjects were well-rested (9h Time in Bed or TIB), and then again when subjects were either sleep restricted (4h TIB for 4 nights) or sleep deprived (30h total SD). Results indicate (1) that partial and total sleep loss produced equivalent effects in terms of false and veridical verbal memory, (2) that subjects performed worse after sleep loss (regardless of whether this was partial or total sleep loss) on cued recognition-based false and veridical verbal memory tasks, and that sleep loss interfered with subjects' ability to recall veridical, but not false memories under free recall conditions, and (3) that there were no effects of sleep loss on a visual false memory task. This is argued to represent the dysfunction and slow repair of an online verbal associative process in the brain following inadequate sleep. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Sleep dysfunctions influence decision making in undemented Parkinson's disease patients: a study in a virtual supermarket.

    Science.gov (United States)

    Albani, Giovanni; Raspelli, Simona; Carelli, Laura; Priano, Lorenzo; Pignatti, Riccardo; Morganti, Francesca; Gaggioli, Andrea; Weiss, Patrice L; Kizony, Rachel; Katz, Noomi; Mauro, Alessandro; Riva, Giuseppe

    2011-01-01

    In the early-middle stages of Parkinson's disease (PD), polysomnographic studies show early alterations of the structure of the sleep, which may explain frequent symptoms reported by patients, such as daytime drowsiness, loss of attention and concentration, feeling of tiredness. The aim of this study was to verify if there is a correlation between the sleep dysfunction and decision making ability. We used a Virtual Reality version of the Multiple Errand Test (VMET), developed using the NeuroVR free software (http://www.neurovr2.org), to evaluate decision-making ability in 12 PD not-demented patients and 14 controls. Five of our not-demented 12 PD patients showed abnormalities in the polysomnographic recordings associated to significant differences in the VMET performance.

  2. Role of Sex and the Environment in Moderating Weight Gain Due to Inadequate Sleep.

    Science.gov (United States)

    Coborn, Jamie E; Houser, Monica M; Perez-Leighton, Claudio E; Teske, Jennifer A

    2017-12-01

    The growing prevalence of obesity, inadequate sleep and sleep disorders together with the negative impact of lack of sleep on overall health highlights the need for therapies targeted towards weight gain due to sleep loss. Sex disparities in obesity and sleep disorders are present; yet, the role of sex is inadequately addressed and thus it is unclear whether sensitivity to sleep disruption differs between men and women. Like sex, environmental factors contribute to the development of obesity and poor sleep. The obesogenic environment is characterized by easy access to palatable foods and a low demand for energy expenditure in daily activities. These and other environmental factors are discussed, as they drive altered sleep or their interaction with food choice and intake can promote obesity. We discuss data that suggest differences in sleep patterns and responses to sleep disruption influence sex disparities in weight gain, and that enviromental disturbances alter sleep and interact with features of the obesogenic environment that together promote obesity.

  3. Neural activation within components of verbal working memory following sleep loss

    OpenAIRE

    McKenna, Benjamin Scott

    2011-01-01

    Total sleep deprivation (TSD) leads to neurobehavioral changes in experimental tasks of alertness, attention, learning, and motor responses. However, results from working memory (WM) studies are more equivocal. WM comprises multiple cognitive processes and the cerebral basis of this differential vulnerability is not known. The current experiment utilized tasks employing parametric manipulations within an event-related functional magnetic resonance imaging (fMRI) design to better understand th...

  4. Changes in Regional Adiposity and Cardio-Metabolic Function Following a Weight Loss Program with Sibutramine in Obese Men with Obstructive Sleep Apnea

    Science.gov (United States)

    Phillips, Craig L.; Yee, Brendon J.; Trenell, Mike I.; Magnussen, John S.; Wang, David; Banerjee, Dev; Berend, Norbert; Grunstein, Ronald R.

    2009-01-01

    Background: Although obstructive sleep apnea (OSA) is strongly linked with obesity, both conditions have been associated with increased cardiovascular risk including glucose intolerance, dyslipidemia, and hypertension independent of one another. Weight loss is known to improve both cardiovascular risk and OSA severity. The aim of this study was to evaluate cardiovascular and metabolic changes, including compartment-specific fat loss in obese OSA subjects undergoing a weight loss program. Design: Observational study. Participants: 93 men with moderate-severe OSA. Interventions: 6-month open-label weight loss trial combining sibutramine (a serotonin and noradrenaline reuptake inhibitor) with a 600-kcal deficit diet and exercise. Measurements and Results: At baseline and following 6 months of weight loss, OSA was assessed together with CT-quantified intra-abdominal and liver fat and markers of metabolic and cardiovascular function. At 6 months, weight loss and improvements in OSA were accompanied by improved insulin resistance (HOMA), increased HDL cholesterol, and reduced total cholesterol/HDL ratio. There were also reductions in measures of visceral and subcutaneous abdominal fat and liver fat. Reductions in liver fat and sleep time spent below 90% oxyhemoglobin saturation partly explained the improvement in HOMA (R2 = 0.18). In contrast, arterial stiffness (aortic augmentation index), heart rate, blood pressure, and total cholesterol did not change. Conclusions: Weight loss with sibutramine was associated with improvements in metabolic and body composition risk factors but not blood pressure or arterial stiffness. Improved insulin resistance was partly associated with reductions in liver fat and hypoxemia associated with sleep apnea. Citation: Phillips CL; Yee BJ; Trenell MI; Magnussen JS; Wang D; Banerjee D; Berend N; Grunstein RR. Changes in regional adiposity and cardio-metabolic function following a weight loss program with sibutramine in obese men with

  5. Modulating influences of memory strength and sensitivity of the retrieval test on the detectability of the sleep consolidation effect.

    Science.gov (United States)

    Schoch, Sarah F; Cordi, Maren J; Rasch, Björn

    2017-11-01

    Emotionality can increase recall probability of memories as emotional information is highly relevant for future adaptive behavior. It has been proposed that memory processes acting during sleep selectively promote the consolidation of emotional memories, so that neutral memories no longer profit from sleep consolidation after learning. This appears as a selective effect of sleep for emotional memories. However, other factors contribute to the appearance of a consolidation benefit and influence this interpretation. Here we show that the strength of the memory trace before sleep and the sensitivity of the retrieval test after sleep are critical factors contributing to the detection of the benefit of sleep on memory for emotional and neutral stimuli. 228 subjects learned emotional and neutral pictures and completed a free recall after a 12-h retention interval of either sleep or wakefulness. We manipulated memory strength by including an immediate retrieval test before the retention interval in half of the participants. In addition, we varied the sensitivity of the retrieval test by including an interference learning task before retrieval testing in half of the participants. We show that a "selective" benefit of sleep for emotional memories only occurs in the condition with high memory strength. Furthermore, this "selective" benefit disappeared when we controlled for the memory strength before the retention interval and used a highly sensitive retrieval test. Our results indicate that although sleep benefits are more robust for emotional memories, neutral memories similarly profit from sleep after learning when more sensitive indicators are used. We conclude that whether sleep benefits on memory appear depends on several factors, including emotion, memory strength and sensitivity of the retrieval test. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Disruption of adolescents' circadian clock: The vicious circle of media use, exposure to light at night, sleep loss and risk behaviors.

    Science.gov (United States)

    Touitou, Yvan; Touitou, David; Reinberg, Alain

    2016-11-01

    Although sleep is a key element in adolescent development, teens are spending increasing amounts of time online with health risks related to excessive use of electronic media (computers, smartphones, tablets, consoles…) negatively associated with daytime functioning and sleep outcomes. Adolescent sleep becomes irregular, shortened and delayed in relation with later sleep onset and early waking time due to early school starting times on weekdays which results in rhythm desynchronization and sleep loss. In addition, exposure of adolescents to the numerous electronic devices prior to bedtime has become a great concern because LEDs emit much more blue light than white incandescent bulbs and compact fluorescent bulbs and have therefore a greater impact on the biological clock. A large number of adolescents move to evening chronotype and experience a misalignment between biological and social rhythms which, added to sleep loss, results in e.g. fatigue, daytime sleepiness, behavioral problems and poor academic achievement. This paper on adolescent circadian disruption will review the sensitivity of adolescents to light including LEDs with the effects on the circadian system, the crosstalk between the clock and the pineal gland, the role of melatonin, and the behavior of some adolescents(media use, alcohol consumption, binge drinking, smoking habits, stimulant use…). Lastly, some practical recommendations and perspectives are put forward. The permanent social jet lag resulting in clock misalignment experienced by a number of adolescents should be considered as a matter of public health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Mini-KiSS Online: an Internet-based intervention program for parents of young children with sleep problems – influence on parental behavior and children's sleep

    Directory of Open Access Journals (Sweden)

    Schlarb AA

    2012-03-01

    Full Text Available Angelika A Schlarb1,2,*, Isabel Brandhorst1,* 1University of Tuebingen, Faculty of Science, Department of Psychology, Tuebingen, 2University of Koblenz-Landau, Department of Psychology, Landau, Germany*The authors contributed equally to this workPurpose: Behavioral sleep problems are highly common in early childhood. These sleep problems have a high tendency to persist, and they may have deleterious effects on early brain development, attention, and mood regulation. Furthermore, secondary effects on parents and their relationship are documented. Negative parental cognition and behavior have been found to be important influencing factors of a child's behavioral sleep problems. Therefore, in the current study we examined the acceptance and efficacy of a newly developed Internet-based intervention program called Mini-KiSS Online for sleep disturbances for children aged 6 months to 4 years and their parents.Patients and methods: Fifty-five children (54.54% female; aged 8–57 months suffering from psychophysiological insomnia or behavioral insomnia participated in the 6-week online treatment. Sleep problems and treatment acceptance were examined with a sleep diary, anamnestic questionnaires, a child behavior checklist (the Child Behavior Checklist 1.5–5, and treatment evaluation questionnaires.Results: The evaluation questionnaires showed a high acceptance of Mini-KiSS Online. Parents would recommend the treatment to other families, were glad to participate, and reported that they were able to deal with sleep-related problems of their child after Mini-KiSS Online. Parental behavior strategies changed with a reduction of dysfunctional strategies, such as staying or soothing the child until they fell asleep, allowing the child to get up again and play or watch TV, or reading them another bedtime story. Frequency and duration of night waking decreased as well as the need for external help to start or maintain sleep. All parameters changed

  8. The influence of upper airways diameter on the intensity of obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Jolanta Szymańska

    2014-03-01

    Full Text Available Introduction and Objective. Obstructive sleep apnea (OSA is characterized by at least 5 ten-second-long episodes of apnea or hypopnea, per hour of sleep. This disease may lead to severe, life-threatening complications. Therefore, risk analysis and its influence on disease intensity is crucial for proper implementation of preventive treatments. Objective. To determine the relation between the intensity of OSA expressed in Apnea-Hypopnea Index (AHI, and the anterior-posterior diameter of upper airways at the levels of soft palate and tongue base. Material and Method. Medical records of 41 patients with sleep apnea (AHI>4 diagnosed through polysomnographic examination obstructive were used for the study. The data consisted of: age and gender, polysomnographic examination results (AHI, lateral cephalogram with cephalomertic analysis, together with measurements of the upper and lower pharyngeal depth according to McNamara. Statistical analysis was carried out in accordance with Pearson’s r correlation coefficient test (Statistica 8.0 software package. Results. Analysis of the influence of upper airways diameter on the intensity of OSA showed that the value of upper Airways diameter at the tongue base level had no statistically significant impact on the value of AHI (p=0.795. However, a statistically significant impact of the value of upper airways diameter on the AHI value (p=0.008 at the soft palate level was observed. Patients with OSA have narrowed upper airways diameter. The value of AHI increases with the decrease of upper diameter and is not dependent on a lower diameter value. Patients with a decreased upper airways diameter should be informed about potential breathing disorders during sleep.

  9. The influence of autonomic interventions on the sleep-wake-related changes in gastric myoelectrical activity in rats.

    Science.gov (United States)

    Huang, Y M; Yang, C C H; Lai, C J; Kuo, T B J

    2011-06-01

    Significant changes in autonomic activity occur at sleep-wake transitions and constitute an ideal setting for investigating the modulatory role of the autonomic nervous system on gastric myoelectrical activity (GMA). Using continuous power spectral analysis of electroencephalogram, electromyogram, and electrogastromyogram (EGMG) data from freely moving rats that had undergone chemical sympathetomy and/or truncal vagotomy, sleep-wake-related fluctuations in GMA were compared among the intervention groups. The pattern and extent of fluctuations in EGMG power across the sleep-wake states was blunted most significantly in rats undergoing both chemical sympathectomy and truncal vagotomy. The effect of these interventions also varied with respect to the transition between different sleep-wake states. The most prominent influences were observed between active waking and quiet sleep and between paradoxical sleep and quiet sleep. The sleep-wake-related fluctuations in EGMG power are a result of joint contributions from both sympathetic and vagal innervation. Vagotomy mainly resulted in a reduction in EGMG power, while the role of sympathetic innervation was unveiled by vagotomy and this was reflected most obviously in the extent of the fluctuations in EGMG power. © 2011 Blackwell Publishing Ltd.

  10. Sleep and menopause: a narrative review.

    Science.gov (United States)

    Shaver, Joan L; Woods, Nancy F

    2015-08-01

    Our overall aim-through a narrative review-is to critically profile key extant evidence of menopause-related sleep, mostly from studies published in the last decade. We searched the database PubMed using selected Medical Subject Headings for sleep and menopause (n = 588 articles). Using similar headings, we also searched the Cochrane Library (n = 1), Embase (n = 449), Cumulative Index to Nursing and Allied Health Literature (n = 163), Web of Science (n = 506), and PsycINFO (n = 58). Articles deemed most related to the purpose were reviewed. Results were articulated with interpretive comments according to evidence of sleep quality (self-reported) and sleep patterns (polysomnography and actigraphy) impact as related to reproductive aging and in the context of vasomotor symptoms (VMS; self-reported), vasomotor activity (VMA) events (recorded skin conductance), depressed mood, and ovarian hormones. Predominantly, the menopausal transition conveys poor sleep beyond anticipated age effects. Perceptions of sleep are not necessarily translatable from detectable physical sleep changes and are probably affected by an emotional overlay on symptoms reporting. Sleep quality and pattern changes are mostly manifest in wakefulness indicators, but sleep pattern changes are not striking. Likely contributing are VMS of sufficient frequency/severity and bothersomeness, probably with a sweating component. VMA events influence physical sleep fragmentation but not necessarily extensive sleep loss or sleep architecture changes. Lack of robust connections between perceived and recorded sleep (and VMA) could be influenced by inadequate detection. There is a need for studies of women in well-defined menopausal transition stages who have no sleep problems, accounting for sleep-related disorders, mood, and other symptoms, with attention to VMS dimensions, distribution of VMS during night and day, and advanced measurement of symptoms and physiologic manifestations.

  11. Influence of cilazapril on memory functions and sleep behaviour in comparison with metoprolol and placebo in healthy subjects.

    Science.gov (United States)

    Dietrich, B; Herrmann, W M

    1989-01-01

    1. In a controlled, randomized, double-blind study the influence of cilazapril and metoprolol on learning and memory functions and on sleep behaviour was investigated in healthy young volunteers under steady-state conditions. Twenty-three subjects were given either 2.5 mg cilazapril, 200 mg metoprolol, or placebo for 14 days in a latin square design separated by washout periods of 7 days. 2. To test memory functions different modalities--verbal, visual, numerical associative and two dimensional spatial memory were tested for recent anterograde recall, both short-term (less than 10 s) and middle-term (up to 15 min) were selected. The test had a content similar to that used in daily life situations. The sleep behaviour was tested both by objective (all night sleep EEG) and subjective measures. 3. Neither antihypertensive drug had an observable influence on memory performance at the dosages used under steady-state conditions. However, sleep was disturbed during metoprolol, while cilazapril could not be differentiated from placebo. The effects of metoprolol on sleep behaviour were observed in the objective and subjective measures. There was more frequent awakening during the night with the subjective complaint of difficulties in sleeping through. 4. From this study it is concluded that cilazapril has no major effect on memory functions and sleep behaviour. This is only true for the dosages given and under steady-state conditions.

  12. Influence of the storage conditions on prestressing steel relaxation losses

    Directory of Open Access Journals (Sweden)

    Suárez, F.

    2012-12-01

    Full Text Available Stress relaxation losses on active reinforcement have significant impact on prestressed concrete structures. This is why relaxation tests are carried out on prestressing steel wires and strands after being manufactured. Then, these materials are coiled and stored for a long-term period, sometimes in excess of one year. The influence of these operations, carried out after manufacturing, is usually neglected. Nevertheless, some manufacturers and contractors have noticed that, sometimes, when relaxation tests are carried out after a long-term storage, the relaxation losses found are higher than those measured immediately after manufacturing. In this work, lab tests are performed to check the influence of the coiling radius and the period of storage on the relaxation test. In addition to this, an analytical model is presented to predict the results of a relaxation test carried out on a wire coiled and stored for a long-term period. This model explains the evolution on the cross-sectional stress profile along the coiling-storing-uncoiling process, as well as the influence of the residual stresses on it.

    La pérdida de tensión por relajación en las armaduras activas afecta de forma importante a las estructuras de hormigón pretensado. Por ello se realizan ensayos de relajación de los alambres y cordones de pretensado tras su fabricación. Después, el material es enrollado y almacenado durante periodos que en ocasiones pueden superar el año de duración. Generalmente se desprecia la influencia que estas operaciones posteriores a la fabricación pueden tener sobre el material. Sin embargo, diversos fabricantes y suministradores han constatado experimentalmente que, en ocasiones, el material almacenado durante un periodo prolongado presenta pérdidas de relajación mayores que inmediatamente tras su fabricación. En este trabajo se realizan ensayos de laboratorio para comprobar la influencia que el radio de enrollamiento y el periodo de

  13. Sleep deprivation: a mind-body approach.

    Science.gov (United States)

    Aguirre, Claudia C

    2016-11-01

    The purpose of this review is to summarize recent advances in our understanding of the impact sleep disturbances have on our health, with particular focus on the brain. The present review considers the influence of sleep disturbance on the neurovascular unit; the role of sleep disturbance in neurodegenerative diseases; and relevant strategies of neuro-immuno-endocrine interactions that likely contribute to the restorative power of sleep. Given the latest discoveries about the brain's waste clearance system and its relationship to neurodegenerative diseases like Alzheimer's disease, this review gives a brief overview on the molecular mechanisms behind sleep loss-related impairments. Recent evidence indicates that sleep plays a vital role in neuro-immuno-endocrine homeostasis. Sleep loss has been linked to elevated risks for cognitive and mood disorders, underscored by impaired synaptic transmission. The glymphatic system has been shown to be modulated by sleep and implicated in neurodegenerative disorders. Interactions between sleep quality, the immune system, and neurodegenerative disease are complex and a challenge to distil. These interactions are frequently bidirectional, because of sleep's characterization as an early symptom and as a potential factor contributing to the development and progression of mood and cognitive disorders. VIDEO ABSTRACT.

  14. Influence of Sleep Disturbances on Quality of Life of Iranian Menopausal Women

    Directory of Open Access Journals (Sweden)

    Zohreh Yazdi

    2013-01-01

    Full Text Available Background. Subjective sleep disturbances increase during menopause. Some problems commonly encountered during menopause, such as hot flushes and sweating at night, can cause women to have difficulty in sleeping. These complaints can influence quality of life of menopausal women. Methods. This cross-sectional study was performed on menopausal women attending health centers in Qazvin for periodic assessments. We measured excessive daytime sleepiness by Epworth sleepiness scale (ESS, obstructive sleep apnea (OSA by the Berlin questionnaire, and insomnia by the insomnia severity index (ISI. We evaluate quality of life by the Menopause specific quality of life questionnaire (MENQOL. Results. A total of 380 menopausal women entered the study. Mean age of participated women was 57.6 ± 6.02. Mean duration of menopause was 6.3 ± 4.6. The frequency of severe and moderate insomnia was 8.4% (32 and 11.8% (45. Severe daytime sleepiness (ESS ≥ 10 was present in 27.9% (80 of the participants. Multivariate analytic results show that insomnia and daytime sleepiness have independent negative impact on each domain and total score of MENQOL questionnaire. Conclusion. According to our findings, EDS and insomnia are frequent in menopausal women. Both EDS and insomnia have significant quality of life impairment.

  15. Can physical activity influence the quality of sleep among the elderly?

    OpenAIRE

    Podhorecka, Marta; Cytarska, Magdalena; Gębka, Dominika; Perkowski, Radosław; Androsiuk-Perkowska, Joanna; Jaroch, Alina; Siedlecka-Główczewska, Emilia; Sokołowski, Remigiusz; Zukow, Walery; Kędziora-Kornatowska, Kornelia

    2017-01-01

    Podhorecka Marta, Cytarska Magdalena, Gębka Dominika, Perkowski Radosław, Androsiuk-Perkowska Joanna, Jaroch Alina, Siedlecka–Główczewska Emilia, Sokołowski Remigiusz, Zukow Walery, Kędziora-Kornatowska Kornelia. Can physical activity influence the quality of sleep among the elderly? Journal of Education, Health and Sport. 2017;7(12):288-305. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.1133730 http://ojs.ukw.edu.pl/index.php/johs/article/view/5177 ...

  16. Circadian Rhythms, Sleep Deprivation, and Human Performance

    Science.gov (United States)

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

    2014-01-01

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

  17. The periodicity of sleep duration – an infradian rhythm in spontaneous living

    OpenAIRE

    Wong, Shi Ngar; Halaki,Mark; Chow,Chin Moi

    2013-01-01

    Shi Ngar Wong, Mark Halaki, Chin Moi ChowDiscipline of Exercise and Sport Science, University of Sydney, Sydney, NSW, AustraliaAbstract: The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults u...

  18. Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

    KAUST Repository

    Tay-Wo-Chong, Luis; Zellhuber, Mathieu; Komarek, Thomas; Im, Hong G.; Polifke, Wolfgang

    2015-01-01

    relation in terms of Markstein number, Karlovitz Number and a non-dimensional heat loss parameter was proposed for the combined influence of strain and heat losses on the consumption speed. Combining this empirical relation with a presumed probability

  19. Weight loss and brown adipose tissue reduction in rat model of sleep apnea

    Directory of Open Access Journals (Sweden)

    de Oliveira Patricia G

    2008-07-01

    Full Text Available Abstract Background - Obesity is related to obstructive sleep apnea-hypopnea syndrome (OSAHS, but its roles in OSAHS as cause or consequence are not fully clarified. Isocapnic intermittent hypoxia (IIH is a model of OSAHS. We verified the effect of IIH on body weight and brown adipose tissue (BAT of Wistar rats. Methods Nine-month-old male breeders Wistar rats of two groups were studied: 8 rats submitted to IIH and 5 control rats submitted to sham IIH. The rats were weighed at the baseline and at the end of three weeks, after being placed in the IIH apparatus seven days per week, eight hours a day, in the lights on period, simulating an apnea index of 30/hour. After experimental period, the animals were weighed and measured as well as the BAT, abdominal, perirenal, and epididymal fat, the heart, and the gastrocnemius muscle. Results Body weight of the hypoxia group decreased 17 ± 7 grams, significantly different from the variation observed in the control group (p = 0,001. The BAT was 15% lighter in the hypoxia group and reached marginally the alpha error probability (p = 0.054. Conclusion Our preliminary results justify a larger study for a longer time in order to confirm the effect of isocapnic intermittent hypoxia on body weight and BAT.

  20. Sleep Sleeping Patch

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Sleep Sleeping Patch is a new kind of external patch based on modern sleep medicine research achievements, which uses the internationally advanced transdermal therapeutic system (TTS). The Sleep Sleeping Patch transmits natural sleep inducers such as peppermint and liquorice extracts and melatonin through the skin to induce sleep. Clinical research proves that the Sleep Sleeping Patch can effectively improve insomnia and the quality of sleep. Highly effective: With the modern TTS therapy,

  1. Original Article Blood Loss and Influencing Factors in Primary Total ...

    African Journals Online (AJOL)

    KIGZ

    aid the surgeon in the African region estimate the expected blood loss after total hip replacement. We conducted a study to quantify the blood loss following total hip arthroplasty and to determine the factors .... Hemoglobin European Overview (OSTHEO) study: blood management in elective knee and hip arthroplasty in ...

  2. Impact of a Mindfulness-Based Weight-Loss Intervention on Sleep Quality Among Adults with Obesity: Data from the SHINE Randomized Controlled Trial.

    Science.gov (United States)

    Adler, Elizabeth; Dhruva, Anand; Moran, Patricia J; Daubenmier, Jennifer; Acree, Michael; Epel, Elissa S; Bacchetti, Peter; Prather, Aric A; Mason, Ashley; Hecht, Frederick M

    2017-03-01

    Sleep disturbance is a common problem among adults with obesity. Mindfulness interventions have been shown to improve sleep quality in various populations but have not been investigated in adults with obesity. The aim of this study was to compare the effects of a mindfulness-based weight-loss intervention with an active control on self-reported sleep quality among adults with obesity. This study was a secondary analysis of a randomized controlled trial and included 194 adults with a body mass index in the range 30-45 kg/m 2 . The treatment intervention included mindfulness-based eating and stress-management practices, and the active control intervention included training in progressive muscle relaxation (PMR). Both groups received identical diet and exercise guidelines in 17 group sessions conducted over 5.5 months that were matched for time, attention, and social support. The primary outcome of this analysis was between-group change in self-reported sleep quality, which was assessed using the Pittsburgh Sleep Quality Index (PSQI) global score at baseline and at 6, 12, and 18 months. Between-group differences in mean PSQI change scores in the mindfulness group (n = 100) compared to the control group (n = 94) were -0.27 (-0.68, 1.22; p = 0.58) at 6 months, -0.57 (-0.35, 1.50; p = 0.22) at 12 months, and -0.50 (-0.53, 1.53; p = 0.34) at 18 months, all in the direction of more sleep improvement in the mindfulness group but none reaching statistical significance. In the mindfulness group, average weekly minutes of meditation practice time was associated with improved sleep quality from baseline to 6 months. No statistically significant evidence was found that a weight-loss program that incorporates mindfulness improves self-reported sleep quality compared to a control diet/exercise intervention that included PMR. Within the mindfulness group, average weekly minutes of mindfulness practice was associated with improved sleep quality.

  3. Energetic constraints, not predation, influence the evolution of sleep patterning in mammals

    OpenAIRE

    Capellini, I.; Nunn, C. L.; McNamara, P.; Preston, B. T.; Barton, R. A.

    2008-01-01

    Mammalian sleep is composed of two distinct states – rapid-eye-movement (REM) and non-REM (NREM) sleep – that alternate in cycles over a sleep bout. The duration of these cycles varies extensively across mammalian species. Because the end of a sleep cycle is often followed by brief arousals to waking, a shorter sleep cycle has been proposed to function as an anti-predator strategy. Similarly, higher predation risk could explain why many species exhibit a polyphasic sleep pattern (division of ...

  4. [Influencing factors of visual hallucinations in patients with Parkinson's disease and its relationship with sleep disorders].

    Science.gov (United States)

    Wu, D D; Li, S H; Jin, L Y; Jin, Y; Cui, Y Y; Zhao, H; Liu, H J; Ma, X X; Su, W; Chen, H B

    2016-04-05

    To investigate the prevalence and influencing factors of visual hallucinations in patients with Parkinson's disease(PD), and to analyze the relationship between visual hallucinations and sleep disorders. We recruited 187 patients with PD(H-Y Ⅰ-Ⅲ) from outpatient department in Beijing Hospital. The patients were investigated for general information and the use of medicine. The patients were divided into visual hallucination(VH) group and non-hallucination(non-VH) group. A comparison study was conducted between two groups. We investigated the sleep disorders of PD patients according to Non Motor Symptom Quest(NMSquest) and Parkinson's disease sleep scale(PDSS). Logistic stepwise multiple regression procedures were used to determine the best predictive model of visual hallucinations in patients with PD. (1) 42 cases(22.5%) of PD patients were accompanied by visual hallucinations; (2) the VH group and non-VH group had no difference in age, sex, duration of illness, the scores of Minimum Mental State Examination(MMSE) and levodopa equivalent doses (LED). The scores of Unified Parkinson's Disease Rating Scale(UPDRS) Ⅰ, the Hamilton Rating Scale for Anxiety(HAMA) and the Hamilton Rating Scale for Depression(HAMD) in VH group were significantly higher than those in non-VH group[3.5(2, 5) vs 2 (1, 3); 10(6.75, 15) vs 8(5, 11); 11(7.75, 17) vs 9(5, 13); Psleep behavior disorder(RBD) in VH group were significantly higher than those in non-VH group(61.9% vs 40.7%, 71.4% vs 47.6%, P0.05). The score of PDSS in VH group was significantly lower than that in non-VH group[111(92.75, 128.25) vs 123(109, 135), Psleep disorder are independently associated with VH in PD.

  5. Study Protocol: The influence of Running Therapy on executive functions and sleep of prisoners [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Jesse Meijers

    2015-06-01

    Full Text Available Background: Executive dysfunction appears to be related to increased recidivism. Of note is that sleep disturbances, which are highly prevalent in prisons, may attenuate executive functions. Thus, improving executive functions, either directly or indirectly through the improvement of sleep, may reduce recidivism. It is hypothesised that physical exercise, in the form of Running Therapy, has a direct positive effect on executive functions as well as an indirect effect through the improvement of sleep. Methods/Design: Seventy two (N = 72 detainees in various penitentiary institutions in the Netherlands will be recruited in this study. A baseline measurement, including six neuropsychological tests of the Cambridge Neuropsychological Test Automated Battery (CANTAB, an assessment of sleep quality and duration using the Actiwatch (Actiwatch 2, Philips Respironics, Murrysville, PA, USA and various other measurements will be administered before the start of the treatment. After 3 months of Running Therapy, participants will be assessed again with the same tests for neuropsychological and physical functioning. Primary outcomes are executive functioning and various sleep variables. Discussion: This study will be the first to investigate the possible influence of Running Therapy on the cognitive functioning, sleep and aggression in prisoners.

  6. The study of grinding patterns and factors influencing the grinding areas during sleep bruxism.

    Science.gov (United States)

    Tao, Jianxiang; Liu, Weicai; Wu, Junhua; Zhang, Xuying; Zhang, Yongting

    2015-10-01

    The purpose of this study is to investigate the grinding patterns and discuss the factors influencing the position relationship between intercuspal position (ICP) and grinding area during sleep bruxism. Lateral condylar inclination, inclination of lateral incisal path and freedom in long centric of thirty subjects were measured. The grinding patterns during sleep bruxism were recorded with a bruxism recording device, BruxChecker. The position relationship between ICP and the grinding area was examined. Spearman's rank correlation coefficient was used for correlation analysis between grinding area and free factors (grinding patterns, freedom in long centric and discrepancy between lateral condylar inclination and inclination of lateral incisal path). All 12 subjects with 0mm-freedom in long centric exhibited that ICP of both sides located within the grinding areas. 4 subjects showed that ICP of both sides located outside the grinding areas. There is a significant correlation between 0mm-freedom in long centric and ICP within the grinding areas (p grinding area. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. The sleeping brain's influence on verbal memory: boosting resistance to interference.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Ellenbogen

    Full Text Available Memories evolve. After learning something new, the brain initiates a complex set of post-learning processing that facilitates recall (i.e., consolidation. Evidence points to sleep as one of the determinants of that change. But whenever a behavioral study of episodic memory shows a benefit of sleep, critics assert that sleep only leads to a temporary shelter from the damaging effects of interference that would otherwise accrue during wakefulness. To evaluate the potentially active role of sleep for verbal memory, we compared memory recall after sleep, with and without interference before testing. We demonstrated that recall performance for verbal memory was greater after sleep than after wakefulness. And when using interference testing, that difference was even more pronounced. By introducing interference after sleep, this study confirms an experimental paradigm that demonstrates the active role of sleep in consolidating memory, and unmasks the large magnitude of that benefit.

  8. Factors that influence disclosure of hearing loss in the workplace.

    Science.gov (United States)

    Southall, Kenneth; Jennings, Mary Beth; Gagné, Jean-Pierre

    2011-10-01

    The objective of the study was to identify factors that lead individuals to conceal or disclose their hearing loss in the workplace. A qualitative research paradigm called qualitative description was selected to address this issue. Twelve people who had an adult onset hearing loss, and were gainfully employed, participated in audio-recorded semi-structured interviews designed to probe issues related to disclosure of hearing loss. A photo elicitation interview technique was employed during the interviews. Content analyses were used to extract pertinent information from verbatim transcripts. Five recurring themes emerged as important considerations in relation to this topic: (1) perceived importance of the situation; (2) perceived sense of control; (3) community affiliation; (4) burden of communication; and (5) coexisting issues related to hearing loss. The findings are discussed in relation to other concealable stigmatizing traits, stigma-theory, and social-cognitive theory. The clinical implications of these findings are discussed, with particular emphasis placed on worker self-efficacy.

  9. On the need of objective vigilance monitoring: Effects of sleep loss on target detection and task-negative activity using combined EEG/fMRI

    Directory of Open Access Journals (Sweden)

    Michael eCzisch

    2012-04-01

    Full Text Available Sleep loss affects attention by reducing levels of arousal and alertness. The neural mechanisms underlying the compensatory efforts of the brain to maintain attention and performance after sleep deprivation are not fully understood. Previous neuroimaging studies of sleep deprivation have not been able to exclude the effects of reduced arousal and vigilance when examining cerebral responses to cognitive challenges. Here, we used a simultaneous electroencephalography (EEG and functional magnetic resonance imaging (fMRI approach to study the effects of 36 hours of total sleep deprivation (TSD. Specifically, we focused on changes in selective attention processes as induced by an active acoustic oddball task, with the ability to isolate runs with objective EEG signs of high or reduced vigilance. At high vigilance, task-related activity appears to be sustained by compensatory co-activation of insular regions, but task-negative activity in the right posterior node of the default mode network is altered following TSD. When EEG shows signs of reduced vigilance, task-positive activity was massively impaired, but task-negative activation was showing levels comparable with the control condition after a well-rested night. Our results suggest that loss of strict anti-correlation between task-positive and task-negative activation reflects the effects of TSD, while the actual state of vigilance and task performance either affects task-related or task-negative activity.

  10. Automatic Sleep Spindle Detection and Genetic Influence Estimation Using Continuous Wavelet Transform

    NARCIS (Netherlands)

    Adamczyk, M.; Genzel, L.K.E.; Dresler, M.; Steiger, A.; Friess, E.

    2015-01-01

    Mounting evidence for the role of sleep spindles in neuroplasticity has led to an increased interest in these non-rapid eye movement (NREM) sleep oscillations. It has been hypothesized that fast and slow spindles might play a different role in memory processing. Here, we present a new sleep spindle

  11. The influence of select losses components on induction squirrel-cage motor efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Dabala, K. [Electrical Machines Dept., Electrotechnical Inst., Warsaw (Poland)

    2000-07-01

    There is taken into consideration the influence of measured core and friction and windage losses on induction squirrel-cage motor in this paper. This paper presents a way of exact core losses determination in full-load motor. There are also compared efficiencies obtained for three core losses values: from no-load test (IEC 34-2); from draft IEC 2G/102/CDV; from presented in this paper method. This paper presents the influence of the friction and windage losses determined from no-load test and the mechanical losses appeared under the rated speed on the efficiency, too. There is compared the influence of the core and mechanical losses sum on the efficiency dependently on the way of this losses components determination. (orig.)

  12. Filament bundle location influence on coupling losses in superconducting composites

    International Nuclear Information System (INIS)

    Ito, Daisuke; Koizumi, Misao; Hamajima, Takataro; Nakane, Fumoto.

    1983-01-01

    The ac losses in multifilamentary superconducting composites with different superconducting filament bundle positions have been measured using the magnetization method in order to reveal the relation between filament bundle position and coupling losses. Loss components depending on dB/dt in a mixed matrix superconducting composite, whose filament bundle is located in a central region surrounded by an outer stabilizing copper sheath, has been compared with another superconducting composite whose stabilizing copper is located in a central region surrounded by an outer filament bundle. In both conductors, key parameters, such as filament twistpitch, wire diameter and amount of copper stabilizer, were almost the same. Applied magnetic field is 2 Tesla with 0.05-2 Tesla/sec field change rate. Experimental results indicate that coupling losses between filaments in the composite with the filament bundle located in the central region is smaller than the composite with the filament bundle located in the outer region. A similar conclusion was reached theoretically by B. Truck. Coupling loss values obtained by the experiment show good agreement with calculated values with the equations proposed by B. Truck. It is also pointed out that a copper stabilizer, divided by the CuNi barrier into small regions, like a honeycomb, causes anomalous increasing in the copper resistivity due to Ni diffusion during heat treatment. (author)

  13. The Somnolent Youth-Sleep and the Influence of Exercise: A Narrative Review

    Directory of Open Access Journals (Sweden)

    Haresh T. Suppiah

    2015-06-01

    Full Text Available Sleep is crucial to the physiological and psychological development of youth. The implications of insufficient sleep on learning and school performance are well documented. However, adequate sleep often goes unmet due to a combination of biological, societal, and environmental factors, especially during adolescence. In the present review, the changes to adolescent sleep patterns, and its consequences on cognition and learning are briefly explored. We then review the empirical literature of the role of exercise in regulating adolescent sleep patterns, and its potential mechanisms.

  14. Recovery from Unrecognized Sleep Loss Accumulated in Daily Life Improved Mood Regulation via Prefrontal Suppression of Amygdala Activity

    Directory of Open Access Journals (Sweden)

    Yuki Motomura

    2017-06-01

    Full Text Available Many modern people suffer from sleep debt that has accumulated in everyday life but is not subjectively noticed [potential sleep debt (PSD]. Our hypothesis for this study was that resolution of PSD through sleep extension optimizes mood regulation by altering the functional connectivity between the amygdala and prefrontal cortex. Fifteen healthy male participants underwent an experiment consisting of a baseline (BL evaluation followed by two successive interventions, namely, a 9-day sleep extension followed by one night of total sleep deprivation (TSD. Tests performed before and after the interventions included a questionnaire on negative mood and neuroimaging with arterial spin labeling MRI for evaluating regional cerebral blood flow (rCBF and functional connectivity. Negative mood and amygdala rCBF were significantly reduced after sleep extension compared with BL. The amygdala had a significant negative functional connectivity with the medial prefrontal cortex (FCamg–MPFC, and this negative connectivity was greater after sleep extension than at BL. After TSD, these indices reverted to the same level as at BL. An additional path analysis with structural equation modeling showed that the FCamg–MPFC significantly explained the amygdala rCBF and that the amygdala rCBF significantly explained the negative mood. These findings suggest that the use of our sleep extension protocol normalized amygdala activity via negative amygdala–MPFC functional connectivity. The resolution of unnoticed PSD may improve mood by enhancing frontal suppression of hyperactivity in the amygdala caused by PSD accumulating in everyday life.

  15. Sleep deprived and sweating it out: the effects of total sleep deprivation on skin conductance reactivity to psychosocial stress.

    Science.gov (United States)

    Liu, Jean C J; Verhulst, Silvan; Massar, Stijn A A; Chee, Michael W L

    2015-01-01

    We examined how sleep deprivation alters physiological responses to psychosocial stress by evaluating changes in skin conductance. Between-subjects design with one group allocated to 24 h of total sleep deprivation and the other to rested wakefulness. The study took place in a research laboratory. Participants were 40 healthy young adults recruited from a university. Sleep deprivation and feedback. Electrodermal activity was monitored while participants completed a difficult perceptual task with false feedback. All participants showed increased skin conductance levels following stress. However, compared to well-rested participants, sleep deprived participants showed higher skin conductance reactivity with increasing stress levels. Our results suggest that sleep deprivation augments allostatic responses to increasing psychosocial stress. Consequentially, we propose sleep loss as a risk factor that can influence the pathogenic effects of stress. © 2014 Associated Professional Sleep Societies, LLC.

  16. The role of emotional eating and stress in the influence of short sleep on food consumption.

    Science.gov (United States)

    Dweck, Julia S; Jenkins, Steve M; Nolan, Laurence J

    2014-01-01

    Short sleep duration is associated with elevated body mass index (BMI) and increased energy consumption. The present studies were conducted to determine what role emotional eating and stress might play in these relationships. The first was an exploratory questionnaire study in which sleep quality and duration were measured in conjunction with the Dutch Eating Behavior Questionnaire in 184 women. Emotional and external eating scores were significantly higher in those who reported poor sleep quality (but were not related to sleep duration). In a second study of 64 women who were provided with snacks in the laboratory under stressed and control conditions, elevated food consumption was observed in those who scored high on emotional eating and who reported short sleep (a significant stress × emotional eating × sleep duration interaction) but not in those who reported poor sleep quality. No effects were found in liking or wanting of food and few effects were found on appetite. BMI was not related to sleep duration or sleep quality in either study. The results suggest that the relationship between short sleep and elevated food consumption exists in those who are prone to emotional eating. An external stressor elevated consumption in normal sleepers to the level observed in short sleepers, however, it did not significantly elevate consumption in short sleepers. Future examinations of the effects of sleep duration and quality on food consumption should examine emotional eating status. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Influence of WeChat on sleep quality among undergraduates in Chongqing, China: a cross-sectional study

    OpenAIRE

    Xu, Xianglong; Lin, Qianyi; Zhang, Yan; Zhu, Runzhi; Sharma, Manoj; Zhao, Yong

    2016-01-01

    Background Previous studies showed that social media is associated with sleep quality. WeChat (a native social media in China) is very popular in China, especially among the youth. In the second quarter of 2016, Tencent?s WeChat had 806 million monthly active users. The study sought to identify the influence of WeChat on the sleep quality among undergraduate students. Methods A cross-sectional survey adopted a multi-stage stratified sampling survey to investigate undergraduates in Chongqing, ...

  18. Influence of Variable Fluid Properties and Radiative Heat loss on ...

    African Journals Online (AJOL)

    Consequently, comparative analysis is also performed on the wall shear stress and local heat transfer of the present study with the available results.The results show that the inclusion variable viscosity and thermal conductivity, and radiative heat loss mechanism cause significant effects on the fluid flow velocity, temperature ...

  19. Caffeine and energy drink use by combat arms soldiers in Afghanistan as a countermeasure for sleep loss and high operational demands.

    Science.gov (United States)

    McLellan, Tom M; Riviere, Lyndon A; Williams, Kelly W; McGurk, Dennis; Lieberman, Harris R

    2018-03-11

    Combat deployments are characterized by high operational demands with limited opportunities for sleep leading to fatigue and degraded cognitive and operational performance. Caffeine in moderate doses is recognized as an effective intervention for physical and cognitive decrements associated with sleep loss. This report is based on data collected by two separate, independently conducted surveys administered in Afghanistan in 2011-2012. It assessed caffeine use and sleep disruption among U.S. Army combat soldiers (J-MHAT 8; n = 518) and among deployed soldiers with different military assignments (USARIEM Deployment Survey; n = 260). Daily caffeine intake assessed in the J-MHAT 8 survey averaged 404 ± 18 mg. In the USARIEM Deployment Survey, intake was 303 ± 29 mg and was significantly higher among combat arms soldiers (483 ± 100 mg) compared to combat service support personnel (235 ± 23 mg). In both surveys, over 55% of total caffeine intake was from energy drinks. Additional sources of caffeine included coffee, tea, sodas, gum, candy, and over-the-counter medications. Higher caffeine intake was not associated with ability to fall asleep at night or wake-up in the morning (J-MHAT 8 survey). Higher caffeine consumption was associated with disrupted sleep from high operational tempo and nighttime duties of combat operations. Overall caffeine consumption and energy drink use in Afghanistan was greater than among non-deployed soldiers and civilians. Caffeine was frequently used as a countermeasure during night operations to offset adverse effects of sleep loss on physical and cognitive function, consistent with current Department of the Army recommendations.

  20. Factors influencing to earthquake caused economical losses on urban territories

    Science.gov (United States)

    Nurtaev, B.; Khakimov, S.

    2005-12-01

    Questions of assessment of earthquake economical losses on urban territories of Uzbekistan, taking into account damage forming factors, which are increqasing or reducing economical losses were discussed in the paper. Buildings and facilities vulnerability factors were classified. From total value (equal to 50) were selected most important ones. Factors ranging by level of impact and weight function in loss assessment were ranged. One group of damage forming factors includs seismic hazard assessment, design, construction and maintenance of building and facilities. Other one is formed by city planning characteristics and includes : density of constructions and population, area of soft soils, existence of liquefaction susceptible soils and etc. To all these factors has been given weight functions and interval values by groups. Methodical recomendations for loss asessment taking into account above mentioned factors were developed. It gives possibility to carry out preventive measures for protection of vulnerable territories, to differentiate cost assessment of each region in relation with territory peculiarity and damage value. Using developed method we have ranged cities by risk level. It has allowed to establish ratings of the general vulnerability of urban territories of cities and on their basis to make optimum decisions, oriented to loss mitigation and increase of safety of population. Besides the technique can be used by insurance companies for estimated zoning of territory, development of effective utilization schema of land resources, rational town-planning, an economic estimation of used territory for supply with information of the various works connected to an estimation of seismic hazard. Further improvement of technique of establishment of rating of cities by level of damage from earthquakes will allow to increase quality of construction, rationality of accommodation of buildings, will be an economic stimulator for increasing of seismic resistance of

  1. The periodicity of sleep duration – an infradian rhythm in spontaneous living

    Directory of Open Access Journals (Sweden)

    Wong SN

    2013-01-01

    Full Text Available Shi Ngar Wong, Mark Halaki, Chin Moi ChowDiscipline of Exercise and Sport Science, University of Sydney, Sydney, NSW, AustraliaAbstract: The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.Keywords: sleep regulation, homeostasis, habitual sleep, spontaneous living, healthy males

  2. Influence of WeChat on sleep quality among undergraduates in Chongqing, China: a cross-sectional study.

    Science.gov (United States)

    Xu, Xianglong; Lin, Qianyi; Zhang, Yan; Zhu, Runzhi; Sharma, Manoj; Zhao, Yong

    2016-01-01

    Previous studies showed that social media is associated with sleep quality. WeChat (a native social media in China) is very popular in China, especially among the youth. In the second quarter of 2016, Tencent's WeChat had 806 million monthly active users. The study sought to identify the influence of WeChat on the sleep quality among undergraduate students. A cross-sectional survey adopted a multi-stage stratified sampling survey to investigate undergraduates in Chongqing, China. Data were collected on 1979 eligible adults, aged 20.27 (SD: 1.26) years old, using Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality. Respondents aged 20.27 ± 1.26 years included 535 (27.0%) males, and 1311 (66.3%) reported as having poor sleep quality. Of the 1979 participants, 1320 (66.70%) were WeChat users. In multivariable analyses, gender, grade, nationality, living costs, the student leader, the only child, type of university, WeChat usage was associated with domains of PSQI among undergraduates ( p  students.

  3. Age-related influences of prior sleep on brain activation during verbal encoding

    Directory of Open Access Journals (Sweden)

    Michelle B Jonelis

    2012-04-01

    Full Text Available Disrupted sleep is more common in older adults (OA than younger adults (YA, often co-morbid with other conditions. How these sleep disturbances affect cognitive performance is an area of active study. We examined whether brain activation during verbal encoding correlates with sleep quantity and quality the night before testing in a group of healthy OA and YA. Twenty-seven OA (ages 59-82 and twenty-seven YA (ages 19-36 underwent one night of standard polysomnography. Twelve hours post-awakening, subjects performed a verbal encoding task while undergoing functional MRI. Analyses examined the group (OA vs. YA by prior sleep quantity (Total Sleep Time (TST or quality (Sleep Efficiency (SE interaction on cerebral activation, controlling for performance. Longer TST promoted higher levels of activation in the bilateral anterior parahippocampi in OA and lower activation levels in the left anterior parahippocampus in YA. Greater SE promoted higher activation levels in the left posterior parahippocampus and right inferior frontal gyrus in YA, but not in OA. The roles of these brain regions in verbal encoding suggest, in OA, longer sleep duration may facilitate functional compensation during cognitive challenges. By contrast, in YA, shorter sleep duration may necessitate functional compensation to maintain cognitive performance, similar to what is seen following acute sleep deprivation. Additionally, in YA, better sleep quality may improve semantic retrieval processes, thereby aiding encoding.

  4. Sleep deprivation influences some but not all processes of supervisory attention

    Science.gov (United States)

    Jennings, J. R.; Monk, T. H.; van der Molen, M. W.

    2003-01-01

    Does one night of sleep deprivation alter processes of supervisory attention in general or only a specific subset of such processes? Twenty college-aged volunteers, half female, performed a choice reaction time task. A cue indicated that compatible (e.g., right button, right-pointing arrow) or incompatible (e.g., left button, right-pointing arrow) responses were to be given to a stimulus that followed 50 or 500 ms later. The paradigm assessed response inhibition, task-shifting skill, and task strategy-processes inherent in supervisory attention. Performance, along with heart rate, was assessed for 12 hr following normal sleep or a night of complete sleep deprivation. Sleep deprivation altered neither preparation for task shifting nor response inhibition. The ability to use preparatory bias to speed performance did decrease with sleep deprivation. Sleep deprivation appears to selectively affect this supervisory attention process, which is perceived as an active effort to cope with a challenging task.

  5. Lipid solubility of sedative-hypnotic drugs influences hypothermic and hypnotic responses of long-sleep and short-sleep mice.

    Science.gov (United States)

    De Fiebre, N C; Marley, R J; Wehner, J M; Collins, A C

    1992-10-01

    The anesthetic potency of many agents, including alcohols, barbiturates and other sedative-hypnotic drugs, is influenced by lipid solubility. Previous studies from our laboratory, however, have demonstrated that genetic factors influence this relationship. We have reported that mouse lines selectively bred for differences in duration of ethanol-induced anesthesia, the long-sleep (LS) and short-sleep (SS) mice, differ in sleep-time response to water-soluble, but not lipid-soluble, sedative-hypnotic drugs. The studies described here sought to determine whether this same relationship exists for the hypothermic response produced by 17 sedative-hypnotic drugs in the LS and SS mice. Dose-response and time course relationships for hypothermic actions were determined and were compared with the dose-related anesthetic effects of the drugs. Hypothermic potencies increased along with lipid solubility for both the LS and SS mouse lines, but the rate of change differed for the two mouse lines. LS mice were more responsive to ethanol and other water-soluble drugs whereas the SS were more responsive to lipid-soluble drugs; significant correlations were obtained between lipid solubility (log P-octanol-water partition coefficient) and relative LS-SS responsiveness to both the hypothermic and hypnotic actions of the 17 test drugs. Thus, both hypnotic and hypothermic actions of sedative-hypnotic drugs are correlated with lipid solubility. Possible explanation for these correlations include greater LS central nervous system sensitivity to water-soluble drugs and LS-SS differences in distribution of lipid-soluble drugs.

  6. Sleep and cognition.

    Science.gov (United States)

    Deak, Maryann C; Stickgold, Robert

    2010-07-01

    Sleep is a complex physiologic state, the importance of which has long been recognized. Lack of sleep is detrimental to humans and animals. Over the past decade, an important link between sleep and cognitive processing has been established. Sleep plays an important role in consolidation of different types of memory and contributes to insightful, inferential thinking. While the mechanism by which memories are processed in sleep remains unknown, several experimental models have been proposed. This article explores the link between sleep and cognition by reviewing (1) the effects of sleep deprivation on cognition, (2) the influence of sleep on consolidation of declarative and non-declarative memory, and (3) some proposed models of how sleep facilitates memory consolidation in sleep. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Do Circadian Preferences Influence the Sleep Patterns of Night Shift Drivers?

    Science.gov (United States)

    Narciso, Fernanda V.; Esteves, Andrea M.; Oliveira e Silva, Luciana; Bittencourt, Lia R.A.; Silva, Rogerio S.; Pires, Maria Laura N.; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    Objective The objective of this study was to analyze the effect of individual circadian preferences of drivers with fixed night work schedules on sleep patterns. Subjects and Methods A total of 123 professional drivers, 32 indifferent preference drivers and 91 morning preference drivers of an intermunicipality and interstate bus transportation company were evaluated. All drivers underwent polysomnographic recordings after their shifts. Furthermore, they filled out a questionnaire that contained sociodemographic and health questions. The Horne and Östberg questionnaire was used to assess the subjects' morningness-eveningness preference. Results The mean age was 42.54 ± 6.98 years and 82 (66.66%) of the drivers had worked for ≥15 years. A significant effect on rapid eye movement (REM) was observed in the morning preference drivers. They showed an increased sleep latency and an REM sleep percentage of 5% of the total REM time. This reveals a significant effect on sleep architecture associated with work time. Conclusion The drivers reported that morning preference had a significant effect on their sleep pattern indicating less REM sleep and longer REM sleep latency in the morning preference group. Thus, it is important to evaluate interactions between individual aspects of health and other parameters, such as sleep quality and work organizational factors, to promote night shift workers' health and well-being. PMID:23988815

  8. The Influence of a Mandibular Advancement Plate on Polysomnography in Different Grades of Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Antti Raunio

    2015-03-01

    Full Text Available Objectives: The purpose of this study was to investigate the effect of a mandibular advancement device on different grades of obstructive sleep apnea using a relatively simple test for the apnea-hypopnea index to determine if a mandibular device will be effective. Material and Methods: A total of 68 patients with obstructive sleep apnea syndrome (OSAS including, 31 with mild, 23 with moderate and 14 with severe OSAS were treated with a mandibular advancement device (MAD and monitored with polysomnography. Results: 25 of the 31 mild, 15 of the 23 moderate and 2 of the 14 severe OSAS patients were cured of their OSAS if a post treatment apnea-hypopnea index of less than 5 is regarded as cured. The odds ratios for success with MAD therapy are 3 for women over men, 14.9 for mild obstructive sleep apnea, 5.42 for moderate obstructive sleep apnea if severe obstructive sleep apnea is assigned an odds ratio of 1. Conclusions: The use of the apnea-hypopnea index alone is useful in mild and moderate disease to predict the effectiveness of mandibular advancement device. Treatment with a mandibular advancement device is very effective in treating mild and moderate obstructive sleep apnea. Conservative treatment with a mandibular advancement device can be successful in less severe grades of sleep apnea and may be an alternative for non-surgical patients with severe obstructive sleep apnea intolerant of Continuous Positive Airway Pressure management.

  9. Do circadian preferences influence the sleep patterns of night shift drivers?

    Science.gov (United States)

    Narciso, Fernanda V; Esteves, Andrea M; Oliveira e Silva, Luciana; Bittencourt, Lia R A; Silva, Rogerio S; Pires, Maria Laura N; Tufik, Sergio; de Mello, Marco Tulio

    2013-01-01

    The objective of this study was to analyze the effect of individual circadian preferences of drivers with fixed night work schedules on sleep patterns. A total of 123 professional drivers, 32 indifferent preference drivers and 91 morning preference drivers of an intermunicipality and interstate bus transportation company were evaluated. All drivers underwent polysomnographic recordings after their shifts. Furthermore, they filled out a questionnaire that contained sociodemographic and health questions. The Horne and Östberg questionnaire was used to assess the subjects' morningness-eveningness preference. The mean age was 42.54 ± 6.98 years and 82 (66.66%) of the drivers had worked for ≥15 years. A significant effect on rapid eye movement (REM) was observed in the morning preference drivers. They showed an increased sleep latency and an REM sleep percentage of 5% of the total REM time. This reveals a significant effect on sleep architecture associated with work time. The drivers reported that morning preference had a significant effect on their sleep pattern indicating less REM sleep and longer REM sleep latency in the morning preference group. Thus, it is important to evaluate interactions between individual aspects of health and other parameters, such as sleep quality and work organizational factors, to promote night shift workers' health and well-being. © 2013 S. Karger AG, Basel.

  10. The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report

    Directory of Open Access Journals (Sweden)

    Aljohara S Almeneessier

    2017-01-01

    Conclusions: In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin.

  11. Choice of biomaterials—Do soft occlusal splints influence jaw-muscle activity during sleep? A preliminary report

    Science.gov (United States)

    Arima, Taro; Takeuchi, Tamiyo; Tomonaga, Akio; Yachida, Wataru; Ohata, Noboru; Svensson, Peter

    2012-12-01

    AimThe choice of biomaterials for occlusal splints may significantly influence biological outcome. In dentistry, hard acrylic occlusal splints (OS) have been shown to have a temporary and inhibitory effect on jaw-muscle activity, such as tooth clenching and grinding during sleep, i.e., sleep bruxism (SB). Traditionally, this inhibitory effect has been explained by changes in the intraoral condition rather than the specific effects of changes in occlusion. The aim of this preliminary study was to investigate the effect of another type of occlusal surface, such as a soft-material OS in addition to a hard-type OS in terms of changes in jaw-muscle activity during sleep. Materials and methodsSeven healthy subjects (mean ± SD, six men and one woman: 28.9 ± 2.7 year old), participated in this study. A soft-material OS (ethylene vinyl acetate copolymer) was fabricated for each subject and the subjects used the OS for five continuous nights. The EMG activity during sleep was compared to baseline (no OS). Furthermore, the EMG activity during the use of a hard-type OS (Michigan-type OS, acrylic resin), and hard-type OS combined with contingent electrical stimulation (CES) was compared to baseline values. Each session was separated by at least two weeks (washout). Jaw-muscle activity during sleep was recorded with single-channel ambulatory devices (GrindCare, MedoTech, Herlev, Denmark) in all sessions for five nights. ResultsJaw-muscle activity during sleep was 46.6 ± 29.8 EMG events/hour at baseline and significantly decreased during the hard-type OS (17.4 ± 10.5, P = 0.007) and the hard-type OS + CES (10.8 ± 7.1, P = 0.002), but not soft-material OS (36.3 ± 24.5, P = 0.055). Interestingly, the soft-material OS (coefficient of variance = 98.6 ± 35.3%) was associated with greater night-to-night variations than baseline (39.0 ± 11.8%) and the hard-type OS + CES (53.3 ± 13.7%, P < 0.013). ConclusionThe present pilot study in small sample showed that a soft

  12. Impact of sleep inertia on visual selective attention for rare targets and the influence of chronotype.

    Science.gov (United States)

    Ritchie, Hannah K; Burke, Tina M; Dear, Tristan B; Mchill, Andrew W; Axelsson, John; Wright, Kenneth P

    2017-10-01

    Sleep inertia is affected by circadian phase, with worse performance upon awakening from sleep during the biological night than biological day. Visual search/selective visual attention performance is known to be sensitive to sleep inertia and circadian phase. Individual differences exist in the circadian timing of habitual wake time, which may contribute to individual differences in sleep inertia. Because later chronotypes awaken at an earlier circadian phase, we hypothesized that later chronotypes would have worse visual search performance during sleep inertia than earlier chronotypes if awakened at habitual wake time. We analysed performance from 18 healthy participants [five females (22.1 ± 3.7 years; mean ± SD)] at ~1, 10, 20, 30, 40 and 60 min following electroencephalogram-verified awakening from an 8 h in-laboratory sleep opportunity. Cognitive throughput and reaction times of correct responses were impaired by sleep inertia and took ~10-30 min to improve after awakening. Regardless whether chronotype was defined by dim light melatonin onset or mid-sleep clock hour on free days, derived from the Munich ChronoType Questionnaire, the duration of sleep inertia for cognitive throughput and reaction times was longer for later chronotypes (n = 7) compared with earlier chronotypes (n = 7). Specifically, performance for earlier chronotypes showed significant improvement within ~10-20 min after awakening, whereas performance for later chronotypes took ~30 min or longer to show significant improvement (P inertia contributes to longer-lasting impairments in morning performance in later chronotypes. © 2017 European Sleep Research Society.

  13. Physiological stress response to loss of social influence and threats to masculinity.

    Science.gov (United States)

    Taylor, Catherine J

    2014-02-01

    Social influence is an important component of contemporary conceptualizations of masculinity in the U.S. Men who fail to achieve masculinity by maintaining social influence in the presence of other men may be at risk of stigmatization. As such, men should be especially likely to exhibit a stress response to loss of social influence in the presence of other men. This study assesses whether men who lose social influence exhibit more of a stress response than men who gain social influence, using data collected in a laboratory setting where participants were randomly assigned into four-person groups of varying sex compositions. The groups were videotaped working on two problem-solving tasks. Independent raters assessed change in social influence using a well-validated measure borrowed from experimental work in the Status Characteristics Theory tradition. Cortisol is used as a measure of stress response because it is known to increase in response to loss of social esteem. Results show that young men who lose social influence while working with other young men exhibit cortisol response. In contrast women do not exhibit cortisol response to loss of social influence, nor do men working with women. Results are consistent with the hypothesis that loss of social influence in men may be associated with a physiological stress response because maintaining social influence is very important to men while in the presence of other men. This physiological response to loss of social influence underscores the importance to men of achieving masculinity through gaining and maintaining social influence, and avoiding the stigma associated with the failure to do so. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Influence of Various Lifestyle and Psychosocial Factors on Sleep Disturbances among the College Students: A Cross-Sectional Study from an Urban Area of India

    Directory of Open Access Journals (Sweden)

    Yugantara R. Kadam

    2016-07-01

    Full Text Available Background: Sleep occupies nearly 1/3rd of our life and is essential for overall growth and stability. Sleep deprivation results weakening of physical functions, mental health problems like depression and lowering of productivity, thus resulting in loss to an individual and society. Aim and Objectives: Sleep is essential for physical and mental stability. Its deprivation lowers work productivity and results in mental problem like depression. Various lifestyle and psychosocial factors may have impact on the sleep. In the western countries the subject is amply explored; however studies on student from developing countries like India are limited. Our objective was to study the extent of sleep disturbance and associated factors among the graduating college students. Material and Methods: It is a cross-sectional study conducted in Arts, Commerce and Science graduating college students from an urban area. The sampling technique was cluster random sampling with the sample size of 890. A pretested, selfadministered questionnaire was used as a study tool. Statistical Analysis was done using percentages, chisquare test and bi-variate logistic regression. Results: The mean duration of sleep reported by the 900 study subjects was 7.3 hours (std. deviation 1 hour. Any sleep disturbance was reported by 826 (91.8% subjects; with day time sleepiness (77.5% and difficulty in falling asleep (65.4% being the commonest complaint. Sleep disturbance score was associated with exercise, outdoor games and tea / coffee intake. It was also associated with nocturnal use of mobiles and feeling depressed. Conclusion: Sleep disturbances were present in majority of college students with day time sleepiness as its commonest manifestation. Various lifestyle and psychosocial factors had impact on the sleep. Proper lifestyle modification and good family environment areimportant to avoid sleep disturbances among the college students.

  15. Influence of wavelength-dependent-loss on dispersive wave in nonlinear optical fibers.

    Science.gov (United States)

    Herrera, Rodrigo Acuna

    2012-11-01

    In this work, we study numerically the influence of wavelength-dependent loss on the generation of dispersive waves (DWs) in nonlinear fiber. This kind of loss can be obtained, for instance, by the acousto-optic effect in fiber optics. We show that this loss lowers DW frequency in an opposite way that the Raman effect does. Also, we see that the Raman effect does not change the DW frequency too much when wavelength-dependent loss is included. Finally, we show that the DW frequency is not practically affected by fiber length.

  16. Influence of chronotype and social zeitgebers on sleep/wake patterns

    Directory of Open Access Journals (Sweden)

    A.L. Korczak

    2008-10-01

    Full Text Available Inter-individual differences in the phase of the endogenous circadian rhythms have been established. Individuals with early circadian phase are called morning types; those with late circadian phase are evening types. The Horne and Östberg Morningness-Eveningness Questionnaire (MEQ is the most frequently used to assess individual chronotype. The distribution of MEQ scores is likely to be biased by several fact, ors, such as gender, age, genetic background, latitude, and social habits. The objective of the present study was to determine the effect of different social synchronizers on the sleep/wake cycle of persons with different chronotypes. Volunteers were selected from a total of 1232 UFPR undergraduate students who completed the MEQ. Thirty-two subjects completed the study, including 8 morning types, 8 evening types and 16 intermediate types. Sleep schedules were recorded by actigraphy for 1 week on two occasions: during the school term and during vacation. Sleep onset and offset times, sleep duration, and mid-sleep time for each chronotype group were compared by the Mann-Whitney U-test separately for school term and vacation. School term and vacation data were compared by the Wilcoxon matched-pair test. Morning types showed earlier sleep times and longer sleep duration compared with evening types (23:00 ± 44 and 508.9 ± 50.27 vs 01:08 ± 61.95 and 456.44 ± 59.08, for the weekdays during vacation. During vacation, the subjects showed later sleep times, except for the morning types, who did not exhibit differences for sleep onset times. The results support the idea that social schedules have an impact on the expression of circadian rhythmicity but this impact depends on the individual chronotype.

  17. The influence of sleep deprivation and obesity on DNA damage in female Zucker rats

    Directory of Open Access Journals (Sweden)

    Neuli M. Tenorio

    2013-01-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate overall genetic damage induced by total sleep deprivation in obese, female Zucker rats of differing ages. METHOD: Lean and obese Zucker rats at 3, 6, and 15 months old were randomly distributed into two groups for each age group: home-cage control and sleep-deprived (N = 5/group. The sleep-deprived groups were deprived sleep by gentle handling for 6 hours, whereas the home-cage control group was allowed to remain undisturbed in their home-cage. At the end of the sleep deprivation period, or after an equivalent amount of time for the home-cage control groups, the rats were brought to an adjacent room and decapitated. The blood, brain, and liver tissue were collected and stored individually to evaluate DNA damage. RESULTS: Significant genetic damage was observed only in 15-month-old rats. Genetic damage was present in the liver cells from sleep-deprived obese rats compared with lean rats in the same condition. Sleep deprivation was associated with genetic damage in brain cells regardless of obesity status. DNA damage was observed in the peripheral blood cells regardless of sleep condition or obesity status. CONCLUSION: Taken together, these results suggest that obesity was associated with genetic damage in liver cells, whereas sleep deprivation was associated with DNA damage in brain cells. These results also indicate that there is no synergistic effect of these noxious conditions on the overall level of genetic damage. In addition, the level of DNA damage was significantly higher in 15-month-old rats compared to younger rats.

  18. The influence of sleep deprivation and obesity on DNA damage in female Zucker rats.

    Science.gov (United States)

    Tenorio, Neuli M; Ribeiro, Daniel A; Alvarenga, Tathiana A; Fracalossi, Ana Carolina C; Carlin, Viviane; Hirotsu, Camila; Tufik, Sergio; Andersen, Monica L

    2013-01-01

    The aim of this study was to evaluate overall genetic damage induced by total sleep deprivation in obese, female Zucker rats of differing ages. Lean and obese Zucker rats at 3, 6, and 15 months old were randomly distributed into two groups for each age group: home-cage control and sleep-deprived (N = 5/group). The sleep-deprived groups were deprived sleep by gentle handling for 6 hours, whereas the home-cage control group was allowed to remain undisturbed in their home-cage. At the end of the sleep deprivation period, or after an equivalent amount of time for the home-cage control groups, the rats were brought to an adjacent room and decapitated. The blood, brain, and liver tissue were collected and stored individually to evaluate DNA damage. Significant genetic damage was observed only in 15-month-old rats. Genetic damage was present in the liver cells from sleep-deprived obese rats compared with lean rats in the same condition. Sleep deprivation was associated with genetic damage in brain cells regardless of obesity status. DNA damage was observed in the peripheral blood cells regardless of sleep condition or obesity status. Taken together, these results suggest that obesity was associated with genetic damage in liver cells, whereas sleep deprivation was associated with DNA damage in brain cells. These results also indicate that there is no synergistic effect of these noxious conditions on the overall level of genetic damage. In addition, the level of DNA damage was significantly higher in 15-month-old rats compared to younger rats.

  19. The influence of soil moisture transfer on building heat loss via the ground

    NARCIS (Netherlands)

    Janssen, H.M.; Carmeliet, J.; Hens, H.

    2004-01-01

    In this paper, the influence of soil moisture transfer on building heat loss via the ground is investigated by comparing fully coupled simulations with linear thermal simulations. The observed influences of coupling are (1) the larger amplitude of surface temperature, (2) the variation of thermal

  20. Genetic Dissociation of Daily Sleep and Sleep Following Thermogenetic Sleep Deprivation in Drosophila.

    Science.gov (United States)

    Dubowy, Christine; Moravcevic, Katarina; Yue, Zhifeng; Wan, Joy Y; Van Dongen, Hans P A; Sehgal, Amita

    2016-05-01

    Sleep rebound-the increase in sleep that follows sleep deprivation-is a hallmark of homeostatic sleep regulation that is conserved across the animal kingdom. However, both the mechanisms that underlie sleep rebound and its relationship to habitual daily sleep remain unclear. To address this, we developed an efficient thermogenetic method of inducing sleep deprivation in Drosophila that produces a substantial rebound, and applied the newly developed method to assess sleep rebound in a screen of 1,741 mutated lines. We used data generated by this screen to identify lines with reduced sleep rebound following thermogenetic sleep deprivation, and to probe the relationship between habitual sleep amount and sleep following thermogenetic sleep deprivation in Drosophila. To develop a thermogenetic method of sleep deprivation suitable for screening, we thermogenetically stimulated different populations of wake-promoting neurons labeled by Gal4 drivers. Sleep rebound following thermogenetically-induced wakefulness varies across the different sets of wake-promoting neurons that were stimulated, from very little to quite substantial. Thermogenetic activation of neurons marked by the c584-Gal4 driver produces both strong sleep loss and a substantial rebound that is more consistent within genotypes than rebound following mechanical or caffeine-induced sleep deprivation. We therefore used this driver to induce sleep deprivation in a screen of 1,741 mutagenized lines generated by the Drosophila Gene Disruption Project. Flies were subjected to 9 h of sleep deprivation during the dark period and released from sleep deprivation 3 h before lights-on. Recovery was measured over the 15 h following sleep deprivation. Following identification of lines with reduced sleep rebound, we characterized baseline sleep and sleep depth before and after sleep deprivation for these hits. We identified two lines that consistently exhibit a blunted increase in the duration and depth of sleep after

  1. Changes in attention to an emotional task after sleep deprivation: neurophysiological and behavioral findings.

    Science.gov (United States)

    Alfarra, Ramey; Fins, Ana I; Chayo, Isaac; Tartar, Jaime L

    2015-01-01

    While sleep loss is shown to have widespread effects on cognitive processes, little is known about the impact of sleep loss on emotion processes. In order to expand on previous behavioral and physiological findings on how sleep loss influences emotion processing, we administered positive, negative, and neutral affective visual stimuli to individuals after one night of sleep deprivation while simultaneously acquiring EEG event related potential (ERP) data and recording affective behavioral responses. We compared these responses to a baseline testing session. We specifically looked at the late positive potential (LPP) component of the visual ERP as an established sensitive measure of attention to emotionally-charged visual stimuli. Our results show that after sleep deprivation, the LPP no longer discriminates between emotional and non-emotional pictures; after sleep deprivation the LPP amplitude was of similar amplitude for neutral, positive, and negative pictures. This effect was driven by an increase in the LPP to neutral pictures. Our behavioral measures show that, relative to baseline testing, emotional pictures are rated as less emotional following sleep deprivation with a concomitant reduction in emotional picture-induced anxiety. We did not observe any change in cortisol concentrations after sleep deprivation before or after emotional picture exposure, suggesting that the observed changes in emotion processing are independent of potential stress effects of sleep deprivation. Combined, our findings suggest that sleep loss interferes with proper allocation of attention resources during an emotional task. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Sleep-wake cycle of adolescents in Côte d'Ivoire: influence of age, gender, religion and occupation.

    Science.gov (United States)

    Borchers, Claudia; Randler, Christoph

    2012-12-01

    The human sleep-wake cycle is characterized by significant individual differences. Those differences in the sleep-wake cycle are partially heritable but are also influenced by environmental factors like the light/dark cycle or social habits. In this study we analyse for the first time the sleep-wake rhythm of adolescent pupils and working adolescents in a less industrialised country in West Africa near the equator. The aim of this study was to explore the sleep wake cycle in this geographical region, using Côte d'Ivoire as an example. Data collection took place between 2nd of March and 10th of June 2009. 588 adolescents (338 girls, 250 boys) between 10 and 15 years (mean ± SD: 12.72 ± 1.63) participated in this study. We collected data on the religion of the participants (Christian (N = 159), Muslim (N = 352), other/no religion (N = 77)) and their occupation. Participants were either pupils attending school (N = 336) or adolescents that were already working (N = 252) and not attending school. The interviewer filled in the questionnaire. We found significant effects of age (p gender (p religion (p < 0.001) and region (p < 0.001). The midpoint of sleep was on average 1:26 (SD: 00:30) on weekdays and 1:37 (SD: 00:42) on weekend days. There are significant differences between weekdays and weekend days, but these were only small. Sleep duration suggests that adolescents in Côte d'Ivoire may gain sufficient sleep during week and weekend days, and thus, may live more in accordance with their own biological clock than adolescents in the northern hemisphere. In contrast, the data can be interpreted that adolescents live in a permanent 'jetlag'. Factors may be the more continuous light/dark cycle in the tropics, low amount of ambient light and less electricity.

  3. Damage of Inner Ear Sensory Hair Cells via Mitochondrial Loss in a Murine Model of Sleep Apnea With Chronic Intermittent Hypoxia.

    Science.gov (United States)

    Seo, Young Joon; Ju, Hyun Mi; Lee, Sun Hee; Kwak, Sang Hyun; Kang, Min Jung; Yoon, Joo-Heon; Kim, Chang-Hoon; Cho, Hyung-Ju

    2017-09-01

    Investigating the exact pathophysiology of obstructive sleep apnea syndrome (OSAS)-induced hearing loss is critical. We sought to verify the hypothesis that a correlation exists between mitochondrial dysfunction in inner ear hair cells and the auditory dysfunction induced by chronic intermittent hypoxia (CIH) in a murine model of sleep apnea. C57BL/6J adult male mice were randomized to 4 weeks of CIH (n = 12) or normoxia (Sham) (n = 12). Hearing threshold was determined by auditory brainstem response. The activity of mitochondria was compared between CIH and Sham mice. Histological assessment and transmission electron microscopy were performed for assessing morphologic changes in mitochondria. The number of mtDNA copies as well as the levels of PGC1-α, Tfam, and VDAC (voltage-dependent anion channel) were determined in the hair cells of CIH mice. We observed that hearing ability in CIH mice was impaired and hair-cell mitochondria in CIH mice were fewer compared to that in Sham and also displayed an aberrant morphology. The mRNA levels of PGC-1α and Tfam were higher in the CIH group than in the Sham group. Moreover, the expression of VDAC was increased in the tectorial membrane, the basilar membrane, and especially in the inner hair cells of CIH mice. This study using CIH mice as a model for OSAS provides evidence of an association between OSAS and auditory function alteration, as well as of mitochondria being part of the pathophysiology of hearing impairment. Further investigation is required to determine whether mitochondria could serve as a valid target for preventive or therapeutic purposes. © 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.

  4. The Sleeping Cerebellum.

    Science.gov (United States)

    Canto, Cathrin B; Onuki, Yoshiyuki; Bruinsma, Bastiaan; van der Werf, Ysbrand D; De Zeeuw, Chris I

    2017-05-01

    We sleep almost one-third of our lives and sleep plays an important role in critical brain functions like memory formation and consolidation. The role of sleep in cerebellar processing, however, constitutes an enigma in the field of neuroscience; we know little about cerebellar sleep-physiology, cerebro-cerebellar interactions during sleep, or the contributions of sleep to cerebellum-dependent memory consolidation. Likewise, we do not understand why cerebellar malfunction can lead to changes in the sleep-wake cycle and sleep disorders. In this review, we evaluate how sleep and cerebellar processing may influence one another and highlight which scientific routes and technical approaches could be taken to uncover the mechanisms underlying these interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Influence of sleep disturbance, fatigue, vitality on oral health and academic performance in indian dental students.

    Science.gov (United States)

    Asawa, Kailash; Sen, Nandini; Bhat, Nagesh; Tak, Mridula; Sultane, Pratibha; Mandal, Aritra

    2017-01-01

    Oral health and academic performance are important contributing factors for a student's professional life. Countless factors affect both, among which sleep, vitality and fatigue are less explored areas that also have a strong impact. The objective of the study was to assess the association of sleep disturbances, fatigue and vitality with self reported oral health status, oral hygiene habits and academic performance of dental students of Udaipur. A descriptive cross-sectional study was conducted among undergraduate and postgraduate dental students of Udaipur. Self-administered structured questionnaire was used to assess the psychological factors, vitality, sleep quality, fatigue, self reported oral health status, habits and academic performance. Analysis of variance and stepwise multiple linear regression were utilized for statistical analysis with 95% confidence level and 5% level of significance. Of the 230 participants, 180 (78.3%) were undergraduates and 50 (21.7%) were postgraduates. Among them, females showed higher scores in disturbed sleep index (2.69±2.14) as compared to males (2.45±1.91). Respondents who had "Poor" dental health, scored more in disturbed sleep index (3.15±1.64) and fatigue scale (20.00±4.88). Subjects who flossed "everyday", were found to have good sleep and more energy (p=0.01) and those who assessed themselves as excellent students scored more in the Vitality Scale (p=0.01) and less in the Sleep index (p=0.01). The present study confirms that disturbed sleep, aliveness and fatigue, all are interlinked with each other and are imperative factors having the potential to alter the oral health status, habits and academics of dental students.

  6. Predictive Modeling of Physician-Patient Dynamics That Influence Sleep Medication Prescriptions and Clinical Decision-Making

    Science.gov (United States)

    Beam, Andrew L.; Kartoun, Uri; Pai, Jennifer K.; Chatterjee, Arnaub K.; Fitzgerald, Timothy P.; Shaw, Stanley Y.; Kohane, Isaac S.

    2017-02-01

    Insomnia remains under-diagnosed and poorly treated despite its high economic and social costs. Though previous work has examined how patient characteristics affect sleep medication prescriptions, the role of physician characteristics that influence this clinical decision remains unclear. We sought to understand patient and physician factors that influence sleep medication prescribing patterns by analyzing Electronic Medical Records (EMRs) including the narrative clinical notes as well as codified data. Zolpidem and trazodone were the most widely prescribed initial sleep medication in a cohort of 1,105 patients. Some providers showed a historical preference for one medication, which was highly predictive of their future prescribing behavior. Using a predictive model (AUC = 0.77), physician preference largely determined which medication a patient received (OR = 3.13 p = 3 × 10-37). In addition to the dominant effect of empirically determined physician preference, discussion of depression in a patient’s note was found to have a statistically significant association with receiving a prescription for trazodone (OR = 1.38, p = 0.04). EMR data can yield insights into physician prescribing behavior based on real-world physician-patient interactions.

  7. Acute Sleep Loss Induces Tissue-Specific Epigenetic and Transcriptional Alterations to Circadian Clock Genes in Men.

    Science.gov (United States)

    Cedernaes, Jonathan; Osler, Megan E; Voisin, Sarah; Broman, Jan-Erik; Vogel, Heike; Dickson, Suzanne L; Zierath, Juleen R; Schiöth, Helgi B; Benedict, Christian

    2015-09-01

    Shift workers are at increased risk of metabolic morbidities. Clock genes are known to regulate metabolic processes in peripheral tissues, eg, glucose oxidation. This study aimed to investigate how clock genes are affected at the epigenetic and transcriptional level in peripheral human tissues following acute total sleep deprivation (TSD), mimicking shift work with extended wakefulness. In a randomized, two-period, two-condition, crossover clinical study, 15 healthy men underwent two experimental sessions: x sleep (2230-0700 h) and overnight wakefulness. On the subsequent morning, serum cortisol was measured, followed by skeletal muscle and subcutaneous adipose tissue biopsies for DNA methylation and gene expression analyses of core clock genes (BMAL1, CLOCK, CRY1, PER1). Finally, baseline and 2-h post-oral glucose load plasma glucose concentrations were determined. In adipose tissue, acute sleep deprivation vs sleep increased methylation in the promoter of CRY1 (+4%; P = .026) and in two promoter-interacting enhancer regions of PER1 (+15%; P = .036; +9%; P = .026). In skeletal muscle, TSD vs sleep decreased gene expression of BMAL1 (-18%; P = .033) and CRY1 (-22%; P = .047). Concentrations of serum cortisol, which can reset peripheral tissue clocks, were decreased (2449 ± 932 vs 3178 ± 723 nmol/L; P = .039), whereas postprandial plasma glucose concentrations were elevated after TSD (7.77 ± 1.63 vs 6.59 ± 1.32 mmol/L; P = .011). Our findings demonstrate that a single night of wakefulness can alter the epigenetic and transcriptional profile of core circadian clock genes in key metabolic tissues. Tissue-specific clock alterations could explain why shift work may disrupt metabolic integrity as observed herein.

  8. Sex differences in paradoxical sleep: influences of estrus cycle and ovariectomy.

    Science.gov (United States)

    Fang, J; Fishbein, W

    1996-09-23

    Previously, we reported that paradoxical sleep (PS) is sexually dimorphic in mice and rats. Since some early studies indicate that PS is suppressed during proestrus night, it is important to know whether the estrus cycle and accompanying circulating ovarian hormones could explain the sexual dimorphism of PS. To examine this, sleep patterns of male rats were compared with those of normal cycling female rats and ovariectomized females in a 12:12 h light/dark cycle. Slow wave sleep and total sleep time are indistinguishable between the males, cycling females and ovariectomized females. However, normal males display significantly more PS than cycling females during both daytime and nighttime (average of all estrus stages). On the other hand, while ovariectomy has no visible effect on daytime sleep--the sexual dimorphism of PS is unchanged by ovariectomy--during nighttime, ovariectomy produces a selective increase of PS, eliminating the sex difference during the night. In sum, normal cycling females show no change in daytime sleep patterns across the estrus cycle, but have significantly less PS during proestrus nights than during metestrus and diestrus nights. The results indicate that the sex difference in nighttime PS is due to the suppression of PS by ovarian hormones during proestrus and, to a less extent, estrus nights. The sex difference in daytime PS, on the other hand, appears to be independent of circulating ovarian hormones.

  9. The influence of sleep duration and sleep-related symptoms on baseline neurocognitive performance among male and female high school athletes.

    Science.gov (United States)

    Sufrinko, Alicia; Johnson, Eric W; Henry, Luke C

    2016-05-01

    Typically, the effects of sleep duration on cognition are examined in isolation. This study examined the effects of restricted sleep and related symptoms on neurocognitive performance. Baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and postconcussion symptom scale (PCSS) were administered to athletes (N = 7,150) ages 14-17 (M = 15.26, SD = 1.09) prior to sport participation. Three groups of athletes were derived from total sleep duration: sleep restriction (≤5 hours), typical sleep (5.5-8.5 hours), and optimal sleep (≥9 hours). A MANCOVA (age and sex as covariates) was conducted to examine differences across ImPACT/PCSS. Follow-up MANOVA compared ImPACT/PCSS performance among symptomatic (e.g., trouble falling asleep, sleeping less than usual) adolescents from the sleep restriction group (n = 78) with asymptomatic optimal sleepers (n = 99). A dose-response effect of sleep duration on ImPACT performance and PCSS was replicated (Wilk's λ = .98, F2,7145 = 17.25, p sleep restricted adolescents (n = 78) had poorer neurocognitive performance: verbal memory, F = 11.60, p = .001, visual memory, F = 6.57, p = .01, visual motor speed, F = 6.19, p = .01, and reaction time (RT), F = 5.21, p = .02, compared to demographically matched controls (n = 99). Girls in the sleep problem group performed worse on RT (p = .024). Examining the combination of sleep-related symptoms and reduced sleep duration effectively identified adolescents at risk for poor neurocognitive performance than sleep duration alone. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Factors influencing maternal decision-making for the infant sleep environment in families at higher risk of SIDS: a qualitative study.

    Science.gov (United States)

    Pease, Anna; Ingram, Jenny; Blair, Peter S; Fleming, Peter J

    2017-01-01

    Qualitative interviews with mothers of babies at higher risk of sudden infant death syndrome (SIDS) were carried out to understand their views and decision-making process on the infant sleep environment and safe sleep messages. Twenty semi-structured interviews were conducted between February and November 2014 in deprived areas of Bristol, UK. Mothers were asked about their decision-making for the infant sleep environment and safe sleep messages including infant sleep position, co-sleeping, smoking, dummy use, feeding and disrupted routines. The interviews were transcribed, coded and thematic analysis carried out. Participants were invited based on an algorithm developed in a previous SIDS case control study that identified an increased risk of SIDS from four demographic characteristics: young maternal age, smoking during pregnancy, three or more children, and a measure of deprivation. The presence of three, or more characteristics led to being invited to take part in the qualitative study. Factors influencing mothers' adherence to the safe sleep messages included previous experience and the credibility of the advice given. They described disrupted routines that led to risky scenarios with a belief that occasional risks were acceptable. Where circumstances made following the advice more difficult they found alternative strategies to reduce the risk, including the use of movement monitors, regular checking and a belief that lighter maternal sleep in the presence of a baby was protective. Safer sleep messages should be tailored to fit with the lived realities of mothers, especially those at higher risk. The traditional list of 'do's' and 'don'ts' was not well accepted by this group. Interventions that seek to influence this higher-risk group should acknowledge mothers' own protective instincts and consider their beliefs and understanding behind the safer sleep messages if they are to be effective and encourage this group to change.

  11. Sleep and the endocrine system.

    Science.gov (United States)

    Morgan, Dionne; Tsai, Sheila C

    2015-07-01

    In this article, the effect of sleep and sleep disorders on endocrine function and the influence of endocrine abnormalities on sleep are discussed. Sleep disruption and its associated endocrine consequences in the critically ill patient are also reviewed. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Influence of the sleep on health, behavior and school performance of students of 2nd and 3rd cycle of basic school

    OpenAIRE

    Oliveira, Olinda; Anastácio, Zélia

    2013-01-01

    Resumo publicado em Mayo 2013 na Edição Especial Congreso I da revista científica internacional Atención Primaria indexada nas bases de dados Medline, Embase, Scopus y Science Citation Index Expanded Introduction: Sleep is a vital function, playing a central role in health and quality of life. Objectives: To determine the quantity and quality of sleep of the students according to their residence milieu, gender and school grade; identify external factors that influence sleep; inquire the in...

  13. The influence of environmental factors on sleep quality in hospitalized medical patients

    Directory of Open Access Journals (Sweden)

    Milena eBano

    2014-12-01

    Full Text Available Introduction. Sleep-wake disturbances are common in hospitalised patients but few studies have assessed them systematically. The aim of the present study was to assess sleep quality in a group of medical inpatients, in relation to environmental factors, and the switch to daylight saving time. Methods. Between March and April 2013, 132 consecutive inpatients were screened and 99 (76±11 yrs; hospitalization: 8±7 days enrolled. They slept in double or quadruple rooms, facing South/South-East, and were qualified as sleeping near/far from the window. They underwent daily sleep assessment by standard questionnaires/diaries. Illuminance was measured by a luxmeter at each patient’s eye-level, four times per day. Noise was measured at the same times by a phonometer. Information was recorded on room lighting, position of the rolling shutters and number/type of extra people in the room. Results. Compliance with sleep-wake assessment was poor, with a range of completion of 2-59%, depending on the questionnaires. Reported sleep quality was sufficient and sleep timing dictated by hospital routine; 33% of the patients reported one/more sleepless nights. Illuminance was generally low, and rolling shutters half way down for most of the 24 hours. Patients who slept near the window were exposed to more light in the morning (i.e. 222±72 vs. 174±85 lux, p<0.05 before the switch; 198±72 vs.141±137 lux, p<0.01 after the switch and tended to slept better (7.3±1.8 vs. 5.8±2.4 on a 1-10 scale, before the switch, p<0.05; 7.7±2.3 vs. 6.6±1.8, n.s. after the switch. Noise levels were higher than recommended for care units but substantially comparable across times/room types. No significant differences were observed in sleep parameters before/after the switch. Conclusions. Medical wards appear to be noisy environments, in which limited attention is paid to light/dark hygiene. An association was observed between sleep quality and bed position/light exposure, which

  14. Sleep, noise and health: Review

    Directory of Open Access Journals (Sweden)

    Mia Zaharna

    2010-01-01

    Full Text Available Sleep is a physiologic recuperative state that may be negatively affected by factors such as psychosocial and work stress as well as external stimuli like noise. Chronic sleep loss is a common problem in today′s society, and it may have significant health repercussions such as cognitive impairment, and depressed mood, and negative effects on cardiovascular, endocrine, and immune function. This article reviews the definition of disturbed sleep versus sleep deprivation as well as the effects of noise on sleep. We review the various health effects of chronic partial sleep loss with a focus on the neuroendocrine/hormonal, cardiovascular, and mental health repercussions.

  15. Sleep duration, depression, and oxytocinergic genotype influence prepulse inhibition of the startle reflex in postpartum women.

    Science.gov (United States)

    Comasco, Erika; Gulinello, Maria; Hellgren, Charlotte; Skalkidou, Alkistis; Sylven, Sara; Sundström-Poromaa, Inger

    2016-04-01

    The postpartum period is characterized by a post-withdrawal hormonal status, sleep deprivation, and susceptibility to affective disorders. Postpartum mothering involves automatic and attentional processes to screen out new external as well as internal stimuli. The present study investigated sensorimotor gating in relation to sleep duration, depression, as well as catecholaminergic and oxytocinergic genotypes in postpartum women. Prepulse inhibition (PPI) of the startle reflex and startle reactivity were assessed two months postpartum in 141 healthy and 29 depressed women. The catechol-O-methyltransferase (COMT) Val158Met, and oxytocin receptor (OXTR) rs237885 and rs53576 polymorphisms were genotyped, and data on sleep duration were collected. Short sleep duration (less than four hours in the preceding night) and postpartum depression were independently associated with lower PPI. Also, women with postpartum depression had higher startle reactivity in comparison with controls. The OXTR rs237885 genotype was related to PPI in an allele dose-dependent mode, with T/T healthy postpartum women carriers displaying the lowest PPI. Reduced sensorimotor gating was associated with sleep deprivation and depressive symptoms during the postpartum period. Individual neurophysiological vulnerability might be mediated by oxytocinergic genotype which relates to bonding and stress response. These findings implicate the putative relevance of lower PPI of the startle response as an objective physiological correlate of liability to postpartum depression. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

  16. Influence of Yoga and Ayurveda on self-rated sleep in a geriatric population.

    Science.gov (United States)

    Manjunath, N K; Telles, Shirley

    2005-05-01

    Sleep in older persons is characterized by decreased ability to stay asleep, resulting in fragmented sleep and reduced daytime alertness. Pharmacological treatment of insomnia in older persons is associated with hazardous side effects. Hence, the present study was designed to compare the effects of Yoga and Ayurveda on the self rated sleep in a geriatric population. Of the 120 residents from a home for the aged, 69 were stratified based on age (five year intervals) and randomly allocated to three groups i.e., Yoga (physical postures, relaxation techniques, voluntarily regulated breathing and lectures on yoga philosophy), Ayurveda (a herbal preparation), and Wait-list control (no intervention). The groups were evaluated for self-assessment of sleep over a one week period at baseline, and after three and six months of the respective interventions. The Yoga group showed a significant decrease in the time taken to fall asleep (approximate group average decrease: 10 min, P<0.05), an increase in the total number of hours slept (approximate group average increase: 60 min, P< 0.05) and in the feeling of being rested in the morning based on a rating scale (P<0.05) after six months. The other groups showed no significant change. Yoga practice improved different aspects of sleep in a geriatric population.

  17. Total dietary sugar consumption does not influence sleep or behaviour in Australian children.

    Science.gov (United States)

    Watson, Emily J; Coates, Alison M; Banks, Siobhan; Kohler, Mark

    2018-06-01

    This study aimed to compare sugar intake in Australian children with current guidelines and determine if total sugar consumption as a percentage of energy (sugar %E) exacerbates the relationship between sleep and behaviour. A sample of 287 children aged 8-12 years (boys 48.8%, age: 10.7 ± 1.3 years), and their parents/guardians completed a battery of questionnaires. Children completed a food frequency questionnaire, and parents completed demographic, sleep, and behaviour questionnaires. Average sugar intake was 134.9 ± 71.7 g per day (sugar %E 26.0 ± 7.0%), and only 55 (19%) participants did not exceed the recommended sugar intake limit. Correlations and logistical regressions indicated that sugar %E was not associated with sleep or behavioural domains (r range = -0.07-0.08; p range = .173-.979) nor contributed to the prediction of sleep behaviour problems (p range = .16-.80). Whilst a high proportion of children consumed above the recommended amount of daily total sugar, total sugar consumption was not related to behavioural or sleep problems, nor affected the relationship between these variables.

  18. On The Snubber Influence To The Switching And Conduction Losses In A Converter Using Switched Capacitor

    Directory of Open Access Journals (Sweden)

    Viorel DUGAN

    2002-12-01

    Full Text Available The paper deals to design and to compute the snubber parameters influence on the switching and conduction losses of the transistors (IGBT used as bidirectional switches in a converter with switched capacitor. The converter was modelled with difference equations, and the transistors during turn-on and turn-off processes were simulated by dynamically varying resistance models. The energy loss per switching, commutation time, the variation of the transistor voltage etc. and the influence of snubber parameters in each of these cases are shown in the context of a converter used as a 50Hz reactive power controller unit

  19. The influence of losses in the core of an inductor on characteristics of the boost converter

    International Nuclear Information System (INIS)

    Górecki, Krzysztof; Detka, Kalina

    2016-01-01

    In the paper the influence of core losses on characteristics of the boost converter is considered. In calculations, the average electrothermal models of the diode-transistor switch and of the inductor are used. The applied electrothermal models and the obtained results of calculations are presented. The selected results of calculations are compared with the results of measurements. The influence of such factors as converter load resistance and frequency of the control signal and lossiness of the core on characteristics of the considered converter and the loss of energy in the inductor are discussed

  20. The Inevitability of Sleep: Using Manet's Last Paintings to Envision a Pedagogy of Loss and Mourning

    Science.gov (United States)

    Otto, Stacy

    2013-01-01

    In this article, the author offers Manet's last paintings as metaphors for a bygone, psychically healthy conception of loss and mourning, what is called the pre-Freudian, Victorian notion of loss (Otto 2008), which contrasts with the post-Freudian, Modern notion of loss and mourning (Otto 2008). Otto argues this liminal, transitional moment…

  1. Sleep disorders and work performance: findings from the 2008 National Sleep Foundation Sleep in America poll.

    Science.gov (United States)

    Swanson, Leslie M; Arnedt, J Todd; Rosekind, Mark R; Belenky, Gregory; Balkin, Thomas J; Drake, Christopher

    2011-09-01

    Chronic sleep deprivation is common among workers, and has been associated with negative work outcomes, including absenteeism and occupational accidents. The objective of the present study is to characterize reciprocal relationships between sleep and work. Specifically, we examined how sleep impacts work performance and how work affects sleep in individuals not at-risk for a sleep disorder; assessed work performance outcomes for individuals at-risk for sleep disorders, including insomnia, obstructive sleep apnea (OSA) and restless legs syndrome (RLS); and characterized work performance impairments in shift workers (SW) at-risk for shift work sleep disorders relative to SW and day workers. One-thousand Americans who work 30 h per week or more were asked questions about employment, work performance and sleep in the National Sleep Foundation's 2008 Sleep in America telephone poll. Long work hours were associated with shorter sleep times, and shorter sleep times were associated with more work impairments. Thirty-seven percent of respondents were classified as at-risk for any sleep disorder. These individuals had more negative work outcomes as compared with those not at-risk for a sleep disorder. Presenteeism was a significant problem for individuals with insomnia symptoms, OSA and RLS as compared with respondents not at-risk. These results suggest that long work hours may contribute to chronic sleep loss, which may in turn result in work impairment. Risk for sleep disorders substantially increases the likelihood of negative work outcomes, including occupational accidents, absenteeism and presenteeism. © 2010 European Sleep Research Society.

  2. Sleeping site selection by agile gibbons: the influence of tree stability, fruit availability and predation risk.

    Science.gov (United States)

    Cheyne, Susan M; Höing, Andrea; Rinear, John; Sheeran, Lori K

    2012-01-01

    Primates spend a significant proportion of their lives at sleeping sites: the selection of a secure and stable sleeping tree can be crucial for individual survival and fitness. We measured key characteristics of all tree species in which agile gibbons slept, including exposure of the tree crown, root system, height, species and presence of food. Gibbons most frequently slept in Dipterocarpaceae and Fabaceae trees and preferentially chose trees taller than average, slept above the mean canopy height and showed a preference for liana-free trees. These choices could reflect avoidance of competition with other frugivores, but we argue these choices reflect gibbons prioritizing avoidance of predation. The results highlight that gibbons are actively selecting and rejecting sleeping trees based on several characteristics. The importance of the presence of large trees for food is noted and provides insight into gibbon antipredatory behaviour. Copyright © 2013 S. Karger AG, Basel.

  3. Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

    KAUST Repository

    Tay-Wo-Chong, Luis

    2015-11-16

    The present paper argues that the prediction of turbulent premixed flames under non-adiabatic conditions can be improved by considering the combined effects of strain and heat loss on reaction rates. The effect of strain in the presence of heat loss on the consumption speed of laminar premixed flames was quantified by calculations of asymmetric counterflow configurations (“fresh-to-burnt”) with detailed chemistry. Heat losses were introduced by setting the temperature of the incoming stream of products on the “burnt” side to values below those corresponding to adiabatic conditions. The consumption speed decreased in a roughly exponential manner with increasing strain rate, and this tendency became more pronounced in the presence of heat losses. An empirical relation in terms of Markstein number, Karlovitz Number and a non-dimensional heat loss parameter was proposed for the combined influence of strain and heat losses on the consumption speed. Combining this empirical relation with a presumed probability density function for strain in turbulent flows, an attenuation factor that accounts for the effect of strain and heat loss on the reaction rate in turbulent flows was deduced and implemented into a turbulent combustion model. URANS simulations of a premixed swirl burner were carried out and validated against flow field and OH chemiluminescence measurements. Introducing the effects of strain and heat loss into the combustion model, the flame topology observed experimentally was correctly reproduced, with good agreement between experiment and simulation for flow field and flame length.

  4. The Influence of Gestational Age on the Loss of Maternal Measles ...

    African Journals Online (AJOL)

    Background: Maternal measles antibodies (MMA) are actively transferred in mother-infant pairs during third trimester of pregnancy. Gestational age (GA) affects the levels of MMA such that longer GA may result in infants starting out with high levels of MMA. Objective: To determine the influence of GA on the loss of MMA in ...

  5. Myopic Loss Aversion: Demystifying the Key Factors Influencing Decision Problem Framing

    Science.gov (United States)

    Hardin, Andrew M.; Looney, Clayton Arlen

    2012-01-01

    Advancement of myopic loss aversion theory has been hamstrung by conflicting results, methodological inconsistencies, and a piecemeal approach toward understanding the key factors influencing decision problem framing. A series of controlled experiments provides a more holistic view of the variables promoting myopia. Extending the information…

  6. Sleep in athletes and the effects of Ramadan.

    Science.gov (United States)

    Roky, Rachida; Herrera, Christopher Paul; Ahmed, Qanta

    2012-01-01

    Sleep is now considered as a new frontier in performance enhancement. This article presents background content on sleep function, sleep needs and methods of sleep investigation along with data on the potential effects of Ramadan fasting on sleep in normal individuals and athletes. Accumulated sleep loss has negative impacts on cognitive function, mood, daytime sleepiness and performance. Sleep studies in athletes fasting during Ramadan are very rare. Most of them have demonstrated that during this month, sleep duration decreased and sleep timing shifted. But the direct relation between sleep changes and performance during Ramadan is not yet elucidated. Objective sleep patterns can be investigated using polysomnography, actigraphy, and standardised questionnaires and recorded in daily journals or sleep logs. The available data on sleep indicate that team doctors and coaches should consider planning sleep schedule and napping; implementing educational programmes focusing on the need for healthy sleep; and consider routine screening for sleep loss in athletes of all age groups and genders.

  7. Influence of fatigue, stress, muscle soreness and sleep on perceived exertion during submaximal effort.

    Science.gov (United States)

    Haddad, Monoem; Chaouachi, Anis; Wong, Del P; Castagna, Carlo; Hambli, Mourad; Hue, Olivier; Chamari, Karim

    2013-07-02

    The aim of this study was to assess the effects of the Hooper's Index variations (i.e., self-ratings of fatigue, stress, delayed onset muscle soreness (DOMS), and sleep) on rating of perceived exertion during a 10 min submaximal exercise training session (RPE-10 min) and then check the stability and the internal consistency of RPE-10 min. Seventeen junior soccer players took part in this study. The individual Hooper's indices taken before each training session were correlated with RPE-10 min during a constant intensity and duration effort (10 min) using Pearson product moment correlation. Intraclass correlation (ICC) was used to assess the internal consistency of the RPE-10 min. All individual correlations between RPE-10 min and quality of sleep and quantity of fatigue, stress, and DOMS were non-significant (p>0.05). No significant correlations were resulted between RPE-10 min and Hooper's Index in all athletes. The ICC of RPE-10 min was 0.77 thus demonstrating internal consistency. The results of the present study demonstrated the objectivity and utility of RPE as a psychological tool for monitoring training during traditional soccer training. Therefore, the results of the present study suggest that fatigue, stress, DOMS and sleep are not major contributors of perceived exertion during traditional soccer training without excessive training loads. It seems that psychobiological factors other than fatigue, stress, DOMS and sleep may have mediated the 10 min exercise perceptual intensity. © 2013.

  8. Influence of Day Length and Physical Activity on Sleep Patterns in Older Icelandic Men and Women

    DEFF Research Database (Denmark)

    Brychta, Robert J; Arnardóttir, Nanna Ýr; Jóhannsson, Erlingur

    2016-01-01

    Study Objectives: To identify cross-sectional and seasonal patterns of sleep and physical activity (PA) in community-dwelling, older Icelandic adults using accelerometers. Methods: A seven-day free-living protocol of 244 (110 female) adults aged 79.7 +/- 4.9 years was conducted as part of a larger...

  9. Do Mandibular Advancement Devices Influence Patients' Snoring and Obstructive Sleep Apnea?

    DEFF Research Database (Denmark)

    Marcussen, Lillian; Henriksen, Jan Erik; Thygesen, Torben

    2015-01-01

    Student's t test and the Wilcoxon signed rank test, and mixed-model analyses were performed adjusting for sleep apnea severity, type 2 diabetes, body mass index, gender, and age. RESULTS: A total of 44 patients (31 men and 13 women, age 50 ± 13 years, body mass index 31 ± 5.6 kg/m(2)) completed the trial...

  10. Influence of experimental esophageal acidification on sleep bruxism: a randomized trial.

    Science.gov (United States)

    Ohmure, H; Oikawa, K; Kanematsu, K; Saito, Y; Yamamoto, T; Nagahama, H; Tsubouchi, H; Miyawaki, S

    2011-05-01

    The aim of this cross-over, randomized, single-blinded trial was to examine whether intra-esophageal acidification induces sleep bruxism (SB). Polysomnography with electromyogram (EMG) of masseter muscle, audio-video recording, and esophageal pH monitoring were performed in a sleep laboratory. Twelve healthy adult males without SB participated. Intra-esophageal infusions of 5-mL acidic solution (0.1 N HCl) or saline were administered. The frequencies of EMG bursts, rhythmic masticatory muscle activity (RMMA) episodes, grinding noise, and the RMMA/microarousal ratio were significantly higher in the 20-minute period after acidic infusion than after saline infusion. RMMA episodes including SB were induced by esophageal acidification. This trial is registered with the UMIN Clinical Trials Registry, UMIN000002923. ASDA, American Sleep Disorders Association; EMG, electromyogram; GER, gastroesophageal reflux; LES, lower esophageal sphincter; NREM, non-rapid eye movement; REM, rapid eye movement; RMMA, rhythmic masticatory muscle activity; SB, sleep bruxism; SD, standard deviation; UES, upper esophageal sphincter.

  11. Partial Sleep Deprivation Attenuates the Positive Affective System: Effects Across Multiple Measurement Modalities.

    Science.gov (United States)

    Finan, Patrick H; Quartana, Phillip J; Remeniuk, Bethany; Garland, Eric L; Rhudy, Jamie L; Hand, Matthew; Irwin, Michael R; Smith, Michael T

    2017-01-01

    Ample behavioral and neurobiological evidence links sleep and affective functioning. Recent self-report evidence suggests that the affective problems associated with sleep loss may be stronger for positive versus negative affective state and that those effects may be mediated by changes in electroencepholographically measured slow wave sleep (SWS). In the present study, we extend those preliminary findings using multiple measures of affective functioning. In a within-subject randomized crossover experiment, we tested the effects of one night of sleep continuity disruption via forced awakenings (FA) compared to one night of uninterrupted sleep (US) on three measures of positive and negative affective functioning: self-reported affective state, affective pain modulation, and affect-biased attention. The study was set in an inpatient clinical research suite. Healthy, good sleeping adults (N = 45) were included. Results indicated that a single night of sleep continuity disruption attenuated positive affective state via FA-induced reductions in SWS. Additionally, sleep continuity disruption attenuated the inhibition of pain by positive affect as well as attention bias to positive affective stimuli. Negative affective state, negative affective pain facilitation, nor negative attention bias were altered by sleep continuity disruption. The present findings, observed across multiple measures of affective function, suggest that sleep continuity disruption has a stronger influence on the positive affective system relative to the negative affective affective system. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  12. The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

    Directory of Open Access Journals (Sweden)

    Hehua Zhu

    2015-01-01

    Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

  13. Phase of Spontaneous Slow Oscillations during Sleep Influences Memory-Related Processing of Auditory Cues.

    Science.gov (United States)

    Batterink, Laura J; Creery, Jessica D; Paller, Ken A

    2016-01-27

    Slow oscillations during slow-wave sleep (SWS) may facilitate memory consolidation by regulating interactions between hippocampal and cortical networks. Slow oscillations appear as high-amplitude, synchronized EEG activity, corresponding to upstates of neuronal depolarization and downstates of hyperpolarization. Memory reactivations occur spontaneously during SWS, and can also be induced by presenting learning-related cues associated with a prior learning episode during sleep. This technique, targeted memory reactivation (TMR), selectively enhances memory consolidation. Given that memory reactivation is thought to occur preferentially during the slow-oscillation upstate, we hypothesized that TMR stimulation effects would depend on the phase of the slow oscillation. Participants learned arbitrary spatial locations for objects that were each paired with a characteristic sound (eg, cat-meow). Then, during SWS periods of an afternoon nap, one-half of the sounds were presented at low intensity. When object location memory was subsequently tested, recall accuracy was significantly better for those objects cued during sleep. We report here for the first time that this memory benefit was predicted by slow-wave phase at the time of stimulation. For cued objects, location memories were categorized according to amount of forgetting from pre- to post-nap. Conditions of high versus low forgetting corresponded to stimulation timing at different slow-oscillation phases, suggesting that learning-related stimuli were more likely to be processed and trigger memory reactivation when they occurred at the optimal phase of a slow oscillation. These findings provide insight into mechanisms of memory reactivation during sleep, supporting the idea that reactivation is most likely during cortical upstates. Slow-wave sleep (SWS) is characterized by synchronized neural activity alternating between active upstates and quiet downstates. The slow-oscillation upstates are thought to provide a

  14. Mask Ventilation during Induction of General Anesthesia: Influences of Obstructive Sleep Apnea.

    Science.gov (United States)

    Sato, Shin; Hasegawa, Makoto; Okuyama, Megumi; Okazaki, Junko; Kitamura, Yuji; Sato, Yumi; Ishikawa, Teruhiko; Sato, Yasunori; Isono, Shiroh

    2017-01-01

    Depending on upper airway patency during anesthesia induction, tidal volume achieved by mask ventilation may vary. In 80 adult patients undergoing general anesthesia, the authors tested a hypothesis that tidal volume during mask ventilation is smaller in patients with sleep-disordered breathing priorly defined as apnea hypopnea index greater than 5 per hour. One-hand mask ventilation with a constant ventilator setting (pressure-controlled ventilation) was started 20 s after injection of rocuronium and maintained for 1 min during anesthesia induction. Mask ventilation efficiency was assessed by the breath number needed to initially exceed 5 ml/kg ideal body weight of expiratory tidal volume (primary outcome) and tidal volumes (secondary outcomes) during initial 15 breaths (UMIN000012494). Tidal volume progressively increased by more than 70% in 1 min and did not differ between sleep-disordered breathing (n = 42) and non-sleep-disordered breathing (n = 38) patients. In post hoc subgroup analyses, the primary outcome breath number (mean [95% CI], 5.7 [4.1 to 7.3] vs. 1.7 [0.2 to 3.2] breath; P = 0.001) and mean tidal volume (6.5 [4.6 to 8.3] vs. 9.6 [7.7 to 11.4] ml/kg ideal body weight; P = 0.032) were significantly smaller in 20 sleep-disordered breathing patients with higher apnea hypopnea index (median [25th to 75th percentile]: 21.7 [17.6 to 31] per hour) than in 20 non-sleep disordered breathing subjects with lower apnea hypopnea index (1.0 [0.3 to 1.5] per hour). Obesity and occurrence of expiratory flow limitation during one-hand mask ventilation independently explained the reduction of efficiency of mask ventilation, while the use of two hands effectively normalized inefficient mask ventilation during one-hand mask ventilation. One-hand mask ventilation is difficult in patients with obesity and severe sleep-disordered breathing particularly when expiratory flow limitation occurs during mask ventilation.

  15. Sleep disturbances in Parkinsonism.

    Science.gov (United States)

    Askenasy, J J M

    2003-02-01

    The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment

  16. The influence of use-related, environmental, and managerial factors on soil loss from recreational trails

    Science.gov (United States)

    Olive, Nathaniel D.; Marion, Jeffrey L.

    2009-01-01

    Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding “fall-line” alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes.This research also sought to develop a more efficient Variable Cross-Sectional Area method for assessing soil loss on trails. This method permitted incorporation of CSA measures in a representative sampling scheme applied to a large (24%) sample of the park's 526 km trail system. The variety of soil loss measures derived from the Variable CSA method, including extrapolated trail-wide soil loss estimates, permit an objective quantification of soil erosion on recreational trails and roads. Such data support relational analyses to increase understanding of trail degradation, and long

  17. The influence of use-related, environmental, and managerial factors on soil loss from recreational trails.

    Science.gov (United States)

    Olive, Nathaniel D; Marion, Jeffrey L

    2009-03-01

    Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding "fall-line" alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes. This research also sought to develop a more efficient Variable Cross-Sectional Area method for assessing soil loss on trails. This method permitted incorporation of CSA measures in a representative sampling scheme applied to a large (24%) sample of the park's 526 km trail system. The variety of soil loss measures derived from the Variable CSA method, including extrapolated trail-wide soil loss estimates, permit an objective quantification of soil erosion on recreational trails and roads. Such data support relational analyses to increase understanding of trail degradation, and long-term monitoring of

  18. The Neuroprotective Aspects of Sleep.

    Science.gov (United States)

    Eugene, Andy R; Masiak, Jolanta

    2015-03-01

    Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of sleep is a serious concern that people need to be aware of. When one sleeps, the brain reorganizes and recharges itself, and removes toxic waste byproducts which have accumulated throughout the day. This evidence demonstrates that sleeping can clear the brain and help maintain its normal functioning. Multiple studies have been done to determine the effects of total sleep deprivation; more recently some have been conducted to show the effects of sleep restriction, which is a much more common occurrence, have the same effects as total sleep deprivation. Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment. As a background for this paper we have reviewed literature and research of sleep phases, effects of sleep deprivation, and the glymphatic system of the brain and its restorative effect during the sleep cycle.

  19. Influence of serial electrical stimulations of perifornical and posterior hypothalamic orexin-containing neurons on regulation of sleep homeostasis and sleep-wakefulness cycle recovery from experimental comatose state and anesthesia-induced deep sleep.

    Science.gov (United States)

    Chijavadze, E; Chkhartishvili, E; Babilodze, M; Maglakelidze, N; Nachkebia, N

    2013-11-01

    The work was aimed for the ascertainment of following question - whether Orexin-containing neurons of dorsal and lateral hypothalamic, and brain Orexinergic system in general, are those cellular targets which can speed up recovery of disturbed sleep homeostasis and accelerate restoration of sleep-wakefulness cycle phases during some pathological conditions - experimental comatose state and/or deep anesthesia-induced sleep. Study was carried out on white rats. Modeling of experimental comatose state was made by midbrain cytotoxic lesions at intra-collicular level.Animals were under artificial respiration and special care. Different doses of Sodium Ethaminal were used for deep anesthesia. 30 min after comatose state and/or deep anesthesia induced sleep serial electrical stimulations of posterior and/or perifornical hypothalamus were started. Stimulation period lasted for 1 hour with the 5 min intervals between subsequent stimulations applied by turn to the left and right side hypothalamic parts.EEG registration of cortical and hippocampal electrical activity was started immediately after experimental comatose state and deep anesthesia induced sleep and continued continuously during 72 hour. According to obtained new evidences, serial electrical stimulations of posterior and perifornical hypothalamic Orexin-containing neurons significantly accelerate recovery of sleep homeostasis, disturbed because of comatose state and/or deep anesthesia induced sleep. Speed up recovery of sleep homeostasis was manifested in acceleration of coming out from comatose state and deep anesthesia induced sleep and significant early restoration of sleep-wakefulness cycle behavioral states.

  20. Sleep and sleep disorders in Don Quixote.

    Science.gov (United States)

    Iranzo, Alex; Santamaria, Joan; de Riquer, Martín

    2004-01-01

    In Don Quijote de la Mancha, Miguel de Cervantes presents Don Quixote as an amazing character of the 17th century who suffers from delusions and illusions, believing himself to be a medieval knight errant. Besides this neuropsychiatric condition, Cervantes included masterful descriptions of several sleep disorders such as insomnia, sleep deprivation, disruptive loud snoring and rapid eye movement sleep behaviour disorder. In addition, he described the occurrence of physiological, vivid dreams and habitual, post-prandial sleepiness--the siesta. Cervantes' concept of sleep as a passive state where all cerebral activities are almost absent is in conflict with his description of abnormal behaviours during sleep and vivid, fantastic dreams. His concept of sleep was shared by his contemporary, Shakespeare, and could have been influenced by the reading of the classical Spanish book of psychiatry Examen de Ingenios (1575).

  1. Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching.

    Science.gov (United States)

    Spinato, Sergio; Galindo-Moreno, Pablo; Bernardello, Fabio; Zaffe, Davide

    This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss.

  2. Sleep stages, memory and learning.

    Science.gov (United States)

    Dotto, L

    1996-04-15

    Learning and memory can be impaired by sleep loss during specific vulnerable "windows" for several days after new tasks have been learned. Different types of tasks are differentially vulnerable to the loss of different stages of sleep. Memory required to perform cognitive procedural tasks is affected by the loss of rapid-eye-movement (REM) sleep on the first night after learning occurs and again on the third night after learning. REM-sleep deprivation on the second night after learning does not produce memory deficits. Declarative memory, which is used for the recall of specific facts, is not similarly affected by REM-sleep loss. The learning of procedural motor tasks, including those required in many sports, is impaired by the loss of stage 2 sleep, which occurs primarily in the early hours of the morning. These findings have implications for the academic and athletic performance of students and for anyone whose work involves ongoing learning and demands high standards of performance.

  3. Influence of end-joint methods on magnetization loss in striated helical conductors

    International Nuclear Information System (INIS)

    Kim, Woo Seok; Kim, Yung Il; Choi, Kyeong Dal; Lee, Ji Kwang

    2013-01-01

    To reduce the magnetization loss of a coated conductor, the striation and the transposition have to be accomplished for magnetic decoupling. The loss reduction effect in incomplete as well as complete striated YBCO CCs was reported in previous research. At the case of the incomplete striated sample, the end region of the sample is non-striated. So, it is not jointed with each other. In power applications, the joint is needed because current leads must be connected with HTS coils. In this research, the influence of end-joint methods with copper and superconducting joint on magnetization loss in striated YBCO CC and spiral winding samples are presented and compared with non-striated measured result.

  4. Sleep Loss Reduces the DNA-Binding of BMAL1, CLOCK, and NPAS2 to Specific Clock Genes in the Mouse Cerebral Cortex

    OpenAIRE

    Mongrain, Valerie; La Spada, Francesco; Curie, Thomas; Franken, Paul

    2011-01-01

    We have previously demonstrated that clock genes contribute to the homeostatic aspect of sleep regulation. Indeed, mutations in some clock genes modify the markers of sleep homeostasis and an increase in homeostatic sleep drive alters clock gene expression in the forebrain. Here, we investigate a possible mechanism by which sleep deprivation (SD) could alter clock gene expression by quantifying DNA-binding of the core-clock transcription factors CLOCK, NPAS2, and BMAL1 to the cis-regulatory s...

  5. Influence of ionic strength on the viscosities and water loss of bentonite suspensions containing polymers

    Directory of Open Access Journals (Sweden)

    Luciana Viana Amorim

    2007-03-01

    Full Text Available A study was made of the influence of ionic strength (S on the apparent (AV and plastic (PV viscosities and water loss (WL of sodium bentonite suspension with polymers. Na-bentonite was dispersed in water (4.86% w/w of different ionic strengths (S = 0.0, 0.015, 0.030 and 0.045 M followed by the addition of polymer. Three polymer samples were studied, i.e., low viscosity carboxymethyl cellulose (CMC BV, polyanionic cellulose (PAC, and partially hydrolyzed polyacrylamide (HPAM. The results indicated that the presence of salts and increased salinity greatly influence the apparent and plastic viscosities and water loss of bentonite suspensions with polymer.

  6. Sleep Disorders

    Science.gov (United States)

    ... the day, even if you have had enough sleep? You might have a sleep disorder. The most common kinds are Insomnia - a hard time falling or staying asleep Sleep apnea - breathing interruptions during sleep Restless legs syndrome - ...

  7. Sleep Problems

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... 101 KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  8. Influence of skin optical losses on configurational photoisomerization of bilirubin during phototherapy

    International Nuclear Information System (INIS)

    Pratesi, R.; Cecchi, G.

    1984-01-01

    Kubelka-Munk theory of radiation transfer in turbid media is applied to determine the influence of skin optical losses on the efficiency of phototherapy of neonatal hyperbilirubinemia. By using a multilayer model of the skin and a rate equation analysis of bilirubin photoisomerization, the photon absorption rates of birilubin and of its configurational photoisomers and, in turn, the photoequilibrium concentrations and rise time are calculated for spectrally Gaussian light sources and fluorescent lamps used in phototherapy

  9. Loss of Substantia Nigra Hyperintensity at 3.0-T MR Imaging in Idiopathic REM Sleep Behavior Disorder: Comparison with 123I-FP-CIT SPECT.

    Science.gov (United States)

    Bae, Yun Jung; Kim, Jong-Min; Kim, Kyeong Joon; Kim, Eunhee; Park, Hyun Soo; Kang, Seo Young; Yoon, In-Young; Lee, Jee-Young; Jeon, Beomseok; Kim, Sang Eun

    2018-04-01

    Purpose To examine whether the loss of nigral hyperintensity (NH) on 3.0-T susceptibility-weighted (SW) magnetic resonance (MR) images can help identify high synucleinopathy risk in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). Materials and Methods Between March 2014 and April 2015, 18 consecutively recruited patients with iRBD were evaluated with 3.0-T SW imaging and iodine 123-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane ( 123 I-FP-CIT) single photon emission computed tomography and compared with 18 healthy subjects and 18 patients with Parkinson disease (PD). Two readers blinded to clinical diagnosis independently assessed the images. 123 I-FP-CIT uptake ratios were compared by using the Kruskal-Wallis test, and intra- and interobserver agreements were assessed with the Cohen κ. The synucleinopathy conversion according to NH status was evaluated in patients with iRBD after follow-up. Results NH was intact in seven patients with iRBD and lost in 11. The 123 I-FP-CIT uptake ratios were comparable between those with intact NH (mean, 3.22 ± 0.47) and healthy subjects (mean, 3.37 ± 0.47) (P = .495). The 123 I-FP-CIT uptake ratios in the 11 patients with iRBD and NH loss (mean, 2.48 ± 0.44) were significantly lower than those in healthy subjects (mean, 3.37 ± 0.47; P 0.9). Five patients with iRBD and NH loss developed symptoms of parkinsonism or dementia 18 months after neuroimaging. Conclusion NH loss at 3.0-T SW imaging may be a promising marker for short-term synucleinopathy risk in iRBD. © RSNA, 2017 Online supplemental material is available for this article.

  10. Neuronal and molecular mechanisms of sleep homeostasis.

    Science.gov (United States)

    Donlea, Jeffrey M

    2017-12-01

    Sleep is necessary for survival, and prolonged waking causes a homeostatic increase in the need for recovery sleep. Homeostasis is a core component of sleep regulation and has been tightly conserved across evolution from invertebrates to man. Homeostatic sleep regulation was first identified among insects in cockroaches several decades ago, but the characterization of sleep rebound in Drosophila melanogaster opened the use of insect model species to understand homeostatic functions and regulation of sleep. This review describes circuits in two neuropil structures, the central complex and mushroom bodies, that influence sleep homeostasis and neuromodulatory systems that influence the accrual of homeostatic sleep need. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Sleep Issues and Sundowning

    Science.gov (United States)

    ... Caregiving Middle-Stage Caregiving Late-Stage Caregiving Behaviors Aggression & Anger Anxiety & Agitation Depression Hallucinations Memory Loss & Confusion Repetition Sleep Issues & Sundowning Suspicion & Delusions Wandering Abuse Start Here What You Need to Know Online ...

  12. I sleep, because we sleep: a synthesis on the role of culture in sleep behavior research.

    Science.gov (United States)

    Airhihenbuwa, C O; Iwelunmor, J I; Ezepue, C J; Williams, N J; Jean-Louis, G

    2016-02-01

    The aim of this study was to synthesize the literature on the cultural aspects of sleep and their relevance to behavioral sleep research. A narrative synthesis of the existing literature on sleep was conducted with a focus on its biological, sociological, political, and anthropological aspects. This synthesis was guided by the PEN-3 cultural model, developed by the primary author. The findings highlight the cross-cultural contexts within which people sleep and the role of varied sleeping arrangements in influencing sleep behavior and perspectives. Furthermore, the contexts in which sleep occurs, coupled with the influence of the family, and the positive aspects of sleep helped illustrate why cultural aspects of sleep are vital for a broader understanding of sleep. The authors conclude by highlighting the need to integrate studies on the biological, sociological, and political aspects of sleep. Our examination of the literature strongly suggests that careful assessment of epidemiological and clinical sleep data should consider the cultural aspects of sleep as well as the context in which sleep occurs, the role of the family, and positive aspects of sleep. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Experimental study on the influence of the rotating cylinder and circling pistons on churning losses in axial piston pumps

    OpenAIRE

    Zhang, Junhui; Li, Ying; Xu, Bing; Pan, Min; Lv, Fei

    2017-01-01

    Pressure and performance requirements of axial piston pumps and the proportion of churning losses in axial piston pumps increase significantly with increasing speed. To investigate the primary distribution of churning losses in axial piston pumps at various ranges of speed, a test rig was set up in which other friction losses can be eliminated, thus making it possible to investigate the net churning losses in an axial piston pump. The influence of the rotating cylinder block and pistons on ch...

  14. Aging worsens the effects of sleep deprivation on postural control.

    Science.gov (United States)

    Robillard, Rébecca; Prince, François; Filipini, Daniel; Carrier, Julie

    2011-01-01

    Falls increase with age and cause significant injuries in the elderly. This study aimed to determine whether age modulates the interactions between sleep deprivation and postural control and to evaluate how attention influences these interactions in the elderly. Fifteen young (24±2.7 y.o.) and 15 older adults (64±3.2 y.o.) stood still on a force plate after a night of sleep and after total sleep deprivation. Center of pressure range and velocity were measured with eyes open and with eyes closed while participants performed an interference task, a control task, and no cognitive task. Sleep deprivation increased the antero-posterior range of center of pressure in both age groups and center of pressure speed in older participants only. In elderly participants, the destabilizing effects of sleep deprivation were more pronounced with eyes closed. The interference task did not alter postural control beyond the destabilization induced by sleep loss in older subjects. It was concluded that sleep loss has greater destabilizing effects on postural control in older than in younger participants, and may therefore increase the risk of falls in the elderly.

  15. Aging Worsens the Effects of Sleep Deprivation on Postural Control

    Science.gov (United States)

    Robillard, Rébecca; Prince, François; Filipini, Daniel; Carrier, Julie

    2011-01-01

    Falls increase with age and cause significant injuries in the elderly. This study aimed to determine whether age modulates the interactions between sleep deprivation and postural control and to evaluate how attention influences these interactions in the elderly. Fifteen young (24±2.7 y.o.) and 15 older adults (64±3.2 y.o.) stood still on a force plate after a night of sleep and after total sleep deprivation. Center of pressure range and velocity were measured with eyes open and with eyes closed while participants performed an interference task, a control task, and no cognitive task. Sleep deprivation increased the antero-posterior range of center of pressure in both age groups and center of pressure speed in older participants only. In elderly participants, the destabilizing effects of sleep deprivation were more pronounced with eyes closed. The interference task did not alter postural control beyond the destabilization induced by sleep loss in older subjects. It was concluded that sleep loss has greater destabilizing effects on postural control in older than in younger participants, and may therefore increase the risk of falls in the elderly. PMID:22163330

  16. Pancreatic cancerrelated cachexia: influence on metabolism and correlation to weight loss and pulmonary function

    International Nuclear Information System (INIS)

    Bachmann, Jeannine; Ketterer, Knut; Marsch, Christiane; Fechtner, Kerstin; Krakowski-Roosen, Holger; Büchler, Markus W; Friess, Helmut; Martignoni, Marc E

    2009-01-01

    Dramatic weight loss is an often underestimated symptom in pancreatic cancer patients. Cachexia- defined as an unintended loss of stable weight exceeding 10% – is present in up to 80% of patients with cancer of the upper gastrointestinal tract, and has a significant influence on survival. The aim of the study was to show the multiple systemic effects of cachexia in pancreatic cancer patients, in terms of resection rate, effects on pulmonary function, amount of fat and muscle tissue, as well as changes in laboratory parameters. In patients with pancreatic cancer, clinical appearance was documented, including the amount of weight loss. Laboratory parameters and lung-function tests were evaluated, and the thickness of muscle and fat tissue was measured with computed tomography scans. Statistical analysis, including multivariate analysis, was performed using SPSS software. Survival curves were calculated using Kaplan-Meier analysis and the log-rank test. To test for significant differences between the examined groups we used Student's t-test and the Mann-Whitney U test. Significance was defined as p < 0.05. Of 198 patients with a ductal adenocarcinoma of the pancreas, 70% were suffering from weight loss when they presented for operation, and in 40% weight loss exceeded 10% of the stable weight. In patients with cachexia, metastases were diagnosed significantly more often (47% vs. 24%, P < 0.001), leading to a significantly reduced resection rate in these patients. Patients with cachexia had significantly reduced fat tissue amounts. Hence, dramatic weight loss in a patient with pancreatic cancer may be a hint of a more progressed or more aggressive tumour. Pancreatic cancer patients with cachexia had a higher rate of more progressed tumour stages and a worse nutritional status. Furthermore, patients with cachexia had an impaired lung function and a reduction in fat tissue. Patients with pancreatic cancer and cachexia had significantly reduced survival. If weight

  17. Pancreatic cancerrelated cachexia: influence on metabolism and correlation to weight loss and pulmonary function

    Energy Technology Data Exchange (ETDEWEB)

    Bachmann, Jeannine; Ketterer, Knut [Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich (Germany); Marsch, Christiane [Department of General Surgery, University of Heidelberg, Heidelberg (Germany); Fechtner, Kerstin [Department of Radiology, University of Heidelberg, Heidelberg (Germany); Krakowski-Roosen, Holger [German Cancer Research Center, Heidelberg (Germany); Büchler, Markus W [Department of General Surgery, University of Heidelberg, Heidelberg (Germany); Friess, Helmut; Martignoni, Marc E [Department of Surgery, Klinikum rechts der Isar, Technische Universität München, Munich (Germany)

    2009-07-28

    Dramatic weight loss is an often underestimated symptom in pancreatic cancer patients. Cachexia- defined as an unintended loss of stable weight exceeding 10% – is present in up to 80% of patients with cancer of the upper gastrointestinal tract, and has a significant influence on survival. The aim of the study was to show the multiple systemic effects of cachexia in pancreatic cancer patients, in terms of resection rate, effects on pulmonary function, amount of fat and muscle tissue, as well as changes in laboratory parameters. In patients with pancreatic cancer, clinical appearance was documented, including the amount of weight loss. Laboratory parameters and lung-function tests were evaluated, and the thickness of muscle and fat tissue was measured with computed tomography scans. Statistical analysis, including multivariate analysis, was performed using SPSS software. Survival curves were calculated using Kaplan-Meier analysis and the log-rank test. To test for significant differences between the examined groups we used Student's t-test and the Mann-Whitney U test. Significance was defined as p < 0.05. Of 198 patients with a ductal adenocarcinoma of the pancreas, 70% were suffering from weight loss when they presented for operation, and in 40% weight loss exceeded 10% of the stable weight. In patients with cachexia, metastases were diagnosed significantly more often (47% vs. 24%, P < 0.001), leading to a significantly reduced resection rate in these patients. Patients with cachexia had significantly reduced fat tissue amounts. Hence, dramatic weight loss in a patient with pancreatic cancer may be a hint of a more progressed or more aggressive tumour. Pancreatic cancer patients with cachexia had a higher rate of more progressed tumour stages and a worse nutritional status. Furthermore, patients with cachexia had an impaired lung function and a reduction in fat tissue. Patients with pancreatic cancer and cachexia had significantly reduced survival. If weight loss

  18. The influence of dew point during annealing on the power loss of electrical steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Broddefalk, Arvid [Development and Market Research, Cogent Power Ltd., P.O. Box 201, SE-735 23 Surahammar (Sweden)], E-mail: arvid.broddefalk@sura.se; Jenkins, Keith [Development and Market Research, Cogent Power Ltd., P.O. Box 201, SE-735 23 Surahammar (Sweden); Silk, Nick [Corus RD and T, Swinden Technology Centre, Moorgate Rotherham S60 3AR (United Kingdom); Lindenmo, Magnus [Development and Market Research, Cogent Power Ltd., P.O. Box 201, SE-735 23 Surahammar (Sweden)

    2008-10-15

    Decarburization is a necessary part of the processing of electrical steels if their carbon content is above a certain level. The process is usually carried out in a wet hydrogen-nitrogen atmosphere. Having a high dew point has a negative influence on the power loss, though. This is due to oxidation of the steel, which hinders domain wall motion near the surface. In this study, an increase of the power loss was only observed at a fairly high dew point (>20 deg. C). It was also only at these high dew points where a subsurface oxide layer was observed. The surfaces of samples with and without this layer were etched in steps. The magnetic properties of the etched samples corresponded well with the expected behavior based on GDOES profiles of the samples.

  19. The influence of dew point during annealing on the power loss of electrical steel sheets

    Science.gov (United States)

    Broddefalk, Arvid; Jenkins, Keith; Silk, Nick; Lindenmo, Magnus

    Decarburization is a necessary part of the processing of electrical steels if their carbon content is above a certain level. The process is usually carried out in a wet hydrogen-nitrogen atmosphere. Having a high dew point has a negative influence on the power loss, though. This is due to oxidation of the steel, which hinders domain wall motion near the surface. In this study, an increase of the power loss was only observed at a fairly high dew point (>20 °C). It was also only at these high dew points where a subsurface oxide layer was observed. The surfaces of samples with and without this layer were etched in steps. The magnetic properties of the etched samples corresponded well with the expected behavior based on GDOES profiles of the samples.

  20. Regional contextual influences on short sleep duration: a 50 universities population-based multilevel study in China.

    Science.gov (United States)

    Yang, Tingzhong; Peng, Sihui; Barnett, Ross; Zhang, Chichen

    2018-01-01

    Ecological models have emphasized that short sleep duration (SSD) is influenced by both individual and environmental variables. However, few studies have considered the latter. The present study explores the influence of urban and regional contextual factors, net of individual characteristics, on the prevalence of SSD among university students in China. Participants were 11,954 students, who were identified through a multistage survey sampling process conducted in 50 universities. Individual data were obtained through a self-administered questionnaire, and contextual variables were retrieved from a national database. Multilevel logistic regression models were used to examine urban and regional variations in high and moderate levels of SSD. Overall the prevalence of high SSD (individual- and city-level covariates. Students attending high-level universities also recorded the highest levels of SSD. Of the individual characteristcs, only mother's occupation and student mental health status were related to SSD. The results of this study add important insights about the role of contextual factors affecting SSD among young adults and indicate the need to take into account both past, as well as present, environmental influences to control SSD.

  1. The influence of the lateral pharyngeal wall anatomy on snoring and sleep apnoea.

    Science.gov (United States)

    Korhan, Ibrahim; Gode, Sercan; Midilli, Rasit; Basoglu, Ozen Kacmaz

    2015-02-01

    To elucidate the variations of the lateral pharyngeal wall anatomy on physical examination and to assess the clinical importance of the examination of the lateral pharyngeal wall on the presence and severity of obstructive sleep apnoea syndrome. The cross-sectional study was conducted at Ege University Medical School, Izmir, Turkey, between May 2010 and April 2011. The patients were divided into four equal groups: Group 1--snoring without apnoea (age 20-40); Group 2--snoring without apnoea (age 40-60); Group 3--apnoea-hypopnoea index 30/hr. Calibrated oropharynx pictures were taken. Distance between palatoglossal and palatopharyngeal arches, height of palatoglossal and palatopharyngeal arches, uvula width, uvula length and distance between tonsils were measured. SPSS 17 was used for statistical analysis. Of the 80 patients in the study, 44 (55%) were men. Mean distance between palatopharyngeal and palatoglossal arches were 1.55 ± 0.34 cm and 2.70 ± 0.43 cm respectively. Mean height of palatopharyngeal and palatoglossal arches were 0.60 ± 0.21 cm and 1.37 ± 0.36 cm respectively (p > 0.05). Mean uvula width and uvula length were 0.80 ± 0.12cm and 1.25 ± 0.27 cm respectively (p > 0.05). Mean distance between tonsils was 2.24 ± 0.56 cm (p > 0.05). Distance between palatopharyngeal arches was significantly different between groups 3 and 4 (p < 0.05). Palatopharyngeal arch anatomy was found to be significantly associated with obstructive sleep apnoea syndrome severity, especially in patients with normal or small tonsil size. Patients with the palatopharyngeal arches, which narrow the oropharyngeal inlet more than the tonsils, should further be investigated with polysomnography.

  2. 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.

  3. Sleep as an Occupational Need.

    Science.gov (United States)

    Tester, Nicole J; Foss, Joanne Jackson

    In the same way the human body requires food, hydration, and oxygen, it also requires sleep. Even among healthy people, the amount and quality of sleep substantially influence health and quality of life because sleep helps regulate physiological functioning. Given the impact of sleep on participation, the American Occupational Therapy Association reclassified sleep from an activity of daily living to an occupational domain. Poor sleep is a frequent medical complaint, especially among populations with neurological impairment. Occupational therapy practitioners should consider routinely screening for factors affecting their clients' sleep. By addressing such factors, as well as related routines and habits, practitioners can enhance the effectiveness of rehabilitation, promote health and well-being, and increase engagement and life quality. Practitioners should acknowledge the importance of sleep in practice, and the study of sleep should be prioritized by researchers in the field to meet client needs and establish evidence for interventions. Copyright © 2018 by the American Occupational Therapy Association, Inc.

  4. The interplay of stress and sleep impacts BDNF level.

    Science.gov (United States)

    Giese, Maria; Unternaehrer, Eva; Brand, Serge; Calabrese, Pasquale; Holsboer-Trachsler, Edith; Eckert, Anne

    2013-01-01

    Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF) could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS) and/or Periodic Limb Movement (PLM) and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index) and stress (PSS, Perceived Stress Scale) and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while others develop a mental disorder.

  5. The interplay of stress and sleep impacts BDNF level.

    Directory of Open Access Journals (Sweden)

    Maria Giese

    Full Text Available BACKGROUND: Sleep plays a pivotal role in normal biological functions. Sleep loss results in higher stress vulnerability and is often found in mental disorders. There is evidence that brain-derived neurotrophic factor (BDNF could be a central player in this relationship. Recently, we could demonstrate that subjects suffering from current symptoms of insomnia exhibited significantly decreased serum BDNF levels compared with sleep-healthy controls. In accordance with the paradigm indicating a link between sleep and BDNF, we aimed to investigate if the stress system influences the association between sleep and BDNF. METHODOLOGY/PRINCIPAL FINDINGS: Participants with current symptoms of insomnia plus a former diagnosis of Restless Legs Syndrome (RLS and/or Periodic Limb Movement (PLM and sleep healthy controls were included in the study. They completed questionnaires on sleep (ISI, Insomnia Severity Index and stress (PSS, Perceived Stress Scale and provided a blood sample for determination of serum BDNF. We found a significant interaction between stress and insomnia with an impact on serum BDNF levels. Moreover, insomnia severity groups and score on the PSS each revealed a significant main effect on serum BDNF levels. Insomnia severity was associated with increased stress experience affecting serum BDNF levels. Of note, the association between stress and BDNF was only observed in subjects without insomnia. Using a mediation model, sleep was revealed as a mediator of the association between stress experience and serum BDNF levels. CONCLUSIONS: This is the first study to show that the interplay between stress and sleep impacts BDNF levels, suggesting an important role of this relationship in the pathogenesis of stress-associated mental disorders. Hence, we suggest sleep as a key mediator at the connection between stress and BDNF. Whether sleep is maintained or disturbed might explain why some individuals are able to handle a certain stress load while

  6. Sleep in Elite Athletes and Nutritional Interventions to Enhance Sleep

    OpenAIRE

    Halson, Shona L.

    2014-01-01

    Sleep has numerous important physiological and cognitive functions that may be particularly important to elite athletes. Recent evidence, as well as anecdotal information, suggests that athletes may experience a reduced quality and/or quantity of sleep. Sleep deprivation can have significant effects on athletic performance, especially submaximal, prolonged exercise. Compromised sleep may also influence learning, memory, cognition, pain perception, immunity and inflammation. Furthermore, chang...

  7. The whole is not the sum of its parts: Specific types of positive affect influence sleep differentially.

    Science.gov (United States)

    Pressman, Sarah D; Jenkins, Brooke N; Kraft-Feil, Tara L; Rasmussen, Heather; Scheier, Michael F

    2017-08-01

    Given the known detrimental effects of poor sleep on an array of psychological and physical health processes, it is critical to understand the factors that protect sleep, especially during times of stress when sleep particularly suffers. Positive affect (PA) arises as a variable of interest given its known associations with health and health behaviors and its ability to buffer stress. In 2 studies, we examined which types of PA (distinguished by arousal level and trait/state measurement) were most beneficial for sleep and whether these associations varied depending on the stress context. In Study 1, college students (N = 99) reported on their PA and sleep during the week of a major exam. In Study 2, 2 weeks of daily PA and sleep data were collected during a period with no examinations in a similar sample of students (N = 83). Results indicated that high trait vigor was tied to better sleep efficiency and quality, especially during high stress. Trait calm was generally unhelpful to sleep, and was related negatively to sleep duration. State calm, on the other hand, interacted with stress in Study 2 to predict more efficient day-to-day sleep on days with higher average stress. These findings illustrate the importance of considering arousal level, affect duration, and the stress context in studies of PA and health. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Loss of Melanopsin Photoreception and Antagonism of the Histamine H3 Receptor by Ciproxifan Inhibit Light-Induced Sleep in Mice.

    Directory of Open Access Journals (Sweden)

    Fanuel Muindi

    Full Text Available Light has direct effects on sleep and wakefulness causing arousal in diurnal animals and sleep in nocturnal animals. In the present study, we assessed the modulation of light-induced sleep by melanopsin and the histaminergic system by exposing mice to millisecond light flashes and continuous light respectively. First, we show that the induction of sleep by millisecond light flashes is dose dependent as a function of light flash number. We found that exposure to 60 flashes of light occurring once every 60 seconds for 1-h (120-ms of total light over an hour induced a similar amount of sleep as a continuous bright light pulse. Secondly, the induction of sleep by millisecond light flashes was attenuated in the absence of melanopsin when animals were presented with flashes occurring every 60 seconds over a 3-h period beginning at ZT13. Lastly, the acute administration of a histamine H3 autoreceptor antagonist, ciproxifan, blocked the induction of sleep by a 1-h continuous light pulse during the dark period. Ciproxifan caused a decrease in NREMS delta power and an increase in theta activity during both sleep and wake periods respectively. The data suggest that some form of temporal integration occurs in response to millisecond light flashes, and that this process requires melanopsin photoreception. Furthermore, the pharmacological data suggest that the increase of histaminergic neurotransmission is sufficient to attenuate the light-induced sleep response during the dark period.

  9. Sleep Disorders

    DEFF Research Database (Denmark)

    Rahbek Kornum, Birgitte; Mignot, Emmanuel

    2014-01-01

    mediates circadian regulation of sleep. Misalignment with the rhythm of the sun results in circadian disorders and jet lag. The molecular basis of homeostatic sleep regulation is mostly unknown. A network of mutually inhibitory brain nuclei regulates sleep states and sleep-wake transitions. Abnormalities...... in these networks create sleep disorders, including rapid eye movement sleep behavior disorder, sleep walking, and narcolepsy. Physiological changes associated with sleep can be imbalanced, resulting in excess movements such as periodic leg movements during sleep or abnormal breathing in obstructive sleep apneas....... As every organ in the body is affected by sleep directly or indirectly, sleep and sleep-associated disorders are frequent and only now starting to be understood....

  10. Parents' communication decision for children with hearing loss: sources of information and influence.

    Science.gov (United States)

    Decker, Kalli B; Vallotton, Claire D; Johnson, Harold A

    2012-01-01

    Choosing a method of communication for a child with hearing loss is a complex process that must occur early to prevent developmental consequences. Research shows that parents' decisions are influenced by professionals; parental attitudes and knowledge also may be influential. The present study investigated additional influences on parents' choices; data were collected via an online survey (N = 36). Results indicated no effects of parents' knowledge of development on their communication choices, but did indicate an effect of parents' values and priorities for their children. Further, parents who chose speech only received information from education or speech/audiology professionals more often. However, there were no group differences in sources parents cited as influential; all parents relied on their own judgment. Results suggest that parents internalize the opinions of professionals. Thus, accurate information from professionals is necessary for parents to make informed decisions about their children's communication.

  11. Acute sleep deprivation increases portion size and affects food choice in young men.

    Science.gov (United States)

    Hogenkamp, Pleunie S; Nilsson, Emil; Nilsson, Victor C; Chapman, Colin D; Vogel, Heike; Lundberg, Lina S; Zarei, Sanaz; Cedernaes, Jonathan; Rångtell, Frida H; Broman, Jan-Erik; Dickson, Suzanne L; Brunstrom, Jeffrey M; Benedict, Christian; Schiöth, Helgi B

    2013-09-01

    Acute sleep loss increases food intake in adults. However, little is known about the influence of acute sleep loss on portion size choice, and whether this depends on both hunger state and the type of food (snack or meal item) offered to an individual. The aim of the current study was to compare portion size choice after a night of sleep and a period of nocturnal wakefulness (a condition experienced by night-shift workers, e.g. physicians and nurses). Sixteen men (age: 23 ± 0.9 years, BMI: 23.6 ± 0.6 kg/m(2)) participated in a randomized within-subject design with two conditions, 8-h of sleep and total sleep deprivation (TSD). In the morning following sleep interventions, portion size, comprising meal and snack items, was measured using a computer-based task, in both fasted and sated state. In addition, hunger as well as plasma levels of ghrelin were measured. In the morning after TSD, subjects had increased plasma ghrelin levels (13%, p=0.04), and chose larger portions (14%, p=0.02), irrespective of the type of food, as compared to the sleep condition. Self-reported hunger was also enhanced (pchoice after sleep loss depend on both an individual's hunger status, and the type of food offered. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Influence of steam generator tube ruptures during semiscale loss-of-coolant experiments

    International Nuclear Information System (INIS)

    Cozzuol, J.M.; Larson, T.K.

    1978-01-01

    Examination of the U-tubes in the steam generators of some large commercial pressurized water reactors (PWR) has revealed the existence of leakage and in some cases structural weakening of the tubes. This structural weakening enhances the possibility of tubes rupturing during a hypothesized loss-of-coolant accident (LOCA). Considerable interest has been shown in the analysis of tube ruptures concurrent with a hypothesized LOCA since the presence of tube ruptures has the potential to influence the system thermal-hydraulic response and could foreseeably result in a more severe core thermal behavior than might otherwise occur. To experimentally investigate the influence of steam generator tube ruptures on the thermal-hydraulic response of PWR type system, a series of experiments was conducted in the Semiscale Mod-1 system by EG and G Idaho, Inc., for the U.S. Nuclear Regulatory Commission and the Department of Energy. The primary objective of the experiments was to obtain data which could be used to evaluate the influence of the simulated tube ruptures on the system and core thermal-hydraulic response for a range of tube ruptures that was expected to provide the potential for high cladding temperatures in the Semiscale facility. The experiments were conducted assuming a variety in the number of tubes ruptured during large break loss-of-coolant conditions. The number of experiments conducted permitted determination of the range of tube ruptures for which high peak cladding temperatures could result in the Semiscale Mod-1 system. The paper contains a description of the Semiscale Mod-1 system and a discussion of the steam generator tube rupture tests conducted. The experimental results from the test series and the thermal-hydraulic phenomena found to influence the core thermal response during the experiments are discussed

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

    Science.gov (United States)

    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.

  14. Assessing the influence of sustainable trail design and maintenance on soil loss

    Science.gov (United States)

    Marion, Jeff; Wimpey, Jeremy

    2017-01-01

    Natural-surfaced trail systems are an important infrastructure component providing a means for accessing remote protected natural area destinations. The condition and usability of trails is a critical concern of land managers charged with providing recreational access while preserving natural conditions, and to visitors seeking high quality recreational opportunities and experiences. While an adequate number of trail management publications provide prescriptive guidance for designing, constructing, and maintaining natural-surfaced trails, surprisingly little research has been directed at providing a scientific basis for this guidance. Results from a review of the literature and three scientific studies are presented to model and clarify the influence of factors that substantially influence trail soil loss and that can be manipulated by trail professionals to sustain high traffic while minimizing soil loss over time. Key factors include trail grade, slope alignment angle, tread drainage features, and the amount of rock in tread substrates. A new Trail Sustainability Rating is developed and offered as a tool for evaluating or improving the sustainability of existing or new trails.

  15. Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

    Energy Technology Data Exchange (ETDEWEB)

    Tangler, J.L. [National Renewable Energy Laboratory, Golden, Colorado (United States)

    1997-08-01

    The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. (au)

  16. Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

    Energy Technology Data Exchange (ETDEWEB)

    Tangler, J.L. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. 8 refs., 6 figs.

  17. Assessing the influence of sustainable trail design and maintenance on soil loss.

    Science.gov (United States)

    Marion, Jeffrey L; Wimpey, Jeremy

    2017-03-15

    Natural-surfaced trail systems are an important infrastructure component providing a means for accessing remote protected natural area destinations. The condition and usability of trails is a critical concern of land managers charged with providing recreational access while preserving natural conditions, and to visitors seeking high quality recreational opportunities and experiences. While an adequate number of trail management publications provide prescriptive guidance for designing, constructing, and maintaining natural-surfaced trails, surprisingly little research has been directed at providing a scientific basis for this guidance. Results from a review of the literature and three scientific studies are presented to model and clarify the influence of factors that substantially influence trail soil loss and that can be manipulated by trail professionals to sustain high traffic while minimizing soil loss over time. Key factors include trail grade, slope alignment angle, tread drainage features, and the amount of rock in tread substrates. A new Trail Sustainability Rating is developed and offered as a tool for evaluating or improving the sustainability of existing or new trails. Published by Elsevier Ltd.

  18. AC loss performance of cable-in-conduit conductor. Influence of cable mechanical property on coupling loss reduction

    International Nuclear Information System (INIS)

    Matsui, Kunihiro; Koizumi, Norikiyo; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko

    2003-01-01

    The ITER Central Solenoid (CS) model coil, CS Insert and Nb 3 Al Insert were developed and tested from 2000 to 2002. The AC loss performances of these coils were investigated in various experiments. In addition, the AC losses of the CS and Nb 3 Al Insert conductors were measured using short CS and Nb 3 Al Insert conductors before the coil tests. The coupling time constants of these conductors were estimated to be 30 and 120 ms, respectively. On the other hand, the test results of the CS and Nb 3 Al Inserts show that the coupling currents induced in these conductors had multiple decay time constants. In fact, the existence of the coupling currents with long decay time constants, the order of which was in the thousands of seconds, was directly observed with hall sensors and voltage taps. Moreover, the AC loss test results show that electromagnetic force decreases coupling losses with exponential decay constants. This is because the weak sinter among the strands, which originated during heat treatment, was broken due to the electromagnetic force, and then the contact resistance among strands increased. It was found that this exponential decay constant was the function of a gap (i.e., a mechanical property of the cable) created between the cable and conduit due to electromagnetic force. The gap can be estimated by pressure drop, measured under the electromagnetic force. The pressure drop can easily be measured at an initial trial charge, and then it is possible to estimate the exponential decay constant before normal coil operation. Accordingly, it is possible to predict promptly how many times the trial operations are necessary to decrease the coupling losses to the designed value by measuring the coupling losses and the pressure drop during the initial coil operation trial. (author)

  19. Sleep disorders, obesity, and aging: the role of orexin.

    Science.gov (United States)

    Nixon, Joshua P; Mavanji, Vijayakumar; Butterick, Tammy A; Billington, Charles J; Kotz, Catherine M; Teske, Jennifer A

    2015-03-01

    The hypothalamic neuropeptides orexin A and B (hypocretin 1 and 2) are important homeostatic mediators of central control of energy metabolism and maintenance of sleep/wake states. Dysregulation or loss of orexin signaling has been linked to narcolepsy, obesity, and age-related disorders. In this review, we present an overview of our current understanding of orexin function, focusing on sleep disorders, energy balance, and aging, in both rodents and humans. We first discuss animal models used in studies of obesity and sleep, including loss of function using transgenic or viral-mediated approaches, gain of function models using exogenous delivery of orexin receptor agonist, and naturally-occurring models in which orexin responsiveness varies by individual. We next explore rodent models of orexin in aging, presenting evidence that orexin loss contributes to age-related changes in sleep and energy balance. In the next section, we focus on clinical importance of orexin in human obesity, sleep, and aging. We include discussion of orexin loss in narcolepsy and potential importance of orexin in insomnia, correlations between animal and human studies of age-related decline, and evidence for orexin involvement in age-related changes in cognitive performance. Finally, we present a summary of recent studies of orexin in neurodegenerative disease. We conclude that orexin acts as an integrative homeostatic signal influencing numerous brain regions, and that this pivotal role results in potential dysregulation of multiple physiological processes when orexin signaling is disrupted or lost. Published by Elsevier B.V.

  20. Subjective sleep efficiency of hemodialysis patients

    NARCIS (Netherlands)

    Koch, B.C.P.; Nagtegaal, J.E.; Hagen, E.C.; van Dorp, W.Th.; Boringa, J.B.S.; Kerkhof, G.A.; ter Wee, P.M.

    2008-01-01

    Background: Sleep disturbances have a major influence on quality of life. A commonly used measure of sleep disturbances is sleep efficiency. The purpose of this study was to investigate the prevalence of decreased subjective sleep efficiency in hemodialysis patients. An additional goal was to

  1. Morning-evening type and burnout level as factors influencing sleep quality of shift nurses: a questionnaire study

    Science.gov (United States)

    Demir Zencirci, Ayten; Arslan, Sümeyye

    2011-01-01

    Aim To assess the relationship between sleep quality and demographic variables, morning-evening type, and burnout in nurses who work shifts. Methods We carried out a cross-sectional self-administered study with forced choice and open-ended structured questionnaires – Pittsburg Sleep Quality Index, Morningness-eveningness Questionnaire, and Maslach Burnout Inventory. The study was carried out at Gazi University Medicine Faculty Hospital of Ankara on 524 invited nurses from July to September 2008, with a response rate of 89.94% (n = 483). Descriptive and inferential statistics were applied to determine the risk factors of poor sleep quality. Results Most socio-demographic variables did not affect sleep quality. Participants with poor sleep quality had quite high burnout levels. Most nurses who belonged to a type that is neither morning nor evening had poor sleep quality. Nurses who experienced an incident worsening their sleep patterns (P burnout dimensions were high. Conclusions Nurses working consistently either in the morning or at night had better sleep quality than those working rotating shifts. Further studies are still needed to develop interventions that improve sleep quality and decrease burnout in nurses working shifts. PMID:21853548

  2. Sleep in elite athletes and nutritional interventions to enhance sleep.

    Science.gov (United States)

    Halson, Shona L

    2014-05-01

    Sleep has numerous important physiological and cognitive functions that may be particularly important to elite athletes. Recent evidence, as well as anecdotal information, suggests that athletes may experience a reduced quality and/or quantity of sleep. Sleep deprivation can have significant effects on athletic performance, especially submaximal, prolonged exercise. Compromised sleep may also influence learning, memory, cognition, pain perception, immunity and inflammation. Furthermore, changes in glucose metabolism and neuroendocrine function as a result of chronic, partial sleep deprivation may result in alterations in carbohydrate metabolism, appetite, food intake and protein synthesis. These factors can ultimately have a negative influence on an athlete's nutritional, metabolic and endocrine status and hence potentially reduce athletic performance. Research has identified a number of neurotransmitters associated with the sleep-wake cycle. These include serotonin, gamma-aminobutyric acid, orexin, melanin-concentrating hormone, cholinergic, galanin, noradrenaline, and histamine. Therefore, nutritional interventions that may act on these neurotransmitters in the brain may also influence sleep. Carbohydrate, tryptophan, valerian, melatonin and other nutritional interventions have been investigated as possible sleep inducers and represent promising potential interventions. In this review, the factors influencing sleep quality and quantity in athletic populations are examined and the potential impact of nutritional interventions is considered. While there is some research investigating the effects of nutritional interventions on sleep, future research may highlight the importance of nutritional and dietary interventions to enhance sleep.

  3. The influence of woody encroachment on the nitrogen cycle: fixation, storage and gas loss

    Science.gov (United States)

    Soper, F.; Sparks, J. P.

    2015-12-01

    Woody encroachment is a pervasive land cover change throughout the tropics and subtropics. Encroachment is frequently catalyzed by nitrogen (N)-fixing trees and the resulting N inputs potentially alter whole-ecosystem N cycling, accumulation and loss. In the southern US, widespread encroachment by legume Prosopis glandulosa is associated with increased soil total N storage, inorganic N concentrations, and net mineralization and nitrification rates. To better understand the effects of this process on ecosystem N cycling, we investigated patterns of symbiotic N fixation, N accrual and soil N trace gas and N2 emissions during Prosopis encroachment into the southern Rio Grande Plains. Analyses of d15N in foliage, xylem sap and plant-available soil N suggested that N fixation rates increase with tree age and are influenced by abiotic conditions. A model of soil N accrual around individual trees, accounting for atmospheric inputs and gas losses, generates lifetimes N fixation estimates of up to 9 kg for a 100-year-old tree and current rates of 7 kg N ha-1 yr-1. However, these N inputs and increased soil cycling rates do not translate into increased N gas losses. Two years of field measurements of a complete suite of N trace gases (ammonia, nitrous oxide, nitric oxide and other oxidized N compounds) found no difference in flux between upland Prosopis groves and adjacent unencroached grasslands. Total emissions for both land cover types average 0.56-0.65 kg N ha-1 yr-1, comparable to other southern US grasslands. Additional lab experiments suggested that N2 losses are low and that field oxygen conditions are not usually conducive to denitrification. Taken together, results suggest that this ecosystem is currently experiencing a period of net N accrual under ongoing encroachment.

  4. Quantity and quality of food losses along the Swiss potato supply chain: Stepwise investigation and the influence of quality standards on losses.

    Science.gov (United States)

    Willersinn, Christian; Mack, Gabriele; Mouron, Patrik; Keiser, Andreas; Siegrist, Michael

    2015-12-01

    This paper presents the results of a stepwise investigation of the quantity and quality of food losses along the Swiss potato supply chain. Quantitative data were collected from field trials, from structured interviews with wholesalers, processors and retailers, and from consumer surveys in combination with a 30-day diary study. The "Swiss trade customs for potatoes" pose the basis for the qualitative evaluation of losses. The influences of technological, institutional (business and economy; legislation and policy), and social drivers on the generation of fresh potato and processed potato products losses were assessed. Losses due to quality standards driven by food safety and consumer preferences for certain aesthetic standards have been evaluated too. Across the entire potato value chain, approximately 53-55% of the initial fresh potato production and 41-46% of the initial processing potato production are finally lost. Losses between organic and non-organic supply chains differ from 2% to 5%. From the total initial fresh potato production, 15-24% gets lost during agricultural production, a further 12-24% at wholesalers, 1-3% at retailers, and 15% at private households. In comparison, 5-11% of the initial production gets lost at wholesalers, a further 14-15% during processing, 0% at retailers, and 2% at private households. Losses during agricultural production do not vary much (13-25%) between fresh and processing potatoes. Approximately half of total potato losses occur because potatoes do not meet quality standards. 25-34% of these quality-driven losses are caused by food safety reasons, and the remainder are caused by consumer preferences or suitability for storage. In total, social drivers (e.g., consumer preferences, behavior, or socio-demographical factors) are responsible for two-thirds to three-fourths of all fresh potato losses and 40-45% of all processing potato losses. Technological drivers cause circa one-third of the total processing potato losses. The

  5. Sleep Quiz

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Sleep Quiz Past Issues / Summer 2007 Table of Contents ... on. Photo: iStock Take the National Center on Sleep Disorders Research Sleep Quiz TRUE OR FALSE ? _____1. ...

  6. The Function of Sleep

    Directory of Open Access Journals (Sweden)

    Daniel A. Barone

    2015-06-01

    Full Text Available The importance of sleep can be ascertained by noting the effects of its loss, which tends to be chronic and partial, on cognition, mood, alertness, and overall health. Many theories have been put forth to explain the function of sleep in humans, including proposals based on energy conservation, ecological adaptations, neurocognitive function, neural plasticity, nervous system and physical health, and performance. Most account for only a portion of sleep behavior and few are based on strong experimental support. In this review, we present theories proposing why sleep is necessary and supporting data demonstrating the effects of inadequate sleep, with the intention of gleaning further information as to its necessity, which remains one of the most perplexing mysteries in biology.

  7. Influence of a Vertical Cutting Device on Brassica Napus Seed Loss in Direct Combining

    Energy Technology Data Exchange (ETDEWEB)

    Pari, L.; Fedrizzi, M.; Assirelli, A. (Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Unita di Ricerca per l' Ingegneria Agraria, Monterotondo, RM (Italy))

    2008-10-15

    EU requires that by 2010 5.65% of diesel fuel must be of vegetable origin. To reduce Italian dependence from imported palm oil, it is necessary to increase national production of vegetable oils: together with sunflower and soybean, canola (Brassica napus or Brassica napus oleifera) is an interesting possibility to satisfy vegetable oil demand, that is rapidly increasing for its use in biodiesel production. In Italy potential areas are available for the cultivation in relation to adequate rainfall and mild winters, that are very promising factors for canola production. However, the long period of seed maturity, non uniform growth, natural dehiscent process and variable weather conditions, such as wind and rain, are some of the factors which can lead to large seed losses: this is the main problem limiting this specie diffusion. Amongst available harvesting techniques, direct harvest of canola is an hazardous practice because there are several important questions related to it. The success of canola may depend on research initiatives to reduce some of the obstacles associated with its growing. The objective of this study is to determine if different cropping heads in direct combining can reduce seed losses. In Northern Italy (Piedmont) the trials were conducted in a 16 ha canola cultivation, in which was seeded the -Lion variety of canola. In order to realize direct harvest, the combine cylinder speed was regulated as slow as possible (500 rpm), the concave was opened at 3/4 of the way (about 25 mm clearance) and the fan speed was set at 2/3 of small grain settings (800 rpm). Only one combine was used for the trials, a New Holland CX 9080, in order to avoid any influence on seed losses. The combine was equipped with two different cutting heads: a common wheat type (type 1) and another, similar to the first, but equipped with vertical cutting devices on both ends of the head (type 2), because the plants are very dense and entangled. The losses of seeds were measured

  8. Environmental influences on small eating behavior change to promote weight loss among Black and Hispanic populations.

    Science.gov (United States)

    Eldridge, Johanna D; Devine, Carol M; Wethington, Elaine; Aceves, Luz; Phillips-Caesar, Erica; Wansink, Brian; Charlson, Mary E

    2016-01-01

    Small eating behavior changes are proposed as more feasible to achieve and maintain than larger changes used in traditional behavioral weight loss studies. However, it is unclear whether overweight Black and Hispanic adults in a low-income urban setting experience small changes as feasible and what might influence feasibility. Participants' experiences in a 12-week pilot weight loss intervention were explored qualitatively to determine the feasibility of making small eating behavior changes in this population. After the intervention (69% retention), semi-structured interviews with 46 men and women (mean age 51, 50% Non-Hispanic Black, 43% Hispanic) revealed that making small eating changes was a process shaped by participants' intrapersonal and interpersonal eating environments. Participants responded to intrapersonal and interpersonal eating environmental challenges by adapting small change strategies, navigating eating environments, and negotiating household eating practices. Findings highlight how even small eating behavior changes called for adaptation, navigation, and negotiation of complex eating environments in daily life. These findings were used to improve the trial that followed and underline the importance of feasibility studies to inform community trials. Findings also add to understanding of contextual challenges and the skills needed to implement small changes in a low income, ethnic minority population. Copyright © 2015. Published by Elsevier Ltd.

  9. Limited influence of climate change mitigation on short-term glacier mass loss

    Science.gov (United States)

    Marzeion, Ben; Kaser, Georg; Maussion, Fabien; Champollion, Nicolas

    2018-04-01

    Glacier mass loss is a key contributor to sea-level change1,2, slope instability in high-mountain regions3,4 and the changing seasonality and volume of river flow5-7. Understanding the causes, mechanisms and time scales of glacier change is therefore paramount to identifying successful strategies for mitigation and adaptation. Here, we use temperature and precipitation fields from the Coupled Model Intercomparison Project Phase 5 output to force a glacier evolution model, quantifying mass responses to future climatic change. We find that contemporary glacier mass is in disequilibrium with the current climate, and 36 ± 8% mass loss is already committed in response to past greenhouse gas emissions. Consequently, mitigating future emissions will have only very limited influence on glacier mass change in the twenty-first century. No significant differences between 1.5 and 2 K warming scenarios are detectable in the sea-level contribution of glaciers accumulated within the twenty-first century. In the long-term, however, mitigation will exert strong control, suggesting that ambitious measures are necessary for the long-term preservation of glaciers.

  10. Sleep As A Strategy For Optimizing Performance.

    Science.gov (United States)

    Yarnell, Angela M; Deuster, Patricia

    2016-01-01

    Recovery is an essential component of maintaining, sustaining, and optimizing cognitive and physical performance during and after demanding training and strenuous missions. Getting sufficient amounts of rest and sleep is key to recovery. This article focuses on sleep and discusses (1) why getting sufficient sleep is important, (2) how to optimize sleep, and (3) tools available to help maximize sleep-related performance. Insufficient sleep negatively impacts safety and readiness through reduced cognitive function, more accidents, and increased military friendly-fire incidents. Sufficient sleep is linked to better cognitive performance outcomes, increased vigor, and better physical and athletic performance as well as improved emotional and social functioning. Because Special Operations missions do not always allow for optimal rest or sleep, the impact of reduced rest and sleep on readiness and mission success should be minimized through appropriate preparation and planning. Preparation includes periods of "banking" or extending sleep opportunities before periods of loss, monitoring sleep by using tools like actigraphy to measure sleep and activity, assessing mental effectiveness, exploiting strategic sleep opportunities, and consuming caffeine at recommended doses to reduce fatigue during periods of loss. Together, these efforts may decrease the impact of sleep loss on mission and performance. 2016.

  11. Sleep spindle density in narcolepsy

    DEFF Research Database (Denmark)

    Christensen, Julie Anja Engelhard; Nikolic, Miki; Hvidtfelt, Mathias

    2017-01-01

    BACKGROUND: Patients with narcolepsy type 1 (NT1) show alterations in sleep stage transitions, rapid-eye-movement (REM) and non-REM sleep due to the loss of hypocretinergic signaling. However, the sleep microstructure has not yet been evaluated in these patients. We aimed to evaluate whether...... the sleep spindle (SS) density is altered in patients with NT1 compared to controls and patients with narcolepsy type 2 (NT2). METHODS: All-night polysomnographic recordings from 28 NT1 patients, 19 NT2 patients, 20 controls (C) with narcolepsy-like symptoms, but with normal cerebrospinal fluid hypocretin...... levels and multiple sleep latency tests, and 18 healthy controls (HC) were included. Unspecified, slow, and fast SS were automatically detected, and SS densities were defined as number per minute and were computed across sleep stages and sleep cycles. The between-cycle trends of SS densities in N2...

  12. Sleep and academic performance of Portuguese teenagers

    OpenAIRE

    Pestana, Leonor; Duarte, João; Coutinho, Emília; Nelas, Paula; Chaves, Cláudia; Amaral, Odete

    2016-01-01

    Abstract: Sleep has numerous important functions in the body, such as consolidation of memory, concentration and learning. Changes in sleep cycles in adolescents lead to sleep deprivation with consequences to academic performance. Our research question was What are the sleep habits that influence school performance (study environment, study planning, study method, reading skills, motivation to study, overall school performance) in adolescents? We aimed to identify sleep habits predictors of t...

  13. [Influencing factors for hearing loss in workers exposed to noise in a cement plant].

    Science.gov (United States)

    Wang, X M; Wu, H; Jiao, J; Li, Y H; Zhang, Z R; Zhou, W H; Yu, S F

    2016-12-20

    Objective: To investigate the incidence of noise-induced hearing loss (NIHL) and related influencing factors in workers exposed to noise in a cement plant. Methods: In October 2015, cluster sampling was used for questionnaire investigation and health examination of workers exposed to noise in a cement plant in Henan Province, China. The association of demographic features, living habits, cumulative noise exposure (CNE) , hypertension, and hyperlipidemia with NIHL was analyzed. Results: There was mainly medium-or high-frequency noise in the working place of this cement plant. The prevalence rate of NIHL was 18.4%, and male workers had a significantly higher prevalence rate than female workers (χ(2)=28.09, P workers who smoked had a significantly higher prevalence rate of NIHL than those who did not smoke (χ(2)=14.15, P workers with a drinking habit had a significantly higher prevalence rate of NIHL than those without such habit (χ(2)=7.95, P workers who did not wear earplugs had a significantly higher prevalence rate of NIHL than those who wore earplugs (χ(2)=19.93, P workers with hyperlipidemiahad a significantly higher prevalence rate of NIHL than those without hyperlipidemia (χ(2)=12.43, P workers in a cement plant have a high prevalence rate of NIHL, and CNE, sex, age, degree of education, use of earplugs, and hyperlipidemia may be influencing factors for NIHL.

  14. The impact of disaster work on community volunteers: The role of peri-traumatic distress, level of personal affectedness, sleep quality and resource loss, on post-traumatic stress disorder symptoms and subjective health.

    Science.gov (United States)

    Thormar, Sigridur B; Gersons, Berthold P R; Juen, Barbara; Djakababa, Maria Nelden; Karlsson, Thorlakur; Olff, Miranda

    2014-12-01

    Disaster work has shown to cause PTSD symptoms and subjective health complaints in professional emergency personnel. However, very little is known about how disaster work affects community volunteers. This first time longitudinal study examined factors contributing to post-traumatic stress disorder symptoms (PTSD) and subjective health complaints in volunteers working in an earthquake setting. At six and eighteen months post disaster, a sample of 506 Indonesian Red Cross volunteers were assessed using the Impact of Event Scale-Revised and the Subjective Health Complaints Inventory. Factors analyzed in relation to the outcomes included: peri-traumatic distress, level of personal affectedness by the disaster, sleep quality and loss of resources as a consequence of the disaster. At 18 months post-disaster the findings showed high levels of PTSD symptoms and subjective health complaints. Quality of sleep was related to both outcomes but resource loss only to PTSD symptoms. Neither peri-traumatic distress nor level of affectedness by the disaster (external versus directly affected volunteers), were predictive of symptoms. This study indicates that characteristics of disaster work e.g. low quality of sleep, may be an important contributor to PTSD symptoms and subjective health complaints in volunteers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Sleep Deprivation Impairs the Human Central and Peripheral Nervous System Discrimination of Social Threat.

    Science.gov (United States)

    Goldstein-Piekarski, Andrea N; Greer, Stephanie M; Saletin, Jared M; Walker, Matthew P

    2015-07-15

    Facial expressions represent one of the most salient cues in our environment. They communicate the affective state and intent of an individual and, if interpreted correctly, adaptively influence the behavior of others in return. Processing of such affective stimuli is known to require reciprocal signaling between central viscerosensory brain regions and peripheral-autonomic body systems, culminating in accurate emotion discrimination. Despite emerging links between sleep and affective regulation, the impact of sleep loss on the discrimination of complex social emotions within and between the CNS and PNS remains unknown. Here, we demonstrate in humans that sleep deprivation impairs both viscerosensory brain (anterior insula, anterior cingulate cortex, amygdala) and autonomic-cardiac discrimination of threatening from affiliative facial cues. Moreover, sleep deprivation significantly degrades the normally reciprocal associations between these central and peripheral emotion-signaling systems, most prominent at the level of cardiac-amygdala coupling. In addition, REM sleep physiology across the sleep-rested night significantly predicts the next-day success of emotional discrimination within this viscerosensory network across individuals, suggesting a role for REM sleep in affective brain recalibration. Together, these findings establish that sleep deprivation compromises the faithful signaling of, and the "embodied" reciprocity between, viscerosensory brain and peripheral autonomic body processing of complex social signals. Such impairments hold ecological relevance in professional contexts in which the need for accurate interpretation of social cues is paramount yet insufficient sleep is pervasive. Copyright © 2015 the authors 0270-6474/15/3510135-11$15.00/0.

  16. Effects of different sleep deprivation protocols on sleep perception in healthy volunteers.

    Science.gov (United States)

    Goulart, Leonardo I; Pinto, Luciano R; Perlis, Michael L; Martins, Raquel; Caboclo, Luis Otavio; Tufik, Sergio; Andersen, Monica L

    2014-10-01

    To investigate whether different protocols of sleep deprivation modify sleep perception. The effects of total sleep deprivation (TD) and selective rapid eye movement (REM) sleep deprivation (RD) on sleep perception were analyzed in normal volunteers. Thirty-one healthy males with normal sleep were randomized to one of three conditions: (i) normal uninterrupted sleep; (ii) four nights of RD; or (iii) two nights of TD. Morning perception of total sleep time was evaluated for each condition. Sleep perception was estimated using total sleep time (in hours) as perceived by the volunteer divided by the total sleep time (in hours) measured by polysomnography (PSG). The final value of this calculation was defined as the perception index (PI). There were no significant differences among the three groups of volunteers in the total sleep time measured by PSG or in the perception of total sleep time at baseline condition. Volunteers submitted to RD exhibited lower sleep PI scores as compared with controls during the sleep deprivation period (P sleep deprivation reduced the ability of healthy young volunteers to perceive their total sleep time when compared with time measured by PSG. The data reinforce the influence of sleep deprivation on sleep perception. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Sustained sleep fragmentation induces sleep homeostasis in mice

    KAUST Repository

    Baud, Maxime O.; Magistretti, Pierre J.; Petit, Jean Marie

    2015-01-01

    Study Objectives: Sleep fragmentation (SF) is an integral feature of sleep apnea and other prevalent sleep disorders. Although the effect of repetitive arousals on cognitive performance is well documented, the effects of long-term SF on electroencephalography (EEG) and molecular markers of sleep homeostasis remain poorly investigated. To address this question, we developed a mouse model of chronic SF and characterized its effect on EEG spectral frequencies and the expression of genes previously linked to sleep homeostasis including clock genes, heat shock proteins, and plasticity-related genes. Design: N/A. Setting: Animal sleep research laboratory. Participants : Sixty-six C57BL6/J adult mice. Interventions: Instrumental sleep disruption at a rate of 60/h during 14 days Measurements and Results: Locomotor activity and EEG were recorded during 14 days of SF followed by recovery for 2 days. Despite a dramatic number of arousals and decreased sleep bout duration, SF minimally reduced total quantity of sleep and did not significantly alter its circadian distribution. Spectral analysis during SF revealed a homeostatic drive for slow wave activity (SWA; 1-4 Hz) and other frequencies as well (4-40 Hz). Recordings during recovery revealed slow wave sleep consolidation and a transient rebound in SWA, and paradoxical sleep duration. The expression of selected genes was not induced following chronic SF. Conclusions: Chronic sleep fragmentation (SF) increased sleep pressure confirming that altered quality with preserved quantity triggers core sleep homeostasis mechanisms. However, it did not induce the expression of genes induced by sleep loss, suggesting that these molecular pathways are not sustainably activated in chronic diseases involving SF.

  18. Sustained sleep fragmentation induces sleep homeostasis in mice

    KAUST Repository

    Baud, Maxime O.

    2015-04-01

    Study Objectives: Sleep fragmentation (SF) is an integral feature of sleep apnea and other prevalent sleep disorders. Although the effect of repetitive arousals on cognitive performance is well documented, the effects of long-term SF on electroencephalography (EEG) and molecular markers of sleep homeostasis remain poorly investigated. To address this question, we developed a mouse model of chronic SF and characterized its effect on EEG spectral frequencies and the expression of genes previously linked to sleep homeostasis including clock genes, heat shock proteins, and plasticity-related genes. Design: N/A. Setting: Animal sleep research laboratory. Participants : Sixty-six C57BL6/J adult mice. Interventions: Instrumental sleep disruption at a rate of 60/h during 14 days Measurements and Results: Locomotor activity and EEG were recorded during 14 days of SF followed by recovery for 2 days. Despite a dramatic number of arousals and decreased sleep bout duration, SF minimally reduced total quantity of sleep and did not significantly alter its circadian distribution. Spectral analysis during SF revealed a homeostatic drive for slow wave activity (SWA; 1-4 Hz) and other frequencies as well (4-40 Hz). Recordings during recovery revealed slow wave sleep consolidation and a transient rebound in SWA, and paradoxical sleep duration. The expression of selected genes was not induced following chronic SF. Conclusions: Chronic sleep fragmentation (SF) increased sleep pressure confirming that altered quality with preserved quantity triggers core sleep homeostasis mechanisms. However, it did not induce the expression of genes induced by sleep loss, suggesting that these molecular pathways are not sustainably activated in chronic diseases involving SF.

  19. Influence of computer games on the sleep quality and the nature of dreams in students

    OpenAIRE

    Davidovsky Anatoly Grigorievich; Mezianaya Kira Nikolaevna; Yashin Konstantin Dmitrievich; Karaneuski Konstantin Mikhailovich; Dik Sergey Konstantinovich

    2015-01-01

    This study explored the use of different forms of the virtual world among students and the study of its influence on unconscious processes in students. The test group was comprised of 141 participants who were second to fifth year students at a technical university of Minsk city. We found that 38.3% of the participants spent more than 40 hours per work in the virtual world and 26.2% spent 25–39 hours per week. Moreover, 90.8% of the students engaged in computer games and game plots were prese...

  20. Repeated sleep restriction in rats leads to homeostatic and allostatic responses during recovery sleep.

    Science.gov (United States)

    Kim, Youngsoo; Laposky, Aaron D; Bergmann, Bernard M; Turek, Fred W

    2007-06-19

    Recent studies indicate that chronic sleep restriction can have negative consequences for brain function and peripheral physiology and can contribute to the allostatic load throughout the body. Interestingly, few studies have examined how the sleep-wake system itself responds to repeated sleep restriction. In this study, rats were subjected to a sleep-restriction protocol consisting of 20 h of sleep deprivation (SD) followed by a 4-h sleep opportunity each day for 5 consecutive days. In response to the first 20-h SD block on day 1, animals responded during the 4-h sleep opportunity with enhanced sleep intensity [i.e., nonrapid eye movement (NREM) delta power] and increased rapid eye movement sleep time compared with baseline. This sleep pattern is indicative of a homeostatic response to acute sleep loss. Remarkably, after the 20-h SD blocks on days 2-5, animals failed to exhibit a compensatory NREM delta power response during the 4-h sleep opportunities and failed to increase NREM and rapid eye movement sleep times, despite accumulating a sleep debt each consecutive day. After losing approximately 35 h of sleep over 5 days of sleep restriction, animals regained virtually none of their lost sleep, even during a full 3-day recovery period. These data demonstrate that the compensatory/homeostatic sleep response to acute SD does not generalize to conditions of chronic partial sleep loss. We propose that the change in sleep-wake regulation in the context of repeated sleep restriction reflects an allostatic process, and that the allostatic load produced by SD has direct effects on the sleep-wake regulatory system.

  1. [Current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry].

    Science.gov (United States)

    Wu, S S; Yu, J N; He, C H; Mu, H X; Wang, C; Zhang, Y; Zhang, C Y; Yu, S F; Li, X L

    2016-12-20

    Objective: To investigate the current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry. Methods: From August 2015 to March 2016, the investigation method of collecting the data of past occupational health examinations and measuring noise in working environment was used to enroll 8 672 male workers. Results: Of all workers, 11.6% were diagnosed with hearing loss. There were significant differences in the distribution of hearing impairment among workers exposed to noise at different ages, device types and types of work (χ(2)=17.80, 77.80 and 30.53, all P hearing loss in workers with noise exposure in refining and chemical industry. Conclusion: The level of noise exposure and working years with noise exposure are main influencing factors for hearing loss in workers with noise exposure in refining and chemical industry.

  2. Risk assessment of influence factors on occupational hearing loss in noise – exposed workers in typical metal industry

    OpenAIRE

    Farhadian Maryam; Aliabadi Mohsen; Shahidi Reza

    2014-01-01

    Background & Objectives : Worker exposure conditions such as noise level, exposure duration, use of hearing protection devices and health behaviors are commonly related to noise induced hearing loss. The objective of this study was risk assessment of influence factors on occupational hearing loss in noise exposed workers in typical noisy process . Methods : Information about occupational exposure of seventy workers employed in a noisy press workshop was gathered using the standard quest...

  3. Sleep and Obesity

    Directory of Open Access Journals (Sweden)

    Chenzhao Ding

    2018-03-01

    Full Text Available Rising global prevalence and incidence of obesity lead to increased cardiovascular-renal complications and cancers. Epidemiological studies reported a worldwide trend towards suboptimal sleep duration and poor sleep quality in parallel with this obesity epidemic. From rodents and human models, it is highly plausible that abnormalities in sleep, both quantity and quality, impact negatively on energy metabolism. While excess dietary intake and physical inactivity are the known drivers of the obesity epidemic, promotion of healthy sleep habits has emerged as a new target to combat obesity. In this light, present review focuses on the existing literature examining the relationship between sleep physiology and energy homeostasis. Notably, sleep dysregulation perturbs the metabolic milieu via alterations in hormones such as leptin and ghrelin, eating behavior, neuroendocrine and autonomic nervous systems. In addition, shift work and trans-meridian air travel may exert a negative influence on the hypothalamic-pituitary-adrenal axis and trigger circadian misalignment, leading to impaired glucose tolerance and increased fat accumulation. Amassing evidence has also suggested that uncoupling of the circadian clock can increase the risk of adverse metabolic health. Given the importance of sleep in maintaining energy homeostasis and that it is potentially modifiable, promoting good sleep hygiene may create new avenues for obesity prevention and treatment.

  4. Circadian adaptation to night shift work influences sleep, performance, mood and the autonomic modulation of the heart.

    Directory of Open Access Journals (Sweden)

    Philippe Boudreau

    Full Text Available Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV. Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laboratory for 48 h before and after a series of 7 consecutive night shifts in the field. The nighttime and daytime sleep periods were scheduled during the first and second laboratory visit, respectively. The subjects were considered "adapted" to night shifts if their peak salivary melatonin occurred during their daytime sleep period during the second visit. The sleep duration and quality were comparable between laboratory visits in the adapted group, whereas they were reduced during visit 2 in the non-adapted group. Reaction speed was higher at the end of the waking period during the second laboratory visit in the adapted compared to the non-adapted group. Sleep onset latency (SOL and subjective mood levels were significantly reduced and the LF∶HF ratio during daytime sleep was significantly increased in the non-adapted group compared to the adapted group. Circadian adaptation to night shift work led to better performance, alertness and mood levels, longer daytime sleep, and lower sympathetic dominance during daytime sleep. These results suggest that the degree of circadian adaptation to night shift work is associated to different health indices. Longitudinal studies are required to investigate long-term clinical implications of circadian misalignment to atypical work schedules.

  5. Circadian Adaptation to Night Shift Work Influences Sleep, Performance, Mood and the Autonomic Modulation of the Heart

    Science.gov (United States)

    Boudreau, Philippe; Dumont, Guy A.; Boivin, Diane B.

    2013-01-01

    Our aim was to investigate how circadian adaptation to night shift work affects psychomotor performance, sleep, subjective alertness and mood, melatonin levels, and heart rate variability (HRV). Fifteen healthy police officers on patrol working rotating shifts participated to a bright light intervention study with 2 participants studied under two conditions. The participants entered the laboratory for 48 h before and after a series of 7 consecutive night shifts in the field. The nighttime and daytime sleep periods were scheduled during the first and second laboratory visit, respectively. The subjects were considered “adapted” to night shifts if their peak salivary melatonin occurred during their daytime sleep period during the second visit. The sleep duration and quality were comparable between laboratory visits in the adapted group, whereas they were reduced during visit 2 in the non-adapted group. Reaction speed was higher at the end of the waking period during the second laboratory visit in the adapted compared to the non-adapted group. Sleep onset latency (SOL) and subjective mood levels were significantly reduced and the LF∶HF ratio during daytime sleep was significantly increased in the non-adapted group compared to the adapted group. Circadian adaptation to night shift work led to better performance, alertness and mood levels, longer daytime sleep, and lower sympathetic dominance during daytime sleep. These results suggest that the degree of circadian adaptation to night shift work is associated to different health indices. Longitudinal studies are required to investigate long-term clinical implications of circadian misalignment to atypical work schedules. PMID:23923024

  6. Influence of arousal threshold and depth of sleep on respiratory stability in man: analysis using a mathematical model.

    Science.gov (United States)

    Longobardo, G S; Evangelisti, C J; Cherniack, N S

    2009-12-01

    We examined the effect of arousals (shifts from sleep to wakefulness) on breathing during sleep using a mathematical model. The model consisted of a description of the fluid dynamics and mechanical properties of the upper airways and lungs, as well as a controller sensitive to arterial and brain changes in CO(2), changes in arterial oxygen, and a neural input, alertness. The body was divided into multiple gas store compartments connected by the circulation. Cardiac output was constant, and cerebral blood flows were sensitive to changes in O(2) and CO(2) levels. Arousal was considered to occur instantaneously when afferent respiratory chemical and neural stimulation reached a threshold value, while sleep occurred when stimulation fell below that value. In the case of rigid and nearly incompressible upper airways, lowering arousal threshold decreased the stability of breathing and led to the occurrence of repeated apnoeas. In more compressible upper airways, to maintain stability, increasing arousal thresholds and decreasing elasticity were linked approximately linearly, until at low elastances arousal thresholds had no effect on stability. Increased controller gain promoted instability. The architecture of apnoeas during unstable sleep changed with the arousal threshold and decreases in elasticity. With rigid airways, apnoeas were central. With lower elastances, apnoeas were mixed even with higher arousal thresholds. With very low elastances and still higher arousal thresholds, sleep consisted totally of obstructed apnoeas. Cycle lengths shortened as the sleep architecture changed from mixed apnoeas to total obstruction. Deeper sleep also tended to promote instability by increasing plant gain. These instabilities could be countered by arousal threshold increases which were tied to deeper sleep or accumulated aroused time, or by decreased controller gains.

  7. Dorsoventral and Proximodistal Hippocampal Processing Account for the Influences of Sleep and Context on Memory (Reconsolidation: A Connectionist Model

    Directory of Open Access Journals (Sweden)

    Justin Lines

    2017-01-01

    Full Text Available The context in which learning occurs is sufficient to reconsolidate stored memories and neuronal reactivation may be crucial to memory consolidation during sleep. The mechanisms of context-dependent and sleep-dependent memory (reconsolidation are unknown but involve the hippocampus. We simulated memory (reconsolidation using a connectionist model of the hippocampus that explicitly accounted for its dorsoventral organization and for CA1 proximodistal processing. Replicating human and rodent (reconsolidation studies yielded the following results. (1 Semantic overlap between memory items and extraneous learning was necessary to explain experimental data and depended crucially on the recurrent networks of dorsal but not ventral CA3. (2 Stimulus-free, sleep-induced internal reactivations of memory patterns produced heterogeneous recruitment of memory items and protected memories from subsequent interference. These simulations further suggested that the decrease in memory resilience when subjects were not allowed to sleep following learning was primarily due to extraneous learning. (3 Partial exposure to the learning context during simulated sleep (i.e., targeted memory reactivation uniformly increased memory item reactivation and enhanced subsequent recall. Altogether, these results show that the dorsoventral and proximodistal organization of the hippocampus may be important components of the neural mechanisms for context-based and sleep-based memory (reconsolidations.

  8. Rheumatoid arthritis and sleep quality.

    Science.gov (United States)

    Goes, Ana Claudia Janiszewski; Reis, Larissa Aparecida Busatto; Silva, Marilia Barreto G; Kahlow, Barbara Stadler; Skare, Thelma L

    Sleep disturbances are common in rheumatoid arthritis (RA) patients and contribute to loss of life quality. To study associations of sleep quality with pain, depression and disease activity in RA. This is a transversal observational study of 112 RA patients submitted to measurement of DAS-28, Epworth scale for daily sleepiness, index of sleep quality by Pittsburg index, risk of sleep apnea by the Berlin questionnaire and degree of depression by the CES-D (Center for Epidemiologic Studies Depression scale) questionnaire. We also collected epidemiological, clinical, serological and treatment data. Only 18.5% of RA patients had sleep of good quality. In univariate analysis a bad sleep measured by Pittsburg index was associated with daily doses of prednisone (p=0.03), DAS-28 (p=0.01), CES-D (p=0.0005) and showed a tendency to be associated with Berlin sleep apnea questionnaire (p=0.06). In multivariate analysis only depression (p=0.008) and Berlin sleep apnea questionnaire (p=0.004) kept this association. Most of RA patients do not have a good sleep quality. Depression and risk of sleep apnea are independently associated with sleep impairment. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

  9. Health Effects of Sleep Deprivation,

    Science.gov (United States)

    1990-06-01

    of an inordinate sleep loss (as hunger and thirst prevent us from going too long without food and water). Because of this, it takes great personal...drug-refractory depression. Neuropsychology 13:111-116, 1985. 82. Dowd PJ: Sleep deprivation effects on the vestibular habituation process. J Apply

  10. Influence of the airflow speed along transmission lines on the DC corona discharge loss, using finite element approach

    Energy Technology Data Exchange (ETDEWEB)

    Shemshadi, A.; Akbari, A. [Electric Department, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Niayesh, K. [Electric Engineering Department, Tehran University, Tehran (Iran, Islamic Republic of)

    2012-07-15

    Corona discharge is of great interest from the physical point of view and due to its numerous practical applications in industry and especially one of the most important sources of loss in the high voltage transmission lines. This paper provides guidelines for the amount of electric loss caused by corona phenomenon occurred around a DC high voltage wire placed between two flat plates and influence of wind speed rate on the amount of corona loss using COMSOL Multiphysics. So electric potential distribution patterns and charge density diffusion around the wire are studied in this article.

  11. The shift work and health research agenda: Considering changes in gut microbiota as a pathway linking shift work, sleep loss and circadian misalignment, and metabolic disease.

    Science.gov (United States)

    Reynolds, Amy C; Paterson, Jessica L; Ferguson, Sally A; Stanley, Dragana; Wright, Kenneth P; Dawson, Drew

    2017-08-01

    Prevalence and impact of metabolic disease is rising. In particular, overweight and obesity are at epidemic levels and are a leading health concern in the Western world. Shift work increases the risk of overweight and obesity, along with a number of additional metabolic diseases, including metabolic syndrome and type 2 diabetes (T2D). How shift work contributes to metabolic disease has not been fully elucidated. Short sleep duration is associated with metabolic disease and shift workers typically have shorter sleep durations. Short sleep durations have been shown to elicit a physiological stress response, and both physiological and psychological stress disrupt the healthy functioning of the intestinal gut microbiota. Recent findings have shown altered intestinal microbial communities and dysbiosis of the gut microbiota in circadian disrupted mice and jet lagged humans. We hypothesize that sleep and circadian disruption in humans alters the gut microbiota, contributing to an inflammatory state and metabolic disease associated with shift work. A research agenda for exploring the relationship between insufficient sleep, circadian misalignment and the gut microbiota is provided. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The influence of intermittent fasting on the circadian pattern of melatonin while controlling for caloric intake, energy expenditure, light exposure, and sleep schedules: A preliminary report.

    Science.gov (United States)

    Almeneessier, Aljohara S; Bahammam, Ahmed S; Sharif, Munir M; Bahammam, Salman A; Nashwan, Samar Z; Pandi Perumal, Seithikurippu R; Cardinali, Daniel P; Alzoghaibi, Mohammad

    2017-01-01

    We hypothesized that if we control for food composition, caloric intake, light exposure, sleep schedule, and exercise, intermittent fasting would not influence the circadian pattern of melatonin. Therefore, we designed this study to assess the effect of intermittent fasting on the circadian pattern of melatonin. Eight healthy volunteers with a mean age of 26.6 ± 4.9 years and body mass index of 23.7 ± 3.5 kg/m 2 reported to the Sleep Disorders Center (the laboratory) on four occasions: (1) adaptation, (2) 4 weeks before Ramadan while performing Islamic intermittent fasting for 1 week (fasting outside Ramadan [FOR]), (3) 1 week before Ramadan (nonfasting baseline [BL]), and (4) during the 2 nd week of Ramadan while fasting ( Ramadan ). The plasma levels of melatonin were measured using enzyme-linked immunoassays at 22:00, 02:00, 04:00, 06:00, and 11:00 h. The light exposure, meal composition, energy expenditure, and sleep schedules remained the same while the participants stayed at the laboratory. The melatonin levels followed the same circadian pattern during the three monitoring periods (BL, FOR, and Ramadan ). The peak melatonin level was at 02:00 h and the trough level was at 11:00 h in all studied periods. Lower melatonin levels at 22:00 h were found during fasting compared to BL. Cosinor analysis revealed no significant changes in the acrophase of melatonin levels. In this preliminary report, under controlled conditions of light exposure, meal composition, energy expenditure, and sleep-wake schedules, intermittent fasting has no significant influence on the circadian pattern of melatonin.

  13. Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

    International Nuclear Information System (INIS)

    Souza, Fabio Jose Fabricio de Barros; Evangelista, Anne Rosso; Silva, Juliana Veiga; Madeira, Kristian

    2016-01-01

    Objective: Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods: This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results: The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m 2 , and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm 3 greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions: Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients. (author)

  14. Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fabio Jose Fabricio de Barros; Evangelista, Anne Rosso; Silva, Juliana Veiga; Madeira, Kristian, E-mail: fsouzapneumo@hotmail.com [Universidade do Extremo Sul Catarinense (UNESC), Criciuma, SC (Brazil). Curso de Medicina; Perico, Gregory Vinicius [Unidade Radiologica Criciuma, SC (Brazil)

    2016-01-15

    Objective: Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods: This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results: The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m{sup 2} , and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm{sup 3} greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions: Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients. (author)

  15. Trigeminal induced arousals during human sleep.

    Science.gov (United States)

    Heiser, Clemens; Baja, Jan; Lenz, Franziska; Sommer, J Ulrich; Hörmann, Karl; Herr, Raphael M; Stuck, Boris A

    2015-05-01

    Arousals caused by external stimuli during human sleep have been studied for most of the sensorial systems. It could be shown that a pure nasal trigeminal stimulus leads to arousals during sleep. The frequency of arousals increases dependent on the stimulus concentration. The aim of the study was to evaluate the influence of different stimulus durations on arousal frequency during different sleep stages. Ten young healthy volunteers with 20 nights of polysomnography were included in the study. Pure trigeminal stimulation with both different concentrations of CO2 (0, 10, 20, 40% v/v) and different stimulus durations (1, 3, 5, and 10 s) were applied during different sleep stages to the volunteers using an olfactometer. The application was performed during different sleep stages (light sleep, deep sleep, REM sleep). The number of arousals increased with rising stimulus duration and stimulus concentration during each sleep stage. Trigeminal stimuli during sleep led to arousals in dose- and time-dependent manner.

  16. Abutment height influences the effect of platform switching on peri-implant marginal bone loss.

    Science.gov (United States)

    Galindo-Moreno, Pablo; León-Cano, Ana; Monje, Alberto; Ortega-Oller, Inmaculada; O'Valle, Francisco; Catena, Andrés

    2016-02-01

    The purpose was to radiographically analyze and compare the marginal bone loss (MBL) between implants with different mismatching distance and to study the influence of the prosthetic abutment height on the MBL in association with the related mismatching distances. This retrospective study included 108 patients in whom 228 implants were placed, 180 with diameter of 4.5 mm and 48 with diameter of 5 mm. All patients received OsseoSpeed™ implants with internal tapered conical connection (Denstply Implants). Different mismatching distances were obtained, given that all implants were loaded with the same uni-abutment type (Lilac; Denstply Implants). Data were gathered on age, gender, bone substratum, smoking habits, previous history of periodontitis, and prosthetic features. MBL was analyzed radiographically at 6 and 18 months post-loading. Mixed linear analysis of mesial and distal MBL values yielded significant effects of abutment, implant diameter, follow-up period, bone substratum, smoking, and abutment × time interaction. MBL was greater at 18 vs. 6 months, for short vs. long abutments, for grafted vs. pristine bone, for a heavier smoking habit, and for implants with a diameter of 5.0 vs. 4.5 mm. Greater mismatching does not minimize the MBL; abutment height, smoking habit, and bone substratum may play a role in the MBL over the short- and medium term. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. The Influence of Hearing Aid Use on Outcomes of Children With Mild Hearing Loss.

    Science.gov (United States)

    Walker, Elizabeth A; Holte, Lenore; McCreery, Ryan W; Spratford, Meredith; Page, Thomas; Moeller, Mary Pat

    2015-10-01

    This study examined the effects of consistent hearing aid (HA) use on outcomes in children with mild hearing loss (HL). Five- or 7-year-old children with mild HL were separated into 3 groups on the basis of patterns of daily HA use. Using analyses of variance, we compared outcomes between groups on speech and language tests and a speech perception in noise task. Regression models were used to investigate the influence of cumulative auditory experience (audibility, early intervention, HA use) on outcomes. Full-time HA users demonstrated significantly higher scores on vocabulary and grammar measures compared with nonusers. There were no significant differences between the 3 groups on articulation or speech perception measures. After controlling for the variance in age at confirmation of HL, level of audibility, and enrollment in early intervention, only amount of daily HA use was a significant predictor of grammar and vocabulary. The current results provide evidence that children's language development benefits from consistent HA use. Nonusers are at risk in areas such as vocabulary and grammar compared with other children with mild HL who wear HAs regularly. Service providers should work collaboratively to encourage consistent HA use.

  18. Loss of T cells influences sex differences in behavior and brain structure.

    Science.gov (United States)

    Rilett, Kelly C; Friedel, Miriam; Ellegood, Jacob; MacKenzie, Robyn N; Lerch, Jason P; Foster, Jane A

    2015-05-01

    Clinical and animal studies demonstrate that immune-brain communication influences behavior and brain function. Mice lacking T cell receptor β and δ chains were tested in the elevated plus maze, open field, and light-dark test and showed reduced anxiety-like behavior compared to wild type. Interestingly sex differences were observed in the behavioural phenotype of TCRβ-/-δ- mice. Specifically, female TCRβ-/-δ- mice spent more time in the light chamber compared to wild type females, whereas male TCRβ-/-δ- spent more time in the center of the open field compared to wild type males. In addition, TCRβ-/-δ- mice did not show sex differences in activity-related behaviors observed in WT mice. Ex vivo brain imaging (7 Tesla MRI) revealed volume changes in hippocampus, hypothalamus, amygdala, periaqueductal gray, and dorsal raphe and other brain regions between wild type and T cell receptor knockout mice. There was also a loss of sexual dimorphism in brain volume in the bed nucleus of the stria terminalis, normally the most sexually dimorphic region in the brain, in immune compromised mice. These data demonstrate the presence of T cells is important in the development of sex differences in CNS circuitry and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Keeping Older Adults with Vision Loss Safe: Chronic Conditions and Comorbidities that Influence Functional Mobility

    Science.gov (United States)

    Riddering, Anne T.

    2008-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans aged 60 and older. The loss of central vision from AMD can decrease visual acuity, contrast sensitivity, glare sensitivity, color discrimination, and the ability to adapt to changes in lighting conditions. Older adults with vision loss often have other chronic,…

  20. Studing the Influence of Six Main Industrial Losses on Overall Equipment Effectiveness in Cold Rolling Unit of Mobarakeh Steel Complex

    Directory of Open Access Journals (Sweden)

    seyed Akbar Nilipour Tabatabaei

    2011-03-01

    Full Text Available Overall Equipment Effectiveness (OEE is a key indicator and a basis for evaluating the effectiveness of equipments as well as assessing the effectiveness of the Total Productive Maintenance (TPM system. This indicator together with overall equipment performance can be used in production lines such as steel production. The aim of this article is to study the influence of six main industrial losses on the OEE indicator . For this purpose, the OEE has been calculated in the cold rolling production lines of Mobarakeh Steel Complex the gap between production lines and the global industrial standards has been studied the causes of production system inefficiency has been investigated and the effectiveness of TPM system, equipments' bottlenecks and the influence of the main industry losses on OEE have been studied. The findings imply that the influence of the variation of availability and performance rates on OEE is high, while the influence of the variation of quality rate on OEE is not considerable.

  1. Assessing sleep in adolescents through a better understanding of sleep physiology.

    Science.gov (United States)

    George, Nancy M; Davis, Jean E

    2013-06-01

    Adolescents need about nine hours of sleep per night, yet most teens get far less. Inadequate sleep has consequences not only for academic performance but also for mental and physical health; it has been linked to lowered resilience and an increased risk of cardiovascular and metabolic diseases. It's imperative that assessment of sleep become a routine part of adolescent health care. An understanding of sleep physiology is essential to helping nurses better assess and manage sleep deprivation in this population. Sleep assessment involves evaluating the three main aspects of sleep: amount, quality, and architecture. The authors provide an overview of sleep physiology, describe sleep changes that occur during adolescence, and discuss the influence of these changes on adolescent health. They also provide simple questions that nurses can use to assess sleep and risk factors for disrupted sleep, and discuss patient education and other interventions.

  2. Von Hippel-Lindau status influences phenotype of liver cancers arising from PTEN loss

    Directory of Open Access Journals (Sweden)

    Sendor AB

    2015-02-01

    Full Text Available Adam B Sendor,1 Kathryn E Hacker,1 Shufen Chen,1 Armando L Corona,1 Oishee Sen,1 Derek Y Chiang,1 Anna Snavely,1 Arlin B Rogers,2 Stephanie A Montgomery,1 W Kimryn Rathmell,1 Autumn J McRee11Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA; 2Section of Pathology, Department of Biomedical Sciences, Cummings School of Veterinary Medicine, Tufts University, Boston, MA, USABackground: PTEN loss contributes to the development of liver diseases including hepatic steatosis and both hepatocellular carcinoma (HCC and cholangiocarcinoma (CC. The factors that influence the penetrance of these conditions are unclear. We explored the influence of sustained hypoxia signaling through co-deletion of Pten and Vhl in a murine model.Methods: We used a CreER-linked Keratin 18 mouse model to conditionally delete Pten, Vhl or both in somatic cells of adult mice, evaluating the resultant tumors by histology and gene expression microarray. Existing sets of gene expression data for human HCC and CC were examined for pathways related to those observed in the murine tumors, and a cohort of human CC samples was evaluated for relationships between HIF-1α expression and clinical outcomes.Results: Both Pten deletion genotypes developed liver tumors, but with differing phenotypes. Pten deletion alone led to large hepatic tumors with widespread hepatosteatosis. Co-deletion of Pten and Vhl with the Keratin 18 promoter resulted in reduced steatosis and a reduced tumor burden that was characterized by a trabecular architecture similar to CC. Genes associated with hepatic steatosis were coordinately expressed in the human HCC dataset, while genes involved in hypoxia response were upregulated in tumors from the human CC dataset. HIF-1α expression and overall survival were examined in an independent cohort of human CC tumors with no statistical differences uncovered.Conclusion: Pten deletion in Keratin 18 expressing cells leads to

  3. Sleep education in college: a preliminary study.

    Science.gov (United States)

    Tsai, Ling-Ling; Li, Sheng-Ping

    2004-12-01

    In this study we evaluated the effect of a two-credit (100 min./week) "Sleep Management" course on the sleep patterns of college students as the course progressed over an 18-wk. semester. Curricular activity included lectures, group discussions, and practice of self-evaluation of sleep. Instead of giving the students the whole list of sleep hygiene at the outset of the course, each concept of sleep hygiene was introduced and discussed under related lecture topics. A total of 241 students (131 men and 110 women) took the course and kept 7-day sleep logs three times. Concurrently, sleep-log data were collected from 65 students (32 men and 33 women) who were not taking the course. Both groups showed similar varieties of academic backgrounds and characteristics of sleep patterns at the beginning. Similarly, their sleep patterns, namely, rise time, nighttime awakenings, time asleep, time in bed, sleep efficiency, and rise time regularity, changed over the semester. Women in both groups had more nighttime awakenings. In contrast, sleep quality was progressively better for the group in the course but not for the control group. Only women in the course decreased their nap time in the second and third months. Thus, the course of "Sleep Management" only had a mild and limited effect on sleep patterns. The course content needs refinement to maximize influence on students' sleep patterns and habits, particularly, on reduction of insufficient sleep and daytime sleepiness which are the highest ranking sleep problems among college students.

  4. Influence of Weight Loss, Body Composition, and Lifestyle Behaviors on Plasma Adipokines: A Randomized Weight Loss Trial in Older Men and Women with Symptomatic Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Gary D. Miller

    2012-01-01

    Full Text Available Objective. To investigate effects of weight loss on adipokines and health measures in obese older adults with symptomatic knee osteoarthritis. Methods. Participants were randomly assigned to either weight loss (WL (men: 12, women: 14 or weight stable (WS group (men: 12, women: 13. WL intervention included meal replacements and structured exercise training. Measurements of leptin, adiponectin, soluble leptin receptor, lifestyle behaviors, and body composition were collected at baseline and 6 months. Univariate analysis of covariance was performed on 6 month variables, and Spearman and partial correlations were made between variables. Results. Weight loss was 13.0% and 6.7% in WL for men and women, respectively. Women in WL had lower whole body and trunk fat than WS. The leptin : adiponectin ratio was lower for women in WL than WS at 6 months, with no group differences in adipokines for men. Leptin and free leptin index correlated with body fat in both genders at baseline. Interestingly, only women showed reductions in leptin (P<0.100 and correlations between the percentage change leptin and trunk fat and the percentage changes in free leptin index with total fat and trunk fat. Partial correlations between 6 month adipokines after adjustments for covariates and group/time period show potential multivariate influences. Conclusions. In the presence of an effective weight loss intervention in older obese adults, there are significant relationships between weight and fat loss and leptin in women, but not men, suggesting gender-specific features of adipokine metabolism in this age group.

  5. Healthy Sleep Habits

    Science.gov (United States)

    ... Sleep Apnea Testing CPAP Healthy Sleep Habits Healthy Sleep Habits Your behaviors during the day, and especially ... team at an AASM accredited sleep center . Quick Sleep Tips Follow these tips to establish healthy sleep ...

  6. Obstructive Sleep Apnea

    Medline Plus

    Full Text Available ... find out more. Obstructive Sleep Apnea (OSA) Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) is a ... find out more. Obstructive Sleep Apnea (OSA) Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) is a ...

  7. Obstructive Sleep Apnea

    Science.gov (United States)

    ... find out more. Obstructive Sleep Apnea (OSA) Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) is a ... find out more. Obstructive Sleep Apnea (OSA) Obstructive Sleep Apnea (OSA) Obstructive sleep apnea (OSA) is a ...

  8. Influences of viscous losses and end effects on liquid metal flow in electromagnetic pumps

    International Nuclear Information System (INIS)

    Kim, Hee Reyoung; Seo, Joon Ho; Hong, Sang Hee; Cho, Su won; Nam, Ho Yun; Cho, Man

    1996-01-01

    (E) produced by externally applied magnetic fields by three-phase winding currents. It is concluded that since the influences of the end effects in addition to viscous losses are extensive particularly in high-velocity operations of the EM pumps, it is necessary to find ways to suppress them, such as proper selection of the pump parameters and compensation of the end effects

  9. Sleep-Related Behaviors and Beliefs Associated With Race/Ethnicity in Women

    OpenAIRE

    Grandner, Michael A.; Patel, Nirav P.; Jean-Louis, Girardin; Jackson, Nicholas; Gehrman, Philip R.; Perlis, Michael L.; Gooneratne, Nalaka S.

    2013-01-01

    Explore how social factors influence sleep, especially sleep-related beliefs and behaviors. Sleep complaints, sleep hygiene behaviors, and beliefs about sleep were studied in 65 black/African American and white/European American women. Differences were found for snoring and discrepancy between sleep duration and need. Sleep behaviors differed across groups for napping, methods for coping with sleep difficulties, and nonsleep behaviors in bed. Beliefs also distinguished groups, with difference...

  10. Sleep deprivation: consequences for students.

    Science.gov (United States)

    Marhefka, Julie King

    2011-09-01

    During the adolescent years, a delayed pattern of the sleep-wake cycle occurs. Many parents and health care providers are not aware that once established, these poor sleep habits can continue into adulthood. Early school hours start a pattern of sleep loss that begins a cycle of daytime sleepiness, which may affect mood, behavior, and increase risk for accidents or injury. These sleep-deprived habits established in adolescence can often lead to problems during college years. Sleep hygiene can be initiated to help break the cycle, along with education and implementation of a strict regimen. Monitoring all adolescents and college-aged students for sleep insufficiency is imperative to improve both academic and emotional well-being. Copyright 2011, SLACK Incorporated.

  11. Sleep, sport, and the brain.

    Science.gov (United States)

    Halson, Shona L; Juliff, Laura E

    2017-01-01

    The recognition that sleep is one of the foundations of athlete performance is increasing both in the elite athlete arena as well as applied performance research. Sleep, as identified through sleep deprivation and sleep extension investigations, has a role in performance, illness, injury, metabolism, cognition, memory, learning, and mood. Elite athletes have been identified as having poorer quality and quantity of sleep in comparison to the general population. This is likely the result on training times, competition stress/anxiety, muscle soreness, caffeine use, and travel. Sleep, in particular slow wave sleep, provides a restorative function to the body to recover from prior wakefulness and fatigue by repairing processes and restoring energy. In addition, research in the general population is highlighting the importance of sleep on neurophysiology, cognitive function, and mood which may have implications for elite athlete performance. It is thus increased understanding of both the effects of sleep deprivation and potential mechanisms of influence on performance that may allow scientists and practitioners to positively influence sleep in athletes and ultimately maximize performances. © 2017 Elsevier B.V. All rights reserved.

  12. Sleep Apnea

    Science.gov (United States)

    Sleep apnea is a common disorder that causes your breathing to stop or get very shallow. Breathing ... an hour. The most common type is obstructive sleep apnea. It causes your airway to collapse or ...

  13. Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

    Science.gov (United States)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

    2017-10-01

    Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of

  14. Influences of early shift work on the diurnal cortisol rhythm, mood and sleep: within-subject variation in male airline pilots.

    Science.gov (United States)

    Bostock, Sophie; Steptoe, Andrew

    2013-04-01

    We aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. Pilots sampled saliva and completed subjective mood ratings in a logbook 6 times over the day on two consecutive early shift days, two late days and two rest days. Sampling was scheduled at waking, waking+30 m, waking+2.5 h, waking+8 h, waking+12 h and bedtime. Waking time, sleep duration, sleep quality and working hours were also recorded. Cortisol responses were analysed with repeated measures analysis of variance with shift condition (early, late, rest) and sample time (1-6) as within-subject factors. Early shifts were associated with a higher cortisol increase in response to awakening (CAR(i)), a greater total cortisol output over the day (AUC(G)) and a slower rate of decline over the day than late shifts or rest days. Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color.

    Science.gov (United States)

    Canton, Jillian L; Smith, Mark R; Choi, Ho-Sun; Eastman, Charmane I

    2009-07-17

    Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Subjects (blue-eyed n = 7; brown eyed n = 6) maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO). Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux). An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline). A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment.Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. The average phase delay of the DLMO was -1.3 +/- 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. A single 2-hour bright light pulse combined with a moderate delay of the sleep/dark episode

  16. Phase delaying the human circadian clock with a single light pulse and moderate delay of the sleep/dark episode: no influence of iris color

    Directory of Open Access Journals (Sweden)

    Choi Ho-Sun

    2009-07-01

    Full Text Available Abstract Background Light exposure in the late evening and nighttime and a delay of the sleep/dark episode can phase delay the circadian clock. This study assessed the size of the phase delay produced by a single light pulse combined with a moderate delay of the sleep/dark episode for one day. Because iris color or race has been reported to influence light-induced melatonin suppression, and we have recently reported racial differences in free-running circadian period and circadian phase shifting in response to light pulses, we also tested for differences in the magnitude of the phase delay in subjects with blue and brown irises. Methods Subjects (blue-eyed n = 7; brown eyed n = 6 maintained a regular sleep schedule for 1 week before coming to the laboratory for a baseline phase assessment, during which saliva was collected every 30 minutes to determine the time of the dim light melatonin onset (DLMO. Immediately following the baseline phase assessment, which ended 2 hours after baseline bedtime, subjects received a 2-hour bright light pulse (~4,000 lux. An 8-hour sleep episode followed the light pulse (i.e. was delayed 4 hours from baseline. A final phase assessment was conducted the subsequent night to determine the phase shift of the DLMO from the baseline to final phase assessment. Phase delays of the DLMO were compared in subjects with blue and brown irises. Iris color was also quantified from photographs using the three dimensions of red-green-blue color axes, as well as a lightness scale. These variables were correlated with phase shift of the DLMO, with the hypothesis that subjects with lighter irises would have larger phase delays. Results The average phase delay of the DLMO was -1.3 ± 0.6 h, with a maximum delay of ~2 hours, and was similar for subjects with blue and brown irises. There were no significant correlations between any of the iris color variables and the magnitude of the phase delay. Conclusion A single 2-hour bright light

  17. Effects of Meditation versus Music Listening on Perceived Stress, Mood, Sleep, and Quality of Life in Adults with Early Memory Loss: A Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Innes, Kim E; Selfe, Terry Kit; Khalsa, Dharma Singh; Kandati, Sahiti

    2016-04-08

    Older adults with subjective cognitive decline (SCD) are at increased risk not only for Alzheimer's disease, but for poor mental health, impaired sleep, and diminished quality of life (QOL), which in turn, contribute to further cognitive decline, highlighting the need for early intervention. In this randomized controlled trial, we assessed the effects of two 12-week relaxation programs, Kirtan Kriya Meditation (KK) and music listening (ML), on perceived stress, sleep, mood, and health-related QOL in older adults with SCD. Sixty community-dwelling older adults with SCD were randomized to a KK or ML program and asked to practice 12 minutes daily for 12 weeks, then at their discretion for the following 3 months. At baseline, 12 weeks, and 26 weeks, perceived stress, mood, psychological well-being, sleep quality, and health-related QOL were measured using well-validated instruments. Fifty-three participants (88%) completed the 6-month study. Participants in both groups showed significant improvement at 12 weeks in psychological well-being and in multiple domains of mood and sleep quality (p's≤0.05). Relative to ML, those assigned to KK showed greater gains in perceived stress, mood, psychological well-being, and QOL-Mental Health (p's≤0.09). Observed gains were sustained or improved at 6 months, with both groups showing marked and significant improvement in all outcomes. Changes were unrelated to treatment expectancies. Findings suggest that practice of a simple meditation or ML program may improve stress, mood, well-being, sleep, and QOL in adults with SCD, with benefits sustained at 6 months and gains that were particularly pronounced in the KK group.

  18. The influence of premature loss of temporary upper molars on permanent molars.

    Science.gov (United States)

    Cernei, E R; Maxim, Dana Cristiana; Zetu, Irina Nicoleta

    2015-01-01

    Premature loss of primary molars due to dental caries and their complications has been associated with space loss and eruptive difficulties, especially when the loss occurs early. The aim of our study was to determine the impact of premature loss of temporary upper molars upon the longitudinal axis of the first and second upper permanent molar. The study group included 64 patients 6-9 years old with premature loss of primary molars and a control group of 48 patients with intact temporary teeth. It was evaluated the angle between longitudinal axis of first and second upper permanent molars and occlusal plane. The sofware used is Easy Dent 4 Viewer®.The data were analyzed by using the Statistical Package for the Social Sciences (version 20.0; SPSS, Chicago, III). It was observed that premature loss of upper second deciduous molars modifies greater the vertical axis of the permanent molars than the premature loss of first upper primary molar. First upper primary molar loss cause an acceleration eruption of first premolar, which will produce a distal inclintion of the both permanent molars. The use of space maintainers after premature loss of the second upper temporary molar is a last solution in preventing tridimensional lesions in the dental arch and occlusion.

  19. The genome-wide landscape of DNA methylation and hydroxymethylation in response to sleep deprivation impacts on synaptic plasticity genes

    OpenAIRE

    Massart, R; Freyburger, M; Suderman, M; Paquet, J; El Helou, J; Belanger-Nelson, E; Rachalski, A; Koumar, O C; Carrier, J; Szyf, M; Mongrain, V

    2014-01-01

    Sleep is critical for normal brain function and mental health. However, the molecular mechanisms mediating the impact of sleep loss on both cognition and the sleep electroencephalogram remain mostly unknown. Acute sleep loss impacts brain gene expression broadly. These data contributed to current hypotheses regarding the role for sleep in metabolism, synaptic plasticity and neuroprotection. These changes in gene expression likely underlie increased sleep intensity following sleep deprivation ...

  20. Sleep-Related Behaviors and Beliefs Associated With Race/Ethnicity in Women

    Science.gov (United States)

    Grandner, Michael A.; Patel, Nirav P.; Jean-Louis, Girardin; Jackson, Nicholas; Gehrman, Philip R.; Perlis, Michael L.; Gooneratne, Nalaka S.

    2013-01-01

    Explore how social factors influence sleep, especially sleep-related beliefs and behaviors. Sleep complaints, sleep hygiene behaviors, and beliefs about sleep were studied in 65 black/African American and white/European American women. Differences were found for snoring and discrepancy between sleep duration and need. Sleep behaviors differed across groups for napping, methods for coping with sleep difficulties, and nonsleep behaviors in bed. Beliefs also distinguished groups, with differences in motivation for sleep and beliefs about sleep being important for health and functioning. These findings have important public health implications in terms of developing effective sleep education interventions that include consideration of cultural aspects. PMID:23862291

  1. Sleep in caregivers: what we know and what we need to learn.

    Science.gov (United States)

    McCurry, Susan M; Song, Yeonsu; Martin, Jennifer L

    2015-11-01

    The number of informal caregivers providing assistance to adults is increasing commensurate with our aging society. Sleep disturbances are prevalent in caregivers and associated with negative physical, medical, and functional outcomes. Here, we describe the predisposing, precipitating, and perpetuating factors contributing to the development of sleep problems in caregivers, and discuss three understudied caregiving populations that have clinical importance and unique circumstances influencing sleep quality and health. There is clear evidence supporting the interaction between sleep loss, caregiving stress, and vulnerability to chronic disease. Telehealth and telemedicine sleep interventions for caregivers combined with assistive technologies targeting care-receivers have potential to be more individualized, affordable, and widely accessible than traditional in-person insomnia treatment approaches. Limited data exist describing the etiology and treatment of sleep problems in caregivers of veterans, medical patients newly discharged from the hospital, and developmentally disabled adults. There is a growing literature describing the general determinants of sleep disturbances in caregivers, the health consequences of these disturbances, and intervention strategies for treating them. Identifying effective sleep treatments suited to more specialized caregiving situations and increasing intervention access will help caregivers continue to provide quality care while protecting their own health and well-being.

  2. Volition and Motivation's Influence on Weight Loss Maintenance in the Period Following an Intensive Lifestyle Intervention

    DEFF Research Database (Denmark)

    Elsborg, Peter

    The prevalence of overweight and obesity in the world is growing. Because obesity is associated with a number of serious lifestyle diseases such as hearth disease, a vast amount of research has been devoted to investigate how to assist weight loss, for example through behavioural weight loss...

  3. Temporal and energetic downtime losses and its influence on wind farm economics

    Energy Technology Data Exchange (ETDEWEB)

    Chaves-Schwinteck, P.; Moennich, K. [DEWI, Oldenburg (Germany)

    2013-02-15

    The work introduced here addresses the assessment of production losses of operating wind turbines. The discussion is based on a comparison of two different methodologies to estimate the energetic losses of wind turbines proposed by IEC on its Technical Specification 61400-26-2. (orig.)

  4. Influence of habitat and number of nestlings on partial brood loss in red-cockaded woodpeckers

    Science.gov (United States)

    James R. McCormick; Richard N. Conner; D. Brent Burt; Daniel Saenz

    2004-01-01

    Partial brood loss in red-cockaded woodpeckers (Picoides borealis) was studied during 2 breeding seasons in eastern Texas. The timing of partial brood loss, group size, number of initial nestlings, number of birds fledged, and habitat characteristics of the group's cavity-tree cluster were examined for 37 woodpecker groups in loblolly- (

  5. Magnetic field structure influence on primary electron cusp losses for micro-scale discharges

    International Nuclear Information System (INIS)

    Dankongkakul, Ben; Araki, Samuel J.; Wirz, Richard E.

    2014-01-01

    An experimental effort was used to examine the primary electron loss behavior for micro-scale (≲3 cm diameter) discharges. The experiment uses an electron flood gun source and an axially aligned arrangement of ring-cusps to guide the electrons to a downstream point cusp. Measurements of the electron current collected at the point cusp show an unexpectedly complex loss pattern with azimuthally periodic structures. Additionally, in contrast to conventional theory for cusp losses, the overall radii of the measured collection areas are over an order of magnitude larger than the electron gyroradius. Comparing these results to Monte Carlo particle tracking simulations and a simplified analytical analysis shows that azimuthal asymmetries of the magnetic field far upstream of the collection surface can substantially affect the electron loss structure and overall loss area

  6. The Effects of Total Sleep Deprivation and Recovery Sleep on Cognitive Performance and Brain Function

    National Research Council Canada - National Science Library

    Drummond, Sean P

    2004-01-01

    .... Even less is known about the cerebral effects of recovery sleep. The overarching objective of this study is to investigate the effects of 2 full nights of sleep loss and 2 full nights of recovery sleep on cognitive performance and brain function...

  7. The Effects of Total Sleep Deprivation and Recovery Sleep on Cognitive Performance and Brain Function

    National Research Council Canada - National Science Library

    Gillin, J

    2003-01-01

    ..... Even less is known about the cerebral effects of recovery sleep. The objective of this study is to investigate the effects of 2 full nights of sleep loss and 2 full nights of recovery sleep on cognitive performance and brain function...

  8. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    International Nuclear Information System (INIS)

    Han, Feng Hui; Mao, Yi Jun; Tan, Ji Jian

    2016-01-01

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets

  9. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Energy Technology Data Exchange (ETDEWEB)

    Han, Feng Hui; Mao, Yi Jun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an (China); Tan, Ji Jian [Dept. of Research and Development, Shenyang Blower Works Group Co., Ltd., Shenyang (China)

    2016-11-15

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets.

  10. Nocturnal levels of chemerin and progranulin in adolescents: influence of sex, body mass index, glucose metabolism and sleep.

    Science.gov (United States)

    Daxer, Johann; Herttrich, Theresa; Zhao, Ying Y; Vogel, Mandy; Hiemisch, Andreas; Scheuermann, Kathrin; Körner, Antje; Kratzsch, Jürgen; Kiess, Wieland; Quante, Mirja

    2017-01-01

    Adipokines have been implicated in obesity, insulin resistance and sleep regulation. However, the role of chemerin and progranulin, two recently described adipokines, in the context of sleep remains unclear. The aim of this study was to compare nocturnal serum chemerin and progranulin levels between overweight/obese and normal-weight adolescents and to assess variations by sex, across different sleep stages and in relation to glucose metabolism. The study sample included 34 overweight/obese and 32 normal-weight adolescents from secondary schools and the Leipzig Research Center for Civilization Diseases (LIFE) Child study cohort. We obtained longitudinal serum adipokine levels during in-laboratory polysomnography followed by an oral glucose tolerance test. Overweight/obese adolescents had significantly higher mean nocturnal serum chemerin area under the curve (AUC) levels (348.2±133.3 vs. 241.7±67.7 vs. ng/mL×h, pprogranulin AUC was found between the groups. However, when assessing sex-specific levels, serum progranulin AUC levels were ~30% higher in overweight/obese males compared to overweight/obese females. Of note, nocturnal serum chemerin and progranulin AUC did not exhibit a correlation with markers of glucose metabolism or sleep stages. Collectively, we report a sexual dimorphism in nocturnal progranulin and chemerin levels, which may help explain underlying differences in energy balance and body composition between males and females in the context of obesity.

  11. Sleep loss reduces the DNA-binding of BMAL1, CLOCK, and NPAS2 to specific clock genes in the mouse cerebral cortex.

    Directory of Open Access Journals (Sweden)

    Valérie Mongrain

    Full Text Available We have previously demonstrated that clock genes contribute to the homeostatic aspect of sleep regulation. Indeed, mutations in some clock genes modify the markers of sleep homeostasis and an increase in homeostatic sleep drive alters clock gene expression in the forebrain. Here, we investigate a possible mechanism by which sleep deprivation (SD could alter clock gene expression by quantifying DNA-binding of the core-clock transcription factors CLOCK, NPAS2, and BMAL1 to the cis-regulatory sequences of target clock genes in mice. Using chromatin immunoprecipitation (ChIP, we first showed that, as reported for the liver, DNA-binding of CLOCK and BMAL1 to target clock genes changes in function of time-of-day in the cerebral cortex. Tissue extracts were collected at ZT0 (light onset, -6, -12, and -18, and DNA enrichment of E-box or E'-box containing sequences was measured by qPCR. CLOCK and BMAL1 binding to Cry1, Dbp, Per1, and Per2 depended on time-of-day, with maximum values reached at around ZT6. We then observed that SD, performed between ZT0 and -6, significantly decreased DNA-binding of CLOCK and BMAL1 to Dbp, consistent with the observed decrease in Dbp mRNA levels after SD. The DNA-binding of NPAS2 and BMAL1 to Per2 was also decreased by SD, although SD is known to increase Per2 expression in the cortex. DNA-binding to Per1 and Cry1 was not affected by SD. Our results show that the sleep-wake history can affect the clock molecular machinery directly at the level of chromatin binding thereby altering the cortical expression of Dbp and Per2 and likely other targets. Although the precise dynamics of the relationship between DNA-binding and mRNA expression, especially for Per2, remains elusive, the results also suggest that part of the reported circadian changes in DNA-binding of core clock components in tissues peripheral to the suprachiasmatic nuclei could, in fact, be sleep-wake driven.

  12. Sleep loss reduces the DNA-binding of BMAL1, CLOCK, and NPAS2 to specific clock genes in the mouse cerebral cortex.

    Science.gov (United States)

    Mongrain, Valérie; La Spada, Francesco; Curie, Thomas; Franken, Paul

    2011-01-01

    We have previously demonstrated that clock genes contribute to the homeostatic aspect of sleep regulation. Indeed, mutations in some clock genes modify the markers of sleep homeostasis and an increase in homeostatic sleep drive alters clock gene expression in the forebrain. Here, we investigate a possible mechanism by which sleep deprivation (SD) could alter clock gene expression by quantifying DNA-binding of the core-clock transcription factors CLOCK, NPAS2, and BMAL1 to the cis-regulatory sequences of target clock genes in mice. Using chromatin immunoprecipitation (ChIP), we first showed that, as reported for the liver, DNA-binding of CLOCK and BMAL1 to target clock genes changes in function of time-of-day in the cerebral cortex. Tissue extracts were collected at ZT0 (light onset), -6, -12, and -18, and DNA enrichment of E-box or E'-box containing sequences was measured by qPCR. CLOCK and BMAL1 binding to Cry1, Dbp, Per1, and Per2 depended on time-of-day, with maximum values reached at around ZT6. We then observed that SD, performed between ZT0 and -6, significantly decreased DNA-binding of CLOCK and BMAL1 to Dbp, consistent with the observed decrease in Dbp mRNA levels after SD. The DNA-binding of NPAS2 and BMAL1 to Per2 was also decreased by SD, although SD is known to increase Per2 expression in the cortex. DNA-binding to Per1 and Cry1 was not affected by SD. Our results show that the sleep-wake history can affect the clock molecular machinery directly at the level of chromatin binding thereby altering the cortical expression of Dbp and Per2 and likely other targets. Although the precise dynamics of the relationship between DNA-binding and mRNA expression, especially for Per2, remains elusive, the results also suggest that part of the reported circadian changes in DNA-binding of core clock components in tissues peripheral to the suprachiasmatic nuclei could, in fact, be sleep-wake driven.

  13. Meeting Teen Sleep Needs Creatively

    Science.gov (United States)

    Wolfson, Amy R.; Carskadon, Mary A.

    2005-01-01

    Research on the sleep needs of adolescents and the influence of sleep on learning and behavior have captured the interest of school districts nationwide and in other countries as well. As a result, school officials are being urged to acknowledge the evidence and to adjust school schedules accordingly (e.g., to delay high school start times). The…

  14. The influence of hearing aids on the speech and language development of children with hearing loss.

    Science.gov (United States)

    Tomblin, J Bruce; Oleson, Jacob J; Ambrose, Sophie E; Walker, Elizabeth; Moeller, Mary Pat

    2014-05-01

    IMPORTANCE Hearing loss (HL) in children can be deleterious to their speech and language development. The standard of practice has been early provision of hearing aids (HAs) to moderate these effects; however, there have been few empirical studies evaluating the effectiveness of this practice on speech and language development among children with mild-to-severe HL. OBJECTIVE To investigate the contributions of aided hearing and duration of HA use to speech and language outcomes in children with mild-to-severe HL. DESIGN, SETTING, AND PARTICIPANTS An observational cross-sectional design was used to examine the association of aided hearing levels and length of HA use with levels of speech and language outcomes. One hundred eighty 3- and 5-year-old children with HL were recruited through records of Universal Newborn Hearing Screening and referrals from clinical service providers in the general community in 6 US states. INTERVENTIONS All but 4 children had been fitted with HAs, and measures of aided hearing and the duration of HA use were obtained. MAIN OUTCOMES AND MEASURES Standardized measures of speech and language ability were obtained. RESULTS Measures of the gain in hearing ability for speech provided by the HA were significantly correlated with levels of speech (ρ179 = 0.20; P = .008) and language: ρ155 = 0.21; P = .01) ability. These correlations were indicative of modest levels of association between aided hearing and speech and language outcomes. These benefits were found for children with mild and moderate-to-severe HL. In addition, the amount of benefit from aided hearing interacted with the duration of HA experience (Speech: F4,161 = 4.98; P < .001; Language: F4,138 = 2.91; P < .02). Longer duration of HA experience was most beneficial for children who had the best aided hearing. CONCLUSIONS AND RELEVANCE The degree of improved hearing provided by HAs was associated with better speech and language development in children

  15. Risk assessment of influence factors on occupational hearing loss in noise – exposed workers in typical metal industry

    Directory of Open Access Journals (Sweden)

    Farhadian Maryam

    2014-11-01

    Full Text Available Background & Objectives : Worker exposure conditions such as noise level, exposure duration, use of hearing protection devices and health behaviors are commonly related to noise induced hearing loss. The objective of this study was risk assessment of influence factors on occupational hearing loss in noise exposed workers in typical noisy process . Methods : Information about occupational exposure of seventy workers employed in a noisy press workshop was gathered using the standard questionnaire. Audiometery test was performed using the screening audiometer (Model-Mevox. Afterward, the collected data was analyzed by using the Cox model in SPSS software. Results : Based on results of the developed model, the job type and using status of HPD were most important features to induce hearing loss among workers. The risk of hearing loss among workers with the intermittent use of hearing protection was 3.1 times more than workers used their devices continuously. Relative risk of hearing loss among smoker workers compared with non-smoker was 1.1. Conclusion : The developed model could determine the effects of workers’ exposure conditions on risk of occupational hearing loss. This systematic approach can be considered as a helpful tool for determination the effectiveness of hearing conservation program and provide useful information for the managers and professionals in order to revise the existing health programs.

  16. A User Oriented Review of the Literature on the Effects of Sleep Loss, Work-Rest Schedules, and Recovery on Performance

    Science.gov (United States)

    1974-12-01

    Martin , 0. E. and Alluisi, E. A., "Human Performance as a Function of the Work-Rest Cycle: A Review of Selected Studies," National Academy.of Sciences...WilKinson, R. T., "One Stress on Top of Another," New So0eety, 12 JOly 1972, 72-75 52. Wilkinson, R. T., "Sleep Deprivation-Eight Questions," MRC

  17. Sleeping with technology: cognitive, affective, and technology usage predictors of sleep problems among college students.

    Science.gov (United States)

    Rosen, Larry; Carrier, Louis M; Miller, Aimee; Rokkum, Jeffrey; Ruiz, Abraham

    2016-03-01

    Sleep problems related to technology affect college students through several potential mechanisms including displacement of sleep due to technology use, executive functioning abilities, and the impact of emotional states related to stress and anxiety about technology availability. In the present study, cognitive and affective factors that influence technology usage were examined for their impact upon sleep problems. More than 700 US college students completed an online questionnaire addressing technology usage, anxiety/dependence, executive functioning, nighttime phone usage, bedtime phone location, and sleep problems. A path model controlling for background variables was tested using the data. The results showed that executive dysfunction directly predicted sleep problems as well as affected sleep problems through nighttime awakenings. In addition, anxiety/dependence increased daily smartphone usage and also increased nighttime awakenings, which, in turn, affected sleep problems. Thus, both the affective and cognitive factors that influence technology usage affected sleep problems. Copyright © 2016 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

  18. Influence of Inter-Intra Row Spacing on Yield Losses of Tomato ...

    African Journals Online (AJOL)

    losses of tomato growing under open field production with fresh market (Bishola) and processing ..... AVRDC. 2003. Asian Vegetable Research and Development Centre, Shanhua, Tainan, progress ... Australia national universities. 20: 1.

  19. Sleep deprivation suppresses aggression in Drosophila

    Science.gov (United States)

    Kayser, Matthew S; Mainwaring, Benjamin; Yue, Zhifeng; Sehgal, Amita

    2015-01-01

    Sleep disturbances negatively impact numerous functions and have been linked to aggression and violence. However, a clear effect of sleep deprivation on aggressive behaviors remains unclear. We find that acute sleep deprivation profoundly suppresses aggressive behaviors in the fruit fly, while other social behaviors are unaffected. This suppression is recovered following post-deprivation sleep rebound, and occurs regardless of the approach to achieve sleep loss. Genetic and pharmacologic approaches suggest octopamine signaling transmits changes in aggression upon sleep deprivation, and reduced aggression places sleep-deprived flies at a competitive disadvantage for obtaining a reproductive partner. These findings demonstrate an interaction between two phylogenetically conserved behaviors, and suggest that previous sleep experiences strongly modulate aggression with consequences for reproductive fitness. DOI: http://dx.doi.org/10.7554/eLife.07643.001 PMID:26216041

  20. TFAP2B influences the effect of dietary fat on weight loss under energy restriction

    DEFF Research Database (Denmark)

    Stocks, Tanja; Angquist, Lars; Banasik, Karina

    2012-01-01

    Numerous gene loci are related to single measures of body weight and shape. We investigated if 55 SNPs previously associated with BMI or waist measures, modify the effects of fat intake on weight loss and waist reduction under energy restriction.......Numerous gene loci are related to single measures of body weight and shape. We investigated if 55 SNPs previously associated with BMI or waist measures, modify the effects of fat intake on weight loss and waist reduction under energy restriction....

  1. Sleep Insufficiency, Sleep Health Problems and Performance in High School Students

    Directory of Open Access Journals (Sweden)

    Xue Ming

    2011-01-01

    Full Text Available A survey on sleep schedule, sleep health, school performance and school start times was conducted in 1,941 adolescents. A high level of early and circadian-disadvantaged sleep/wake schedules during weekdays was observed. Shorter sleep duration on weekdays was reported, especially in upper classmen. Complaints of inadequate sleep and sleepiness during weekdays, alarm clock use, and napping were prevalent. Night awakening and prolonged sleep onset were common and associated with poor school performance. Students with a sleep length of less than 7 hours on both weekdays and weekends exhibited poorer performance, while those who made up this sleep loss on weekends did not. The total number of poor sleep factors in an individual also correlated with poor school performance. Earlier school start times were associated with a perception of poor sleep quality, shorter sleep duration and more sleep health problems. We conclude that sleep inadequacies and sleep health problems were prevalent in this population, especially in those who started school earlier in the morning, and that these poor sleep factors were associated with school performance.

  2. The Influence of Water and Mineral Oil On Volumetric Losses in a Hydraulic Motor

    Directory of Open Access Journals (Sweden)

    Śliwiński Pawel

    2017-04-01

    Full Text Available In this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties are described and compared. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquids, including water. The sources of leaks in this motor are also characterized and described. On this basis, a mathematical model of volumetric losses and model of effective rotational speed have been developed and presented. The results of calculation of volumetric losses according to the model are compared with the results of experiment. It was found that the difference is not more than 20%. Furthermore, it has been demonstrated that this model well describes in both the volumetric losses in the motor supplied with water and oil. Experimental studies have shown that the volumetric losses in the motor supplied with water are even three times greater than the volumetric losses in the motor supplied with oil. It has been shown, that in a small constant stream of water the speed of the motor is reduced even by half in comparison of speed of motor supplied with the same stream of oil.

  3. translin is required for metabolic regulation of sleep

    OpenAIRE

    Murakami, Kazuma; Yurgel, Maria E.; Stahl, Bethany A.; Masek, Pavel; Mehta, Aradhana; Heidker, Rebecca; Bollinger, Wesley; Gingras, Robert M.; Kim, Young-Joon; Ja, William W.; Suter, Beat; DiAngelo, Justin R.; Keene, Alex C.

    2016-01-01

    Dysregulation of sleep or feeding has enormous health consequences. In humans, acute sleep loss is associated with increased appetite and insulin insensitivity, while chronically sleep-deprived individuals are more likely to develop obesity, metabolic syndrome, type II diabetes, and cardiovascular disease. Conversely, metabolic state potently modulates sleep and circadian behavior; yet, the molecular basis for sleep-metabolism interactions remains poorly understood. Here, we describe the iden...

  4. Losing Neutrality: The Neural Basis of Impaired Emotional Control without Sleep.

    Science.gov (United States)

    Simon, Eti Ben; Oren, Noga; Sharon, Haggai; Kirschner, Adi; Goldway, Noam; Okon-Singer, Hadas; Tauman, Rivi; Deweese, Menton M; Keil, Andreas; Hendler, Talma

    2015-09-23

    Sleep deprivation has been shown recently to alter emotional processing possibly associated with reduced frontal regulation. Such impairments can ultimately fail adaptive attempts to regulate emotional processing (also known as cognitive control of emotion), although this hypothesis has not been examined directly. Therefore, we explored the influence of sleep deprivation on the human brain using two different cognitive-emotional tasks, recorded using fMRI and EEG. Both tasks involved irrelevant emotional and neutral distractors presented during a competing cognitive challenge, thus creating a continuous demand for regulating emotional processing. Results reveal that, although participants showed enhanced limbic and electrophysiological reactions to emotional distractors regardless of their sleep state, they were specifically unable to ignore neutral distracting information after sleep deprivation. As a consequence, sleep deprivation resulted in similar processing of neutral and negative distractors, thus disabling accurate emotional discrimination. As expected, these findings were further associated with a decrease in prefrontal connectivity patterns in both EEG and fMRI signals, reflecting a profound decline in cognitive control of emotion. Notably, such a decline was associated with lower REM sleep amounts, supporting a role for REM sleep in overnight emotional processing. Altogether, our findings suggest that losing sleep alters emotional reactivity by lowering the threshold for emotional activation, leading to a maladaptive loss of emotional neutrality. Significance statement: Sleep loss is known as a robust modulator of emotional reactivity, leading to increased anxiety and stress elicited by seemingly minor triggers. In this work, we aimed to portray the neural basis of these emotional impairments and their possible association with frontal regulation of emotional processing, also known as cognitive control of emotion. Using specifically suited EEG and f

  5. Sleep Patterns of Naval Aviation Personnel Conducting Mine Hunting Operations

    National Research Council Canada - National Science Library

    Solberg, Bennett J

    2006-01-01

    Detailed research conducted over the past forty years has conclusively determined that varying degrees of sleep loss shifts in sleep cycle increased stress and even changes in time zone with respect...

  6. Mammalian sleep

    Science.gov (United States)

    Staunton, Hugh

    2005-05-01

    This review examines the biological background to the development of ideas on rapid eye movement sleep (REM sleep), so-called paradoxical sleep (PS), and its relation to dreaming. Aspects of the phenomenon which are discussed include physiological changes and their anatomical location, the effects of total and selective sleep deprivation in the human and animal, and REM sleep behavior disorder, the latter with its clinical manifestations in the human. Although dreaming also occurs in other sleep phases (non-REM or NREM sleep), in the human, there is a contingent relation between REM sleep and dreaming. Thus, REM is taken as a marker for dreaming and as REM is distributed ubiquitously throughout the mammalian class, it is suggested that other mammals also dream. It is suggested that the overall function of REM sleep/dreaming is more important than the content of the individual dream; its function is to place the dreamer protagonist/observer on the topographical world. This has importance for the developing infant who needs to develop a sense of self and separateness from the world which it requires to navigate and from which it is separated for long periods in sleep. Dreaming may also serve to maintain a sense of ‘I’ness or “self” in the adult, in whom a fragility of this faculty is revealed in neurological disorders.

  7. Sleep complaints and fatigue of airline pilots.

    Science.gov (United States)

    Reis, Cátia; Mestre, Catarina; Canhão, Helena; Gradwell, David; Paiva, Teresa

    2016-01-01

    This work aimed to determine daytime sleepiness and sleep complaints prevalence and the corresponding influence on perceived fatigue and to evaluate the influence of sociodemographic parameters and labour variables on sleep complaints, sleepiness and fatigue. A questionnaire was developed including socio-economic and labour issues and instruments, focused in sleep and fatigue. The response rate was 32% and the final sample had 435 pilots. The prevalence of sleep complaints was 34.9%, daytime sleepiness 59.3% and fatigue 90.6%. The high prevalence of sleep complaints, sleepiness and fatigue was disclosed in pilots, with those who fly short/medium having an added risk of fatigue.

  8. Sleep is not just for the brain: transcriptional responses to sleep in peripheral tissues.

    Science.gov (United States)

    Anafi, Ron C; Pellegrino, Renata; Shockley, Keith R; Romer, Micah; Tufik, Sergio; Pack, Allan I

    2013-05-30

    Many have assumed that the primary function of sleep is for the brain. We evaluated the molecular consequences of sleep and sleep deprivation outside the brain, in heart and lung. Using microarrays we compared gene expression in tissue from sleeping and sleep deprived mice euthanized at the same diurnal times. In each tissue, nearly two thousand genes demonstrated statistically significant differential expression as a function of sleep/wake behavioral state. To mitigate the influence of an artificial deprivation protocol, we identified a subset of these transcripts as specifically sleep-enhanced or sleep-repressed by requiring that their expression also change over the course of unperturbed sleep. 3% and 6% of the assayed transcripts showed "sleep specific" changes in the lung and heart respectively. Sleep specific transcripts in these tissues demonstrated highly significant overlap and shared temporal dynamics. Markers of cellular stress and the unfolded protein response were reduced during sleep in both tissues. These results mirror previous findings in brain. Sleep-enhanced pathways reflected the unique metabolic functions of each tissue. Transcripts related to carbohydrate and sulfur metabolic processes were enhanced by sleep in the lung, and collectively favor buffering from oxidative stress. DNA repair and protein metabolism annotations were significantly enriched among the sleep-enhanced transcripts in the heart. Our results also suggest that sleep may provide a Zeitgeber, or synchronizing cue, in the lung as a large cluster of transcripts demonstrated systematic changes in inter-animal variability as a function of both sleep duration and circadian time. Our data support the notion that the molecular consequences of sleep/wake behavioral state extend beyond the brain to include peripheral tissues. Sleep state induces a highly overlapping response in both heart and lung. We conclude that sleep enhances organ specific molecular functions and that it has a

  9. Influence of the CVCS Modelling on Results of the Loss of Offsite Power (LOOP) Safety Analysis for NPP Krsko

    International Nuclear Information System (INIS)

    Bencik, V.; Bajs, T.; Debrecin, N.

    2006-01-01

    A Loss of Offsite Power (LOOP) transient scenario is based on a complete loss of non-emergency AC power that results in the loss of all power to the plant auxiliaries, i.e., the Reactor Coolant Pumps (RCPs), condensate pumps, etc. An actual LOOP event would cause a loss of all feedwater, a loss of forced Reactor Coolant System (RCS) flow and a reactor trip within less than 2 seconds as a result of either loss of power to the rod cluster assembly gripper coils or any RCS flow trips. For safety analysis purposes the LOOP event is conservatively modelled as a Loss of Normal Feedwater (LONF) transient with a subsequent loss of offsite power as a result of a reactor trip. The reactor trip followed by RCP trip are delayed until a low-low Steam Generator (SG) level signal is reached. This is a more conservative scenario than the LOOP event because the least amount of SG secondary side water mass available for heat removal and the increased amount of the stored energy in the primary circuit at the time of the loss of RCS flow result. The standard LOOP safety analysis is aimed to demonstrate the natural circulation capability of the RCS to remove residual and decay heat from the core aided by Auxiliary Feedwater in the secondary system. In addition to this goal the presented work is aimed to resolve the potential safety issue resulting from the influence of the Chemical and Volume Control System (CVCS) operation during LOOP event for NPP Krsko. The potential safety concern for the LOOP analysis is that the loss of instrument air system may occur thus leading to the CVCS charging and letdown flow imbalance. A net RCS inventory addition may result with water solid pressurizer condition. Water discharge through the pressurizer relief and safety valves could lead to overpressurization of the Pressurizer Relief Tank (PRT) and rupture of the PRT rupture disks. Additional concern is that pressurizer relief and safety valves may fail to properly reseat when exposed to water relief

  10. Sleep and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Dongwoo Kang

    2015-06-01

    Full Text Available Sleep architecture and sleep patterns normally change with aging. In preclinical Alzheimer’s disease (AD, the accumulation of amyloid plaques begins 10 to 20 years before any cognitive symptoms progress. Soluble amyloid-β (Aβ is secreted during physiological synaptic activity. Since synaptic activity is correlated with sleep and awake state, a degree of Aβ fluctuates in a diurnal sleep pattern. In animal and human studies, a degree of sleep quality showed a significant correlation with brain levels of Aβ and a risk of AD. Conversely, Aβ aggregation would debilitate neuronal function in brain regions critical to sleep and wake promotion. This bidirectional relationship can be explained as positive feedback loop and associated factors that influence this relationship. In AD, the degree of sleep disturbances is much more severe compared with in the normal elderly. Further, Sundowning syndrome and a reduction of melatonin level cause a stressful neuropsychiatric symptoms and a disruption of physiological sleep rhythm, respectively. In AD patients, a correlation between sleep architectural modifications and learning performances has been reported. Moreover, executive function and emotional reactivity might be attenuated by sleep disturbances, too. However, sleep disturbance does not impact cognitive functions of all patients with AD. This could support an individual and potentially genetically determined susceptibility. Sleep disturbances have an important effect on patients and caregivers. It has a critical value to confirm and treat individuals with sleep disorders and to explore whether good quality of sleep in humans can decrease the progression of preclinical to symptomatic AD.

  11. Genetic background influences age-related decline in visual and nonvisual retinal responses, circadian rhythms, and sleep.

    Science.gov (United States)

    Banks, Gareth; Heise, Ines; Starbuck, Becky; Osborne, Tamzin; Wisby, Laura; Potter, Paul; Jackson, Ian J; Foster, Russell G; Peirson, Stuart N; Nolan, Patrick M

    2015-01-01

    The circadian system is entrained to the environmental light/dark cycle via retinal photoreceptors and regulates numerous aspects of physiology and behavior, including sleep. These processes are all key factors in healthy aging showing a gradual decline with age. Despite their importance, the exact mechanisms underlying this decline are yet to be fully understood. One of the most effective tools we have to understand the genetic factors underlying these processes are genetically inbred mouse strains. The most commonly used reference mouse strain is C57BL/6J, but recently, resources such as the International Knockout Mouse Consortium have started producing large numbers of mouse mutant lines on a pure genetic background, C57BL/6N. Considering the substantial genetic diversity between mouse strains we expect there to be phenotypic differences, including differential effects of aging, in these and other strains. Such differences need to be characterized not only to establish how different mouse strains may model the aging process but also to understand how genetic background might modify age-related phenotypes. To ascertain the effects of aging on sleep/wake behavior, circadian rhythms, and light input and whether these effects are mouse strain-dependent, we have screened C57BL/6J, C57BL/6N, C3H-HeH, and C3H-Pde6b+ mouse strains at 5 ages throughout their life span. Our data show that sleep, circadian, and light input parameters are all disrupted by the aging process. Moreover, we have cataloged a number of strain-specific aging effects, including the rate of cataract development, decline in the pupillary light response, and changes in sleep fragmentation and the proportion of time spent asleep. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Filter Influence on Rotor Losses in Coreless Axial Flux Permanent Magnet Machines

    Directory of Open Access Journals (Sweden)

    SANTIAGO, J.

    2013-02-01

    Full Text Available This paper investigates the eddy current losses induced in the rotor of coreless Axial-Flux machines. The calculation of eddy currents in the magnets requires the simulation of the inverter and the filter to obtain the harmonic content of the stator currents and FEM analysis of the magnets in the rotor. Due to the low inductance in coreless machines, the induced eddy current losses in the rotor remain lower than in traditional slotted machines. If only machine losses are considered, filters in DC/AC converters are not required in machines with wide airgaps as time harmonic losses in the rotor are very low.The harmonic content both from simulations and experimental results of a DC/AC converter are used to calculate the eddy currents in the rotor magnets. The properties of coreless machine topologies are investigated and some simplifications are proposed for time efficient 3D-FEM analysis. The time varying magnetic field can be considered constant over the magnets when the pole is divided in several magnets.The simplified FEM method to calculate eddy current losses is applicable to coreless machines with poles split into several magnets, although the conclusions are applicable to all coreless and slotless motors and generators.

  13. Influences of mach number and flow incidence on aerodynamic losses of steam turbine blade

    International Nuclear Information System (INIS)

    Yoo, Seok Jae; Ng, Wing Fai

    2000-01-01

    An experiment was conducted to investigate the aerodynamic losses of high pressure steam turbine nozzle (526A) subjected to a large range of incident angles (-34 .deg. to 26 .deg. ) and exit Mach numbers (0.6 and 1.15). Measurements included downstream pitot probe traverses, upstream total pressure, and endwall static pressures. Flow visualization techniques such as shadowgraph and color oil flow visualization were performed to complement the measured data. When the exit Mach number for nozzles increased from 0.9 to 1.1 the total pressure loss coefficient increased by a factor of 7 as compared to the total pressure losses measured at subsonic conditions (M 2 <0.9). For the range of incidence tested, the effect of flow incidence on the total pressure losses is less pronounced. Based on the shadowgraphs taken during the experiment, it's believed that the large increase in losses at transonic conditions is due to strong shock/ boundary layer interaction that may lead to flow separation on the blade suction surface

  14. 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....

  15. Sleep Can Eliminate List-Method Directed Forgetting

    Science.gov (United States)

    Abel, Magdalena; Bäuml, Karl-Heinz T.

    2013-01-01

    Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when…

  16. Sleep Paralysis and Hallucinosis

    Directory of Open Access Journals (Sweden)

    Gregory Stores

    1998-01-01

    Full Text Available Background: Sleep paralysis is one of the many conditions of which visual hallucinations can be a part but has received relatively little attention. It can be associated with other dramatic symptoms of a psychotic nature likely to cause diagnostic uncertainty. Methods and results: These points are illustrated by the case of a young man with a severe bipolar affective disorder who independently developed terrifying visual, auditory and somatic hallucinatory episodes at sleep onset, associated with a sense of evil influence and presence. The episodes were not obviously related to his psychiatric disorder. Past diagnoses included nightmares and night terrors. Review provided no convincing evidence of various other sleep disorders nor physical conditions in which hallucinatory experiences can occur. A diagnosis of predormital isolated sleep paralysis was made and appropriate treatment recommended. Conclusions: Sleep paralysis, common in the general population, can be associated with dramatic auxiliary symptoms suggestive of a psychotic state. Less common forms are either part of the narcolepsy syndrome or (rarely they are familial in type. Interestingly, sleep paralysis (especially breathing difficulty features prominently in the folklore of various countries.

  17. Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

    OpenAIRE

    Cappa, Christopher D.; Jathar, Shantanu H.; Kleeman, Michael J.; Docherty, Kenneth S.; Jimenez, Jose L.; Seinfeld, John H.; Wexler, Anthony S.

    2016-01-01

    The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA) formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the UCD/CIT regional air quality model using the statistical oxidation model (SOM) for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approa...

  18. Influence of soil water repellency on runoff and solute loss from New Zealand pasture

    Science.gov (United States)

    Jeyakumar, P.; Müller, K.; Deurer, M.; van den Dijssel, C.; Mason, K.; Green, S.; Clothier, B. E.

    2012-04-01

    Soil water repellency (SWR) has been reported in New Zealand, but knowledge on its importance for the country's economy and environment is limited. Our recent survey on the occurrence of SWR under pasture across the North Island of New Zealand showed that most soils exhibited SWR when dry independent of climate but influenced by the soil order. SWR is discussed as an important soil surface condition enhancing run-off and the transfer of fertilizers and pesticides from agricultural land into waterways. So far, the impact of SWR on run-off has rarely been measured. We developed a laboratory-scale run-off measurement apparatus (ROMA) to quantify directly the impact of SWR on run-off from undisturbed soil slabs. We compared the run-off resulting from the run-on of water with that resulting from an ethanol (30% v/v) solution, which is a fully-wetting liquid even in severely hydrophobic soils. Thus, the experiments with the ethanol solution can be understood as a proxy measure of the wetting-up behaviour of hydrophilic soils. We conducted ROMA run-off experiments with air-dried soil slabs (460 mm long x 190 mm wide x 50 mm deep) collected from pastoral sites, representing three major soil orders in the North Island: Recent Soil (Fluvisol), Gley Soil (Gleysol), and Organic Soil (Histosol), with water followed by the ethanol solution at a run-on rate of 60 mm/h. Bromide was applied at 80 kg KBr/ha prior to the water experiments to assess potential solute losses via run-off. The air-dried soils had a high degree and persistence of SWR (contact angles, 97, 98 and 104° , and potential water drop penetration times, 42, 54 and 231 min for the Fluvisol, Gleysol and Histosol, respectively). Under identical soil and experimental conditions, water generated run-off from all soils, but in the experiments with the ethanol solution, the entire ethanol solution infiltrated into the soils. The ranking of the run-off coefficients of the soils directly reflected their ranking in

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

    Directory of Open Access Journals (Sweden)

    Tae Won Kim

    2015-01-01

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

  20. Influence of Antenna Characteristics on Elevation Dependence of Building Penetration Loss for High Elevation Links

    Directory of Open Access Journals (Sweden)

    M. Kvicera

    2012-12-01

    Full Text Available Building penetration loss models presented in our previous paper [1] were valid for various scenarios, propagation conditions, frequency bands and hemispherical receiving antenna pointing towards zenith. These models had a significantly rising trend of penetration loss with increasing elevation angle of the link in common. In this paper we show that when working with non-isotropic terminal antennas, this trend relates primarily to the elevation trend of the corresponding reference level dependent on the receiving antenna radiation pattern. This is demonstrated by the results of single-input multiple-output (SIMO measurement trials performed at L-band in an office building and a brick building in the city of Prague. Further, based on the detailed analysis, a method to modify the elevation trend of a particular penetration loss model for different receiving antenna radiation patterns is derived and experimentally validated.

  1. Food loss rates at the food retail, influencing factors and reasons as a basis for waste prevention measures.

    Science.gov (United States)

    Lebersorger, S; Schneider, F

    2014-11-01

    This paper quantifies food loss rates for fruit & vegetables, dairy products and bread & pastry as well as donations to social services. In addition potential influencing factors and reasons for food losses are investigated in order to provide a basis for the development of waste prevention measures. Detailed data from 612 retail outlets all over Austria, which covered the period of one year, were analysed and sorting analyses of discarded food were carried out in a small sample of retail outlets. Food loss amounts to 1.3% of the sales of dairy products, 2.8% for bread & pastry and 4.2% for fruit & vegetables. Returned bread amounts to additional 9.7% of the sales of bread & pastry. The food loss rates are similar to the results of previous publications. At present, 7% of the food loss is donated to social services, 38% of retail outlets do not donate any articles at all. Food loss rates are declining with increasing sales areas, increasing numbers of purchases per year and increasing sales of the retail outlet, but explain only 33% or less of the variation of food loss rates. Large differences between retail outlets of comparable structure indicate potential for reduction. More than a quarter of discarded food articles did not show any flaws besides the expiration of the best before or sell-by date. Waste prevention approaches should focus on avoiding returns, transfer of best practices, information and education of employees and customers as well as strengthening the donation to social services. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Sleep disorders - overview

    Science.gov (United States)

    Insomnia; Narcolepsy; Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag ... excessive daytime sleepiness) Problems sticking to a regular sleep schedule (sleep rhythm problem) Unusual behaviors during sleep ( ...

  3. Central sleep apnea

    Science.gov (United States)

    Sleep apnea - central; Obesity - central sleep apnea; Cheyne-Stokes - central sleep apnea; Heart failure - central sleep apnea ... Central sleep apnea results when the brain temporarily stops sending signals to the muscles that control breathing. The condition ...

  4. Sleep Apnea (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Obstructive Sleep Apnea KidsHealth / For Parents / Obstructive Sleep Apnea What's ... How Is Sleep Apnea Treated? Print What Is Sleep Apnea? Brief pauses in breathing during sleep are ...

  5. Modelling Climate change influence on runoff and soil losses in a rainfed catchment with Mediterranean climate

    Science.gov (United States)

    Concepción Ramos, Maria; Martínez-Casasnovas, José A.

    2015-04-01

    The magnitude of erosion processes, widespread throughout the Mediterranean areas, may be enhanced due to changes in seasonal precipitation regimes and an increase of extreme events. The present research shows the results of possible effects of climate change on runoff and soil loss in a rainfed catchment located in the Barcelona province (NE Spain).In the study area, vines are the main land use, cultivated under the Penedès designation of origin. The present research shows the results of runoff and soil loss simulated using SWAT for a small basin with vines as main land use. Input data included detailed soil and land use maps, and daily climate data of the period 1998-2012. The analysis compared simulated results for years with different climatic conditions during that period and the average with predictions for the scenario 2020, 2050 and 2080 based on the HadCM3 GCM under A2 scenario and the trends observed in the area related to maximum rainfall intensity. The model was calibrated and validated using data recorded at different subbasins, using soil water and runoff samples. Taking into account the predicted changes in temperature and precipitation, the model simulated a decrease in soil loss associated with a decrease in runoff, mainly driven by an increase in evapotranspiration. However, the trend in soil losses varied when the changes in precipitation could balance the increase of evapotranspiration and also due to the increase of rainfall intensity. An increase in maximum rainfall intensity in spring and autumn (main rainy seasons) produced significant increases in soil loss: by up to 12% for the 2020 scenario and up to 57% for the 2050 scenario, although high differences may exists depending on rainfall characteristics. The research confirmed the difficulty of predicting future soil loss in this region, which has a very high climate inter-annual variability.

  6. White Matter Structure in Older Adults Moderates the Benefit of Sleep Spindles on Motor Memory Consolidation.

    Science.gov (United States)

    Mander, Bryce A; Zhu, Alyssa H; Lindquist, John R; Villeneuve, Sylvia; Rao, Vikram; Lu, Brandon; Saletin, Jared M; Ancoli-Israel, Sonia; Jagust, William J; Walker, Matthew P

    2017-11-29

    Sleep spindles promote the consolidation of motor skill memory in young adults. Older adults, however, exhibit impoverished sleep-dependent motor memory consolidation. The underlying pathophysiological mechanism(s) explaining why motor memory consolidation in older adults fails to benefit from sleep remains unclear. Here, we demonstrate that male and female older adults show impoverished overnight motor skill memory consolidation relative to young adults, with the extent of impairment being associated with the degree of reduced frontal fast sleep spindle density. The magnitude of the loss of frontal fast sleep spindles in older adults was predicted by the degree of reduced white matter integrity throughout multiple white matter tracts known to connect subcortical and cortical brain regions. We further demonstrate that the structural integrity of selective white matter fiber tracts, specifically within right posterior corona radiata, right tapetum, and bilateral corpus callosum, statistically moderates whether sleep spindles promoted overnight consolidation of motor skill memory. Therefore, white matter integrity within tracts known to connect cortical sensorimotor control regions dictates the functional influence of sleep spindles on motor skill memory consolidation in the elderly. The deterioration of white matter fiber tracts associated with human brain aging thus appears to be one pathophysiological mechanism influencing subcortical-cortical propagation of sleep spindles and their related memory benefits. SIGNIFICANCE STATEMENT Numerous studies have shown that sleep spindle expression is reduced and sleep-dependent motor memory is impaired in older adults. However, the mechanisms underlying these alterations have remained unknown. The present study reveals that age-related degeneration of white matter within select fiber tracts is associated with reduced sleep spindles in older adults. We further demonstrate that, within these same fiber tracts, the degree of

  7. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land.

    Science.gov (United States)

    Lieberman, Harris R; Tharion, William J; Shukitt-Hale, Barbara; Speckman, Karen L; Tulley, Richard

    2002-11-01

    When humans are acutely exposed to multiple stressors, cognitive performance is substantially degraded. Few practical strategies are available to sustain performance under such conditions. This study examined whether moderate doses of caffeine would reduce adverse effects of sleep deprivation and exposure to severe environmental and operational stress on cognitive performance. Volunteers were 68 U.S. Navy Sea-Air-Land (SEAL) trainees, randomly assigned to receive either 100, 200, or 300 mg caffeine or placebo in capsule form after 72 h of sleep deprivation and continuous exposure to other stressors. Cognitive tests administered included scanning visual vigilance, four-choice visual reaction time, a matching-to-sample working memory task and a repeated acquisition test of motor learning and memory. Mood state, marksmanship, and saliva caffeine were also assessed. Testing was conducted 1 and 8 h after treatment. Sleep deprivation and environmental stress adversely affected performance and mood. Caffeine, in a dose-dependent manner, mitigated many adverse effects of exposure to multiple stressors. Caffeine (200 and 300 mg) significantly improved visual vigilance, choice reaction time, repeated acquisition, self-reported fatigue and sleepiness with the greatest effects on tests of vigilance, reaction time, and alertness. Marksmanship, a task that requires fine motor coordination and steadiness, was not affected by caffeine. The greatest effects of caffeine were present 1 h post-administration, but significant effects persisted for 8 h. Even in the most adverse circumstances, moderate doses of caffeine can improve cognitive function, including vigilance, learning, memory, and mood state. When cognitive performance is critical and must be maintained during exposure to severe stress, administration of caffeine may provide a significant advantage. A dose of 200 mg appears to be optimal under such conditions.

  8. 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.

  9. Gain-loss-frame in outcome-interdependence : Does it influence equality or equity considerations?

    NARCIS (Netherlands)

    deDreu, CKW

    1996-01-01

    Research suggests that framing outcomes as gains produces stronger concern for distributive justice than framing outcomes as losses. Unfortunately, however, this prior research manipulated own and other's outcomes only (and not own and other's input). Hence, it remained unclear whether framing

  10. Influence of Inter-Intra Row Spacing on Yield Losses of Tomato ...

    African Journals Online (AJOL)

    Data on major yield loss agents such as, blossom end rot, decay, insect, disease, sunburn, crack, catface and others minor disorders were collected; as well as total yield, percent of marketable and unmarketable fruit yield parameters were analyzed. Results of the study showed that inter-intra row spacing and cultivar had a ...

  11. Influence of cable losses on the economic analysis of efficient and sustainable electrical equipment

    International Nuclear Information System (INIS)

    Lobão, J.A.; Devezas, T.; Catalão, J.P.S.

    2014-01-01

    Increasing energy needs are accompanied by environmental responsibilities, since nowadays electricity companies operate in a competitive and sustainable energy framework. In this context, any proposal for action on energy efficiency becomes important for consumers to minimize operational costs. In electrical installations, electricity consumption can be decreased by reducing losses in the cables, associated with the overall efficiency of the equipment, allowing a better use of the installed power. The losses must be analysed in conjunction with all loads that contribute to the currents in the sections of an electrical installation. When replacing equipment in output distribution boxes with more efficient ones, the current in those sections is reduced in association with the decrease in power losses. This decrease, often forgotten, is taken into account in this work for the economic analysis of efficiency and sustainable electrical equipment. This paper presents a new software application that compares and chooses the best investment in the acquisition of electrical equipment. Simulation results obtained with the new software application are provided and are then validated with experimental results from a real electrical installation. - Highlights: • Any proposal for action on energy efficiency is important for consumers. • Electricity consumption can be decreased by reducing losses in the cables. • A new software application that compares and chooses the best investment is provided. • The economic analysis of efficiency and sustainable electrical equipment is carried out. • Simulation results are validated with experimental results from a real electrical installation

  12. NITROGEN LOSS FROM SMALL WATERSHEDS IN THE OREGON CASCADES: A STUDY OF FOREST SUCCESSION INFLUENCE

    Science.gov (United States)

    Traditional biogeochemical theory suggests that biotic N limitation (N demand by plants and soil microorganisms) controls ecosystem nitrogen (N) losses, and that stream N export should increase with successional age. I am examining patterns of inorganic and organic N export from...

  13. SYNTHETIC AGB EVOLUTION .3. THE INFLUENCE OF DIFFERENT MASS-LOSS LAWS

    NARCIS (Netherlands)

    GROENEWEGEN, MAT; DEJONG, T

    In Paper I of this series we presented a model to calculate in a synthetic way the evolution of thermal-pulsing AGB stars. The model was applied to the LMC and values were derived for the minimum core mass for third dredge-up and the dredge-up efficiency. In Paper I mass loss on the AGB was

  14. North-south differences in Chinese agricultural losses due to climate-change-influenced droughts

    Science.gov (United States)

    Qiang, Zhang; Lanying, Han; Jingjing, Lin; Qingyan, Cheng

    2018-01-01

    One of the effects of global climate change is increase in the frequency and severity of drought, which strongly affects the Chinese agricultural production. In order to cope these changes more effectively, it is important to document and analyze the agricultural losses caused by drought. We collected and analyzed conventional meteorological data and agricultural statistics data, in order to outline trends in drought occurrence and decline in agricultural yield. Data were assembled for the period 1960-2010. The study pays particular attention to regional differences between northern and southern China. Our results show the drought-caused agricultural loss rates (DCALR) in China have increased by approximately 0.5% per decade in the past 50 years. The study area in this paper is for the whole of the People's Republic of China, minus the Qinghai-Tibetan Plateau; when we analyzed regional differences, we found that losses increased by approximately 0.6% per decade in northern China, close to twice the increase in southern China. Moreover, drought risks and agricultural losses are rising faster in northern China. Our results also indicate that the agriculture in northern China is more sensitive to changes in precipitation, whereas the agriculture in southern China is more sensitive to temperature changes.

  15. The influence of loss and gain of body mass on ovarian activity in ...

    African Journals Online (AJOL)

    Ovarian activity was studied in 36 dry, Bos taurus cows fed to achieve different rates of body mass loss and gain in a 2 x 2 factorial experiment. Cows were fed hay to supply either 70% (Treatments 1, 2) or 40% (Treatments. 3,4) of their ME requirements for maintenance until they became anoestrus. Following a 90-day ...

  16. Economic losses from US hurricanes consistent with an influence from climate change

    NARCIS (Netherlands)

    Estrada Porrua, F.; Botzen, W.J.W.; Tol, R.S.J.

    2015-01-01

    Warming of the climate system and its impacts on biophysical and human systems have been widely documented. The frequency and intensity of extreme weather events have also changed, but the observed increases in natural disaster losses are often thought to result solely from societal change, such as

  17. Influence of diurnal variations in stream temperature on streamflow loss and groundwater recharge

    Science.gov (United States)

    Constantz, Jim; Thomas, Carole L.; Zellweger, Gary W.

    1994-01-01

    We demonstrate that for losing reaches with significant diurnal variations in stream temperature, the effect of stream temperature on streambed seepage is a major factor contributing to reduced afternoon streamflows. An explanation is based on the effect of stream temperature on the hydraulic conductivity of the streambed, which can be expected to double in the 0° to 25°C temperature range. Results are presented for field experiments in which stream discharge and temperature were continuously measured for several days over losing reaches at St. Kevin Gulch, Colorado, and Tijeras Arroyo, New Mexico. At St. Kevin Gulch in July 1991, the diurnal stream temperature in the 160-m study reach ranged from about 4° to 18°C, discharges ranged from 10 to 18 L/s, and streamflow loss in the study reach ranged from 2.7 to 3.7 L/s. On the basis of measured stream temperature variations, the predicted change in conductivity was about 38%; the measured change in stream loss was about 26%, suggesting that streambed temperature varied less than the stream temperature. At Tijeras Arroyo in May 1992, diurnal stream temperature in the 655-m study reach ranged from about 10° to 25°C and discharge ranged from 25 to 55 L/s. Streamflow loss was converted to infiltration rates by factoring in the changing stream reach surface area and streamflow losses due to evaporation rates as measured in a hemispherical evaporation chamber. Infiltration rates ranged from about 0.7 to 2.0 m/d, depending on time and location. Based on measured stream temperature variations, the predicted change in conductivity was 29%; the measured change in infiltration was also about 27%. This suggests that high infiltration rates cause rapid convection of heat to the streambed. Evapotranspiration losses were estimated for the reach and adjacent flood plain within the arroyo. On the basis of these estimates, only about 5% of flow loss was consumed via stream evaporation and stream-side evapotranspiration

  18. Hydro-pneumatic accumulators for vehicles kinetic energy storage: Influence of gas compressibility and thermal losses on storage capability

    International Nuclear Information System (INIS)

    Puddu, Pierpaolo; Paderi, Maurizio

    2013-01-01

    In this work the differences between the thermodynamic behaviour of real and ideal gases are analysed to determine their influence on the processes of compression and expansion of a gas-charged accumulator. The behaviour of real gas has a significant influence on the size of accumulators used for Kinetic Energy Recovery of vehicles. In particular, it is underscored that the accumulator's design, based on ideal gas behaviour, provides undersized accumulators and therefore makes impossible the complete energy recovery for Hydraulic Energy Storage Systems (HES). The analysis of the thermodynamic properties of gases has shown that the main differences between ideal and real behaviour are due to gas compressibility. A mathematical model of a gas-charged accumulator is developed in order to analyse its real behaviour in presence of irreversible heat transfer and viscous losses. The simulation process of charging and discharging of a hydro-pneumatic accumulator, makes it clear that hydrodynamic and thermal losses are responsible for the characteristic hysteresis cycle on the p–V diagram. Different gases are tested as charged fluid of a hydro-pneumatic accumulator to simulate cyclic processes of charge and discharge. Results show different characteristics in terms of volumetric gas properties, thermal time-constant and thermal efficiency of the accumulator. - Highlights: • A dynamic model of a gas charged accumulator was developed. • Gas compressibility significantly influences the size of high-pressure accumulators. • A hysteresis loop is indicative of the thermal energy losses. • Loss increases with increasing the period of the cyclic process. • Thermal time constant is different from compression to expansion

  19. Sleep and Premenstrual Syndrome

    Science.gov (United States)

    Jehan, Shazia; Auguste, Evan; Hussain, Mahjabeen; Pandi-Perumal, Seithikurippu R.; Brzezinski, Amon; Gupta, Ravi; Attarian, Hrayr; Jean-Louis, Giradin; McFarlane, Samy I.

    2016-01-01

    The etiology of premenstrual syndrome (PMS) is unknown; it may be due to the normal effect of hormones during the menstrual cycle as it occurs in the late luteal phase of the menstrual cycle.PMS affects women of childbearing age and remits with the onset of menstruation. The menstrual phase is known to influence stage 2 and REM sleep in women, irrespective of premenstrual dysphoric disorder (PMDD). Women with PMDD showed a decreased response to melatonin in their luteal phase as compared to the follicular phase of the menstrual cycle. However, melatonin duration or timing of offset in the morning has not been reported to correlate with the mood. Rather, improvement in mood-related symptoms of PMDD has been found to be influenced by sleep deprivation, be it sleep restrictions in early or late night. Sleep disturbance and decreased melatonin secretions due to hormonal fluctuations during the luteal phase of the menstrual cycle could explain the sleep complaints of PMDD. PMID:28239684

  20. Impact of menstrual cycle phase on endocrine effects of partial sleep restriction in healthy women.

    Science.gov (United States)

    LeRoux, Amanda; Wright, Lisa; Perrot, Tara; Rusak, Benjamin

    2014-11-01

    There is extensive evidence that sleep restriction alters endocrine function in healthy young men, increasing afternoon cortisol levels and modifying levels of other hormones that regulate metabolism. Recent studies have confirmed these effects in young women, but have not investigated whether menstrual cycle phase influences these responses. The effects on cortisol levels of limiting sleep to 3h for one night were assessed in two groups of women at different points in their menstrual cycles: mid-follicular and mid-luteal. Eighteen healthy, young women, not taking oral contraceptives (age: 21.8±0.53; BMI: 22.5±0.58 [mean±SEM]), were studied. Baseline sleep durations, eating habits and menstrual cycles were monitored. Salivary samples were collected at six times of day (08:00, 08:30, 11:00, 14:00, 17:00, 20:00) during two consecutive days: first after a 10h overnight sleep opportunity (Baseline) and then after a night with a 3h sleep opportunity (Post-sleep restriction). All were awakened at the same time of day. Women in the follicular phase showed a significant decrease (p=0.004) in their cortisol awakening responses (CAR) after sleep restriction and a sustained elevation in afternoon/evening cortisol levels (p=0.008), as has been reported for men. Women in the luteal phase showed neither a depressed CAR, nor an increase in afternoon/evening cortisol levels. Secondary analyses examined the impact of sleep restriction on self-reported hunger and mood. Menstrual cycle phase dramatically altered the cortisol responses of healthy, young women to a single night of sleep restriction, implicating effects of spontaneous changes in endocrine status on adrenal responses to sleep loss. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Sleep in thyrotoxicosis

    Directory of Open Access Journals (Sweden)

    G R Sridhar

    2011-01-01

    Full Text Available Objective: Pattern of sleep in hyperthyroid state / thyrotoxicosis has not been systematically studied. It is being characterized as poor without further elaboration. We analyzed the pattern of sleep in a large sample of individuals with thyrotoxicosis who came to our endocrine center in southern India. Materials and Methods: We identified individuals with the diagnosis of ′thyrotoxicosis′ from our electronic medical record database, and evaluated clinical parameters and pattern of their sleep: difficulty in falling asleep (DFA, difficulty in maintaining sleep (DMS, excess daytime sleepiness. In the first phase, univariate analysis with logistic regression was performed. Multivariate logistic regression was performed in the next phase on variables with a P-value < 0.1: these were considered as potential categories/ variables. Results: In model response variable with DFA, multivariate logistic regression predicted that subjects with abnormal appetite (more 1.7 or less 2.2, change in bowel motion (loose 1.5 or constipation 2.8, in mood (easy loss of temper 3.4, change of voice -- hoarse 7.4 or moderately hoarse 3.1, tended to have higher chances of difficulty in falling asleep (DFA. Patients with tremor (yes = 5.4 had greater likelihood of difficulty in maintaining sleep (DMS. Conclusions: Individuals with hyperthyroidism/thyrotoxicosis principally had difficulty in falling asleep DFA, which was related to hyperkinetic features.

  2. Obstructive sleep apnea

    DEFF Research Database (Denmark)

    Jennum, Poul; Tønnesen, Philip; Ibsen, Rikke

    2017-01-01

    OBJECTIVE: Most studies have used cardiovascular and cerebrovascular disease (CVD) end-points to measure the effect of continuous positive airway pressure (CPAP), but pre-diagnostic morbidities involve a range of comorbidities that may influence the consequences of obstructive sleep apnea (OSA). We...

  3. Transepidermal water loss in cats: comparison of three differently clipped sites to assess the influence of hair coat on transepidermal water loss values.

    Science.gov (United States)

    Momota, Yutaka; Shimada, Kenichiroh; Takami, Akina; Akaogi, Harumi; Takasaki, Mariko; Mimura, Kana; Azakami, Daigo; Ishioka, Katsumi; Nakamura, Yuka; Sako, Toshinori

    2013-08-01

    The measurement of transepidermal water loss (TEWL) is one of the parameters that can be used to assess skin barrier function. The variability and reliability of TEWL measurements in dogs have been controversial, and the hair coat has been considered as one of the factors that may cause variation of TEWL values. The aims of the study were to establish a suitable procedure for measuring feline TEWL, to evaluate the influence of hair coat on TEWL measurements and to assess variations of TEWL at different anatomical sites. Transepidermal water loss was measured using a closed-chamber evaporimeter, the VapoMeter(®). We compared three adjacent sites in the groin area of 10 clinically normal, domestic short hair cats. One site was unclipped, the second was trimmed with scissors and the third was shaved using electric clippers. Values of TEWL were obtained for 48 h after trimming with scissors and clippers. Five sites were clipped (upper back, lumbar back, lateral thigh, axillae and groin), and the TEWL was measured. The mean and SD of TEWL values of the clipper-trimmed site were the smallest, followed in order by the site trimmed with scissors and the unclipped site. The TEWL values were statistically constant in the clipper-trimmed site, while the values in the unclipped sites were not. There was no statistically significant difference in TEWL values between all of the anatomical sites except for the axillae. Hair clipping of sites with electric clippers is recommended for TEWL measurement in cats. © 2013 ESVD and ACVD.

  4. [The importance of sleep in the mental health].

    Science.gov (United States)

    Hashizume, Yuji

    2014-02-01

    Japanese average sleeping time is decreasing year by year. The National Sleep Foundation of United States of America released that Japan reports the least amount of sleep. Japanese reports sleeping about 30 to 40 minutes less on workdays than those in the other countries surveyed, averaging 6 hours 22 minutes of sleep. There are many reports that insomnia has been suggested to cause depression and other mental disorders. And epidemiological evidence supports a link between sleep loss and obesity. Obesity is one of risk factors of obstructive sleep apnea syndrome which causes cognitive dysfunction, mood disorders and so on. Sleep loss and sleep insufficiency can cause mental disorders and be impaired cognitive function and performance.

  5. [Influence of nasal continuous positive airway pressure on response to exercise in patients with obstructive sleep apnea syndrome].

    Science.gov (United States)

    Przybyłowski, Tadeusz; Bielicki, Piotr; Kumor, Marta; Hildebrand, Katarzyna; Maskey-Warzechowska, Marta; Wiwała, Joanna; Kościuch, Justyna; Korczyński, Piotr; Chazan, Ryszarda

    2006-01-01

    Obstructive sleep apnea syndrome (OSAS) patients are at risk of cardiovascular complications. The aim of this study was to assess the effect of treatment with continuous positive airway pressure (CPAP) on the response to symptom limited exercise test. twenty nine OSAS patients (1 F, 28 M), mean age 50.7+/-9.7 yrs with body mass index of 32.6+/-4.5 kg/m2 participated in the study. OSAS was diagnosed by overnight polysomnography. Incremental cardiopulmonary exercise test (CPET) on a treadmill was performed twice: before and after 2-3 weeks of regular treatment with CPAP. mean apnea + hypopnea index (AHI) before therapy was 57.6+/-12 h(-1). CPAP treatment did not change peak oxygen consumption (VO2max) (38.3+/-9.0 vs. 38.9+/-6.9 mlO2/kg/min, p=ns) or peak heart rate (153.4+/-21 min- vs. 155.5+/-22 min(-1), p=ns). There were no significant changes in ventilation or gas exchange variables. However, a decrease in peak systolic blood pressure from 194.5+/-24 mmHg to 186.7+/-27.9 mmHg (prate (at 1st minute and minutes 3 - 6) and mean arterial pressure (MAP) (minutes 4-7) with CPAP treatment was observed. Significant correlations between VO2max and AHI (r=-0,38, p<0,05); MAP at peak exercise and: AHI, mean oxygen saturation (SaO2) during sleep, minutes of sleep with SaO2<90% (T90); MAP at recovery (minutes 3-8) and T90 before CPAP treatment were also noted. OSAS patients are not limited on exercise. Treatment with nasal CPAP attenuates circulatory response to incremental exercise on a treadmill.

  6. Auditory development in early amplified children: factors influencing auditory-based communication outcomes in children with hearing loss.

    Science.gov (United States)

    Sininger, Yvonne S; Grimes, Alison; Christensen, Elizabeth

    2010-04-01

    The purpose of this study was to determine the influence of selected predictive factors, primarily age at fitting of amplification and degree of hearing loss, on auditory-based outcomes in young children with bilateral sensorineural hearing loss. Forty-four infants and toddlers, first identified with mild to profound bilateral hearing loss, who were being fitted with amplification were enrolled in the study and followed longitudinally. Subjects were otherwise typically developing with no evidence of cognitive, motor, or visual impairment. A variety of subject factors were measured or documented and used as predictor variables, including age at fitting of amplification, degree of hearing loss in the better hearing ear, cochlear implant status, intensity of oral education, parent-child interaction, and the number of languages spoken in the home. These factors were used in a linear multiple regression analysis to assess their contribution to auditory-based communication outcomes. Five outcome measures, evaluated at regular intervals in children starting at age 3, included measures of speech perception (Pediatric Speech Intelligibility and Online Imitative Test of Speech Pattern Contrast Perception), speech production (Arizona-3), and spoken language (Reynell Expressive and Receptive Language). The age at fitting of amplification ranged from 1 to 72 mo, and the degree of hearing loss ranged from mild to profound. Age at fitting of amplification showed the largest influence and was a significant factor in all outcome models. The degree of hearing loss was an important factor in the modeling of speech production and spoken language outcomes. Cochlear implant use was the other factor that contributed significantly to speech perception, speech production, and language outcomes. Other factors contributed sparsely to the models. Prospective longitudinal studies of children are important to establish relationships between subject factors and outcomes. This study clearly

  7. Sleep Deprivation and the Epigenome

    Directory of Open Access Journals (Sweden)

    Marie E. Gaine

    2018-02-01

    Full Text Available Sleep deprivation disrupts the lives of millions of people every day and has a profound impact on the molecular biology of the brain. These effects begin as changes within a neuron, at the DNA and RNA level, and result in alterations in neuronal plasticity and dysregulation of many cognitive functions including learning and memory. The epigenome plays a critical role in regulating gene expression in the context of memory storage. In this review article, we begin by describing the effects of epigenetic alterations on the regulation of gene expression, focusing on the most common epigenetic mechanisms: (i DNA methylation; (ii histone modifications; and (iii non-coding RNAs. We then discuss evidence suggesting that sleep loss impacts the epigenome and that these epigenetic alterations might mediate the changes in cognition seen following disruption of sleep. The link between sleep and the epigenome is only beginning to be elucidated, but clear evidence exists that epigenetic alterations occur following sleep deprivation. In the future, these changes to the epigenome could be utilized as biomarkers of sleep loss or as therapeutic targets for sleep-related disorders.

  8. Sleep Deprivation and the Epigenome.

    Science.gov (United States)

    Gaine, Marie E; Chatterjee, Snehajyoti; Abel, Ted

    2018-01-01

    Sleep deprivation disrupts the lives of millions of people every day and has a profound impact on the molecular biology of the brain. These effects begin as changes within a neuron, at the DNA and RNA level, and result in alterations in neuronal plasticity and dysregulation of many cognitive functions including learning and memory. The epigenome plays a critical role in regulating gene expression in the context of memory storage. In this review article, we begin by describing the effects of epigenetic alterations on the regulation of gene expression, focusing on the most common epigenetic mechanisms: (i) DNA methylation; (ii) histone modifications; and (iii) non-coding RNAs. We then discuss evidence suggesting that sleep loss impacts the epigenome and that these epigenetic alterations might mediate the changes in cognition seen following disruption of sleep. The link between sleep and the epigenome is only beginning to be elucidated, but clear evidence exists that epigenetic alterations occur following sleep deprivation. In the future, these changes to the epigenome could be utilized as biomarkers of sleep loss or as therapeutic targets for sleep-related disorders.

  9. Sleep timing is more important than sleep length or quality for medical school performance

    NARCIS (Netherlands)

    Genzel, L.K.E.; Ahrberg, K.; Roselli, C.; Niedermaier, S.; Steiger, A.; Dresler, M.; Roenneberg, T.

    2013-01-01

    Overwhelming evidence supports the importance of sleep for memory consolidation. Medical students are often deprived of sufficient sleep due to large amounts of clinical duties and university load, we therefore investigated how study and sleep habits influence university performance. We performed a

  10. Factors influencing maternal decision-making for the infant sleep environment in families at higher risk of SIDS:a qualitative study

    OpenAIRE

    Pease, Anna; Ingram, Jenny; Blair, Pete; Fleming, Peter

    2017-01-01

    Objective: Qualitative interviews with mothers of babies at higher risk of sudden infant death syndrome (SIDS) were carried out to understand their views and decision-making process on the infant sleep environment and safe sleep messages.Design and setting: Twenty semi-structured interviews were conducted between February and November 2014 in deprived areas of Bristol, UK. Mothers were asked about their decision-making for the infant sleep environment and safe sleep messages including infant ...

  11. Sleep and Epilepsy: Strange Bedfellows No More.

    Science.gov (United States)

    St Louis, Erik K

    2011-09-01

    Ancient philosophers and theologians believed that altered consciousness freed the mind to prophesy the future, equating sleep with seizures. Only recently has the bidirectional influences of epilepsy and sleep upon one another received more substantive analysis. This article reviews the complex and increasingly recognized interrelationships between sleep and epilepsy. NREM sleep differentially activates interictal epileptiform discharges during slow wave (N3) sleep, while ictal seizure events occur more frequently during light NREM stages N1 and N2. The most commonly encountered types of sleep-related epilepsies (those with preferential occurrence during sleep or following arousal) include frontal and temporal lobe partial epilepsies in adults, and benign epilepsy of childhood with centrotemporal spikes (benign rolandic epilepsy) and juvenile myoclonic epilepsy in children and adolescents. Comorbid sleep disorders are frequent in patients with epilepsy, particularly obstructive sleep apnea in refractory epilepsy patients which may aggravate seizure burden, while treatment with nasal continuous positive airway pressure often improves seizure frequency. Distinguishing nocturnal events such as NREM parasomnias (confusional arousals, sleep walking, and night terrors), REM parasomnias including REM sleep behavior disorder, and nocturnal seizures if frequently difficult and benefits from careful history taking and video-EEG-polysomnography in selected cases. Differentiating nocturnal seizures from primary sleep disorders is essential for determining appropriate therapy, and recognizing co-existent sleep disorders in patients with epilepsy may improve their seizure burden and quality of life.

  12. High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women.

    Science.gov (United States)

    Jakubowicz, Daniela; Barnea, Maayan; Wainstein, Julio; Froy, Oren

    2013-12-01

    Few studies examined the association between time-of-day of nutrient intake and the metabolic syndrome. Our goal was to compare a weight loss diet with high caloric intake during breakfast to an isocaloric diet with high caloric intake at dinner. Overweight and obese women (BMI 32.4 ± 1.8 kg/m(2) ) with metabolic syndrome were randomized into two isocaloric (~1400 kcal) weight loss groups, a breakfast (BF) (700 kcal breakfast, 500 kcal lunch, 200 kcal dinner) or a dinner (D) group (200 kcal breakfast, 500 kcal lunch, 700 kcal dinner) for 12 weeks. The BF group showed greater weight loss and waist circumference reduction. Although fasting glucose, insulin, and ghrelin were reduced in both groups, fasting glucose, insulin, and HOMA-IR decreased significantly to a greater extent in the BF group. Mean triglyceride levels decreased by 33.6% in the BF group, but increased by 14.6% in the D group. Oral glucose tolerance test led to a greater decrease of glucose and insulin in the BF group. In response to meal challenges, the overall daily glucose, insulin, ghrelin, and mean hunger scores were significantly lower, whereas mean satiety scores were significantly higher in the BF group. High-calorie breakfast with reduced intake at dinner is beneficial and might be a useful alternative for the management of obesity and metabolic syndrome. Copyright © 2013 The Obesity Society.

  13. Ac-loss measurement of coated conductors: The influence of the pick-up coil position

    International Nuclear Information System (INIS)

    Schmidt, Curt

    2008-01-01

    The ac-loss measurement by the magnetization method requires calibration for obtaining absolute values. A convenient way of calibration is the calorimetric measurement which yields, within the measuring accuracy, absolute loss values. In the magnetization measurement the hysteresis loop of sample magnetization which determines the losses is measured via the integration of magnetic flux penetrating a pick-up coil. The ratio of flux integral to magnetization integral and hence the calibration factor is however, for a given pick-up coil geometry, not exactly a constant, but depends on the magnetization current pattern within the sample. Especially for thin tapes in perpendicular external field this effect has to be taken into consideration in order to avoid miss measurements. The relation between measured flux and sample magnetization was calculated for special cases of magnetization current distribution in the sample as a function of the pick-up coil position. Furthermore calibration factors were measured as a function of the ac-field amplitude and the result compared with available theoretical models. A good agreement was found between experiment and theory

  14. Studying influence of two effective parameters on network losses in transmission expansion planning using DCGA

    International Nuclear Information System (INIS)

    Shayeghi, H.; Jalilzadeh, S.; Mahdavi, M.; Hadadian, H.

    2008-01-01

    Transmission network expansion planning (TNEP) is a basic part of power network planning that determines where, when and how many new transmission lines should be added to the network. Its task is to minimize the network construction and operational cost, while meeting imposed technical, economic and reliability constraints. Up till now, various methods have been proposed for solution of the static transmission network expansion planning (STNEP) problem. But, in all of them, the effect of two important parameters i.e., inflation rate and load growth factor on network losses has not been investigated. Thus, in this paper, STNEP is being studied considering the effect of inflation rate and load growth factor on the network losses in a transmission network with different voltage levels using a decimal codification genetic algorithm (DCGA). The effectiveness of the proposed idea is tested on the Garver's six-bus network. The results evaluation reveals that the inflation rate and load growth factor have important effect on the network losses and subsequent network arrangement. In addition, considering the effect of two above-mentioned parameters (inflation rate and load growth factor) in expansion planning of transmission networks with various line voltage levels is caused that the total expansion cost of the network (expansion costs and the operational cost) is calculated more exactly and therefore the network satisfies the requirements of delivering electric power more safely and reliably to load centers

  15. Factors influencing pursuit of hearing evaluation: Enhancing the health belief model with perceived burden from hearing loss on communication partners.

    Science.gov (United States)

    Schulz, Kristine A; Modeste, Naomi; Lee, Jerry; Roberts, Rhonda; Saunders, Gabrielle H; Witsell, David L

    2016-07-01

    There is limited application of health behavior-based theoretical models in hearing healthcare, yet other fields utilizing these models have shown their value in affecting behavior change. The health belief model (HBM) has demonstrated appropriateness for hearing research. This study assessed factors that influence an individual with suspected hearing loss to pursue clinical evaluation, with a focus on perceived burden of hearing loss on communication partners, using the HBM as a framework. Cross-sectional design collecting demographics along with three validated hearing-loss related questionnaires. Patients from Duke University Medical Center Otolaryngology Clinic aged 55-75 years who indicated a communication partner had expressed concern about their hearing. A final sample of 413 completed questionnaire sets was achieved. The HBM model construct 'cues to action' was a significant (p loss on communication partners was a significant (p model fit when added to the HBM: 72.0% correct prediction when burden is added versus 66.6% when not (p models in hearing healthcare is warranted.

  16. Sleep Disturbance and Short Sleep as Risk Factors for Depression and Perceived Medical Errors in First-Year Residents.

    Science.gov (United States)

    Kalmbach, David A; Arnedt, J Todd; Song, Peter X; Guille, Constance; Sen, Srijan

    2017-03-01

    While short and poor quality sleep among training physicians has long been recognized as problematic, the longitudinal relationships among sleep, work hours, mood, and work performance are not well understood. Here, we prospectively characterize the risk of depression and medical errors based on preinternship sleep disturbance, internship-related sleep duration, and duty hours. Survey data from 1215 nondepressed interns were collected at preinternship baseline, then 3 and 6 months into internship. We examined how preinternship sleep quality and internship sleep and work hours affected risk of depression at 3 months, per the Patient Health Questionnaire 9. We then examined the impact of sleep loss and work hours on depression persistence from 3 to 6 months. Finally, we compared self-reported errors among interns based on nightly sleep duration (≤6 hr vs. >6 hr), weekly work hours (Poorly sleeping trainees obtained less sleep and were at elevated risk of depression in the first months of internship. Short sleep (≤6 hr nightly) during internship mediated the relationship between sleep disturbance and depression risk, and sleep loss led to a chronic course for depression. Depression rates were highest among interns with both sleep disturbance and short sleep. Elevated medical error rates were reported by physicians sleeping ≤6 hr per night, working ≥ 70 weekly hours, and who were acutely or chronically depressed. Sleep disturbance and internship-enforced short sleep increase risk of depression development and chronicity and medical errors. Interventions targeting sleep problems prior to and during residency hold promise for curbing depression rates and improving patient care. © 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.

  17. Hypocretin (orexin) loss in Alzheimer's disease.

    NARCIS (Netherlands)

    Fronczek, R.; Geest, S. de; Frolich, M.; Overeem, S.; Roelandse, F.W.; Lammers, G.J.; Swaab, D.F.

    2012-01-01

    Sleep disturbances in Alzheimer's disease (AD) patients are associated with the severity of dementia and are often the primary reason for institutionalization. These sleep problems partly resemble core symptoms of narcolepsy, a sleep disorder caused by a general loss of the neurotransmitter

  18. Hypocretin (orexin) loss in Alzheimer's disease

    NARCIS (Netherlands)

    Fronczek, Rolf; van Geest, Sarita; Frölich, Marijke; Overeem, Sebastiaan; Roelandse, Freek W. C.; Lammers, Gert Jan; Swaab, Dick F.

    2012-01-01

    Sleep disturbances in Alzheimer's disease (AD) patients are associated with the severity of dementia and are often the primary reason for institutionalization. These sleep problems partly resemble core symptoms of narcolepsy, a sleep disorder caused by a general loss of the neurotransmitter

  19. Sleeping to fuel the immune system: mammalian sleep and resistance to parasites

    Directory of Open Access Journals (Sweden)

    Opp Mark R

    2009-01-01

    Full Text Available Abstract Sleep is an enigma. Why animals forgo eating and reproducing, while potentially increasing their risk of predation remains unknown. Although some may question whether all animals sleep, it is clear that all living organisms possess defenses against attack by pathogens. Immune responses of humans and animals are impaired by sleep loss, and responses to immune challenge include altered sleep. Thus, sleep is hypothesized to be a component of the acute phase response to infection and to function in host defense. Examining phylogenetic relationships among sleep parameters, components of the mammalian immune system and resistance to infection may provide insight into the evolution of sleep and lead to a greater appreciation for the role of sleep in host defense.

  20. Hydrologic Conditions that Influence Streamflow Losses in a Karst Region of the Upper Peace River, Polk County, Florida

    Science.gov (United States)

    Metz, P.A.; Lewelling, B.R.

    2009-01-01

    The upper Peace River from Bartow to Fort Meade, Florida, is described as a groundwater recharge area, reflecting a reversal from historical groundwater discharge patterns that existed prior to the 1950s. The upper Peace River channel and floodplain are characterized by extensive karst development, with numerous fractures, crevasses, and sinks that have been eroded in the near-surface and underlying carbonate bedrock. With the reversal in groundwater head gradients, river water is lost to the underlying groundwater system through these karst features. An investigation was conducted to evaluate the hydrologic conditions that influence streamflow losses in the karst region of the upper Peace River. The upper Peace River is located in a basin that has been altered substantially by phosphate mining and increases in groundwater use. These alterations have changed groundwater flow patterns and caused streamflow declines through time. Hydrologic factors that have had the greatest influence on streamflow declines in the upper Peace River include the lowering of the potentiometric surfaces of the intermediate aquifer system and Upper Floridan aquifer beneath the riverbed elevation due to below-average rainfall (droughts), increases in groundwater use, and the presence of numerous karst features in the low-water channel and floodplain that enhance the loss of streamflow. Seepage runs conducted along the upper Peace River, from Bartow to Fort Meade, indicate that the greatest streamflow losses occurred along an approximate 2-mile section of the river beginning about 1 mile south of the Peace River at Bartow gaging station. Along the low-water and floodplain channel of this 2-mile section, there are about 10 prominent karst features that influence streamflow losses. Losses from the individual karst features ranged from 0.22 to 16 cubic feet per second based on measurements made between 2002 and 2007. The largest measured flow loss for all the karst features was about 50 cubic

  1. Sleep and Media Screens in Pediatric Ages

    Directory of Open Access Journals (Sweden)

    Filipe Cerca

    2018-04-01

    Full Text Available Introduction: Sleep plays an essential role in children’s physical, emotional and behavioral health. Understanding the sleep architecture, sleep duration requirements as well as the interference of media screens activity with sleep across pediatric ages is essential in order to provide an adequate anticipatory guidance for the children’s parents. Objectives: To review current knowledge on sleep physiology with a particular focus in sleep duration requirements across pediatric ages and on the influence of media screen activity on children and adolescent sleep. Methods: Revision of meta-analysis research studies, systematic reviews, standards of clinical orientation and original research published in Portuguese or English between 01/2000 and 08/2017 on Pubmed / Medline using the following MeSH terms: sleep; sleep requirements; sleep physiology; media screen; child and neurodevelopment. Development: Sleep architecture and sleep duration requirements undergo constant change with age. Despite interindividual differences, optimal sleep duration intervals as well as nap times, which constitute an essential component of children’s sleep, should be followed. Along children’s age progression, other parameters need to be considered in order to maintain optimal sleep quality. The restriction of media screen use at bedtime assumes special relevance, as there is growing evidence pointing towards an association between shortened sleep time and the misuse of screen devices. Adolescents represent a particularly vulnerable population to media screens effects. Importantly, screen overuse and media content may be responsible for higher propensity for obesity, risky behavior, depression, impaired academic performance, decreased social skills and attention difficulties. Conclusion: Anticipatory guidance for parents addressing sleep optimization and media exposure should be routinely provided as a part of health follow-up. Physicians should be capacitated to

  2. Sleep extension normalizes ERP of waking auditory sensory gating in healthy habitually short sleeping individuals.

    Science.gov (United States)

    Gumenyuk, Valentina; Korzyukov, Oleg; Roth, Thomas; Bowyer, Susan M; Drake, Christopher L

    2013-01-01

    Chronic sleep loss has been associated with increased daytime sleepiness, as well as impairments in memory and attentional processes. In the present study, we evaluated the neuronal changes of a pre-attentive process of wake auditory sensory gating, measured by brain event-related potential (ERP)--P50 in eight normal sleepers (NS) (habitual total sleep time (TST) 7 h 32 m) vs. eight chronic short sleeping individuals (SS) (habitual TST ≤6 h). To evaluate the effect of sleep extension on sensory gating, the extended sleep condition was performed in chronic short sleeping individuals. Thus, one week of time in bed (6 h 11 m) corresponding to habitual short sleep (hSS), and one week of extended time (∼ 8 h 25 m) in bed corresponding to extended sleep (eSS), were counterbalanced in the SS group. The gating ERP assessment was performed on the last day after each sleep condition week (normal sleep and habitual short and extended sleep), and was separated by one week with habitual total sleep time and monitored by a sleep diary. We found that amplitude of gating was lower in SS group compared to that in NS group (0.3 µV vs. 1.2 µV, at Cz electrode respectively). The results of the group × laterality interaction showed that the reduction of gating amplitude in the SS group was due to lower amplitude over the left hemisphere and central-midline sites relative to that in the NS group. After sleep extension the amplitude of gating increased in chronic short sleeping individuals relative to their habitual short sleep condition. The sleep condition × frontality interaction analysis confirmed that sleep extension significantly increased the amplitude of gating over frontal and central brain areas compared to parietal brain areas.

  3. Sleep extension normalizes ERP of waking auditory sensory gating in healthy habitually short sleeping individuals.

    Directory of Open Access Journals (Sweden)

    Valentina Gumenyuk

    Full Text Available Chronic sleep loss has been associated with increased daytime sleepiness, as well as impairments in memory and attentional processes. In the present study, we evaluated the neuronal changes of a pre-attentive process of wake auditory sensory gating, measured by brain event-related potential (ERP--P50 in eight normal sleepers (NS (habitual total sleep time (TST 7 h 32 m vs. eight chronic short sleeping individuals (SS (habitual TST ≤6 h. To evaluate the effect of sleep extension on sensory gating, the extended sleep condition was performed in chronic short sleeping individuals. Thus, one week of time in bed (6 h 11 m corresponding to habitual short sleep (hSS, and one week of extended time (∼ 8 h 25 m in bed corresponding to extended sleep (eSS, were counterbalanced in the SS group. The gating ERP assessment was performed on the last day after each sleep condition week (normal sleep and habitual short and extended sleep, and was separated by one week with habitual total sleep time and monitored by a sleep diary. We found that amplitude of gating was lower in SS group compared to that in NS group (0.3 µV vs. 1.2 µV, at Cz electrode respectively. The results of the group × laterality interaction showed that the reduction of gating amplitude in the SS group was due to lower amplitude over the left hemisphere and central-midline sites relative to that in the NS group. After sleep extension the amplitude of gating increased in chronic short sleeping individuals relative to their habitual short sleep condition. The sleep condition × frontality interaction analysis confirmed that sleep extension significantly increased the amplitude of gating over frontal and central brain areas compared to parietal brain areas.

  4. The influence of implant-abutment connection to peri-implant bone loss: A systematic review and meta-analysis.

    Science.gov (United States)

    Caricasulo, Riccardo; Malchiodi, Luciano; Ghensi, Paolo; Fantozzi, Giuliano; Cucchi, Alessandro

    2018-05-15

    Different implant-abutment connections are available and it has been claimed they could have an effect on marginal bone loss. The aim of this review is to establish if implant connection configuration influences peri-implant bone loss (PBL) after functional loading. A specific question was formulated according to the Population, Intervention, Control, and Outcome (PICO): Does the type of implant-abutment connection (external, internal, or conical) have an influence on peri-implant bone loss? A PubMed/MEDLINE electronic search was conducted to identify English language publications published in international journals during the last decade (from 2006 to 2016). The search was conducted by using the Medical Subject Headings (MeSH) keywords "dental implants OR dental abutment AND external connection OR internal connection OR conical connection OR Morse Taper." Selected studies were randomized clinical trials and prospective studies; in vitro studies, case reports and retrospective studies were excluded. Titles and abstracts and, in the second phase, full texts, were evaluated autonomously and in duplicate by two reviewers. A total of 1649 articles were found, but only 14 studies met the pre-established inclusion criteria and were considered suitable for meta-analytic analysis. The network meta-analysis (NMA) suggested a significant difference between the external and the conical connections; this was less evident for the internal and conical ones. Platform-switching (PS) seemed to positively affect bone levels, non-regarding the implant-connection it was applied to. Within the limitations of this systematic review, it can be concluded that crestal bone levels are better maintained in the short-medium term when internal kinds of interface are adopted. In particular, conical connections seem to be more advantageous, showing lower peri-implant bone loss, but further studies are necessary to investigate the efficacy of implant-abutment connection on stability of crestal

  5. Future Directions in Sleep and Developmental Psychopathology.

    Science.gov (United States)

    Meltzer, Lisa J

    2017-01-01

    It is critical for psychologists to gain a better understanding about the intersection between sleep and developmental psychopathology. However, while many strive to answer the question of whether sleep causes developmental psychopathology, or vice versa, ultimately the relationship between sleep and developmental psychopathology is complex and dynamic. This article considers future directions in the field of clinical child and adolescent psychology that go beyond this mechanistic question, highlighting areas important to address for clinicians and researchers who strive to better understand how best to serve children and adolescents with developmental psychopathology. Questions are presented about what is normal in terms of sleep across development, the role of individual variability in terms of sleep needs and vulnerability to sleep loss, and how sleep may serve as a risk or resilience factor for developmental psychopathology, concluding with considerations for interventions.

  6. Influence of Ovarian Hormones on Strength Loss in Healthy and Dystrophic Female Mice

    Science.gov (United States)

    Kosir, Allison M.; Mader, Tara L.; Greising, Angela G.; Novotny, Susan A.; Baltgalvis, Kristen A.; Lowe, Dawn A.

    2014-01-01

    Purpose The primary objective of this study was to determine if strength loss and recovery following eccentric contractions is impaired in healthy and dystrophic female mice with low levels of ovarian hormones. Methods Female C57BL/6 (wildtype) or mdx mice were randomly assigned to ovarian-intact (Sham) and ovariectomized (Ovx) groups. Anterior crural muscles were tested for susceptibility to injury from 150 or 50 eccentric contractions in wildtype and mdx mice, respectively. An additional experiment challenged mdx mice with a 2-wk treadmill running protocol followed by an eccentric contraction injury to posterior crural muscles. Functional recovery from injury was evaluated in wildtype mice by measuring isometric torque 3, 7, 14, or 21 days following injury. Results Ovarian hormone deficiency in wildtype mice did not impact susceptibility to injury as the ~50% isometric torque loss following eccentric contractions did not differ between Sham and Ovx mice (p=0.121). Similarly in mdx mice, hormone deficiency did not affect percent of pre injury isometric torque lost by anterior crural muscles following eccentric contractions (p=0.952), but the percent of pre injury torque in posterior crural muscles was lower in Ovx compared to Sham mice (p=0.014). Recovery from injury in wildtype mice was affected by hormone deficiency. Sham mice recovered pre injury isometric strength by 14 days (96 ± 2%) while Ovx mice maintained deficits at 14 and 21 days post injury (80 ± 3% and 84 ± 2%; phormone status did not impact the vulnerability of skeletal muscle to strength loss following eccentric contractions. However, ovarian hormone deficiency did impair the recovery of muscle strength in female mice. PMID:25255128

  7. Influence of steam generator tube ruptures during semiscale loss-of-coolant experiments

    International Nuclear Information System (INIS)

    Cozzuol, J.M.; Larson, T.K.

    1978-01-01

    Tests which simulated rupture of steam generator tubes during loss-of-coolant experiments in a PWR type system have been conducted in the Semiscale Mod-1 system. Analysis of test data indicates that high rod cladding temperatures occured only for a band of tube ruptures (between 12 and 20 tubes) and that the peak cladding temperatures attained within this band were strongly dependent on the magnitude of the tube rupture flow rates. Maximum cladding temperature of about 1255 K was observed for tests which simulated tube ruptures within this narrow band. (author)

  8. Sociocultural and Individual Influences on Muscle Gain and Weight Loss Strategies among Adolescent Boys and Girls

    Science.gov (United States)

    Ricciardelli, Lina A.; McCabe, Marita P.

    2003-01-01

    The study examined the role of body dissatisfaction, body image importance, sociocultural influences (media and parent and peer encouragement), self-esteem and negative affect on body change strategies to decrease weight and increase muscles in adolescent boys and girls. Surveys were administered to 587 boys and 598 girls aged between 11 and 15…

  9. Technology-Assisted Behavioral Intervention to Extend Sleep Duration: Development and Design of the Sleep Bunny Mobile App.

    Science.gov (United States)

    Baron, Kelly Glazer; Duffecy, Jennifer; Reid, Kathryn; Begale, Mark; Caccamo, Lauren

    2018-01-10

    Despite the high prevalence of short sleep duration (29.2% of adults sleep popularity of wearable sleep trackers provides an opportunity to engage users in interventions. The objective of this study was to outline the theoretical foundation and iterative process of designing the "Sleep Bunny," a technology-assisted sleep extension intervention including a mobile phone app, wearable sleep tracker, and brief telephone coaching. We conducted a two-step process in the development of this intervention, which was as follows: (1) user testing of the app and (2) a field trial that was completed by 2 participants with short sleep duration and a cardiovascular disease risk factor linked to short sleep duration (body mass index [BMI] >25). All participants had habitual sleep duration consequences of sleep loss. ©Kelly Glazer Baron, Jennifer Duffecy, Kathryn Reid, Mark Begale, Lauren Caccamo. Originally published in JMIR Mental Health (http://mental.jmir.org), 10.01.2018.

  10. The influence of some selected variables from accounting system on profit or loss of agricultural companies in the Slovak republic

    Directory of Open Access Journals (Sweden)

    Alexandra Ferenczi Vaňová

    2017-01-01

    Full Text Available 1024x768 The article presents the influence assessment of significance of some selected variables from the entrepreneurs' accounting system on the achieved profit or loss of the agricultural companies in the Slovak Republic. Accounting information serves as an active tool for internal users for operational as well as strategic company management, and for external users the information is determined as legally binding output information which is a subject to disclosure. Individual financial statements of assessed agricultural companies are considered to be the relevant source of information. Agricultural companies are represented by commercial companies and agricultural cooperatives. Profit or loss after income tax presents the final complex effect of economic company's performance. The existence and development of companies is conditioned by assets which amount and structure depend on focus and the range of subject activity but as well as on specific factors set by the production process in the agricultural primary production. The increase in liabilities is notable by the influence of unsufficient amount of own company funding sources, mainly the increase in trade payables. The continuance of company reproduction process is secured by a bank loan drawdown. The income situation of companies of agricultural primary production is favourably influenced by the subsidies of non-investment character. During the observed period of years 2004 - 2014 the examined variables were assessed by means of statistical methods. The obtained results of rate determination of statistical correlation between selected variables by means of classical canonical analysis and non-parametric correlation analysis secured that in the assessed group of companies all analysed variables influenced statistically significantly profit or loss after income tax, mainly the total value of assets and non-investment subsidies, except for years 2010, 2012 a 2013, when the statistically

  11. Sleep: a reality or dream for the hospitalized adult?

    Science.gov (United States)

    Pulling, C; Seaman, S

    1993-01-01

    Nursing research literature is examined to determine the extent of sleep loss for the hospitalized adult. Research from the patient's perspective, nurses' assessment of patient's sleep and somnographic studies are considered. Although these three methods are inconsistent in the exact extent of sleep loss, all suggest that hospitalized patients experience less sleep than their normal pattern. Reasons for patients losing sleep are explored. Environmental factors in critical care areas are the most cited reason for loss of sleep yet other reasons are suggested. Consequences of sleep loss are explored. Some nursing interventions offered in the existing literature are examined for their feasibility. Finally, directions for future research are offered from this review of the literature.

  12. Immigrants Coping with Transnational Deaths and Bereavement: The Influence of Migratory Loss and Anticipatory Grief.

    Science.gov (United States)

    Nesteruk, Olena

    2017-12-14

    This study examines immigrants' experiences of bereavement and coping with the deaths of family members in a transnational context. Data were collected through in-depth personal interviews with middle-aged and older immigrants from different countries of origin, who have been living in the United States for a majority of their adult lives. Thematic analysis of participants' narratives showed that immigrants' geographic distance from family complicated caregiving circumstances and rituals surrounding burial, and impacted the grieving process. At the same time, this distance also served as an emotional barrier and provided protection from prolonged grief. Immigrants' U.S.-based family and work responsibilities served as buffers from prolonged grief. Over time, immigrants became Americanized in their attitudes toward coping with death and favored a fast return to productive activities. Finally, immigrants' experience of migratory loss and anticipatory grief early in immigration, along with their personal growth and resilience developed over time, impacted their bereavement experiences later in life. Considering the limitations and the exploratory nature of the present study, further research is needed to investigate the specifics of coping with loss and bereavement among immigrants. © 2017 Family Process Institute.

  13. Environmental lead pollution and its possible influence on tooth loss and hard dental tissue lesions.

    Science.gov (United States)

    Cenić-Milosević, Desanka; Mileusnić, Ivan; Kolak, Veljko; Pejanović, Djordje; Ristić, Tamara; Jakovljević, Ankica; Popović, Milica; Pesić, Dragana; Melih, Irena

    2013-08-01

    Environmental lead (Pb) pollution is a global problem. Hard dental tissue is capable of accumulating lead and other hard metals from the environment. The aim of this study was to investigate any correlation between the concentration of lead in teeth extracted from inhabitants of Pancevo and Belgrade, Serbia, belonging to different age groups and occurrence of tooth loss, caries and non-carious lesions. A total of 160 volunteers were chosen consecutively from Pancevo (the experimental group) and Belgrade (the control group) and divided into 5 age subgroups of 32 subjects each. Clinical examination consisted of caries and hard dental tissue diagnostics. The Decayed Missing Filled Teeth (DMFT) Index and Significant Caries Index were calculated. Extracted teeth were freed of any organic residue by UV digestion and subjected to voltammetric analysis for the content of lead. The average DMFT scores in Pancevo (20.41) were higher than in Belgrade (16.52); in the patients aged 31-40 and 41-50 years the difference was significant (p lead concentration and the number of extracted teeth, number of carious lesions and non-carious lesions found in the patients living in Pancevo, one possible cause of tooth loss and hard dental tissue damage could be a long-term environmental exposure to lead.

  14. Retaining Residual Ovarian Tissue following Ovarian Failure Has Limited Influence on Bone Loss in Aged Mice

    Directory of Open Access Journals (Sweden)

    Zelieann R. Craig

    2010-01-01

    Full Text Available Previous work showed that retaining residual ovarian tissue protects young mice from accelerated bone loss following ovarian failure. The present study was designed to determine whether this protection is also present in aged animals. Aged (9–12 months C57BL/6Hsd female mice were divided into: CON (vehicle, VCD (160 mg/kg; 15d, or OVX (ovariectomized. Lumbar BMD was monitored by DXA and μCT used to assess vertebral microarchitecture. BMD was not different between VCD and CON at any time point but was lower (P<.05 than baseline, starting 1 month after ovarian failure in VCD and OVX mice. Following μCT analysis there were no differences between CON and VCD, but OVX mice had lower bone volume fraction, trabecular thickness, and a trend for decreased connectivity density. These findings provide evidence that retention of residual ovarian tissue may protect aged follicle-depleted mice from accelerated bone loss to a lesser extent than that observed in young mice.

  15. Medicines for sleep

    Science.gov (United States)

    Benzodiazepines; Sedatives; Hypnotics; Sleeping pills; Insomnia - medicines; Sleep disorder - medicines ... are commonly used to treat allergies. While these sleep aids are not addictive, your body becomes used ...

  16. Influence of dexamethasone and weight loss on the regulation of serum leptin levels in obese individuals

    Directory of Open Access Journals (Sweden)

    D.D.G. Lerario

    2001-04-01

    Full Text Available The adipocyte hormone leptin is thought to serve as a signal to the central nervous system reflecting the status of fat stores. Serum leptin levels and adipocyte leptin messenger RNA levels are clearly increased in obesity. Nevertheless, the factors regulating leptin production are not fully understood. The aim of this study was to determine the effects of in vivo administration of the synthetic glucocorticoid dexamethasone and weight loss on serum leptin levels in two independent protocols. Twenty-five obese subjects were studied (18 women and 7 men, mean age 26.6 ± 6 years, BMI 31.1 ± 2.5 kg/m², %fat 40.3 ± 8.3 and compared at baseline to 22 healthy individuals. Serum levels of leptin, insulin, proinsulin and glucose were assessed at baseline and after ingestion of dexamethasone, 4 mg per day (2 mg, twice daily for two consecutive days. To study the effects of weight loss on serum leptin, 17 of the obese subjects were submitted to a low-calorie dietary intervention trial for 8 weeks and again blood samples were collected. Serum leptin levels were significantly higher in the obese group compared to the control group and a high positive correlation between leptinemia and the magnitude of fat mass was found (r = 0.88, P<0.0001. After dexamethasone, there was a significant increase in serum leptin levels (22.9 ± 12.3 vs 51.4 ± 23.3 ng/ml, P<0.05. Weight loss (86.1 ± 15.1 vs 80.6 ± 14.2 kg, P<0.05 led to a reduction in leptin levels (25.13 ± 12.8 vs 15.9 ± 9.1 ng/ml, P<0.05. We conclude that serum leptin levels are primordially dependent on fat mass magnitude. Glucocorticoids at supraphysiologic levels are potent secretagogues of leptin in obese subjects and a mild fat mass reduction leads to a disproportionate decrease in serum leptin levels. This suggests that, in addition to the changes in fat mass, complex nutritional and hormonal interactions may also play an important role in the regulation of leptin levels.

  17. Influence of radiation defects on electrical losses in silicon diodes irradiated with electrons

    International Nuclear Information System (INIS)

    Poklonski, N. A.; Gorbachuk, N. I.; Shpakovski, S. V.; Lastovskii, S. B.; Wieck, A.

    2010-01-01

    Silicon diodes with a p + -n junction irradiated with 3.5-MeV electrons (the fluence ranged from 10 15 to 4 x 10 16 cm -2 ) have been studied. It is established that the dependence of the tangent of the angle of electrical losses tanδ on the frequency f of alternating current in the range f = 10 2 -10 6 Hz is a nonmonotonic function with two extrema: a minimum and a maximum. Transformation of the dependences tanδ(f) as the electron fluence and annealing temperature are increased is caused by a variation in the resistance of n-Si (the base region of the diodes) as a result of accumulation (as the fluence is increased) or disappearance and reconfiguration (in the course of annealing) of radiation defects. The role of time lag of the defect recharging in the formation of tanδ(f) is insignificant.

  18. Influence of craniofacial and upper spine morphology on mandibular advancement device treatment outcome in patients with obstructive sleep apnoea

    DEFF Research Database (Denmark)

    Svanholt, Palle; Petri, Niels; Wildschiødtz, Gordon

    2015-01-01

    Summary BACKGROUND/OBJECTIVES: The aim of the study was to assess cephalometric predictive markers in terms of craniofacial morphology including posterior cranial fossa and upper spine morphology for mandibular advancement device (MAD) treatment outcome in patients with obstructive sleep apnoea...... patients and the no success treatment group of 19 patients. Before MAD treatment lateral cephalograms were taken and analyses of the craniofacial morphology including the posterior cranial fossa and upper spine morphology were performed. Differences between the groups were analysed by Fisher's exact test......, t-test, and multiple regression analysis. RESULTS: Upper spine morphological deviations occurred non-significantly in 25 per cent in the success treatment group and in 42.1 per cent in the no success treatment group. Body mass index (BMI; P

  19. Analysis of dispersed frequency response for ionic glasses: influence of electrode and nearly constant loss effects

    International Nuclear Information System (INIS)

    Macdonald, J Ross

    2005-01-01

    Analysis by D L Sidebottom of the dispersive frequency response of the real-part of the conductivity, σ'(ω), for many alkali phosphate and metaphosphate glasses, using a fitting model involving a 'universal dynamic response' power law with an exponent n and a constant-loss term, led to anomalous n behaviour that he explained as arising from variable constriction of the local cation conduction space. In order to obtain adequate fits, he eliminated from the data all low-frequency decreases of σ'(ω) below the dc plateau, ones actually associated with electrode effects. Such a cut-off does not, however, eliminate electrode effects possibly present in the high-frequency part of the data range. The results of the present detailed analysis and fitting of both synthetic data and several of his experimental data sets show unequivocally that his anomalous n behaviour arose from neglecting electrode effects. Their inclusion, with or without data cut-off in the fitting model, leads to the expected high-frequency slope value of n = 2/3 associated with bulk conduction, as required by recently published topological effective-dimension considerations for dielectric relaxation in conductive systems. Further, the effects of the inclusion in a full fitting model of series and possibly parallel complex constant-phase-element contributions, representing electrode and nearly constant loss effects, respectively, have been investigated in detail. Such composite models usually lead to best fitting of either the full or cut-off complex data when they include the semi-universal, topologically based K1 bulk model, one indirectly derived from the assumption of stretched-exponential temporal behaviour

  20. Sleep and metabolic control: waking to a problem?

    Science.gov (United States)

    Trenell, Michael I; Marshall, Nathaniel S; Rogers, Naomi L

    2007-01-01

    1. The aim of the present review is to outline: (i) the association between sleep and metabolism; (ii) how sleep duration influences the development of disease; and (iii) how sex differences, ageing and obesity may potentially influence the relationship between sleep, metabolic control and subsequent disease. 2. Sleep is associated with a number of endocrine changes, including a change in insulin action in healthy young individuals. Sleep duration shows a prospective U-shaped relationship with all-cause mortality, cardiovascular disease and Type 2 diabetes. 3. Chronic sleep restriction is becoming more common. Experimental sleep restriction impedes daytime glucose control and increases appetite. 4. The sex hormones oestrogen and testosterone influence sleep duration and quality and may account for sex differences in the prevalence of sleep-related disorders. 5. Ageing is associated with a decreased sleep duration, decreased muscle mass and impaired insulin action. 6. Obesity impairs insulin action and is associated with the incidence and severity of obstructive sleep apnoea. 7. Sleep plays an integral role in metabolic control. Consequently, insufficient sleep may represent a modifiable risk factor for the development of Type 2 diabetes. The challenge ahead is to identify how sex differences, ageing and obesity could potentially influence the relationship between sleep and metabolism.

  1. Influences of microgap and micromotion of implant-abutment interface on marginal bone loss around implant neck.

    Science.gov (United States)

    Liu, Yang; Wang, Jiawei

    2017-11-01

    To review the influences and clinical implications of micro-gap and micro-motion of implant-abutment interface on marginal bone loss around the neck of implant. Literatures were searched based on the following Keywords: implant-abutment interface/implant-abutment connection/implant-abutment conjunction, microgap, micromotion/micromovement, microleakage, and current control methods available. The papers were then screened through titles, abstracts, and full texts. A total of 83 studies were included in the literature review. Two-piece implant systems are widely used in clinics. However, the production error and masticatory load result in the presence of microgap and micromotion between the implant and the abutment, which directly or indirectly causes microleakage and mechanical damage. Consequently, the degrees of microgap and micromotion further increase, and marginal bone absorption finally occurs. We summarize the influences of microgap and micromotion at the implant-abutment interface on marginal bone loss around the neck of the implant. We also recommend some feasible methods to reduce their effect. Clinicians and patients should pay more attention to the mechanisms as well as the control methods of microgap and micromotion. To reduce the corresponding detriment to the implant marginal bone, suitable Morse taper or hybrid connection implants and platform switching abutments should be selected, as well as other potential methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Influence of pore structure on carbon retention/loss in soil macro-aggregates

    Science.gov (United States)

    Quigley, Michelle; Kravchenko, Alexandra; Rivers, Mark

    2017-04-01

    carbon protect were disparate. In intact-structure aggregates, prior to incubation, there was no association between carbon distribution and pores. After incubation, significant correlations (α=0.05) were observed between abundance of 6-40 μm pores and both soil organic carbon (SOC) and δ13C. Sections containing more 6-40 μm pores also had increased amounts of SOC (r2=0.23) with higher presence of C4 carbon (r2=0.27). This indicates preferential preservation of older carbon in the pores of this size range. Prior to incubation, destroyed-structure aggregates had higher amounts of C3 carbon associated with 40-95 μm pores (r2=0.14), pointing to a greater presence of newly added carbon within these pores. However, after incubation there was a significant loss of SOC from these pores (r2=0.22) and, specifically, the loss of C3 carbon (r2=0.16). In the studied soil, pores of 6-40 μm size range appeared to control the preservation of older carbon, while 40-95 μm pores controlled the fate of newly added carbon. Older carbon preservation in 6-40 μm pores was mostly observed in macro-aggregates from the soil with intact structure, while the associations between 40-95 μm pores and gains and losses of newly added carbon were primarily observed in the macro-aggregates that were formed anew in the sieved soil during the plant growing experiment.

  3. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...

  4. Sleep Time: Media Hype vs. Diary Data

    Science.gov (United States)

    Michelson, William

    2011-01-01

    Sleep duration has figured into claims of two trends promoted recently as dysfunctional in the mass media. One is the observation that the population at large is sleeping less than before. The second is that the annual change from Standard Time to Daylight Savings (or summer) Time causes adverse effects, largely through the loss of an hour's…

  5. Sleep-Dependent Modulation of Metabolic Rate in Drosophila.

    Science.gov (United States)

    Stahl, Bethany A; Slocumb, Melissa E; Chaitin, Hersh; DiAngelo, Justin R; Keene, Alex C

    2017-08-01

    Dysregulation of sleep is associated with metabolic diseases, and metabolic rate (MR) is acutely regulated by sleep-wake behavior. In humans and rodent models, sleep loss is associated with obesity, reduced metabolic rate, and negative energy balance, yet little is known about the neural mechanisms governing interactions between sleep and metabolism. We have developed a system to simultaneously measure sleep and MR in individual Drosophila, allowing for interrogation of neural systems governing interactions between sleep and metabolic rate. Like mammals, MR in flies is reduced during sleep and increased during sleep deprivation suggesting sleep-dependent regulation of MR is conserved across phyla. The reduction of MR during sleep is not simply a consequence of inactivity because MR is reduced ~30 minutes following the onset of sleep, raising the possibility that CO2 production provides a metric to distinguish different sleep states in the fruit fly. To examine the relationship between sleep and metabolism, we determined basal and sleep-dependent changes in MR is reduced in starved flies, suggesting that starvation inhibits normal sleep-associated effects on metabolic rate. Further, translin mutant flies that fail to suppress sleep during starvation demonstrate a lower basal metabolic rate, but this rate was further reduced in response to starvation, revealing that regulation of starvation-induced changes in MR and sleep duration are genetically distinct. Therefore, this system provides the unique ability to simultaneously measure sleep and oxidative metabolism, providing novel insight into the physiological changes associated with sleep and wakefulness in the fruit fly. © 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.

  6. Preaching to the choir? The influence of personal relevance on the effects of gain- and loss-framed health-promoting messages

    NARCIS (Netherlands)

    Riet, van 't J.P.; Ruiter, de R.; Vries, de H.

    2012-01-01

    This article examines the moderating influence of personal relevance on the persuasive effects of gain- and loss-framed messages. We assessed current behaviour as a proxy for personal relevance, provided 169 participants with gain- and loss-framed messages advocating skin self-examination (SSE) and

  7. Environmental lead pollution and its possible influence on tooth loss and hard dental tissue lesions

    Directory of Open Access Journals (Sweden)

    Cenić-Milošević Desanka

    2013-01-01

    Full Text Available Bacground/Aim. Environmental lead (Pb pollution is a global problem. Hard dental tissue is capable of accumulating lead and other hard metals from the environment. The aim of this study was to investigate any correlation between the concentration of lead in teeth extracted from inhabitants of Pančevo and Belgrade, Serbia, belonging to different age groups and occurrence of tooth loss, caries and non-carious lesions. Methods. A total of 160 volunteers were chosen consecutively from Pančevo (the experimental group and Belgrade (the control group and divided into 5 age subgroups of 32 subjects each. Clinical examination consisted of caries and hard dental tissue diagnostics. The Decayed Missing Filled Teeth (DMFT Index and Significant Caries Index were calculated. Extracted teeth were freed of any organic residue by UV digestion and subjected to voltammetric analysis for the content of lead. Results. The average DMFT scores in Pančevo (20.41 were higher than in Belgrade (16.52; in the patients aged 31-40 and 41-50 years the difference was significant (p < 0.05 and highly significant in the patients aged 51-60 (23.69 vs 18.5, p < 0.01. Non-carious lesions were diagnosed in 71 (44% patients from Pančevo and 39 (24% patients from Belgrade. The concentrations of Pb in extracted teeth in all the groups from Pančevo were statistically significantly (p < 0.05 higher than in all the groups from Belgrade. In the patients from Pančevo correlations between Pb concentration in extracted teeth and the number of extracted teeth, the number of carious lesions and the number of non-carious lesions showed a statistical significance (p < 0.001, p < 0.01 and p < 0.001, respectively. Conclusion. According to correlations between lead concentration and the number of extracted teeth, number of carious lesions and non-carious lesions found in the patients living in Pančevo, one possible cause of tooth loss and hard dental tissue damage could be a long

  8. The influence of job stress, social support and health status on intermittent and chronic sleep disturbance: an 8-year longitudinal analysis.

    Science.gov (United States)

    Gosling, John A; Batterham, Philip J; Glozier, Nick; Christensen, Helen

    2014-08-01

    To determine the role of health status and social support in the relationship between job stress and sleep disturbance, for both intermittent and chronic sleep disturbance. A total of 1946 mid-life adults completed three questionnaires spanning an 8-year time frame. Sleep disturbance was assessed at each time point, and participants were classified as experiencing intermittent, chronic or no sleep disturbance across this 8-year period. Independent variables included a range of job stress measures, social support, physical and mental health, and demographic characteristics. After controlling for physical and mental health, perceived lack of job marketability increased risk of intermittent sleep disturbance (odds ratio (OR)=1.33, p=0.012). No other job stress measures were associated with either intermittent or chronic sleep disturbance after adjusting for years of education, social support, and employment status. Poorer mental and physical health status, although significantly increasing odds for intermittent sleep disturbance, represented a significantly greater increase in the odds for chronic sleep disturbance over and above intermittent disturbance (OR=0.96, pjob stress had an independent effect on chronic or intermittent sleep disturbance independent of health, social support, and education. Risk profiles for intermittent and chronic sleep disturbance did not differ with regard to job stress; however, various demographic and social support factors were distinguishing factors. Health status, both physical and mental, also showed a significantly greater impact on chronic sleep disturbance than intermittent sleep disturbance. Karasek's model of job strain had little value in predicting sleep disturbance outcomes. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Healthy Sleep

    Science.gov (United States)

    ... quality sleep, ask yourself Do you have trouble getting up in the morning? Do you have trouble focusing during the day? Do you doze off during the day? If you answered yes to these three questions, you should work on ...

  10. Influence of damping on proton energy loss in plasmas of all degeneracies

    International Nuclear Information System (INIS)

    Barriga-Carrasco, Manuel D.

    2007-01-01

    The purpose of the present paper is to describe the effects of electron-electron collisions on the stopping power of plasmas of any degeneracy. Plasma targets are considered fully ionized so electronic stopping is only due to the free electrons. We focus our analysis on plasmas which electronic density is around solid values n e ≅10 23 cm -3 and which temperature is around T≅10 eV; these plasmas are in the limit of weakly coupled plasmas. This type of plasma has not been studied extensively though it is very important for inertial confinement fusion. The electronic stopping is obtained from an exact quantum mechanical evaluation, which takes into account the degeneracy of the target plasma, and later it is compared with common classical and degenerate approximations. Differences are around 30% in some cases which can produce bigger mistakes in further energy deposition and projectile range studies. Then we consider electron-electron collisions in the exact quantum mechanical electronic stopping calculation. Now the maximum stopping occurs at velocities smaller than for the calculations without considering collisions for all kinds of plasmas analyzed. The energy loss enhances for velocities smaller than the velocity at maximum while decreases for higher velocities. Latter effects are magnified with increasing collision frequency. Differences with the same results for the case of not taking into account collisions are around 20% in the analyzed cases

  11. NITROGEN MANAGEMENT IN SUGARCANE AND ITS INFLUENCE ON YIELD, PROFITABILITY AND LEACHING LOSSES

    Directory of Open Access Journals (Sweden)

    Juan Carlos Moreno-Seceña

    2011-11-01

    Full Text Available The excessive use of nitrogen (N in sugarcane (Saccharum officinarum L. is a source of contamination for aquifers. The objective was to evaluate sugarcane yield, as well as profitability and amount of N leached resulting from the application of different split N doses. Three N doses (250, 200 and 150 kg ha-1 and three different application numbers (2, 3 and 4 were evaluated using a factorial design in randomized blocks. When the N dose was divided in three and four applications yields higher than 125 ton ha-1 were obtained. The greatest benefit-cost-ratio (1.8 resulted from using 150 kg ha-1 of N divided in three applications. The lowest N losses due to leaching were obtained using 150 kg ha-1 of N divided in three (16.8 kg ha-1 and four (15.4 kg ha-1 applications. Low N doses divided in three or four applications did not reduce sugarcane production; furthermore, it was more profitable and had a lower environmental impact by reducing N leaching.

  12. The Influence of Coronal Mass Ejections on the Mass-loss Rates of Hot-Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Cherenkov, A.; Bisikalo, D. [Institute of Astronomy of the Russian Academy of Sciences, 48 Pyatnitskaya St. 119017, Moscow (Russian Federation); Fossati, L.; Möstl, C., E-mail: bisikalo@inasan.ru [Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, A-8042 Graz (Austria)

    2017-09-01

    Hot-Jupiters are subject to extreme radiation and plasma flows coming from their host stars. Past ultraviolet Hubble Space Telescope observations, supported by hydrodynamic models, confirmed that these factors lead to the formation of an extended envelope, part of which lies beyond the Roche lobe. We use gas-dynamic simulations to study the impact of time variations in the parameters of the stellar wind, namely that of coronal mass ejections (CMEs), on the envelope of the typical hot-Jupiter HD 209458b. We consider three CMEs characterized by different velocities and densities, taking their parameters from typical CMEs observed for the Sun. The perturbations in the ram-pressure of the stellar wind during the passage of each CME tear off most of the envelope that is located beyond the Roche lobe. This leads to a substantial increase of the mass-loss rates during the interaction with the CME. We find that the mass lost by the planet during the whole crossing of a CME is of ≈10{sup 15} g, regardless of the CME taken into consideration. We also find that over the course of 1 Gyr, the mass lost by the planet because of CME impacts is comparable to that lost because of high-energy stellar irradiation.

  13. Influence of weight loss on the clinical manifestations of osteoarthritis of the knee-joints.

    Directory of Open Access Journals (Sweden)

    Inna Vladimirovna Solov'eva

    2014-10-01

    Full Text Available Obesity consistently associated with the development of a number of chronic diseases, leading to a decrease in quality of life, disability and death. The article examines the connection between obesity and disease of the musculoskeletal system, describes the mechanisms by means of which obesity leads to the development of osteoarthritis. It is evident that reduction of body mass can slow the progression of osteoporosis. The own experience of non-pharmacological and pharmacological treatment of obesity with the use of orlistat in 50 obese patients with osteoarthritis of the knee II–III stage is presented. Treatment has resulted in a decrease in body weight, waist circumference, accompanied by a decrease in symptoms osteoarthritis among all the patients. Our results showed that the addition of orlistat to standard osteoarthritis scheme leads to significant reduction in weight and reduction of clinical manifestations of osteoarthritis. According to the above, the drugs that have impact on weight loss, should be included in the treatment regimen of patients with osteoarthritis and obesity.

  14. Chronic sleep reduction, functioning at school and school achievement in preadolescents.

    Science.gov (United States)

    Meijer, Anne Marie

    2008-12-01

    This study investigates the relationship between chronic sleep reduction, functioning at school and school achievement of boys and girls. To establish individual consequences of chronic sleep reduction (tiredness, sleepiness, loss of energy and emotional instability) the Chronic Sleep Reduction Questionnaire has been developed. A total of 436 children (219 boys, 216 girls, 1 [corrected] missing; mean age = 11 years and 5 months) from the seventh and eight grades of 12 elementary schools participated in this study. The inter-item reliability (Cronbach's alpha = 0.84) and test-retest reliability (r = 0.78) of the Chronic Sleep Reduction Questionnaire were satisfactory. The construct validity of the questionnaire as measured by a confirmative factor analysis was acceptable as well (CMIN/DF = 1.49; CFI = 0.94; RMSEA = 0.034). Cronbach's alpha's of the scales measuring functioning at school (teacher's influence, self-image as pupil, and achievement motivation) were 0.69, 0.86 and 0.79. School achievement was based on self-reported marks concerning six school subjects. To test the models concerning the relations of chronic sleep reduction, functioning at school, and school achievement, the covariance matrix of these variables were analysed by means of structural equation modelling. To test for differences between boys and girls a multi-group model is used. The models representing the relations between chronic sleep reduction - school achievement and chronic sleep reduction - functioning at school - school achievement fitted the data quite well. The impact of chronic sleep reduction on school achievement and functioning at school appeared to be different for boys and girls. Based on the results of this study, it may be concluded that chronic sleep reduction may affect school achievement directly and indirectly via functioning at school, with worse school marks as a consequence.

  15. Pediatric sleep apnea

    Science.gov (United States)

    Sleep apnea - pediatric; Apnea - pediatric sleep apnea syndrome; Sleep-disordered breathing - pediatric ... Untreated pediatric sleep apnea may lead to: High blood pressure Heart or lung problems Slow growth and development

  16. Changing your sleep habits

    Science.gov (United States)

    ... falling asleep; Sleep hygiene References American Academy of Sleep Medicine. Insomnia. Updated March 4, 2015. SleepEducation.org. sleepeducation. ... T, Dement WC, eds. Principles and Practice of Sleep Medicine . 6th ed. Philadelphia, PA: Elsevier; 2017:chap 86. ...

  17. Obstructive Sleep Apnoea

    African Journals Online (AJOL)

    Cheyne-Stokes respiration), obstructive sleep apnoea and mixed or complex sleep apnoea.1. Obstructive sleep apnoea (OSA) is the most common of these three disorders and is defined as airway obstruction during sleep, accompanied by at least ...

  18. Snoring and Sleep Apnea

    Science.gov (United States)

    ... Find an ENT Doctor Near You Snoring and Sleep Apnea Snoring and Sleep Apnea Patient Health Information ... newsroom@entnet.org . Insight into sleeping disorders and sleep apnea Forty-five percent of normal adults snore ...

  19. Influence of marital status and employment status on long-term adherence with continuous positive airway pressure in sleep apnea patients.

    Science.gov (United States)

    Gagnadoux, Frédéric; Le Vaillant, Marc; Goupil, François; Pigeanne, Thierry; Chollet, Sylvaine; Masson, Philippe; Humeau, Marie-Pierre; Bizieux-Thaminy, Acya; Meslier, Nicole

    2011-01-01

    Long-term adherence is a major issue in patients receiving home continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea-hypopnea syndrome (OSAHS). In a multicenter prospective cohort (the Institut de Recherche en Santé Respiratoire des Pays de la Loire [IRSR] sleep cohort) of consecutive OSAHS patients in whom CPAP had been prescribed for at least 90 days, we studied the impact on long-term treatment adherence of socioeconomic factors, patients and disease characteristics prior to CPAP initiation. Among 1,141 patients in whom CPAP had been prescribed for an average of 504±251 days (range: 91 to 1035), 674 (59%) were adherent with a mean daily use of CPAP≥4 h (mean: 6.42±1.35 h). Stepwise regression analysis identified 4 independent factors of CPAP adherence including apnea-hypopnea index (AHI) (OR: 1.549, 95%CI 1.163 to 2.062 for AHI≥30 vs. AHIstatus (OR: 1.414, 95%CI 1.097-1.821 for retired vs. employed; p = 0.007) and marital status (OR: 1.482, 95%CI 1.088-2.019 for married or living as a couple vs. living alone; p = 0.01). Age, gender, Epworth sleepiness scale, depressive syndrome, associated cardiovascular morbidities, educational attainment and occupation category did not influence CPAP adherence. Marital status and employment status are independent factors of CPAP adherence in addition to BMI and disease severity. Patients living alone and/or working patients are at greater risk of non-adherence, whereas adherence is higher in married and retired patients. These findings suggest that the social context of daily life should be taken into account in risk screening for CPAP non-adherence. Future interventional studies targeting at-risk patients should be designed to address social motivating factors and work-related barriers to CPAP adherence.

  20. A loss of function analysis of host factors influencing Vaccinia virus replication by RNA interference.

    Directory of Open Access Journals (Sweden)

    Philippa M Beard

    Full Text Available Vaccinia virus (VACV is a large, cytoplasmic, double-stranded DNA virus that requires complex interactions with host proteins in order to replicate. To explore these interactions a functional high throughput small interfering RNA (siRNA screen targeting 6719 druggable cellular genes was undertaken to identify host factors (HF influencing the replication and spread of an eGFP-tagged VACV. The experimental design incorporated a low multiplicity of infection, thereby enhancing detection of cellular proteins involved in cell-to-cell spread of VACV. The screen revealed 153 pro- and 149 anti-viral HFs that strongly influenced VACV replication. These HFs were investigated further by comparisons with transcriptional profiling data sets and HFs identified in RNAi screens of other viruses. In addition, functional and pathway analysis of the entire screen was carried out to highlight cellular mechanisms involved in VACV replication. This revealed, as anticipated, that many pro-viral HFs are involved in translation of mRNA and, unexpectedly, suggested that a range of proteins involved in cellular transcriptional processes and several DNA repair pathways possess anti-viral activity. Multiple components of the AMPK complex were found to act as pro-viral HFs, while several septins, a group of highly conserved GTP binding proteins with a role in sequestering intracellular bacteria, were identified as strong anti-viral VACV HFs. This screen has identified novel and previously unexplored roles for cellular factors in poxvirus replication. This advancement in our understanding of the VACV life cycle provides a reliable knowledge base for the improvement of poxvirus-based vaccine vectors and development of anti-viral theraputics.

  1. The influence of mood on the perception of hearing-loss related quality of life in people with hearing loss and their significant others.

    Science.gov (United States)

    Preminger, Jill E; Meeks, Suzanne

    2010-04-01

    The purpose of this research was to investigate the congruent/incongruent perceptions of hearing-loss related quality of life between members of couples and to determine how incongruence was affected by individual psychosocial characteristics, specifically measures of mood (negative affect and positive affect), stress, and communication in the marriage. An exploratory correlational analysis was performed on data for 52 couples in which only one member had a hearing loss. In the regression analyses the independent variables were hearing-loss related quality of life scores measured in people with hearing loss, measured in significant others, and differences in hearing-loss related quality of life among members of a couple. The results demonstrate that both in people with hearing loss and their significant others, perceptions of hearing-loss related quality of life is highly correlated with negative mood scores. Incongruence in hearing-loss related quality of life scores reported by members of a couple were highly correlated with negative affect measured within each individual. Future research evaluating the effectiveness of audiologic rehabilitation can use measures of mood as an outcome variable.

  2. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    International Nuclear Information System (INIS)

    Rack, Michael Thomas

    2014-01-01

    losses in the presence of resonant magnetic perturbation fields, is presented. It is used to investigate the impact of various types of perturbation field, static and rotating, on the losses. The investigations of the heat load deposition profiles show important features of the resonant magnetic perturbation fields. Firstly, the heat can be favourably redistributed to reduce the local heat fluxes; secondly, a physical process is observed that appears to be linked to the heat redistribution and causes a slow propagation of a heat flux pattern long before the major energy is ejected. This opens a new view on the physics of resonant magnetic perturbation fields as it shows that processes on different time-scales are involved during the control of the plasma edge instabilities. The control of these instabilities can benefit from the new method of applying resonant magnetic perturbation fields using lower hybrid waves. This method provides high flexibility as needed to optimize the heat load redistribution. It is proven to create perturbation fields that are always resonant in the plasma edge region. In addition, it was found that no clear drawbacks appear over a wide range of perturbation fields; moreover, strong indications for an improvement of the fast ion confinement are seen. The overall results provide a positive outlook for the application of resonant magnetic perturbation fields to control edge instabilities: (a) an advantageous redistribution of transient heat loads is achievable, (b) lower hybrid waves can be used for the production of highly flexible resonant magnetic perturbation fields, and (c) resonant magnetic perturbation fields do not necessarily reduce the fast ion confinement. These results show that an optimization of the applied magnetic perturbation fields is able to solve the problem of transient heat loads without any drawbacks for the crucial fast ion confinement.

  3. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael Thomas

    2014-07-11

    losses in the presence of resonant magnetic perturbation fields, is presented. It is used to investigate the impact of various types of perturbation field, static and rotating, on the losses. The investigations of the heat load deposition profiles show important features of the resonant magnetic perturbation fields. Firstly, the heat can be favourably redistributed to reduce the local heat fluxes; secondly, a physical process is observed that appears to be linked to the heat redistribution and causes a slow propagation of a heat flux pattern long before the major energy is ejected. This opens a new view on the physics of resonant magnetic perturbation fields as it shows that processes on different time-scales are involved during the control of the plasma edge instabilities. The control of these instabilities can benefit from the new method of applying resonant magnetic perturbation fields using lower hybrid waves. This method provides high flexibility as needed to optimize the heat load redistribution. It is proven to create perturbation fields that are always resonant in the plasma edge region. In addition, it was found that no clear drawbacks appear over a wide range of perturbation fields; moreover, strong indications for an improvement of the fast ion confinement are seen. The overall results provide a positive outlook for the application of resonant magnetic perturbation fields to control edge instabilities: (a) an advantageous redistribution of transient heat loads is achievable, (b) lower hybrid waves can be used for the production of highly flexible resonant magnetic perturbation fields, and (c) resonant magnetic perturbation fields do not necessarily reduce the fast ion confinement. These results show that an optimization of the applied magnetic perturbation fields is able to solve the problem of transient heat loads without any drawbacks for the crucial fast ion confinement.

  4. Sleep patterns of Japanese preschool children and their parents: implications for co-sleeping.

    Science.gov (United States)

    Iwata, Sachiko; Iwata, Osuke; Matsuishi, Toyojiro

    2013-06-01

    The aim of this study was to investigate the direct relationship of sleep schedule and sleep quality variables between healthy preschool children and their parents, focusing on the influence of the difference in bedtime between each other. Forty-seven Japanese 5-year-old children and their primary parent were studied. The parents completed questionnaires including the Epworth Sleepiness Scale and Pittsburgh Sleep Quality Index. The children wore an actigraph for one week. Although sleep patterns of children were generally independent of their parents, late sleep end time and bedtime of children were associated with parents' late sleep end time on weekends. For 87% of children and parents who shared a bedroom, sleep quality was negatively affected by a shorter difference in bedtimes between child and parent, but not by co-sleeping. Sleep behaviours of parents can influence those of their children. For parents and children who share a bedroom, the timing of bedtime rather than co-sleeping may be a key factor in modulating sleep patterns. Trying to get children asleep and subsequently falling asleep at a similar time may disturb parents' sleep quality, which may subsequently affect that of their children. ©2013 Foundation Acta Paediatrica. Published by Blackwell Publishing Ltd.

  5. Can intradermal administration of angiotensin II influence human heat loss responses during whole body heat stress?

    Science.gov (United States)

    Fujii, Naoto; Meade, Robert D; Paull, Gabrielle; McGinn, Ryan; Foudil-bey, Imane; Akbari, Pegah; Kenny, Glen P

    2015-05-01

    It is unclear if angiotensin II, which can increase the production of reactive oxygen species (oxidative stress), modulates heat loss responses of cutaneous blood flow and sweating. We tested the hypothesis that angiotensin II-induced increases in oxidative stress impair cutaneous perfusion and sweating during rest and exercise in the heat. Eleven young (24 ± 4 yr) healthy adults performed two 30-min cycling bouts at a fixed rate of metabolic heat production (400 W) in the heat (35°C). The first and second exercises were followed by a 20- and 40-min recovery. Four microdialysis fibers were placed in the forearm skin for continuous administration of either: 1) lactated Ringer (control), 2) 10 μM angiotensin II, 3) 10 mM ascorbate (an antioxidant), or 4) a combination of 10 μM angiotensin II + 10 mM ascorbate. Cutaneous vascular conductance (CVC; laser-Doppler perfusion units/mean arterial pressure) and sweating (ventilated capsule) were evaluated at each skin site. Compared with control, angiotensin II reduced both CVC and sweating at baseline resting and during each recovery in the heat (all P 0.05). When ascorbate was coinfused with angiotensin II, the effect of angiotensin II on sweating was abolished (all P > 0.05); however, its effect on CVC at baseline resting and during each recovery remained intact (all P stress, while it impairs sweating through increasing oxidative stress during exposure to an ambient heat stress before and following exercise. Copyright © 2015 the American Physiological Society.

  6. Sleep in Othello

    Science.gov (United States)

    Dimsdale, Joel E.

    2009-01-01

    Some of our best descriptions of sleep disorders come from literature. While Shakespeare is well known for his references to insomnia and sleep walking, his works also demonstrate a keen awareness of many other sleep disorders. This paper examines sleep themes in Shakespeare's play Othello. The play indicates Shakespeare's astute eye for sleep deprivation, sexual parasomnias, and effects of stress and drugs on sleep. Citation: Dimsdale JE. Sleep in Othello. J Clin Sleep Med 2009;5(3):280-281. PMID:19960651

  7. Sleep Tips: 7 Steps to Better Sleep

    Science.gov (United States)

    ... turn every night. Consider simple tips for better sleep, from setting a sleep schedule to including physical activity in your daily ... factors that can interfere with a good night's sleep — from work stress and family responsibilities to unexpected ...

  8. Influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation

    Directory of Open Access Journals (Sweden)

    Sladojević Ž.

    2013-01-01

    Full Text Available The objective of this work was to investigate the influence of housing conditions, number of farrowing and number of pigs in litter on weight loss in sows during lactation. The experiment included 60 sows, half breed developed by cross breeding of Big Yorkshire and Swedish Landrace in lactation. Body weight of the sows (kg was determined 2nd, 7th, 14th, 21st and 28th day after farrowing. On the basis of the obtained values, there was calculated the difference in body weight between two consecutive investigation periods. The sows were divided into two groups and held in different housing conditions: 30 of them were held in extensive, and other 30 sows in intensive way of farming. In regard to number of farrowing, the sows were divided into three groups: sows with one or two farrowing (group P1, n=20, with three or four farrowing (group P2, n=20, and sows that farrowed five or more times (P3,n=20. In regard to number of pigs in litter, the sows were divided into two groups: the first (Group I, n=30 with sows that had up to eight pigs, and the second (Group II, n=30 with sows that had nine or more pigs in litter. The obtained results showed that in all perids of the investigation during lactation, body weight in sows held in extensive farming conditions was statistically significantly higher compared to those from intensive farming conditions. On the other hand, the loss of body weight during lactation was significantly higher in sows from extensive in regard to intensive farming conditions in the first two weeks of lactation. The sows with bigger number of farrowing had greater body weight, compared to those with smaller number of farrowing. There was no statistically significant difference in body weight loss during lactation, between sows with different number of farrowing, but considering that the sows with less farrowings had significantly lower body weight, they consequently lost more weight in percentage. The sows with greater number of pigs

  9. Blood RNA biomarkers in prodromal PARK4 and rapid eye movement sleep behavior disorder show role of complexin 1 loss for risk of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Suna Lahut

    2017-05-01

    Full Text Available Parkinson's disease (PD is a frequent neurodegenerative process in old age. Accumulation and aggregation of the lipid-binding SNARE complex component α-synuclein (SNCA underlies this vulnerability and defines stages of disease progression. Determinants of SNCA levels and mechanisms of SNCA neurotoxicity have been intensely investigated. In view of the physiological roles of SNCA in blood to modulate vesicle release, we studied blood samples from a new large pedigree with SNCA gene duplication (PARK4 mutation to identify effects of SNCA gain of function as potential disease biomarkers. Downregulation of complexin 1 (CPLX1 mRNA was correlated with genotype, but the expression of other Parkinson's disease genes was not. In global RNA-seq profiling of blood from presymptomatic PARK4 indviduals, bioinformatics detected significant upregulations for platelet activation, hemostasis, lipoproteins, endocytosis, lysosome, cytokine, Toll-like receptor signaling and extracellular pathways. In PARK4 platelets, stimulus-triggered degranulation was impaired. Strong SPP1, GZMH and PLTP mRNA upregulations were validated in PARK4. When analysing individuals with rapid eye movement sleep behavior disorder, the most specific known prodromal stage of general PD, only blood CPLX1 levels were altered. Validation experiments confirmed an in