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Sample records for randomly disturbed visuo-manual

  1. Visuo-manual tracking: does intermittent control with aperiodic sampling explain linear power and non-linear remnant without sensorimotor noise?

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    Gollee, Henrik; Gawthrop, Peter J; Lakie, Martin; Loram, Ian D

    2017-11-01

    ways) manually controlled two systems (1st and 2nd order) subject to a periodic multi-sine disturbance. Joystick power was analysed using three models, continuous-linear-control (CC), continuous-linear-control with calculated noise spectrum (CCN), and intermittent control with aperiodic sampling triggered by prediction error thresholds (IC). Unlike the linear mechanism, the intermittent control mechanism explained the majority of total power (linear and remnant) (77-87% vs. 8-48%, IC vs. CC). Between conditions, IC used thresholds and distributions of open loop intervals consistent with, respectively, instructions and previous measured, model independent values; whereas CCN required changes in noise spectrum deviating from broadband, signal dependent noise. We conclude that manual tracking uses open loop predictive control with aperiodic sampling. Because aperiodic sampling is inherent to serial decision making within previously identified, specific frontal, striatal and parietal networks we suggest that these structures are intimately involved in visuo-manual tracking. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

  2. Bifurcation and chaos response of a cracked rotor with random disturbance

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    Leng, Xiaolei; Meng, Guang; Zhang, Tao; Fang, Tong

    2007-01-01

    The Monte-Carlo method is used to investigate the bifurcation and chaos characteristics of a cracked rotor with a white noise process as its random disturbance. Special attention is paid to the influence of the stiffness change ratio and the rotating speed ratio on the bifurcation and chaos response of the system. Numerical simulations show that the affect of the random disturbance is significant as the undisturbed response of the cracked rotor system is a quasi-periodic or chaos one, and such affect is smaller as the undisturbed response is a periodic one.

  3. Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

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    Fengjiao Wu

    2016-01-01

    Full Text Available The robust fuzzy control for fractional-order hydroturbine regulating system is studied in this paper. First, the more practical fractional-order hydroturbine regulating system with uncertain parameters and random disturbances is presented. Then, on the basis of interval matrix theory and fractional-order stability theorem, a fuzzy control method is proposed for fractional-order hydroturbine regulating system, and the stability condition is expressed as a group of linear matrix inequalities. Furthermore, the proposed method has good robustness which can process external random disturbances and uncertain parameters. Finally, the validity and superiority are proved by the numerical simulations.

  4. Music therapy for mood disturbance during hospitalization for autologous stem cell transplantation: a randomized controlled trial.

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    Cassileth, Barrie R; Vickers, Andrew J; Magill, Lucanne A

    2003-12-15

    High-dose therapy with autologous stem cell transplantation (HDT/ASCT) is a commonly used treatment for hematologic malignancies. The procedure causes significant psychological distress and no interventions have been demonstrated to improve mood in these patients. Music therapy has been shown to improve anxiety in a variety of acute medical settings. In the current study, the authors determined the effects of music therapy compared with standard care on mood during inpatient stays for HDT/ASCT. Patients with hematologic malignancy admitted for HDT/ASCT at two sites (Memorial Sloan-Kettering Cancer Center and Ireland Cancer Center in Cleveland, Ohio) were randomized to receive music therapy given by trained music therapists or standard care. Outcome was assessed at baseline and every 3 days after randomization using the Profile of Mood States. Of 69 patients registered in the study, follow-up data were available for 62 (90%). During their inpatient stay, patients in the music therapy group scored 28% lower on the combined Anxiety/Depression scale (P = 0.065) and 37% lower (P = 0.01) on the total mood disturbance score compared with controls. Music therapy is a noninvasive and inexpensive intervention that appears to reduce mood disturbance in patients undergoing HDT/ASCT. Copyright 2003 American Cancer Society.

  5. Physiotherapy for sleep disturbance in people with chronic low back pain: results of a feasibility randomized controlled trial

    NARCIS (Netherlands)

    Eadie, J.; van de Water, A.T.; Lonsdale, C.; Tully, M.A.; van Mechelen, W.; Boreham, C.A.; Daly, L.; McDonough, S.M.; Hurley, D.A.

    2013-01-01

    Objective: To determine the feasibility of a randomized controlled trial investigating the effectiveness of physiotherapy for sleep disturbance in chronic low back pain (CLBP) (≥12wks). Design: Randomized controlled trial with evaluations at baseline, 3 months, and 6 months. Setting: Outpatient

  6. Melatonin Supplementation for Children With Atopic Dermatitis and Sleep Disturbance: A Randomized Clinical Trial.

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    Chang, Yung-Sen; Lin, Ming-Hung; Lee, Jyh-Hong; Lee, Pei-Lin; Dai, Yang-Shia; Chu, Kuan-Hua; Sun, Chi; Lin, Yu-Tsan; Wang, Li-Chieh; Yu, Hsin-Hui; Yang, Yao-Hsu; Chen, Chun-An; Wan, Kong-Sang; Chiang, Bor-Luen

    2016-01-01

    Sleep disturbance is common in children with atopic dermatitis (AD), but effective clinical management for this problem is lacking. Reduced levels of nocturnal melatonin were found to be associated with sleep disturbance and increased disease severity in children with AD. Melatonin also has sleep-inducing and anti-inflammatory properties and therefore might be useful for the management of AD. To evaluate the effectiveness of melatonin supplementation for improving the sleep disturbance and severity of disease in children with AD. This randomized clinical trial used a double-blind, placebo-controlled crossover design to study 73 children and adolescents aged 1 to 18 years with physician-diagnosed AD involving at least 5% of the total body surface area. The study was conducted at the pediatric department of a large tertiary care hospital in Taiwan from August 1, 2012, through January 31, 2013. Forty-eight children were randomized 1:1 to melatonin or placebo treatment, and 38 of these (79%) completed the cross-over period of the trial. Final follow-up occurred on April 13, 2013, and data were analyzed from January 27 to April 25, 2014. Analyses were based on intention to treat. Melatonin, 3 mg/d, or placebo for 4 weeks followed by a 2-week washout period and then crossover to the alternate treatment for 4 weeks. The primary outcome was AD severity evaluated using the Scoring Atopic Dermatitis (SCORAD) index, with scores ranging from 0 to 103 and greater scores indicating worse symptoms. Secondary outcomes included sleep variables measured by actigraphy, subjective change in sleep and dermatitis, sleep variables measured by polysomnography, nocturnal urinary levels of 6-sulfatoxymelatonin, and serum IgE levels. After melatonin treatment among the 48 children included in the study, the SCORAD index decreased by 9.1 compared with after placebo (95% CI, -13.7 to -4.6; P sleep-onset latency shortened by 21.4 minutes after melatonin treatment compared with after placebo

  7. Mindfulness-based intervention for prodromal sleep disturbances in older adults: design and methodology of a randomized controlled trial.

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    Black, David S; O'Reilly, Gillian A; Olmstead, Richard; Breen, Elizabeth C; Irwin, Michael R

    2014-09-01

    Sleep problems are prevalent among older adults, often persist untreated, and are predictive of health detriments. Given the limitations of conventional treatments, non-pharmacological treatments such as mindfulness-based interventions (MBIs) are gaining popularity for sleep ailments. However, nothing is yet known about the impact of MBIs on sleep in older adults with prodromal sleep disturbances. This article details the design and methodology of a 6-week parallel-group RCT calibrated to test the treatment effect of the Mindful Awareness Practices (MAPs) program versus sleep hygiene education for improving sleep quality, as the main outcome, in older adults with prodromal sleep disturbances. Older adults with current sleep disturbances will be recruited from the urban Los Angeles community. Participants will be randomized into two standardized treatment conditions, MAPs and sleep hygiene education. Each condition will consist of weekly 2-hour group-based classes over the course of the 6-week intervention. The primary objective of this study is to determine if mindfulness meditation practice as engaged through the MAPs program leads to improved sleep quality relative to sleep hygiene education in older adults with prodromal sleep disturbances. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Effects of music and music video interventions on sleep quality: A randomized controlled trial in adults with sleep disturbances.

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    Huang, Chiung-Yu; Chang, En-Ting; Hsieh, Yuan-Mei; Lai, Hui-Ling

    2017-10-01

    The present study aimed to compare the effects of music and music video interventions on objective and subjective sleep quality in adults with sleep disturbances. A randomized controlled trial was performed on 71 adults who were recruited from the outpatient department of a hospital with 1100 beds and randomly assigned to the control, music, and music video groups. During the 4 test days (Days 2-5), for 30min before nocturnal sleep, the music group listened to Buddhist music and the music video group watched Buddhist music videos. They were instructed to not listen/watch to the music/MV on the first night (pretest, Day 1) and the final night (Day 6). The control group received no intervention. Sleep was assessed using a one-channel electroencephalography machine in their homes and self-reported questionnaires. The music and music video interventions had no effect on any objective sleep parameters, as measured using electroencephalography. However, the music group had significantly longer subjective total sleep time than the music video group did (Wald χ 2 =6.23, p=0.04). Our study results increase knowledge regarding music interventions for sleep quality in adults with sleep disturbances. This study suggested that more research is required to strengthen the scientific knowledge of the effects of music intervention on sleep quality in adults with sleep disturbances. (ISRCTN94971645). Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Mindfulness meditation and improvement in sleep quality and daytime impairment among older adults with sleep disturbances: a randomized clinical trial.

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    Black, David S; O'Reilly, Gillian A; Olmstead, Richard; Breen, Elizabeth C; Irwin, Michael R

    2015-04-01

    Sleep disturbances are most prevalent among older adults and often go untreated. Treatment options for sleep disturbances remain limited, and there is a need for community-accessible programs that can improve sleep. To determine the efficacy of a mind-body medicine intervention, called mindfulness meditation, to promote sleep quality in older adults with moderate sleep disturbances. Randomized clinical trial with 2 parallel groups conducted from January 1 to December 31, 2012, at a medical research center among an older adult sample (mean [SD] age, 66.3 [7.4] years) with moderate sleep disturbances (Pittsburgh Sleep Quality Index [PSQI] >5). A standardized mindful awareness practices (MAPs) intervention (n = 24) or a sleep hygiene education (SHE) intervention (n = 25) was randomized to participants, who received a 6-week intervention (2 hours per week) with assigned homework. The study was powered to detect between-group differences in moderate sleep disturbance measured via the PSQI at postintervention. Secondary outcomes pertained to sleep-related daytime impairment and included validated measures of insomnia symptoms, depression, anxiety, stress, and fatigue, as well as inflammatory signaling via nuclear factor (NF)-κB. Using an intent-to-treat analysis, participants in the MAPs group showed significant improvement relative to those in the SHE group on the PSQI. With the MAPs intervention, the mean (SD) PSQIs were 10.2 (1.7) at baseline and 7.4 (1.9) at postintervention. With the SHE intervention, the mean (SD) PSQIs were 10.2 (1.8) at baseline and 9.1 (2.0) at postintervention. The between-group mean difference was 1.8 (95% CI, 0.6-2.9), with an effect size of 0.89. The MAPs group showed significant improvement relative to the SHE group on secondary health outcomes of insomnia symptoms, depression symptoms, fatigue interference, and fatigue severity (P anxiety, stress, or NF-κB, although NF-κB concentrations significantly declined over time in both groups (P

  10. A randomized controlled trial of a home hospital intervention for frail elderly demented patients: behavioral disturbances and caregiver's stress.

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    Tibaldi, V; Aimonino, N; Ponzetto, M; Stasi, M F; Amati, D; Raspo, S; Roglia, D; Molaschi, M; Fabris, F

    2004-01-01

    A Geriatric Home Hospitalization Service (GHHS) has been operating in Torino at S. Giovanni Battista Hospital since 1985. GHHS allows us to perform diagnostic and therapeutic interventions, which are usually made in hospital, also at home. GHHS team includes geriatricians, nurses, physiotherapists, social workers and counselors. Between February 1999 and April 2002, the GHH Service conducted a randomized controlled trial on 109 elderly, demented patients requiring admission to the Hospital Emergency Department (ED)for acute illnesses. Objective of the study was to identify the benefits of the care in a GHHScompared to a general medical ward (GMW) in reducing behavioral disturbances in elderly patients with advanced dementia and in lowering caregiver's stress. Patients were randomly assigned to GHHS (56 patients) or to GMW (53 patients). Both groups were examined using the same protocol and were evaluated on admission and on discharge. All patients had a severe form of dementia as shown by the clinical dementia rating (CDR) scale mean value (3.7 +/- 0.9) with an important functional impairment and a relevant degree of comorbidity.The main reasons for hospitalization were infections, cerebrovascular accidents and malnutrition. Mortality of total sample was 19.3 %, without significant differences in the two settings of care. On discharge, in GHHS patients there was a significant reduction of behavioral disturbances. The use of anti-psychotic drugs was significantly lower in GHHS patients compared to the GMW group (p < 0.001). The stress of caregivers on discharge was reduced only in GHHS group and not in the control ones. In conclusion, we can say that a GHHS continuous support allows us to reduce the family caregiver's stress. When treated at home, demented patients do not have to change their environment or routine and it is possible to have a better control on behavioral disturbances.

  11. Cognitive Behavior Therapy to Treat Sleep Disturbance and Fatigue After Traumatic Brain Injury: A Pilot Randomized Controlled Trial.

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    Nguyen, Sylvia; McKay, Adam; Wong, Dana; Rajaratnam, Shantha M; Spitz, Gershon; Williams, Gavin; Mansfield, Darren; Ponsford, Jennie L

    2017-08-01

    To evaluate the efficacy of adapted cognitive behavioral therapy (CBT) for sleep disturbance and fatigue in individuals with traumatic brain injury (TBI). Parallel 2-group randomized controlled trial. Outpatient therapy. Adults (N=24) with history of TBI and clinically significant sleep and/or fatigue complaints were randomly allocated to an 8-session adapted CBT intervention or a treatment as usual (TAU) condition. Cognitive behavior therapy. The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) posttreatment and at 2-month follow-up. Secondary measures included the Insomnia Severity Index, Fatigue Severity Scale, Brief Fatigue Inventory (BFI), Epworth Sleepiness Scale, and Hospital Anxiety and Depression Scale. At follow-up, CBT recipients reported better sleep quality than those receiving TAU (PSQI mean difference, 4.85; 95% confidence interval [CI], 2.56-7.14). Daily fatigue levels were significantly reduced in the CBT group (BFI difference, 1.54; 95% CI, 0.66-2.42). Secondary improvements were significant for depression. Large within-group effect sizes were evident across measures (Hedges g=1.14-1.93), with maintenance of gains 2 months after therapy cessation. Adapted CBT produced greater and sustained improvements in sleep, daily fatigue levels, and depression compared with TAU. These pilot findings suggest that CBT is a promising treatment for sleep disturbance and fatigue after TBI. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  12. Tetrahydrocannabinol in Behavioral Disturbances in Dementia: A Crossover Randomized Controlled Trial.

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    van den Elsen, Geke A H; Ahmed, Amir I A; Verkes, Robbert-Jan; Feuth, Ton; van der Marck, Marjolein A; Olde Rikkert, Marcel G M

    2015-12-01

    Neuropsychiatric symptoms (NPS) are highly prevalent in dementia, but effective pharmacotherapy without important side effects is lacking. This study aims to assess the efficacy and safety of oral tetrahydrocannabinol (THC) in the treatment of NPS in dementia. Randomized, double-blind, placebo-controlled, repeated crossover trial, consisting of six treatment blocks of 2 weeks each. Two hospital sites in The Netherlands, September 2011 to December 2013. Patients with dementia and clinically relevant NPS. Within each block THC (0.75 mg twice daily in blocks 1-3 and 1.5 mg twice daily in blocks 4-6) and placebo were administered in random order for 3 consecutive days, followed by a 4-day washout. Primary outcome was change in Neuropsychiatric Inventory (NPI) score. Analyses were performed intention-to-treat. Data from all subjects were used without imputation. Sample size required for a power of 80% was 20 patients, because of repeated crossover. 22 patients (15 men, mean age 76.4 [5.3] years) were included, of whom 20 (91%) completed the trial. THC did not reduce NPI compared to placebo (blocks 1-3: 1.8, 97.5% CI: -2.1 to 5.8; blocks 4-6: -2.8, 97.5% CI: -7.4 to 1.8). THC was well tolerated, as assessed by adverse event monitoring, vital signs, and mobility. The incidence of adverse events was similar between treatment groups. Four non-related serious adverse events occurred. This is the largest randomized controlled trial studying the efficacy of THC for NPS, to date. Oral THC did not reduce NPS in dementia, but was well tolerated by these vulnerable patients, supporting future higher dosing studies. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  13. Evaluation of the effects of extended release quetiapine fumarate monotherapy on sleep disturbance in patients with major depressive disorder: a pooled analysis of four randomized acute studies.

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    Trivedi, Madhukar H; Bandelow, Borwin; Demyttenaere, Koen; Papakostas, George I; Papakosts, George I; Szamosi, Johan; Earley, Willie; Eriksson, Hans

    2013-09-01

    Effects of once-daily extended-release quetiapine fumarate (quetiapine XR) monotherapy on sleep quality and disturbance in patients with major depressive disorder (MDD) were evaluated. Pooled data from four 6- or 8-wk placebo-controlled quetiapine XR (50-300 mg/d) monotherapy studies (D1448C00001; D1448C00002; D1448C00003; D1448C00004) were analysed. Primary efficacy end-point was change from randomization in Montgomery Åsberg Depression Rating Scale (MADRS) score. Post hoc analyses of secondary end-points were conducted for change from randomization in: MADRS item 4 (reduced sleep); Hamilton Rating Scale for Depression (HAMD) items 4 (insomnia-early), 5 (insomnia-middle), 6 (insomnia-late) and sleep disturbance factor (items 4 + 5+6) scores; Pittsburgh Sleep Quality Index (PSQI) global scores. MADRS total score change was also evaluated in patients experiencing high and low baseline sleep disturbance (HAMD sleep disturbance factor scores ⩾4 and sleep disturbance factor score and PSQI global scores from baseline vs. placebo (p sleep disturbance (n = 865, quetiapine XR; n = 514, placebo), quetiapine XR improved MADRS total score vs. placebo at all visits (p sleep disturbance (n = 252, quetiapine XR; n = 121, placebo), quetiapine XR improved MADRS total score vs. placebo at weeks 2 (p sleep disturbance vs. placebo in patients with MDD, including those with either high or low baseline sleep disturbance levels.

  14. Individualized Cognition-Action intervention to prevent behavioral disturbances and functional decline in institutionalized older adults: a randomized pilot trial.

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    Dechamps, Arnaud; Alban, Rigier; Jen, Joanne; Decamps, Arnaud; Traissac, Thalie; Dehail, Patrick

    2010-08-01

    To evaluate the effectiveness of an individualized Cognition-Action (CA) intervention to reduce behavioral disturbances in severely deconditioned institutionalized old adults. 12 weeks randomized pilot trial of either individualized Cognition-Action program (n = 24) or routine medical care as control (C, n = 25). Long-term care (LTC) of the Geriatric Department from the University State Hospital in Bordeaux, France. 49 institutionalized old patients with at least one Neuropsychiatric symptoms > or =4. The CA rationale was a non-preconceived ideas approach over the patient's abilities and discourse. Patients received short bouts of 5-15 min and accumulated 50 min of interaction per week. CA intervention used five standardized exercises as tools to enhance communication and social interactions. CA was compared to usual care. Primary outcomes were the Neuropsychiatric inventory (NPI) total and symptoms scores. Secondary outcomes were the BERG balance scale, the Geriatric Depression Scale (GDS), Quality of life AM-PAC-CAT and Muscle strength. The CA group had a clinically significant NPI total score reduction compared to C, -7, 95%CI [-10.8 to -3], eta2 = 0.24. CA group showed a risk reduction of NPI total score worsening, OR = 0.09, 95%CI [0.02-0.37]. BERG total score was clinically improved in the CA group compared to C, 4.9 95%CI [0.7-9.2], eta2(p)= 0.11. CA patients reduced their GDS score and improved their Quality of life and Strength. The combination of tailored guidance and simple standardized exercises was an effective behavioral management approach for behavioral disturbances reduction and functional autonomy improvement in institutionalized old adult populations.

  15. Comparative effectiveness of electro-acupuncture versus gabapentin for sleep disturbances in breast cancer survivors with hot flashes: a randomized trial.

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    Garland, Sheila N; Xie, Sharon X; Li, Qing; Seluzicki, Christina; Basal, Coby; Mao, Jun J

    2017-05-01

    Sleep disturbance is a major consequence of hot flashes among breast cancer survivors. This study evaluated the effects of electro-acupuncture (EA) versus gabapentin (GP) for sleep disturbances among breast cancer survivors experiencing daily hot flashes. We analyzed data from a randomized controlled trial involving 58 breast cancer survivors experiencing bothersome hot flashes at least two times per day. Participants were randomly assigned to receive 8 weeks of EA or daily GP (total dose of 900 mg/d). The primary outcome was change in the total Pittsburgh Sleep Quality Index (PSQI) score between groups at week 8. Secondary outcomes include specific PSQI domains. By the end of treatment at week 8, the mean reduction in PSQI total score was significantly greater in the EA group than the GP group (-2.6 vs -0.8, P = 0.044). The EA also had improved sleep latency (-0.5 vs 0.1, P = 0.041) and sleep efficiency (-0.6 vs 0.0, P = 0.05) compared with the GP group. By week 8, the EA group had improved sleep duration, less sleep disturbance, shorter sleep latency, decreased daytime dysfunction, improved sleep efficiency, and better sleep quality (P efficiency. Larger randomized controlled trials with longer follow-ups are needed to confirm this preliminary finding.

  16. Evaluation of the efficacy of randomized controlled trials of sensory stimulation interventions for sleeping disturbances in patients with dementia: a systematic review

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    Dimitriou TD

    2017-03-01

    Full Text Available Tatiana-Danai Dimitriou,1 Magdalini Tsolaki2 1Neuroscience Department, Medical School, Aristotle University of Thessaloniki, Thessaloniki, 2Third Department of Neurology, Aristotle University of Thessaloniki, Macedonia, Greece Objective: The current review aims to evaluate the sensory stimulation interventions in terms of reducing sleeping disturbances in patients with dementia. The nonpharmacological interventions seem to be an efficient, inexpensive, and easy tool for family caregivers. Moreover, sleeping disorders increase caregivers’ distress and may lead to hospitalization.Methods: A systematic literature search was performed. Eleven randomized controlled trials have been found. Among these eleven trials, one referred to massage therapy and acupuncture, and the other ten studies referred to bright light therapy.Results: The results demonstrated that there are no relevant randomized controlled trials of music therapy, aromatherapy, and multisensory environment/Snoezelen referring to sleeping disturbances. Several studies have been conducted about the effect of the bright light therapy, and there is also another study that combines massage therapy and acupuncture therapy.Conclusion: Sensory stimulation interventions are inexpensive and practical for dementia caregivers; however, only bright light therapy seems to be useful to reduce sleeping problems in dementia. The other sensory stimulation interventions lack evidence, and there is a strong need for further research. Keywords: sensory stimulation interventions, nonpharmacological interventions, sleeping disturbances, dementia, randomized controlled trials, review

  17. Randomized sham controlled trial of cranial microcurrent stimulation for symptoms of depression, anxiety, pain, fatigue and sleep disturbances in women receiving chemotherapy for early-stage breast cancer.

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    Lyon, Debra; Kelly, Debra; Walter, Jeanne; Bear, Harry; Thacker, Leroy; Elswick, Ronald K

    2015-01-01

    Women with breast cancer may experience symptoms of depression, anxiety, pain, fatigue and sleep disturbances during chemotherapy. However, there are few modalities that address multiple, commonly occurring symptoms that may occur in individuals receiving cancer treatment. Cranial electrical stimulation (CES) is a treatment that is FDA cleared for depression, anxiety and insomnia. CES is applied via electrodes placed on the ear that deliver pulsed, low amplitude electrical current to the head. This phase III randomized, sham-controlled study aimed to examine the effects of cranial microcurrent stimulation on symptoms of depression, anxiety, pain, fatigue, and sleep disturbances in women receiving chemotherapy for early-stage breast cancer. Patients were randomly assigned to either an actual or sham device and used the device daily for 1 h. The study was registered at clinicaltrials.gov, NCT00902330. The sample included N = 167 women with early-stage breast cancer. Symptom severity of depression, anxiety, and fatigue and sleep disturbances were generally mild to moderate. Levels of pain were low. Anxiety was highest prior to the initial chemotherapy and decreased over time. The primary outcome assessment (symptoms of depression, anxiety, fatigue, pain, sleep disturbances) revealed no statistically significant differences between the two groups, actual CES vs. sham. In this study, women receiving chemotherapy for breast cancer experienced multiple symptoms in the mild to moderate range. Although there is no evidence for the routine use of CES during the chemotherapy period for symptom management in women with breast cancer, further symptom management modalities should be evaluated to mitigate symptoms of depression, anxiety, fatigue, pain and sleep disturbances over the course of chemotherapy.

  18. Rapid resolution of sleep disturbances related to frequent reflux: effect of esomeprazole 20 mg in two randomized, double-blind, controlled trials.

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    Johnson, David A; Le Moigne, Anne; Hugo, Vincent; Nagy, Peter

    2015-02-01

    To investigate the resolution of heartburn and gastroesophageal reflux disease (GERD)-related sleep disturbances during the first 14 days of treatment with esomeprazole 20 mg compared to placebo in subjects with frequent nighttime heartburn and GERD-related sleep disturbances. This was a post hoc analysis of 2 week data from two previously published, similarly designed randomized, placebo-controlled trials of 4 weeks' duration comparing esomeprazole 20 mg, 40 mg (one study), and placebo. Inclusion and exclusion criteria for both trials were the same. NCT00628342; NCT00660660. The main outcome measures for this analysis were the resolution and/or relief of GERD-related sleep disturbances during 2 weeks of treatment with esomeprazole 20 mg or placebo. Resolution and/or relief of heartburn symptoms were also measured. In trial 1, 455 subjects were randomized, with 225 and 229 receiving esomeprazole 20 mg and placebo, respectively. In trial 2, 276 subjects were randomized, with 142 and 132 receiving esomeprazole and placebo, respectively. After 2 weeks, significantly more subjects who received esomeprazole 20 mg (50.5% [95% confidence interval: 43.8%-57.1%] and 39.4% [31.2%-47.6%] in trials 1 and 2, respectively) had resolution of sleep disturbances compared to placebo (19.9% [14.6%-25.2%] and 16.0% [9.6%-22.4%], respectively; p esomeprazole 20 mg was 1 day in both trials. After 2 weeks, significantly more subjects receiving esomeprazole 20 mg (32.3% [26.1%-38.5%] and 26.3% [18.9%-33.6%] in trials 1 and 2, respectively) had resolution of nighttime heartburn symptoms compared to placebo (5.4% [2.4%-8.4%] and 4.8% [1.1%-8.5%], respectively; p Esomeprazole 20 mg significantly and effectively reduced nighttime heartburn and GERD-related sleep disturbances in the first 2 weeks of treatment compared to placebo, with rapid resolution of sleep disturbances in the first days of treatment.

  19. Clinical Efficacy of Traditional Chinese Medicine, Suan Zao Ren Tang, for Sleep Disturbance during Methadone Maintenance: A Randomized, Double-Blind, Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Yuan-Yu Chan

    2015-01-01

    Full Text Available Methadone maintenance therapy is an effective treatment for opiate dependence, but more than three-quarters of persons receiving the treatment report sleep quality disturbances. In this double-blind, randomized, controlled trial, we recruited 90 individuals receiving methadone for at least one month who reported sleep disturbances and had Pittsburgh Sleep Quality Index (PSQI scores > 5. The purpose of this study was to determine whether Suan Zao Ren Tang, one of the most commonly prescribed traditional Chinese medications for treatment of insomnia, improves subjective sleep among methadone-maintained persons with disturbed sleep quality. Ninety patients were randomly assigned to intervention group (n=45 and placebo group (n=45, and all participants were analyzed. Compared with placebo treatment, Suan Zao Ren Tang treatment for four weeks produced a statistically significant improvement in the mean total PSQI scores (P=0.007 and average sleep efficiency (P=0.017. All adverse events (e.g., lethargy, diarrhea, and dizziness were mild in severity. Suan Zao Ren Tang is effective for improving sleep quality and sleep efficiency among methadone-maintained patients with sleep complaints.

  20. Disturbing forest disturbances

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    Volney, W.J.A.; Hirsch, K.G. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada)

    2005-10-01

    This paper described the role that disturbances play in maintaining the ecological integrity of Canadian boreal forests. Potential adaptation options to address the challenges that these disturbances present were also examined. Many forest ecosystems need fire for regeneration, while other forests rely on a cool, wet disintegration process driven by insects and commensal fungi feeding on trees to effect renewal. While there are characteristic natural, temporal and spatial patterns to these disturbances, recent work has demonstrated that the disturbances are being perturbed by climatic change that has been compounded by anthropogenic disturbances in forests. Fire influences species composition and age structure, regulates forest insects and diseases, affects nutrient cycling and energy fluxes, and maintains the productivity of different habitats. Longer fire seasons as a result of climatic change will lead to higher intensity fires that may more easily evade initial attacks and become problematic. Fire regimes elevated beyond the range of natural variation will have a dramatic effect on the regional distribution and functioning of forest ecosystems and pose a threat to the safety and prosperity of people. While it was acknowledged that if insect outbreaks were to be controlled on the entire forest estate, the productivity represented by dead wood would be lost, it was suggested that insects such as the forest tent caterpillar and the spruce bud worm may also pose a greater threat as the climate gets warmer and drier. Together with fungal associates, saproxylic arthropods are active in nutrient cycling and ultimately determine the fertility of forest sites. It was suggested that the production of an age class structure and forest mosaic would render the forest landscape less vulnerable to the more negative aspects of climate change on vegetation response. It was concluded that novel management design paradigms are needed to successfully reduce the risk from threats

  1. Buprenorphine Transdermal System Improves Sleep Quality and Reduces Sleep Disturbance in Patients with Moderate-to-Severe Chronic Low Back Pain: Results from Two Randomized Controlled Trials.

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    Yarlas, Aaron; Miller, Kate; Wen, Warren; Lynch, Shau Yu; Ripa, Steven R; Pergolizzi, Joseph V; Raffa, Robert B

    2016-03-01

    To evaluate the impact of buprenorphine (Butrans®) transdermal System (BTDS) treatment on sleep outcomes for patients with moderate-to-severe chronic low back pain (CLBP). Two enriched-enrollment, randomized-withdrawal, double-blind, controlled trials examined BTDS treatment for patients with moderate-to-severe CLBP. Trial I evaluated BTDS 10 and 20 mcg/hour against a placebo control among opioid-naïve patients. Trial II compared BTDS 20 mcg/hour against a lower-dose control (BTDS 5 mcg/hour) among opioid-experienced patients. The patient-reported Medical Outcomes Study Sleep Scale (MOS-SS) assessed overall sleep quality (Sleep Problems Index [SPI]), Disturbance, and other sleep outcomes. In each trial, MOS-SS scores were compared between target treatment and control arms during the 12-week double-blind phase. Correspondence of changes in sleep outcomes and pain severity and the degree to which pain reduction mediates treatment impact on sleep outcomes were examined. Medical Outcomes Study Sleep Scale scores were collected from 541 (Trial I) and 441 (Trial II) patients prior to randomization and from 369 (Trial I) and 274 (Trial II) patients at week 12. Patients receiving target treatment showed statistically significantly more improvement in SPI and Disturbance scores at 12 weeks than their respective controls (Ps sleep outcomes. Buprenorphine Transdermal System improved sleep quality and disturbance for opioid-naïve and opioid-experienced patients with moderate-to-severe CLBP. Benefits of BTDS for these sleep outcomes emerged within 4 weeks and were maintained over the entire 12-week treatment period. © 2015 Optum. Pain Practice published by Wiley Periodicals, Inc. on behalf of World Institute of Pain.

  2. Evaluation of the efficacy of randomized controlled trials of sensory stimulation interventions for sleeping disturbances in patients with dementia: a systematic review.

    Science.gov (United States)

    Dimitriou, Tatiana-Danai; Tsolaki, Magdalini

    2017-01-01

    The current review aims to evaluate the sensory stimulation interventions in terms of reducing sleeping disturbances in patients with dementia. The nonpharmacological interventions seem to be an efficient, inexpensive, and easy tool for family caregivers. Moreover, sleeping disorders increase caregivers' distress and may lead to hospitalization. A systematic literature search was performed. Eleven randomized controlled trials have been found. Among these eleven trials, one referred to massage therapy and acupuncture, and the other ten studies referred to bright light therapy. The results demonstrated that there are no relevant randomized controlled trials of music therapy, aromatherapy, and multisensory environment/Snoezelen referring to sleeping disturbances. Several studies have been conducted about the effect of the bright light therapy, and there is also another study that combines massage therapy and acupuncture therapy. Sensory stimulation interventions are inexpensive and practical for dementia caregivers; however, only bright light therapy seems to be useful to reduce sleeping problems in dementia. The other sensory stimulation interventions lack evidence, and there is a strong need for further research.

  3. Effect of intermittent aerobic exercise on sleep quality and sleep disturbances in patients with rheumatoid arthritis - design of a randomized controlled trial.

    Science.gov (United States)

    Løppenthin, Katrine; Esbensen, Bente Appel; Jennum, Poul; Østergaard, Mikkel; Christensen, Jesper Frank; Thomsen, Tanja; Bech, Julie Schjerbech; Midtgaard, Julie

    2014-02-21

    Poor sleep is prevalent in patients with systemic inflammatory disorders, including rheumatoid arthritis, and, in addition to fatigue, pain, depression and inflammation, is associated with an increased risk of co-morbidity and all-cause mortality. Whereas non-pharmacological interventions in patients with rheumatoid arthritis have been shown to reduce pain and fatigue, no randomized controlled trials have examined the effect of non-pharmacological interventions on improvement of sleep in patients with rheumatoid arthritis. The aim of this trial was to evaluate the efficacy of an intermittent aerobic exercise intervention on sleep, assessed both objectively and subjectively in patients with rheumatoid arthritis. A randomized controlled trial including 44 patients with rheumatoid arthritis randomly assigned to an exercise training intervention or to a control group. The intervention consists of 18 session intermittent aerobic exercise training on a bicycle ergometer three times a week. Patients are evaluated according to objective changes in sleep as measured by polysomnography (primary outcome). Secondary outcomes include changes in subjective sleep quality and sleep disturbances, fatigue, pain, depressive symptoms, physical function, health-related quality of life and cardiorespiratory fitness. This trial will provide evidence of the effect of intermittent aerobic exercise on the improvement of sleep in patients with rheumatoid arthritis, which is considered important in promotion of health and well-being. As such, the trial meets a currently unmet need for the provision of non-pharmacological treatment initiatives of poor sleep in patients with rheumatoid arthritis. ClinicalTrials.gov Identifier: NCT01966835.

  4. Effect of intermittent aerobic exercise on sleep quality and sleep disturbances in patients with rheumatoid arthritis – design of a randomized controlled trial

    Science.gov (United States)

    2014-01-01

    Background Poor sleep is prevalent in patients with systemic inflammatory disorders, including rheumatoid arthritis, and, in addition to fatigue, pain, depression and inflammation, is associated with an increased risk of co-morbidity and all-cause mortality. Whereas non-pharmacological interventions in patients with rheumatoid arthritis have been shown to reduce pain and fatigue, no randomized controlled trials have examined the effect of non-pharmacological interventions on improvement of sleep in patients with rheumatoid arthritis. The aim of this trial was to evaluate the efficacy of an intermittent aerobic exercise intervention on sleep, assessed both objectively and subjectively in patients with rheumatoid arthritis. Methods/design A randomized controlled trial including 44 patients with rheumatoid arthritis randomly assigned to an exercise training intervention or to a control group. The intervention consists of 18 session intermittent aerobic exercise training on a bicycle ergometer three times a week. Patients are evaluated according to objective changes in sleep as measured by polysomnography (primary outcome). Secondary outcomes include changes in subjective sleep quality and sleep disturbances, fatigue, pain, depressive symptoms, physical function, health-related quality of life and cardiorespiratory fitness. Discussion This trial will provide evidence of the effect of intermittent aerobic exercise on the improvement of sleep in patients with rheumatoid arthritis, which is considered important in promotion of health and well-being. As such, the trial meets a currently unmet need for the provision of non-pharmacological treatment initiatives of poor sleep in patients with rheumatoid arthritis. Trial registration ClinicalTrials.gov Identifier: NCT01966835 PMID:24559487

  5. Randomized expectancy-enhanced placebo-controlled trial of the impact of Quantum BioEnergetic distant healing and paranormal belief on mood disturbance: a pilot study.

    Science.gov (United States)

    Rock, Adam J; Permezel, Fiona E; Storm, Lance

    2012-01-01

    Previous research has demonstrated the effects of ostensible subtle energy on physical systems and subjective experience. However, one subtle energy technique that has been neglected, despite anecdotal support for its efficacy, is Quantum BioEnergetics (QBE). Furthermore, the influence of paranormal belief and experience (either real belief/experience or suggested belief/experience) on subtle energy effects remains unclear. The aim of the present study was to investigate experimentally the effects of distant QBE healing, and paranormal belief/experience, on mood. A randomized expectancy-enhanced placebo-controlled design was used. Data were collected at the QBE Centre, Melbourne. Participants were students from Deakin University and from the general public. Snowball sampling (ie, word-of-mouth) and convenience sampling using a ballot box placed in the university library. Profile of Mood States-Short Form was used to quantify positive and negative mood states. The QBE condition was associated with (1) significantly less Tension-Anxiety compared with the placebo and control condition; and (2) significantly less Anger-Hostility and Total Mood Disturbance compared with the control condition (but not the placebo condition). Furthermore, there was an interaction of condition and paranormal belief/experience with regard to Depression-Dejection, with believers assigned to the placebo condition scoring lowest on this Mood variable. Findings suggest that the use of QBE by an experienced practitioner reduces mood disturbance. In addition, the placebo condition may have evoked suggestibility effects in believers, which would mean that they may be more likely than nonbelievers to believe that they were receiving healing, thus resulting in lower Depression-Dejection scores. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Emotional Disturbance

    Science.gov (United States)

    ... illnesses can affect persons of any age, race, religion, or income. Further: Mental illnesses are not the ... Detailed information on specific emotional disturbances , or related issues such as positive behavior supports, is also available ...

  7. Motor Habits in Visuo-manual Tracking: Manifestation of an Unconscious Short-Term Motor Memory?

    Directory of Open Access Journals (Sweden)

    Andreas Hufschmidt

    1990-01-01

    Full Text Available Normal subjects were tested in short, repetitive trials of a tracking task, with an identical shape of target movement being used throughout one session. Analysis of the net error curves (pursuit minus target movement revealed that subjects regularly exhibit a remoteness effect: neighbouring trials were more similar than distant ones. The effect is demonstrated to be stronger in the absence of visual cues, and was found to be absent in a patient with complete loss of proprioception when he was performing without visual feedback as well. The results are discussed in terms of a short term memory store contributing to unconscious movement habits in tracking. This may represent part of the motor learning process working together with conscious visuo-motor control mechanisms. Its function is probably related to the acquisition of automatic movements.

  8. Video Distraction and Parental Presence for the Management of Preoperative Anxiety and Postoperative Behavioral Disturbance in Children: A Randomized Controlled Trial.

    Science.gov (United States)

    Kim, Hyuckgoo; Jung, Sung Mee; Yu, Hwarim; Park, Sang-Jin

    2015-09-01

    The anxiolytic efficacy of video watching, in the absence of parents, during the mask induction of anesthesia in young children with high separation anxiety has not been clearly established. We performed this study to determine whether the effect of video distraction on alleviating preoperative anxiety is independent of parental presence and whether a combination of both interventions is more effective than either single intervention in alleviating preoperative anxiety and postoperative behavioral disturbance in preschool children. In this prospective trial, 117 children aged 2 to 7 years scheduled for elective minor surgery were randomly allocated to 1 of 3 groups, a video distraction group (group V), a parental presence group (group P), or a combination of video distraction plus parental presence group (group VP) during induction of sevoflurane anesthesia. The Modified Yale Preoperative Anxiety Scale (mYPAS) was used to assess anxiety in the preoperative holding area (baseline), immediately after entry to the operating room, and during mask induction. Compliance during induction, emergence delirium during recovery, and negative behavioral changes at 1 day and 2 weeks postoperatively were also assessed. The mYPAS scores were comparable (P = 0.558), and the number of children exhibiting baseline anxiety (an mYPAS score > 30) were not different among the 3 groups in the preoperative holding area (P = 0.824). After intervention, the changes in mYPAS scores from baseline to induction were not different among the 3 groups (P = 0.049). The proportion of children with increased mYPAS scores was higher in group P compared with group V from baseline to operating room entry (Bonferroni-adjusted 95% confidence interval for difference, 2 to 49) but similar from baseline to induction in all 3 groups. Although children in group V were more cooperative during mask induction than those in the other 2 groups (P anxiety during inhaled induction of anesthesia and postoperative

  9. Prevention of depression and sleep disturbances in elderly with memory-problems by activation of the biological clock with light - a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Scheltens Philip

    2010-02-01

    Full Text Available Abstract Background Depression frequently occurs in the elderly and in patients suffering from dementia. Its cause is largely unknown, but several studies point to a possible contribution of circadian rhythm disturbances. Post-mortem studies on aging, dementia and depression show impaired functioning of the suprachiasmatic nucleus (SCN which is thought to be involved in the increased prevalence of day-night rhythm perturbations in these conditions. Bright light enhances neuronal activity in the SCN. Bright light therapy has beneficial effects on rhythms and mood in institutionalized moderate to advanced demented elderly. In spite of the fact that this is a potentially safe and inexpensive treatment option, no previous clinical trial evaluated the use of long-term daily light therapy to prevent worsening of sleep-wake rhythms and depressive symptoms in early to moderately demented home-dwelling elderly. Methods/Design This study investigates whether long-term daily bright light prevents worsening of sleep-wake rhythms and depressive symptoms in elderly people with memory complaints. Patients with early Alzheimer's Disease (AD, Mild Cognitive Impairment (MCI and Subjective Memory Complaints (SMC, between the ages of 50 and 75, are included in a randomized double-blind placebo-controlled trial. For the duration of two years, patients are exposed to ~10,000 lux in the active condition or ~300 lux in the placebo condition, daily, for two half-hour sessions at fixed times in the morning and evening. Neuropsychological, behavioral, physiological and endocrine measures are assessed at baseline and follow-up every five to six months. Discussion If bright light therapy attenuates the worsening of sleep-wake rhythms and depressive symptoms, it will provide a measure that is easy to implement in the homes of elderly people with memory complaints, to complement treatments with cholinesterase inhibitors, sleep medication or anti-depressants or as a stand

  10. A randomized clinical trial of the effect of intensive versus non-intensive counselling on discontinuation rates due to bleeding disturbances of three long-acting reversible contraceptives.

    Science.gov (United States)

    Modesto, Waleska; Bahamondes, M Valeria; Bahamondes, Luis

    2014-07-01

    Does intensive counselling before insertion and throughout the first year of use have any influence on discontinuation rates due to unpredictable menstrual bleeding in users of three long-acting reversible contraceptives (LARCs)? Intensive counselling had a similar effect to routine counselling in terms of discontinuation rates due to unpredictable menstrual bleeding in new users of the contraceptives. Contraceptive efficacy and satisfaction rates are very high with LARCs, including the etonogestrel (ENG)-releasing implant, the levonorgestrel-releasing intrauterine system (LNG-IUS) and the TCu380A intrauterine device (IUD). However, unpredictable menstrual bleeding constitutes the principal reason for premature discontinuation, particularly in the cases of the ENG-implant and the LNG-IUS. A randomized clinical trial was conducted between 2011 and 2013, and involved 297 women: 98 ENG-implant users, 99 LNG-IUS users and 100 TCu380A IUD users. Women accepting each contraceptive method were randomized into two groups after the women chose their contraceptive method. Group I received routine counselling at the clinic, including information on safety, efficacy and side effects, as well as what to expect regarding bleeding disturbances. Group II received 'intensive counselling'. In addition to the information provided to those in Group I, these women also received leaflets on their chosen method and were seen by the same three professionals, the most experienced at the clinic, throughout the year of follow-up. These three professionals went over all the information provided at each consultation. Women in both groups were instructed to return to the clinic after 45 (±7) days and at 6 and 12 (±1) months after insertion. They were instructed to record all bleeding episodes on a menstrual calendar specifically provided for this purpose. Additionally, satisfaction with the method was evaluated by a questionnaire completed by the women after 12 months of use of the

  11. Prevention of depression and sleep disturbances in elderly with memory-problems by activation of the biological clock with light - a randomized clinical trial

    NARCIS (Netherlands)

    Most, E.I.S.; Scheltens, P.; van Someren, E.J.W.

    2010-01-01

    Background: Depression frequently occurs in the elderly and in patients suffering from dementia. Its cause is largely unknown, but several studies point to a possible contribution of circadian rhythm disturbances. Post-mortem studies on aging, dementia and depression show impaired functioning of the

  12. Combined STN/SNr-DBS for the treatment of refractory gait disturbances in Parkinson's disease: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Fritz Melanie

    2011-10-01

    Full Text Available Abstract Background Severe gait disturbances in idiopathic Parkinson's disease (PD are observed in up to 80% of all patients in advanced disease stages with important impact on quality of life. There is an unmet need for further symptomatic therapeutic strategies, particularly as gait disturbances generally respond unfavourably to dopaminergic medication and conventional deep brain stimulation of the subthalamic nucleus in advanced disease stages. Recent pathophysiological research pointed to nigro-pontine networks entrained to locomotor integration. Stimulation of the pedunculopontine nucleus is currently under investigation, however, hitherto remains controversial. The substantia nigra pars reticulata (SNr - entrained into integrative locomotor networks - is pathologically overactive in PD. High-frequent stimulation of the substantia nigra pars reticulata preferentially modulated axial symptoms and therefore is suggested as a novel therapeutic candidate target for neuromodulation of refractory gait disturbances in PD. Methods 12 patients with idiopathic Parkinson's disease and refractory gait disturbances under best individual subthalamic nucleus stimulation and dopaminergic medication will be enroled into this double-blind 2 × 2 cross-over clinical trial. The treatment consists of two different stimulation settings using (i conventional stimulation of the subthalamic nucleus [STNmono] and (ii combined stimulation of distant electrode contacts located in the subthalamic nucleus and caudal border zone of STN and substantia nigra pars reticulata [STN+SNr]. The primary outcome measure is the change of the cumulative 'axial score' (UPDRS II items '13-15' and UPRDS III items '27-31' at three weeks of constant stimulation in either condition. Secondary outcome measures include specific scores on freezing of gait, balance function, quality of life, non-motor symptoms, and neuropsychiatric symptoms. The aim of the present trial is to investigate the

  13. Effect of a participatory organizational-level occupational health intervention on job satisfaction, exhaustion and sleep disturbances: results of a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Elisabeth Framke

    2016-11-01

    Full Text Available Abstract Background We examined whether the implementation of a participatory organizational-level intervention aiming to improve the working environment with a focus on the core task at work, increased job satisfaction and reduced exhaustion and sleep disturbances among pre-school employees. Methods The study sample consisted of 41 intervention group pre-schools with 423 employees and 30 control group pre-schools with 241 employees. The intervention lasted 25 months and consisted of seminars, workshops, and workplace specific intervention activities that were developed by focusing on the core task at work. We analyzed within-group changes in the three outcome variables from baseline to follow-up with t-tests for paired samples, separately for intervention and control group. Between-group differences in changes in the three outcome variables were analyzed using a mixed model with a repeated statement to account for the clustering effect of workplaces. Results Within-group analyses showed that exhaustion decreased statistically significantly in both the intervention and the control group. There were no statistically significantly changes in job satisfaction and sleep disturbances. Between-group analyses showed that there was no statistically significant difference between the two groups for changes in any of the outcome variables, neither in the unadjusted or in the adjusted analyses. Conclusions We found no evidence that participating in an organizational-level occupational health intervention aiming to improve the working environment with a focus on the core task at work has an effect on pre-school employees’ job satisfaction, exhaustion and sleep disturbances. Trial registration ISRCTN16271504 , November 15, 2016.

  14. The effectiveness of Multidimensional Treatment Foster Care for Preschoolers (MTFC-P) for young children with severe behavioral disturbances: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Jonkman, Caroline S; Schuengel, Carlo; Lindeboom, Robert; Oosterman, Mirjam; Boer, Frits; Lindauer, Ramon J L

    2013-07-05

    Among children placed out of home, behavioral and relationship functioning is often problematic. When placed in foster care, problems tend to persist or even worsen and increase the risk of placement breakdown. Multidimensional Treatment Foster Care for Preschoolers is an intensive behavior-focused program for young foster children (3 to 7 years) aiming to provide children with a positive and stimulating foster family setting and individually tailored behavioral interventions. This study will be the first to examine the effectiveness of Multidimensional Treatment Foster Care for Preschoolers outside the US and to examine the effectiveness across a broader range of problems related to foster care. This is a randomized controlled trial, wherein we expect to include 80 child-foster carer dyads. Forty dyads will be assigned to Multidimensional Treatment Foster Care for Preschoolers and 40 to treatment as usual, following pre-randomization. Data to be gathered concern problem behavior, symptoms of attachment disorder, post-traumatic stress symptoms, quality of life, hypothalamic-adrenal-pituitary axis functioning, parental stress and autonomic reactivity, to be collected via questionnaires, observations, interviews, saliva and recording at six time-points over 24 months. To compare treatment outcomes, Fisher's exact tests and repeated measures (mixed models) and independent t-tests will be used. All analyses will be performed following the intention-to-treat principle. Examining the generalizability of previous findings in the US and extending these previous findings is a step towards improving knowledge about treatment of young foster children with severe behavioral, emotional and attachment problems. NTR1747.

  15. Effects of an intervention with drinking chamomile tea on sleep quality and depression in sleep disturbed postnatal women: a randomized controlled trial.

    Science.gov (United States)

    Chang, Shao-Min; Chen, Chung-Hey

    2016-02-01

    The purpose of this study was to evaluate the effects of chamomile tea on sleep quality, fatigue and depression in postpartum women. Sleep quality is a significant issue for postnatal women. Chamomile is widely used as a folk remedy for its presumed sedative-hypnotic effects. A pretest-post-test randomized controlled trial was used. A total of 80 Taiwanese postnatal women with poor sleep quality (Postpartum Sleep Quality Scale; PSQS score ≧16) were recruited from November 2012-August 2013. They were systematically assigned, with a random start, to either the experimental group (n = 40) or the control group (n = 40). The participants in the experimental group were instructed to drink chamomile tea for a period of 2 weeks. The participants in the control group received regular postpartum care only. The PSQS, Edinburgh Postnatal Depression Scale, and Postpartum Fatigue Scale were used to assess outcomes. Two-sample t-tests were used to examine the mean differences in outcome variables between the two groups. Compared with the control group, the experimental group demonstrated significantly lower scores of physical-symptoms-related sleep inefficiency (t = -2·482, P = 0·015) and the symptoms of depression (t = -2·372, P = 0·020). However, the scores for all three instruments were similar for both groups at 4-week post-test, suggesting that the positive effects of chamomile tea were limited to the immediate term. Chamomile tea may be recommended to postpartum women as a supplementary approach to alleviating depression and sleep quality problems. © 2015 John Wiley & Sons Ltd.

  16. No double-dissociation between optic ataxia and visual agnosia: Multiple sub-streams for multiple visuo-manual integrations

    NARCIS (Netherlands)

    Pisella, L.; Binkofski, F.; Lasek, K.; Toni, I.; Rossetti, Y.

    2006-01-01

    The current dominant view of the visual system is marked by the functional and anatomical dissociation between a ventral stream specialised for perception and a dorsal stream specialised for action. The "double-dissociation" between visual agnosia (VA), a deficit of visual recognition, and optic

  17. Treating disturbances in the relationship between mothers with bulimic eating disorders and their infants: a randomized, controlled trial of video feedback.

    Science.gov (United States)

    Stein, Alan; Woolley, Helen; Senior, Robert; Hertzmann, Leezah; Lovel, Mary; Lee, Joanna; Cooper, Sandra; Wheatcroft, Rebecca; Challacombe, Fiona; Patel, Priti; Nicol-Harper, Rosemary; Menzes, Pia; Schmidt, Anne; Juszczak, Edmund; Fairburn, Christopher G

    2006-05-01

    Maternal eating disorders interfere with parenting, adversely affecting mother-infant interaction and infant outcome. This trial tested whether video-feedback treatment specifically targeting mother-child interaction would be superior to counseling in improving mother-child interaction, especially mealtime conflict, and infant weight and autonomy. The participants were 80 mothers with bulimia nervosa or similar eating disorder who were attending routine baby clinics and whose infants were 4-6 months old. They were randomly assigned to video-feedback interactional treatment or supportive counseling. Both groups also received guided cognitive behavior self-help for their eating disorder. Each group received 13 sessions. The primary outcome measure was mealtime conflict; secondary outcome measures were infant weight, aspects of mother-infant interaction, and infant autonomy. Seventy-seven mothers were followed up when their infants were 13 months old. The video-feedback group exhibited significantly less mealtime conflict than the control subjects. Nine of 38 (23.7%) in the video-feedback group showed episodes of marked or severe conflict, compared with 21 of 39 (53.8%) control subjects (odds ratio=0.27, 95% confidence interval=0.10 to 0.73). Video feedback produced significant improvements in several other interaction measures and greater infant autonomy. Both groups maintained good infant weight, with no differences between groups. Maternal eating psychopathology was reduced across both groups. Video-feedback treatment focusing on mother-infant interaction produced improvements in interaction and infant autonomy, and both groups maintained adequate infant weight. To the authors' knowledge, this is the first controlled trial to show key improvements in interaction between mothers with postnatal psychiatric disorders and their infants.

  18. Entropic error-disturbance relations

    Science.gov (United States)

    Coles, Patrick; Furrer, Fabian

    2014-03-01

    We derive an entropic error-disturbance relation for a sequential measurement scenario as originally considered by Heisenberg, and we discuss how our relation could be tested using existing experimental setups. Our relation is valid for discrete observables, such as spin, as well as continuous observables, such as position and momentum. The novel aspect of our relation compared to earlier versions is its clear operational interpretation and the quantification of error and disturbance using entropic quantities. This directly relates the measurement uncertainty, a fundamental property of quantum mechanics, to information theoretical limitations and offers potential applications in for instance quantum cryptography. PC is funded by National Research Foundation Singapore and Ministry of Education Tier 3 Grant ``Random numbers from quantum processes'' (MOE2012-T3-1-009). FF is funded by Japan Society for the Promotion of Science, KAKENHI grant No. 24-02793.

  19. Sudden Ionospheric Disturbances (SID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden ionospheric disturbances (SID) are caused by solar flare enhanced X-rays in the 1 to 10 angstrom range. Solar flares can produce large increases of ionization...

  20. Forest development leading to disturbances

    Science.gov (United States)

    Clinton E. Carlson; Stephen F. Arno; Jimmie Chew; Catherine A. Stewart

    1995-01-01

    Natural disturbance in western U.S.A. forest ecosystems is related to forest succession, growth, and structural development. Natural disturbance may be biotic (insects and diseases) or abiotic (fire, wind, avalanche, etc.). Natural disturbances are more appropriately thought of as natural processes; disturbance is a social connotation implicating economic loss. Forest...

  1. Nutritional disturbances by adolescent

    OpenAIRE

    Stassart, Martine

    2011-01-01

    The nutritional disturbances are frequent by adolescents. That is a psychological defense against dependance toward the mother but also a middle to remain in a childish position i.e. either as a fat baby - in the fall of obesity- or as the ideal pre- or bisexual great child - in the case of anorexia.

  2. Forest disturbances under climate change

    Science.gov (United States)

    Seidl, Rupert; Thom, Dominik; Kautz, Markus; Martin-Benito, Dario; Peltoniemi, Mikko; Vacchiano, Giorgio; Wild, Jan; Ascoli, Davide; Petr, Michal; Honkaniemi, Juha; Lexer, Manfred J.; Trotsiuk, Volodymyr; Mairota, Paola; Svoboda, Miroslav; Fabrika, Marek; Nagel, Thomas A.; Reyer, Christopher P. O.

    2017-06-01

    Forest disturbances are sensitive to climate. However, our understanding of disturbance dynamics in response to climatic changes remains incomplete, particularly regarding large-scale patterns, interaction effects and dampening feedbacks. Here we provide a global synthesis of climate change effects on important abiotic (fire, drought, wind, snow and ice) and biotic (insects and pathogens) disturbance agents. Warmer and drier conditions particularly facilitate fire, drought and insect disturbances, while warmer and wetter conditions increase disturbances from wind and pathogens. Widespread interactions between agents are likely to amplify disturbances, while indirect climate effects such as vegetation changes can dampen long-term disturbance sensitivities to climate. Future changes in disturbance are likely to be most pronounced in coniferous forests and the boreal biome. We conclude that both ecosystems and society should be prepared for an increasingly disturbed future of forests.

  3. Forest disturbances under climate change

    Science.gov (United States)

    Seidl, Rupert; Thom, Dominik; Kautz, Markus; Martin-Benito, Dario; Peltoniemi, Mikko; Vacchiano, Giorgio; Wild, Jan; Ascoli, Davide; Petr, Michal; Honkaniemi, Juha; Lexer, Manfred J.; Trotsiuk, Volodymyr; Mairota, Paola; Svoboda, Miroslav; Fabrika, Marek; Nagel, Thomas A.; Reyer, Christopher P. O.

    2017-01-01

    Forest disturbances are sensitive to climate. However, our understanding of disturbance dynamics in response to climatic changes remains incomplete, particularly regarding large-scale patterns, interaction effects and dampening feedbacks. Here we provide a global synthesis of climate change effects on important abiotic (fire, drought, wind, snow and ice) and biotic (insects and pathogens) disturbance agents. Warmer and drier conditions particularly facilitate fire, drought and insect disturbances, while warmer and wetter conditions increase disturbances from wind and pathogens. Widespread interactions between agents are likely to amplify disturbances, while indirect climate effects such as vegetation changes can dampen long-term disturbance sensitivities to climate. Future changes in disturbance are likely to be most pronounced in coniferous forests and the boreal biome. We conclude that both ecosystems and society should be prepared for an increasingly disturbed future of forests. PMID:28861124

  4. 300 Area Disturbance Report

    Energy Technology Data Exchange (ETDEWEB)

    LL Hale; MK Wright; NA Cadoret

    1999-01-07

    The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic

  5. Postoperative circadian disturbances

    DEFF Research Database (Denmark)

    Gögenur, Ismail

    2010-01-01

    in patients with lower than median pain levels for a three days period after laparoscopic cholecystectomy. In the series of studies included in this thesis we have systematically shown that circadian disturbances are found in the secretion of hormones, the sleep-wake cycle, core body temperature rhythm......An increasing number of studies have shown that circadian variation in the excretion of hormones, the sleep wake circle, the core body temperature rhythm, the tone of the autonomic nervous system and the activity rhythm are important both in health and in disease processes. An increasing attention...... night after minimally invasive surgery. The core body temperature rhythm was disturbed after both major and minor surgery. There was a change in the sleep wake cycle with a significantly increased duration of REM-sleep in the day and evening time after major surgery compared with preoperatively...

  6. Postoperative circadian disturbances

    DEFF Research Database (Denmark)

    Gögenur, Ismail

    2010-01-01

    night after minimally invasive surgery. The core body temperature rhythm was disturbed after both major and minor surgery. There was a change in the sleep wake cycle with a significantly increased duration of REM-sleep in the day and evening time after major surgery compared with preoperatively....... There was also a shift in the autonomic nervous balance after major surgery with a significantly increased number of myocardial ischaemic episodes during the nighttime period. The circadian activity rhythm was also disturbed after both minor and major surgery. The daytime AMT6s excretion in urine after major...... surgery was increased on the fourth day after surgery and the total excretion of AMT6s in urine was correlated to sleep efficiency and wake time after sleep onset, but was not correlated to the occurrence of postoperative cognitive dysfunction. We could only prove an effect of melatonin substitution...

  7. Identity disturbance in adolescence: associations with borderline personality disorder.

    Science.gov (United States)

    Westen, Drew; Betan, Ephi; Defife, Jared A

    2011-02-01

    Although establishing a coherent identity is often viewed as a normative developmental task of adolescence, an important question is whether forms of identity disturbance seen in adult personality disorders can also be distinguished in adolescents. If so, such disturbances would constitute an essential target for research and clinical interventions. The goal of this study is to investigate the nature of identity disturbance in an adolescent clinical sample and to explore its links with personality pathology, particularly borderline personality disorder. A national random sample of 139 psychiatrists and clinical psychologists completed a battery of instruments on a randomly selected adolescent patient in their care, including measures of Axis II symptoms and the Identity Disturbance Questionnaire-Adolescent Version, an instrument designed for clinically experienced observers that assesses a wide range of manifestations of potential identity disturbance among adolescents. Factor analysis of the Identity Disturbance Questionnaire--Adolescent Version yielded four clinically and conceptually coherent factors that resembled dimensions previously identified in adults: lack of normative commitment, role absorption, painful incoherence, and lack of consistency. As in adults, identity disturbance in adolescents is a clinically meaningful, multidimensional construct exhibiting significant relationships with different forms of severe personality pathology, most notably borderline personality disorder. As such, identity disturbance can be a manifestation of psychopathology above and beyond the typical Sturm und Drang (storm and stress) of adolescence.

  8. Sleep Disturbances in Depression.

    Science.gov (United States)

    Murphy, Michael J; Peterson, Michael J

    2015-03-01

    Major depressive disorder is frequently accompanied by sleep disturbances such as insomnia or hypersomnia and polysomnographic sleep findings of increased rapid-eye-movement sleep and decreased slow wave sleep. For many patients, insomnia persists even after mood symptoms have been adequately treated. These patients have poorer outcomes than patients without sleep problems. These outcomes suggest that overlapping neural mechanisms regulate sleep and mood. Treatment of these patients can incorporate sedating antidepressants, nonbenzodiazepine γ-aminobutyric acid agonists, and cognitive behavioral therapy. Sleep restriction has been found to improve mood in depressed patients; however, the benefits typically disappear after recovery sleep. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Defining Disturbance for Microbial Ecology.

    Science.gov (United States)

    Plante, Craig J

    2017-08-01

    Disturbance can profoundly modify the structure of natural communities. However, microbial ecologists' concept of "disturbance" has often deviated from conventional practice. Definitions (or implicit usage) have frequently included climate change and other forms of chronic environmental stress, which contradict the macrobiologist's notion of disturbance as a discrete event that removes biomass. Physical constraints and disparate biological characteristics were compared to ask whether disturbances fundamentally differ in microbial and macroorganismal communities. A definition of "disturbance" for microbial ecologists is proposed that distinguishes from "stress" and other competing terms, and that is in accord with definitions accepted by plant and animal ecologists.

  10. Postoperative circadian disturbances.

    Science.gov (United States)

    Gögenur, Ismail

    2010-12-01

    An increasing number of studies have shown that circadian variation in the excretion of hormones, the sleep wake circle, the core body temperature rhythm, the tone of the autonomic nervous system and the activity rhythm are important both in health and in disease processes. An increasing attention has also been directed towards the circadian variation in endogenous rhythms in relation to surgery. The attention has been directed to the question whether the circadian variation in endogenous rhythms can affect postoperative recovery, morbidity and mortality. Based on the lack of studies where these endogenous rhythms have been investigated in relation to surgery we performed a series of studies exploring different endogenous rhythms and factors affecting these rhythms. We also wanted to examine whether the disturbances in the postoperative circadian rhythms could be correlated to postoperative recovery parameters, and if pharmacological administration of chronobiotics could improve postoperative recovery. Circadian rhythm disturbances were found in all the examined endogenous rhythms. A delay was found in the endogenous rhythm of plasma melatonin and excretion of the metabolite of melatonin (AMT6s) in urine the first night after both minor and major surgery. This delay after major surgery was correlated to the duration of surgery. The amplitude in the melatonin rhythm was unchanged the first night but increased in the second night after major surgery. The amplitude in AMT6s was reduced the first night after minimally invasive surgery. The core body temperature rhythm was disturbed after both major and minor surgery. There was a change in the sleep wake cycle with a significantly increased duration of REM-sleep in the day and evening time after major surgery compared with preoperatively. There was also a shift in the autonomic nervous balance after major surgery with a significantly increased number of myocardial ischaemic episodes during the nighttime period. The

  11. Disturbance hydrology: Preparing for an increasingly disturbed future

    Science.gov (United States)

    Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

    2017-01-01

    This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre- and post-disturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

  12. Postischaemic circulation disturbances.

    Science.gov (United States)

    Fuchs, U; Bodendieck, P

    1975-01-01

    Restoration of blood supply after ischaemic conditions in extremities and testes is inhibited by reversible intravasal aggregation of erythrocytes. This process is promoted by the increased permeability of the capillaries associated with the formation of oedema and the entailing increase of the haematocrit. For overcoming the stasis the increased structural viscosity caused by the aggregation of erythrocytes requires an increase in pressure as a starter effect which is not achieved by the flow pressure at once everywhere. Intravenously administered particles of Indian ink mark the formation and dissolution of aggregates. Even areas with originally normal blood supply may be obstructed by the later formation of aggregates. Thrombi on the walls of arterial and venous vessels and other lesions of the intima do not sufficiently explain the disturbance of perfusion. Oedema and extravasating leucocytes are found in the microcirculation. The parenchyma to be supplied shows formation of necrosis.

  13. Sleep Disturbances in Mood Disorders.

    Science.gov (United States)

    Rumble, Meredith E; White, Kaitlin Hanley; Benca, Ruth M

    2015-12-01

    The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Sleep disturbances and PTSD: a perpetual circle?

    Directory of Open Access Journals (Sweden)

    Saskia van Liempt

    2012-10-01

    Full Text Available Background : Sleep facilitates the consolidation of fear extinction memory. Nightmares and insomnia are hallmark symptoms of posttraumatic stress disorder (PTSD, possibly interfering with fear extinction and compromising recovery. A perpetual circle may develop when sleep disturbances increase the risk for PTSD and vice versa. To date, therapeutic options for alleviating sleep disturbances in PTSD are limited. Methods : We conducted three studies to examine the relationship between sleep and posttraumatic symptoms: (1 a prospective longitudinal cohort study examining the impact of pre-deployment insomnia symptoms and nightmares on the development of PTSD; (2 a cross-sectional study examining subjective sleep measures, polysomnography, endocrinological parameters, and memory in veterans with PTSD, veterans without PTSD, and healthy controls (HCs; (3 a randomized controlled trial (RCT (n=14 comparing the effect of prazosin and placebo on sleep disturbances in veterans with PTSD. In addition to these studies, we systematically reviewed the literature on treatment options for sleep disturbances in PTSD. Results : Pre-deployment nightmares predicted PTSD symptoms at 6 months post-deployment; however, insomnia symptoms did not. Furthermore, in patients with PTSD, a correlation between the apnea index and PTSD severity was observed, while obstructive sleep apnea syndrome was not more prevalent. We observed a significant increase in awakenings during sleep in patients with PTSD, which were positively correlated with adrenocorticotropic hormone (ACTH levels, negatively correlated with growth hormone (GH secretion, and the subjective perception of sleep depth. Also, heart rate was significantly increased in PTSD patients. Interestingly, plasma levels of GH during the night were decreased in PTSD. Furthermore, GH secretion and awakenings were independent predictors for delayed recall, which was lower in PTSD. In our RCT, prazosin was not associated with

  15. The simulation of occasional road disturbances for studying mobile vehicles dynamics

    Directory of Open Access Journals (Sweden)

    T.A. Alexeeva

    2015-06-01

    Full Text Available This paper presents a procedure for simulating random road disturbances based on the method of non-canonically decomposing random functions in the form of deterministic functions depending on just three random quantities under any probability distribution law. The mathematical methods developed for modeling random road disturbances give an accurate representation of the random function perturbations in the framework of the correlation theory using just three random variables. The proposed approach allows to obtain more reliable data on the spectral composition of the microrelief, to simplify the study of the dynamics of mobile vehicles and reduce the amount of computation in comparison with other methods.

  16. Sleep disturbances and glucose homeostasis

    NARCIS (Netherlands)

    Barf, R. Paulien; Scheurink, Anton J.W.

    2011-01-01

    Sleep disturbances, induced by either lifestyle, shift work or sleeping disorders, have become more prevalent in our 24/7 Western society. Sleep disturbances are associated with impaired health including metabolic diseases such as obesity and type 2 diabetes. The question remains whether there is a

  17. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    Science.gov (United States)

    Blaurock, Carl

    2009-01-01

    The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

  18. Probabilistic risk models for multiple disturbances: an example of forest insects and wildfires

    Science.gov (United States)

    Haiganoush K. Preisler; Alan A. Ager; Jane L. Hayes

    2010-01-01

    Building probabilistic risk models for highly random forest disturbances like wildfire and forest insect outbreaks is a challenging. Modeling the interactions among natural disturbances is even more difficult. In the case of wildfire and forest insects, we looked at the probability of a large fire given an insect outbreak and also the incidence of insect outbreaks...

  19. Structural Disturbances in Rural Communities: Some Repercussions of the Migration Turnaround in Michigan.

    Science.gov (United States)

    Clay, Daniel C.; Price, Michael L.

    The recent, widespread trend toward rural migration can create disturbances in the organization of the host community by overloading community services and by creating conflict between oldtimers and newcomers. To obtain information about community disturbances and migration in Michigan, questionnaires were sent to a random sample of 21,792…

  20. Managing Sleep Disturbances in Cirrhosis

    Directory of Open Access Journals (Sweden)

    Xun Zhao

    2016-01-01

    Full Text Available Sleep disturbances, particularly daytime sleepiness and insomnia, are common problems reported by patients suffering from liver cirrhosis. Poor sleep negatively impacts patients’ quality of life and cognitive functions and increases mortality. Although sleep disturbances can be an early sign of hepatic encephalopathy (HE, many patients without HE still complain of poor quality sleep. The pathophysiology of these disturbances is not fully understood but is believed to be linked to impaired hepatic melatonin metabolism. This paper provides an overview for the clinician of common comorbidities contributing to poor sleep in patients with liver disease, mainly restless leg syndrome and obstructive sleep apnea. It discusses nondrug and pharmacologic treatment options in these patients, such as the use of light therapy and histamine (H1 blockers.

  1. State Definitions of Emotional Disturbance

    Science.gov (United States)

    Wery, Jessica J.; Cullinan, Douglas

    2013-01-01

    This article examines definitions state education agencies use to describe the federal education disability called "emotional disturbance." State definitions were collected so that various aspects of them could be analyzed and compared with results of similar studies completed in the 1970s and 1980s. Among results are that state definitions have…

  2. Adaptive stochastic disturbance accommodating control

    Science.gov (United States)

    George, Jemin; Singla, Puneet; Crassidis, John L.

    2011-02-01

    This article presents a Kalman filter based adaptive disturbance accommodating stochastic control scheme for linear uncertain systems to minimise the adverse effects of both model uncertainties and external disturbances. Instead of dealing with system uncertainties and external disturbances separately, the disturbance accommodating control scheme lumps the overall effects of these errors in a to-be-determined model-error vector and then utilises a Kalman filter in the feedback loop for simultaneously estimating the system states and the model-error vector from noisy measurements. Since the model-error dynamics is unknown, the process noise covariance associated with the model-error dynamics is used to empirically tune the Kalman filter to yield accurate estimates. A rigorous stochastic stability analysis reveals a lower bound requirement on the assumed system process noise covariance to ensure the stability of the controlled system when the nominal control action on the true plant is unstable. An adaptive law is synthesised for the selection of stabilising system process noise covariance. Simulation results are presented where the proposed control scheme is implemented on a two degree-of-freedom helicopter.

  3. Sleep Disturbances in Frontotemporal Dementia.

    Science.gov (United States)

    McCarter, Stuart J; St Louis, Erik K; Boeve, Bradley F

    2016-09-01

    Sleep disorders appear to be frequent comorbidities in patients with frontotemporal dementia (FTD). Insomnia and excessive daytime sleepiness commonly occur in patients with FTD and significantly contribute to caregiver burden and burnout. Sleep is severely fragmented in FTD patients, likely secondary to behavioral disturbances, other primary sleep disorders such as sleep disordered breathing and restless leg syndrome, and neurodegeneration of nuclei involved in sleep and wakefulness. Treatment of primary sleep disorders may improve excessive daytime sleepiness and sleep quality and may improve daytime cognitive functioning. Rapid eye movement (REM) sleep behavior disorder is rare in FTD and may be confused with excessive nocturnal activity due to disturbed circadian rhythm. The relationship between FTD, sleep quality, and sleep disorders requires further study to better understand the contribution of disturbed sleep to daytime neurocognitive functioning and quality of life in FTD. Further, future studies should focus on comparing sleep disturbances between different FTD syndromes, especially behavioral variant FTD and primary progressive aphasia. Comorbid sleep disorders should be promptly sought and treated in patients with FTD to improve patient and caregiver quality of life.

  4. Immediate response of meio and macrobenthos to disturbance caused by a benthic disturber

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Ansari, Z.A.; Matondkar, S.G.P.; Rodrigues, N.

    of meiobenthos and macrobenthos. These studies were repeated on sediment samples colleced from the same stations of Indian Basin immediately after the disturbance on a 3000m x 200m disturbance track and outside the disturbance track. Characteristic changes...

  5. Extended Active Disturbance Rejection Controller

    Science.gov (United States)

    Gao, Zhiqiang (Inventor); Tian, Gang (Inventor)

    2016-01-01

    Multiple designs, systems, methods and processes for controlling a system or plant using an extended active disturbance rejection control (ADRC) based controller are presented. The extended ADRC controller accepts sensor information from the plant. The sensor information is used in conjunction with an extended state observer in combination with a predictor that estimates and predicts the current state of the plant and a co-joined estimate of the system disturbances and system dynamics. The extended state observer estimates and predictions are used in conjunction with a control law that generates an input to the system based in part on the extended state observer estimates and predictions as well as a desired trajectory for the plant to follow.

  6. Micturitional disturbance in Wernicke's encephalopathy.

    Science.gov (United States)

    Sakakibara, R; Hattori, T; Yasuda, K; Yamanishi, T; Tojo, M; Mori, M

    1997-01-01

    A 24-year-old pregnant woman started to have hyperemesis gravidarum 6 weeks before admission. Four weeks later she had vertigo, diplopia, staggering gait, mild dyspnea, dysphagia, and incontinence of urine. On admission she presented with ophthalmoplegia, ptosis, ataxia, decreased tendon reflex, and memory disturbance. Brain magnetic resonance imaging revealed abnormal intensities in medial thalamic-hypothalamic regions and the periaqueductal area, and she was diagnosed with Wernicke's encephalopathy. Urodynamic studies revealed decreased bladder volume and detrusor hyperreflexia. Six weeks after the administration of 100 mg/day of thiamine, urge incontinence gradually recovered, together with neurological signs. Lesions of the medial thalamic-hypothalamic area and the periaqueductal gray matter seemed to be mainly responsible for micturitional disturbance in our patient with Wernicke's encephalopathy.

  7. Disturbances in small bowel motility.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    Recently, the small intestine has become the focus of investigation as a potential site of dysmotility in the irritable bowel syndrome (IBS). A number of motor abnormalities have been defined in some studies, and include \\'clustered\\' contractions, exaggerated post-prandial motor response and disturbances in intestinal transit. The significance of these findings remains unclear. The interpretation of available studies is complicated by differences in subject selection, the direct influence of certain symptoms, such as diarrhoea and constipation, and the interference of compounding factors, such as stress and psychopathology. Dysmotility could also reflect autonomic dysfunction, disturbed CNS control and the response to heightened visceral sensation or central perception. While motor abnormalities may not explain all symptoms in IBS, sensorimotor interactions may be important in symptom pathogenesis and deserve further study.

  8. Natural disturbances and Kyoto protocol

    Directory of Open Access Journals (Sweden)

    Teobaldelli M

    2008-06-01

    Full Text Available A recent letter published in Nature (Kurz et al. 2008a reports an outbreak of mountain pine beetles in British Columbia, destroying millions of trees; according to the authors, by 2020, the beetles will have done so much damage that the forest is expected to release more carbon dioxide than it absorbs. All those natural disturbances could overwhelmed all the efforts made by Canada to influence the carbon balance through forest management. Considering that Canada decided not to elect forest management within the Kyoto Protocol, it is clear that future climate mitigation agreements, aimed to encourage changes in forest management, should account for and protect against the impacts of natural disturbances.

  9. Visual Disturbances: Related to Migraine or Not?

    Science.gov (United States)

    ... Spotlight On News Content Capsule Contact Understanding Migraine Visual Disturbances: Related to Migraine or Not? Doctor Q& ... of Headache Disorders Cluster Headache Post-Traumatic Headache Visual Disturbances: Related to Migraine or Not? February 5, ...

  10. MAPPING DISTURBANCE DYNAMICS IN WET SCLEROPHYLL FORESTS USING TIME SERIES LANDSAT

    Directory of Open Access Journals (Sweden)

    A. Haywood

    2016-06-01

    Full Text Available In this study, we characterised the temporal-spectral patterns associated with identifying acute-severity disturbances and low-severity disturbances between 1985 and 2011 with the objective to test whether different disturbance agents within these categories can be identified with annual Landsat time series data. We analysed a representative State forest within the Central Highlands which has been exposed to a range of disturbances over the last 30 years, including timber harvesting (clearfell, selective and thinning and fire (wildfire and prescribed burning. We fitted spectral time series models to annual normal burn ratio (NBR and Tasseled Cap Indices (TCI, from which we extracted a range of disturbance and recovery metrics. With these metrics, three hierarchical random forest models were trained to 1 distinguish acute-severity disturbances from low-severity disturbances; 2a attribute the disturbance agents most likely within the acute-severity class; 2b and attribute the disturbance agents most likely within the low-severity class. Disturbance types (acute severity and low-severity were successfully mapped with an overall accuracy of 72.9 %, and the individual disturbance types were successfully attributed with overall accuracies ranging from 53.2 % to 64.3 %. Low-severity disturbance agents were successfully mapped with an overall accuracy of 80.2 %, and individual agents were successfully attributed with overall accuracies ranging from 25.5 % to 95.1. Acute-severity disturbance agents were successfully mapped with an overall accuracy of 95.4 %, and individual agents were successfully attributed with overall accuracies ranging from 94.2 % to 95.2 %. Spectral metrics describing the disturbance magnitude were more important for distinguishing the disturbance agents than the post-disturbance response slope. Spectral changes associated with planned burning disturbances had generally lower magnitudes than selective harvesting

  11. Model of traveling ionospheric disturbances

    Directory of Open Access Journals (Sweden)

    Fedorenko Yury P.

    2013-10-01

    Full Text Available A multiscale semi-empirical model of traveling ionospheric disturbances (TIDs is developed. The model is based on the following assumptions: (1 TIDs are generated by acoustic-gravity waves (AGWs and propagate as pressure waves; (2 time intervals between adjacent extrema of atmospheric pressure oscillations in a disturbance source are constant; (3 the pressure extrema propagate from the source up to ~14 000 km at a constant horizontal velocity; (4 the velocity of each extremum is determined only by its number in a TID train. The model was validated using literature data on disturbances generated by about 20 surface and high-altitude nuclear explosions, two volcano explosions, one earthquake and by energetic proton precipitation events in the magnetospheric cusp of the northern hemisphere. Model tests using literature data show that the spatial and temporal TID periods may be predicted with an accuracy of 12%. Adequacy of the model was also confirmed by our observations collected using transionospheric sounding. The following TID parameters: amplitudes, horizontal spatial periods, and a TID front inclination angle in a vertical plane are increasing as the distance between an AGW and the excitation source is increasing. Diurnal and seasonal variability of the TID occurrence, defined as ratio of TID events to the total number of observations for the corresponding period, is not observed. However, the TID occurrence was growing from ~50% in 1987 to ~98% in 2010. The results of other studies asserting that the TID occurrence does not depend on the number of sunspots and magnetic activity are confirmed. The TID occurrence has doubled over the period from 1987 to 2010 indicating increasing solar activity which is not associated with sunspot numbers. The dynamics of spatial horizontal periods was studied in a range of 150–35 000 km.

  12. Forest Disturbance Mapping Using Dense Synthetic Landsat/MODIS Time-Series and Permutation-Based Disturbance Index Detection

    Directory of Open Access Journals (Sweden)

    David Frantz

    2016-03-01

    Full Text Available Spatio-temporal information on process-based forest loss is essential for a wide range of applications. Despite remote sensing being the only feasible means of monitoring forest change at regional or greater scales, there is no retrospectively available remote sensor that meets the demand of monitoring forests with the required spatial detail and guaranteed high temporal frequency. As an alternative, we employed the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM to produce a dense synthetic time series by fusing Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS nadir Bidirectional Reflectance Distribution Function (BRDF adjusted reflectance. Forest loss was detected by applying a multi-temporal disturbance detection approach implementing a Disturbance Index-based detection strategy. The detection thresholds were permutated with random numbers for the normal distribution in order to generate a multi-dimensional threshold confidence area. As a result, a more robust parameterization and a spatially more coherent detection could be achieved. (i The original Landsat time series; (ii synthetic time series; and a (iii combined hybrid approach were used to identify the timing and extent of disturbances. The identified clearings in the Landsat detection were verified using an annual woodland clearing dataset from Queensland’s Statewide Landcover and Trees Study. Disturbances caused by stand-replacing events were successfully identified. The increased temporal resolution of the synthetic time series indicated promising additional information on disturbance timing. The results of the hybrid detection unified the benefits of both approaches, i.e., the spatial quality and general accuracy of the Landsat detection and the increased temporal information of synthetic time series. Results indicated that a temporal improvement in the detection of the disturbance date could be achieved relative to the irregularly spaced Landsat

  13. Gait Disturbances in Dystrophic Hamsters

    Directory of Open Access Journals (Sweden)

    Thomas G. Hampton

    2011-01-01

    Full Text Available The delta-sarcoglycan-deficient hamster is an excellent model to study muscular dystrophy. Gait disturbances, important clinically, have not been described in this animal model. We applied ventral plane videography (DigiGait to analyze gait in BIO TO-2 dystrophic and BIO F1B control hamsters walking on a transparent treadmill belt. Stride length was ~13% shorter (<.05 in TO-2 hamsters at 9 months of age compared to F1B hamsters. Hindlimb propulsion duration, an indicator of muscle strength, was shorter in 9-month-old TO-2 (247±8 ms compared to F1B hamsters (272±11 ms; <.05. Braking duration, reflecting generation of ground reaction forces, was delayed in 9-month-old TO-2 (147±6 ms compared to F1B hamsters (126±8 ms; <.05. Hindpaw eversion, evidence of muscle weakness, was greater in 9-month-old TO-2 than in F1B hamsters (17.7±1.2∘ versus 8.7±1.6∘; <.05. Incline and decline walking aggravated gait disturbances in TO-2 hamsters at 3 months of age. Several gait deficits were apparent in TO-2 hamsters at 1 month of age. Quantitative gait analysis demonstrates that dystrophic TO-2 hamsters recapitulate functional aspects of human muscular dystrophy. Early detection of gait abnormalities in a convenient animal model may accelerate the development of therapies for muscular dystrophy.

  14. Eye tracking disturbances in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Sharma Pradeep

    2000-01-01

    Full Text Available Purpose: To study the frequency of different types of eye tracking disturbances in schizophrenia. Materials and Methods: Smooth pursuit eye movements were studied by electro-oculography (EOG in 22 schizophrenic patients (ICD-10 criteria and 15 age and sex-matched controls. The studied parameters included average pursuit gain, number of saccades, the frequency of different types of saccades (catch-up, back-up, anticipatory saccades, and disturbances during fixation. The results were analysed statistically. Results: The average pursuit gain was significantly affected in patients for target velocity of 30°/sec (p=0.007. The catch-up and back-up saccades were more common in cases than controls but the difference was not significant (p=0.39 and 0.36 respectively. The anticipatory saccades were significantly more frequent in cases than controls (p<0.0001 for both 15°/sec and 30°/sec target velocities. This was also correlated with the duration of illness. Conclusion: Anticipatory saccades are significantly more frequent during eye tracking in schizophrenia and appear to be an objective marker for the disease.

  15. Introduction to Random Signals and Noise

    NARCIS (Netherlands)

    van Etten, Wim

    Random signals and noise are present in many engineering systems and networks. Signal processing techniques allow engineers to distinguish between useful signals in audio, video or communication equipment, and interference, which disturbs the desired signal. With a strong mathematical grounding,

  16. Disturbance maintains alternative biome states.

    Science.gov (United States)

    Dantas, Vinícius de L; Hirota, Marina; Oliveira, Rafael S; Pausas, Juli G

    2016-01-01

    Understanding the mechanisms controlling the distribution of biomes remains a challenge. Although tropical biome distribution has traditionally been explained by climate and soil, contrasting vegetation types often occur as mosaics with sharp boundaries under very similar environmental conditions. While evidence suggests that these biomes are alternative states, empirical broad-scale support to this hypothesis is still lacking. Using community-level field data and a novel resource-niche overlap approach, we show that, for a wide range of environmental conditions, fire feedbacks maintain savannas and forests as alternative biome states in both the Neotropics and the Afrotropics. In addition, wooded grasslands and savannas occurred as alternative grassy states in the Afrotropics, depending on the relative importance of fire and herbivory feedbacks. These results are consistent with landscape scale evidence and suggest that disturbance is a general factor driving and maintaining alternative biome states and vegetation mosaics in the tropics. © 2015 John Wiley & Sons Ltd/CNRS.

  17. Disturbance Distance: quantifying forests' vulnerability to disturbance under current and future conditions

    Science.gov (United States)

    Dolan, Katelyn A.; Hurtt, George C.; Flanagan, Steve A.; Fisk, Justin P.; Sahajpal, Ritvik; Huang, Chengquan; Le Page, Yannik; Dubayah, Ralph; Masek, Jeffrey G.

    2017-11-01

    Disturbances, both natural and anthropogenic, are critical determinants of forest structure, function, and distribution. The vulnerability of forests to potential changes in disturbance rates remains largely unknown. Here, we developed a framework for quantifying and mapping the vulnerability of forests to changes in disturbance rates. By comparing recent estimates of observed forest disturbance rates over a sample of contiguous US forests to modeled rates of disturbance resulting in forest loss, a novel index of vulnerability, Disturbance Distance, was produced. Sample results indicate that 20% of current US forestland could be lost if disturbance rates were to double, with southwestern forests showing highest vulnerability. Under a future climate scenario, the majority of US forests showed capabilities of withstanding higher rates of disturbance then under the current climate scenario, which may buffer some impacts of intensified forest disturbance.

  18. Extinction Risk in Successional Landscapes Subject to Catastrophic Disturbances

    Directory of Open Access Journals (Sweden)

    David Boughton

    2002-12-01

    Full Text Available We explore the thesis that stochasticity in successional-disturbance systems can be an agent of species extinction. The analysis uses a simple model of patch dynamics for seral stages in an idealized landscape; each seral stage is assumed to support a specialist biota. The landscape as a whole is characterized by a mean patch birth rate, mean patch size, and mean lifetime for each patch type. Stochasticity takes three forms: (1 patch stochasticity is randomness in the birth times and sizes of individual patches, (2 landscape stochasticity is variation in the annual means of birth rate and size, and (3 turnover mode is whether a patch is eliminated by disturbance or by successional change. Analytical and numerical analyses of the model suggest that landscape stochasticity is the most important agent. Landscape stochasticity increases the extinction risk to species by increasing the risk that the habitat will fluctuate to zero, by reducing the mean abundance of species, and by increasing the variance in species abundance. The highest risk was found to occur in species that inhabit patches with short lifetimes. The results of this general model suggest an important mechanism by which climate change threatens biodiversity: an increase in the frequency of extreme climate events will probably cause pulses of disturbance during some time periods; these in turn would cause wider fluctuations in annual disturbance rates and thus increase the overall level of landscape stochasticity. However, the model also suggests that humans can manipulate landscape stochasticity to reduce risk. In particular, if managed disturbances were more evenly distributed in time, attrition of the regional biota might be prevented. Other work on the connection between patch dynamics and extinction risk assumes the absence of landscape stochasticity and thus overlooks an important component of risk to biodiversity.

  19. Disturbance to wintering western snowy plovers

    Science.gov (United States)

    Lafferty, Kevin D.

    2001-01-01

    In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than at protected beaches. Wintering plovers reacted to disturbance at half the distance (∼40 m) as has been reported for breeding snowy plovers (∼80 m). Humans, dogs, crows and other birds were the main sources of disturbance on the public beach, and each snowy plover was disturbed, on average, once every 27 weekend min and once every 43 weekday min. Dogs off leash were a disproportionate source of disturbance. Plovers were more likely to fly from dogs, horses and crows than from humans and other shorebirds. Plovers were less abundant near trail heads. Over short time scales, plovers did not acclimate to or successfully find refuge from disturbance. Feeding rates declined with increased human activity. I used data from these observations to parameterize a model that predicted rates of disturbance given various management actions. The model found that prohibiting dogs and a 30 m buffer zone surrounding a 400 m stretch of beach provided the most protection for plovers for the least amount of impact to beach recreation.

  20. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... target. Species richness and functional diversity both increased in response to soil disturbance, and rotavation, but not ploughing, had a persistent positive effect on the occurrence of specialist species of calcareous sandy grassland. However, no type of soil disturbance caused the plant species...

  1. Influence of disturbance on temperate forest productivity

    Science.gov (United States)

    Peters, Emily B.; Wythers, Kirk R.; Bradford, John B.; Reich, Peter B.

    2013-01-01

    Climate, tree species traits, and soil fertility are key controls on forest productivity. However, in most forest ecosystems, natural and human disturbances, such as wind throw, fire, and harvest, can also exert important and lasting direct and indirect influence over productivity. We used an ecosystem model, PnET-CN, to examine how disturbance type, intensity, and frequency influence net primary production (NPP) across a range of forest types from Minnesota and Wisconsin, USA. We assessed the importance of past disturbances on NPP, net N mineralization, foliar N, and leaf area index at 107 forest stands of differing types (aspen, jack pine, northern hardwood, black spruce) and disturbance history (fire, harvest) by comparing model simulations with observations. The model reasonably predicted differences among forest types in productivity, foliar N, leaf area index, and net N mineralization. Model simulations that included past disturbances minimally improved predictions compared to simulations without disturbance, suggesting the legacy of past disturbances played a minor role in influencing current forest productivity rates. Modeled NPP was more sensitive to the intensity of soil removal during a disturbance than the fraction of stand mortality or wood removal. Increasing crown fire frequency resulted in lower NPP, particularly for conifer forest types with longer leaf life spans and longer recovery times. These findings suggest that, over long time periods, moderate frequency disturbances are a relatively less important control on productivity than climate, soil, and species traits.

  2. Disturbance size and severity covary in small and mid-size wind disturbances in Pennsylvania northern hardwoods forests

    Science.gov (United States)

    Chris J. Peterson; Lisa M. Krueger; Alejandro A. Royo; Scott Stark; Walter P. Carson

    2013-01-01

    Do large disturbances differ from small ones in characteristics other than size? The importance of disturbances in forest dynamics is unquestioned, and the size of the disturbed area (size of gap) is the most common way of differentiating disturbances. But few studies have examined other disturbance characteristics to see if small and large disturbances are different....

  3. The effects of memantine on behavioral disturbances in patients with Alzheimer's disease: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Kishi T

    2017-07-01

    Full Text Available Taro Kishi,* Shinji Matsunaga,* Nakao Iwata Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan *These authors contributed equally to this work Background: Memantine is effective in the treatment of behavioral disturbances in patients with Alzheimer’s disease. It has not yet been fully determined which behavioral disturbances respond best to memantine.Methods: We conducted a meta-analysis of memantine vs control (placebo or usual care for the treatment of individual behavioral disturbances (delusion, hallucination, agitation/aggression, dysphoria, anxiety/phobia, euphoria, apathy, disinhibition, irritability/lability, aberrant motor activity/activity disturbances, nighttime disturbance/diurnal rhythm disturbances, and eating disturbances. Randomized controlled studies of memantine in patients with Alzheimer’s disease were included in this study. To evaluate these outcomes, standardized mean difference (SMD, with 95% confidence intervals (95% CIs, based upon a random-effects model was evaluated in the meta-analysis.Results: A total of 11 studies (n=4,261; memantine vs placebo: N=4, n=1,500; memantine + cholinesterase inhibitors [M + ChEIs] vs ChEIs: N=7, n=2,761 were included in the meta-analysis. Compared to control, memantine showed significant improvement in agitation/aggression (SMD =-0.11; 95% CIs =-0.20, -0.03; P=0.01; I2=47%, delusion (SMD =-0.12; 95% CIs =-0.18, -0.06; P=0.0002; I2=0%, disinhibition (SMD =-0.08; 95% CIs =-0.15, -0.00; P=0.04; I2=0%, and nighttime disturbance/diurnal rhythm disturbances (SMD =-0.10; 95% CIs =-0.18, -0.02; P=0.02; I2=36%. Memantine was also marginally superior to control in hallucination (SMD =-0.06; 95% CIs =-0.12, 0.01; P=0.07; I2=0% and irritability/lability (SMD =-0.09; 95% CIs =-0.19, 0.01; P=0.07; I2=42%. Memantine is similar to control in dysphoria, anxiety/phobia, euphoria, apathy, and eating disturbance.Conclusion: The meta-analysis suggest

  4. Fractional active disturbance rejection control.

    Science.gov (United States)

    Li, Dazi; Ding, Pan; Gao, Zhiqiang

    2016-05-01

    A fractional active disturbance rejection control (FADRC) scheme is proposed to improve the performance of commensurate linear fractional order systems (FOS) and the robust analysis shows that the controller is also applicable to incommensurate linear FOS control. In FADRC, the traditional extended states observer (ESO) is generalized to a fractional order extended states observer (FESO) by using the fractional calculus, and the tracking differentiator plus nonlinear state error feedback are replaced by a fractional proportional-derivative controller. To simplify controller tuning, the linear bandwidth-parameterization method has been adopted. The impacts of the observer bandwidth ωo and controller bandwidth ωc on system performance are then analyzed. Finally, the FADRC stability and frequency-domain characteristics for linear single-input single-output FOS are analyzed. Simulation results by FADRC and ADRC on typical FOS are compared to demonstrate the superiority and effectiveness of the proposed scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Pancreatic disturbances and typhoid fever.

    Science.gov (United States)

    Hermans, P; Gerard, M; van Laethem, Y; de Wit, S; Clumeck, N

    1991-01-01

    During an 8-year period, 14 adult patients were hospitalized with typhoid fever confirmed by positive blood cultures for Salmonella typhi. Among these patients, we have retrospectively (n = 7) and prospectively (n = 7) evaluated pancreatic disturbance by serum amylase and lipase measurements at the time of admission. In 7 (50%) biological signs of pancreatitis were noted: mean amylase level 81 IU (range 30-201 IU, normal value less than 40 IU), mean lipase level 949 IU (range 468-2,000 IU, normal value less than 300 IU). Clinical signs of pancreatitis were observed in 4 cases, one of whom had a concomitant salmonella biliary tract infection and gall stones demonstrated by laparotomy and the others a normal biliary ultrasonographic examination with a swelling of the pancreas. No alcohol or drug use or other infection were noted before admission. This study suggests that biological or clinical pancreatitis should be considered as a frequent complication of typhoid fever. S. typhi should therefore be added to the list of pathogens implicated in the pathogenesis of non-alcoholic or non-lithiasic pancreatitis.

  6. Identity disturbance in distant patients.

    Science.gov (United States)

    Hoffman, Irwin

    2013-04-01

    Chronically distant, emotionally isolated patients often present with identity disturbance. Identity, it is argued, develops as a thematic pattern of narcissism, shaped by the nature of the mother's early libidinal influences on the child's sense of self. Identity provides a form of self-definition that addresses the question, Who am I? In the treatment of these patients, resistances to narcissistic vulnerabilities (narcissistic resistances) provide an illusory sense of security and induce the analyst to avoid attention to a central pathological problem: primitive and frightening needs for, and unconscious fantasies of, dependence on, and functionality for, another. Patients' avoidance of material and therapeutic interactions that deal with their dependencies are aspects of a tacit contract with the analyst to foreclose examination of their considerable problems with inner stability. Among these problems are anxieties regarding intrusion and loss of separateness. As analysis proceeds, elements of such a patient's identity become clarified and are used to understand and organize the material for both analyst and patient. This can allow the patient to articulate a more embodied and vital experience of individuality. A case is presented to illustrate the analysis of a patient using this approach.

  7. [Sleep disturbance in the elderly].

    Science.gov (United States)

    Mori, A

    1990-01-01

    Sleep structure is qualitatively and quantitatively changed by aging. The elderly usually go to bed in early evening and wake up in early morning, and they also take several naps in the day time. The polyphasic sleep is one of the typical sleep patterns found in the elderly. Comparing the sleep of the elderly with that of young adults by the method of polysomnography, the characteristics of the sleep of the elderly are in the prolongation of sleep latency, shortening of total sleep time, increase of Stage W and Stage 1, decrease of Stage 3 and 4, and also decrease of Stage REM and the advance of REM phase. Insomnia is a frequently observed symptom in the elderly. The so-called psychophysiological insomnia due to transient psychological or situational stress is common in the elderly. However, insomnia following the mental disturbance (depression), chronic use of drug or alcohol, dementia (vascular or Alzheimer type) are also important in the elderly. Sleep apnea syndrome is recently found as an important cause of insomnia. Concerning the treatment and prevention of insomnia, it is necessary to exclude the causes of insomnia, to improve the environmental conditions and to keep the regular rhythm of sleep-wake cycle. It is also important to carefully select and use the adequate hypnotics considering the pharmacokinetics and adverse effects of the drugs in the elderly.

  8. Instrumentation for Power System Disturbance Monitoring, Data ...

    African Journals Online (AJOL)

    In this paper, the level of instrumentation for power system disturbance monitoring, data acquisition and control in Nigerian Electric Power System; National Electric Power Authority (NEPA) is presented. The need for accurate power system disturbance monitoring is highlighted. A feature of an adequate monitoring, data ...

  9. The Dimensionality of Body Image Disturbance.

    Science.gov (United States)

    Galgan, Richard J.; And Others

    1987-01-01

    Examined personality variables in 75 male and 75 female college students. Found two dimensions underlying body image disturbance variables, one loading on body image dissatisfaction and one loading on body image disturbance. Low negative correlation between two factors suggests that distortion and dissatisfaction are fairly distinct and that body…

  10. A Full Disturbance Model for Reaction Wheels

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for

  11. Surface Disturbance Analysis in Rare Earth Mining

    Science.gov (United States)

    Li, H. K.; Yang, L.; Liu, Z. W.

    2017-02-01

    Mining ion-type rare-earth ore made the landscape and ecological environment degraded in mining area, and the tailing produced by rare-earth mining also led large areas land desertification, which resulted in surface temperature variations and significant differences in other types of mining disturbances. In order to analyse surface disturbance of rare-earth mining area, this paper applied the methods based on Normalized Difference Vegetation Index (NDVI) and Temperature different Coefficient (TDC) as the ecological disturbance indicator, compared and validated their applicability in Lingbei rare-earth mining area of Southern China. The results illustrated that, compared to NDVI, the TDC which reflected the characteristic of rare-earth mining technology has better discrimination of disturbance, especially for in-situ leach mining area. The places of tailing and the in-situ leach mining plants were the most dramatic mining disturbance. They had the biggest TDC value, followed by orchards and farmlands, reclamation plants, they had relatively small disturbance. And the last was the plant with the smallest TDC value. TDC in rare-earth mining could better correspond to the level of surface ecological disturbance. Therefore, TDC as the indicator of ecological disturbance factor had better performance than NDVI in rare-earth mining area.

  12. Prevalence Of Sleep Disturbances Among Primary Informal ...

    African Journals Online (AJOL)

    The general health questionnaire (GHQ) which is popularly used for screening for psychological distress was only able to pick out 53.3% of the caregivers with sleep disturbances. Amongst the caregivers, advancing age and belonging to a polygamous family setting were significantly associated with sleep disturbances.

  13. Pregabalin Improves Fibromyalgia-related Sleep Disturbance.

    Science.gov (United States)

    Roth, Thomas; Bhadra-Brown, Pritha; Pitman, Verne W; Resnick, E Malca

    2016-04-01

    To investigate the effect of pregabalin on wake and sleep bout parameters. A post hoc analysis of polysomnography data from a randomized, placebo-controlled, crossover study investigating the effect of pregabalin (150 to 450 mg/d) and placebo on sleep in fibromyalgia (FM). Eligible patients had FM and sleep-maintenance problems, including wake after sleep onset ≥45 minutes and total sleep time (TST) 3.0 to 6.5 hours, but no other sleep/circadian rhythm disorders. Polysomnography was performed for 2 consecutive nights (screening, post-treatment). Wake and sleep bout duration and frequency were derived; a "bout"=consecutive 30-s epochs of sleep or wake. Of 119 patients randomized (103 [87%] female), data were available for 103 treated with pregabalin and 106 with placebo. Pregabalin versus placebo treatment decreased mean±SD number of wake/sleep bouts (33.24±1.33 vs. 36.85±1.32; difference: -3.61 [95% confidence interval, -6.03, -1.18]; P=0.0039) and increased sleep bout duration (15.25±0.63 vs. 11.58±0.62 min; +3.67 min [2.22, 5.12 min]; PPregabalin decreased mean duration of wake bouts versus placebo (3.41±0.55 vs. 3.94±0.55 min; -0.53 min [-1.06, -0.002 min]; P=0.0493). An exploratory correlation analysis of treatment effects found stage 1 sleep was negatively correlated with wake and sleep bout duration and positively with wake/sleep bout number; slow wave sleep (%total sleep time) was positively correlated with wake and sleep bout duration and negatively with wake/sleep bout number. Pregabalin improved sleep parameters characteristic of disturbed sleep in FM, by preventing awakenings and increasing sleep bout duration. These effects are reflected in, and correlated with, a decrease in "light sleep" (stage 1) and an increase in "deep sleep" (slow wave sleep).

  14. Innovations in Practice: The relationship betweensleep disturbances, depression, and interpersonal functioning in treatment for adolescent depression.

    Science.gov (United States)

    McGlinchey, Eleanor L; Reyes-Portillo, Jazmin A; Turner, J Blake; Mufson, Laura

    2017-05-01

    Sleep disturbance is frequently comorbid with depression and sleep complaints are the most common residual symptoms after treatment among adolescents with depression. The present analyses investigated the effect of sleep disturbance in depressed adolescents treated with Interpersonal Psychotherapy for Adolescents (IPT-A) versus Treatment as Usual (TAU) in school-based mental health clinics. 63 adolescents participated in a randomized clinical trial of IPT-A versus TAU for adolescent depression. Participants were diagnosed with a DSM-IV depressive disorder and assessed for symptoms of depression, interpersonal functioning and sleep disturbance. Measures were assessed at baseline, session 4 and 8 of treatment, and session 12 for post-acute treatment follow-up. Hierarchical linear modeling (HLM) was used to model change in depression, interpersonal functioning and sleep disturbance. Ongoing sleep disturbance was significantly associated with worse depression scores as rated by clinician (γ = 1.04, SE = 0.22, p interpersonal functioning across the course of treatment (γ = 0.09, SE = 0.02, p interpersonal functioning for depressed adolescents. Sleep disturbance predicted more depression and interpersonal stress across treatments and led to a slower improvement in depression and interpersonal functioning. This data suggests that sleep disturbance should be a target for future treatment development research among depressed adolescents.

  15. The effect of the work environment on future sleep disturbances: a systematic review.

    Science.gov (United States)

    Linton, Steven J; Kecklund, Göran; Franklin, Karl A; Leissner, Lena C; Sivertsen, Børge; Lindberg, Eva; Svensson, Anna C; Hansson, Sven O; Sundin, Örjan; Hetta, Jerker; Björkelund, Cecilia; Hall, Charlotte

    2015-10-01

    Workers often attribute poor sleep to factors at work. Despite the large number of workers with sleep disturbances, there is a lack of consensus on the relationship between the work environment and sleep. The purpose of this systematic review therefore was to conduct a comprehensive evaluation. To this end, we employed standardized methods to systematically locate, review, and tabulate the results of prospective or randomized studies of the impact of work factors on sleep disturbances. From the 7981 articles located in five databases, 24 fulfilled our inclusion criteria and formed the base of the review including meta-analyses of the effect sizes. Results showed that the psychosocial work variables of social support at work, control, and organizational justice were related to fewer sleep disturbances, while high work demands, job strain, bullying, and effort-reward imbalance were related to more future sleep disturbances. Moreover, working a steady shift was associated with disturbances while exiting shift work was associated with less disturbed sleep. We conclude that psychosocial work factors and the scheduling of work have an impact on sleep disturbances and this might be utilized in the clinic as well as for planning work environments. Future research needs to employ better methodology and focus on underlying mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Prevalence of sleep disturbances in Chinese university students: a comprehensive meta-analysis.

    Science.gov (United States)

    Li, Lu; Wang, Yuan-Yuan; Wang, Shi-Bin; Zhang, Ling; Li, Lin; Xu, Dan-Dan; Ng, Chee H; Ungvari, Gabor S; Cui, Xiling; Liu, Zhao-Min; De Li, Spencer; Jia, Fu-Jun; Xiang, Yu-Tao

    2018-01-31

    This is a meta-analysis of the pooled prevalence of sleep disturbances and its associated factors in Chinese university students. English (PubMed, PsycINFO, Embase) and Chinese (SinoMed, Wan Fang Database and Chinese National Knowledge Infrastructure) databases were systematically and independently searched from inception until 16 August 2016. The prevalence of sleep disturbances was pooled using random-effects model. Altogether 76 studies involving 112 939 university students were included. The overall pooled prevalence of sleep disturbances was 25.7% (95% CI: 22.5-28.9%). When using the screening scales Pittsburgh Sleep Quality Index, Athens Insomnia Scale and Self-Rating Sleeping State Scale, and the diagnostic criteria of the Chinese Classification of Mental Disorders (Second Edition), the pooled prevalence of sleep disturbances was 24.1% (95% CI: 21.0-27.5%) and 18.1% (95% CI: 16.4-20.0%), respectively. The percentages of students dissatisfied with sleep quality and those suffering from insomnia symptoms were 20.3% (95% CI: 13.0-30.3%) and 23.6% (95% CI: 18.9-29.0%), respectively. Subgroup analyses revealed that medical students were more vulnerable to sleep disturbances than other student groups. There was no significant difference between males and females, and across geographic locations. Sleep disturbances are common in Chinese university students. Appropriate strategies for prevention and treatment of sleep disturbances in this population need greater attention. © 2018 European Sleep Research Society.

  17. Hydrological disturbance diminishes predator control in wetlands.

    Science.gov (United States)

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  18. Interventions for managing taste disturbances.

    Science.gov (United States)

    Kumbargere Nagraj, Sumanth; George, Renjith P; Shetty, Naresh; Levenson, David; Ferraiolo, Debra M; Shrestha, Ashish

    2017-12-20

    The sense of taste is very much essential to the overall health of an individual. It is a necessary component to enjoy one's food, which in turn provides nutrition to an individual. Any disturbance in taste perception can hamper quality of life in such patients by influencing their appetite, body weight and psychological well-being. Taste disorders have been treated using different modalities of treatment and there is no consensus for the best intervention. Hence this Cochrane Review was undertaken. This is an update of the Cochrane Review first published in November 2014. To assess the effects of interventions for the management of patients with taste disturbances. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 4 July 2017); the Cochrane Central Register of Controlled Trials (CENTRAL; 2017 Issue 6) in the Cochrane Library (searched 4 July 2017); MEDLINE Ovid (1946 to 4 July 2017); Embase Ovid (1980 to 4 July 2017); CINAHL EBSCO (1937 to 4 July 2017); and AMED Ovid (1985 to 4 July 2017). The US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for trials. Abstracts from scientific meetings and conferences were searched on 25 September 2017. No restrictions were placed on the language or date of publication when searching the electronic databases. We included all randomised controlled trials (RCTs) comparing any pharmacological agent with a control intervention or any non-pharmacological agent with a control intervention. We also included cross-over trials in the review. Two pairs of review authors independently, and in duplicate, assessed the quality of trials and extracted data. Wherever possible, we contacted trial authors for additional information. We collected adverse events information from the trials. We included 10 trials (581 participants

  19. Disturbed Fossil Group Galaxy NGC 1132

    Science.gov (United States)

    Kim, Dong-Woo; Anderson, Craig; Burke, Doug; Fabbiano, Giuseppina; Fruscione, Antonella; Lauer, Jen; McCollough, Michael; Morgan, Doug; Mossman, Amy; O’Sullivan, Ewan; Paggi, Alessandro; Vrtilek, Saeqa; Trinchieri, Ginevra

    2018-02-01

    We have analyzed the Chandra archival data of NGC 1132, a well-known fossil group, i.e., a system expected to be old and relaxed long after the giant elliptical galaxy assembly. Instead, the Chandra data reveal that the hot gas morphology is disturbed and asymmetrical, with a cold front following a possible bow shock. We discuss possible origins of the disturbed hot halo, including sloshing by a nearby object, merger, ram pressure by external hotter gas, and nuclear outburst. We consider that the first two mechanisms are likely explanations for the disturbed hot halo, with a slight preference for a minor merger with a low impact parameter because of the match with simulations and previous optical observations. In this case, NGC 1132 may be a rare example of unusual late mergers seen in recent simulations. Regardless of the origin of the disturbed hot halo, the paradigm of the fossil system needs to be reconsidered.

  20. Sleep Disturbances Associated with Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Keisuke Suzuki

    2011-01-01

    Full Text Available Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD.

  1. Depression, Anxiety, and Disturbed Sleep in Glaucoma

    National Research Council Canada - National Science Library

    Agorastos, Agorastos; Skevas, Christos; Matthaei, Mario; Otte, Christian; Klemm, Maren; Richard, Gisbert; Huber, Christian G

    2013-01-01

    ... of “circadian misalignment,” sleep disorders, anxiety, and depression. Patients with severe glaucoma, versus glaucoma patients without visual-field defects, showed higher comorbidity with trait-anxiety, depression, and sleep disturbance...

  2. Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS)

    Science.gov (United States)

    Masek, Jeffrey G.

    2006-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project is creating a record of forest disturbance and regrowth for North America from the Landsat satellite record, in support of the carbon modeling activities. LEDAPS relies on the decadal Landsat GeoCover data set supplemented by dense image time series for selected locations. Imagery is first atmospherically corrected to surface reflectance, and then change detection algorithms are used to extract disturbance area, type, and frequency. Reuse of the MODIS Land processing system (MODAPS) architecture allows rapid throughput of over 2200 MSS, TM, and ETM+ scenes. Initial ("Beta") surface reflectance products are currently available for testing, and initial continental disturbance products will be available by the middle of 2006.

  3. Sleep disturbances after non-cardiac surgery

    DEFF Research Database (Denmark)

    Rosenberg, Jacob

    2001-01-01

    After major non-cardiac surgery sleep pattern is usually disturbed with initial suppression of rapid eye movement sleep with a subsequent rebound during the first post-operative week. Deep sleep is also suppressed for several days after the operation and subjective sleep quality is impaired....... The sleep disturbances seem to be related to the magnitude of trauma and thereby to the surgical stress response and/or post-operative opioid administration. Post-operative sleep disturbances may contribute to the development of early post-operative fatigue, episodic hypoxaemia, haemodynamic instability...... and altered mental status, all with a potential negative effect on post-operative outcome. Minimizing surgical trauma and avoiding or minimizing use of opioids for pain relief may prevent or reduce post-operative sleep disturbances. Post-operative sleep pattern represents an important research field, since...

  4. Evolution of disturbances in stagnation point flow

    Science.gov (United States)

    Criminale, William O.; Jackson, Thomas L.; Lasseigne, D. Glenn

    1993-01-01

    The evolution of three-dimensional disturbances in an incompressible three-dimensional stagnation-point flow in an inviscid fluid is investigated. Since it is not possible to apply classical normal mode analysis to the disturbance equations for the fully three-dimensional stagnation-point flow to obtain solutions, an initial-value problem is solved instead. The evolution of the disturbances provide the necessary information to determine stability and indeed the complete transient as well. It is found that when considering the disturbance energy, the planar stagnation-point flow, which is independent of one of the transverse coordinates, represents a neutrally stable flow whereas the fully three-dimensional flow is either stable or unstable, depending on whether the flow is away from or towards the stagnation point in the transverse direction that is neglected in the planar stagnation point.

  5. Wind Power Prediction Considering Nonlinear Atmospheric Disturbances

    Directory of Open Access Journals (Sweden)

    Yagang Zhang

    2015-01-01

    Full Text Available This paper considers the effect of nonlinear atmospheric disturbances on wind power prediction. A Lorenz system is introduced as an atmospheric disturbance model. Three new improved wind forecasting models combined with a Lorenz comprehensive disturbance are put forward in this study. Firstly, we define the form of the Lorenz disturbance variable and the wind speed perturbation formula. Then, different artificial neural network models are used to verify the new idea and obtain better wind speed predictions. Finally we separately use the original and improved wind speed series to predict the related wind power. This proves that the corrected wind speed provides higher precision wind power predictions. This research presents a totally new direction in the wind prediction field and has profound theoretical research value and practical guiding significance.

  6. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  7. Sleep, Sleep Disturbance and Fertility in Women

    Science.gov (United States)

    Kloss, Jacqueline D.; Perlis, Michael; Zamzow, Jessica; Culnan, Elizabeth; Gracia, Clarisa

    2014-01-01

    Summary Sleep and sleep disturbances are increasingly recognized as determinants of women’s health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible. PMID:25458772

  8. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  9. Ursus arctos : ethology and anthropogenic disturbances

    OpenAIRE

    Duran Tapia, Joana

    2015-01-01

    Brown bear (Ursus arctos) is a typically solitary mammal. Because of this and its elusiveness, its ethology is difficult to study and is not still completely understood. Brown bear’s behavior is highly influenced by some of its reproductive characteristics and, increasingly, by anthropogenic disturbance. Thus, it is important to analyse the impact of anthropogenic disturbance on brown bear’s ethology and to develop management strategies to minimize negative impacts.

  10. Hypercalcemia and electrolyte disturbances in malignancy.

    Science.gov (United States)

    Barri, Y M; Knochel, J P

    1996-08-01

    Hypercalcemia and electrolyte abnormalities are common problems in patients with malignancy. In this article we discuss the pathophysiology, clinical features, and management of hypercalcemia, which is the most common metabolic abnormality. We also analyze the electrolyte disturbances that occur in association with malignancy, including hyponatremia, hypokalemia, hypomagnesemia, hypophosphatemia, and hyperkalemia. Recognition and treatment of these disturbances are important parts of the management of patients with malignant disease.

  11. Sleep disturbances and exposure to organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Lindelof, B.; Almkvist, O.; Goethe, C. (Huddinge Hospital (Sweden))

    An inquiry about sleep habits and sleep disturbances revealed a significantly higher prevalence of insomnia in a solvent-exposed group than in a comparable group that had no occupational exposure to organic solvents. The solvent-exposed group has also registered an increased consumption of hypnotics, and a significant increase occurred in the number of individuals who had consulted physicians because of sleep disorders. The results indicate that solvent exposure could induce sleep disturbances.

  12. Sleep disturbance associated factors in menopausal women

    Directory of Open Access Journals (Sweden)

    Hamid Haghani

    2011-09-01

    Full Text Available Background: Sleep is necessary in life and approximately 1/3 of human life is devoted to sleep. One of the most common problems in menopausal women is sleep disturbance. The aim of this study was to determine frequency of sleep disorders and its related factors in 50 – 60 years old women Methods: A cross-sectional, descriptive study was conducted on 200 eligible women who referred to selected health centers of Tehran University of Medical Sciences (TUMS. Demographic form, ten-point slide to review sexual satisfaction and Pittsburg Sleep Quality Index Questioner (PSQI were used for data collection. Data was analyzed using ANOVA, t-test, and Pearson correlation tests.Results: The mean age of women was 53.6±3.6 year, menopause age 47.8±4, number of children 4.76±2 and partner age was 57.99±6.6. 34.5% of women were satisfied from their sexual relationship and their score was 8-10. Rate of sleep disturbances in this group was about 70%. The results showed that between four variables: economical status, occupation, partner occupation and educational status were significantly associated with sleep disturbance (P=0.002. There was not significant difference between other demographic information and sleep disturbance.Conclusion: The results show high prevalence of sleep disturbance symptoms among menopausal women. According to the relationship between some personal characters and sleep disturbance, health care providers need to consider these variables.

  13. Concepts and Challenges in Disturbance Hydrology

    Science.gov (United States)

    Ebel, B. A.; Mirus, B. B.

    2016-12-01

    Landscape disturbances are increasing, often promoted and enhanced by climate shifts and human activities. Insect infestations, wildfires, earthquakes, urban development, forest harvest, mineral and petroleum resource extraction, and hurricanes are common landscape disturbances that can have profound hydrologic consequences. These cause relatively abrupt changes in the landscape, which alter local processes on plots and hillslopes in addition to coarser-scale processes across watersheds through cross-scale interactions. Shifts in soil properties and cover of vegetation and leaf litter change the water storage or buffering capacity as well as the hydrologic functional connectivity across multiple scales. These changes increase the risk of catastrophic flooding, erosion, and mass movements that degrade water resources, ecosystem services, and protection from hydrologically driven natural hazards. Although it is imperative that we understand the hydrologic effects of these disturbances, several major barriers exist. Four challenges are: (i) overlapping disturbances in space and time with unknown recovery trajectories, (ii) a paucity of long-term recovery records (>5 years duration), (iii) inefficacy of traditional modeling and parameterization approaches, and (iv) lack of pre-disturbance characterization. Examples of these challenges will be presented along with proposed opportunities for improved mechanistic understanding of processes and thresholds in disturbance hydrology.

  14. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  15. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  16. Improving sleep quality interventions among menopausal women with sleep disturbances in Taiwan: a preliminary study.

    Science.gov (United States)

    Hsu, Hsiu-Chin; Tsao, Lee-Ing; Lin, Mei-Hsiang

    2015-11-01

    The aim of this study was to evaluate the effectiveness of improving sleep quality interventions in menopausal women with sleep disturbance. Sleep disturbances are an extensive and common problem among menopausal women. There is an increased trend in the use of non-pharmacological methods to alleviate sleep disturbances. Studies that have implemented two or more non-pharmacological strategies for menopausal women are scant. A repeat measurement with a randomized assignment was conducted. A total of 59 menopausal women with sleep disturbance were recruited and randomly assigned to experimental (n = 29) and control (n = 30) groups. Participants in the experimental group received four 2-hour improving sleep quality activities, whereas the control group received regular greeting calls. Sleep quality was measured prior to intervention, and on the 5th and 8th weeks by using the Pittsburg's Sleep Quality Index, and Actiwatch was worn before and during the 8 weeks of intervention. Generalized estimating equation was used to analyze data. The results revealed that subjective sleep quality had significant main effect in group and time. The findings of the objective measurement showed that participants in the experimental group had significantly shorter frequency of awakening time and increased sleep efficiency. The improving sleep quality intervention is a healthy and cost-effective method to improve sleep quality in community-dwelling menopausal women with sleep disturbance. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Activity disturbances caused by different environmental noises

    Science.gov (United States)

    Åhrlin, U.

    1988-12-01

    An analysis was made of data obtained in investigations performed on annoyance reactions due to noise from aircraft, trains and road traffic. The aims of the analysis were to study the covariation between the extent of activity disturbances and general annoyance, to compare different noise sources with reference to activity disturbances caused, and to study the relation between the extent of annoyance reactions and noise exposure. The activity disturbances studied were speech interference effects, adverse effects on rest and sleep and awakening. Common to all three noise sources is that the extent of all activity disturbances increased with increased general annoyance. However, the rank order between the effects was different. In areas exposed to aircraft and train noise, speech interference was the effect reported by the largest proportion of respondents. Road traffic noise primarily disturbed rest and sleep. As regards train noise, it was demonstrated that although the extent of activity disturbances was comparatively high, the extent of general annoyance was lower on the whole than the extent of activity disturbances. These differences in responses may be due to differences in attitudes towards the noise sources. Even though actual noise-related effects were experienced, the degree of subjective annoyance may be determined by the type of noise source causing the effects. The dose-response relationship established for aircraft and train noise demonstrated that the extent of general annoyance varied although the noise conditions were similar. The differences were further accentuated with increasing dB(A) levels. The results from the analysis demonstrated that the use of response indices based upon different activity interferences must take into account the variations that are present between different noise sources. Weighting all activity interferences into an index and applying this universally for all noises will decrease the precision of the response

  18. Does regional diversity recover after disturbance? A field experiment in constructed ponds

    Science.gov (United States)

    Woods, Lauren M.; Biro, Elizabeth G.; Yang, Muxi

    2016-01-01

    The effects of disturbance on local species diversity have been well documented, but less recognized is the possibility that disturbances can alter diversity at regional spatial scales. Since regional diversity can dictate which species are available for recolonization of degraded sites, the loss of diversity at regional scales may impede the recovery of biodiversity following a disturbance. To examine this we used a chemical disturbance of rotenone, a piscicide commonly used for fish removal in aquatic habitats, on small fishless freshwater ponds. We focused on the non-target effects of rotenone on aquatic invertebrates with the goal of assessing biodiversity loss and recovery at both local (within-pond) and regional (across ponds) spatial scales. We found that rotenone caused significant, large, but short-term losses of species at both local and regional spatial scales. Using a null model of random extinction, we determined that species were selectively removed from communities relative to what would be expected if species loss occurred randomly. Despite this selective loss of biodiversity, species diversity at both local and regional spatial scales recovered to reference levels one year after the addition of rotenone. The rapid recovery of local and regional diversity in this study was surprising considering the large loss of regional species diversity, however many aquatic invertebrates disperse readily or have resting stages that may persist through disturbances. We emphasize the importance of considering spatial scale when quantifying the impacts of a disturbance on an ecosystem, as well as considering how regional species loss can influence recovery from disturbance. PMID:27781153

  19. Work-family conflict and sleep disturbance: the Malaysian working women study.

    Science.gov (United States)

    Aazami, Sanaz; Mozafari, Mosayeb; Shamsuddin, Khadijah; Akmal, Syaqirah

    2016-01-01

    This study aimed at assessing effect of the four dimensions of work-family conflicts (strain and time-based work interference into family and family interference into work) on sleep disturbance in Malaysian working women. This cross-sectional study was conducted among 325 Malaysian married working women. Multiple-stage simple random sampling method was used to recruit women from public service departments of Malaysia. Self-administrated questionnaires were used to measure the study variables and data were analyzed using SPSS version 21. We found that high level of the four dimensions of work-family conflicts significantly increase sleep disturbance. Our analyses also revealed an age-dependent effect of the work-family conflict on sleep disturbance. Women in their 20 to 30 yr old suffer from sleep disturbance due to high level of time-based and strain-based work-interference into family. However, the quality of sleep among women aged 30-39 were affected by strain-based family-interference into work. Finally, women older than 40 yr had significantly disturbed sleep due to strain-based work-interference into family as well as time-based family interference into work. Our findings showed that sleep quality of working women might be disturbed by experiencing high level of work-family conflict. However, the effects of inter-role conflicts on sleep varied among different age groups.

  20. Dynamic surface tracking controller design for a constrained hypersonic vehicle based on disturbance observer

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-05-01

    Full Text Available The tracking control problem of a flexible air-breathing hypersonic vehicle subjects to aerodynamic parameter uncertainty and input constraint is investigated by combining nonlinear disturbance observer and dynamic surface control. To design controller simply, a control-oriented model is firstly derived and divided into two subsystems, velocity subsystem and altitude subsystem based on the engineering backgrounds of flexible air-breathing hypersonic vehicle. In every subsystem, compounded disturbances are included to consider aerodynamic uncertainty and the effect of the flexible modes. Then, disturbance observer is not only used to handle the compounded disturbance but also to handle the input constraint, where the estimation error converges to a random small region through appropriately choosing the observer parameters. To sequel, the disturbance observer–based robust control scheme and the disturbance observer-based dynamic surface control scheme are developed for the velocity subsystem and altitude subsystem, respectively. Besides, novel filters are designed to alleviate the problem of “explosion of terms” induced by backstepping method. On the basis of Lyapunov stability theory, the presented control scheme can assure that tracking error converges to an arbitrarily small neighborhood around zero by rigorous theoretical analysis. At last, simulation result shows the effectiveness of the presented control method.

  1. Active disturbance rejection controller for chemical reactor

    Energy Technology Data Exchange (ETDEWEB)

    Both, Roxana; Dulf, Eva H.; Muresan, Cristina I., E-mail: roxana.both@aut.utcluj.ro [Technical University of Cluj-Napoca, 400114 Cluj-Napoca (Romania)

    2015-03-10

    In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However the resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method.

  2. Robust fuzzy logic stabilization with disturbance elimination.

    Science.gov (United States)

    Danapalasingam, Kumeresan A

    2014-01-01

    A robust fuzzy logic controller is proposed for stabilization and disturbance rejection in nonlinear control systems of a particular type. The dynamic feedback controller is designed as a combination of a control law that compensates for nonlinear terms in a control system and a dynamic fuzzy logic controller that addresses unknown model uncertainties and an unmeasured disturbance. Since it is challenging to derive a highly accurate mathematical model, the proposed controller requires only nominal functions of a control system. In this paper, a mathematical derivation is carried out to prove that the controller is able to achieve asymptotic stability by processing state measurements. Robustness here refers to the ability of the controller to asymptotically steer the state vector towards the origin in the presence of model uncertainties and a disturbance input. Simulation results of the robust fuzzy logic controller application in a magnetic levitation system demonstrate the feasibility of the control design.

  3. Ionospheric irregularities in periods of meteorological disturbances

    Science.gov (United States)

    Borchevkina, O. P.; Karpov, I. V.

    2017-09-01

    The results of observations of the total electron content (TEC) in periods of storm disturbances of meteorological situation are presented in the paper. The observational results have shown that a passage of a meteorological storm is accompanied by a substantial decrease in values of TEC and critical frequencies of the ionospheric F2 region. The decreases in values of these ionospheric parameters reach 50% and up to 30% in TEC and critical frequency of the F2 layer, respectively, as compared to meteorologically quiet days. Based on qualitative analysis, it is found that the processes related to formation of local regions of thermospheric heating due to a dissipation of AGW coming into the upper atmosphere from the region of the meteorological disturbance in the lower atmosphere are a possible cause of these ionospheric disturbances.

  4. Work Time Control and Sleep Disturbances

    DEFF Research Database (Denmark)

    Salo, Paula; Ala-Mursula, Leena; Rod, Naja Hulvej

    2014-01-01

    OBJECTIVES: Employee control over work times has been associated with favorable psychosocial and health-related outcomes, but the evidence regarding sleep quality remains inconclusive. We examined cross-sectional and prospective associations between work time control and sleep disturbances...... in a large working population, taking into account total hours worked. METHODS: The data were from a full-panel longitudinal cohort study of Finnish public sector employees who responded to questions on work time control and sleep disturbances in years 2000-2001, 2004-2005, 2008-2009, and 2012. The analysis....... RESULTS: Consistently in both cross-sectional and longitudinal models, less control over work time was associated with greater sleep disturbances in the total population and among those working normal 40-hour weeks. Among participants working more than 40 hours a week, work time that was both very high...

  5. [Sleep rhythm disturbances in Alzheimer's disease].

    Science.gov (United States)

    Onen, F; Onen, S-H

    2003-03-01

    Sleep-wake rhythm disturbances observed in Alzheimer's disease are correlated with the severity of cognitive impairment and often result in institutionalization. These disturbances are also a major cause of psychotropic medication misuse. We report age-related physiologic and disease related pathologic changes in sleep-wake rhythms and propose chronobiological treatment approaches in patients with Alzheimer's disease. Alzheimer patients show a greater breakdown of the circadian sleep-wake cycle compared to similarly aged non demented controls. Demented patients spend their nights in a state of frequent restlessness and their days in a state of frequent sleepiness. These sleep-wake disturbances became increasingly more marked with progression of the disease. The architecture of sleep in Alzheimer's disease is marked by further decreases of slow wave sleep (SWS) and rapid eye movement (REM) sleep, and increases of time and frequency of awakening compared to age-matched control subjects. The sleep-wake disturbances in elderly people and particularly Alzheimer patients may result from changes at different levels: a reduction of environmental synchronizers or their perception, a lack of mental and physical activity, an age or disease related anatomical changes with loss of functionality of the biological clock(s). In Alzheimer patients, controlling sleep-wake disturbances with sedative drugs often increases both sleep disturbance and cognitive dysfunction. A chronobiological approach with bright-light therapy, melatonin administration, restricted time in bed, and diurnal activity may be an interesting therapeutic alternative in the management of sleep-wake disorders in Alzheimer patients. The aim of these therapeutics is to improve sleep and diurnal activity and consequently to increase the quality of life in Alzheimer patients.

  6. Disturbance ecology and forest management: A review of the literature

    Science.gov (United States)

    Paul Rogers

    1996-01-01

    This review of the disturbance ecology literature, and how it pertains to forest management, is a resource for forest managers and researchers interested in disturbance theory, specific disturbance agents, their interactions, and appropriate methods of inquiry for specific geographic regions. Implications for the future of disturbance ecology-based management are...

  7. Disturbances in reaction wheels; from measurement to modelling

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Disturbances in reaction wheels have been long a crucial aspect for many scientific observation missions. An accurate and reliable disturbance model to understand and evaluate the influence of reaction wheel disturbances to the spacecraft is critically needed. Several reaction wheel disturbance

  8. North American forest disturbance mapped from a decadal Landsat record

    Science.gov (United States)

    Jeffrey G. Masek; Chengquan Huang; Robert Wolfe; Warren Cohen; Forrest Hall; Jonathan Kutler; Peder. Nelson

    2008-01-01

    Forest disturbance and recovery are critical ecosystem processes, but the spatial pattern of disturbance has never been mapped across North America. The LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project has assembled a wall-to-wall record of stand-clearing disturbance (clearcut harvest, fire) for the United States and Canada for the period 1990-...

  9. Patterns of diversity along experimental gradients of disturbance ...

    African Journals Online (AJOL)

    A model of the interactive effects of disturbance and productivity on diversity predicts peak diversity to shift towards higher disturbance regimes as productivity increases, confining the Intermediate Disturbance Hypothesis to intermediate productivity levels. We conducted a two-factorial (disturbance, nutrients) field ...

  10. Sudden ionospheric disturbances in solar cycle 24

    Science.gov (United States)

    Bothmer, Volker; Bernert, Barbara

    2014-05-01

    Sudden ionospheric disturbances in solar cycle 24 Within the framework of the UN International Space Weather Initiative, and building upon the achievements of the International Heliophysical Year, the German project SIMONE (Sun Ionosphere MOnitoring NEtwork) operates several SID monitors provided by the University of Stanford. Here we present an overview of sudden ionospheric disturbances recorded since 2006 at the high school Gymnasium Walsrode until to date. The continous measurements allow a detailed comparison of locally measured SIDs with the general trend of solar activity during the current solar maximum. We further show that the measurements reveal specific information on the variable response of the dayside ionosphere to solar flares.

  11. Voriconazole-associated visual disturbances and hallucinations.

    Science.gov (United States)

    Bayhan, Gulsum Iclal; Garipardic, Mesut; Karaman, Kamuran; Akbayram, Sinan

    2016-03-01

    Voriconazole is a second-generation azole widely used for the prevention and treatment of fungal infection in leukemia patients. Voriconazole is considered the primary antifungal agent for invasive aspergillosis. We report a case of 16-year-old girl who developed visual disturbance and visual and auditory hallucinations after intravenous voriconazole treatment for invasive pulmonary aspergillosis. Due to the visual hallucinations and visual disturbance began acutely and shortly after the initiation of voriconazole, and no other cause could be determined, the symptoms were considered to be the side effects of voriconazole. Simultaneous development of visual side effects and hallucinations rarely have been reported before.

  12. PID control with robust disturbance feedback control

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Vinther, Kasper; Andersen, Palle

    2015-01-01

    Disturbance Feedback Control (DFC) is a technique, originally proposed by Fuji Electric, for augmenting existing control systems with an extra feedback for attenuation of disturbances and model errors. In this work, we analyze the robustness and performance of a PID-based control system with DFC...... and performance (if such gains exist). Finally, two different simulation case studies are evaluated and compared. Our numerical studies indicate that better performance can be achieved with the proposed method compared with a conservatively tuned PID controller and comparable performance can be achieved when...... compared with an H-infinity controller....

  13. Nonunity gain minimal-disturbance measurement

    DEFF Research Database (Denmark)

    Sabuncu, Metin; Mišta, L.; Fiurášek, J.

    2007-01-01

    We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes and to...... and to the output state, respectively. We derive the optimal trade-off relation between the two noises and we show that the tradeoff is saturated by nonunity gain teleportation. Optimal partial measurement is demonstrated experimentally using a linear optics scheme with feedforward....

  14. Circadian Rhythm Disturbances in Patients with Alzheimer's Disease: A Review

    Directory of Open Access Journals (Sweden)

    Dawit A. Weldemichael

    2010-01-01

    Full Text Available Circadian Rhythm Disturbances (CRDs affect as many as a quarter of Alzheimer's disease (AD patients during some stage of their illness. Alterations in the suprachiasmatic nucleus and melatonin secretion are the major factors linked with the cause of CRDs. As a result, the normal physiology of sleep, the biological clock, and core body temperature are affected. This paper systematically discusses some of the causative factors, typical symptoms, and treatment options for CRDs in patients with AD. This paper also emphasizes the implementation of behavioral and environmental therapies before embarking on medications to treat CRDs. Pharmacotherapeutic options are summarized to provide symptomatic benefits for the patient and relieve stress on their families and professional care providers. As of today, there are few studies relative to CRDs in AD. Large randomized trials are warranted to evaluate the effects of treatments such as bright light therapy and engaging activities in the reduction of CRDs in AD patients.

  15. Age structure and disturbance legacy of North American forests

    OpenAIRE

    Y. Pan; J. M. Chen; R. Birdsey; K. McCullough; L. He; F. Deng

    2010-01-01

    Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stock and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is the most available...

  16. Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial.

    LENUS (Irish Health Repository)

    Hurley, Deirdre A

    2010-01-01

    Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population.

  17. Disturbance effect of music on processing of verbal and spatial memories.

    Science.gov (United States)

    Iwanaga, Makoto; Ito, Takako

    2002-06-01

    The purpose of the present study was to examine the disturbance effect of music on performances of memory tasks. Subjects performed a verbal memory task and a spatial memory task in 4 sound conditions, including the presence of vocal music, instrumental music, a natural sound (murmurings of a stream), and no music. 47 undergraduate volunteers were randomly assigned to perform tasks under each condition. Perceived disturbance was highest under the vocal music condition regardless of the type of task. A disturbance in performance by music was observed only with the verbal memory task under the vocal and the instrumental music conditions. These findings were discussed from the perspectives of the working memory hypothesis and the changing state model.

  18. Disturbance rejection performance analyses of closed loop control systems by reference to disturbance ratio.

    Science.gov (United States)

    Alagoz, Baris Baykant; Deniz, Furkan Nur; Keles, Cemal; Tan, Nusret

    2015-03-01

    This study investigates disturbance rejection capacity of closed loop control systems by means of reference to disturbance ratio (RDR). The RDR analysis calculates the ratio of reference signal energy to disturbance signal energy at the system output and provides a quantitative evaluation of disturbance rejection performance of control systems on the bases of communication channel limitations. Essentially, RDR provides a straightforward analytical method for the comparison and improvement of implicit disturbance rejection capacity of closed loop control systems. Theoretical analyses demonstrate us that RDR of the negative feedback closed loop control systems are determined by energy spectral density of controller transfer function. In this manner, authors derived design criteria for specifications of disturbance rejection performances of PID and fractional order PID (FOPID) controller structures. RDR spectra are calculated for investigation of frequency dependence of disturbance rejection capacity and spectral RDR analyses are carried out for PID and FOPID controllers. For the validation of theoretical results, simulation examples are presented. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Conical shell edge disturbance : An engineer's derivation

    NARCIS (Netherlands)

    Blaauwendraad, J.; Hoefakker, JH

    2016-01-01

    Because a rigorous bending theory for thin shells of revolution is complicated, attempts have been made for reliable approximations of the edge disturbance problem under axisymmetric loading. A well-known one was published by Geckeler [1, 2], who obtained his approximation by mathematical

  20. Disturbing Practices: Training Workers to Be Lean

    Science.gov (United States)

    Yasukawa, Keiko; Brown, Tony; Black, Stephen

    2014-01-01

    Purpose: The purpose of this paper is to explore the possibilities for expansive learning during organisational change. It considers the introduction of "lean production" as a disturbance to the existing work practices. Design/methodology/approach: The paper considers two case studies of "lean production" training with…

  1. Neurobiology of sleep disturbances in neurodegenerative disorders.

    Science.gov (United States)

    Gagnon, J-F; Petit, D; Latreille, V; Montplaisir, J

    2008-01-01

    This review presents sleep disturbances and their underlying pathophysiology in three categories of neurodegenerative disorders namely tauopathies, synucleinopathies, and Huntington's disease (HD) and prion-related diseases. Sleep abnormalities are a major and early feature of neurodegenerative disorders, especially for synucleinopathies, HD and prion-related diseases, in which the sleep-related brainstem regions are severely altered and impaired sooner than in most of the tauopathies. In synucleinopathies, HD and prion-related diseases, specific sleep disturbances, different from those observed in tauopathies, are considered as core manifestations of the disease and in some cases, as preclinical signs. For this reason, the evaluation of sleep components in these neurodegenerative disorders may be useful to make a diagnosis and to assess the efficacy of pharmacotherapy. Since sleep disruption may occur early in the course of neurodegeneration, sleep disturbance may serve as groundwork to study the efficacy of neuroprotective agents to prevent or delay the development of a full-blown neurodegenerative disorder. The cause of sleep disturbances in neurodegenerative disorders may be attributed to several factors, including age-related modifications, symptoms of the disease, comorbid conditions and the neurodegenerative process itself.

  2. Alerts of forest disturbance from MODIS imagery

    Science.gov (United States)

    Hammer, Dan; Kraft, Robin; Wheeler, David

    2014-12-01

    This paper reports the methodology and computational strategy for a forest cover disturbance alerting system. Analytical techniques from time series econometrics are applied to imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to detect temporal instability in vegetation indices. The characteristics from each MODIS pixel's spectral history are extracted and compared against historical data on forest cover loss to develop a geographically localized classification rule that can be applied across the humid tropical biome. The final output is a probability of forest disturbance for each 500 m pixel that is updated every 16 days. The primary objective is to provide high-confidence alerts of forest disturbance, while minimizing false positives. We find that the alerts serve this purpose exceedingly well in Pará, Brazil, with high probability alerts garnering a user accuracy of 98 percent over the training period and 93 percent after the training period (2000-2005) when compared against the PRODES deforestation data set, which is used to assess spatial accuracy. Implemented in Clojure and Java on the Hadoop distributed data processing platform, the algorithm is a fast, automated, and open source system for detecting forest disturbance. It is intended to be used in conjunction with higher-resolution imagery and data products that cannot be updated as quickly as MODIS-based data products. By highlighting hotspots of change, the algorithm and associated output can focus high-resolution data acquisition and aid in efforts to enforce local forest conservation efforts.

  3. Monitoring of environmental disturbance using abundance and ...

    African Journals Online (AJOL)

    ... most disturbed site. The pattern of distribution of this species revealed that Akure Forest Reserve is degenerating, a situation that could lead to loss of biodiversity if urgent conservative measures were not put in place. Keywords: Odonata; Trithemis spp; Akure Forest Reserve; diversity indices; Dragonfly; Biotic Index (DBD) ...

  4. Sleep disturbances in chronic progressive external ophthalmoplegia.

    Science.gov (United States)

    Smits, B W; Westeneng, H J; van Hal, M A; van Engelen, B G; Overeem, S

    2012-01-01

    Chronic progressive external ophthalmoplegia (CPEO) is a relatively common mitochondrial disorder. In addition to extraocular muscle weakness, various other organs can typically be affected, including laryngeal and limb muscles, cerebrum, cerebellum, and peripheral nerves. Given this multi-organ involvement, patients are likely to be prone to sleep disturbances. Here, we determined the nature, prevalence, and determinants of sleep disturbances in CPEO. We used validated questionnaires for various sleep disorders and possible determinants such as mood and anxiety, and we performed ambulant polysomnography (PSG) in 20 patients with genetically confirmed CPEO. Three quarters of patients reported nocturnal sleep dysfunction. Thirty-five percent of patients fulfilled the criteria for restless legs syndrome, 30% excessive daytime sleepiness, and 70% significant periodic limb movements. PSG recordings revealed several indicators of a disrupted sleep architecture. Obstructive sleep disordered breathing was present in only one patient. However, four patients had an increased central sleep apnea index, all of whom had a polymerase gamma-1 mutation and a SANDO phenotype (sensoric atactic neuropathy, dysarthria, ophthalmoplegia). Physical examination and questionnaire outcomes were poor predictors of PSG results. Several specific sleep disturbances are part of the phenotype of CPEO. Given that the disease is otherwise incurable, symptomatic treatment of sleep disturbances may be an important tool to improve quality of life. Therefore, patients with CPEO should be actively screened for sleep disorders, with a low threshold to perform PSG. © 2011 The Author(s). European Journal of Neurology © 2011 EFNS.

  5. Evaluation of benthic macroinvertebrate assemblage for disturbance ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 4. Evaluation of benthic macroinvertebrate assemblage for disturbance zonation in urban rivers using multivariate analysis: Implications for river management. Ram Devi Tachamo Shah Deep Narayan Shah. Volume 122 Issue 4 August 2013 pp 1125- ...

  6. Adaptive Behavior and the Psychologically Disturbed Child.

    Science.gov (United States)

    Sparrow, Sara S.; Cicchetti, Domenic V.

    1987-01-01

    Results of clinical research involving specific subtypes of psychological disorders in elementary age children are reported. Compared to controls, emotionally disturbed children manifested greatest adaptive behavior deficits in socialization and maladaptive areas of functioning, with less predictable patterns of deficit in such areas as…

  7. Solar Development on Contaminated and Disturbed Lands

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lee, Courtney [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mosey, Gail [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melius, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    Land classified as contaminated and disturbed across the United States has the potential to host developments of utility-scale solar power. This report examines the prospect of developing utility- and commercial-scale concentrated solar power (CSP) and solar photovoltaics (PV) technologies on degraded and environmentally contaminated lands. The potential for solar development on contaminated anddisturbed lands was assessed, and for the largest and highest solar resource sites, the economic impacts and feasibility were evaluated. Developing solar power on contaminated and disturbed lands can help create jobs and revitalize local and state economies, and selecting these sites over greenfield sites can potentially have permitting and environmental mitigation advantages. The U.S.Department of Energy (DOE) SunShot goals call for 632 GW of PV and 83 GW of CSP to be deployed by 2050. Conservative land-use estimates of this study (10 acres per megawatt) show that there are disturbed and environmentally contaminated lands throughout the country that could be suitable for utility-scale solar power, and, that there is sufficient land area to meet SunShot solar deployment goals. The purpose of this assessment is to improve the understanding of these sites and facilitate solar developers' selection of contaminated and disturbed sites for development.

  8. Sleep Disturbance Preceding Completed Suicide in Adolescents

    Science.gov (United States)

    Goldstein, Tina R.; Bridge, Jeffrey A.; Brent, David A.

    2008-01-01

    We examined sleep difficulties preceding death in a sample of adolescent suicide completers as compared with a matched sample of community control adolescents. Sleep disturbances were assessed in 140 adolescent suicide victims with a psychological autopsy protocol and in 131 controls with a similar semistructured psychiatric interview. Rates of…

  9. Time Perspective, Mood Disturbance, and Suicide Liberation.

    Science.gov (United States)

    Lennings, C. J.

    1994-01-01

    Assessed 238 university students and 159 high school students on temporal and personality measures. Found that temporal extension, temporal attitude, and impulsivity had comparatively little effect on suicide ideation after controlling effects of mood disturbance. However, negative temporal attitudes appeared to have significant impact on suicide…

  10. ERUPTION DISTURBANCES OF PERMANENT MOLARS - A REVIEW

    NARCIS (Netherlands)

    RAGHOEBAR, GM; BOERING, G; VISSINK, A; STEGENGA, B

    Eruption disturbances of permanent molars may become clinically and radiographically manifest as impaction, primary retention or secondary retention. This may result in clinical problems such as malocclusion and loss of neighboring teeth due to caries and periodontal disease. Which of these

  11. Switching Control for Adaptive Disturbance Attenuation

    NARCIS (Netherlands)

    Battistelli, Giorgio; Mari, Daniele; Selvi, Daniela; Tesi, Alberto; Tesi, Pietro

    The problem of adaptive disturbance attenuation is addressed in this paper using a switching control approach. A finite family of stabilizing controllers is pre-designed, with the assumption that, for any possible operating condition, at least one controller is able to achieve a prescribed level of

  12. Body representation disturbances in anorexia nervosa

    NARCIS (Netherlands)

    Keizer, A.|info:eu-repo/dai/nl/323041213

    2014-01-01

    One of the main symptoms of anorexia nervosa (AN) is a disturbed experience of body size and shape. Although patients are underweight, they experience their body as bigger than it in reality is. Previous studies were mainly conducted by (clinical) psychologists and psychiatrists, and almost

  13. Visuospatial Attention Disturbance in Duchenne Muscular Dystrophy

    Science.gov (United States)

    De Moura, Maria Clara Drummond Soares; do Valle, Luiz Eduardo Ribeiro; Resende, Maria Bernadete Dutra; Pinto, Katia Osternack

    2010-01-01

    Aim: The cognitive deficits present in the Duchenne muscular dystrophy (DMD) are not yet well characterized. Attention, considered to be the brain mechanism responsible for the selection of sensory stimuli, could be disturbed in DMD, contributing, at least partially, to the observed global cognitive deficit. The aim of this study was to…

  14. Types and Treatment of Pediatric Sleep Disturbances

    Science.gov (United States)

    Hamilton, Gloria J.

    2009-01-01

    This article provides an overview of pediatric sleep disturbances with emphases on types and treatments. Relationships between sleep disorders and comorbid conditions function to exacerbate and maintain both disorders. An estimated 20% of teenagers experience chronic partial sleep deprivation, resulting in problems with memory, attention, and…

  15. Effectiveness of carnosine on disturbed electrolytes homeostasis ...

    African Journals Online (AJOL)

    We aimed to assess the effect of well known antioxidant carnosine on disturbed plasma and intraerythrocytes electrolytes and Na+-K+-ATPase activity by cisplatin. 24 male albino Wistar rats were selected and divided into 4 groups: Group I = untreated control; Group II = cisplatin control (received cisplatin at a dose of 3 mg/ ...

  16. Pharmacotherapies for sleep disturbances in Alzheimer's disease.

    Science.gov (United States)

    McCleery, Jenny; Cohen, Daniel A; Sharpley, Ann L

    2014-03-21

    Sleep disturbances, including reduced nocturnal sleep time, sleep fragmentation, nocturnal wandering and daytime sleepiness are common clinical problems in dementia due to Alzheimer's disease (AD), and are associated with significant caregiver distress, increased healthcare costs and institutionalisation. Drug treatment is often sought to alleviate these problems, but there is significant uncertainty about the efficacy and adverse effects of the various hypnotic drugs in this vulnerable population. To assess the effects, including common adverse effects, of any drug treatment versus placebo for sleep disorders in people with Alzheimer's disease through identification and analysis of all relevant randomized controlled trials (RCTs). We searched ALOIS (www.medicine.ox.ac.uk/alois), the Cochrane Dementia and Cognitive Improvement Group's Specialized Register, on 31 March 2013 using the terms: sleep, insomnia, circadian, hypersomnia, parasomnia, somnolence, "rest-activity", sundowning. We included RCTs that compared a drug with placebo and that had the primary aim of improving sleep in people with Alzheimer's disease who had an identified sleep disturbance at baseline. Trials could also include non-pharmacological interventions as long as both drug and placebo groups had the same exposure to them. Two authors working independently extracted data on study design, risk of bias and results from the included study reports. Additional information was obtained from study authors where necessary. We used the mean difference as the measure of treatment effect and, where possible, synthesized results using a fixed-effect model. We found RCTs eligible for inclusion for three drugs: melatonin (209 participants, three studies, but only two yielded data suitable for meta-analysis), trazodone (30 participants, one study) and ramelteon (74 participants, one study, no peer-reviewed publication, very limited information available).The melatonin and trazodone studies were of people with

  17. Body image disturbance and skin bleaching.

    Science.gov (United States)

    Charles, Christopher A D; McLean, Shua-Kym

    2017-11-01

    This study looks at body image disturbance among Jamaicans who bleach their skin. The hypothesis states that there is a positive relationship between skin bleaching and body image disturbance. The study used a convenience sample of 160 participants with a skin bleaching group (n = 80) and a non-bleaching comparison group (n = 80). The instrument included demographic questions, the body image disturbance questionnaire (BIDQ), and questions about skin bleaching. The results of a t-test revealed that the skin bleaching group (M = 1.5255, SD = 0.42169) was not significantly different from the non-bleaching group (M = 1.4938, SD = 0.74217) in terms of body image disturbance, t(158) = 0.333, p = .740. The participants who bleached did not suffer from body image disturbance. Self-reports revealed that they bleached to acquire beauty, attract a partner, elude the police, and market skin bleaching products. The practice was fashionable and popular and it made some participants feel good, while others were fans of a popular musical artiste who bleached his skin. The majority of participants bleached because of the perceived personal, social, and entrepreneurial benefits of the practice and not because they suffered emotional distress, anxiety, and functional impairment because of their skin colour. However, there was some level of BID among the minority of participants who argued that they bleached because they wanted to be pretty so they were emotionally distressed about there body image and experienced functional impairment. © 2017 The British Psychological Society.

  18. [Disturbances of binocular vision in macular heterotopia].

    Science.gov (United States)

    Schroeder, B; Krzizok, T; Kaufmann, H; Kroll, P

    1999-08-01

    Tractive translocation of the macula (secondary macular heterotopia) may result in disturbance of binocular vision. The report of a case shall discuss the sensorial problems of these patients. We report of a 40-years old male who had decreased visual acuity and loss of binocular vision for several years due to episodes of uveitis with intravitreous hemorrhage and cataract formation. After bilateral vitrectomy and cataract extraction a good visual acuity was restored in both eyes. Postoperatively, the patient monocularly complained about disturbed egocentric localization (tilting of the visual environment, "past-pointing") and metamorphopsia. Binocularly he was confused by doubled vision with tilted images. Both maculae showed a tractive translocation of 15 degrees downward. Measurements of binocular alignment with the tangent screen showed an excyclotropia of 8 degrees and an exotropia of 7 degrees in all directions of gaze. Haploscopic examination with fusion images demonstrated that sensorial fusion was not possible even with perfect ocular alignment due to disturbed relative retinal localization (obligate fixation disparity). Initially, full time occlusion of the left eye was required. After improvement of symptoms occlusion therapy was slowly tapered. Within one year the patient had learned to suppress the image of his left eye and reported only minor residual visual disturbances even without occlusion of his left eye. Secondary translocation of the macula monocularly results in a disturbance of egocentric localization and in metamorphopsia. Binocularly doubled vision with tilted images and a loss of sensorial fusion are seen. With monocular vision, perceptual adapting to the aberration in egocentric localisation is possible within weeks by reallocation of the retinal meridians in the central nervous system. Binocular improvement of symptoms is limited to the learning of suppression. Improvement of binocular symptoms by adaptation of retinal correspondence does

  19. Sleep disturbance and cardiovascular risk in adolescents.

    Science.gov (United States)

    Narang, Indra; Manlhiot, Cedric; Davies-Shaw, Jolie; Gibson, Don; Chahal, Nita; Stearne, Karen; Fisher, Amanda; Dobbin, Stafford; McCrindle, Brian W

    2012-11-20

    Evidence suggests that inadequate or disturbed sleep is associated with increased cardiovascular risk in adults. There are limited data on sleep quality and associated cardiovascular risk in children. We obtained data on adolescents from the 2009/10 cycle of the Healthy Heart Schools' Program, a population-based cross-sectional study in the Niagara region of Ontario. Participants underwent measurements of cardiometabolic risk factors, including body mass index (BMI), lipid profile and blood pressure, and they completed questionnaires measuring sleeping habits and nutritional status. We assessed sleep disturbance using the sleep disturbance score derived from the Pittsburgh Sleep Quality Index. We explored associations between sleeping habits and cardiovascular risk factors. Among 4104 adolescents (51% male), the mean hours of sleep per night (± standard deviation) were 7.9 ± 1.1 on weeknights and 9.4 ± 1.6 on weekends. In total, 19% of participants reported their sleep quality as fairly bad or very bad on weeknights and 10% reported it as fairly bad or very bad on weekends. In the multivariable regression models, a higher sleep disturbance score was associated with increased odds of being at high cardiovascular risk (highest v. lowest tertile odds ratio [OR] 1.43 [95% confidence interval (CI) 1.16-1.77], p < 0.001), increased odds of hypertension (highest v. lowest tertile OR 1.44 [95% CI 1.02-2.05], p = 0.05) and increased odds of elevated non-high density lipoprotein cholesterol (highest v. lowest tertile OR 1.28 [95% CI 1.00-1.64], p = 0.05). The mean duration of sleep was not associated with these outcomes. In healthy adolescents, sleep disturbance is associated with cardiovascular risk factor abnormalities. Intervention strategies to optimize sleep hygiene early in life may be important for the prevention of cardiovascular disease.

  20. Forest disturbance interactions and successional pathways in the Southern Rocky Mountains

    Science.gov (United States)

    Lu Liang,; Hawbaker, Todd J.; Zhu, Zhiliang; Xuecao Li,; Peng Gong,

    2016-01-01

    The pine forests in the southern portion of the Rocky Mountains are a heterogeneous mosaic of disturbance and recovery. The most extensive and intensive stress and mortality are received from human activity, fire, and mountain pine beetles (MPB;Dendroctonus ponderosae). Understanding disturbance interactions and disturbance-succession pathways are crucial for adapting management strategies to mitigate their impacts and anticipate future ecosystem change. Driven by this goal, we assessed the forest disturbance and recovery history in the Southern Rocky Mountains Ecoregion using a 13-year time series of Landsat image stacks. An automated classification workflow that integrates temporal segmentation techniques and a random forest classifier was used to examine disturbance patterns. To enhance efficiency in selecting representative samples at the ecoregion scale, a new sampling strategy that takes advantage of the scene-overlap among adjacent Landsat images was designed. The segment-based assessment revealed that the overall accuracy for all 14 scenes varied from 73.6% to 92.5%, with a mean of 83.1%. A design-based inference indicated the average producer’s and user’s accuracies for MPB mortality were 85.4% and 82.5% respectively. We found that burn severity was largely unrelated to the severity of pre-fire beetle outbreaks in this region, where the severity of post-fire beetle outbreaks generally decreased in relation to burn severity. Approximately half the clear-cut and burned areas were in various stages of recovery, but the regeneration rate was much slower for MPB-disturbed sites. Pre-fire beetle outbreaks and subsequent fire produced positive compound effects on seedling reestablishment in this ecoregion. Taken together, these results emphasize that although multiple disturbances do play a role in the resilience mechanism of the serotinous lodgepole pine, the overall recovery could be slow due to the vast area of beetle mortality.

  1. Invariant Control of the Technological Plants to Compensate an Impact of Main Disturbances Preemptively

    Directory of Open Access Journals (Sweden)

    Sniders A.

    2016-06-01

    Full Text Available The paper considers a survey of the research procedures and results due to invariant control method application perspective for operation quality advancement in several technological plants (wastewater biological treatment tanks and water steam production boilers, which operate under influence of organised and random disturbances. A specified subject of research is the simulation model of the multi-link invariant control system for steam pressure stabilisation in a steam boiler by preemptive compensation of steam load and feed water flow impact on output parameter (steam pressure, developed in MATLAB/SIMULINK. Simulation block-diagram of the steam boiler invariant control system, containing closed loop PID control circuit and open loop DPC circuit, has been composed on the basis of the designed mathematical model of the system components, disturbance compensation algorithms, and operational equation of the invariant control system. Comparative response of the steam boiler, operating under influence of fluctuating disturbances, with conventional PID control and using PID-DPC control with disturbance compensation controller DPC, has been investigated. Simulation results of invariant PID – DPC control system show that output parameter of the steam boiler - pressure remains practically constant under fluctuating disturbances due to a high-speed response of DPC controller.

  2. POPULATION STRUCTURE AND SPATIAL DISTRIBUTION OF Ceratozamia mexicana BRONGN. (ZAMIACEAE IN PRESERVED AND DISTURBED ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    Andrés Rivera-Fernández

    2012-11-01

    Full Text Available Vegetal populations are affected by biotic and abiotic factors that influence the regeneration processes. The aims of this study were to know the population structure of Ceratozamia mexicana under two contrasting conditions (conserved site and disturbed site, and to determine if the sexual structure, the population density and the spatial distribution of C. mexicana are modified by effect of disturbance. Eight plots of 25 m2 within each site (conserved and disturbed were used. The structure and spatial distribution of the sites were determined. Methods included analysis of variance, spatial distribution indexes, and climatic and edaphic factors determined by conventional methods for their comparison. The conserved site showed a demographic structure of an inverted "J", while the disturbed site varied slightly with more discontinuous distribution. Population density was 0.78 individuals/m2 in the conserved site and 0.26 individuals/m2 in the disturbed site. Spatial distribution for all development stages of the plant was random, with the exception of the seedling stage, which was aggregated. Results showed that perturbation decreases the density of plants and removes reproductive individuals, which threatens the persistence of the population.

  3. The Storm Time Evolution of the Ionospheric Disturbance Plasma Drifts

    Science.gov (United States)

    Zhang, Ruilong; Liu, Libo; Le, Huijun; Chen, Yiding; Kuai, Jiawei

    2017-11-01

    In this paper, we use the C/NOFS and ROCSAT-1 satellites observations to analyze the storm time evolution of the disturbance plasma drifts in a 24 h local time scale during three magnetic storms driven by long-lasting southward IMF Bz. The disturbance plasma drifts during the three storms present some common features in the periods dominated by the disturbance dynamo. The newly formed disturbance plasma drifts are upward and westward at night, and downward and eastward during daytime. Further, the disturbance plasma drifts are gradually evolved to present significant local time shifts. The westward disturbance plasma drifts gradually migrate from nightside to dayside. Meanwhile, the dayside downward disturbance plasma drifts become enhanced and shift to later local time. The local time shifts in disturbance plasma drifts are suggested to be mainly attributed to the evolution of the disturbance winds. The strong disturbance winds arisen around midnight can constantly corotate to later local time. At dayside the westward and equatorward disturbance winds can drive the F region dynamo to produce the poleward and westward polarization electric fields (or the westward and downward disturbance drifts). The present results indicate that the disturbance winds corotated to later local time can affect the local time features of the disturbance dynamo electric field.

  4. Active Disturbance Rejection Fuzzy Controller for Roll Stabilization of Autonomous Underwater Vehicle under Wave Disturbance

    Directory of Open Access Journals (Sweden)

    Lin-Lin Wang

    2015-01-01

    Full Text Available Considering the case of autonomous underwater vehicle navigating with low speed near water surface, a new method for designing of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance under different sea conditions. Active disturbance rejection fuzzy control is applied, which is based on nonlinear motion model of autonomous underwater vehicle and the principle of zero-speed fin stabilizer. Extended state observer is used for estimation of roll motion state and unknown wave disturbance. Wave moment is counteracted by introducing compensation term into the roll control law which is founded on nonlinear feedback. Fuzzy reasoning is used for parameter adjustment of the controller online. Simulation experiments on roll motion are conducted under different sea conditions, and the results show better robustness improved by active disturbance rejection fuzzy controller of autonomous underwater vehicle navigating near water surface.

  5. Disturbance observer based pitch control of wind turbines for disturbance rejection

    Science.gov (United States)

    Yuan, Yuan; Chen, Xu; Tang, Jiong

    2016-04-01

    In this research, a disturbance observer based (DOB) control scheme is illustrated to reject the unknown low frequency disturbances to wind turbines. Specifically, we aim at maintaining the constant output power but achieving better generator speed regulation when the wind turbine is operated at time-varying and turbulent wind field. The disturbance observer combined with a filter is designed to asymptotically reject the persistent unknown time-varying disturbances. The proposed algorithm is tested in both linearized and nonlinear NREL offshore 5-MW baseline wind turbine. The application of this DOB pitch controller achieves improved power and speed regulation in Region 3 compared with a baseline gain scheduling PID collective controller both in linearized and nonlinear plant.

  6. Gastroesophageal reflux disease and vocal disturbances

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Coelho de Arruda Henry

    2011-06-01

    Full Text Available CONTEXT: Gastroesophageal reflux disease is a chronic disease in which gastroduodenal contents reflux into the esophagus. The clinical picture of gastroesophageal reflux disease is usually composed by heartburn and regurgitation (typical manifestations. Atypical manifestations (vocal disturbances and asthma may also be complaint. OBJECTIVE: To analyse the clinical, endoscopic, manometric and pHmetric aspects of patients suffering from gastroesophageal reflux disease associated with vocal disturbances. METHODS: Fifty patients with gastroesophageal reflux disease were studied, including 25 with vocal disturbances (group 1 - G1 and 25 without these symptoms (group 2 - G2. All patients were submitted to endoscopy, manometry and esophageal pHmetry (2 probes. The group 1 patients were submitted to videolaryngoscopy. RESULTS: Endoscopic findings: non-erosive reflux disease was observed in 95% of G1 patients and 88% of G2. Videolaryngoscopy: vocal fold congestion, asymmetry, nodules and polyps were observed in G1 patients. Manometric findings: pressure in the lower esophageal sphincter (mm Hg: 11.6 ± 5.2 in G1 and 14.0 ± 6.2 in G2 (P = 0.14; pressure in the upper esophageal sphincter (mm Hg: 58.4 ± 15.9 in G1 and 69.5 ± 30.7 in the controls. pHmetric findings: De Meester index: 34.0 ± 20.9 in G1 and 15.4 ± 9.4 in G2 (P<0.001; number of reflux episodes in distal probe: 43.0 ± 20.4 in G1 and 26.4 ± 17.2 in G2 (P = 0.003; percentage of time with esophageal pH value lower than 4 units (distal sensor: 9.0% ± 6.4% in G1 and 3.4% ± 2.1% in G2 (P<0.001; number of reflux episodes in proximal probe: 7.5 ± 10.9 in G1 and 5.3 ± 5.7 in G2 (P = 0.38; percentage of time with esophageal pH values lower than 4 units (Proximal probe: 1.2 ± 2.7 in G1 and 0.5 ± 0.7 in G2 (P = 0.21. CONCLUSIONS: 1 The clinical, endoscopic, and manometric findings observed in patients with vocal disturbance do not differ from those without these symptoms; 2 gastroesophageal

  7. Work-family conflict and sleep disturbance: the Malaysian working women study

    OpenAIRE

    Aazami, Sanaz; MOZAFARI, Mosayeb; Shamsuddin, Khadijah; Akmal, Syaqirah

    2015-01-01

    This study aimed at assessing effect of the four dimensions of work-family conflicts (strain and time-based work interference into family and family interference into work) on sleep disturbance in Malaysian working women. This cross-sectional study was conducted among 325 Malaysian married working women. Multiple-stage simple random sampling method was used to recruit women from public service departments of Malaysia. Self-administrated questionnaires were used to measure the study variables ...

  8. [Alienation: Differential Psychopathology of Ego-Disturbances].

    Science.gov (United States)

    Bodatsch, M; Kuhn, J

    2016-11-01

    Alienation, i. e. disorders of the inner experience of integrity, continuity, and agency, represents a feature of both psychotic and non-psychotic disorders. Thereby, ego disturbances are thought to be specific for schizophrenia. Depersonalisation, in contrast, has been reported in schizophrenia as well as a neurotic, probably distinct syndrome. The differentiation of psychotic vs. non-psychotic alienation is often all but trivial. The present paper provides an overview of the historical roots and the psychopathological conceptualizations of alienation. Clinically relevant features of psychotic alienation are highlighted. Experience of passivity, loss of authenticity and disturbances of striving and volition appear as psychotic characteristics. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Parkinson's Disease and Sleep/Wake Disturbances

    Directory of Open Access Journals (Sweden)

    Todd J. Swick

    2012-01-01

    Full Text Available Parkinson's disease (PD has traditionally been characterized by its cardinal motor symptoms of bradykinesia, rigidity, resting tremor, and postural instability. However, PD is increasingly being recognized as a multidimensional disease associated with myriad nonmotor symptoms including autonomic dysfunction, mood disorders, cognitive impairment, pain, gastrointestinal disturbance, impaired olfaction, psychosis, and sleep disorders. Sleep disturbances, which include sleep fragmentation, daytime somnolence, sleep-disordered breathing, restless legs syndrome (RLS, nightmares, and rapid eye movement (REM sleep behavior disorder (RBD, are estimated to occur in 60% to 98% of patients with PD. For years nonmotor symptoms received little attention from clinicians and researchers, but now these symptoms are known to be significant predictors of morbidity in determining quality of life, costs of disease, and rates of institutionalization. A discussion of the clinical aspects, pathophysiology, evaluation techniques, and treatment options for the sleep disorders that are encountered with PD is presented.

  10. SOME NEUROCHEMICAL DISTURBANCES IN MULTIPLE SCLEROSIS

    OpenAIRE

    Vladimir V. Markelov; Maxim V. Trushin

    2006-01-01

    ABSTRACTThe data presented in this manuscript suggest a pivotal role of the central nervous system (CNS) in the regulation of immune status. We describe here that some neurochemical disturbances may provoke development of various diseases including multiple sclerosis. Some theoretic and practical backgrounds, how to improve the multiple sclerosis sufferers and patients with other autoimmune disorders, are also given.RESUMENLos datos que presentamos en este manuscrito, sugieren un papel guia d...

  11. Abdominal Disturbances Among Dengue Fever Patients

    OpenAIRE

    Harahap, Arnold Hasahatan; Simadibrata, Marcellus; Makmun, Dadang; Hasan, Irsan

    2009-01-01

    Background: Abdominal disturbances are common symptoms found in approximately 40% of patients with dengue fever, which frequently cause significant morbidity. This study was developed as an attempt to understand the effect of plasma leakage in dengue hemorrhagic fever; particularly on ab dominal problems. Method: The study was conducted in hospitalized patients who were diagnosed with dengue fever and dengue hemorrhagic fever (based on the 1997 WHO criteria for DHF) at Fatmawati hospital, Ja...

  12. A behavioral model of infant sleep disturbance.

    OpenAIRE

    Blampied, N M; France, K G

    1993-01-01

    Chronic sleep disturbance, such as bed refusal, sleep-onset delay, and night waking with crying, affects 15% to 35% of preschool children. Biological factors, particularly arousals associated with recurrent episodes of rapid-eye-movement sleep, render infants vulnerable to repeated awakenings. Parental failure to establish appropriate stimulus control of sleep-related behaviors and parent-mediated contingencies of reinforcement for sleep-incompatible behaviors may shape and maintain infant sl...

  13. Update on endocrine disturbances in anorexia nervosa

    DEFF Research Database (Denmark)

    Støving, R K; Hangaard, J; Hagen, C

    2001-01-01

    The marked endocrine changes that occur in anorexia nervosa have aroused a great deal of interest, and over the last decade much research has been conducted in this field. The endocrine disturbances are not specific to this disorder, as they also occur in starvation states secondary to other causes...... of the large body of literature concerning endocrine aspects of anorexia nervosa with the main focus on the latest results, which provide leads for potential etiological theories....

  14. Conservation of wildlife populations: factoring in incremental disturbance.

    Science.gov (United States)

    Stewart, Abbie; Komers, Petr E

    2017-06-01

    Progressive anthropogenic disturbance can alter ecosystem organization potentially causing shifts from one stable state to another. This potential for ecosystem shifts must be considered when establishing targets and objectives for conservation. We ask whether a predator-prey system response to incremental anthropogenic disturbance might shift along a disturbance gradient and, if it does, whether any disturbance thresholds are evident for this system. Development of linear corridors in forested areas increases wolf predation effectiveness, while high density of development provides a safe-haven for their prey. If wolves limit moose population growth, then wolves and moose should respond inversely to land cover disturbance. Using general linear model analysis, we test how the rate of change in moose (Alces alces) density and wolf (Canis lupus) harvest density are influenced by the rate of change in land cover and proportion of land cover disturbed within a 300,000 km(2) area in the boreal forest of Alberta, Canada. Using logistic regression, we test how the direction of change in moose density is influenced by measures of land cover change. In response to incremental land cover disturbance, moose declines occurred where 43% of land cover was disturbed and wolf density declined. Wolves and moose appeared to respond inversely to incremental disturbance with the balance between moose decline and wolf increase shifting at about 43% of land cover disturbed. Conservation decisions require quantification of disturbance rates and their relationships to predator-prey systems because ecosystem responses to anthropogenic disturbance shift across disturbance gradients.

  15. [Disturbances of emotional prosody in schizophrenia].

    Science.gov (United States)

    Gurańska, Joanna; Gurański, Konstanty

    2013-01-01

    Disturbances in understanding and expression of emotional prosody of speech (aprosodia) belong to frequent but rarely described symptoms of schizophrenia, that negatively influence the life quality of patients. The role of prosody in the process of verbal communication is to complement and emphasize the language (linguistic prosody) and affective (emotional prosody) aspects of the spoken announcements. The authors review literature, including studies on functional brain imaging, and analyze profile and ground of the disturbances in the emotional prosody in patients with schizophrenia. Similarly to patients with damage to the right hemisphere, the speech of schizophrenia patients often is monotonous and deprived of emotional coloring, despite preserved experiencing of appropriate emotions, similarly to healthy subjects. In the acoustic speech analysis of patients with schizophrenic psychosis, reduced fundamental frequency of the utterance, clinically defined as aprosodia, was showed. It was noticed that the problems in identifying emotions concern mainly negative emotions and that bigger defects were demonstrated by men. The authors emphasize the need to recognize and include appropriate therapeutic treatments in prosody disturbances, which aim is to improve the well-being and social functioning of the patients.

  16. Preserving geomorphic data records of flood disturbances

    Science.gov (United States)

    Moody, John A.; Martin, Deborah; Meade, Robert H.

    2015-01-01

    No central database or repository is currently available in the USA to preserve long-term, spatially extensive records of fluvial geomorphic data or to provide future accessibility. Yet, because of their length and continuity these data are valuable for future research. Therefore, we built a public accessible website to preserve data records of two examples of long-term monitoring (40 and 18 years) of the fluvial geomorphic response to natural disturbances. One disturbance was ∼50-year flood on Powder River in Montana in 1978, and the second disturbance was a catastrophic flood on Spring Creek following a ∼100-year rainstorm after a wildfire in Colorado in 1996.Two critical issues arise relative to preserving fluvial geomorphic data. The first is preserving the data themselves, but the second, and just as important, is preserving information about the location of the field research sites where the data were collected so the sites can be re-located and re-surveyed in the future. The latter allows long-term datasets to be extended into the future and to provide critical background data for interpreting future landscape changes. Data were preserved on a website to allow world-wide accessibility and to upload new data to the website as they become available. We describe the architecture of the website, lessons learned in developing the website, future improvements, and recommendations on how also to preserve information about the location of field research sites.

  17. Acute Symptomatic Seizures Caused by Electrolyte Disturbances.

    Science.gov (United States)

    Nardone, Raffaele; Brigo, Francesco; Trinka, Eugen

    2016-01-01

    In this narrative review we focus on acute symptomatic seizures occurring in subjects with electrolyte disturbances. Quite surprisingly, despite its clinical relevance, this issue has received very little attention in the scientific literature. Electrolyte abnormalities are commonly encountered in clinical daily practice, and their diagnosis relies on routine laboratory findings. Acute and severe electrolyte imbalances can manifest with seizures, which may be the sole presenting symptom. Seizures are more frequently observed in patients with sodium disorders (especially hyponatremia), hypocalcemia, and hypomagnesemia. They do not entail a diagnosis of epilepsy, but are classified as acute symptomatic seizures. EEG has little specificity in differentiating between various electrolyte disturbances. The prominent EEG feature is slowing of the normal background activity, although other EEG findings, including various epileptiform abnormalities may occur. An accurate and prompt diagnosis should be established for a successful management of seizures, as rapid identification and correction of the underlying electrolyte disturbance (rather than an antiepileptic treatment) are of crucial importance in the control of seizures and prevention of permanent brain damage.

  18. Electric utility industry experience with geomagnetic disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P.R.; Rizy, D.T.; McConnell, B.W. (Oak Ridge National Lab., TN (United States)); Taylor, E.R. Jr. (ABB Power Systems, Inc., Pittsburgh, PA (United States)); Tesche, F.M.

    1991-09-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems' responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration. 49 refs.

  19. Electric Utility Industry Experience with Geomagnetic Disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P.R.

    1991-01-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as a few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems' responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration.

  20. Electric utility industry experience with geomagnetic disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, P.R.; Rizy, D.T.; McConnell, B.W. [Oak Ridge National Lab., TN (United States); Taylor, E.R. Jr. [ABB Power Systems, Inc., Pittsburgh, PA (United States); Tesche, F.M.

    1991-09-01

    A geomagnetic disturbance (GMD) by its nature occurs globally and almost simultaneously. Severe geomagnetic storms cause problems for electric power systems. The vulnerability of electric power systems to such events has apparently increased during the last 10 to 20 years because power system transmission lines have become more interconnected and have increased in length and because power systems are now operated closer to their limits than in the past. In this report, the experience of electric utilities during geomagnetic storms is examined and analyzed. Measured data, effects on power system components, and power system impacts are considered. It has been found that electric power systems are susceptible to geomagnetically induced earth-surface potential gradients as small as few (2 to 3) volts per kilometer, corresponding to a storm of K-6 intensity over an area of high earth resistivity. The causes and effects are reasonably well understood, but additional research is needed to develop a better understanding of solar-induced geomagnetic storms and the responses of power systems to these types of storms. A better understanding of geomagnetic storms and the power systems` responses to GMDs is needed so that mitigation measures can be implemented that will make power systems less susceptible to severe geomagnetic disturbances. A GMD caused by a large high-altitude nuclear detonation is similar in many ways to that of solar-induced geomagnetic storms except that a nuclear-caused disturbance would be much more intense with a far shorter duration. 49 refs.

  1. Kristian Birkeland's pioneering investigations of geomagnetic disturbances

    Directory of Open Access Journals (Sweden)

    W. J. Burke

    2010-04-01

    Full Text Available More than 100 years ago Kristian Birkeland (1967–1917 addressed questions that had vexed scientists for centuries. Why do auroras appear overhead while the Earth's magnetic field is disturbed? Are magnetic storms on Earth related to disturbances on the Sun? To answer these questions Birkeland devised terrella simulations, led coordinated campaigns in the Arctic wilderness, and then interpreted his results in the light of Maxwell's synthesis of laws governing electricity and magnetism. After analyzing thousands of magnetograms, he divided disturbances into 3 categories:

    1. Polar elementary storms are auroral-latitude disturbances now called substorms.
    2. Equatorial perturbations correspond to initial and main phases of magnetic storms.
    3. Cyclo-median perturbations reflect enhanced solar-quiet currents on the dayside.

    He published the first two-cell pattern of electric currents in Earth's upper atmosphere, nearly 30 years before the ionosphere was identified as a separate entity. Birkeland's most enduring contribution toward understanding geomagnetic disturbances flowed from his recognition that field-aligned currents must connect the upper atmosphere with generators in distant space. The existence of field-aligned currents was vigorously debated among scientists for more than 50 years. Birkeland's conjecture profoundly affects present-day understanding of auroral phenomena and global electrodynamics. In 1896, four years after Lord Kelvin rejected suggestions that matter passes between the Sun and Earth, and two years before the electron was discovered, Birkeland proposed current carriers are "electric corpuscles from the Sun" and "the auroras are formed by corpuscular rays drawn in from space, and coming from the Sun". It can be reasonably argued that the year 1896 marks the founding of space plasma physics. Many of Birkeland's insights were rooted in observations made during his terrella

  2. Rapid disturbances in Arctic permafrost regions (Invited)

    Science.gov (United States)

    Grosse, G.; Romanovsky, V. E.; Arp, C. D.; Jones, B. M.

    2013-12-01

    Permafrost thaw is often perceived as a slow process dominated by press disturbances such as gradual active layer thickening. However, various pulse disturbances such as thermokarst formation can substantially increase the rate of permafrost thaw and result in rapid landscape change on sub-decadal to decadal time scales. Other disturbances associated with permafrost thaw are even more dynamic and unfold on sub-annual timescales, such as catastrophic thermokarst lake drainage. The diversity of processes results in complex feedbacks with soil carbon pools, biogeochemical cycles, hydrology, and flora and fauna, and requires a differentiated approach when quantifying how these ecosystem componentsare affected,how vulnerablethey are to rapid change, and what regional to global scale impacts result. Here we show quantitative measurements for three examples of rapid pulse disturbances in permafrost regions as observed with remote sensing data time series: The formation of a mega thaw slump (>50 ha) in syngenetic permafrost in Siberia, the formation of new thermokarst ponds in ice-rich permafrost regions in Alaska and Siberia, and the drainage of thermokarst lakes along a gradient of permafrost extent in Western Alaska. The surprising setting and unabated growth of the mega thaw slump during the last 40 years indicates that limited information on panarctic ground ice distribution, abundance, and vulnerability remains a key gap for reliable projections of thermokarst and thermo-erosion impacts, and that the natural limits on the growth and size of thaw slumps are still poorly understood. Observed thermokarst pond formation and expansion in our study regions was closely tied to ice-rich permafrost terrain, such as syngenetic Yedoma uplands, but was also found in old drained thermokarst lake basins with epigenetic permafrost and shallow drained thermokarst lake basins whose ground ice had not been depleted by the prior lake phase. The very different substrates in which new

  3. Plant response strategies to stress and disturbance: the case of ...

    Indian Academy of Sciences (India)

    Unknown

    ulp.u-strasbg.fr). The environmental factors controlling the establishment and development of plants in different ecosystems are of two types, stress and disturbance. The effects of stress or disturbance on aquatic systems are discussed in relation.

  4. Disturbance and the dynamics of fynbos biome communities

    CSIR Research Space (South Africa)

    Cowling, RM

    1987-01-01

    Full Text Available This volume comprises invited review and research papers dealing with the effects of disturbance on the dynamics of fynbos biome communities. Since fire is the most important disturbance factor in the biome, most contributions concentrate...

  5. Clinical implications of glycometabolic disturbances in acute coronary

    NARCIS (Netherlands)

    Timmer, Jorik Rudolf

    2005-01-01

    Prevalence of glycometabolic disturbances in patients with a suspected acute coronary syndrome is high. One in three patients has signs of disturbed glucose metabolism and this condition is associated with previous or newly diagnosed coronary artery disease. Zie: Summary

  6. Disturbances in the arthroscopic view defined with video analysis

    NARCIS (Netherlands)

    Tuijthof, G. J. M.; Sierevelt, I. N.; van Dijk, C. N.

    2007-01-01

    Optimization of arthroscopic view with technological innovation. To formulate objective measures for arthroscopic image quality. This is achieved by defining uniquely interpretable descriptions of disturbances of the arthroscopic image. Disturbances in the arthroscopic view were defined focusing on

  7. WHEN THE DISTURBANCES ARE SPATIALLY CORRELATED

    African Journals Online (AJOL)

    where y is a Txl observable random vector, X is a Txk matrix of known constants with full column rank k, B is a k xl vector of unknown parameters,. :2 is a Txl random vector with expectation zero and covariance ..... Matrix Differential Calculus with Applica- tions in Statistics and Econometrics. Wiley, Chichester. Martin, D.L. ...

  8. Noise-related sleep disturbances: Does gender matter?

    Directory of Open Access Journals (Sweden)

    Martin Röösli

    2014-01-01

    Full Text Available Women sleep differently and report differently about sleep disturbances than men. However, it is unclear whether the sleep of women and men is affected differently by traffic noise exposure. We aimed to address gender specific noise effects by using objective and subjective exposure measures as well as objective and subjective outcome data. In a questionnaire survey conducted in 2008 including 733 women and 533 men from Basel, Switzerland, with follow-up 1 year later, we collected data on subjective sleep disturbances and annoyance to road traffic noise. Objective noise exposure data was obtained using validated propagation models. In a nested diary study with 119 participants, objective sleep efficiency and sleep duration was measured by means of actigraphic devices for 1551 nights. Data were analyzed using random intercept mixed-effects multilevel regression models adjusted for relevant confounding factors. Objectively measured sleep duration in highly exposed men (>55 dB was reduced by 1.5 h (95% confidence interval [CI]: 2.3-0.8 h compared with low exposed men (<30 dB. No noise effect on sleep duration was observed in women. The association of modeled noise exposure with self-reported sleep quality rating was also more pronounced in men (−0.8 unit, 95% CI: −1.4 to −0.2 than in women (−0.3 unit, 95% CI: −0.8 to 0.2. However, in highly annoyed women reduction in sleep quality and well-being rating tended to be stronger than in highly annoyed men. Our study provides some indications that noise exposure affects men′s sleep differently than women′s sleep, which may have distinct long-term health consequences.

  9. Changes in Soil Fungal Community Structure with Increasing Disturbance Frequency.

    Science.gov (United States)

    Cho, Hyunjun; Kim, Mincheol; Tripathi, Binu; Adams, Jonathan

    2017-07-01

    Although disturbance is thought to be important in many ecological processes, responses of fungal communities to soil disturbance have been little studied experimentally. We subjected a soil microcosm to physical disturbance, at a range of frequencies designed to simulate ecological disturbance events. We analyzed the fungal community structure using Illumina HiSeq sequencing of the ITS1 region. Fungal diversity was found to decline with the increasing disturbance frequencies, with no sign of the "humpback" pattern found in many studies of larger sedentary organisms. There is thus no evidence of an effect of release from competition resulting from moderate disturbance-which suggests that competition and niche overlap may not be important in limiting soil fungal diversity. Changing disturbance frequency also led to consistent differences in community composition. There were clear differences in OTU-level composition, with different disturbance treatments each having distinct fungal communities. The functional profile of fungal groups (guilds) was changed by the level of disturbance frequency. These predictable differences in community composition suggest that soil fungi can possess different niches in relation to disturbance frequency, or time since last disturbance. Fungi appear to be most abundant relative to bacteria at intermediate disturbance frequencies, on the time scale we studied here.

  10. Post-disturbance sediment recovery: Implications for watershed resilience

    Science.gov (United States)

    Sara L. Rathburn; Scott M. Shahverdian; Sandra E. Ryan

    2017-01-01

    Sediment recovery following disturbances is a measure of the time required to attain pre-disturbance sediment fluxes. Insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience.We assess post-disturbance sediment recovery in three small (1.5-100 km2), largely unaltered watersheds within the northern Colorado...

  11. Mapping forest canopy disturbance in the Upper Great Lakes, USA

    Science.gov (United States)

    James D. Garner; Mark D. Nelson; Brian G. Tavernia; Charles H. (Hobie) Perry; Ian W. Housman

    2015-01-01

    A map of forest canopy disturbance was generated for Michigan, Wisconsin, and most of Minnesota using 42 Landsat time series stacks (LTSS) and a vegetation change tracker (VCTw) algorithm. Corresponding winter imagery was used to reduce commission errors of forest disturbance by identifying areas of persistent snow cover. The resulting disturbance age map was classed...

  12. ANALYSIS OF DISTURBANCES IN LOGISTIC FLOWS IN MINING MACHINERY COMPANY

    Directory of Open Access Journals (Sweden)

    Karolina PROBIERZ

    2015-06-01

    Full Text Available Disturbances that occur in the course of transportation and storage tasks has been identified and analyzed. Disturbances occurring the most frequently in the ongoing processes of transport and storage have been selected. The article also shows possible ways of improvements of occurring disturbances. The article is of a practical nature.

  13. Evaluation of soil disturbance using fuzzy indicator approach

    Science.gov (United States)

    Soil disturbance is great problem and the evaluation of soil disturbance is very important for making decisions on agricultural and ecological management. In this manuscript, a new method for potentially evaluating soil disturbance is described. With this method the use of two indicators called “Dis...

  14. Human Dimensions of Forest Disturbance by Insects: An International Synthesis

    Science.gov (United States)

    Courtney G. Flint; Bonnie McFarlene; Martin Muller

    2008-01-01

    Ecological disturbances of forests by insects have a complex array of associated human dimensions presenting complications for natural resource decision making and relationships between stakeholders and managers. This article discusses the human context of forest disturbances by insects by reviewing four cases of bark beetle forest disturbance from British Columbia in...

  15. DisturbED: A Generalized Framework for Modeling Forest Insects and Pathogens in the Earth System

    Science.gov (United States)

    Matthes, J. H.

    2016-12-01

    Forest insects and pathogens (FIPs) are ubiquitous agents of disturbance that cause major alterations to ecosystem function and billions of dollars in damage annually. Future feedbacks between FIPs, forests, and climate change are not well understood at continental scales, due in part to the absence of the processes modulated by FIPs within Earth System Models (ESMs). To address this challenge, we developed a generalized, globally-scalable framework — DisturbED — in which mechanistic impacts of FIPs on plant physiology are scaled up to ecosystem-level processes so they can be integrated into ESMs. This framework can be used to test a suite of hypotheses concerning the effects of FIPs on forest biogeochemistry, demography, and structure in response to FIPs that vary in their host specificity, timescale and intensity of attack, and sensitivity to climatic change. Both native and invasive FIPs initiate a vast range of ecophysiological responses within individual trees, from slight stress and recovery to rapid mortality. Rather than modeling FIPs as direct agents of mortality, DisturbED couples FIP functional types with changes in individual host plant physiology to simulate resulting changes in ecosystem processes within the Ecosystem Demography (ED) model. This bottom-up modeling framework will allow for investigation of interactions among tree and FIPs physiology; demography and ecosystem dynamics; and their contingency on climatic change.

  16. Obesity and sleep disturbances: meaningful sub-typing of obesity.

    Science.gov (United States)

    Vgontzas, Alexandros N; Bixler, Edward O; Chrousos, George P; Pejovic, Slobodanka

    2008-10-01

    Obesity, excessive daytime sleepiness (EDS), and self-reported short sleep duration appear to be on the rise, while there is evidence that obesity and these sleep disorders are strongly connected. In this paper, we review data that challenge the common belief that the sleep apnoea and sleep loss, frequently associated with obesity, are the primary determinants of obesity-related objective daytime sleepiness and subjective fatigue (tiredness without increased sleep propensity). Specifically, obesity is associated with objective and subjective EDS regardless of the presence of sleep apnoea. The association between obesity and EDS was confirmed in recent studies of large random samples of the general population or clinical samples, which showed that the primary determinants of subjective EDS were depression, metabolic disturbances, i.e. obesity/diabetes and insulin resistance, and lack of physical activity, and, secondarily, sleep apnoea or sleep loss. Paradoxically, within the obese, with or without sleep apnoea, those who slept objectively better at night are sleepier (objectively) during the day than those who slept worse. The distinguishing factor between those that slept better vs. those that slept worse appears to be level of emotional stress. Furthermore, many studies reported that obesity is associated with self-reported short sleep duration; however, it appears that short sleep duration is a marker of emotional stress rather than a reflection of true sleep loss. Based on these data, we propose that obesity-related deeper sleep and objective EDS are primarily related to metabolic disturbances, whereas obesity-related poorer sleep and subjective fatigue appear to be the result of psychological distress. Furthermore, based on data from studies in normal controls and patients with sleep disorders, it appears that the interaction of the hypothalamic-pituitary-adrenal (HPA) axis and pro-inflammatory cytokines determines the level of sleep/arousal within the 24-hour

  17. Meta-analysis of sleep disturbance and suicidal thoughts and behaviors.

    Science.gov (United States)

    Pigeon, Wilfred R; Pinquart, Martin; Conner, Kenneth

    2012-09-01

    The potential association of various sleep disturbances to suicidal thoughts and behaviors is the subject of several reviews. The current meta-analysis was conducted to estimate the size of the association generally as well as between more specific relationships. Electronic databases for years 1966-2011 were searched to identify candidate studies using PubMed search terms suicide and sleep or sleep initiation/maintenance disorders or dreams or nightmares or sleep disorders/psychology or sleep disorders/epidemiology as well as Ovid search terms suicide and sleep or insomnia or nightmares. The search was supplemented by cross-referencing from identified articles and reviews. Original studies reporting both sleep disturbance and suicide outcomes were identified with 39 of 98 studies (40%) comprising 147,753 subjects selected for inclusion. Data were extracted by multiple independent observers and verified by a study author. The meta-analysis was performed using random-effects models. The size of associations was calculated for all types of sleep disturbances and suicide outcomes combined and for more specific categories including nightmares, insomnia, and insomnia subtypes and suicidal ideation, suicide attempts, and suicide. Moderator effects were evaluated. Overall, sleep disturbance was significantly associated with an increased relative risk for suicidal ideation, suicide attempt, and suicide ranging from 1.95 (95% CI, 1.41-2.69) to a relative risk of 2.95 (95% CI, 2.48-3.50) in unadjusted studies. Associations were smaller, but remained highly significant among adjusted studies. Depression did not moderate the association between sleep and suicide variables. This meta-analysis supports an association between sleep disturbance and suicidal thoughts and behaviors. Sleep disturbances in general, as well as insomnia and nightmares individually, appear to represent a risk factor for suicidal thoughts and behavior. This proposition is further bolstered by the result

  18. Does disturbance favor dispersal? An analysis of ant migration using the colony-based lattice model.

    Science.gov (United States)

    Nakamaru, Mayuko; Beppu, Yayoi; Tsuji, Kazuki

    2007-09-21

    Spatially explicit models that simulate the evolution of dispersal strategies have not considered colonial organisms. Here we develop the colony-based lattice model, in which a colony, rather than an individual, occupies each lattice site. With this model we investigate why invasive tramp ant species usually lack long-distance dispersal, despite living in frequently disturbed habitats. We assume a new trade-off between the dispersal distance and the offspring colony size in the competition between two extreme strategies: the short-distance dispersal strategy (the S strategy, simulating budding or fission), which splits a colony in half with one of the two halves moving to a neighboring site, and the long-distance dispersal strategy (the L strategy, assuming colony-founding by winged queens), which allocates a minimal resource to an offspring colony that disperses to a randomly chosen site. Mortality of a colony is assumed to depend on the size; the L strategy suffers from costs due to small initial colony size (i.e., high mortality and late colony maturity). Disturbance causes additional mortality to both types of colonies and is controlled by disturbance frequency, p, and a stochastic parameter determining the spatial autocorrelation of disturbance, q. Simulations show that the S strategy is favored under frequent but spatially small-scale disturbances (high p and low q), whereas large-scale disturbances (low p and high q) favor the L strategy. When mortality is generally high or particularly high in small colonies, the S strategy tends to be advantageous. In contrast, when colony mortality is generally low, the L strategy is favored. We discuss the importance of colony size dynamics and the trade-off between colony size and the dispersal distance in the evolution of dispersal strategies in ants and other more or less sessile organisms.

  19. Analysis of Clinical Predictors of Resolution of Sleep Disturbance Related to Frequent Nighttime Heartburn and Acid Regurgitation Symptoms in Individuals Taking Esomeprazole 20 mg or Placebo.

    Science.gov (United States)

    Johnson, David A; Le Moigne, Anne; Li, Jing; Pollack, Charles; Nagy, Peter

    2016-07-01

    Sleep disturbances related to reflux symptoms have a significant impact on the daily lives of affected individuals. These analyses identified clinical factors related to resolution of reflux-related sleep disturbance in subjects treated with esomeprazole 20 mg for 14 days. Data from the first 14 days of 2 similar randomized, double-blind studies were pooled for subjects experiencing frequent heartburn and related sleep disturbances receiving esomeprazole 20 mg (n = 357) or placebo (n = 346). A stepwise logistic regression analysis was performed with pooled and individual study data to evaluate relationships between clinical factors [treatment (esomeprazole vs. placebo), run-in sleep disturbance frequency, occurrence (yes/no) of 24-h, daytime, and nighttime heartburn (yes: ≥1 episode in 14-day treatment period)] and complete sleep disturbance resolution (no disturbances for 7 consecutive days). Absence of daytime (p = 0.0018) or nighttime (p Esomeprazole treatment was an independent significant predictor of improvement across all endpoints (p esomeprazole in subgroups with higher run-in symptom frequency. Lower run-in sleep disturbance frequency, no occurrence of daytime or nighttime heartburn during therapy, and esomeprazole treatment predicted complete reflux-related sleep disturbance resolution. The magnitude of therapeutic benefit for esomeprazole 20 mg over placebo increased with increasing baseline sleep disturbance.

  20. The active disturbance rejection control approach to stabilisation of coupled heat and ODE system subject to boundary control matched disturbance

    Science.gov (United States)

    Guo, Bao-Zhu; Liu, Jun-Jun; AL-Fhaid, A. S.; Younas, Arshad Mahmood M.; Asiri, Asim

    2015-08-01

    We consider stabilisation for a linear ordinary differential equation system with input dynamics governed by a heat equation, subject to boundary control matched disturbance. The active disturbance rejection control approach is applied to estimate, in real time, the disturbance with both constant high gain and time-varying high gain. The disturbance is cancelled in the feedback loop. The closed-loop systems with constant high gain and time-varying high gain are shown, respectively, to be practically stable and asymptotically stable.

  1. Methodology to assess quality of estimated disturbances in active disturbance rejection control structure for mechanical system.

    Science.gov (United States)

    Rosas, A David; Velazquez, V Karla; Olivares, F Luz; Camacho, T Adrian; Williams, Ivan

    2017-09-01

    A methodology to assess the quality of estimation of disturbances in mechanical systems, by state observers, in the control structure with active compensation of disturbances (ADRC) is presented. Evaluation is carried out by four performance indices that depend on the steady-state error between reference signals and output of the plant. These indices are related with the accuracy and precision of the closed loop system in the sense of norms L2 and L∞, for a set of reference signals representing the typical operating conditions of the mechanism. The effectiveness of the methodology is illustrated with the quality assessment of the estimated disturbance of five state observers to control of a simple pendulum and validated on a SCARA robot arm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  2. A remote sensing model of construction-related soil disturbance in southern Arizona

    Science.gov (United States)

    Pianalto, Frederick S.

    2010-10-01

    Construction-related soil disturbance, such as road construction, trenching, landstripping, earthmoving and blasting, is a significant source of fugitive (or airborne) dust, and fugitive dust is a potential health hazard as well as a primary cause of decreased air quality. Presented here is a remote sensing change detection method using annual Landsat Thematic Mapper (TM) images spanning 1995 and 2009 over southern Arizona to identify and characterize construction-related soil disturbance. To guide development of the remote sensing method, spatial coordinates of construction activity permit inspections performed by a local environmental quality agency to control fugitive dust are obtained and processed in a GIS. Satellite change detection methods are compared with kernel density plots of the construction activity inspection points. Band differencing in the mid-infrared spectral region (TM band 5), with a change threshold of four standard deviations above and below the change image mean, is identified as a simple and effective method to identify construction-related soil disturbance. As an accuracy assessment, buffers of 920 meter radius were generated around each dust inspection point and around an equal number of random points in a GIS. The dust inspection point buffers captured statistically significantly more of the remote sensing change pixels as compared to random point buffers (P < 0.0001 in a Mann-Whitney rank sum U-test for each year compared; 44.3% change pixel capture rate average as compared to 16.2% for random points). The remote sensing model is used to estimate location and annual surface area of construction-related soil disturbance in eastern Pima County, Arizona during the fourteen year study period. With limited preprocessing and processing requirements, the proposed model is simple to perform and may be suited for public and other environmental and health agencies to identify and assess fugitive dust sources and inputs to total ambient dust

  3. Neurological and Sleep Disturbances in Bronchiectasis

    Directory of Open Access Journals (Sweden)

    Chun Seng Phua

    2017-11-01

    Full Text Available Bronchiectasis unrelated to cystic fibrosis is a chronic lung disease that is increasingly recognised worldwide. While other common chronic lung conditions such as chronic obstructive lung disease have been associated with cardiovascular disease, there is a paucity of data on the relationship between bronchiectasis and cardiovascular risks such as stroke and sleep disturbance. Furthermore, it is unclear whether other neuropsychological aspects are affected, such as cognition, cerebral infection, anxiety and depression. In this review, we aim to highlight neurological and sleep issues in relation to bronchiectasis and their importance to patient care.

  4. Precise Disturbance Modeling for Improvement of Positioning Performance

    Science.gov (United States)

    Yamamoto, Masafumi; Iwasaki, Makoto; Ito, Kazuaki; Matsui, Nobuyuki

    This paper presents a modeling methodology for unknown disturbances in mechatronics systems, based on a disturbance estimation using an iterative learning process. In the disturbance modeling, the nonlinear friction is especially handled as the disturbance in mechanisms, which mainly deteriorates the trajectory control performance. The friction can be mathematically modeled by using the learned estimation data, as a function of displacement, velocity, acceleration, and jerk of the actuator. This model has a distinguished feature that the friction compensation can be achieved with a generalization capability for different conditions. The proposed positioning control approach with the disturbance modeling and compensation has been verified by experiments using a table drive system on machine stand.

  5. Changing disturbance regimes, ecological memory, and forest resilience

    Science.gov (United States)

    Johnstone, Jill F.; Allen, Craig D.; Franklin, Jerry F.; Frelich, Lee E.; Harvey, Brian J.; Higuera, Philip E.; Mack, Michelle C.; Meentemeyer, Ross K.; Metz, Margaret R.; Perry, George LW; Schoennagel, Tania; Turner, Monica G.

    2016-01-01

    Ecological memory is central to how ecosystems respond to disturbance and is maintained by two types of legacies – information and material. Species life-history traits represent an adaptive response to disturbance and are an information legacy; in contrast, the abiotic and biotic structures (such as seeds or nutrients) produced by single disturbance events are material legacies. Disturbance characteristics that support or maintain these legacies enhance ecological resilience and maintain a “safe operating space” for ecosystem recovery. However, legacies can be lost or diminished as disturbance regimes and environmental conditions change, generating a “resilience debt” that manifests only after the system is disturbed. Strong effects of ecological memory on post-disturbance dynamics imply that contingencies (effects that cannot be predicted with certainty) of individual disturbances, interactions among disturbances, and climate variability combine to affect ecosystem resilience. We illustrate these concepts and introduce a novel ecosystem resilience framework with examples of forest disturbances, primarily from North America. Identifying legacies that support resilience in a particular ecosystem can help scientists and resource managers anticipate when disturbances may trigger abrupt shifts in forest ecosystems, and when forests are likely to be resilient.

  6. Basic self-disturbance, neurocognition and metacognition

    DEFF Research Database (Denmark)

    Koren, Dan; Scheyer, Ravit; Reznik, Noa

    2017-01-01

    AIM: The goal of this pilot study was to assess the association between basic self-disturbance (SD) and deficits in neurocognitive and metacognitive functioning among help-seeking adolescents with and without attenuated psychosis syndrome (APS). METHODS: Sixty-one non-psychotic, help-seeking adol......AIM: The goal of this pilot study was to assess the association between basic self-disturbance (SD) and deficits in neurocognitive and metacognitive functioning among help-seeking adolescents with and without attenuated psychosis syndrome (APS). METHODS: Sixty-one non-psychotic, help......-seeking adolescents (age 13-18) were assessed with the examination of anomalous self-experience, the structured interview for prodromal syndromes and a new metacognitive approach to neurocognitive assessment applied to two non-social (executive functions and verbal memory) and two social (theory of mind and emotion......: As hypothesized, metacognitive monitoring and control had a significant contribution to the prediction of SD over and above neurocognitive functioning and attenuated psychotic symptoms. However, the direction of this association was positive rather than negative. Also, inconsistent with or hypothesis...

  7. Cortical activation following a balance disturbance.

    Science.gov (United States)

    Quant, S; Adkin, A L; Staines, W R; McIlroy, W E

    2004-04-01

    Although recent work suggests that cortical processing can be involved in the control of balance responses, the central mechanisms involved in these reactions remain unclear. We presently investigated the characteristics of scalp-recorded perturbation-evoked responses (PERs) following a balance disturbance. Eight young adults stabilized an inverted pendulum using their ankle musculature while seated. When perturbations were applied to the pendulum, subjects were instructed to return (active condition) or not return (passive condition) the pendulum to its original stable position. Primary measures included peak latency and amplitude of early PERs (the first negative peak between 100 and 150 ms, N1), amplitude of late PERs (between 200 and 400 ms) and onset and initial amplitude of ankle muscle responses. Based on the timing of PERs, we hypothesized that N1 would represent sensory processing of the balance disturbance and that late PERs would be linked to the sensorimotor processing of balance corrections. Our results revealed that N1 was maximal over frontal-central electrode sites (FCz and Cz). Average N1 measures at FCz, Cz, and CPz were comparable between active and passive tasks ( p>0.05). In contrast, the amplitude of late PERs at Cz was less positive for the active condition than for the passive ( psensory representation of early PERs. Differences in late PERs may represent sensorimotor processing related to the execution of balance responses.

  8. Sleep patterns and sleep disturbances across pregnancy.

    Science.gov (United States)

    Mindell, Jodi A; Cook, Rae Ann; Nikolovski, Janeta

    2015-04-01

    This study sought to characterize sleep patterns and sleep problems in a large sample of women across all months of pregnancy. A total of 2427 women completed an Internet-based survey that included the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, vitality scale of the Short Form 36 Health Survey (SF-36), Insomnia Severity Index (ISI), Berlin questionnaire, International Restless Legs Syndrome (IRLS) question set, and a short version of the Pregnancy Symptoms Inventory (PSI). Across all months of pregnancy, women experienced poor sleep quality (76%), insufficient nighttime sleep (38%), and significant daytime sleepiness (49%). All women reported frequent nighttime awakenings (100%), and most women took daytime naps (78%). Symptoms of insomnia (57%), sleep-disordered breathing (19%), and restless legs syndrome (24%) were commonly endorsed, with no difference across the month of pregnancy for insomnia, sleep-disorder breathing, daytime sleepiness, or fatigue. In addition, high rates of pregnancy-related symptoms were found to disturb sleep, especially frequent urination (83%) and difficulty finding a comfortable sleep position (79%). Women experience significant sleep disruption, inadequate sleep, and high rates of symptoms of sleep disorder throughout pregnancy. These results suggest that all women should be screened and treated for sleep disturbances throughout pregnancy, especially given the impact of inadequate sleep and sleep disorders on fetal, pregnancy, and postpartum outcomes. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Relativistic electrons produced by foreshock disturbances

    CERN Document Server

    Wilson, L B; Turner, D L; Osmane, A; Caprioli, D; Angelopoulos, V

    2016-01-01

    Foreshock disturbances -- large-scale (~1000 km to >30,000 km), transient (~5-10 per day - lasting ~10s of seconds to several minutes) structures [1,2] - generated by suprathermal (>100 eV to 100s of keV) ions [3,4] arise upstream of Earth's bow shock formed by the solar wind colliding with the Earth's magnetosphere. They have recently been found to accelerate ions to energies of several keV [5,6]. Although electrons in Saturn's high Mach number (M > 40) bow shock can be accelerated to relativistic energies (nearly 1000 keV) [7], it has hitherto been thought impossible to accelerate electrons at the much weaker (M < 20) Earth's bow shock beyond a few 10s of keV [8]. Here we report observations of electrons energized by foreshock disturbances to energies up to at least ~300 keV. Although such energetic electrons have been previously reported, their presence has been attributed to escaping magnetospheric particles [9,10] or solar events [11]. These relativistic electrons are not associated with any solar act...

  10. Acupuncture to Reduce Sleep Disturbances in Perimenopausal and Postmenopausal Women: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Chiu, Hsiao-Yean; Hsieh, Yu-Jung; Tsai, Pei-Shan

    2016-03-01

    To examine the association of acupuncture with sleep disturbances and serum sex hormone levels in perimenopausal and postmenopausal women and whether there are associated changes in sex hormone levels. We systematically searched electronic databases (EMBASE, PubMed, PsycINFO, CINAHL, ClinicalTrials.gov, Wanfang Data Chinese Database, and China Knowledge Resource Integrated Database) and the reference lists of the identified studies. Randomized controlled trials that examined the effects of acupuncture on sleep disturbances in perimenopausal and postmenopausal women were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement was followed. We identified 31 randomized controlled trials with 34 effect sizes involving a total of 2,433 participants. Acupuncture is associated with a significant reduction in the likelihood of sleep disturbances (odds ratio [OR] 0.21, 95% confidence interval [CI] 0.14-0.31), a significant increase in the secretion of serum estradiol (pooled difference in means 7.56 pg/mL, 95% CI 4.03-11.08), and reduction in the secretion of serum follicle-stimulating hormone (-6.75 milli-international units/mL, 95% CI -12.16 to -1.34) and luteinizing hormone (-2.71 milli-international units/mL, 95% CI -4.22 to -1.20). Studies with a large effect size of acupuncture-associated changes in serum estradiol had a significantly lower odds of sleep disturbances than did those with a small-to-moderate effect sizes (ORs 0.07 and 0.36, P=.02). Acupuncture is associated with a significant reduction in sleep disturbances in women experiencing menopause-related sleep disturbances. Our findings suggest that acupuncture should be adopted as part of a multimodal approach for improving sleep disturbances in perimenopausal and postmenopausal women.

  11. Stochastic stationary response of a variable-mass system with mass disturbance described by Poisson white noise

    Science.gov (United States)

    Qiao, Yan; Xu, Wei; Jia, Wantao; Han, Qun

    2017-05-01

    Variable-mass systems have received widespread attention and show prominent significance with the explosive development of micro- and nanotechnologies, so there is a growing need to study the influences of mass disturbances on systems. This paper is devoted to investigating the stochastic response of a variable-mass system subject to weakly random excitation, in which the mass disturbance is modeled as a Poisson white noise. Firstly, the original system is approximately replaced by the associated conservative system with small disturbance based on the Taylor expansion technique. Then the stationary response of the approximate system is obtained by applying the stochastic averaging method. At last, a representative variable-mass oscillator is worked out to illustrate the effectiveness of the analytical solution by comparing with Monte Carlo simulation. The relative change of mean-square displacement is used to measure the influences of mass disturbance on system responses. Results reveal that the stochastic responses are more sensitive to mass disturbance for some system parameters. It is also found that the influences of Poisson white noise as the mass disturbance on system responses are significantly different from that of Gaussian white noise of the same intensity.

  12. Disturbance and Dissonance - Community University Collaboration in Diagnosis and Treatment of Disturbances.

    Science.gov (United States)

    Fish, Caroline C.; And Others

    In 1967 the Head Start Evaluation and Research Center at Boston University initiated a project aimed at devising and assessing new clinical approaches to primary and secondary prevention of emotional disturbance in preschool children. The growth of "Black Power" plus a year of experience resulted in the making of several changes in the…

  13. Disturbance observer-based L1 robust tracking control for hypersonic vehicles with T-S disturbance modeling

    Directory of Open Access Journals (Sweden)

    Yang Yi

    2016-11-01

    Full Text Available This article concerns a disturbance observer-based L1 robust anti-disturbance tracking algorithm for the longitudinal models of hypersonic flight vehicles with different kinds of unknown disturbances. On one hand, by applying T-S fuzzy models to represent those modeled disturbances, a disturbance observer relying on T-S disturbance models can be constructed to track the dynamics of exogenous disturbances. On the other hand, L1 index is introduced to analyze the attenuation performance of disturbance for those unmodeled disturbances. By utilizing the existing convex optimization algorithm, a disturbance observer-based proportional-integral-controlled input is proposed such that the stability of hypersonic flight vehicles can be ensured and the tracking error for velocity and altitude in hypersonic flight vehicle models can converge to equilibrium point. Furthermore, the satisfactory disturbance rejection and attenuation with L1 index can be obtained simultaneously. Simulation results on hypersonic flight vehicle models can reflect the feasibility and effectiveness of the proposed control algorithm.

  14. Perennial non-infectious rhinitis--an independent risk factor for sleep disturbances in Asthma.

    Science.gov (United States)

    Hellgren, Johan; Omenaas, Ernst; Gíslason, Thórarinn; Jögi, Rain; Franklin, Karl A; Lindberg, Eva; Janson, Christer; Torén, Kjell

    2007-05-01

    To evaluate if perennial non-infectious rhinitis is associated with sleep disturbances in asthma. This is a questionnaire based study in a random population sample from Denmark, Estonia, Iceland, Norway and Sweden aged 30-54yr. A total of 1127 individuals reporting asthma from an original random population sample of 16,191 were analysed regarding their quality of sleep in relation to perennial non-infectious rhinitis. Perennial non-infectious rhinitis was defined as having nasal symptoms such as nasal blockage and secretion in the absence of common cold, always. Asthma was defined as both ever having had asthma and having physician diagnosed asthma. Odds ratios (OR) for difficulties inducing sleep, difficulties maintaining sleep, early morning awakenings and daytime sleepiness were calculated in a multiple logistic regression controlling for other risk factors for sleep disturbances such as snoring, wheeze, obesity and smoking. The response rate was 74%. A total of 189 (17%) of the subjects with asthma reported perennial non-infectious rhinitis. Perennial non-infectious rhinitis was associated with an increased OR for difficulties maintaining sleep (1.6 (95% confidence interval (CI) 1.1-2.3)), early morning awakenings (1.5 (95% CI 1.1-2.2)) and daytime sleepiness (1.8 (95% CI 1.2-2.9)). The result show that perennial non-infectious rhinitis is an independant risk factor for sleep disturbances in asthma.

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

    Science.gov (United States)

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

    2014-01-01

    Study Objectives: To compare pregabalin versus placebo and pramipexole for reducing restless legs syndrome (RLS)-related sleep disturbance. Design: Randomized, double-blinded, crossover trial. Setting: Twenty-three US sleep centers. Participants: Eighty-five individuals with moderate to severe idiopathic RLS and associated sleep disturbance. Interventions: Participants were randomized across 6 treatment sequences comprising three 4-week periods on pregabalin 300 mg/day (n = 75), pramipexole 0.5 mg/day (n = 76), or placebo (n = 73). Measurements and Results: Polysomnography was conducted over 2 nights at the end of each period. Primary (wake after sleep onset [WASO], pregabalin vs placebo) and key secondary endpoints were analyzed for statistical significance, with descriptive statistics for other endpoints. Pregabalin improved sleep maintenance, demonstrated by reductions in WASO (-27.1 min vs placebo [P Pregabalin also increased slow wave sleep duration (20.9 min vs placebo; 32.1 vs pramipexole [P pregabalin was similar to pramipexole and greater than placebo (-3.7 PLMA/h [P pregabalin compared with placebo and pramipexole. Effects of pregabalin on periodic limb movement arousal index were comparable to pramipexole. Trial Registration: ClinicalTrials.gov identifier, NCT00991276; http://clinicaltrials.gov/show/NCT00991276 Citation: Garcia-Borreguero D; Patrick J; DuBrava S; Becker PM; Lankford A; Chen C; Miceli J; Knapp L; Allen RP. Pregabalin versus pramipexole: effects on sleep disturbance in restless legs syndrome. SLEEP 2014;37(4):635-643. PMID:24899755

  16. Disturbed temporal dynamics of brain synchronization in vision loss.

    Science.gov (United States)

    Bola, Michał; Gall, Carolin; Sabel, Bernhard A

    2015-06-01

    Damage along the visual pathway prevents bottom-up visual input from reaching further processing stages and consequently leads to loss of vision. But perception is not a simple bottom-up process - rather it emerges from activity of widespread cortical networks which coordinate visual processing in space and time. Here we set out to study how vision loss affects activity of brain visual networks and how networks' activity is related to perception. Specifically, we focused on studying temporal patterns of brain activity. To this end, resting-state eyes-closed EEG was recorded from partially blind patients suffering from chronic retina and/or optic-nerve damage (n = 19) and healthy controls (n = 13). Amplitude (power) of oscillatory activity and phase locking value (PLV) were used as measures of local and distant synchronization, respectively. Synchronization time series were created for the low- (7-9 Hz) and high-alpha band (11-13 Hz) and analyzed with three measures of temporal patterns: (i) length of synchronized-/desynchronized-periods, (ii) Higuchi Fractal Dimension (HFD), and (iii) Detrended Fluctuation Analysis (DFA). We revealed that patients exhibit less complex, more random and noise-like temporal dynamics of high-alpha band activity. More random temporal patterns were associated with worse performance in static (r = -.54, p = .017) and kinetic perimetry (r = .47, p = .041). We conclude that disturbed temporal patterns of neural synchronization in vision loss patients indicate disrupted communication within brain visual networks caused by prolonged deafferentation. We propose that because the state of brain networks is essential for normal perception, impaired brain synchronization in patients with vision loss might aggravate the functional consequences of reduced visual input. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. LEDAPS: A North American Disturbance Record from Landsat Imagery

    Science.gov (United States)

    Masek, J. G.; Hall, F.; Wolfe, R.; Cohen, W.

    2004-12-01

    The disturbance regime of forests exerts a strong control on North American terrestrial carbon dynamics. Disturbance events themselves (fire, harvest, insect damage) emit carbon directly to the atmosphere; regrowth following disturbance tends to sequester carbon from the atmosphere. In general, the spatio-temporal patterns of disturbance control the age structure and successional patterns of forests, and thus influence net ecosystem productivity on a regional basis. The Landsat remote sensing program has collected high-resolution (30-80 meter resolution) imagery since 1972, and provides an excellent tool for assessing recent disturbance patterns. To date, however, this archive has not been comprehensively analyzed for such information. To remedy this, the LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project at NASA GSFC is processing decadal Landsat imagery centered on 1975, 1990, and 2000 epochs to map forest disturbance rates and patterns across North America. Landsat imagery is calibrated and atmospherically corrected to surface reflectance using the 6S radiative transfer model. Disturbance patterns are extracted in two phases. First, a simple Disturbance Index (S. Healey, personal communication) is used to map the location of significant biomass loss following a `tasseled cap' radiometric transformation. Second, we are experimenting with the integration of canopy reflectance models to relate pixel radiometry directly to stand attributes (canopy cover, forest type) to better characterize regrowth state. Initial "Beta" products have been released and feedback from the land science community is invited. This presentation will give an overview of the LEDAPS project, and present initial results from reflectance processing and disturbance mapping.

  18. Prevalence and correlates of sleep disturbance and depressive symptoms among Chinese adolescents: a cross-sectional survey study.

    Science.gov (United States)

    Guo, Lan; Deng, Jianxiong; He, Yuan; Deng, Xueqing; Huang, Jinghui; Huang, Guoliang; Gao, Xue; Lu, Ciyong

    2014-07-29

    To investigate the prevalence and the correlates of sleep disturbance and depressive symptoms among Chinese adolescents and to examine the association between the two problems. Cross-sectional survey. A total of 3186 school students in grades 7-12 were sampled from the schools in Guangdong. A stratified-cluster random-sampling strategy was used to select the schools. A self-administered questionnaire was used. The Pittsburgh Sleep Quality index (PSQI) was used to assess the occurrence of sleep disturbance, and the Center for Epidemiology Scale for Depression (CES-D) was used to identify whether individuals had depressive symptoms. The mean PSQI global score was 8.7 (±2.4) points, and 39.6% of the total sample had sleep disturbance. The mean CES-D score of students was 15.2 (±9.4) points, and 6.4% of the students had depressive symptoms. Additionally, girls and older adolescents were more likely to suffer from sleep disturbance, and the students who had depressive symptoms were 2.47 (95% CI 1.61 to 3.79) times more likely to suffer from sleep disturbance. Factors that were correlated with sleep disturbance and depressive symptoms were having a poor relationship with teachers, feeling lonely, suicide ideation and having run away from home. Sleep disturbance was determined to be more prevalent among Chinese adolescents with depressive symptoms. Sleep disturbance and depressive symptoms were associated with each other, while school factors, family factors and psychosocial adjustment were comprehensively correlated with both. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Geophysical field disturbances and quantum mechanics

    Science.gov (United States)

    Kuznetsov, Vladimir

    2017-10-01

    Quantum processes impact into physics of geophysical field disturbances is discussed here in examples of phenomena such as an earthquake with processes preceding and accompanying it, volcanoes eruptions and diamond exploding pipes. Physics of shock waves generation in ionosphere and atmosphere, mechanism of atmosphere phenomena in supercooled clouds recorded by a stormglass is considered. The report treats of physics of ball and dark lightning, of generating in atmosphere the high-energy particles involved in sprites occurrence, and so on. Geophysical phenomena considered here have no clear and consistent interpretation in the context of classical physics. We attempt to involve the recent achievements of quantum physics namely the quantum entanglement between elementary particles implicated in considered phenomena.

  20. Disturbances of cellular immunity in rheumatic fever.

    Science.gov (United States)

    Georgescu, C; Gheorghiu, M

    1976-01-01

    The alteration of cellular reactivity was investigated in 20 patients with rheumatic fever at the first rheumatic attack or in relapse with confirmed heart damage. The results obtained by studying in parallel ESR, the ASLO titer, IDR to streptococci and the degree of leukocyte migration inhibition proved that the onset of rheumatic attack was preceded by a deep disturbance of the cellular immunity. The migration inhibition values were between 50 and 60% (as compared with 10% in the normal controls) in over 85% of the patients investigated. It is emphasized that the selection of cases of streptococcal angina should be made very carefully and that sometimes it is necessary to use a more specific method for the detection of rheumatic fever in its preclinical stage.

  1. Disturbances in equilibrium function after major earthquake

    Science.gov (United States)

    Honma, Motoyasu; Endo, Nobutaka; Osada, Yoshihisa; Kim, Yoshiharu; Kuriyama, Kenichi

    2012-10-01

    Major earthquakes were followed by a large number of aftershocks and significant outbreaks of dizziness occurred over a large area. However it is unclear why major earthquake causes dizziness. We conducted an intergroup trial on equilibrium dysfunction and psychological states associated with equilibrium dysfunction in individuals exposed to repetitive aftershocks versus those who were rarely exposed. Greater equilibrium dysfunction was observed in the aftershock-exposed group under conditions without visual compensation. Equilibrium dysfunction in the aftershock-exposed group appears to have arisen from disturbance of the inner ear, as well as individual vulnerability to state anxiety enhanced by repetitive exposure to aftershocks. We indicate potential effects of autonomic stress on equilibrium function after major earthquake. Our findings may contribute to risk management of psychological and physical health after major earthquakes with aftershocks, and allow development of a new empirical approach to disaster care after such events.

  2. Associations of sleep disturbance with ADHD

    DEFF Research Database (Denmark)

    Hvolby, A.

    2015-01-01

    , difficulty with morning awakenings, sleep onset difficulties, sleep-disordered breathing, night awakenings and daytime sleepiness in subjective studies. ADHD is also frequently coincident with sleep disorders (obstructive sleep apnea, peripheral limb movement disorder, restless legs syndrome and circadian...... with ADHD with typically developing controls is most concordant for associations of ADHD with: hypopnea/apnea and peripheral limb movements in sleep or nocturnal motricity in polysomnographic studies; increased sleep onset latency and shorter sleep time in actigraphic studies; and bedtime resistance......Attention-deficit/hyperactivity disorder (ADHD) is commonly associated with disordered or disturbed sleep. The relationships of ADHD with sleep problems, psychiatric comorbidities and medications are complex and multidirectional. Evidence from published studies comparing sleep in individuals...

  3. [Ecotourism disturbances to non-human primates].

    Science.gov (United States)

    Fan, Peng-Lai; Xiang, Zuo-Fu

    2013-02-01

    In tandem with economic growth and rising living conditions, ecotourism has increasingly gained popularity among the Chinese public. Non-human primates, as charismatic animals and the closest relatives of human beings, have shown a strong affinity in attracting the general public and raising money, and for that reason a variety of monkey parks, valleys, and islands are becoming increasingly popular in China. Though successful in raising a substantial sum of money for the managing agency of a nature reserve, there may be negative impacts on monkey groups used in ecotourism. Here, to establish effective guards for non-human primates involved in ecotourism, we present a review on tourism disturbance and summarize the negative impacts on behavioral patterns, reproduction, and health condition of animals.

  4. Estimation of Wave Disturbance in Harbours

    DEFF Research Database (Denmark)

    Helm-Petersen, Jacob

    been presented for the analysis of reflected wave fields in 2D and 3D. The Bayesian Directional Wave Spectrum Estimation Method has been applied throughout the study. Reflection characteristics have been investigated by use of physical models for three types of coastal structures with vertical fronts......The motivation for the present study has been to improve the reliability in using numerical wave propagation models as a tool for estimating wave disturbance in harbours. Attention has been directed towards the importance of the modelling of reflection in the applied mild-slope model. Methods have....... The analyses include mainly directional waves. Analysis of field measurements has also taken place. Simulations with a mild-slope model have been carried out with individual structures and a complete harbour. The analyses clarify to a wide extent the behaviour of the sponge layers applied in the model...

  5. Amines as occupational hazards for visual disturbance.

    Science.gov (United States)

    Jang, Jae-Kil

    2016-01-01

    Various amines, such as triethylamine and N,N-dimethylethylamine, have been reported to cause glaucopsia in workers employed in epoxy, foundry, and polyurethane foam industries. This symptom has been related to corneal edema and vesicular collection of fluid within the corneal subepithelial cells. Exposure to amine vapors for 30 min to several hours leads to blurring of vision, a blue-grey appearance of objects, and halos around lights, that are probably reversible. Concentration-effect relationships have been established. The visual disturbance is considered a nuisance, as it could cause onsite accidents, impair work efficiency, and create difficulties in driving back home. Occupational exposure limits have been established for some amines, but there is shortage of criteria. Volatility factors, such as vapor pressure, should be considered in industrial settings to prevent human ocular risks, while trying to reduce levels of hazardous amines in the atmosphere.

  6. SOME NEUROCHEMICAL DISTURBANCES IN MULTIPLE SCLEROSIS

    Directory of Open Access Journals (Sweden)

    Vladimir V. Markelov

    2006-04-01

    Full Text Available ABSTRACTThe data presented in this manuscript suggest a pivotal role of the central nervous system (CNS in the regulation of immune status. We describe here that some neurochemical disturbances may provoke development of various diseases including multiple sclerosis. Some theoretic and practical backgrounds, how to improve the multiple sclerosis sufferers and patients with other autoimmune disorders, are also given.RESUMENLos datos que presentamos en este manuscrito, sugieren un papel guia del sistema nervioso central (SNC en la regulación del estado inmune. Describimos aquí que varias alteraciones neuroquímicas pueden provocar el desarrollo de varias enfermedades, incluyendo esclerosis múltiple. También se comenta acerca del trasfondo teórico y práctico, y cómo mejorar a víctimas y pacientes con esclerosis múltiple y otras alteraciones autoinmunes.

  7. Disturbing pasts: Memories, controversies and creativity

    Directory of Open Access Journals (Sweden)

    Leon Wainwright

    2014-10-01

    Full Text Available This themed issue of the Open Arts Journal, ‘Disturbing pasts: Memories, controversies and creativity’, brings together a range of artists, curators, policy-makers and academics from around the world, who explore creative engagements with controversial and traumatic pasts in art practice, curating and museums. The material is presented in three parts: ‘Difficult Pasts and Public Space’ (writings on historical issues and museums, ‘Visual Investigations’ (artists’ statements and criticism, and ‘Collaborations’ (visual analysis and artist-scholar pairings of writings and original artworks. This collection was developed through a two-year international research project led by Leon Wainwright, which involved three consortia of researchers from universities throughout Europe, and focused on a major public event at the Museum of Ethnology Vienna/ Weltmuseum, Wien (November 2011. The project is funded by HERA (Humanities in the European Research Area, the European Science Foundation.

  8. Surface disturbances: their role in accelerating desertification

    Science.gov (United States)

    Belnap, Jayne

    1995-01-01

    Maintaining soil stability and normal water and nutrient cycles in desert systems is critical to avoiding desertification. These particular ecosystem processes are threatened by trampling of livestock and people, and by off-road vehicle use. Soil compaction and disruption of cryptobiotic soil surfaces (composed of cyanobacteria, lichens, and mosses) can result in decreased water availability to vascular plants through decreased water infiltration and increased albedo with possible decreased precipitation. Surface disturbance may also cause accelerated soil loss through wind and water erosion and decreased diversity and abundance of soil biota. In addition, nutrient cycles can be altered through lowered nitrogen and carbon inputs and slowed decomposition of soil organic matter, resulting in lower nutrient levels in associated vascular plants. Some cold desert systems may be especially susceptible to these disruptions due to the paucity of surface-rooting vascular plants for soil stabilization, fewer nitrogen-fixing higher plants, and lower soil temperatures, which slow nutrient cycles. Desert soils may recover slowly from surface disturbances, resulting in increased vulnerability to desertification. Recovery from compaction and decreased soil stability is estimated to take several hundred years. Re-establishment rates for soil bacterial and fungal populations are not known. The nitrogen fixation capability of soil requires at least 50 years to recover. Recovery of crusts can be hampered by large amounts of moving sediment, and re-establishment can be extremely difficult in some areas. Given the sensitivity of these resources and slow recovery times, desertification threatens million of hectares of semiarid lands in the United States.

  9. Control of variable speed variable pitch wind turbine based on a disturbance observer

    Science.gov (United States)

    Ren, Haijun; Lei, Xin

    2017-11-01

    In this paper, a novel sliding mode controller based on disturbance observer (DOB) to optimize the efficiency of variable speed variable pitch (VSVP) wind turbine is developed and analyzed. Due to the highly nonlinearity of the VSVP system, the model is linearly processed to obtain the state space model of the system. Then, a conventional sliding mode controller is designed and a DOB is added to estimate wind speed. The proposed control strategy can successfully deal with the random nature of wind speed, the nonlinearity of VSVP system, the uncertainty of parameters and external disturbance. Via adding the observer to the sliding mode controller, it can greatly reduce the chattering produced by the sliding mode switching gain. The simulation results show that the proposed control system has the effectiveness and robustness.

  10. Random thoughts

    Science.gov (United States)

    ajansen; kwhitefoot; panteltje1; edprochak; sudhakar, the

    2014-07-01

    In reply to the physicsworld.com news story “How to make a quantum random-number generator from a mobile phone” (16 May, http://ow.ly/xFiYc, see also p5), which describes a way of delivering random numbers by counting the number of photons that impinge on each of the individual pixels in the camera of a Nokia N9 smartphone.

  11. Reconstructing disturbances and their biogeochemical consequences over multiple timescales

    Science.gov (United States)

    McLauchlan, Kendra K.; Higuera, Philip E.; Gavin, Daniel G.; Perakis, Steven S.; Mack, Michelle C.; Alexander, Heather; Battles, John; Biondi, Franco; Buma, Brian; Colombaroli, Daniele; Enders, Sara K.; Engstrom, Daniel R.; Hu, Feng Sheng; Marlon, Jennifer R.; Marshall, John; McGlone, Matt; Morris, Jesse L.; Nave, Lucas E.; Shuman, Bryan; Smithwick, Erica A.H.; Urrego, Dunia H.; Wardle, David A.; Williams, Christopher J.; Williams, Joseph J.

    2014-01-01

    Ongoing changes in disturbance regimes are predicted to cause acute changes in ecosystem structure and function in the coming decades, but many aspects of these predictions are uncertain. A key challenge is to improve the predictability of postdisturbance biogeochemical trajectories at the ecosystem level. Ecosystem ecologists and paleoecologists have generated complementary data sets about disturbance (type, severity, frequency) and ecosystem response (net primary productivity, nutrient cycling) spanning decadal to millennial timescales. Here, we take the first steps toward a full integration of these data sets by reviewing how disturbances are reconstructed using dendrochronological and sedimentary archives and by summarizing the conceptual frameworks for carbon, nitrogen, and hydrologic responses to disturbances. Key research priorities include further development of paleoecological techniques that reconstruct both disturbances and terrestrial ecosystem dynamics. In addition, mechanistic detail from disturbance experiments, long-term observations, and chronosequences can help increase the understanding of ecosystem resilience.

  12. United States Forest Disturbance Trends Observed Using Landsat Time Series

    Science.gov (United States)

    Masek, Jeffrey G.; Goward, Samuel N.; Kennedy, Robert E.; Cohen, Warren B.; Moisen, Gretchen G.; Schleeweis, Karen; Huang, Chengquan

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing U.S. land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest disturbance across the conterminous United States for 1985-2005. The geographic sample design used a probability-based scheme to encompass major forest types and maximize geographic dispersion. For each sample location disturbance was identified in the Landsat series using the Vegetation Change Tracker (VCT) algorithm. The NAFD analysis indicates that, on average, 2.77 Mha/yr of forests were disturbed annually, representing 1.09%/yr of US forestland. These satellite-based national disturbance rates estimates tend to be lower than those derived from land management inventories, reflecting both methodological and definitional differences. In particular the VCT approach used with a biennial time step has limited sensitivity to low-intensity disturbances. Unlike prior satellite studies, our biennial forest disturbance rates vary by nearly a factor of two between high and low years. High western US disturbance rates were associated with active fire years and insect activity, while variability in the east is more strongly related to harvest rates in managed forests. We note that generating a geographic sample based on representing forest type and variability may be problematic since the spatial pattern of disturbance does not necessarily correlate with forest type. We also find that the prevalence of diffuse, non-stand clearing disturbance in US forests makes the application of a biennial geographic sample problematic. Future satellite-based studies of disturbance at regional and national scales should focus on wall-to-wall analyses with annual time step for improved accuracy.

  13. An experimental assessment of vehicle disturbance effects on migratory shorebirds

    Science.gov (United States)

    Tarr, Nathan M.; Simons, T.R.; Pollock, K.H.

    2010-01-01

    Off-road vehicle (ORV) traffic is one of several forms of disturbance thought to affect shorebirds at migration stopover sites. Attempts to measure disturbance effects on shorebird habitat use and behavior at stopover sites are difficult because ORV disturbance is frequently confounded with habitat and environmental factors. We used a before-after-control-impact experimental design to isolate effects of vehicle disturbance from shorebird responses to environmental and habitat factors. We manipulated disturbance levels within beach closures along South Core Banks, North Carolina, USA, and measured changes in shorebird abundance and location, as well as the activity of one focal species, the sanderling (Calidris alba), within paired control and impact plots. We applied a discrete treatment level of one flee-response-inducing event every 10 minutes on impact plots. We found that disturbance reduced total shorebird and black-bellied plover (Pluvialis squatarola) abundance and reduced relative use of microhabitat zones above the swash zone (wet sand and dry sand) by sanderlings, black-bellied plovers, willets (Tringa semipalmata), and total shorebirds. Sanderlings and total shorebirds increased use of the swash zone in response to vehicle disturbance. Disturbance reduced use of study plots by sanderlings for resting and increased sanderling activity, but we did not detect an effect of vehicle disturbance on sanderling foraging activity. We provide the first estimates of how a discrete level of disturbance affects shorebird distributions among ocean beach microhabitats. Our findings provide a standard to which managers can compare frequency and intensity of disturbance events at other shorebird stopover and roosting sites and indicate that limiting disturbance will contribute to use of a site by migratory shorebirds. ?? 2010 The Wildlife Society.

  14. Secondary plant succession on disturbed sites at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Angerer, J.P.; Ostler, W.K.; Gabbert, W.D.; Schultz, B.W.

    1994-12-01

    This report presents the results of a study of secondary plant succession on disturbed sites created during initial site investigations in the late 1970s and early 1980s at Yucca Mountain, NV. Specific study objectives were to determine the rate and success of secondary plant succession, identify plant species found in disturbances that may be suitable for site-specific reclamation, and to identify environmental variables that influence succession on disturbed sites. During 1991 and 1992, fifty seven disturbed sites were located. Vegetation parameters, disturbance characteristics and environmental variables were measured at each site. Disturbed site vegetation parameters were compared to that of undisturbed sites to determine the status of disturbed site plant succession. Vegetation on disturbed sites, after an average of ten years, was different from undisturbed areas. Ambrosia dumosa, Chrysothamnus teretifolius, Hymenoclea salsola, Gutierrezia sarothrae, Atriplex confertifolia, Atriplex canescens, and Stephanomeria pauciflora were the most dominant species across all disturbed sites. With the exception of A. dumosa, these species were generally minor components of the undisturbed vegetation. Elevation, soil compaction, soil potassium, and amounts of sand and gravel in the soil were found to be significant environmental variables influencing the species composition and abundance of perennial plants on disturbed sites. The recovery rate for disturbed site secondary succession was estimated. Using a linear function (which would represent optimal conditions), the recovery rate for perennial plant cover, regardless of which species comprised the cover, was estimated to be 20 years. However, when a logarithmic function (which would represent probable conditions) was used, the recovery rate was estimated to be 845 years. Recommendations for future studies and site-specific reclamation of disturbances are presented.

  15. Body Image Disturbance in Patients with Acne Vulgaris

    OpenAIRE

    Bowe, Whitney P.; Doyle, Amanda K.; CRERAND, CANICE E.; Margolis, David J.; Shalita, Alan R.

    2011-01-01

    Psychosocial outcome measures, which attempt to examine acne from the patient's perspective, have become increasingly important in dermatology research. One such measure is the Body Image Disturbance Questionnaire. The authors' primary aim was to determine the validity and internal consistency of the Body Image Disturbance Questionnaire in patients with acne vulgaris. The secondary aim was to investigate the relationship between body image disturbance and quality of life. This cross-sectional...

  16. Mechanics of materials and interfaces the disturbed state concept

    CERN Document Server

    Desai, Chandrakant S

    2000-01-01

    INTRODUCTIONPreludePhilosophicalMotivationReference StatesEngineering Materials and MatterContinuous , Discontinuous or MixtureTransformation and Self AdjustmentDisturbed Sate ConceptDisturbance and Damage ModelsDSC and Other ModelsScopeTHE DISTURBED STATE CONCEPT: PreliminariesIntroductionEngineering BehaviorMechanismFully Adjusted StateCharacteristic DimensionObserved BehaviorFormulation of DSCAlternative Formulations of DSCMaterial Element Composed of Two MaterialsDSC-Multi -Component SystemDSC

  17. Vulnerability of semi-enclosed marine systems to environmental disturbances

    Digital Repository Service at National Institute of Oceanography (India)

    MacCracken, M.; Escobar-Briones, E.; Gilbert, D.; Korotaev, G.; Naqvi, S.W.A.; Perillo, G.M.E.; Rixen, T.; Stanev, E.; Sundby, B.; Thomas, H.; Unger, D.; Urban, E.R.

    , SEMSs are linked to large-scale anthropogenic disturbances through climate change, acidification from increasing levels of atmospheric carbon dioxide (C02), and atmospheric deposition of contaminants....

  18. Design of disturbances control model at automotive company

    Science.gov (United States)

    Marie, I. A.; Sari, D. K.; Astuti, P.; Teorema, M.

    2017-12-01

    The discussion was conducted at PT. XYZ which produces automotive components and motorcycle products. The company produced X123 type cylinder head which is a motor vehicle forming component. The disturbances in the production system has affected the company performance in achieving the target of Key Performance Indicator (KPI). Currently, the determination of the percentage of safety stock of cylinder head products is not in accordance to the control limits set by the company (60% - 80%), and tends to exceed the control limits that cause increasing the inventory wastage in the company. This study aims to identify the production system disturbances that occurs in the production process of manufacturing components of X123 type cylinder head products and design the control model of disturbance to obtain control action and determine the safety stock policy in accordance with the needs of the company. The design stage has been done based on the Disturbance Control Model which already existing and customized with the company need in controlling the production system disturbances at the company. The design of the disturbances control model consists of sub-model of the risk level of the disturbance, sub-model of action status, sub-model action control of the disturbance, and sub-model of determining the safety stock. The model can assist the automotive company in taking the decision to perform the disturbances control action in production system cylinder head while controlling the percentage of the safety stock.

  19. Distributed Coordination of Fractional Dynamical Systems with Exogenous Disturbances

    Directory of Open Access Journals (Sweden)

    Hongyong Yang

    2014-01-01

    Full Text Available Distributed coordination of fractional multiagent systems with external disturbances is studied. The state observer of fractional dynamical system is presented, and an adaptive pinning controller is designed for a little part of agents in multiagent systems without disturbances. This adaptive pinning controller with the state observer can ensure multiple agents' states reaching an expected reference tracking. Based on disturbance observers, the controllers are composited with the pinning controller and the state observer. By applying the stability theory of fractional order dynamical systems, the distributed coordination of fractional multiagent systems with external disturbances can be reached asymptotically.

  20. An observer with controller to detect and reject disturbances

    Science.gov (United States)

    de Jesús Rubio, José; Meléndez, Fidel; Figueroa, Maricela

    2014-03-01

    In this paper, a novel states observer is designed. This observer not only estimates the states, but also detects the disturbances by creating estimated signals. Then, both the observed states and detected disturbances are used in a control law to reject the disturbances, avoiding the requirement to know the states and disturbances. The observer is designed by the combination of the poles assignation and geometric techniques. Both the observer and controller work simultaneously. The proposed method is applied in an active suspension system and a liquid-level hydraulic system.

  1. Species richness, equitability, and abundance of ants in disturbed landscapes

    Science.gov (United States)

    Graham, J.H.; Krzysik, A.J.; Kovacic, D.A.; Duda, J.J.; Freeman, D.C.; Emlen, J.M.; Zak, J.C.; Long, W.R.; Wallace, M.P.; Chamberlin-Graham, C.; Nutter, J.P.; Balbach, H.E.

    2009-01-01

    Ants are used as indicators of environmental change in disturbed landscapes, often without adequate understanding of their response to disturbance. Ant communities in the southeastern United States displayed a hump-backed species richness curve against an index of landscape disturbance. Forty sites at Fort Benning, in west-central Georgia, covered a spectrum of habitat disturbance (military training and fire) in upland forest. Sites disturbed by military training had fewer trees, less canopy cover, more bare ground, and warmer, more compact soils with shallower A-horizons. We sampled ground-dwelling ants with pitfall traps, and measured 15 habitat variables related to vegetation and soil. Ant species richness was greatest with a relative disturbance of 43%, but equitability was greatest with no disturbance. Ant abundance was greatest with a relative disturbance of 85%. High species richness at intermediate disturbance was associated with greater within-site spatial heterogeneity. Species richness was also associated with intermediate values of the normalized difference vegetation index (NDVI), a correlate of net primary productivity (NPP). Available NPP (the product of NDVI and the fraction of days that soil temperature exceeded 25 ??C), however, was positively correlated with species richness, though not with ant abundance. Species richness was unrelated to soil texture, total ground cover, and fire frequency. Ant species richness and equitability are potential state indicators of the soil arthropod community. Moreover, equitability can be used to monitor ecosystem change. ?? 2008 Elsevier Ltd.

  2. An Industrial Model Based Disturbance Feedback Control Scheme

    DEFF Research Database (Denmark)

    Kawai, Fukiko; Nakazawa, Chikashi; Vinther, Kasper

    2014-01-01

    This paper presents a model based disturbance feedback control scheme. Industrial process systems have been traditionally controlled by using relay and PID controller. However these controllers are affected by disturbances and model errors and these effects degrade control performance. The authors...... propose a new control method that can decrease the negative impact of disturbance and model errors. The control method is motivated by industrial practice by Fuji Electric. Simulation tests are examined with a conventional PID controller and the disturbance feedback control. The simulation results...... demonstrate the effectiveness of the proposed method comparing with the conventional PID controller...

  3. Impact of benthic disturbance on megafauna in Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Rodrigues, N.; Sharma, R.; Nath, B

    .6b and c). The areas away from the disturber tracks contain resedimented particles suspended duringthe experiment. (Fig.6d). The least disturbed areas are the undisturbed ones, which have a variety of biological features such as tracks, burrows... of the impact. Most of the megabenthic life Fig. 6. Seafloor features; (a) undisturbed seafloor; (b) disturbance track; (c) sediment piles; and (d) resedimented areas. N.Rodriguesetal./Deep-SeaResearchII48(2001)3411–34263422 disappeared within disturber tracks...

  4. Evaluation of adjunct extended-release quetiapine fumarate on sleep disturbance and quality in patients with major depressive disorder and an inadequate response to on-going antidepressant therapy.

    Science.gov (United States)

    Bauer, Michael; McIntyre, Roger S; Szamosi, Johan; Eriksson, Hans

    2013-09-01

    Sleep disturbance is common in depression and is a risk factor for recurrence and suicide. This analysis evaluated the effects of adjunct extended-release quetiapine fumarate (quetiapine XR) on sleep disturbance and quality in patients with major depressive disorder (MDD) and an inadequate response to on-going antidepressant therapy. Pooled data from two 6-wk, randomized, double-blind, placebo-controlled trials were analysed post hoc. Patients received once-daily quetiapine XR [(150 mg/d), n = 309; (300 mg/d), n = 307] or placebo (n = 303) adjunct to on-going antidepressant therapy. Analyses included: change from randomization in Montgomery-Åsberg Depression Rating Scale (MADRS) Item 4 (reduced sleep) score; Hamilton Rating Scale for Depression (HAMD) Items 4 (insomnia-early), 5 (insomnia-middle) and 6 (insomnia-late) scores; HAMD sleep disturbance factor (Items 4+5+6); Pittsburgh Sleep Quality Index (PSQI) global score. Change in MADRS total score was also evaluated in patients stratified by HAMD sleep disturbance factor score (high ≥ 4 and low sleep disturbance factor and PSQI global scores from randomization vs. placebo (all p sleep disturbance, quetiapine XR (both doses) improved depressive symptoms (MADRS total score) vs. placebo from week 1 onwards (p sleep disturbance and quality vs. placebo in patients with MDD and an inadequate response to on-going antidepressant treatment, and was effective against depressive symptoms in patients experiencing high sleep disturbance.

  5. Modeling aircraft noise induced sleep disturbance

    Science.gov (United States)

    McGuire, Sarah M.

    One of the primary impacts of aircraft noise on a community is its disruption of sleep. Aircraft noise increases the time to fall asleep, the number of awakenings, and decreases the amount of rapid eye movement and slow wave sleep. Understanding these changes in sleep may be important as they could increase the risk for developing next-day effects such as sleepiness and reduced performance and long-term health effects such as cardiovascular disease. There are models that have been developed to predict the effect of aircraft noise on sleep. However, most of these models only predict the percentage of the population that is awakened. Markov and nonlinear dynamic models have been developed to predict an individual's sleep structure during the night. However, both of these models have limitations. The Markov model only accounts for whether an aircraft event occurred not the noise level or other sound characteristics of the event that may affect the degree of disturbance. The nonlinear dynamic models were developed to describe normal sleep regulation and do not have a noise effects component. In addition, the nonlinear dynamic models have slow dynamics which make it difficult to predict short duration awakenings which occur both spontaneously and as a result of nighttime noise exposure. The purpose of this research was to examine these sleep structure models to determine how they could be altered to predict the effect of aircraft noise on sleep. Different approaches for adding a noise level dependence to the Markov Model was explored and the modified model was validated by comparing predictions to behavioral awakening data. In order to determine how to add faster dynamics to the nonlinear dynamic sleep models it was necessary to have a more detailed sleep stage classification than was available from visual scoring of sleep data. An automatic sleep stage classification algorithm was developed which extracts different features of polysomnography data including the

  6. Characterization of Forest Disturbance in California using Landsat Spectral Trajectories

    Science.gov (United States)

    Reents, C.; Greenberg, J. A.

    2015-12-01

    Natural and anthropogenic forest disturbances are a major contributor to global carbon fluxes, and can act as both a natural component of healthy ecosystem function and a threat to fragile ecosystems as well as human lives and property. The local and global impacts of a disturbance event depend in large part on the timing, intensity, and cause of the disturbance. With some disturbance types expected to increase in frequency and severity under the influence of climate change and increasing anthropogenic land use, knowledge of disturbance events and trends has become particularly crucial for a variety of scientific, political and management needs. Many studies have made use of time series analyses of multitemporal satellite imagery to study forest disturbance events at a variety of scales, but few have endeavored to attribute specific causal information to the disturbances detected, particularly at broad spatial and temporal scales. The purpose of this research is to investigate the suitability of a Landsat time series approach for detecting and describing causes of disturbance events across the heterogeneous, forested landscapes of California. Using existing GIS datasets detailing the locations of logging, fire, pest damage and land use conversion events statewide, we extracted the full Landsat time series (1984-2015) for six Landsat spectral bands at the location of each disturbance event. The characteristics of each time series vary depending on the nature of the disturbance occurring at that location. These differences can be harnessed as a way of differentiating disturbance types based on observed values before, during, and after the time of the event, which together comprise the disturbance's temporal signature. We applied a machine learning algorithm to these temporal signatures in order to construct a classification model linking disturbance type with the associated signature. We then applied this model to all forested areas in California using all Landsat 4

  7. Universal randomness

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, Viktor S [Landau Institute for Theoretical Physics, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-03-31

    In the last two decades, it has been established that a single universal probability distribution function, known as the Tracy-Widom (TW) distribution, in many cases provides a macroscopic-level description of the statistical properties of microscopically different systems, including both purely mathematical ones, such as increasing subsequences in random permutations, and quite physical ones, such as directed polymers in random media or polynuclear crystal growth. In the first part of this review, we use a number of models to examine this phenomenon at a simple qualitative level and then consider the exact solution for one-dimensional directed polymers in a random environment, showing that free energy fluctuations in such a system are described by the universal TW distribution. The second part provides detailed appendix material containing the necessary mathematical background for the first part. (reviews of topical problems)

  8. How deep does disturbance go? The long-term effects of canopy disturbance on tropical forest soil biogeochemistry

    Science.gov (United States)

    Gutiérrez del Arroyo, O.; Silver, W. L.

    2015-12-01

    We used the Canopy Trimming Experiment (CTE), an ongoing ecosystem manipulation study in the Luquillo Experimental Forest (LEF), Puerto Rico to determine the decadal-scale effects of canopy disturbance and debris deposition on biogeochemistry throughout the soil profile of a wet tropical forest. These manipulations represent the most significant effects of hurricanes, which may increase in frequency or intensity with warming, strengthening their ecosystem-level effects on carbon (C) and nutrient cycling. Four replicated treatments were applied in 2005 using a complete randomized block design: canopy trimming + debris deposition, canopy trimming only, debris deposition only, and untreated control. In 2015, we sampled soils at 10 cm intervals to 1 m depth in each of 12 plots (3 per treatment). We measured gravimetric moisture content, pH, HCl and citrate-ascorbate (CA) extractable iron (Fe) species, organic (Po) and inorganic fractions of NaHCO3 and NaOH phosphorus (P), as well as total C and nitrogen (N). Soil moisture decreased markedly with depth up to ~60-70 cm, and then stabilized at ~33% down to 1 m. Across all treatments, pH increased significantly with depth, ranging from 4.6 in surface soils (0-10 cm) of trimmed plots to 5.2 in deep soils (80-90 cm) of control plots. Canopy trimming decreased pH significantly, possibly due to increased root activity in surface soils as vegetation recovered. Both HCl and CA extractable Fe showed strong depth dependance, decreasing linearly to 50 cm, and stabilizing at very low concentrations (<0.2 mg/g) down to 1 m. Inorganic P concentrations were low and did not vary significantly with depth. The majority of P was associated with organic matter, with significantly higher values in the upper soil profile (<50 cm). Debris deposition significantly increased Po, revealing the role of hurricanes in subsidizing the available soil P pool in these highly productive, low-P wet tropical forests. Debris deposition also increased soil C

  9. Random triangles

    OpenAIRE

    Matula, Dominik

    2013-01-01

    The author summarizes some previous results concerning random triangles. He describes the Gaussian triangle and random triangles whose vertices lie in a unit n-dimensional ball, in a rectangle or in a general bounded convex set. In the second part, the author deals with an inscribed triangle in a triangle - let ABC be an equilateral triangle and let M, N, O be three points, each laying on one side of the ABC. We call MNO inscribed triangle (in an equi- laterral triangle). The median triangle ...

  10. Random matrices

    CERN Document Server

    Mehta, Madan Lal

    1990-01-01

    Since the publication of Random Matrices (Academic Press, 1967) so many new results have emerged both in theory and in applications, that this edition is almost completely revised to reflect the developments. For example, the theory of matrices with quaternion elements was developed to compute certain multiple integrals, and the inverse scattering theory was used to derive asymptotic results. The discovery of Selberg's 1944 paper on a multiple integral also gave rise to hundreds of recent publications. This book presents a coherent and detailed analytical treatment of random matrices, leading

  11. The Space Technology 7 Disturbance Reduction System

    Science.gov (United States)

    O'Donnell, J. R., Jr.; Hsu, O. C.; Hanson, J.; Hruby, V.

    The Space Technology 7 Disturbance Reduction System (DRS) is an in-space technology demonstration designed to validate technologies that are required for future missions such as the Laser Interferometer Space Antenna (LISA) and the Micro-Arcsecond X-ray Imaging Mission (MAXIM). The primary sensors that will be used by DRS are two Gravitational Reference Sensors (GRSs) being developed by Stanford University. DRS will control the spacecraft so that it flies about one of the freely-floating Gravitational Reference Sensor test masses, keeping it centered within its housing. The other GRS serves as a cross-reference for the first as well as being used as a reference for the spacecraft's attitude control. Colloidal MicroNewton Thrusters being developed by the Busek Co. will be used to control the spacecraft's position and attitude using a six degree-of-freedom Dynamic Control System being developed by Goddard Space Flight Center. A laser interferometer being built by the Jet Propulsion Laboratory will be used to help validate the results of the experiment. The DRS will be launched in 2008 on the European Space Agency (ESA) LISA Pathfinder spacecraft along with a similar ESA experiment, the LISA Test Package.

  12. Trajectories of Behavioural Disturbances Across Dementia Types.

    Science.gov (United States)

    Linds, Alexandra B; Kirstein, Alana B; Freedman, Morris; Verhoeff, Nicolaas P L G; Wolf, Uri; Chow, Tiffany W

    2015-11-01

    To replicate a previous finding that the trajectory of the Neuropsychiatric Inventory (NPI) shifts in the sixth year of behavioural variant frontotemporal dementia (bvFTD). We evaluated longitudinal tracking with both the Frontal Behavioural Inventory (FBI) and NPI, comparing bvFTD against other dementias. Chart reviews over two to five years for patients with bvFTD (n=30), primary progressive aphasia (PPA, n=13) and Alzheimer's disease (AD, n=118) at an urban Canadian tertiary clinic specializing in dementia. Linear regressions of the longitudinal data tested predictors of annualized rates of change (ROC) in NPI and FBI total and subscales for apathy and disinhibition among dementia groups. The mode of the overall sample for the most advanced duration of illness observed was 5 years, with the median at 7 years. We did not find a crescendo-decrescendo pattern in scores although, for bvFTD and AD, high initial scores correlated with ensuing downward ROCs on the NPI and FBI. Educational level showed an influence on disinhibition ROCs. The FBI was no more revealing than the NPI for apathy and disinhibition scores in these dementias. A cognitive reserve effect on behavioural disturbance was supported but it may take longer than our 4 years of observing the clinical sample to record inflection points in the behavioural and psychiatric symptoms seen in bvFTD. The current data only imply that both apathy and disinhibition will diminish over the course of dementia.

  13. Eating disturbances among adolescent schoolgirls in Jordan.

    Science.gov (United States)

    Mousa, Tamara Yousef; Al-Domi, Hayder Abdullah; Mashal, Rima Hussein; Jibril, Musa Abdel-Khaleq

    2010-02-01

    Several studies indicated that the prevalence of eating disorders has increased among adolescent girls. The aim of the present study, therefore, is to investigate the occurrence and correlates of eating disorders among adolescent girls in Amman, Jordan. A sample of 432 adolescent girls aged 10-16 years were recruited from public and private schools in Amman. Information was collected from adolescent schoolgirls through a socio-demographic data sheet, eating attitude test, body shape and eating habits questionnaires. One third of participants had eating disorders, including bulimia nervosa (0.6%), binge eating disorder (1.8%) and eating disorder not otherwise specified (31%), however no anorexic cases were found. Findings also suggested that pubertal, familial and social variables were associated with eating disorders occurrence. Eating disturbances were prevalent among the present population sample. Participants have been more preoccupied with their body weight due to socio-cultural norms that are reinforced by media messages. Further research is needed to develop intervention programs to control eating disorders occurrence in Jordan. 2009 Elsevier Ltd. All rights reserved.

  14. Reproductive disturbances in multiple neuroendocrine tumor syndromes.

    Science.gov (United States)

    Lytras, Aristides; Tolis, George

    2009-12-01

    In the context of multiple neuroendocrine tumor syndromes, reproductive abnormalities may occur via a number of different mechanisms, such as hyperprolactinemia, increased GH/IGF-1 levels, hypogonadotropic hypogonadism, hypercortisolism, hyperandrogenism, hyperthyroidism, gonadotropin hypersecretion, as well as, tumorigenesis or functional disturbances in gonads or other reproductive organs. Precocious puberty and/or male feminization is a feature of McCune-Albright syndrome (MAS), neurofibromatosis type 1 (NF1), Carney complex (CNC), and Peutz-Jeghers syndrome (PJS), while sperm maturation and ovulation defects have been described in MAS and CNC. Although tumorigenesis of reproductive organs due to a multiple neuroendocrine tumor syndrome is very rare, certain lesions are characteristic and very unusual in the general population. Awareness leading to their recognition is important especially when other endocrine abnormalities coexist, as occasionally they may even be the first manifestation of a syndrome. Lesions such as certain types of ovarian cysts (MAS, CNC), pseudogynecomastia due to neurofibromas of the nipple-areola area (NF1), breast disease (CNC and Cowden disease (CD)), cysts and 'hypernephroid' tumors of the epididymis or bilateral papillary cystadenomas (mesosalpinx cysts) and endometrioid cystadenomas of the broad ligament (von Hippel-Lindau disease), testicular Sertoli calcifying tumors (CNC, PJS) monolateral or bilateral macroochidism and microlithiasis (MAS) may offer diagnostic clues. In addition, multiple neuroendocrine tumor syndromes may be complicated by reproductive malignancies including ovarian cancer in CNC, breast and endometrial cancer in CD, breast malignancies in NF1, and malignant sex-cord stromal tumors in PJS.

  15. The French Sleep Disturbance Scale for Children.

    Science.gov (United States)

    Putois, Benjamin; Leslie, Wendy; Gustin, Marie Paule; Challamel, Marie-Josèphe; Raoux, Aude; Guignard-Perret, Anne; Weick, Diane; Sauzeau, Jean-Baptiste; Herbillon, Vania; Zourou, Filio; Spruyt, Karen; Franco, Patricia

    2017-04-01

    The psychometric properties of the Sleep Disturbance Scale for Children (SDSC) have been shown to be accurate, even when translated into several languages. The aim of the present study was to translate, adapt, and validate the SDSC for a French-speaking population. After forward- and back-translation, the tool was further translated and adapted into the French language. It was then pretested in terms of clarity on 33 French-speaking parents. Pretesting demonstrated that the questionnaire was well understood, indicating good clarity. During the validation phase, a total of 447 French-speaking parents of children aged between 4 and 16  years completed the SDSC. Among these, 66 children were diagnosed with sleep disorders by a pediatric specialist after a sleep consultation and polysomnographic recordings. The factor analysis revealed five factors: difficulty in initiating and maintaining sleep (DIMS), sleep breathing disorders (SBD), disorders of excessive somnolence (DOES), parasomnias (PARA) and non-restorative sleep (NRS). This psychometric structure is reliable and logical in comparison with the experts' diagnoses. Convergent validity, divergent and internal reliability are very good. Inter-parental concordance in scoring the child's sleep problem does show differences in the ways in which parents report their children's sleep patterns. Cut-off was calculated for the total score (45). This study validated a 25-item French version of the questionnaire. The French SDSC could therefore be used to aid screening of sleep disorders in the general population. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Tai chi/yoga reduces prenatal depression, anxiety and sleep disturbances.

    Science.gov (United States)

    Field, Tiffany; Diego, Miguel; Delgado, Jeannette; Medina, Lissette

    2013-02-01

    Ninety-two prenatally depressed pregnant women were randomly assigned to a tai chi/yoga or a waitlist control group at an average of 22 weeks gestation. The tai chi/yoga group participated in a 20-min group session per week for 12 weeks. At the end of the treatment period the tai chi/yoga group had lower summary depression (CES-D) scores, as well as lower negative affect and somatic/vegetative symptoms subscale scores on the CES-D, lower anxiety (STAI) scores and lower sleep disturbances scores. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Plant hybridization: the role of human disturbance and biological invasion

    Science.gov (United States)

    Qinfeng Guo

    2014-01-01

    Aim Anderson & Stebbins (1954, Evolution, 8, 378–388) posited that human activities promote species hybridizations by creating opportunities for hybridization and new habitats for hybrids to persist through disturbances (i.e. the ‘disturbance hypothesis’). While the first part of this hypothesis appears to be well supported, the second part has...

  18. Sleep disturbances and mild cognitive impairment: A review

    Directory of Open Access Journals (Sweden)

    Renata Alves Pachota Chaves da Silva

    2015-01-01

    Conclusions: Sleep disturbance is prevalent and predictive of cognitive decline in older people and in those with neurodegenerative disorders. The sleep problems have to be identified and treat to preserve the cognition and the MCI subjects with sleep disturbances have to be follow more closely to identify the initial signs of dementia.

  19. Characterizing sleeping habits and disturbances among Saudi adults.

    Science.gov (United States)

    Al-Tannir, Mohamad; Kobrosly, Samer Y; Al-Badr, Ahmad H; Salloum, Nourhan A; Altannir, Youssef M

    2016-12-01

    To characterize sleeping habits, assess sleep disturbance prevalence, and identify associated factors among Saudi adults.  Methods: A total of 1720 adults were approached for this observational cross-sectional study between October 2014 and March 2015. The study took place in Riyadh, the capital of Saudi Arabia. We used a questionnaire to describe sleeping characteristics in relation to existing chronic diseases, smoking status, obesity, daily performance and sociodemographic variables. Results: The response rate was 79.6% (1369 participants), 61.6% have or may have sleeping disturbances of which 18.6% claimed either slowed or stopped breathing during sleep. Women reported a higher prevalence of sleep disturbances (65.2%). Feeling tired was significantly associated with sleep disturbance (49% versus 19.7%) (p greater than 0.001). Approximately 78.4% of those with sleep disturbance significantly believed that their ability to perform daily tasks is affected (p=0.005). Moreover, smoking and obesity were significantly associated with sleep disturbances (p less than 0.01). Participants with asthma, hypertension, chronic heart disease, and diabetes mellitus reported significantly more sleeping disturbance (p=0.016 to p=0.001). Conclusions: Sleep disturbances are associated with obesity, smoking, chronic health conditions, and lower performance among  Saudi adults.

  20. Interactions between predation and disturbances shape prey communities.

    Science.gov (United States)

    Karakoç, Canan; Radchuk, Viktoriia; Harms, Hauke; Chatzinotas, Antonis

    2018-02-14

    Ecological disturbances are important drivers of biodiversity patterns. Many biodiversity studies rely on endpoint measurements instead of following the dynamics that lead to those outcomes and testing ecological drivers individually, often considering only a single trophic level. Manipulating multiple factors (biotic and abiotic) in controlled settings and measuring multiple descriptors of multi-trophic communities could enlighten our understanding of the context dependency of ecological disturbances. Using model microbial communities, we experimentally tested the effects of imposed disturbances (i.e. increased dilution simulating density-independent mortality as press or pulse disturbances coupled with resource deprivation) on bacterial abundance, diversity and community structure in the absence or presence of a protist predator. We monitored the communities immediately before and after imposing the disturbance and four days after resuming the pre-disturbance dilution regime to infer resistance and recovery properties. The results highlight that bacterial abundance, diversity and community composition were more affected by predation than by disturbance type, resource loss or the interaction of these factors. Predator abundance was strongly affected by the type of disturbance imposed, causing temporary relief of predation pressure. Importantly, prey community composition differed significantly at different phases, emphasizing that endpoint measurements are insufficient for understanding the recovery of communities.

  1. Differential reactions to anthropogenic disturbance by two ground ...

    African Journals Online (AJOL)

    Birds were directly approached from over 100 m away and markers were dropped at each behavioural reaction to the approach. Measuring back allowed a quantitative measure of the effects of disturbance. Stand response distances in breeding ABO were location sensitive, which related to disturbance level, showing that ...

  2. Landscape level analysis of disturbance regimes in protected areas ...

    Indian Academy of Sciences (India)

    There is an urgent need to identify the human influence on landscape as disturbance regimes was realized for prioritization of the protected areas. The present study has attempted to describe the landscape level assessment of fragmentation and disturbance index in protected areas of Rajasthan using remote sensing and ...

  3. Plant response strategies to stress and disturbance: the case of ...

    Indian Academy of Sciences (India)

    2004-10-27

    Oct 27, 2004 ... What are the strategies of recolonization developed by plants? How high is the resilience of a disturbed system? Two theories, the intermediate disturbance hypothesis, and the patch dynamics concept proposed to predict the composition, structure and dynamics of plants due to physical-chemical factors, ...

  4. Impact of global warming on cyclonic disturbances over south Asian ...

    Indian Academy of Sciences (India)

    Keywords. Climate change; regional climate model; global warming; cyclonic disturbances; projections. ... The analysis suggests that the frequency of cyclonic disturbances forming over north Indian Ocean is likely to reduce by 9% towards the end of the present century in response to the global warming. However, the ...

  5. Republication of "Toward an Acceptable Definition of Emotional Disturbance"

    Science.gov (United States)

    Algozzine, Bob; Schmid, Rex; Conners, Bob

    2017-01-01

    Most definitions of emotionally disturbed youngsters suggest that disturbances in the child's behavior patterns cause academic and social problems which affect the child and his peers. While the process of identification may be facilitated by operational criteria within a definition, these factors are noticeably absent from definitions of…

  6. Effect of supplemental Ascorbic acid and disturbance stress on the ...

    African Journals Online (AJOL)

    The study was conducted with four hundred day-old Anak broilers to determine the effects of dietary Ascorbic acid (AA) and disturbance (D) dress on the performance of broiler chickens in a tropical environment. There were four treatments consisting of two levels of disturbance (ID) and (4D) and two levels of dietary AA (0 ...

  7. Visitor attitudes towards fire and wind disturbances in wilderness

    Science.gov (United States)

    Robert G. Dvorak; Erin D. Small

    2011-01-01

    This study examines visitor attitudes across the Boundary Waters Canoe Area Wilderness regarding the effects of natural disturbances on visitor planning and wilderness conditions. Visitors were intercepted at entry points and permit distribution locations during 2007. Results suggest that respondents were aware of recent wind and fire disturbances. Few respondents...

  8. Impacts of geo-physical factors and human disturbance on ...

    African Journals Online (AJOL)

    Species richness was correlated with environmental factors but not related to historical land use and road disturbance. Understanding the complex effects of geo-physical factors and anthropogenic disturbance is important for developing and implementing conservation strategies for the protection and restoration of ...

  9. Attributing causal agents to nationwide maps of forest disturbance

    Science.gov (United States)

    Gretchen G. Moisen; Todd A. Schroeder; Karen Schleeweis; Chris Toney; Warren B. Cohen; Samuel N. Goward

    2012-01-01

    Currently in its third phase, the North American Forest Dynamics (NAFD) project has launched nationwide processing of historic Landsat data to provide a comprehensive annual, wall-to-wall analysis of U.S. disturbance history over the last 30+ years. Because understanding the cause of disturbance is important to quantifying carbon dynamics, work is underway to attribute...

  10. United States forest disturbance trends observed with landsat time series

    Science.gov (United States)

    Jeffrey G. Masek; Samuel N. Goward; Robert E. Kennedy; Warren B. Cohen; Gretchen G. Moisen; Karen Schleweiss; Chengquan. Huang

    2013-01-01

    Disturbance events strongly affect the composition, structure, and function of forest ecosystems; however, existing US land management inventories were not designed to monitor disturbance. To begin addressing this gap, the North American Forest Dynamics (NAFD) project has examined a geographic sample of 50 Landsat satellite image time series to assess trends in forest...

  11. Thermally-Induced Structural Disturbances of Rigid Panel Solar Arrays

    Science.gov (United States)

    Johnston, John D.; Thornton, Earl A.

    1997-01-01

    The performance of a significant number of spacecraft has been impacted negatively by attitude disturbances resulting from thermally-induced motions of flexible structures. Recent examples of spacecraft affected by these disturbances include the Hubble Space Telescope (HST) and the Upper Atmosphere Research Satellite (UARS). Thermally-induced structural disturbances occur as the result of rapid changes in thermal loading typically initiated as a satellite exits or enters the Earth's shadow. Temperature differences in flexible appendages give rise to structural deformations, which in turn result in disturbance torques reacting back on the spacecraft. Structures which have proven susceptible to these disturbances include deployable booms and solar arrays. This paper investigates disturbances resulting from thermally-induced deformations of rigid panel solar arrays. An analytical model for the thermal-structural response of the solar array and the corresponding disturbance torque are presented. The effect of these disturbances on the attitude dynamics of a simple spacecraft is then investigated using a coupled system of governing equations which includes the effects of thermally-induced deformations. Numerical results demonstrate the effect of varying solar array geometry on the dynamic response of the system.

  12. Disturbance Observers for Rigid Mechanical Systems: Equivalence, Stability and Design

    NARCIS (Netherlands)

    Schrijver, E.; van Dijk, Johannes

    2002-01-01

    Mechanical (direct-drive) systems designed for high-speed and high-accuracy applications require control systems that eliminate the influence of disturbances like cogging forces and friction. One way to achieve additional disturbance rejection is to extend the usual (P(I)D) controller with a

  13. Forest economics, natural disturbances and the new ecology

    Science.gov (United States)

    Thomas P. Holmes; Robert J. Huggett; John M. Pye

    2008-01-01

    The major thesis of this chapter is that the economic analysis of forest disturbances will be enhanced by linking economic and ecologic models. Although we only review a limited number of concepts drawn generally from mathematical and empirical ecology, the overarching theme we present is that ecological models of forest disturbance processes are complex and not...

  14. Review Personality disturbance in adolescents living with HIV/AIDS ...

    African Journals Online (AJOL)

    This paper presents a review of theoretical and empirical research on personality disturbance in adolescents living with HIV/AIDS. First we discuss the relationship between mental health in adolescents and HIV/AIDS, and second we provide an overview of personality disturbance in adolescence with particular attention ...

  15. Legacy of Pre-Disturbance Spatial Pattern Determines Early Structural Diversity following Severe Disturbance in Montane Spruce Forests.

    Directory of Open Access Journals (Sweden)

    Radek Bače

    Full Text Available Severe canopy-removing disturbances are native to many temperate forests and radically alter stand structure, but biotic legacies (surviving elements or patterns can lend continuity to ecosystem function after such events. Poorly understood is the degree to which the structural complexity of an old-growth forest carries over to the next stand. We asked how pre-disturbance spatial pattern acts as a legacy to influence post-disturbance stand structure, and how this legacy influences the structural diversity within the early-seral stand.Two stem-mapped one-hectare forest plots in the Czech Republic experienced a severe bark beetle outbreak, thus providing before-and-after data on spatial patterns in live and dead trees, crown projections, down logs, and herb cover.Post-disturbance stands were dominated by an advanced regeneration layer present before the disturbance. Both major species, Norway spruce (Picea abies and rowan (Sorbus aucuparia, were strongly self-aggregated and also clustered to former canopy trees, pre-disturbance snags, stumps and logs, suggesting positive overstory to understory neighbourhood effects. Thus, although the disturbance dramatically reduced the stand's height profile with ~100% mortality of the canopy layer, the spatial structure of post-disturbance stands still closely reflected the pre-disturbance structure. The former upper tree layer influenced advanced regeneration through microsite and light limitation. Under formerly dense canopies, regeneration density was high but relatively homogeneous in height; while in former small gaps with greater herb cover, regeneration density was lower but with greater heterogeneity in heights.These findings suggest that pre-disturbance spatial patterns of forests can persist through severe canopy-removing disturbance, and determine the spatial structure of the succeeding stand. Such patterns constitute a subtle but key legacy effect, promoting structural complexity in early

  16. Active disturbance rejection control for fractional-order system.

    Science.gov (United States)

    Li, Mingda; Li, Donghai; Wang, Jing; Zhao, Chunzhe

    2013-05-01

    Fractional-order proportional-integral (PI) and proportional-integral-derivative (PID) controllers are the most commonly used controllers in fractional-order systems. However, this paper proposes a simple integer-order control scheme for fractional-order system based on active disturbance rejection method. By treating the fractional-order dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. External disturbance, sensor noise, and parameter disturbance are also estimated using extended state observer. The ADRC stability of rational-order model is analyzed. Simulation results on three typical fractional-order systems are provided to demonstrate the effectiveness of the proposed method. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Disturbance detection and isolation in the activated sludge process.

    Science.gov (United States)

    Yoo, C K; Choi, S W; Lee, I

    2002-01-01

    This paper proposes a new fault detection and isolation (FDI) method. This method monitors the distribution of process data and detects changes in this distribution, which reflect changes in the corresponding operating condition. A modified dissimilarity index and a FDI technique are defined to quantitatively evaluate the difference between data sets. This technique considers the importance of each transformed variable in the multivariate system. The FDI technique is applied to a benchmark simulation and to data from a real wastewater treatment plant. Simulation results show that it immediately detects disturbances and automatically distinguishes between serious and minor anomalies for various types of fault. The method not only detects the disturbances, but also isolates the scale of the disturbance, facilitating the interpretation of the disturbance source. The proposed monitoring technique is found to be appropriate for analyzing the biological wastewater treatment process, which is characterized by a variety of fault and disturbance sources and non-stationary characteristics.

  18. Treatment of sleep disturbances in trauma-affected refugees

    DEFF Research Database (Denmark)

    Sandahl, Hinuga; Jennum, Poul; Baandrup, Lone

    2017-01-01

    Background: Sleep disturbances are often referred to as a hallmark and as core symptoms of post-traumatic stress disorder (PTSD). Untreated sleep disturbances can contribute to the maintenance and exacerbation of PTSD symptoms, which may diminish treatment response and constitute a risk factor...... for poor treatment outcome. Controlled trials on treatment of sleep disturbances in refugees suffering from PTSD are scarce. The present study aims to examine sleep-enhancing treatment in refugees with PTSD. We aim to assess if add-on treatment with mianserin and/or Imagery Rehearsal Therapy (IRT......) to treatment as usual (TAU) for PTSD improves sleep disturbances. We will study the relation between sleep disturbances, PTSD symptoms, psychosocial functioning and quality of life. Methods: The study is a randomised controlled superiority trial with a 2 × 2 factorial design. The study will include 230 trauma...

  19. Chronic Sleep Disturbance Impairs Glucose Homeostasis in Rats

    Directory of Open Access Journals (Sweden)

    R. Paulien Barf

    2010-01-01

    Full Text Available Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory conditions. Three groups of animals were used: a sleep restriction group (RS, a group subjected to moderate sleep disturbance without restriction of sleep time (DS, and a home cage control group. To establish changes in glucose regulation, animals were subjected to intravenous glucose tolerance tests (IVGTTs before and after 1 or 8 days of sleep restriction or disturbance. Data show that both RS and DS reduce body weight without affecting food intake and also lead to hyperglycemia and decreased insulin levels during an IVGTT. Acute sleep disturbance also caused hyperglycemia during an IVGTT, yet, without affecting the insulin response. In conclusion, both moderate and severe disturbances of sleep markedly affect glucose homeostasis and body weight control.

  20. Sleep disturbance in patients with an implantable cardioverter defibrillator

    DEFF Research Database (Denmark)

    Habibović, M; Mudde, L; Pedersen, S S

    2018-01-01

    BACKGROUND: Sleep disturbances are highly prevalent in patients with cardiac diseases and associated with poor health outcomes. However, little is known about sleep disturbance in patients with an implantable cardioverter defibrillator. AIMS: We examined the prevalence and predictors of sleep...... disturbance and the impact on perceived health status in a Dutch cohort of implantable cardioverter defibrillator patients. METHODS: Patients ( n=195) enrolled in the Web-based distress program for implantable cardioverter defibrillator patients (WEBCARE) trial completed questionnaires at the time...... of implantable cardioverter defibrillator implantation, three, six and 12 months afterwards. Sleep disturbance was assessed with the corresponding item #3 of the Patient Health Questionnaire 9. RESULTS: At baseline, 67% ( n=130) reported sleep disturbance (cut off ≥1). One year later, the prevalence was 57% ( n...

  1. Model reduction of nonlinear systems subject to input disturbances

    KAUST Repository

    Ndoye, Ibrahima

    2017-07-10

    The method of convex optimization is used as a tool for model reduction of a class of nonlinear systems in the presence of disturbances. It is shown that under some conditions the nonlinear disturbed system can be approximated by a reduced order nonlinear system with similar disturbance-output properties to the original plant. The proposed model reduction strategy preserves the nonlinearity and the input disturbance nature of the model. It guarantees a sufficiently small error between the outputs of the original and the reduced-order systems, and also maintains the properties of input-to-state stability. The matrices of the reduced order system are given in terms of a set of linear matrix inequalities (LMIs). The paper concludes with a demonstration of the proposed approach on model reduction of a nonlinear electronic circuit with additive disturbances.

  2. Age structure and disturbance legacy of North American forests

    Science.gov (United States)

    Pan, Y.; Chen, J. M.; Birdsey, R.; McCullough, K.; He, L.; Deng, F.

    2011-03-01

    Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is a useful surrogate variable for analyses of the impact of disturbance on forest carbon. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project. A companion map of the standard deviations for age estimates was developed for quantifying uncertainty. We discuss the significance of the disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, by analyzing the causes of disturbances from land management and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing) this rate as a result of direct human intervention in the disturbance/age status. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

  3. Age structure and disturbance legacy of North American forests

    Directory of Open Access Journals (Sweden)

    Y. Pan

    2011-03-01

    Full Text Available Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is a useful surrogate variable for analyses of the impact of disturbance on forest carbon. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS project. A companion map of the standard deviations for age estimates was developed for quantifying uncertainty. We discuss the significance of the disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, by analyzing the causes of disturbances from land management and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing this rate as a result of direct human intervention in the disturbance/age status. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

  4. Endotoxin-induced inflammation disturbs melatonin secretion in ewe

    Directory of Open Access Journals (Sweden)

    Andrzej Przemysław Herman

    2017-12-01

    Full Text Available Objective The study examined the effect of intravenous administration of bacterial endotoxin—lipopolysaccharide (LPS —on the nocturnal secretion of melatonin and on the expression of enzymes of the melatonin biosynthetic pathway in the pineal gland of ewes, taking into account two different photoperiodic conditions: short-night (SN; n = 12 and long-night (LN; n = 12. Methods In both experiments, animals (n = 12 were randomly divided into two groups: control (n = 6 and LPS-treated (n = 6 one. Two hours after sunset, animals received an injection of LPS or saline. Blood samples were collected starting one hour after sunset and continuing for 3 hours after the treatment. The ewes were euthanized 3 hours after LPS/saline treatment. The concentration of hormones in plasma was assayed by radioimmunoassay. In the pineal gland, the content of serotonin and its metabolite was determined by HPLC; whereas the expression of examined genes and protein was assayed using real-time polymerase chain reaction and Western Blot, respectively. Results Endotoxin administration lowered (p<0.05 levels of circulating melatonin in animals from LN photoperiod only during the first hour after treatment, while in ewes from SN photoperiod only in the third hour after the injection. Inflammation more substantially suppressed biosynthesis of melatonin in ewes from SN photoperiod, which were also characterised by lower (p<0.05 cortisol concentrations after LPS treatment compared with animals from LN photoperiod. In the pineal gland of ewes subjected to SN photoperiod, LPS reduced (p<0.05 serotonin content and the expression of melatonin biosynthetic pathway enzymes, such as tryptophan hydroxylase and arylalkylamine-N-acetyltransferase. Pineal activity may be disturbed by circulating LPS and proinflammatory cytokines because the expression of mRNAs encoding their corresponding receptors was determined in this gland. Conclusion The present study showed that peripheral

  5. Satellite Monitoring of Disturbances in Arctic Ecosystems

    Science.gov (United States)

    Prieto-Blanco, A.; Disney, M.; Lewis, P.

    2008-12-01

    We explored the capability of satellite remote sensing to detect temporal changes in northern Fennoscandian regions through the application of a temporal model of surface bidirectional reflectance. Remote sensing offers the potential to monitor changes over large areas and at hard to access locations. Specifically in remote Arctic locations, where ground surveys and aircraft observations are constrained by weather conditions and logistics, remote sensing provides a unique capability for repetitive and frequent sampling. A major disturbance in mountain birch forests typical of northern Sweden and Finland is caused by outbreaks of defoliating insects such as the autumn moth (Epirrita autumnata) and the winter moth (Operophtera brumata). These outbreaks occur more or less cyclically every 9-10 years and attack mainly birch (Betula spp.) leaving a mosaic of open woodland within the forest. It is expected that global warming will affect the incidence and the intensity of this outbreaks. The ecological and economical consequences can be severe hence the importance of close monitoring of shifts in the distribution of events. Defoliated areas of up to 6000 to 7000 ha of birch forest have been reported. Severely affected areas could potentially be detected by satellite providing valuable data to understand the behavior, estimate the damage and predict the development of forest pests. Quantification of the impact of such outbreaks will also permit far more accurate estimation of the terrestrial carbon budget of such regions. Here we applied a generic algorithm to detect sudden changes on land surface cover to daily 500m MODIS surface reflectance data over the Fennoscandian area. Moderate Resolution Imaging Spectraradiometer (MODIS) sensors on board the polar orbiting satellites Terra and Aqua provide an overpass at least once a day over the area of interest. Unfortunately, frequent cloud cover limits the acquisition of satellite imagery and persistent cloud cover may

  6. Treatment of Sleep Disturbance in Alcohol Recovery: A National Survey of Addiction Medicine Physicians

    Science.gov (United States)

    Friedmann, Peter D.; Herman, Debra S.; Freedman, Shelby; Lemon, Stephenie C.; Ramsey, Susan; Stein, Michael D.

    2009-01-01

    Sleep disturbance is common among patients in recovery from alcoholism and can precipitate relapse. Though sleep complaints are commonly managed with medication, little is known about their management among recovering alcoholic patients. We performed a postal survey of a self-weighted, random systematic sample of 503 members of the American Society of Addiction Medicine (ASAM) to examine addiction medicine physicians’ medical management of sleep disturbance among patients in early recovery from alcoholism. After 3 mailings, 311 (62%) responded. Of responents, 64% have offered pharmacological treatment to an insomniac, alcoholic patient in the first 3 months after detoxification, but only 22% offered medication to more than half of such patients. Trazodone was the preferred therapy, chosen first by 38% of respondents, followed by other sedating antidepressants (12%), and antihistamines (12%). The mean duration of therapy for trazodone and other sedating antidepressants exceeded one month. Experts in addiction medicine appear reluctant to prescribe medication to sleep-disturbed patients in early recovery from alcoholism. When they do prescribe, trazodone, other sedating antidepressants and antihistamines are favored, despite limited evidence for or against this indication. Although the treatment of disordered sleep among alcoholic patients in early recovery may have merit to prevent relapse, controlled studies of these sleep agents are needed. PMID:12703672

  7. Congestion Control in TCP/AQM Networks Using a Disturbance Observer

    Science.gov (United States)

    Kubo, Ryogo; Kani, Junichi; Fujimoto, Yukihiro

    This paper presents a novel congestion controller for transmission control protocol/active queue management (TCP/AQM) networks. In order to maintain the queue length to a value less than the buffer size at the aggregation nodes, the queue management mechanism drops some packets depending on the probability calculated by a congestion controller. However, conventional controllers such as random early detection (RED) algorithms and proportional-integral-derivative (PID)-based controllers are not compatible with parameter variation in TCP/AQM networks. Parameter variation in TCP/AQM networks includes the change of the number of TCP connections, the inflow of user datagram protocol (UDP) flows and so on. In the proposed method, the effect of parameter variation is estimated as drop probability disturbance by using a disturbance observer (DOB). By using the DOB, disturbance suppression characteristics of the controlled system can be drastically improved. In addition, the TCP/AQM network system is analyzed on the basis of an acceleration control scheme. The proposed method is validated by simulation studies performed using a nonlinear model of a TCP/AQM network and verifications made using the network simulator ns-2.

  8. Neuropsychiatric disturbances associated with traumatic brain injury: a practical approach to evaluation and management.

    Science.gov (United States)

    Rao, Vani; Koliatsos, Vassilis; Ahmed, Faizi; Lyketsos, Constantine; Kortte, Kathleen

    2015-02-01

    Traumatic brain injury (TBI) causes a wide variety of neuropsychiatric disturbances associated with great functional impairments and low quality of life. These disturbances include disorders of mood, behavior, and cognition, and changes in personality. The diagnosis of specific neuropsychiatric disturbances can be difficult because there is significant symptom overlap. Systematic clinical evaluations are necessary to make the diagnosis and formulate a treatment plan that often requires a multipronged approach. Management of TBI-associated neuropsychiatric disorders should always include nonpharmacological interventions, including education, family involvement, supportive and behavioral psychotherapies, and cognitive rehabilitation. Pharmacological treatments include antidepressants, anticonvulsants, antipsychotics, dopaminergic agents, and cholinesterase inhibitors. However, evidence-based treatments are extremely limited, and management relies on clinical empiricism and resemblance of TBI neuropsychiatric symptom profiles with those of idiopathic psychiatric disorders. Although the understanding of TBI-associated neuropsychiatric disorders has improved in the last decade, further research is needed including prospective, longitudinal studies to explore biomarkers that will assist with management and prognosis as well as randomized-controlled studies to validate pharmacological and nonpharmacological treatments. The current review summarizes the available literature in support of a structured, systematic evaluation approach and treatment options as well as recommendations for further research directions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. The geocoronal responses to the geomagnetic disturbances

    Science.gov (United States)

    Kuwabara, M.; Yoshioka, K.; Murakami, G.; Tsuchiya, F.; Kimura, T.; Yamazaki, A.; Yoshikawa, I.

    2017-01-01

    Atomic hydrogen atoms in the terrestrial exosphere resonantly scatter solar Lyman alpha (121.6 nm) radiation, observed as the hydrogen geocorona. Measurements of scattered solar photons allow us to probe time-varying distributions of exospheric hydrogen atoms. The Hisaki satellite with the extreme ultraviolet spectrometer (EXtreme ultraviolet spectrosCope for ExosphEric Dynamics: EXCEED) was launched in September 2013. EXCEED acquires spectral images (52-148 nm) of the atmospheres/magnetospheres of planets from Earth orbit. Due to its low orbital altitude ( 1000 km), the images taken by the instrument also contain the geocoronal emissions. In this context, EXCEED has provided quasi-continuous remote sensing observations of the geocorona with high temporal resolution ( 1 min) since 2013. These observations provide a unique database to determine the long-term behavior of the exospheric density structure. In this paper, we report exospheric structural responses observed by EXCEED to geomagnetic disturbances. Several geomagnetic storms with decreases of Dst index occurred in February 2014 and the Lyman alpha column brightness on the night side of the Earth increased abruptly and temporarily by approximately 10%. Hisaki reveal that the time lag between the peaks of the magnetic activity and the changes in the Lyman alpha column brightness is found to be about 2 to 6 h during storms. In order to interpret the observational results, we evaluate quantitatively the factors causing the increase. On the basis of these results, a coupling effect via charge exchange between the exosphere and plasmasphere causes variations of the exospheric density structure.

  10. Travelling ionospheric disturbance over California mid 2000

    Directory of Open Access Journals (Sweden)

    M. Hawarey

    2006-01-01

    Full Text Available In this paper, the GPS data collected by more than 130 permanent GPS stations that belong to the Southern California Integrated GPS Network (SCIGN around the launch of a Minuteman-II missile on 8 July 2000 (UTC is processed to reveal traveling ionospheric disturbance (TID all over the network on average 15 min after the launch. This TID was initially perceived to be excited by the launch itself, but this conclusion is challenged by the propagation direction. This is because this TID seems to travel towards the air force base from where the launch took place, not far away from it. This challenge is based on the assumption that TID is occurring at one single ionospheric altitude. While the nature of ionosphere supports such horizontally-guided propagation, multi-altitude ionospheric pierce points are hypothesized, which would support the suggestion that detected TID is excited by the missile launch itself, despite the apparent reverse direction of propagation. The overall analysis rules out any extra-terrestrial sources like solar flares, or seismic sources like earthquakes, which confirms the conclusion of TID excitation by the launch. There is apparent coherence of the TID for about 45 min and the propagation speed of TID within the layer of ionosphere is calculated to be approximately equal to 1230 m/s. While the usual assumption for TID is that they occur around an altitude of 350 km, such sound speed can only occur at much higher altitudes. Further research is recommended to accurately pinpoint the ionospheric pierce points and develop an algorithm to locate the source of TID in case it is totally unknown.

  11. [Pain and sensory disturbance in Parkinson disease].

    Science.gov (United States)

    Yoshii, Fumihito

    2012-04-01

    Pain or sensory symptoms are a frequent complaint in Parkinson disease (PD), which reduce health-related quality of life (QOL) and interfere with patient's ability to participate in activities of daily living, thus contributing to sleep disturbance or major depression. The frequency of pain is thought to have a bimodal distribution. The initial peak seems to occur before, or at the onset of PD and a second peak occurs later in the disease course in conjunction with the development of motor fluctuations or dyskinesia. The spectrum of sensory symptoms is wide, and the most common sites that experience pain are the back, legs, and shoulders. In cases, pain occurs on the side that is more affected by parkinsonism; however unusual distributions, such as oral or genital pain syndrome, chest pain, and upper or lower abdominal discomfort may be observed. The etiological basis of PD-related pain is multifactorial, with varying degrees of contribution from peripheral and central sources. Central mechanisms include derangement of the intrinsic pain-modulating monoaminergic mechanism in addition to plastic central nervous system changes induced by chronic anti-parkinsonian medication. The importance of dopaminergic deficits as a causal factor in PD-related pain is supported by the normalization of these abnormalities after L-dopa administration, which suggests that the human striatum plays a central role in processing nociceptive information. Nevertheless, the lack of response to dopaminergic agents in some patients suggests the involvement of non-dopaminergic structures in PD. Abnormalities of noradrenergic and serotonergic pathways descending to the spinal cord are assumed to play a role in pain perception in PD. Some reports have highlighted the problem of delayed diagnosis in PD patients with an initial presentation of pain. Greater awareness of this possibility among physicians is important. Physicians also should bear in mind that psychological factors are major

  12. Pharmacotherapies for sleep disturbances in dementia.

    Science.gov (United States)

    McCleery, Jenny; Cohen, Daniel A; Sharpley, Ann L

    2016-11-16

    Sleep disturbances, including reduced nocturnal sleep time, sleep fragmentation, nocturnal wandering, and daytime sleepiness are common clinical problems in dementia, and are associated with significant caregiver distress, increased healthcare costs, and institutionalisation. Drug treatment is often sought to alleviate these problems, but there is significant uncertainty about the efficacy and adverse effects of the various hypnotic drugs in this vulnerable population. To assess the effects, including common adverse effects, of any drug treatment versus placebo for sleep disorders in people with dementia, through identification and analysis of all relevant randomised controlled trials (RCTs). We searched ALOIS (www.medicine.ox.ac.uk/alois), the Cochrane Dementia and Cognitive Improvement Group's Specialized Register, in March 2013 and again in March 2016, using the terms: sleep, insomnia, circadian, hypersomnia, parasomnia, somnolence, rest-activity, sundowning. We included RCTs that compared a drug with placebo, and that had the primary aim of improving sleep in people with dementia who had an identified sleep disturbance at baseline. Trials could also include non-pharmacological interventions, as long as both drug and placebo groups had the same exposure to them. Two review authors independently extracted data on study design, risk of bias, and results from the included study reports. We obtained additional information from study authors where necessary. We used the mean difference as the measure of treatment effect, and where possible, synthesized results using a fixed-effect model. We found six RCTs eligible for inclusion for three drugs: melatonin (222 participants, four studies, but only two yielded data on our primary sleep outcomes suitable for meta-analysis), trazodone (30 participants, one study), and ramelteon (74 participants, one study, no peer-reviewed publication, limited information available).The participants in the trazodone study and almost all

  13. Correlates and Escitalopram Treatment Effects on Sleep Disturbance in Patients with Acute Coronary Syndrome: K-DEPACS and EsDEPACS.

    Science.gov (United States)

    Kim, Jae-Min; Stewart, Robert; Bae, Kyung-Yeol; Kang, Hee-Ju; Kim, Sung-Wan; Shin, Il-Seon; Hong, Young Joon; Ahn, Youngkeun; Jeong, Myung Ho; Yoon, Jin-Sang

    2015-07-01

    To investigate the correlates of sleep disturbance and to assess escitalopram treatment effects of depression on sleep disturbance in patients with acute coronary syndrome (ACS). A cross-sectional study in patients with ACS within 2 w post-ACS, and a 24-w double-blind controlled trial of escitalopram against placebo for patients with ACS who have comorbid depressive disorders. A university hospital in South Korea. There were 1,152 patients with ACS who were consecutively recruited. Of 446 patients with comorbid depressive disorders, 300 were randomized to the trial. Sleep disturbance was evaluated by the Leeds Sleep Evaluation Questionnaire. Demographic and clinical characteristics were assessed, including cardiovascular risk factors, current cardiac status, and depressive symptoms. Depressive symptoms were most strongly and consistently associated with sleep disturbance. In addition, older age, female sex, hypertension, and more severe ACS status were associated with certain aspects of sleep disturbance. Escitalopram was significantly superior to placebo for improving sleep disturbance over the 24-w treatment period. These effects were substantially explained by improvement in depressive symptoms. Depression screening is indicated in patients with acute coronary syndrome with sleep disturbance. Successful treatment of depression has beneficial effects on sleep outcomes in these patients. ClinicalTrial.gov identifier for the 24-w drug trial, NCT00419471. © 2015 Associated Professional Sleep Societies, LLC.

  14. Behavioral parent training to address sleep disturbances in young children with autism spectrum disorder: a pilot trial.

    Science.gov (United States)

    Johnson, Cynthia R; Turner, Kylan S; Foldes, Emily; Brooks, Maria M; Kronk, Rebecca; Wiggs, Luci

    2013-10-01

    A large percentage of children with autism spectrum disorders (ASD) have bedtime and sleep disturbances. However, the treatment of these disturbances has been understudied. The purpose of our study was to develop a manualized behavioral parent training (BPT) program for parents of young children with ASD and sleep disturbances and to test the feasibility, fidelity, and initial efficacy of the treatment in a small randomized controlled trial (RCT). Parents of a sample of 40 young children diagnosed with ASD with an average age of 3.5years were enrolled in our study. Participants were randomized to either the BPT program group or a comparison group who were given nonsleep-related parent education. Each participant was individually administered a 5-session program delivered over the 8-week study. Outcome measures of feasibility, fidelity, and efficacy were collected at weeks 4 and 8 after the baseline time point. Children's sleep was assessed by parent report and objectively by actigraphy. Of the 20 participants in each group, data were available for 15 participants randomized to BPT and 18 participants randomized to the comparison condition. Results supported the feasibility of the manualized parent training program and the comparison program. Treatment fidelity was high for both groups. The BPT program group significantly improved more than the comparison group based on the primary sleep outcome of parent report. There were no objective changes in sleep detected by actigraphy. Our study is one of few RCTs of a BPT program to specifically target sleep disturbances in a well-characterized sample of young children with ASD and to demonstrate the feasibility of the approach. Initial efficacy favored the BPT program over the comparison group and suggested that this manualized parent training approach is worthy of further examination of the efficacy within a larger RCT. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Theory meets practice: the localization of wraparound services for youth with serious emotional disturbance.

    Science.gov (United States)

    Mendenhall, Amy N; Kapp, Stephen A; Rand, April; Robbins, Mary Lee; Stipp, Karen

    2013-12-01

    This study identified statewide variation in implementation of wraparound for children on the severe emotional disturbance (SED) Waiver in Kansas. SED Waivers allow Community Mental Health Centers (CMHC) to offer an array of community-based services to high risk youth. Qualitative methods, including interviews, reviews of charts and billing records, and a survey, were employed. Stratified random sampling was used to select seven CMHCs, and random sampling was used to select individual cases for interviews. Although CMHCs shared similar wraparound philosophy and service initiation processes, each developed their own localized wraparound model within the confines of Medicaid eligibility and documentation rules. Eight models for wraparound team composition were identified. Findings demonstrate implementation of wraparound with fidelity to a central model is difficult on a large scale. The balance of standardized wraparound practices, localized innovations, and agency compliance with Medicaid is essential for optimizing children's mental health services.

  16. Effect of intermittent aerobic exercise on sleep quality and sleep disturbances in patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Løppenthin, Katrine; Esbensen, Bente Appel; Jennum, Poul

    2014-01-01

    of an intermittent aerobic exercise intervention on sleep, assessed both objectively and subjectively in patients with rheumatoid arthritis. METHODS/DESIGN: A randomized controlled trial including 44 patients with rheumatoid arthritis randomly assigned to an exercise training intervention or to a control group....... The intervention consists of 18 session intermittent aerobic exercise training on a bicycle ergometer three times a week. Patients are evaluated according to objective changes in sleep as measured by polysomnography (primary outcome). Secondary outcomes include changes in subjective sleep quality and sleep...... disturbances, fatigue, pain, depressive symptoms, physical function, health-related quality of life and cardiorespiratory fitness. DISCUSSION: This trial will provide evidence of the effect of intermittent aerobic exercise on the improvement of sleep in patients with rheumatoid arthritis, which is considered...

  17. Automated Detection and Annotation of Disturbance in Eastern Forests

    Science.gov (United States)

    Hughes, M. J.; Chen, G.; Hayes, D. J.

    2013-12-01

    Forest disturbances represent an important component of the terrestrial carbon budget. To generate spatially-explicit estimates of disturbance and regrowth, we developed an automated system to detect and characterize forest change in the eastern United States at 30 m resolution from a 28-year Landsat Thematic Mapper time-series (1984-2011). Forest changes are labeled as 'disturbances' or 'regrowth', assigned to a severity class, and attributed to a disturbance type: either fire, insects, harvest, or 'unknown'. The system generates cloud-free summertime composite images for each year from multiple summer scenes and calculates vegetation indices from these composites. Patches of similar terrain on the landscape are identified by segmenting the Normalized Burn Ratio image. The spatial variance within each patch, which has been found to be a good indicator of diffuse disturbances such as forest insect damage, is then calculated for each index, creating an additional set of indexes. To identify vegetation change and quantify its degree, the derivative through time is calculated for each index using total variance regularization to account for noise and create a piecewise-linear trend. These indexes and their derivatives detect areas of disturbance and regrowth and are also used as inputs into a neural network that classifies the disturbance type/agent. Disturbance and disease information from the US Forest Service Aerial Detection Surveys (ADS) geodatabase and disturbed plots from the US Forest Service Forest Inventory and Analysis (FIA) database provided training data for the neural network. Although there have been recent advances in discriminating between disturbance types in boreal forests, due to the larger number of forest species and cosmopolitan nature of overstory communities in eastern forests, separation remains difficult. The ADS database, derived from sketch maps and later digitized, commonly designates a single large area encompassing many smaller effected

  18. The disturbing function for asteroids with arbitrary inclinations

    Science.gov (United States)

    Namouni, F.; Morais, M. H. M.

    2018-02-01

    The classical disturbing function of the three-body problem widely used in planetary dynamics studies is an expansion of the gravitational interaction of the three-body problem with respect to zero eccentricity and zero inclination. This restricts its validity to nearly coplanar orbits. Motivated by the dynamical study of asteroids, Centaurs and transneptunian objects with arbitrary inclinations, we derive a series expansion of the gravitational interaction with respect to an arbitrary reference inclination that generalises our work on the polar and retrograde disturbing functions. The new disturbing function, like the polar one, may model any resonance as expansion order is unrelated to resonance order. The powers of eccentricity and inclination of the force amplitude of a $p$:$q$ resonance depend only on the parity of the resonance order $|p-q|$. Disturbing functions with non zero reference inclinations are thus physically different from the classical disturbing function as the former are based on the three-dimensional three-body problem and the latter on the two-dimensional one. We illustrate the use of the new disturbing function by showing that what is known as pure eccentricity resonances are intrinsically dependent on inclination contrary to the prediction of the classical disturbing function. We determine the inclination dependence of the resonance widths of the 2:1 and 3:1 prograde and retrograde inner resonances with Jupiter as well as those of the asymmetric librations of the 1:2 and 1:3 prograde outer resonances with Neptune.

  19. Induced Disturbances Cause Monomorium pharaonis (Hymenoptera: Formicidae) Nest Relocation.

    Science.gov (United States)

    Tay, Jia-Wei; Lee, Chow-Yang

    2015-06-01

    Budding and relocation of nests are important characteristics of the Pharaoh ant, Monomorium pharaonis (L.), an important pest of artificial structures. Pharaoh ant colony movements induced by several types of disturbances were evaluated in the laboratory. The percentages of workers and brood in the source and new nest sites were determined at Days 0, 1, 3, and 5 following physical disturbance (temporal removal of nestmates), chemical disturbance (application of pyrethroid insecticide), invasion by heterospecific ants, food depletion, and moisture depletion in the laboratory. All disturbances were performed in the source nest, which was connected to an empty new nest site. Almost all workers moved and carried the entire brood to the new nest site when subjected to physical disturbance, chemical disturbance, and ant invasion on Day 1, whereas only nest site in the undisturbed control. After these disturbances, the brood was never relocated back to the original nest site in this 5-d study. When subjected to food depletion, ∼60% of the brood were found in the new nest site and ∼40% of the brood remained in the original nest on Day 5, resulting in a polydomous population. In contrast, moisture depletion did not show any significant effect on colony movement. These results provide useful information about the causes of Pharaoh ant colony budding and guidance about how to develop effective control and prevention strategies. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Purpose in life and incidence of sleep disturbances.

    Science.gov (United States)

    Kim, Eric S; Hershner, Shelley D; Strecher, Victor J

    2015-06-01

    Purpose in life has been linked with better mental health, physical health, and health behaviors, but the association between purpose and sleep is understudied. Sleep disturbances increase with age and as the number of older adults rapidly increases, it is ever more important to identify modifiable factors that are associated with reduced incidence of sleep disturbances. We used multiple logistic regression models and data from the Health and Retirement Study, a nationally representative panel study of American adults over the age of 50, to examine whether higher purpose was linked with a reduced incidence of sleep disturbances. Among 4144 respondents reporting minimal or no sleep disturbances at baseline, higher purpose was associated with a lower incidence of sleep disturbances over the 4-year follow-up. After adjusting for sociodemographic factors, each unit increase in purpose (on a six-point scale) was associated with a 16 % reduced odds of developing sleep disturbances (OR 0.84, 95 % CI 0.77-0.92). The association between purpose and sleep disturbances remained after adjusting for sociodemographic, behavioral, psychological, and health covariates. Should future research replicate our findings, this area of research may lead to innovative efforts that improve the quality of sleep in older adults.

  1. A Landsat Record of North American Forest Disturbance

    Science.gov (United States)

    Masek, J.; Hall, F. G.; Huang, C.; Wolfe, R.

    2005-12-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) is generating a decadal, wall-to-wall analysis of forest disturbance and recovery from Landsat satellite imagery for the period 1975-2000. The intent is to provide an accurate, high-resolution view of forest disturbance to support biogeochemical modeling and carbon accounting for the North American Carbon Program (NACP). Through the NASA Science Data Purchase program, substantially cloud-free Landsat MSS, TM, and ETM+ data were selected from the global archive and orthorectified to a UTM map base. The LEDAPS project has calibrated and atmospherically corrected these data (~2100 TM and ETM+ scenes to date) using the MODIS/6S radiative transfer approach. Forest disturbance and recovery is then calculated from the surface reflectance images using change detection techniques. An empirical spectral index (the `Disturbance Index') is used to classify pixels into classes exhibiting high rates of biomass loss over ten years (disturbance) or high rates of biomass gain (recovery). Initial results from North America show good correlation with areas of known harvest activity (Southeastern US, Maine, Pacific Northwest) and fire activity (Boreal forests). Additional work is concentrating on the use of canopy reflectance models to quantify changes in canopy properties in order to identify more subtle changes due to partial harvest and thinning. Initial versions of the surface reflectance and Disturbance Index products were released during 2005 (http://ledaps.nascom.nasa.gov/ledaps/ledaps_NorthAmerica.html).

  2. Body image disturbance in patients with acne vulgaris.

    Science.gov (United States)

    Bowe, Whitney P; Doyle, Amanda K; Crerand, Canice E; Margolis, David J; Shalita, Alan R

    2011-07-01

    Psychosocial outcome measures, which attempt to examine acne from the patient's perspective, have become increasingly important in dermatology research. One such measure is the Body Image Disturbance Questionnaire. The authors' primary aim was to determine the validity and internal consistency of the Body Image Disturbance Questionnaire in patients with acne vulgaris. The secondary aim was to investigate the relationship between body image disturbance and quality of life. This cross-sectional investigation included 52 consecutive acne patients presenting to an outpatient dermatology clinic. Subjects completed the Body Image Disturbance Questionnaire, Skindex-16, and other body image and psychosocial functioning measures. An objective assessment of acne was performed. The Body Image Disturbance Questionnaire was internally consistent and converged with other known body image indices. Body Image Disturbance Questionnaire scores also correlated with Skindex-16 scores, confirming that quality of life and body image are related psychosocial constructs. The Body Image Disturbance Questionnaire appears to be an accurate instrument that can assess appearance-related concern and impairment in patients with acne vulgaris. Limitations include a small sample size and the cross-sectional design.

  3. Impact of Unsteady Disturbance on Multi-lane Traffic Flow

    Science.gov (United States)

    Sasoh, Akihiro

    2002-03-01

    In this paper, we study on multi-lane traffic flow of up to four lanes experiencing non-linear, unsteady disturbance. The analysis is done based on car-following computation using a modified optimal velocity model. The unsteady disturbance to homogeneous flow is exerted as the stop-and-go motion of the leading car in the first lane. The strength of the disturbance is quantified with the duration time of the stop; its effect is evaluated from the time variation of local car flux. In general, multi-lane flow is less sensitive to the strength of the disturbance than single-lane flow is. In the multi-lane flow, once a weak disturbance causes a triggering lane change, it in turn induces successive disturbances and lane changes, eventually forming much fluctuated flow. Therefore, the strength of the initial disturbance becomes less important. The degradation in the car flux of such fluctuated multi-lane flow is better than that in unstable single-lane flow. The transient car flux is influenced mainly by the value of the relaxation time appearing in the equation of motion along lanes, and is less sensitive to the number of lanes.

  4. Mapping post-disturbance stand age distribution in Siberian larch forest based on a novel method

    Science.gov (United States)

    Chen, D.; Loboda, T. V.; Krylov, A.; Potapov, P.

    2014-12-01

    The Siberian larch forest, which accounts for nearly 20% of the global boreal forest biome, is unique, important, yet significantly understudied. These deciduous needleleaf forests with a single species dominance over a large continuous area are not found anywhere except the extreme continental zones of Siberia and the Russian Far East. Most of these forests are located in remote and sparsely populated areas and, therefore, little is known about spatial variability of their structure and dynamics. Wall-to-wall repeated observations of this area are available only since the 2000s. Previously, we developed methods for reconstruction of stand-age distribution from a sample of 1980-2000 disturbances in Landsat TM and ETM+ imagery. However, availability of those images in Siberian larch forests is particularly limited. Built upon the hypothesis that the spectral characteristics of the disturbed forest in the region change with time consistently, this paper proposes a novel method utilizing the newly released Global Forest Change (GFC) 2000-2012 dataset. We exploit the data-rich era of annual forest disturbance samples identified between 2000 and 2012 in the Siberian larch forest by the GFC dataset to build a robust training set of spectral signatures from regrowing larch forests as they appear in Landsat imagery in 2012. The extracted statistics are ingested into a random forest, which predicts the approximate stand age for every forested pixel in the circa 2000 composite. After merging the estimated stand age distribution for 1989-2000 with the observed disturbance records for 2001-2012, a gap-free 30 m resolution 24-year long record of stand age distribution is obtained. A preliminary accuracy assessment against the Advanced Very High Resolution Radiometer (AVHRR) burned area product suggested satisfactory performance of the proposed method.

  5. Geomagnetic response to solar and interplanetary disturbances

    Directory of Open Access Journals (Sweden)

    Maris Georgeta

    2013-07-01

    Full Text Available The space weather discipline involves different physical scenarios, which are characterised by very different physical conditions, ranging from the Sun to the terrestrial magnetosphere and ionosphere. Thanks to the great modelling effort made during the last years, a few Sun-to-ionosphere/thermosphere physics-based numerical codes have been developed. However, the success of the prediction is still far from achieving the desirable results and much more progress is needed. Some aspects involved in this progress concern both the technical progress (developing and validating tools to forecast, selecting the optimal parameters as inputs for the tools, improving accuracy in prediction with short lead time, etc. and the scientific development, i.e., deeper understanding of the energy transfer process from the solar wind to the coupled magnetosphere-ionosphere-thermosphere system. The purpose of this paper is to collect the most relevant results related to these topics obtained during the COST Action ES0803. In an end-to-end forecasting scheme that uses an artificial neural network, we show that the forecasting results improve when gathering certain parameters, such as X-ray solar flares, Type II and/or Type IV radio emission and solar energetic particles enhancements as inputs for the algorithm. Regarding the solar wind-magnetosphere-ionosphere interaction topic, the geomagnetic responses at high and low latitudes are considered separately. At low latitudes, we present new insights into temporal evolution of the ring current, as seen by Burton’s equation, in both main and recovery phases of the storm. At high latitudes, the PCC index appears as an achievement in modelling the coupling between the upper atmosphere and the solar wind, with a great potential for forecasting purposes. We also address the important role of small-scale field-aligned currents in Joule heating of the ionosphere even under non-disturbed conditions. Our scientific results in

  6. A succession of theories: purging redundancy from disturbance theory.

    Science.gov (United States)

    Pulsford, Stephanie A; Lindenmayer, David B; Driscoll, Don A

    2016-02-01

    The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional

  7. Ipsilateral sensory disturbances in Complex Regional Pain Syndrome (CRPS)

    DEFF Research Database (Denmark)

    Knudsen, Lone

    a disturbance in central nociceptive pathways processing input from hemilateral body sites. However, it may also be consistent with referred pain and cortical reorganization. Thus, it is important to assess whether sensory disturbances spread to ipsilateral body sites other than the forehead. The aim...... hyperalgesia to sharpness were not related to age, pain intensity, or pain duration. 2 Conclusions: The findings suggest the presence of heightened excitability in nociceptive pathways in CRPS, particularly those that provide hemilateral input, perhaps due to disturbances in pain control from thalamus...

  8. A ring of traveling ionospheric disturbances around Moscow megapolis

    Science.gov (United States)

    Zakharov, V. I.; Gorchakov, G. I.; Kunitsyn, V. E.

    2017-02-01

    According to interferometric data of radio waves from GPS satellites, which are received in Moscow region on the stations of the Moscow Navigation-Geodesic Support Network and the International Geophysical Survey (IGS) network, traveling ionospheric disturbances are detected moving from the Moscow megapolis and forming a ring around it. The empirical velocity distribution functions of this movement, the observed duration, and the direction of propagation of these disturbances are presented. It is shown that the observed traveling ionospheric disturbances may be due to the urban heat island effect.

  9. FEATURES OF COGNITIVE DISTURBANCES AT THE ARTERIAL HYPERTENSIA

    Directory of Open Access Journals (Sweden)

    E.V. Sevastyanova

    2008-03-01

    Full Text Available The questions of diagnostics and classification of cognitive disturbances in 112 patients with hypertensive encephalopathy are considered. The diagnosis of cognitive frustration was based on results of expanded neuropsychological examination with a qualitative and quantitative estimation of the received results. 56 % of the examined patients had the moderate cognitive disturbance syndrome. Neurodinamical-disregulation and primary-dismnestical types have been revealed. Taking into account, that opportunities of treatment and rehabilitation of patients with dementia noware rather limited, the study of predementical forms of cognitive disturbances when therapeutic actions are considered to be the most effective and of great importance.

  10. Psychopharmacologic management of serious behavioral disturbance in ASD.

    Science.gov (United States)

    Stigler, Kimberly A

    2014-01-01

    Individuals diagnosed with autism spectrum disorders (ASD) often exhibit serious behavioral disturbance (irritability) including severe tantrums, aggression, and self-injury that requires pharmacologic management. Research focused on the treatment of severe irritability has primarily involved the atypical antipsychotics, including risperidone and aripiprazole. Anticonvulsants have also been investigated for targeting serious behavioral disturbance; however findings have been mixed. Advances in the pharmacotherapy of irritability in ASD continue to inform practice. Research is needed to develop safer and more effective drug treatments for serious behavioral disturbance in this population. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Disturbance observer based Takagi-Sugeno fuzzy control for an active seat suspension

    Science.gov (United States)

    Ning, Donghong; Sun, Shuaishuai; Zhang, Fei; Du, Haiping; Li, Weihua; Zhang, Bangji

    2017-09-01

    In this paper, a disturbance observer based Takagi-Sugeno (TS) fuzzy controller is proposed for an active seat suspension; both simulations and experiments have been performed verifying the performance enhancement and stability of the proposed controller. The controller incorporates closed-loop feedback control using the measured acceleration of the seat and deflection of the suspension; these two variables can be easily measured in practical applications, thus allowing the proposed controller to be robust and adaptable. A disturbance observer that can estimate the disturbance caused by friction, model simplification, and controller output error has also been used to compensate a H∞ state feedback controller. The TS fuzzy control method is applied to enhance the controller's performance by considering the variation of driver's weight during operation. The vibration of a heavy duty vehicle seat is largest in the frequency range between 2 Hz and 4 Hz, in the vertical direction; therefore, it is reasonable to focus on controlling low frequency vibration amplitudes and maintain the seat suspensions passivity at high frequency. Moreover, both the simulation and experimental results show that the active seat suspension with the proposed controller can effectively isolate unwanted vibration amplitudes below 4.5 Hz, when compared with a well-tuned passive seat suspension. The active controller has been further validated under bump and random road tests with both a 55 kg and a 70 kg loads. The bump road test demonstrated the controller has good transient response capabilities. The random road test result has been presented both in the time domain and the frequency domain. When with the above two loads, the controlled seat suspensions root-mean-square (RMS) accelerations were reduced by 45.5% and 49.5%, respectively, compared with a well-tuned passive seat suspension. The proposed active seat suspension controller has great potential and is very practical for application

  12. Patch-Scale Effects of Equine Disturbance on Arthropod Assemblages and Vegetation Structure in Subalpine Wetlands

    Science.gov (United States)

    Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Ballenger, Elizabeth A.

    2014-06-01

    Assessments of vertebrate disturbance to plant and animal assemblages often contrast grazed versus ungrazed meadows or other larger areas of usage, and this approach can be powerful. Random sampling of such habitats carries the potential, however, for smaller, more intensely affected patches to be missed and for other responses that are only revealed at smaller scales to also escape detection. We instead sampled arthropod assemblages and vegetation structure at the patch scale (400-900 m2 patches) within subalpine wet meadows of Yosemite National Park (USA), with the goal of determining if there were fine-scale differences in magnitude and directionality of response at three levels of grazing intensity. Effects were both stronger and more nuanced than effects evidenced by previous random sampling of paired grazed and ungrazed meadows: (a) greater negative effects on vegetation structure and fauna in heavily used patches, but (b) some positive effects on fauna in lightly grazed patches, suggested by trends for mean richness and total and population abundances. Although assessment of disturbance at either patch or landscape scales should be appropriate, depending on the management question at hand, our patch-scale work demonstrated that there can be strong local effects on the ecology of these wetlands that may not be detected by comparing larger scale habitats.

  13. Random walks in a random environment

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Random walks as well as diffusions in random media are considered. Methods are developed that allow one to establish large deviation results for both the 'quenched' and the 'averaged' case. Keywords. Large deviations; random walks in a random environment. 1. Introduction. A random walk on Zd is a stochastic ...

  14. Temporal and spatial evolution characteristics of disturbance wave in a hypersonic boundary layer due to single-frequency entropy disturbance.

    Science.gov (United States)

    Wang, Zhenqing; Tang, Xiaojun; Lv, Hongqing; Shi, Jianqiang

    2014-01-01

    By using a high-order accurate finite difference scheme, direct numerical simulation of hypersonic flow over an 8° half-wedge-angle blunt wedge under freestream single-frequency entropy disturbance is conducted; the generation and the temporal and spatial nonlinear evolution of boundary layer disturbance waves are investigated. Results show that, under the freestream single-frequency entropy disturbance, the entropy state of boundary layer is changed sharply and the disturbance waves within a certain frequency range are induced in the boundary layer. Furthermore, the amplitudes of disturbance waves in the period phase are larger than that in the response phase and ablation phase and the frequency range in the boundary layer in the period phase is narrower than that in these two phases. In addition, the mode competition, dominant mode transformation, and disturbance energy transfer exist among different modes both in temporal and in spatial evolution. The mode competition changes the characteristics of nonlinear evolution of the unstable waves in the boundary layer. The development of the most unstable mode along streamwise relies more on the motivation of disturbance waves in the upstream than that of other modes on this motivation.

  15. Stochastic analysis of a novel nonautonomous periodic SIRI epidemic system with random disturbances

    Science.gov (United States)

    Zhang, Weiwei; Meng, Xinzhu

    2018-02-01

    In this paper, a new stochastic nonautonomous SIRI epidemic model is formulated. Given that the incidence rates of diseases may change with the environment, we propose a novel type of transmission function. The main aim of this paper is to obtain the thresholds of the stochastic SIRI epidemic model. To this end, we investigate the dynamics of the stochastic system and establish the conditions for extinction and persistence in mean of the disease by constructing some suitable Lyapunov functions and using stochastic analysis technique. Furthermore, we show that the stochastic system has at least one nontrivial positive periodic solution. Finally, numerical simulations are introduced to illustrate our results.

  16. Global synchronization of memristive neural networks subject to random disturbances via distributed pinning control.

    Science.gov (United States)

    Guo, Zhenyuan; Yang, Shaofu; Wang, Jun

    2016-12-01

    This paper presents theoretical results on global exponential synchronization of multiple memristive neural networks in the presence of external noise by means of two types of distributed pinning control. The multiple memristive neural networks are coupled in a general structure via a nonlinear function, which consists of a linear diffusive term and a discontinuous sign term. A pinning impulsive control law is introduced in the coupled system to synchronize all neural networks. Sufficient conditions are derived for ascertaining global exponential synchronization in mean square. In addition, a pinning adaptive control law is developed to achieve global exponential synchronization in mean square. Both pinning control laws utilize only partial state information received from the neighborhood of the controlled neural network. Simulation results are presented to substantiate the theoretical results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Robust Helicopter Stabilization in the Face of Wind Disturbance

    DEFF Research Database (Denmark)

    A. Danapalasingam, Kumeresan; Leth, John-Josef; la Cour-Harbo, Anders

    2010-01-01

    When a helicopter is required to hover with minimum deviations from a desired position without measurements of an affecting persistent wind disturbance, a robustly stabilizing control action is vital. In this paper, the stabilization of the position and translational velocity of a nonlinear...... controller is then designed based on nonlinear adaptive output regulations and robust stabilization of a chain of integrators by a saturated feedback. Simulation results show the effectiveness of the control design in the stabilization of helicopter motion and the built-in robustness of the controller...... helicopter model affected by a wind disturbance is addressed. The wind disturbance is assumed to be a sum of a fixed number of sinusoids with unknown amplitudes, frequencies and phases. An estimate of the disturbance is introduced to be adapted using state measurements for control purposes. A nonlinear...

  18. BIM and GIS for low-disturbance construction

    NARCIS (Netherlands)

    Sebastian, R.; Böhms, H.M.; Helm, P.W. van den

    2013-01-01

    Construction and maintenance activities of bridges often bring negative impacts to the urban environment in terms of disturbance, traffic jams and disruptions, noise, dust, and air pollution. Lack of coordination between the stakeholders in strategic, tactical and operational construction planning

  19. Practical Active Disturbance Rejection Solution for Furnace Temperature Control System

    Directory of Open Access Journals (Sweden)

    Jian Huan Su

    2014-08-01

    Full Text Available A practical active disturbance rejection control (ADRC solution is proposed for the furnace temperature system. Employing a linear reduced-order model with optimized parameters, the practical ADRC is simple to use, easy to tune and energy-efficient in dealing with the uncertainties and disturbances in plant dynamics. Through the order reduction in both the plant model and the state observer, we develop a first order extended state observer for estimating in real-time the total value of the external and internal disturbances. The practical and standard ADRCs outperform the Smith Predictor and the PID controller in disturbance-rejection and robustness; however, the practical ADRC has fewer adjustable parameters and significantly smaller energy consumption than the standard ADRC, making it a viable candidate for industrial applications.

  20. On the centrality of disturbance rejection in automatic control.

    Science.gov (United States)

    Gao, Zhiqiang

    2014-07-01

    In this paper, it is shown that the problem of automatic control is, in essence, that of disturbance rejection, with the notion of disturbance generalized to symbolize the uncertainties, both internal and external to the plant. A novel, unifying concept of disturbance rejector is proposed to compliment the traditional notion of controller. The new controller-rejector pair is shown to be a powerful organizing principle in the realm of automatic control, leading to a Copernican moment where the model-centric design philosophy is replaced by the one that is control-centric in the following sense: the controller is designed for a canonical model and is fixed; the difference between the plant and the canonical model is deemed as disturbance and rejected. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Active disturbance rejection in large flexible space structures

    Science.gov (United States)

    Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    The design of an active control law for the rejection of persistent disturbances, in large space structures is presented. The control system design approach is based on a deterministic model of the disturbances and it optimizes the magnitude of the disturbance that the structure can tolerate without violating certain predetermined constraints. In addition to closed-loop stability, the explicit treatment of state, control, and control rate constraints, such as structural displacement and control actuator effort, guarantees that the final design will exhibit desired performance characteristics. The technique is applied to a simple two-bay truss structure, and its response is compared with that obtained using a linear-quadratic-Gaussian/loop-transfer-recovery (LQG/LTR) compensator. Preliminary results indicate that the proposed control system can reject persistent disturbances of greater magnitude by utilizing most of the available control, while limiting the structural displacements to within desired tolerances.

  2. Optimal periodic disturbance reduction for active noise cancelation

    Science.gov (United States)

    Kinney, C. E.; de Callafon, R. A.; Dunens, E.; Bargerhuff, R.; Bash, C. E.

    2007-08-01

    The design of an optimal internal model-based (IMB) controller by extending standard discrete time optimal control theory for IMB controllers is described. The optimal observer and state feedback gains of the IMB controller are given via the solution of discrete time algebraic Riccati equations. The design method is applied to an acoustic system that is subjected to disturbances from a server fan. Periodic disturbances from the server fan appear as harmonics of the fundamental frequency of the fan. Parametric models for the plant and non-periodic part of the disturbance are identified from experimental data. An internal model is designed in discrete time and the internal model principle is used to design a feedback controller that rejects periodic disturbances in the acoustic system. The controller is implemented in real-time and successfully attenuates the first four harmonics of the fan noise.

  3. Active disturbance rejection control in steering by wire haptic systems.

    Science.gov (United States)

    Rodriguez-Angeles, A; Garcia-Antonio, J A

    2014-07-01

    This paper introduces a steering by wired haptic system based on disturbance rejection control techniques. High gain Generalized Proportional Integral (GPI) observers are considered for the estimation of tire and steering wheel dynamic disturbances. These disturbances are on line canceled to ensure tracking between the commanded steering wheel angle and the tire orientation angle. The estimated disturbances at the steering rack are feedback to the steering wheel to provide a haptic interface with the driver. The overall system behaves as a bilateral master-slave system. Very few sensors and minimum knowledge of the dynamic model are required. Experimental results are presented on a prototype platform that consists on: (1) half of the steering rack of a beetle VW vehicle, (2) a steering wheel. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Sleep disturbances in veterans with chronic war-induced PTSD

    National Research Council Canada - National Science Library

    Khazaie, Habibolah; Ghadami, Mohammad Rasoul; Masoudi, Maryam

    2016-01-01

    ..., as well as sleep disorders. Although the majority of studies reveal the association between PTSD and sleep disturbances, there are few studies on the assessment of sleep disruption among veterans with PTSD...

  5. Self-regulation strategies of children with emotional disturbance.

    Science.gov (United States)

    Barnes, Karin J; Vogel, Kimberly A; Beck, Alison J; Schoenfeld, Heidi B; Owen, Steven V

    2008-01-01

    Children with emotional disturbance frequently have difficulty regulating their classroom behaviors. Many have co-occurrence of other disabilities, such as sensory processing problems, which compound difficulties in school participation. This exploratory project evaluated the 8-week-long use of the Alert Program within the classroom setting for seven children with emotional disturbance. Five children with emotional disturbance served as a control group. Self-regulation, behavioral adjustments, and sensory processing skills as reported by the children and teachers were evaluated. Changes from pretest to posttest indicated that children who received the Alert Program demonstrated a small improvement on all measures while performance of the control group remained relatively constant or decreased. These preliminary results indicate programs that target self-regulation skills may be useful in helping to improve self-regulation of children with emotional disturbance.

  6. Wildlife use of disturbed habitats in arctic Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In summer 1989, BP Exploration (Alaska) Inc. (BPX) and LGL Alaska Research Associates, Inc. (LGL) initiated a study of wildlife use of disturbed habitats in arctic...

  7. Clinical observation of taste disturbance induced by radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Yuzuru; Sera, Koshi; Nagasawa, Hiroshi; Fukushima, Noriyuki; Yajin, Koji; Harada, Yasuo (Hiroshima Univ. (Japan). School of Medicine)

    1984-02-01

    Qualitative gustometry (filter paper disc method) was performed in six patients who underwent radiation therapy. Following results were obtained. 1) Subjective taste disturbance appeared when irradiation dosage amounted to 1000-2000 rad. Whereas, it disappeared in 1 to 3 months after the termination of irradiation. 2) The longer the period of irradiation, the more slowly taste disturbance recovered. 3) Disgeusia was noticed in 44.3% of S, 66.7% of N, 70% of T and 36.2% of Q tests. 4) Taste thresholds in the apical tongue region improved almost parallel to subjective recovery of the taste. Occasionally taste disturbance was prolonged over a month. This is possibly due to delayed regeneration of the gustatory buds. Furthermore, conditions of the oral cavity, such as infection, or mechanical stimulation, may well influence degree of taste disturbance and the process of regeneration.

  8. Minimum disturbance rewards with maximum possible classical correlations

    Energy Technology Data Exchange (ETDEWEB)

    Pande, Varad R., E-mail: varad_pande@yahoo.in [Department of Physics, Indian Institute of Science Education and Research Pune, 411008 (India); Shaji, Anil [School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, 695016 (India)

    2017-07-12

    Weak measurements done on a subsystem of a bipartite system having both classical and nonClassical correlations between its components can potentially reveal information about the other subsystem with minimal disturbance to the overall state. We use weak quantum discord and the fidelity between the initial bipartite state and the state after measurement to construct a cost function that accounts for both the amount of information revealed about the other system as well as the disturbance to the overall state. We investigate the behaviour of the cost function for families of two qubit states and show that there is an optimal choice that can be made for the strength of the weak measurement. - Highlights: • Weak measurements done on one part of a bipartite system with controlled strength. • Weak quantum discord & fidelity used to quantify all correlations and disturbance. • Cost function to probe the tradeoff between extracted correlations and disturbance. • Optimal measurement strength for maximum extraction of classical correlations.

  9. The ecological disturbance caused by fishing in the North Sea

    NARCIS (Netherlands)

    Greenstreet, S.P.R.; Robinson, L.; Piet, G.J.; Craeymeersch, J.A.M.; Callaway, R.

    2007-01-01

    Current knowledge of the ecological disturbance caused by fishing to marine fish and benthic invertebrate communities is reviewed. This review considers the various components of mortality caused by fishing (eg landings, discards, trawl escapees, etc) and examines the information currently

  10. Sleep Disturbance, Inflammation and Depression Risk in Cancer Survivors

    Science.gov (United States)

    Irwin, Michael R.; Olmstead, Richard E.; Ganz, Patricia A.; Haque, Reina

    2012-01-01

    Over two-thirds of the 11.4 million cancer survivors in the United States can expect long-term survival, with many others living with cancer as a chronic disease controlled by ongoing therapy. However, behavioral co-morbidities often arise during treatment and persist long-term to complicate survival and reduce quality of life. In this review, the inter-relationships between cancer, depression, and sleep disturbance are described, with a focus on the role of sleep disturbance as a risk factor for depression. Increasing evidence also links alterations in inflammatory biology dynamics to these long-term effects of cancer diagnosis and treatment, and the hypothesis that sleep disturbance drives inflammation, which together contribute to depression, is discussed. Better understanding of the associations between inflammation and behavioral co-morbidities has the potential to refine prediction of risk and development of strategies for the prevention and treatment of sleep disturbance and depression in cancer survivors. PMID:22634367

  11. Reality Therapy with Institutionalized Emotionally Disturbed Mentally Retarded Adolescents.

    Science.gov (United States)

    Dolly, John P.; Page, D. Patricia

    1981-01-01

    The study evaluated a reality therapy program used with 20 institutionalized mentally retarded (mild to profound) and emotionally disturbed adolescents residing in an institution. Results indicated that 17 of the Ss increased adaptive behaviors and all decreased maladaptive behaviors. (DB)

  12. Disturbance observer based hierarchical control of coaxial-rotor UAV.

    Science.gov (United States)

    Mokhtari, M Rida; Cherki, Brahim; Braham, Amal Choukchou

    2017-03-01

    This paper propose an hierarchical controller based on a new disturbance observer with finite time convergence (FTDO) to solve the path tracking of a small coaxial-rotor-typs Unmanned Aerial Vehicles (UAVs) despite of unknown aerodynamic efforts. The hierarchical control technique is used to separate the flight control problem into an inner loop that controls attitude and an outer loop that controls the thrust force acting on the vehicle. The new disturbance observer with finite time convergence is intergated to online estimate the unknown uncertainties and disturbances and to actively compensate them in finite time.The analysis further extends to the design of a control law that takes the disturbance estimation procedure into account. Numerical simulations are carried out to demonstrate the efficiency of the proposed control strategy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation

    Science.gov (United States)

    Irwin, Michael R.; Olmstead, Richard; Carroll, Judith E.

    2015-01-01

    Background Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans. Methods A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation, and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model. Results A total of 72 studies (n>50000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNF). Sleep disturbance was associated with higher levels of CRP (ES 0.12; 95% CI 0.05 – 0.19) and IL-6 (ES 0.20; 95% CI 0.08 – 0.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES 0.09; 95% CI 0.01 – 0.17) but not IL-6 (ES 0.03; 95% CI −0.09 – 0.14). The extreme of long sleep duration was associated with higher levels of CRP (ES 0.17; 95% CI 0.01 – 0.34) and IL-6 (ES 0.11; 95% CI 0.02 – 0.20). Neither sleep disturbances nor sleep duration was associated with TNF. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNF. Some heterogeneity among studies was found, but no evidence of publication bias. Conclusions Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation. PMID:26140821

  14. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation.

    Science.gov (United States)

    Irwin, Michael R; Olmstead, Richard; Carroll, Judith E

    2016-07-01

    Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans. A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model. A total of 72 studies (n > 50,000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα). Sleep disturbance was associated with higher levels of CRP (ES .12; 95% CI = .05-.19) and IL-6 (ES .20; 95% CI = .08-.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES .09; 95% CI = .01-.17) but not IL-6 (ES .03; 95% CI: -.09 to .14). The extreme of long sleep duration was associated with higher levels of CRP (ES .17; 95% CI = .01-.34) and IL-6 (ES .11; 95% CI = .02-20). Neither sleep disturbances nor sleep duration was associated with TNFα. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNFα. Some heterogeneity among studies was found, but there was no evidence of publication bias. Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  15. Disturbed tryptophan metabolism in cardiovascular disease.

    Science.gov (United States)

    Mangge, H; Stelzer, I; Reininghaus, E Z; Weghuber, D; Postolache, T T; Fuchs, D

    2014-06-01

    cardiovascular morbidity and mortality. Accelerated catabolism of TRP is further involved in the pathogenesis of the anemia of scLGI. The pro-inflammatory cytokine IFN-γ suppresses growth and differentiation of erythroid progenitor cells, and the depletion of TRP limits protein synthesis and thus hemoglobin production, and, through reduction in oxygen supply, may contribute to ischemic vascular disease. In this review we discuss the impact of TRP breakdown and the related complex mechanisms on the prognosis and individual course of CVD. Measurement of TRP, KYN concentrations, and calculation of the KYN/TRYP ratio will contribute to a better understanding of the interplay between inflammation, metabolic syndrome, mood disturbance, and anemia, all previously described as significant predictors of an unfavorable outcome in patients with CVD. The review leads to a novel framework for successful therapeutic modification of several cardinal pathophysiological processes leading to adverse cardiovascular outcome.

  16. Chronic Sleep Disturbance Impairs Glucose Homeostasis in Rats

    OpenAIRE

    R. Paulien Barf; Peter Meerlo; Scheurink, Anton J. W.

    2010-01-01

    Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory conditions. Three groups of animals were used: a sleep restriction group (RS), a group subjected to moderate sleep disturbance without restriction of sleep time (DS), and a home cage control group. To e...

  17. Sleep Disturbance in Bipolar Disorder Across the Lifespan

    OpenAIRE

    Harvey, Allison G.; Talbot, Lisa S.; Gershon, Anda

    2009-01-01

    The aim of this article is to highlight the importance of the sleep–wake cycle in children, adolescents, and adults with bipolar disorder. After reviewing the evidence that has accrued to date on the nature and severity of the sleep disturbance experienced, we document the importance of sleep for quality of life, risk for relapse, affective functioning, cognitive functioning, health (sleep disturbance is implicated in obesity, poor diet, and inadequate exercise), impulsivity, and risk taking....

  18. Features of sleep disturbances in multiple sclerosis patients.

    Science.gov (United States)

    Leonavicius, Rytis; Adomaitiene, Virginija

    2014-09-01

    Sleep disturbances in multiple sclerosis (MS) have received little research attention despite the potential influence it may have on the impact of the disease. The aim of this study was to evaluate the prevalence of sleep disturbances in a Lithuanian community sample of individuals with the relapsing remitting multiple sclerosis (RRMS) and its relation with depression, anxiety, and health related quality of life (HRQoL). The examined group consisted of 137 RRMS outpatients. The following questionnaires were used: the original socio-demographic questionnaire, Medical Outcomes Study Sleep (MOSS) measure, Hospital Anxiety and Depression Scale (HADS), and HRQoL measure. The relationship of objective sleep disturbances was evaluated with multivariate linear regression, adjusted to socio-demographic and clinical data. Sleep disturbances were present in 45.3 percent of patients. According to the HADS-D, depressive symptoms were present in 21.9 percent, according to the HADS-A, anxiety symptoms were present in 19.7 percent of study participants. Mean value of Physical and Mental component of HRQoL respectively constituted 40.4 and 44.5. We observed the relationship between sleep disturbances and gender, age, EDSS, prevalence of depression and anxiety, and Physical and Mental component of HRQoL. Our research was limited by narrow number of study participants and could be accepted only as preliminary study. The study investigated only RRMS patients, therefore investigation of other clinical forms of MS could provide more exhaustive data related with sleep disturbances. The investigation included only outpatients group, therefore research of inpatients could provide more comprehensive data. Sleep disturbances in our study were common in RRMS, and they related with female gender, older age, higher disability status, prevalence of depression and anxiety, and worse HRQoL. The treatable causes of sleep disturbances in RRMS should be identified and cured. However, further research

  19. The Effect of Sleep Disturbances on Major Depressive Disorder

    OpenAIRE

    Pigeon, Wilfred R.

    2009-01-01

    Sleep disturbances not only commonly occur in major depressive disorder, but constitute one of the symptom criteria. Importantly, there is growing inference that sleep disturbances may be more than a symptomatic byproduct of depression; poor sleep may play a role in the development or clinical course of depression, or both. This article reviews the prevalence of the two major classes of sleep disorders, the insomnias and the sleep-disordered breathing disorders, as they pertain to depression....

  20. Reconstructing Disturbances and Their Biogeochemical Consequences over Multiple Timescales

    OpenAIRE

    McLauchlan, Kendra K.; Philip E. Higuera; Gavin, Daniel G.; Perakis, Steven S; Mack, Michelle C.; Alexander, Heather; Battles, John, J.; Biondi, Franco; Buma, Brian; Colombaroli, Daniele; Enders, Sara K.; Engstrom, Daniel R.; Hu, Feng Sheng; Marlon, Jennifer R.; Marshall, John

    2017-01-01

    Ongoing changes in disturbance regimes are predicted to cause acute changes in ecosystem structure and function in the coming decades, but many aspects of these predictions are uncertain. A key challenge is to improve the predictability of postdisturbance biogeochemical trajectories at the ecosystem level. Ecosystem ecologists and paleoecologists have generated complementary data sets about disturbance (type, severity, frequency) and ecosystem response (net primary productivity, nutrient cycl...

  1. Random tensors

    CERN Document Server

    Gurau, Razvan

    2017-01-01

    Written by the creator of the modern theory of random tensors, this book is the first self-contained introductory text to this rapidly developing theory. Starting from notions familiar to the average researcher or PhD student in mathematical or theoretical physics, the book presents in detail the theory and its applications to physics. The recent detections of the Higgs boson at the LHC and gravitational waves at LIGO mark new milestones in Physics confirming long standing predictions of Quantum Field Theory and General Relativity. These two experimental results only reinforce today the need to find an underlying common framework of the two: the elusive theory of Quantum Gravity. Over the past thirty years, several alternatives have been proposed as theories of Quantum Gravity, chief among them String Theory. While these theories are yet to be tested experimentally, key lessons have already been learned. Whatever the theory of Quantum Gravity may be, it must incorporate random geometry in one form or another....

  2. Alterations in geochemical associations in artificially disturbed deep-sea sediments

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Parthiban, G.; Banaulikar, S.; Sarkar, S.

    'benthic disturber' were studied for metal variation in three phases: (1) before the disturbance, (2) immediately after the disturbance, and (3) during monitoring of restoration after approx. 44 months, from the same locations. Minor variations in metal...

  3. The Effects of Large Disturbances on On-Line Reinforcement Learning for aWalking Robot

    NARCIS (Netherlands)

    Schuitema, E.; Caarls, W.; Wisse, M.; Jonker, P.P.; Babuska, R.

    2010-01-01

    Reinforcement Learning is a promising paradigm for adding learning capabilities to humanoid robots. One of the difficulties of the real world is the presence of disturbances. In Reinforcement Learning, disturbances are typically dealt with stochastically. However, large and infrequent disturbances

  4. Respiratory Disturbances in Rett Syndrome: Don't Forget to Evaluate Upper Airway Obstruction

    NARCIS (Netherlands)

    Hagebeuk, Eveline E. O.; Bijlmer, Rob P. G. M.; Koelman, Johannes H. T. M.; Poll-The, Bwee Tien

    2012-01-01

    Rett syndrome is characterized by loss of motor and social functions, development of stereotypic hand movements, seizures, and breathing disturbances. This study evaluates the presence of overnight respiratory disturbances. Polysomnography in combination with a questionnaire (the Sleep Disturbance

  5. Random functions and turbulence

    CERN Document Server

    Panchev, S

    1971-01-01

    International Series of Monographs in Natural Philosophy, Volume 32: Random Functions and Turbulence focuses on the use of random functions as mathematical methods. The manuscript first offers information on the elements of the theory of random functions. Topics include determination of statistical moments by characteristic functions; functional transformations of random variables; multidimensional random variables with spherical symmetry; and random variables and distribution functions. The book then discusses random processes and random fields, including stationarity and ergodicity of random

  6. Left-handedness and neurotic disturbances in adult urban population.

    Science.gov (United States)

    Milenković, Sanja; Brkić, Milica; Belojević, Goran

    2013-01-01

    Controversial results on the relationship between the left-handedness and neurotic disturbances have been obtained in so far investigations. The aim of this study was to investigate the link between the left-handedness and neurotic disturbances in an adult urban population. A cross-sectional study was performed on 1,202 adult residents of the Stari Grad municipality in Belgrade, out of which 401 were males (33.4%) and 801 were females (66.6%). A questionnaire was used as an investigation instrument, with questions concerning age, gender, writing hand and neurotic disturbances: tension, agressiveness, anger, nervousness, weepiness and seclusion. Left-handedness was found in 60 subjects (5%) and it was statistically more frequent in males (7.7%) compared to females (3.6%) (p = 0.003). A decreasing trend of proportion of left-handed males was found in relation to aging. In the age group 18 to 39 years, agressiveness, as a specific neurotic disturbance, was significantly more frequent in left-handed males in comparison to right-handers (p = 0.035). In the age group 40 to 59 years, neurotic disturbances were more common among left-handed males compared to right-handers (p = 0.030).There were no significant diferences in the proportion of neurotic disturbances between the left-handed and the right-handed females. From a public health point of view, left-handed men may be regarded as a relatively vulnerable population category concerning mental health.

  7. Disturbances of Attachment and Parental Psychopathology in Early Childhood

    Science.gov (United States)

    Schechter, Daniel S.; Willheim, Erica

    2009-01-01

    Synopsis As the field of attachment has expanded over the past four decades, the perturbations in the relational context which give rise to disturbances of attachment are increasingly, though by no means conclusively, understood. In Part I, this article reviews the historical and current state of research regarding normative attachment classification, the diagnosis of Reactive Attachment Disorder, and the proposed categories of Secure Base Distortions and Disrupted Attachment Disorder. In Part II, the article explores the role of parental psychopathology and the manner in which disturbed caregiver self-regulation leads to disturbances in the mutual regulation between caregiver and infant. The question of the relationship between particular types of maternal pathology and particular forms of attachment disturbance is examined through recent research on the association between maternal PTSD, Atypical Maternal Behavior, and child scores on the Disturbances of Attachment Interview (DAI). The authors present original research findings to support that the presence and severity of maternal violence-related PTSD were significantly associated with secure base distortion in a community pediatrics sample of 76 mothers and preschool-age children. Clinical implications and recommendations for treatment of attachment disturbances conclude the article. PMID:19486844

  8. Nurses' management of adolescent sleep disturbance: a qualitative study.

    Science.gov (United States)

    Vallido, Tamara; Jackson, Debra; O'Brien, Louise

    2010-02-01

    To evaluate nurses' knowledge of adolescent sleep and sleep disturbance and the strategies they employ to facilitate sleep in adolescent patients. Sleep disturbance in adolescents is common and associated with potentially devastating outcomes and co-morbidities. Despite this, little literature exists that reports nursing interventions related to facilitating sleep, and no literature could be located that explored what Australian nurses know about adolescent sleep and sleep disturbance. Qualitative. Eight nurses routinely involved in the care of adolescent patients were interviewed via email and instant messaging over a five month period. Explored was the formation and extent of knowledge held by these nurses about adolescent sleep and sleep disturbance and the strategies they used to facilitate sleep in adolescent patients. Data were analysed thematically. Three main themes were identified: 'A patchwork of experiences', 'Traditional remedies, personal beliefs and commonsense' and 'Drugs, doctors and disempowerment'. Despite a lack of formal education about adolescent sleep and sleep disturbance, through life and professional experience the nurses in this study had formulated effective strategies to assist the sleep of adolescent patients. RELEVANCE TO CLINICAL PRACTICE; There is a need for nursing education regarding adolescent sleep issues. Providing rationales for nursing strategies would afford nurses greater confidence to strongly advocate for a more non-pharmacological approach to managing certain types of sleep disturbance. Initiating routine assessment of adolescent sleep in both hospital and community settings could be beneficial to detecting a range of difficulties adolescent patients may be experiencing.

  9. Sleep and wake disturbances following traumatic brain injury.

    Science.gov (United States)

    Duclos, C; Dumont, M; Wiseman-Hakes, C; Arbour, C; Mongrain, V; Gaudreault, P-O; Khoury, S; Lavigne, G; Desautels, A; Gosselin, N

    2014-10-01

    Traumatic brain injury (TBI) is a major health concern in industrialised countries. Sleep and wake disturbances are among the most persistent and disabling sequelae after TBI. Yet, despite the widespread complaints of post-TBI sleep and wake disturbances, studies on their etiology, pathophysiology, and treatments remain inconclusive. This narrative review aims to summarise the current state of knowledge regarding the nature of sleep and wake disturbances following TBI, both subjective and objective, spanning all levels of severity and phases post-injury. A second goal is to outline the various causes of post-TBI sleep-wake disturbances. Globally, although sleep-wake complaints are reported in all studies and across all levels of severity, consensus regarding the objective nature of these disturbances is not unanimous and varies widely across studies. In order to optimise recovery in TBI survivors, further studies are required to shed light on the complexity and heterogeneity of post-TBI sleep and wake disturbances, and to fully grasp the best timing and approach for intervention. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. Calculated disturbances for evaluation of dynamical properties of freight cars

    Directory of Open Access Journals (Sweden)

    I.A. Mashchenko

    2013-08-01

    Full Text Available Purpose. To form realizations of the calculated disturbances for studying the dynamic properties of railway vehicles. Methodology. Records of the track-test car for one of the typical track sections of the Pridneprovsk railroad are the basic data for building the disturbance components. To derive the true geometric parameters of the railway gauge the records of the track-test car using a double-point metering circuit are transformed considering the transfer function of the measuring system. A model of the calculated disturbances is presented as the four components: a symmetric vertical irregularity determined as a semi-sum of vertical irregularities of the right and left rails; an oblique-symmetric vertical irregularity of the track determined as a semi-difference of vertical irregularities of the right and left rails; horizontal irregularities of the right and left rails. Acceptability criterion of the constructed disturbances is a relationship between the values of the dynamical properties factors of cars and the corresponding experimental data. Findings. The three techniques for the calculated disturbances forming are proposed. The first technique uses records of the track-test car for the track with a sufficiently high amount for given track conditions as components of the calculated disturbances. In so doing symmetrical vertical components of disturbances resulting from records of settling are corrected with the mass and stiffness parameters of the car under consideration. The second technique uses building and applying the theoretical realizations of irregularities corresponding to a real track according to a spectral analysis. The third technique ensures a polyharmonic model of disturbances, the parameters of which are the values of the basic frequencies and amplitudes that are typical for irregularities of a railway track. A possibility of practical applying of the constructed models of disturbances are presented using an example for

  11. An interactive training programme to treat body image disturbance.

    Science.gov (United States)

    Gledhill, Lucinda J; Cornelissen, Katri K; Cornelissen, Piers L; Penton-Voak, Ian S; Munafò, Marcus R; Tovée, Martin J

    2017-02-01

    Anorexia nervosa (AN) is a life-threatening mental health condition. A core feature is a disturbance of body image, such that sufferers see themselves as fatter than they actually are. We tested the effectiveness of a novel training programme to recalibrate our participants' perception of body size. In a novel adaptation of a cognitive bias training programme, participants judged the body size of a series of female bodies and were given feedback to improve their accuracy over four daily training sessions. In Study 1, we recruited young women with high concerns about their body size for a randomized controlled study. In Study 2, we then applied the training programme to a case series of women with atypical AN. In Study 1, the training programme significantly improved the body size judgements of women with high body concerns compared to controls. We also found evidence of improved body image and reduced eating concerns in this group. In Study 2, the programme again recalibrated the body size judgements of women with atypical AN. We also saw evidence of a clinically meaningful reduction in their body size and eating-disordered concerns. This training has the potential to be a valuable treatment used together with more traditional talking therapies. Statement of contribution What is already known on this subject? A core feature of anorexia nervosa (AN) is an overestimation of body size; sufferers believe themselves to be larger than they are in reality. This study shows that an individual's perceptual boundary between what they classify as a fat versus a thin body is not immutable; it can be changed through a cognitive bias training programme. What does this study add? This means that body size overestimation may now be treatable. Critically, as well as improving the accuracy of body size judgements, we also found a clinically significant improvement in participants' eating-disordered concerns. This demonstrates that a targeted behavioural training regime can change

  12. Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing.

    Science.gov (United States)

    Kessel, Line; Siganos, Galatios; Jørgensen, Torben; Larsen, Michael

    2011-09-01

    Sleep pattern and circadian rhythms are regulated via the retinohypothalamic tract in response to stimulation of a subset of retinal ganglion cells, predominantly by blue light (450-490 nm). With age, the transmission of blue light to the retina is reduced because of the aging process of the human lens, and this may impair the photoentrainment of circadian rhythm leading to sleep disorders. The aim of the study was to examine the association between lens aging and sleep disorders. Cross-sectional population based study. The study was performed at the Research Center for Prevention and Health, Glostrup Hospital, Denmark and at the Department of Ophthalmology, Herlev Hospital, Denmark. An age- and sex-stratified sample of 970 persons aged 30 to 60 years of age drawn from a sample randomly selected from the background population. Not applicable. Sleep disturbances were evaluated by a combination of questionnaire and the use of prescription sleeping medication. Lens aging (transmission and yellowing) was measured objectively by lens autofluorometry. The risk of sleep disturbances was significantly increased when the transmission of blue light to the retina was low, even after correction for the effect of age and other confounding factors such as smoking habits, diabetes mellitus, gender, and the risk of ischemic heart disease (P blue light by the aging lens was significantly associated with an increased risk of sleep disturbances. We propose that this is a result of disturbance of photoentrainment of circadian rhythms.

  13. Road traffic noise: annoyance, sleep disturbance, and public health implications.

    Science.gov (United States)

    Kim, Minho; Chang, Seo I; Seong, Jeong C; Holt, James B; Park, Tae H; Ko, Joon H; Croft, Janet B

    2012-10-01

    The WHO has recognized environmental noise as harmful pollution that causes adverse psychosocial and physiologic effects (i.e., annoyance and sleep disturbance) on human health. In Europe, noise-related health studies have been actively conducted, but the U.S. has lagged behind in this research field. This research predicted ambient levels of road traffic noise for a highly urbanized area: Fulton County GA. Assessment was made of noise impacts on the population, focusing on annoyance and sleep disturbance. All the data sets were collected during 2009-2011, and data analysis was performed in 2010-2011. The study used a sound-propagation model for noise-level prediction and derived noise-impact indicators for annoyance and sleep disturbance from exposure-response models. Then, annoyed and sleep-disturbed populations were predicted with the use of each noise-impact indicator. It was predicted that 109,967 people would be at risk of being highly annoyed, with 19,621 people at risk for high sleep disturbance for Fulton County GA. Noise-impact indicators such as the percentage of those who were highly annoyed and who had high levels of sleep disturbance were expected to be valuable metrics to compare noise equity among urban communities. Many residents of the greater Atlanta area may be exposed to noise levels that put them at risk of being highly annoyed or having high levels of sleep disturbance. These results, if generalized to other urban areas with high levels of road traffic, indicate that it may be important for the public's health to update existing noise-related policies or develop new ones to control and abate noise concerns in urban communities. Published by Elsevier Inc.

  14. Sleep disturbance experiences among perimenopausal women in Taiwan.

    Science.gov (United States)

    Hsu, Hsiu-Chin; Chen, Ning-Hung; Jou, Hei-Jen; An, Chi; Tsao, Lee-Ing

    2009-08-01

    To generate a descriptive theory framework regarding the experiences of sleep disturbances among perimenopausal women in Taiwan. Although studies show that some perimenopausal women are troubled by sleep problems, little information was found about the subjective experiences of sleep disturbances among these women. Research is required to explore women's feelings or perceptions in dealing with their sleep problems. These understandings will be important to help alleviate perimenopausal women's sleep problems. A grounded theory research design was applied. Twenty-one Taiwanese sleep disturbed women, aged 46-57 years, participated in in-depth interviews. 'Getting back a good night's sleep' was the core theme for describing and guiding the process of the women's sleep disturbance experiences. During the process, 'disturbed sleep' was identified as the antecedent condition that included subcategories: easy awakening, difficulty falling asleep, inner worries, physical discomfort and genetic and bodily constitution. Analyses showed five categories (some with subcategories) of the sleep disturbed women: (i) worsening health status - physical exhaustion, impaired social interactions, emotional swings and decreased work performance; (ii) living with lonely nights - self-help and endurance; (iii) a search for resources to relieve sleep difficulties - doctor shopping, trying alternative therapies, exercising and seeking support; (iv) vicious cycle and (v) acceptance of insomnia. Women expected to relieve their sleep disturbance by finding comprehensive counselling or by their body constitution responding to treatment. Healthcare providers need to value women's individual concerns and subjective voices. Providers must seek out sleep counselling instead of simply prescribing drugs for their sleep difficulties. It is crucial to integrate perimenopausal sleep care by implementing a multidimensional approach such as sleep assessment laboratories, sleep counselling, complementary

  15. Study on the complexity pricing game and coordination of the duopoly air conditioner market with disturbance demand

    Science.gov (United States)

    Ma, Junhai; Xie, Lei

    2016-03-01

    The paper focuses on the dynamic pricing game of the duopoly air conditioner market with disturbance in demand and analyzes the influence of disturbance on the dynamic game system. Considering the demand for products, such as air conditioner, varies with different seasons, we assume three cases based on the condition of disturbance, including growth market (Case 1), declining market (Case 2) and completely random market (Case 3). By analyzing these three cases and making comparison among them, the paper shows that the growth market is more sensitive to the changing parameters such as the adjustment variable and the competitive factor than the declining market. It is more difficult to keep the system stable in a growth market. Although the demand is completely random, the dynamic system can reach a stable state, on condition that the adjustment variable is small enough. The results also indicate that the bullwhip effect between the order quantity and the actual demand is weakened gradually along with the price adjustment.

  16. Wetland and aquatic macrophytes as indicators of anthropogenic hydrologic disturbance

    Science.gov (United States)

    Wilcox, Douglas A.

    1995-01-01

    Hydrologic disturbance can affect wetland and aquatic macrophyte communities by creating temporal changes in soil moisture or water depth. Such disturbances are natural and help maintain wetland diversity; however, anthropogenic changes in wetland hydrology may have negative effects on wetlands. Since plant communities respond to habitat alterations, observations of plant-community changes may be used to recognize effects of hydrologic disturbances that are otherwise not well understood. A number of plants, including Typha angustifolia (narrow-leaf cattail) and Lythrum salicaria (purple loosestrife), are recognized as disturbance species; they are often found in roadside ditches, in wetlands that have been partially drained, or in low areas that have been flooded. Other species commonly occur on mudflats exposed by lowering of water levels. In addition, wetland shrubs and trees invade or die as a result of draining or flooding. In more subtle terms, the relative composition of plant communities can change without the addition or loss of species, and zonation patterns may develop or change as a result of altered hydrology. Remote sensing (photointerpretation) and field vegetation studies, coupled with monitoring of water levels, are recommended for gaining an understanding of hydrologic disturbances in wetlands.

  17. Dynamic positioning system based on active disturbance rejection technology

    Science.gov (United States)

    Lei, Zhengling; Guo, Chen; Fan, Yunsheng

    2015-08-01

    A dynamically positioned vessel, by the International Maritime Organization (IMO) and the certifying class societies (DNV, ABS, LR, etc.), is defined as a vessel that maintains its position and heading (fixed location or pre-determined track) exclusively by means of active thrusters. The development of control technology promotes the upgrading of dynamic positioning (DP) systems. Today there are two different DP systems solutions available on the market: DP system based on PID regulator and that based on model-based control. Both systems have limited disturbance rejection capability due to their design principle. In this paper, a new DP system solution is proposed based on Active Disturbance Rejection Control (ADRC) technology. This technology is composed of Tracking-Differentiator (TD), Extended State Observer (ESO) and Nonlinear Feedback Combination. On one hand, both TD and ESO can act as filters and can be used in place of conventional filters; on the other hand, the total disturbance of the system can be estimated and compensated by ESO, which therefore enhances the system's disturbance rejection capability. This technology's advantages over other methods lie in two aspects: 1) This method itself can not only achieve control objectives but also filter noisy measurements without other specialized filters; 2) This method offers a new useful approach to suppress the ocean disturbance. The simulation results demonstrate the effectiveness of the proposed method.

  18. Quantifying the influence of oscillatory flow disturbances on blood flow.

    Science.gov (United States)

    Gabriel, Sargon A; Ding, Yan; Feng, Yuqing

    2017-10-07

    Pulsatile blood flow is renowned for inducing localised flow disturbances that are characterised by significant oscillations. These flow disturbances are recognised to have a physiologic significance within the cardiovascular system, particularly with respect to their proatherogenic expression on endothelial cells. Flow disturbances also impart significant influence on the mechanics of cardiovascular flow and are formally shown in the present study to be coupled to the period-average behaviour of a pulsatile flow field, causing it to be misrepresented by its steady-equivalent; which is often used in models of atherogenesis and hence limits their reliability. It is demonstrated that a measure of the localised influence of flow disturbances on the period-average flow can be realised by the relative significance of their kinetic energy, which is quantified by the introduced Oscillatory Kinetic Energy Index (OKEI). A specific measure of direction-reversing oscillations is also developed with the introduction of the Oscillatory Flow Index (OFI), which is an extension of the wall-bound Oscillatory Shear Index (OSI) onto flow and wall spaces. A case study of a human carotid artery is made; wherein pulsatile flow is studied relative to its steady-equivalent state. The introduced indices are demonstrated to collectively identify oscillatory flow disturbances within the flow; quantifying their spatial distribution and influence on the flow field. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Depressive symptoms and sleep disturbances in Korean American women

    Directory of Open Access Journals (Sweden)

    Eunjung Kim

    2017-01-01

    Full Text Available The purpose of this study was to examine the relationship between depressive symptoms and sleep disturbances among Korean American women. Forty-nine women completed the Center for Epidemiologic Studies Depression Scale, the Pittsburgh Sleep Quality Index, and revised Acculturation Rating Scale for Mexican Americans-II. Overall, participants scored 12.56 (SD = 9.93 on the Center for Epidemiologic Studies Depression Scale, 5.31 (SD = 3.01 on the Pittsburgh Sleep Quality Index, and -2.27 (SD = 1.64 on the Acculturation Rating Scale for Mexican Americans-II. Approximately 29% of the women (n = 14 scored 16 or higher on the Center for Epidemiologic Studies Depression Scale indicating that they had elevated depressive symptoms, and 39% (n = 19 scored 6 or higher on the Pittsburgh Sleep Quality Index, which indicated that they had sleep disturbances. Results from the stepwise multiple regression, controlling for the degree of the women’s acculturation, indicated that sleep disturbances (β = .39, p = .004 were significantly positively related to depressive symptoms, F(2, 46 = 7.27, p = .002 and the model explained 24% of the variance in women’s depressive symptoms. When taking care of Korean American women who have elevated depressive symptoms, their sleep disturbances need to be assessed. Health practitioners need to assess for depressive symptoms in women with sleep disturbances.

  20. [Non-Pharmacological Interventions for Pregnancy-Related Sleep Disturbances].

    Science.gov (United States)

    Hung, Hsuan-Man; Chiang, Hsiao-Ching

    2017-02-01

    Most women experience the worse sleep quality of their life during pregnancy and the early postpartum period. Although pregnancy typically accounts for a relatively short part of a woman's life, the related sleep disturbances may have a significant and negative impact on her long-term health. Approximately 78-80% of pregnant women experience sleep disturbances, including interruptions in deep sleep, decreased total sleep time, poor subjective sleep quality, frequent night waking, and reduced sleep efficacy. Sleep disturbances during pregnancy start during the first trimester and become prevalent during the third trimester. Related factors include physiological and psychosocial changes and an unhealthy lifestyle. As non-pharmacological interventions have the potential to improve sleep quality in 70% to 80% of patients with insomnia, this is the main approached that is currently used to treat pregnancy-related sleep disturbances. Examples of these non-pharmacological interventions include music therapy, aerobic exercise, massage, progressive muscle relaxation, multi-modal interventions, and the use of a maternity support belt. The efficacy and safety of other related non-pharmacological interventions such as auricular acupressure, cognitive therapy, tai chi, and aromatherapy remain uncertain, with more empirical research required. Additionally, non-pharmacological interventions do not effectively treat sleep disturbances in all pregnant women.

  1. Simulation of landscape disturbances and the effect of climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.L.

    1993-01-29

    The purpose of this research is to understand how changes in climate may affect the structure of landscapes that are subject to periodic disturbances. A general model useful for examining the linkage between climatic change and landscape change has been developed. The model makes use of synoptic climatic data, a geographical information system (GRASS), field data on the location of disturbance patches, simulation code written in the SIMSCRIPT language, and a set of landscape structure analysis programs written specifically for this research project. A simplified version of the model, lacking the climatic driver, has been used to analyze how changes in disturbance regimes (in this case settlement and fire suppression) affect landscape change. Landscape change lagged in its response to changes in the disturbance regime, but the lags differed depending upon the character of the change and the particular measure considered. The model will now be modified for use in a specific setting to analyze the effects of changes in climate on the structure of flood-disturbed patches along the Animas River, Colorado.

  2. Random fixed points and random differential inclusions

    Directory of Open Access Journals (Sweden)

    Nikolaos S. Papageorgiou

    1988-01-01

    Full Text Available In this paper, first, we study random best approximations to random sets, using fixed point techniques, obtaining this way stochastic analogues of earlier deterministic results by Browder-Petryshyn, KyFan and Reich. Then we prove two fixed point theorems for random multifunctions with stochastic domain that satisfy certain tangential conditions. Finally we consider a random differential inclusion with upper semicontinuous orientor field and establish the existence of random solutions.

  3. Adaptive Control for Revolute Joints Robot Manipulator with Uncertain/Unknown Dynamic Parameters and in Presence of Disturbance in Control Input

    DEFF Research Database (Denmark)

    Seyed Sakha, Masoud; Shaker, Hamid Reza

    2017-01-01

    This paper presents an effective adaptive controller for revolute joints robot manipulator where the control input is accompanied with a random disturbance (with unknown PSD). It is clear that, disturbance can compromise the overall performance of the system. To cope with this problem, a control...... technique is proposed which uses the concept of exponential practical stability. Unlike other counterparts, the proposed method does not need information such as the physical parameters of robot and gravitational acceleration. The results show that the proposed controller achieves an excellent performance...

  4. Correlates and Escitalopram Treatment Effects on Sleep Disturbance in Patients with Acute Coronary Syndrome: K-DEPACS and EsDEPACS

    Science.gov (United States)

    Kim, Jae-Min; Stewart, Robert; Bae, Kyung-Yeol; Kang, Hee-Ju; Kim, Sung-Wan; Shin, Il-Seon; Hong, Young Joon; Ahn, Youngkeun; Jeong, Myung Ho; Yoon, Jin-Sang

    2015-01-01

    Study Objectives: To investigate the correlates of sleep disturbance and to assess escitalopram treatment effects of depression on sleep disturbance in patients with acute coronary syndrome (ACS). Design: A cross-sectional study in patients with ACS within 2 w post-ACS, and a 24-w double-blind controlled trial of escitalopram against placebo for patients with ACS who have comorbid depressive disorders. Setting: A university hospital in South Korea. Participants: There were 1,152 patients with ACS who were consecutively recruited. Of 446 patients with comorbid depressive disorders, 300 were randomized to the trial. Measurements and Results: Sleep disturbance was evaluated by the Leeds Sleep Evaluation Questionnaire. Demographic and clinical characteristics were assessed, including cardiovascular risk factors, current cardiac status, and depressive symptoms. Depressive symptoms were most strongly and consistently associated with sleep disturbance. In addition, older age, female sex, hypertension, and more severe ACS status were associated with certain aspects of sleep disturbance. Escitalopram was significantly superior to placebo for improving sleep disturbance over the 24-w treatment period. These effects were substantially explained by improvement in depressive symptoms. Conclusions: Depression screening is indicated in patients with acute coronary syndrome with sleep disturbance. Successful treatment of depression has beneficial effects on sleep outcomes in these patients. Clinical Trials Information: ClinicalTrial.gov identifier for the 24-w drug trial, NCT00419471. Citation: Kim JM, Stewart R, Bae KY, Kang HJ, Kim SW, Shin IS, Hong YJ, Ahn Y, Jeong MH, Yoon JS. Correlates and escitalopram treatment effects on sleep disturbance in patients with acute coronary syndrome: K-DEPACS and EsDEPACS. SLEEP 2015;38(7):1105–1111. PMID:25581916

  5. Arbuscular mycorrhizae of the palm Astrocaryum mexicanum in disturbed and undisturbed stands of a Mexican tropical forest.

    Science.gov (United States)

    Núñez-Castillo, O; Alvarez-Sánchez, F J

    2003-10-01

    Tropical forests are dynamic systems with extensive natural disturbance, gaps in the canopy being one of the most important types. Tree and branch fall are often the principal cause of natural disturbance. This research was done on adult individuals of a very abundant palm ( Astrocaryum mexicanum Liebm, Arecaceae), which is found in the understorey of the forest at Los Tuxtlas, Mexico. Percentages of colonization by arbuscular mycorrhizae were determined for individuals selected randomly from plots located both in gaps and under closed canopy. The highest percentages of total colonization, as well as those of hyphae and vesicles, were recorded for gaps. In forest with closed canopy, arbuscules had the highest percentages of colonization; on these sites the palm has been observed to grow less. The higher production of arbuscules may favour nutrient capture in this microenvironment, which is characterized by strong competition.

  6. Mood disturbance in adolescents screened by the Mood Disorder Questionnaire predicts poorer social adjustment.

    Science.gov (United States)

    Pan, Pei-Yin; Yeh, Chin-Bin

    2015-06-01

    Early-onset bipolar disorder is associated with a more severe illness course and poorer outcome. Its identification in adolescents may provide the opportunity for adequate intervention to improve global functioning and long-term prognosis. Thus, this study aimed to screen mood disturbance in a sample of high school students using Mood Disorder Questionnaire (MDQ) and follow up their adaptive functioning 1 year later. In the first year, adolescents aged 15-17 years old from a Taiwanese senior high school (N = 1,151) completed the Chinese version of MDQ, the Impulsiveness Scale, and a set of questions about risky behaviors. A subgroup of respondents (N = 184) picked randomly were interviewed to validate the diagnosis of bipolar disorder. In the second year, the Social Adjustment Inventory for Children and Adolescents was applied for the same sample of subjects for the measurement of their adaptive functions. The intraclass correlation coefficient and the Cronbach α coefficient of the MDQ were .68 and .61, respectively. MDQ score of at least 7 showed modest sensitivity (.57) and specificity (.64) for bipolar disorder. Higher MDQ score predicted risky behaviors in adolescents at baseline measurement. MDQ score was found significantly correlated with Impulsiveness Scale total score. In follow-up evaluation, participants with an MDQ score of ≥7 had poorer social adjustment. Our findings suggest that untreated mood disturbance among adolescents leads to impaired social adaptive functioning in the next year. The application of MDQ in adolescents may help clinicians in early intervention for their emotional disturbance. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  7. Spectral and spatial variability of undisturbed and disturbed grass under different view and illumination directions

    Science.gov (United States)

    Borel-Donohue, Christoph C.; Shivers, Sarah Wells; Conover, Damon

    2017-05-01

    It is well known that disturbed grass covered surfaces show variability with view and illumination conditions. A good example is a grass field in a soccer stadium that shows stripes indicating in which direction the grass was mowed. These spatial variations are due to a complex interplay of spectral characteristics of grass blades, density, their length and orientations. Viewing a grass surface from nadir or near horizontal directions results in observing different components. Views from a vertical direction show more variations due to reflections from the randomly oriented grass blades and their shadows. Views from near horizontal show a mixture of reflected and transmitted light from grass blades. An experiment was performed on a mowed grass surface which had paths of simulated heavy foot traffic laid down in different directions. High spatial resolution hyperspectral data cubes were taken by an imaging spectrometer covering the visible through near infrared over a period of time covering several hours. Ground truth grass reflectance spectra with a hand held spectrometer were obtained of undisturbed and disturbed areas. Close range images were taken of selected areas with a hand held camera which were then used to reconstruct the 3D geometry of the grass using structure-from-motion algorithms. Computer graphics rendering using raytracing of reconstructed and procedurally created grass surfaces were used to compute BRDF models. In this paper, we discuss differences between observed and simulated spectral and spatial variability. Based on the measurements and/or simulations, we derive simple spectral index methods to detect spatial disturbances and apply scattering models.

  8. Recovery of an isolated coral reef system following severe disturbance.

    Science.gov (United States)

    Gilmour, James P; Smith, Luke D; Heyward, Andrew J; Baird, Andrew H; Pratchett, Morgan S

    2013-04-05

    Coral reef recovery from major disturbance is hypothesized to depend on the arrival of propagules from nearby undisturbed reefs. Therefore, reefs isolated by distance or current patterns are thought to be highly vulnerable to catastrophic disturbance. We found that on an isolated reef system in north Western Australia, coral cover increased from 9% to 44% within 12 years of a coral bleaching event, despite a 94% reduction in larval supply for 6 years after the bleaching. The initial increase in coral cover was the result of high rates of growth and survival of remnant colonies, followed by a rapid increase in juvenile recruitment as colonies matured. We show that isolated reefs can recover from major disturbance, and that the benefits of their isolation from chronic anthropogenic pressures can outweigh the costs of limited connectivity.

  9. GMD Coupling to Power Systems and Disturbance Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bent, Russell Whitford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-24

    Presentation includes slides on Geomagnetic Disturbance: Ground Fields; Geomagnetic Disturbance: Coupling to Bulk Electric System; Geomagnetic Disturbance: Transformers; GMD Assessment Workflow (TPL-007-1); FERC order 830; Goals; SuperMag (1 min data) Nov. 20-21, 2003 Storm (DST = -422); Spherical Harmonics; Spherical Harmonics Nov. 20-21, 2003 Storm (DST = -422); DST vs HN0,0; Fluctuations vs. DST; Fluctuations; Conclusions and Next Steps; GMD Assessment Workflow (TPL-007-1); EMP E3 Coupling to Texas 2000 Bus Model; E3 Coupling Comparison (total GIC) Varying Ground Zero; E3 Coupling Comparison (total MVAR) Varying Ground Zero; E3 Coupling Comparison (GIC) at Peak Ground Zero; E3 Coupling Comparison (GIC) at Peak Ground Zero; and Conclusion.

  10. Testing the disturbed zone around a rigid inclusion in salt

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, M.K.; Borns, D.; Fredrich, J.; Holcomb, D.; Price, R.; Zeuch, D. [Sandia National Labs., Albuquerque, NM (United States); Dale, T.; Van Pelt, R.S. [INTERA, Inc., Austin, TX (United States)

    1996-12-01

    Deformational processes within a zone of rock surrounding excavations in salt result in alteration of the geophysical and hydrologic properties as compared to the undisturbed condition. The disturbed rock zone offers little resistance to fluid flow. It is hypothesized that rigid inclusions such as concrete seals will arrest and subsequently reverse the disturbance process and induce healing in the disturbed This experiment gathered in situ data that substantiates this hypothesis. A series of tests was conducted in a volume of rock surrounding concrete seals that were placed in a 1-m borehole approximately eight years ago. Fluid flow measurements, measurements of geophysical parameters of the surrounding rock and petrographic analyses on core samples were performed to characterize the rock. This paper presents the testing methodology and summarizes the data gathered from the field test program.

  11. Robust Adaptive PID Control of Robot Manipulator with Bounded Disturbances

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2013-01-01

    Full Text Available To solve the strong nonlinearity and coupling problems in robot manipulator control, two novel robust adaptive PID control schemes are proposed in this paper with known or unknown upper bound of the external disturbances. Invoking the two proposed controllers, the unknown bounded external disturbances can be compensated and the global asymptotical stability with respect to the manipulator positions and velocities is able to be guaranteed. As compared with the existing adaptive PD control methods, the designed control laws can enlarge the tolerable external disturbances, enhance the accuracy in finite-time trajectory tracking control, and improve the dynamic performance of the manipulator systems. The stability and convergence properties of the closed-loop system are analytically proved using Lyapunov stability theory and Barbalat’s lemma. Simulations are performed for a planner manipulator with two rotary degrees of freedom to illustrate the viability and the advantages of the proposed controllers.

  12. Increased sensitivity to climate change in disturbed ecosystems.

    Science.gov (United States)

    Kröel-Dulay, György; Ransijn, Johannes; Schmidt, Inger Kappel; Beier, Claus; De Angelis, Paolo; de Dato, Giovanbattista; Dukes, Jeffrey S; Emmett, Bridget; Estiarte, Marc; Garadnai, János; Kongstad, Jane; Kovács-Láng, Edit; Larsen, Klaus Steenberg; Liberati, Dario; Ogaya, Romà; Riis-Nielsen, Torben; Smith, Andrew R; Sowerby, Alwyn; Tietema, Albert; Penuelas, Josep

    2015-03-24

    Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports this relationship for the perturbation of climate change. Here we show that vegetation (abundance, species richness and species composition) across seven European shrublands is quite resistant to moderate experimental warming and drought, and responsiveness is associated with the dynamic state of the ecosystem, with recently disturbed sites responding to treatments. Furthermore, most of these responses are not rapid (2-5 years) but emerge over a longer term (7-14 years). These results suggest that successional state influences the sensitivity of ecosystems to climate change, and that ecosystems recovering from disturbances may be sensitive to even modest climatic changes. A research bias towards undisturbed ecosystems might thus lead to an underestimation of the impacts of climate change.

  13. Cardiac disturbances after pneumonectomy--the value of prophylactic digitalization.

    Science.gov (United States)

    Järvinen, A; Mattila, T; Appelqvist, P; Meurala, H; Mattila, S

    1978-01-01

    The incidence of postoperative cardiac disturbances and the value of prophylactic digitalization were studied retrospectively in 143 patients undergoing pneumonectomy for carcinoma of the lung. Cardiac arrhythmias occurred in 29% and tachycardia episodes in 30% of the patients. The incidence of myocardial infarction was 2%. Operative mortality was 4%. The cardiac disturbances developed more often after left than after right pneumonectomy. The age of the patients, a history of angina pectoris or hypertension did not markedly increase the incidence of cardiac disturbances, neither did operative factors, such as pericardiotomy, left atrial resection, major bleeding nor postoperative empyema. Prophylactic digitalization significantly reduced postoperative cardiac disorders, their frequency being 33% in the group of patients who received prophylactic digitalis compared with 65% in the group that did not.

  14. Stress and sleep disturbances in female college students.

    Science.gov (United States)

    Lee, Shih-Yu; Wuertz, Caroline; Rogers, Rebecca; Chen, Yu-Ping

    2013-11-01

    To describe the sleep characteristics and examine the associations among perceived stress, sleep disturbances, depressive symptoms, and physical symptoms among female college students. A total of 103 students completed a battery of questionnaires. The students experienced high stress during the school year. The majority of them slept less than 6 hours during weekdays and experienced moderate fatigue. High stress levels are associated with sleep disturbances, less nocturnal total sleep time, higher fatigue severity, and more depressive symptoms. Perceived stress and sleep disturbances are significant predictors for depressive symptoms and physical symptoms. Compared to the good sleepers, the poor sleepers reported more daytime sleepiness, depressive symptoms, and physical symptoms. Interventions to reduce stress and improve sleep are critically needed in college education.

  15. The Effect of Sleep Disturbances on Major Depressive Disorder.

    Science.gov (United States)

    Pigeon, Wilfred R

    Sleep disturbances not only commonly occur in major depressive disorder, but constitute one of the symptom criteria. Importantly, there is growing inference that sleep disturbances may be more than a symptomatic byproduct of depression; poor sleep may play a role in the development or clinical course of depression, or both. This article reviews the prevalence of the two major classes of sleep disorders, the insomnias and the sleep-disordered breathing disorders, as they pertain to depression. Beyond prevalence, the empirical evidence reviewed suggests that insomnia is a risk factor for depression and that obstructive sleep apnea (OSA) is highly associated with depression. Preliminary evidence indicates that OSA may also be a risk factor for this disorder. The implications of these findings for the treatment of sleep disturbances either prior to or in the context of depression are discussed.

  16. Sleep disturbances in Parkinson's disease patients and management options

    Directory of Open Access Journals (Sweden)

    Claassen DO

    2011-12-01

    Full Text Available Daniel O Claassen, Scott J KutscherDepartment of Neurology, Vanderbilt University, Nashville, TN, USAAbstract: Sleep disturbances are among the most common nonmotor complaints of patients with Parkinson's disease (PD, and can have a great impact on quality of life. These disturbances manifest in a variety of ways; for instance, insomnia, sleep fragmentation, and excessive daytime sleepiness. Sleep-related movement disorders such as restless legs syndrome and periodic leg movements may share a common pathophysiology, and occurrence of rapid eye movement behavior disorder may predate the onset of PD or other synucleinopathies by several years. Medications for PD can have a significant impact on sleep, representing a great challenge to the treating physician. Awareness of the complex relationship between PD and sleep disorders, as well as the varied way in which sleep disturbances appear, is imperative for successful long-term management.Keywords: sleep disorders, insomnia, restless legs syndrome, Parkinson disease, fatigue, REM behavior disorder

  17. Disturbed eating behaviours and associated psychographic characteristics of college students.

    Science.gov (United States)

    Quick, V M; Byrd-Bredbenner, C

    2013-07-01

    Young adulthood is a stressful transition period that may increase the risk for disturbed eating, especially for college students. The present study aimed to explore disturbed eating behaviours and a broad array of associated psychographic characteristics in a large, diverse sample of college students. College students (n = 2604; 58% white; 63% female) enrolled at three large, public US universities in 2009 and 2010 were recruited to take an online survey. The survey included reliable and valid disturbed eating behaviour and associated psychographic characteristic measures. Many participants engaged in disturbed eating practices. For example, one-quarter of women and one-fifth of men engaged in dietary restraint. One in seven reported regularly binge eating. One-third used inappropriate compensatory behaviours (self-induced vomiting, medicine misuse and excessive exercise) as a means for controlling weight and/or shape, with the rate of these behaviours reaching clinically significant levels for 4%, 3% and 5% of participants, respectively. Examination of psychographic characteristics revealed that one-fifth had moderate levels of depression and anxiety severity and almost half engaged in at least one obsessive-compulsive disorder type behaviour. Females felt under more pressure to attain the media physical appearance standard than males. The findings of the present study suggest that nutrition education interventions for college students may be needed to address disturbed eating behaviours and to provide guidance on how to seek professional help. The findings also suggest that it may be prudent for healthcare professionals to routinely screen college students for disturbed eating behaviours and offer interventions early when treatment is likely to be most effective. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  18. Global and local disturbances interact to modify seagrass palatability

    Science.gov (United States)

    Egea, Luis G.; Ortega, María J.; Hernández, Ignacio; Vergara, Juan J.; Brun, Fernando G.

    2017-01-01

    Global change, such as warming and ocean acidification, and local anthropogenic disturbances, such as eutrophication, can have profound impacts on marine organisms. However, we are far from being able to predict the outcome of multiple interacting disturbances on seagrass communities. Herbivores are key in determining plant community structure and the transfer of energy up the food web. Global and local disturbances may alter the ecological role of herbivory by modifying leaf palatability (i.e. leaf traits) and consequently, the feeding patterns of herbivores. This study evaluates the main and interactive effects of factors related to global change (i.e. elevated temperature, lower pH levels and associated ocean acidification) and local disturbance (i.e. eutrophication through ammonium enrichment) on a broad spectrum of leaf traits using the temperate seagrass Cymodocea nodosa, including structural, nutritional, biomechanical and chemical traits. The effect of these traits on the consumption rates of the generalist herbivore Paracentrotus lividus (purple sea urchin) is evaluated. The three disturbances of warming, low pH level and eutrophication, alone and in combination, increased the consumption rate of seagrass by modifying all leaf traits. Leaf nutritional quality, measured as nitrogen content, was positively correlated to consumption rate. In contrast, a negative correlation was found between feeding decisions by sea urchins and structural, biomechanical and chemical leaf traits. In addition, a notable accomplishment of this work is the identification of phenolic compounds not previously reported for C. nodosa. Our results suggest that global and local disturbances may trigger a major shift in the herbivory of seagrass communities, with important implications for the resilience of seagrass ecosystems. PMID:28813506

  19. Pervasive growth reduction in Norway spruce forests following wind disturbance.

    Directory of Open Access Journals (Sweden)

    Rupert Seidl

    Full Text Available BACKGROUND: In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of disturbance impacts and ecosystem responses is needed. With regard to the effects of strong winds--the most detrimental disturbance agent in Europe--monitoring and management has focused on structural damage, i.e., tree mortality from uprooting and stem breakage. Effects on the functioning of trees surviving the storm (e.g., their productivity and allocation have been rarely accounted for to date. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that growth reduction was significant and pervasive in a 6.79 million hectare forest landscape in southern Sweden following the storm Gudrun (January 2005. Wind-related growth reduction in Norway spruce (Picea abies (L. Karst. forests surviving the storm exceeded 10% in the worst hit regions, and was closely related to maximum gust wind speed (R(2 = 0.849 and structural wind damage (R(2 = 0.782. At the landscape scale, wind-related growth reduction amounted to 3.0 million m(3 in the three years following Gudrun. It thus exceeds secondary damage from bark beetles after Gudrun as well as the long-term average storm damage from uprooting and stem breakage in Sweden. CONCLUSIONS/SIGNIFICANCE: We conclude that the impact of strong winds on forest ecosystems is not limited to the immediately visible area of structural damage, and call for a broader consideration of disturbance effects on ecosystem structure and functioning in the context of forest management and climate change mitigation.

  20. Sleep disturbances as an evidence-based suicide risk factor.

    Science.gov (United States)

    Bernert, Rebecca A; Kim, Joanne S; Iwata, Naomi G; Perlis, Michael L

    2015-03-01

    Increasing research indicates that sleep disturbances may confer increased risk for suicidal behaviors, including suicidal ideation, suicide attempts, and death by suicide. Despite increased investigation, a number of methodological problems present important limitations to the validity and generalizability of findings in this area, which warrant additional focus. To evaluate and delineate sleep disturbances as an evidence-based suicide risk factor, a systematic review of the extant literature was conducted with methodological considerations as a central focus. The following methodologic criteria were required for inclusion: the report (1) evaluated an index of sleep disturbance; (2) examined an outcome measure for suicidal behavior; (3) adjusted for presence of a depression diagnosis or depression severity, as a covariate; and (4) represented an original investigation as opposed to a chart review. Reports meeting inclusion criteria were further classified and reviewed according to: study design and timeframe; sample type and size; sleep disturbance, suicide risk, and depression covariate assessment measure(s); and presence of positive versus negative findings. Based on keyword search, the following search engines were used: PubMed and PsycINFO. Search criteria generated N = 82 articles representing original investigations focused on sleep disturbances and suicide outcomes. Of these, N = 18 met inclusion criteria for review based on systematic analysis. Of the reports identified, N = 18 evaluated insomnia or poor sleep quality symptoms, whereas N = 8 assessed nightmares in association with suicide risk. Despite considerable differences in study designs, samples, and assessment techniques, the comparison of such reports indicates preliminary, converging evidence for sleep disturbances as an empirical risk factor for suicidal behaviors, while highlighting important, future directions for increased investigation.

  1. Microbial Mat Compositional and Functional Sensitivity to Environmental Disturbance

    Directory of Open Access Journals (Sweden)

    Eva Christine Preisner

    2016-10-01

    Full Text Available The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. While studies have indicated that rare microbial taxa may provide a biological reservoir that supports long-term ecosystem stability, how this dynamic population is influenced by environmental parameters remains unclear. In this study, a microbial mat ecosystem located on San Salvador Island, The Bahamas was used as a model to examine how environmental disturbance affects the protein synthesis potential (PSP of rare and abundant archaeal and bacterial communities and how these changes impact potential biogeochemical processes. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1 during 2011-2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of 16S rRNA and rRNA genes from samples before and after the pulse disturbance showed significant changes in the diversity and PSP of abundant and rare taxa, suggesting overall compositional and functional sensitivity to environmental change. In both archaeal and bacterial communities, while the majority of taxa showed low PSP across conditions, the overall community PSP increased post-disturbance, with significant shifts occurring among abundant and rare taxa across and within phyla. Broadly, following the post-disturbance reduction in salinity, taxa within Halobacteria decreased while those within Crenarchaeota, Thaumarchaeota, Thermoplasmata, Cyanobacteria, and Proteobacteria, increased in abundance and PSP. Quantitative PCR of genes and transcripts involved in nitrogen and sulfur cycling showed concomitant shifts in biogeochemical cycling potential. Post-disturbance conditions increased the expression of genes involved in N-fixation, nitrification, denitrification, and sulfate reduction. Together, our findings show complex community adaptation to environmental

  2. Disturbance-mediated competition between perennial plants along a resource supply gradient

    Science.gov (United States)

    J. Stephen. Brewer

    2011-01-01

    Traditional views of ecological disturbance emphasize the role that physical disturbances play in reducing competition between populations and maintaining species coexistence. I present an alternative view that employs a simple Lotka–Volterra model to demonstrate how disturbance resistance, disturbance resilience and resource storage can increase competition between...

  3. Disturbance regimes and the historical range and variation in terrestrial ecosystems

    Science.gov (United States)

    Robert Keane

    2017-01-01

    Disturbances are major drivers of ecological dynamics and it is the cumulative effects of disturbances across space and time that define a disturbance regime and dictate biodiversity by influencing the ranges of vegetation structures, compositions, and processes on landscapes. This range and variation of landscape characteristics under historical disturbance regimes...

  4. Native species richness buffers invader impact in undisturbed but not disturbed grassland assemblages

    Science.gov (United States)

    Sarah M. Pinto; Yvette K. Ortega

    2016-01-01

    Many systems are prone to both exotic plant invasion and frequent natural disturbances. Native species richness can buffer the effects of invasion or disturbance when imposed in isolation, but it is largely unknown whether richness provides substantial resistance against invader impact in the face of disturbance. We experimentally examined how disturbance (...

  5. Disturbance and canopy gaps as indicators of forest health in the Blue Mountains of Oregon.

    Science.gov (United States)

    Jerome S. Beatty; Brian W. Geils; John E. Lundquist

    1995-01-01

    Disturbance profiles, indices based on both spatial and non-spatial statistics, are used to examine how small-scale disturbances and the resulting canopy gaps disrupt ecosystem patterns and processes in selected stands in the Blue Mountains of Oregon. The biological meaning of many indices remains undefined for small scale disturbance phenomena, but their disturbance...

  6. How similar are forest disturbance maps derived from different Landsat time series algorithms?

    Science.gov (United States)

    Warren B. Cohen; Sean P. Healey; Zhiqiang Yang; Stephen V. Stehman; C. Kenneth Brewer; Evan B. Brooks; Noel Gorelick; Chengqaun Huang; M. Joseph Hughes; Robert E. Kennedy; Thomas R. Loveland; Gretchen G. Moisen; Todd A. Schroeder; James E. Vogelmann; Curtis E. Woodcock; Limin Yang; Zhe Zhu

    2017-01-01

    Disturbance is a critical ecological process in forested systems, and disturbance maps are important for understanding forest dynamics. Landsat data are a key remote sensing dataset for monitoring forest disturbance and there recently has been major growth in the development of disturbance mapping algorithms. Many of these algorithms take advantage of the high temporal...

  7. Symbolic models for nonlinear control systems affected by disturbances

    Science.gov (United States)

    Borri, Alessandro; Pola, Giordano; Domenica Di Benedetto, Maria

    2012-10-01

    In the last few years, there has been a growing interest in the use of symbolic models for the formal verification and control design of purely continuous or hybrid systems. Symbolic models are abstract descriptions of continuous systems where one symbol corresponds to an 'aggregate' of continuous states. In this article, we face the problem of deriving symbolic models for nonlinear control systems affected by disturbances. The main contribution of this article is in proposing symbolic models that can be effectively constructed and that approximate nonlinear control systems affected by disturbances in the sense of alternating approximate bisimulation.

  8. Acid-base disturbance in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Bendtsen, Flemming; Møller, Søren

    2015-01-01

    PURPOSE: Acid-base disturbances were investigated in patients with cirrhosis in relation to hemodynamic derangement to analyze the hyperventilatory effects and the metabolic compensation. METHODS: A total of 66 patients with cirrhosis and 44 controls were investigated during a hemodynamic study......, and effects of unidentified ions (all Pacid-base disturbances could not be identified. CONCLUSION: Hypocapnic alkalosis is related to disease severity and hyperdynamic systemic circulation in patients with cirrhosis. The metabolic compensation includes...... alterations in serum albumin and water retention that may result in a delicate acid-base balance in these patients....

  9. Active rejection of persistent disturbances in flexible space structures

    Science.gov (United States)

    Hwang, Cheng-Neng; Jayasuriya, Suhada; Parlos, Alexander G.; Sunkel, John W.

    1990-01-01

    A dynamic compensator for active rejection of persistent disturbances in flexible space structures is designed on the principle of the H(infinity)-optimization of the sensitivity transfer function matrix. A general state space solution is formulated to the multiinput multioutput H(infinity)-optimal control problem, allowing the use of the H(infinity)-optimal synthesis algorithm for the state-space models of space structures that result from model order reduction. Disturbances encountered in flexible space structures, such as shuttle docking, are investigated using the high-mode and the reduced-order models of a cantilevered two-bay truss, demonstrating the applicability of the H(infinity)-optimal approach.

  10. Active disturbance rejection control of temperature for ultrastable optical cavities.

    Science.gov (United States)

    Pizzocaro, Marco; Calonico, Davide; Calosso, Claudio; Clivati, Cecilia; Costanzo, Giovanni A; Levi, Filippo; Mura, Alberto

    2013-02-01

    This paper describes the application of a novel active disturbance rejection control (ADRC) to the stabilization of the temperature of two ultra-stable Fabry-Perot cavities. The cavities are 10 cm long and entirely made of ultralow- expansion glass. The control is based on a linear extended state observer that estimates and compensates the disturbance in the system in real time. The resulting control is inherently robust and easy to tune. A digital implementation of ADRC gives a temperature instability of 200 μK at one day of integration time.

  11. Model tracking controller design of robot manipulator system with disturbances

    Directory of Open Access Journals (Sweden)

    Dazhong Wang

    2015-06-01

    Full Text Available In the model tracking control of robot manipulator system, the treatment of nonlinear uncertainty in the system has always been an active research field. This article establishes a kinetic equation for robot manipulator system based on Lagrange equation and proposes a model tracking control system based on differential divisor. On this basis, this article proposes a model tracking control scheme for robot manipulator systems with disturbances. The proposed scheme is robust stable under the external disturbances. At last, the system simulation approach is employed to verify the effectiveness of this scheme on robot manipulator control.

  12. Disturbance of shaped charge jets by bulging armour

    Energy Technology Data Exchange (ETDEWEB)

    Held, M. [TDW - Gesellschaft fuer Verteidigungstechnische Wirksysteme mbH, Schrobenhausen (Germany)

    2001-10-01

    Two flash X-ray pictures of the passing jet after a bulging armour are presented which give the disturbance effect to the jet - some earlier particulation time and iterative jet eruptions - but only after some time delay. The analysis of the jet velocities of the eruptions allows to calculate the time intervals or roughly the disturbance frequency of the used bulging armour arrangement. In this present paper two tests described with two ''new'' base inert materials - Dyneema - between two metal plates. (orig.)

  13. Revegetation studies on oil shale related disturbances in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Redente, E.F.; Cook, C.W.

    1982-06-01

    An interdisciplinary research project was initiated in 1976 to provide both basic and applied information that would aid in the reestablishment of natural functioning ecosystems on land disturbances associated with energy development. The approach included field, laboratory, and greenhouse experiments designed to provide both structural and functional information about disturbed ecological systems in the semiarid west. This report presents results from the sixth year of the study. Separate abstracts have been prepared for each of the 4 studies reported for inclusion in the Energy Data Base. (DMC)

  14. Circles Disturbed The Interplay of Mathematics and Narrative

    CERN Document Server

    Doxiadis, Apostolos

    2012-01-01

    Circles Disturbed brings together important thinkers in mathematics, history, and philosophy to explore the relationship between mathematics and narrative. The book's title recalls the last words of the great Greek mathematician Archimedes before he was slain by a Roman soldier--"Don't disturb my circles"--words that seem to refer to two radically different concerns: that of the practical person living in the concrete world of reality, and that of the theoretician lost in a world of abstraction. Stories and theorems are, in a sense, the natural languages of these two worlds--stories represent

  15. Numerical Study of Broadband Disturbance Development in APG Boundary Layer Flow

    Science.gov (United States)

    Chen, Weijia; Chen, Jim; Lo, Edmond

    2014-03-01

    A numerical model is developed with combined compact difference methods to simulation boundary layer transition problems. The model is used to investigate the formation and development of coherent structures in late stage of a laminar-turbulent transition initiated by a two-dimensional Tollmien-Schlichting (TS) wave and initially weak broadband disturbances. The numerical simulation closely follows the conditions in the experiments by Borodulin (2006). The boundary layer base flow has an Adverse Pressure Gradient (APG) with Hartree parameter βH = - 0.115. The instantaneous flow structures are visualized, which demonstrate results comparable with experiments. Interaction between the TS wave and broadband disturbances leads to the formation of Λ-vortices, Ω-vortices, and ring-like vortices. In comparison with those in classical transition paths, i.e., fundamental and subharmonic resonances, these structures are distributed in a random order and have distorted shapes. However, their local evolution properties are qualitatively similar with those in classical transition paths. The authors thank Nanyang Techonological Univerisity for funding support.

  16. The Effects of Lithium Carbonate Supplemented with Nitrazepam on Sleep Disturbance during Cannabis Abstinence.

    Science.gov (United States)

    Allsop, David J; Bartlett, Delwyn J; Johnston, Jennifer; Helliwell, David; Winstock, Adam; McGregor, Iain S; Lintzeris, Nicholas

    2015-10-15

    Sleep disturbance is a hallmark feature of cannabis withdrawal. In this study we explored the effects of lithium treatment supplemented with nitrazepam on objective and subjective measures of sleep quality during inpatient cannabis withdrawal. Treatment-seeking cannabis-dependent adults (n = 38) were admitted for 8 days to an inpatient withdrawal unit and randomized to either oral lithium (500 mg) or placebo, twice daily in a double-blind RCT. Restricted nitrazepam (10 mg) was available on demand (in response to poor sleep) on any 3 of the 7 nights. Dependent outcome measures for analysis included repeated daily objective actigraphy and subjective sleep measures throughout the 8 day detox, subjective cannabis withdrawal ratings, and detoxification completion rates. Based on actigraphy, lithium resulted in less fragmented sleep compared to placebo (p = 0.04), but no other objective measures were improved by lithium. Of the subjective measures, only nightmares were suppressed by lithium (p = 0.04). Lithium did not have a significant impact on the use of nitrazepam. Sleep bout length (p cannabis withdrawal. However the nitrazepam improved several actigraphy measures of sleep disturbance, warranting further investigation. Discord between objective and subjective sleep indices suggest caution in evaluating treatment interventions with self-report sleep data only. © 2015 American Academy of Sleep Medicine.

  17. The comparison of sleep disturbances between the subjects with headache and healthy subjects

    Directory of Open Access Journals (Sweden)

    Arash Bostani

    2015-11-01

    Full Text Available Background: Headache is one of the most common complaints of the patients referring to the treatment centers. Also, some studies have reported the correlation of sleep disturbances with migraine and tension headaches. This study was aimed to analyze the association of sleep disturbances with migraine and tension headaches. Methods: In this cross-sectional study, 1005 students of Kermanshah University of Medical Sciences were selected by stratified random sampling during the academic year 2013-2014. Having attracted the participation and cooperation of the participants, sleep disorder and symptoms of headache (migraine and tension tests were administered. Results: The overall prevalence of headache, migraine headache and tension headache in students of medical science were 73.8 %, 16.7 % and 30.9 %, respectively. 20.3% of medical students had sleep disorder. Difficulty in sleep onset, daytime fatigue, apnea and sadness and anxiety were associated with headache. Total sleep disorder was directly associated with migraine headache (P<0.05.Conclusion: There was a correlation between sleep disorders and headache, especially migraine headache. Considering the importance of sleep in the incidence of headaches, sleep hygiene education and changes in the quality and patterns of sleep are essential for students, which can greatly affect their individual and social life.

  18. Effects of music listening on stress, anxiety, and sleep quality for sleep-disturbed pregnant women.

    Science.gov (United States)

    Liu, Yu-Hsiang; Lee, ChihChen Sophia; Yu, Chen-Hsiang; Chen, Chung-Hey

    2016-01-01

    Prenatal sleep disturbance has been associated with undesirable birthing outcomes. To determine the effectiveness of listening to music at home in improving sleep quality, 121 Taiwanese pregnant women with poor sleep quality (Pittsburgh Sleep Quality Index [PSQI] score > 5) were systematically assigned, with a random start to music listening (n = 61) or control (n = 60) group. Participants in the music listening group self-regulated listening to music in addition to receiving general prenatal care similar to that in the control group for 2 weeks. The PSQI and State-Anxiety Inventory were used to assess outcomes. ANCOVA analyses were used with the pretest scores as covariates and showed significant improvement in sleep quality, stress, and anxiety in the music listening group compared with the control group. The most frequently used music genre by participants in the experimental group was lullabies, followed by classical music and crystal baby music. This study supported the theory that 2-week music listening interventions may reduce stress, anxiety, and yield better sleep quality for sleep-disturbed pregnant women. The analysis of participants' journals also implied that the expectant mothers' choices of musical genres may correlate more with perceived prenatal benefits or the desire to interact with their unborn child.

  19. A Discrete-time Variable Structure Disturbance Observer for Compensating Cutting Load Disturbances in CNC AC Servo Motors

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Y.E.; Kim, K.S.; Cho, D.I. [Seoul National University (Korea, Republic of)

    1997-03-01

    This paper develops an AC motor controller for CNC applications. The AC motor controller design is based on the variable structure system method; particularly, it adds a variable structure disturbance observer to a standard variable structure controller. The combined variable structure controller and disturbance observer approach is formulated in the discrete time to maximize the controller performance in digital implementation. In order to guarantee robust stability, a new separation principle that decouples the observer dynamics from the tracking error dynamics is derived. The designed controller is installed on the z-axis of a CNC machining center and milling experiments were performed. The results show excellent disturbance estimation properties, and improved performance on both position and speed tracking, when compared to the factory-designed servo controller. (author). refs., figs., tabs.

  20. Randomization Does Not Help Much, Comparability Does.

    Directory of Open Access Journals (Sweden)

    Uwe Saint-Mont

    Full Text Available According to R.A. Fisher, randomization "relieves the experimenter from the anxiety of considering innumerable causes by which the data may be disturbed." Since, in particular, it is said to control for known and unknown nuisance factors that may considerably challenge the validity of a result, it has become very popular. This contribution challenges the received view. First, looking for quantitative support, we study a number of straightforward, mathematically simple models. They all demonstrate that the optimism surrounding randomization is questionable: In small to medium-sized samples, random allocation of units to treatments typically yields a considerable imbalance between the groups, i.e., confounding due to randomization is the rule rather than the exception. In the second part of this contribution, the reasoning is extended to a number of traditional arguments in favour of randomization. This discussion is rather non-technical, and sometimes touches on the rather fundamental Frequentist/Bayesian debate. However, the result of this analysis turns out to be quite similar: While the contribution of randomization remains doubtful, comparability contributes much to a compelling conclusion. Summing up, classical experimentation based on sound background theory and the systematic construction of exchangeable groups seems to be advisable.

  1. Modelling of Disturbing Efects within Communication Channel for Safety-Related Communication System

    Directory of Open Access Journals (Sweden)

    Maria Franekova

    2007-01-01

    Full Text Available The aim of the paper is using of modelling within development of safety–related communication systems presented in the areas where guaranty of safety integrity level is required. In the paper basic principles used in the process of safety evaluation in closed transmission systems are summarised. Dangerous states of system are mainly caused by random failures of HW within non-trusted transmission system, by electromagnetic interference caused with noise or interferences and by systematic failures within specification of system. Main part of paper describes the simulation of disturbing effects within communication channel via programme Matlab, relations for determination of probability of undetected errors of code words with using block codes and results of residual error rate for Hamming code.

  2. Detection of Outliers in Panel Data of Intervention Effects Model Based on Variance of Remainder Disturbance

    Directory of Open Access Journals (Sweden)

    Yanfang Lyu

    2015-01-01

    Full Text Available The presence of outliers can result in seriously biased parameter estimates. In order to detect outliers in panel data models, this paper presents a modeling method to assess the intervention effects based on the variance of remainder disturbance using an arbitrary strictly positive twice continuously differentiable function. This paper also provides a Lagrange Multiplier (LM approach to detect and identify a general type of outlier. Furthermore, fixed effects models and random effects models are discussed to identify outliers and the corresponding LM test statistics are given. The LM test statistics for an individual-based model to detect outliers are given as a particular case. Finally, this paper performs an application using panel data and explains the advantages of the proposed method.

  3. Assessing anthropogenic and natural disturbances: forest response to similarly aged clearcut and tornado disturbances in an east Tennessee oak-hickory forest

    Science.gov (United States)

    Jonathan C. McGrath; Wayne K. Clatterbuck

    2013-01-01

    In February of 1993, an F3 tornado caused a large-scale disturbance in an east Tennessee oak-hickory (Quercus spp.-Carya spp.) forest. Vegetation response to anthropogenic and natural disturbances was compared by examining two tornado-disturbed areas and five adjacent 1-acre silvicultural clearcut areas unaffected by the tornado...

  4. The Stimulation Effect of Auricular Magnetic Press Pellets on Older Female Adults with Sleep Disturbance Undergoing Polysomnographic Evaluation

    Directory of Open Access Journals (Sweden)

    Chyi Lo

    2013-01-01

    Full Text Available Study Objectives. To examine the stimulation effect of auricular magnetic press pellet therapy on older female adults with sleep disturbance as determined by polysomnography (PSG. Design. Randomized, single-blind, experimental-controlled, parallel-group. Setting. Community. Participants. Twenty-seven older female adults with sleep disturbance according to the Pittsburgh Sleep Quality Index (PSQI >5 for at least 3 months were recruited. Participants were screened by both the Hospital Anxiety and Depression Scale (HADS and the Mini-Mental State Examination (MMSE, as well as polysomnography prior to randomization. Interventions. All eligible participants were randomly allocated into the experimental or control group. Both groups were taped with magnetic press pellet on auricular points for 3 weeks. The experimental group was treated by applying pressure on the magnetic press pellets 3 times per day while no stimulation was applied on the control group. Measurements and Results. Both groups were measured by PSG and PSQI at the beginning of the study and 3 weeks after the study. Both groups showed improvements on PSQI scores compared to the baseline. One-way analysis of covariance adjusted for baseline scores showed that significant improvements of PSG-derived sleep parameters, such as sleep efficiency, were found in the experimental group. However, no significant differences between groups were observed in the proportion of sleep stages with the exception of Stage 2. Conclusions. Auricular therapy using magnetic pellets and stimulation by pressing was more effective in improving the sleep quality compared to auricular therapy without any stimulation.

  5. Sleep disturbances in a clinical forensic psychiatric population

    NARCIS (Netherlands)

    Kamphuis, Jeanine; Karsten, Julie; de Weerd, Al; Lancel, Marike

    2013-01-01

    Objective: Poor sleep is known to cause detrimental effects on the course of diverse psychiatric disorders and is a putative risk factor for hostility and aggression. Thus, sleep may be crucial in forensic psychiatric practice. However, little is known about the prevalence of sleep disturbances in

  6. Childhood Abuse, Body Image Disturbance, and Eating Disorders.

    Science.gov (United States)

    Schaaf, Kristin K.; McCanne, Thomas R.

    1994-01-01

    This study examined the relationships among childhood sexual and physical abuse, body image disturbance, and eating disorder symptomatology in college students, of whom 29 had been sexually abused, 32 physically abused, and 29 nonabused. There was no evidence that child sexual or physical abuse was associated with the development of body image…

  7. Television Images and Adolescent Girls' Body Image Disturbance.

    Science.gov (United States)

    Botta, Renee A.

    1999-01-01

    Contributes to scholarship on the effects of media images on adolescents, using social-comparison theory and critical-viewing theory. Finds that media do have an impact on body-image disturbance. Suggests that body-image processing is the key to understanding how television images affect adolescent girls' body-image attitudes and behaviors. (SR)

  8. An assessment of psychiatric disturbances in graves disease in a ...

    African Journals Online (AJOL)

    ... of psychiatric disturbances in graves disease in a medical college in eastern ... the standard error of difference, the chi-square test, and paired Student's T-test. ... Fifteen patients (41.67%) were diagnosed with generalized anxiety disorders ...

  9. An ecosystem model for tropical forest disturbance and selective logging

    Science.gov (United States)

    Maoyi Huang; Gregory P. Asner; Michael Keller; Joseph A. Berry

    2008-01-01

    [1] A new three-dimensional version of the Carnegie-Ames-Stanford Approach (CASA) ecosystem model (CASA-3D) was developed to simulate regional carbon cycling in tropical forest ecosystems after disturbances such as logging. CASA-3D has the following new features: (1) an alternative approach for calculating absorbed photosynthetically active radiation (APAR) using new...

  10. Unusual subauroral neutral wind disturbances during geomagnetic storms

    Science.gov (United States)

    Zhang, S.; Erickson, P. J.; Holt, J. M.

    2016-12-01

    Under the influence of geomagnetic storms, general circulation of the global thermosphere undergoes substantial changes that vary with latitudes. High latitude heating processes establish pressure gradients both vertically and horizontally. The equatorward wind surge and the associated westward wind enhancement are a typical disturbance wind characteristic that affacts ionosphere and thermosphere dynamics at mid-, low, and equatorial latitudes. At subauroral latitudes, however, new observations of neutral wind disturbances show some "abnormal" (unusual) behaviors in responding to complicated ion-neutral coupling processes. During the 2015 St. Patrick's Day great geomagnetic storm, incoherent scatter radar measurements at Millstone Hill show the following salient variations: (1) oscillating meridional wind disturbances with the Traveling Atmosphere Disturbance (TAD) feature; (2) vertical wind signature; (3) pre-mindnight poleward wind surges. The latter two variations appear to be associated with strong ion-neutral interaction developed during the subauroral polarization streams (SAPS) presence. Strong frictional heating caused by the relative velocity between the ions with SAPS speed and the neutrals leads to appreciable thermospheric upperwelling. Strong westward ion drifts shown as SAPS also enhance the wseward neutral flow, which subsequently causes a poleward component of the meridional wind due to the Coriolis force. This paper will present these observations of the wind and discuss ion-neutral coupling effects associated with SAPS.

  11. Disturbance, diversity and distributions in Central African rain forest

    NARCIS (Netherlands)

    Gemerden, van B.S.

    2004-01-01

    The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are

  12. Adaptive disturbance attenuation via logic-based switching

    NARCIS (Netherlands)

    Battistelli, Giorgio; Mari, Daniele; Selvi, Daniela; Tesi, Alberto; Tesi, Pietro

    2014-01-01

    The problem of attenuating unknown and possibly time-varying disturbances acting on a linear time-invariant dynamical system is addressed by means of an adaptive switching control approach. Given a family of pre-designed stabilizing controllers, a supervisory unit infers in real-time the potential

  13. Sleep Disturbances in Patients with Rheumatoid Arthritis | Abbasi ...

    African Journals Online (AJOL)

    BACKGROUND: Sleep problems are frequent in chronic diseases like rheumatoid arthritis (RA). The present study was conducted to determine frequency of sleep disturbances and their relations with disease severity. METHODS: The present case-control study was performed on 100 rheumatoid patients who were referred ...

  14. Evaluation of Wraparound Services for Severely Emotionally Disturbed Youths

    Science.gov (United States)

    Mears, Susan L.; Yaffe, Joanne; Harris, Norma J.

    2009-01-01

    Objectives: Services to children and adolescents with a severe emotional disturbance (SED) have long been inadequate. The wraparound approach has emerged as a promising practice that could address the needs of children with SED and their families through a strength-based, individualized, family-focused team process that emphasizes flexible service…

  15. Studies on circadian rhythm disturbances and melatonin in delirium

    NARCIS (Netherlands)

    de Jonghe, A.-M.

    2014-01-01

    The circadian sleep/wake rhythm disturbances that are seen in delirium and the role of melatonin supplementation provide a new angle in delirium research. More research is needed to determine the role of melatonin in the pathophysiological mechanisms of delirium and to determine whether the

  16. Sensitivity of climate mitigation strategies to natural disturbances

    Science.gov (United States)

    Le Page, Y.; Hurtt, G.; Thomson, A. M.; Bond-Lamberty, B.; Patel, P.; Wise, M.; Calvin, K.; Kyle, P.; Clarke, L.; Edmonds, J.; Janetos, A.

    2013-03-01

    The present and future concentration of atmospheric carbon dioxide depends on both anthropogenic and natural sources and sinks of carbon. Most proposed climate mitigation strategies rely on a progressive transition to carbon-efficient technologies to reduce industrial emissions, substantially supported by policies to maintain or enhance the terrestrial carbon stock in forests and other ecosystems. This strategy may be challenged if terrestrial sequestration capacity is affected by future climate feedbacks, but how and to what extent is little understood. Here, we show that climate mitigation strategies are highly sensitive to future natural disturbance rates (e.g. fires, hurricanes, droughts), because of the potential effect of disturbances on the terrestrial carbon balance. Generally, altered disturbance rates affect the pace of societal and technological transitions required to achieve the mitigation target, with substantial consequences on the energy sector and the global economy. An understanding of the future dynamics and consequences of natural disturbances on terrestrial carbon balance is thus essential for developing robust climate mitigation strategies and policies.

  17. Association of Sleep Disturbances With Reduced Semen Quality

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Andersson, Anna-Maria; Skakkebæk, Niels Erik

    2013-01-01

    recruited in Copenhagen at the time of determination of fitness for military service between January 2008 and June 2011. All of the men delivered a semen sample, had a blood sample drawn, underwent a physical examination, and answered a questionnaire including information about sleep disturbances. Sleep...

  18. Restoration of breeding by snowy plovers following protection from disturbance

    Science.gov (United States)

    Lafferty, K.D.; Goodman, D.; Sandoval, C.P.

    2006-01-01

    Promoting recreation and preserving wildlife are often dual missions for land managers, yet recreation may impact wildlife. Because individual disturbances are seemingly inconsequential, it is difficult to convince the public that there is a conservation value to restricting recreation to reduce disturbance. We studied threatened western snowy plovers (Charadrius alexandrinus nivosus) at a public beach (Sands Beach, Coal Oil Point Reserve) in Santa Barbara, California (USA) before and during a period when a barrier directed foot traffic away from a section of upper beach where snowy plovers roost. The barrier reduced disturbance rates by more than half. Snowy plovers increased in abundance (throughout the season) and their distribution contracted to within the protected area. Snowy plovers that were outside the protected area in the morning moved inside as people began using the beach. Experiments with quail eggs indicated an 8% daily risk of nest trampling outside the protected area. Before protection, plovers did not breed at Coal Oil Point. During protection, snowy plovers bred in increasing numbers each year and had high success at fledging young. These results demonstrate how recreational disturbance can degrade habitat for shorebirds and that protecting quality habitat may have large benefits for wildlife and small impacts to recreation. ?? Springer 2006.

  19. Diversity of mesofauna and macrofauna in protected and disturbed ...

    African Journals Online (AJOL)

    High biodiversity of the soil fauna can be an indicator of soil fertility and its ability to sustain complex food chain, but fauna diversity alone is rarely used as a measure of these attributes. In this study we ... These results demonstrate the need for proper soil management practices to restore biodiversity loss in disturbed soils.

  20. Effects of tropical montane forest disturbance on epiphytic macrolichens.

    Science.gov (United States)

    Benítez, Angel; Prieto, María; González, Yadira; Aragón, Gregorio

    2012-12-15

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for "shade-adapted lichens", while the richness of "heliophytic lichens" increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Disturbance and Climate Change in the Interior West (Chapter 6)

    Science.gov (United States)

    Paulette L. Ford; Jeanne K. Chambers; Sharon J. Coe; Burton C. Pendleton

    2012-01-01

    Within the continental United States, average annual temperature increased during the Twentieth Century by approximately 0.65 ºC. The most extreme warming occurred throughout the northern and western United States (IPCC 2007a; Williams and others 2010). Disturbances such as fire, drought, grazing, urbanization, and energy development are predicted to have a heightened...

  2. Intestinal mast cells in gut inflammation and motility disturbances

    NARCIS (Netherlands)

    de Winter, Benedicte Y.; van den Wijngaard, Rene M.; de Jonge, Wouter J.

    2012-01-01

    Mast cells may be regarded as prototypes of innate immune cells that can be controlled by neuronal mediators. Their activation has been implicated in many types of neuro-inflammatory responses, and related disturbances of gut motility, via direct or indirect mechanisms that involve several

  3. Using landscape disturbance and succession models to support forest management

    Science.gov (United States)

    Eric J. Gustafson; Brian R. Sturtevant; Anatoly S. Shvidenko; Robert M. Scheller

    2010-01-01

    Managers of forested landscapes must account for multiple, interacting ecological processes operating at broad spatial and temporal scales. These interactions can be of such complexity that predictions of future forest ecosystem states are beyond the analytical capability of the human mind. Landscape disturbance and succession models (LDSM) are predictive and...

  4. Modeling disturbance and succession in forest landscapes using LANDIS: introduction

    Science.gov (United States)

    Brian R. Sturtevant; Eric J. Gustafson; Hong S. He

    2004-01-01

    Modeling forest landscape change is challenging because it involves the interaction of a variety of factors and processes, such as climate, succession, disturbance, and management. These processes occur at various spatial and temporal scales, and the interactions can be complex on heterogeneous landscapes. Because controlled field experiments designed to investigate...

  5. Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

    Science.gov (United States)

    Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

    2013-01-01

    Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

  6. Biomarker responses of mussels exposed to earthquake disturbances

    Science.gov (United States)

    Chandurvelan, Rathishri; Marsden, Islay D.; Glover, Chris N.; Gaw, Sally

    2016-12-01

    The green-lipped mussel, Perna canaliculus is recognised as a bioindicator of coastal contamination in New Zealand (NZ). Mussels (shell length 60-80 mm) were collected from three intertidal areas of Canterbury in the South Island of NZ prior to extreme earthquake disturbances on 22nd February 2011, and 9 months later in October 2011. Trace elements, including arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), were measured in the gills, digestive gland, foot and mantle. Metal levels in tissues were site specific, and mostly unaffected by earthquake disturbances. Physiological biomarkers were negatively affected by earthquake disturbances and mussels from the Port of Lyttelton had higher negative scope for growth post-earthquake. Metallothionein-like protein in the digestive gland correlated with metal content of tissues, as did catalase activity in the gill and lipid peroxidation values for the digestive gland. This research demonstrates that physiological and other biomarkers are effective at detecting the effects of multiple stressors following seismic disturbances.

  7. Nonlinear Feedforward Control for Wind Disturbance Rejection on Autonomous Helicopter

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; A. Danapalasingam, Kumeresan

    2010-01-01

    for the purpose. The model is inverted for the calculation of rotor collective and cyclic pitch angles given the wind disturbance. The control strategy is then applied on a small helicopter in a controlled wind environment and flight tests demonstrates the effectiveness and advantage of the feedforward controller....

  8. The effect of anthropogenic disturbances on population structure ...

    African Journals Online (AJOL)

    The effect of anthropogenic disturbances on population structure and regeneration of Scorodophloeus fischeri and Manilkara sulcata in coastal forests of Tanzania. ... best in Zaraninge forest with high density of trees with diameter at breast height (DBH) between 10–50cm and a higher seedling density than in other forests.

  9. Tulathromycin disturbs blood oxidative and coagulation status | Er ...

    African Journals Online (AJOL)

    Tulathromycin disturbs blood oxidative and coagulation status. ... Tulathromycin was administered to eight rabbits, and blood samples were obtained 0, 1, 5, 10 and 15 days after treatment. Indicators of serum ... In conclusion, tulathromycin may cause oxidative damage and coagulation disorders during the treatment period.

  10. Further Validation of the Iowa Sleep Disturbances Inventory

    Science.gov (United States)

    Koffel, Erin

    2011-01-01

    This study examined the reliability and validity of an expanded version of the Iowa Sleep Disturbances Inventory (ISDI; Koffel & Watson, 2010) in 2 samples (219 college students and 200 psychiatric patients). The expanded ISDI includes the scales Sleep Paralysis and Sleep Hallucinations. These scales, along with the Nightmares scale, help define a…

  11. Determining landscape extent for succession and disturbance simulation modeling

    Science.gov (United States)

    Eva C. Karau; Robert E. Keane

    2007-01-01

    Dividing regions into manageable landscape units presents special problems in landscape ecology and land management. Ideally, a landscape should be large enough to capture a broad range of vegetation, environmental and disturbance dynamics, but small enough to be useful for focused management objectives. The purpose of this study was to determine the optimal landscape...

  12. Conservation importance of early post-disturbance temperate forests

    Science.gov (United States)

    Charles Kwit; David I. King; Beverly Collins; Mark E. Swanson

    2014-01-01

    The early post-disturbance stage of temperate forest succession (also referred to as 'early-seral' or 'early-successional' forest) has been the subject of interest and debate. Often thought of as an ephemeral (and often disorganized) state of eventual closed-canopy systems, its direct and immediate role in conservation traditionally has been ignored...

  13. Propagation of disturbances as voltage fluctuations in transmission networks

    Directory of Open Access Journals (Sweden)

    Albert Hermina

    2016-08-01

    Full Text Available Significant changes occurred in the power system in Romania in recent years by reducing the power used in the system, the number of classic power sources in operation as well as by implementing renewable energy sources, have determined short circuit power reduction (node rigidity in the points where disturbing users are connected, that in the absence of adequate measures, result in disturbances above acceptable levels. The paper analyzes two power systems areas in which are connected users that cause voltage fluctuation. Disturbances as voltage fluctuations resulting in these nodes may exceed the acceptable values and can spread in the transmission network affecting power quality over large system areas. The analysis conducted reveals the influence of short circuit power in nodes where these users are connected and highlights the fact that in some cases (e.g. lines out of operation for maintenance, shutdown of classic units in the area the disturbances in the transmission network sent to the users at lower voltages may have values above those allowed. Technical Code of existing power transmission network makes no reference to voltage fluctuations, as a rule, in the electricity transmission network was considered that this phenomenon should not exist.

  14. Child Abuse and Aggression among Seriously Emotionally Disturbed Children

    Science.gov (United States)

    Ford, Julian D.; Fraleigh, Lisa A.; Connor, Daniel F.

    2010-01-01

    Abused children may be at risk for problems with aggression. In a sample of 397 seriously emotionally disturbed children, reactive aggression was associated with documented history of physical abuse but not sexual abuse. Girls were equally likely to be classified as reactively aggressive regardless of physical abuse history, but boys with physical…

  15. Emotional Disturbance. Fact Sheet = Problemas Emocionales. Hojas Informativas Sobre Discapacidades.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet, written in both English and Spanish, provides a definition, information on incidence, typical characteristics, and educational implications of emotional disturbance. The definition is from the Individuals with Disabilities Education Act (IDEA) and incidence in 1999-2000 is reported as about 470,000 children and youth. Educational…

  16. Advances in modeling soil erosion after disturbance on rangelands

    Science.gov (United States)

    Research has been undertaken to develop process based models that predict soil erosion rate after disturbance on rangelands. In these models soil detachment is predicted as a combination of multiple erosion processes, rain splash and thin sheet flow (splash and sheet) detachment and concentrated flo...

  17. Modeling dynamic behavior of superconducting maglev systems under external disturbances

    Science.gov (United States)

    Huang, Chen-Guang; Xue, Cun; Yong, Hua-Dong; Zhou, You-He

    2017-08-01

    For a maglev system, vertical and lateral displacements of the levitation body may simultaneously occur under external disturbances, which often results in changes in the levitation and guidance forces and even causes some serious malfunctions. To fully understand the effect of external disturbances on the levitation performance, in this work, we build a two-dimensional numerical model on the basis of Newton's second law of motion and a mathematical formulation derived from magnetoquasistatic Maxwell's equations together with a nonlinear constitutive relation between the electric field and the current density. By using this model, we present an analysis of dynamic behavior for two typical maglev systems consisting of an infinitely long superconductor and a guideway of different arrangements of infinitely long parallel permanent magnets. The results show that during the vertical movement, the levitation force is closely associated with the flux motion and the moving velocity of the superconductor. After being disturbed at the working position, the superconductor has a disturbance-induced initial velocity and then starts to periodically vibrate in both lateral and vertical directions. Meanwhile, the lateral and vertical vibration centers gradually drift along their vibration directions. The larger the initial velocity, the faster their vibration centers drift. However, the vertical drift of the vertical vibration center seems to be independent of the direction of the initial velocity. In addition, due to the lateral and vertical drifts, the equilibrium position of the superconductor in the maglev systems is not a space point but a continuous range.

  18. Sleep disturbances in critically ill patients in ICU

    DEFF Research Database (Denmark)

    Boyko, Yuliya; Ording, H; Jennum, P

    2012-01-01

    Sleep disturbances in the intensive care unit (ICU) seem to lead to development of delirium, prolonged ICU stay, and increased mortality. That is why sufficient sleep is important for good outcome and recovery in critically ill patients. A variety of small studies reveal pathological sleep patterns...

  19. Variation of surface electric field during geomagnetic disturbed ...

    Indian Academy of Sciences (India)

    disturbed period at Maitri, Antarctica. N Jeni Victor, C Panneerselvam∗ and C P Anil Kumar. Equatorial Geophysical Research Laboratory, Indian Institute of Geomagnetism, Krishnapuram,. Tirunelveli 627 011, India. ∗Corresponding author. e-mail: panneer.iig@gmail.com. The paper discusses on the variations of the ...

  20. Forest disturbance type differentially affects seasonal moose forage

    Science.gov (United States)

    R.A. Lautenschlager; Hewlette S. Crawford; Martin R. Stokes; Timothy L. Stone

    1997-01-01

    We examined the effects of forest disturbance on forage availability, moose (Alces alces) seasonal forage selection, and predicted in vivo digestibility in eastern Maine. Wet-mass estimates and dry-mass conversions of species consumed by 3 tamed moose were made throughout the year (late winter, early spring, late spring, summer, fall, early winter)...

  1. Use of Videotape Feedback with Severely Disturbed Adolescents.

    Science.gov (United States)

    Michel, Jane; Blitstein, Sheldon

    1979-01-01

    Summarizes the design and effects of a group therapy project using videotape feedback with seriously disturbed adolescents. Offers anecdotal evidence that the feedback facilitated the correction of the participants' distorted body images, low self-esteem, lack of capacity for self-observation, and poor peer relationships. (SS)

  2. Meadow sensitivity to natural and anthropogenic disturbance [chapter 5

    Science.gov (United States)

    Jerry R. Miller; Mark L. Lord; Dru Germanoski

    2011-01-01

    Investigations of geomorphic responses to natural and anthropogenic disturbances have revealed marked differences in the rate, magnitude, and nature by which different watersheds, or components of a given watershed, adjust to perturbations. These differences in response are often characterized using the concept of landform sensitivity. The term sensitivity has been...

  3. Rill erosion in natural and disturbed forests: 1. Measurements

    Science.gov (United States)

    P. R. Robichaud; J. W. Wagenbrenner; R. E. Brown

    2010-01-01

    Rill erosion can be a large portion of the total erosion in disturbed forests, but measurements of the runoff and erosion at the rill scale are uncommon. Simulated rill erosion experiments were conducted in two forested areas in the northwestern United States on slopes ranging from 18 to 79%. We compared runoff rates, runoff velocities, and sediment flux rates from...

  4. Effects of Disturbance on Populations of Marine Mammals

    Science.gov (United States)

    2015-09-30

    population consequences of disturbance. Methods in Ecology and Evolution . doi: 10.1111/2041-210X.12411. [published, refereed] New, L.F., J.S. Clark, D.P...Thomas, P. Tyack, and J. Harwood. 2014. Using short-term measures of behaviour to estimate long-term fitness of southern elephant seals. Marine Ecology

  5. Fluent Persuasive Writing with Counterarguments for Students with Emotional Disturbance

    Science.gov (United States)

    Mastropieri, Margo A.; Scruggs, Thomas E.; Cerar, Nancy Irby; Allen-Bronaugh, Dannette; Thompson, Catherine; Guckert, Mary; Leins, Pat; Hauth, Clara; Cuenca-Sanchez, Yojanna

    2014-01-01

    Twelve seventh- and eighth-grade students with emotional disturbance participated in a multiple probe, multiple baseline design two-phase intervention study to improve persuasive writing skills. The first phase after baseline taught students to plan and write persuasive essays including counterarguments. In the second phase, students were taught…

  6. Dynamics of a railway vehicle on a laterally disturbed track

    DEFF Research Database (Denmark)

    Christiansen, Lasse Engbo; True, Hans

    2017-01-01

    In this article a theoretical investigation of the dynamics of a railway bogie running on a tangent track with a periodic disturbance of the lateral track geometry is presented. The dynamics is computed for two values of the speed of the vehicle in combination with different values...

  7. Disturbance rejection in formation keeping control of nonholonomic wheeled robots

    NARCIS (Netherlands)

    Jafarian, Matin; Vos, Ewoud; De Persis, Claudio; Scherpen, Jacquelien; Schaft, van der Arjan

    2016-01-01

    This paper presents the results of formation keeping control of a group of nonholonomic wheeled robots within the port-Hamiltonian framework and in the presence of matched input disturbances. Two scenarios on the internal damping of the dynamics of the robots are considered: strictly output passive

  8. Book Review Overcoming Body Image Disturbance: A Programme ...

    African Journals Online (AJOL)

    Book Review Overcoming Body Image Disturbance: A Programme for People with Eating Disorders By Lorraine Bell and Jenny Rushforth (2008). Carla Dukas. Abstract. Routledge, London Paperback, ISBN 978-0-415-42330-4, ZAR 393 160 pages40. Journal of Child and Adolescent Mental Health 2008, 20(2): 133–134.

  9. Sensitivity of climate mitigation strategies to natural disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Le Page, Yannick LB; Hurtt, George; Thomson, Allison M.; Bond-Lamberty, Benjamin; Patel, Pralit L.; Wise, Marshall A.; Calvin, Katherine V.; Kyle, G. Page; Clarke, Leon E.; Edmonds, James A.; Janetos, Anthony C.

    2013-02-19

    The present and future concentration of atmospheric carbon dioxide depends on both anthropogenic and natural sources and sinks of carbon. Most proposed climate mitigation strategies rely on a progressive transition to carbon12 efficient technologies to reduce industrial emissions, substantially supported by policies to maintain or enhance the terrestrial carbon stock in forests and other ecosystems. This strategy may be challenged if terrestrial sequestration capacity is affected by future climate feedbacks, but how and to what extent is little understood. Here, we show that climate mitigation strategies are highly sensitive to future natural disturbance rates (e.g. fires, hurricanes, droughts), because of potential effect of disturbances on the terrestrial carbon balance. Generally, altered disturbance rates affect the pace of societal and technological transitions required to achieve the mitigation target, with substantial consequences on the energy sector and on the global economy. Understanding the future dynamics and consequences of natural disturbances on terrestrial carbon balance is thus essential for developing robust climate mitigation strategies and policies

  10. Chronic Sleep Disturbance Impairs Glucose Homeostasis in Rats

    NARCIS (Netherlands)

    Barf, R. Paulien; Meerlo, Peter; Scheurink, Anton J. W.

    2010-01-01

    Epidemiological studies have shown an association between short or disrupted sleep and an increased risk for metabolic disorders. To assess a possible causal relationship, we examined the effects of experimental sleep disturbance on glucose regulation in Wistar rats under controlled laboratory

  11. Severe psychological disturbance resulting from abuse of nasal decongestants.

    Science.gov (United States)

    Blackwood, G W

    1982-04-01

    A case is reported in which a lady suffered long-term personality change, a paranoid psychosis of several months duration, and an acute delirium, secondary to abuse of Vicks Sinex Nasal Spray and Vicks Vaporub. The problems were reversible on withdrawal of these well used products which have not previously been reported to cause psychological disturbance.

  12. Performance-based procurement for low disturbance brdige construction projects

    NARCIS (Netherlands)

    Sebastian, R.; Claeson-Jonsson, C.; Di Giulio, R.

    2013-01-01

    Purpose – This paper aims to introduce a method of performance-based procurement, based on the most economically advantageous tender (MEAT), for low-disturbance bridge construction projects in urban environment. Design/methodology/approach – The first part of this paper reviews the key performance

  13. Effects of human disturbance on the breeding success of gulls

    Science.gov (United States)

    Henry C. Robert; C. John Ralph

    1975-01-01

    A number of factors have been suggested as affecting reproductive success in gulls. In this study we have attempted to isolate the effect of human disturbance on breeding success. We held other factors such as age of birds, terrain, and density of colony as constant as was practicable with a varied colony environment. There have been several previous discussions of the...

  14. [Sleep disturbances--cause or result of depression].

    Science.gov (United States)

    Heitzman, Janusz

    2009-01-01

    Sleep disturbances are a very sensitive indicator, which allows identifying various psychic illnesses, especially depression. Irrelevant of the very nature of sleep disturbances, their presence can tell us about the onset of depression or its ending. The mechanism of sleep disturbances seems to be tightly bound with the physiology of depression. Besides physiological, neuroendocrine and behavioural parameters, which are altered in depression, sleep disturbances play a more exposed role in the recent years. This has been brought about by a better identification of daily rhythm disorders in major depressive disorder (MDD), bipolar disorder (BD) or seasonal affective disorder (SAD) and the discovery of a correlation between lowered mood and changes in the rhythm and level of melatonine secretion. Also, the discovery of the substance which is supposedly correcting the disordered circadian rhythm (agomelatine), means a step forward in the search for an effective treatment of depression. It is worthy to look closer into its regulatory effect on the disordered circadian rhythm, which is not only to give an antidepressive effect, but in a visible improvement of sleep architecture and functioning during the day.

  15. Are sleep disturbances preclinical markers of Parkinson’s disease?

    DEFF Research Database (Denmark)

    Brito dos Santos, Altair; Kohlmeier, Kristi Anne; Barreto, George

    2015-01-01

    Parkinson’s disease (PD) is a neurobehavioral disorder characterized by motor symptoms and signs, and non-motor abnormalities such as olfactory dysfunction, pain, sleep disorders and cognitive impairment. Amongst these alterations, sleep disturbances play an important role in the pathology...

  16. Variation of surface electric field during geomagnetic disturbed ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 124; Issue 8. Variation of surface electric field ... Diurnal variation of surface electric field measured at Maitri shows a similar variation with worldwide thunderstorm activity, whereas the departure of the field is observed during disturbed periods. This part of the field ...

  17. Comparison Of Power Quality Disturbances Classification Based On Neural Network

    Directory of Open Access Journals (Sweden)

    Nway Nway Kyaw Win

    2015-07-01

    Full Text Available Abstract Power quality disturbances PQDs result serious problems in the reliability safety and economy of power system network. In order to improve electric power quality events the detection and classification of PQDs must be made type of transient fault. Software analysis of wavelet transform with multiresolution analysis MRA algorithm and feed forward neural network probabilistic and multilayer feed forward neural network based methodology for automatic classification of eight types of PQ signals flicker harmonics sag swell impulse fluctuation notch and oscillatory will be presented. The wavelet family Db4 is chosen in this system to calculate the values of detailed energy distributions as input features for classification because it can perform well in detecting and localizing various types of PQ disturbances. This technique classifies the types of PQDs problem sevents.The classifiers classify and identify the disturbance type according to the energy distribution. The results show that the PNN can analyze different power disturbance types efficiently. Therefore it can be seen that PNN has better classification accuracy than MLFF.

  18. Spatially Estimating Disturbance of Harbor Seals (Phoca vitulina.

    Directory of Open Access Journals (Sweden)

    John K Jansen

    Full Text Available Tidewater glacial fjords in Alaska provide habitat for some of the largest aggregations of harbor seals (Phoca vitulina, with calved ice serving as platforms for birthing and nursing pups, molting, and resting. These fjords have also been popular destinations for tour ships for more than a century, with dramatic increases in vessel traffic since the 1980s. Seals on ice are known to flush into the water when approached by tour ships, but estimating the exposure to disturbance across populations is difficult. Using aerial transect sampling while simultaneously tracking vessel movements, we estimated the spatial overlap between seals on ice and cruise ships in Disenchantment Bay, Alaska, USA. By integrating previously estimated rates of disturbance as a function of distance with an 'intensity surface' modeled spatially from seal locations in the surveys, we calculated probabilities of seals flushing during three separate ship visits. By combining our estimate of seals flushed with a modeled estimate of the total fjord population, we predict that up to 14% of the seals (up to 11% of pups hauled out would have flushed into the water, depending on the route taken by ships relative to seal aggregations. Such high potential for broad-scale disturbance by single vessels (when up to 4 ships visit per day was unexpected and underscores the need to 1 better understand long-term effects of disturbance; 2 regularly monitor populations exposed to high vessel traffic; and 3 develop conservation measures to reduce seal-ship overlap.

  19. Pseudologia fantastica and gender identity disturbance in a Chinese male.

    Science.gov (United States)

    Leung, C M; Lai, K; Shum, K; Lee, G

    1995-06-01

    A Chinese patient with pathological lying (pseudologia fantastica) and gender identity disturbance is described. The stories "save face" and lack a truly self-aggrandising quality. The importance of keeping "face" and maintaining modest behaviour in the Chinese culture is central to the psychopathology.

  20. Emotional Disturbance and Its Treatment in a Nutshell

    Science.gov (United States)

    Ellis, Albert

    1971-01-01

    The author suggests that human beings could eliminate their usual feelings of disturbance and upsetness and retain their appropriate feelings of disappointment and annoyance if they stop demanding and awfulizing" reality and dictating that it be other than it indubitably is. (Author/CG)

  1. Legislative Ambiguity and the Accurate Identification of Seriously Emotionally Disturbed.

    Science.gov (United States)

    Ostrander, Rick; And Others

    1988-01-01

    Surveyed school psychologists (N=127) practicing under three types of state criteria used in identifying children as seriously emotionally disturbed (SED) to determine the legal accuracy of their identifications of 12 behavioral descriptions of specific disorders. Found considerable differences in the perceptions of school psychology personnel.…

  2. Behaviour of organised disturbances in fully developed turbulent ...

    Indian Academy of Sciences (India)

    In our earlier work we have shown the relevance of stability theory in understanding the sustenance of turbulence in turbulent boundary layers. Here we adopt the same model to study the evolution of organised disturbances in turbulent channel flow. Since the dominant modes are wall modes we find that the stability ...

  3. Ubiquitous Fast Propagating Intensity Disturbances in Solar Chromosphere

    Science.gov (United States)

    Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Winebarger, A.; hide

    2016-01-01

    High cadence observations by the slit-jaw (SJ) optics system of the sounding rocket experiment "the Chromospheric Lyman Alpha SpectroPolarimeter (CLASP)" reveal ubiquitous intensity disturbances that recurrently propagate in either the chromosphere, transition region, or both at a speed much higher than the sound speed.

  4. Erosion over time on severely disturbed granitic soils: a model

    Science.gov (United States)

    W. F. Megahan

    1974-01-01

    A negative exponential equation containing three parameters was derived to describe time trends in surface erosion on severely disturbed soils. Data from four different studies of surface erosion on roads constructed from the granitic materials found in the Idaho Batholith were used to develop equation parameters. The evidence suggests that surface "armoring...

  5. Simulation of landscape disturbances and the effect of climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W.L.

    1993-04-01

    Altering the natural disturbance regime of a landscape produces changes in the structure of that landscape as the landscape adjusts to the new disturbance regime. A computer simulation model was designed to enable analyses of the longterm changes to be expected in landscapes as their disturbance regime changes. The model, DISPATCH, is the first dynamic spatial simulation model built around a geographical information system (GIS). The model also includes a new set of programs, the r.le programs, that is the first set of programs designed for calculating landscape structure measures within a GIS. The DISPATCH model was used, to analyze the effects of human alterations of disturbance regimes and global change on landscape structure. Landscapes do not adjust quickly to these alterations based on available data. Landscapes subjected to warming or to longterm fire suppression experience a decline in patch richness, Shannon diversity, the amount of edge and contrast, but an increase in distance between patches, angular second moment (texture measure) and patch size. In contrast, landscapes subjected to cooling, the short-term effects of fire suppression, fragmentation, or traditional prescribed burning tend to respond with increasing richness, Shannon diversity, edge, and contrast, but declining distance, angular second moment, and size. The pattern of response is different at different scales, with important implications for species.

  6. Sleep habits and disturbances in Malaysian children with epilepsy.

    Science.gov (United States)

    Ong, Lai Choo; Yang, Wai Wai; Wong, Sau Wei; alSiddiq, Feizel; Khu, Yi Soon

    2010-03-01

    To compare sleep habits and disturbances between Malaysian children with epilepsy and their siblings (age range 4-18 years) and to determine the factors associated with greater sleep disturbance. The Sleep Disturbance Scale for Children (SDSC) questionnaire was completed by the primary caregiver for 92 epileptic children (mean age 11.1 years, 50 male, 42 females) and their healthy siblings (mean age 11.1 years, 47 males, 45 females). Details of sleep arrangements and illness severity were obtained. Multiple regression analysis was used to determine factors associated with high Total SDSC scores in epileptic patients. Compared with their siblings, epileptic children had significantly higher total SDSC score (difference between means 8.7, 95% confidence interval (CI) 6.4-11.1) and subscale scores in disorders of initiating and maintaining sleep (3.9, 95% CI 2.8-5.2), sleep-wake transition disorders (2.1, 95% CI 1.3-2.9), sleep-disordered breathing (0.7, 95% CI 0.3-1.1) and disorders of excessive sleepiness (1.5, 95% CI 0.6-2.4). Epileptic children had a higher prevalence of co-sleeping (73.7% vs 31.5%) and on more nights per week (difference between means 3, 95% CI 2.0-3.9) than their siblings. Higher Epilepsy Illness Severity scores were associated with higher total SDSC scores (P= 0.02). Co-sleeping was highly prevalent in children with epilepsy, who also had more sleep disturbances (especially problems with initiating and maintaining sleep and sleep-wake transition disorders) than their siblings. Epilepsy severity contributed to the sleep disturbances. Evaluation of sleep problems should form part of the comprehensive care of children with severe epilepsy.

  7. Sleep disturbances in Malaysian children with cerebral palsy.

    Science.gov (United States)

    Atmawidjaja, Raymond Warouw; Wong, Sau Wei; Yang, Wai Wai; Ong, Lai Choo

    2014-07-01

    The aim of the study was to compare the frequency and type of sleep disturbances in a group of Malaysian children aged 4 to 18 years with cerebral palsy (CP) with their nearest-age, able-bodied siblings and to identify factors associated with sleep disturbances. The study was a case-control study of 109 children with CP (61 males, 48 females; mean age 9 y, SD 3 y 11 mo, range 4-18 y) and their healthy siblings (56 males, 53 females; mean age 10 y, SD 3 y 9 mo, range 4-18 y). The Sleep Disturbances Scale for Children (SDSC) questionnaire was completed by the main caregiver. In children with CP, multiple regression analysis was be used to determine factors related to higher Total SDSC sleep scores. Ninety-seven children (89%) had spastic CP, 10 (9%) had dyskinetic CP, and two (2%) had mixed CP. Based on the Gross Motor Function Classification System (GMFSC), 34 patients (31%) were at GMFSC level I or II, 10 patients (9%) at level III, and 65 patients (60%) at level IV or V. Children with CP scored significantly higher than their siblings on Total SDSC and four SDSC subscale scores - difficulty in initiating and maintaining sleep, sleep breathing disorders, sleep-wake transition disorders, and sleep hyperhidrosis. Caregiver sleep duration of less than 7 hours (p=0.02) and caregiver sleep latency of more than 30 minutes (p=0.03) were significantly associated with higher Total SDSC scores. Co-sleeping was not a significant factor. Sleep disturbances are more common in children with CP than in their siblings. Attention should be given to caregiver sleep when evaluating sleep disturbances in children with CP as this factor was shown to be associated with higher Total SDSC scores. © 2014 Mac Keith Press.

  8. Television-viewing habits and sleep disturbance in school children.

    Science.gov (United States)

    Owens, J; Maxim, R; McGuinn, M; Nobile, C; Msall, M; Alario, A

    1999-09-01

    To investigate the relationship between specific television-viewing habits and both sleep habits and sleep disturbances in school children. The parents of 495 children in grades kindergarten through fourth grade in three public elementary schools completed two retrospective survey questionnaires, one assessing their children's sleep behaviors and the other examining television-viewing habits of both the child and the family. Sleep domains assessed included bedtime resistance, sleep onset delay, sleep duration, anxiety around sleep, parasomnias, night wakings, and daytime sleepiness. Teachers from all three schools also completed daytime sleepiness questionnaires (N = 402) for the sample. Most of the television-viewing practices examined in this study were associated with at least one type of sleep disturbance. Despite overall close monitoring of television-viewing habits, one quarter of the parents reported the presence of a television set in the child's bedroom. The television-viewing habits associated most significantly with sleep disturbance were increased daily television viewing amounts and increased television viewing at bedtime, especially in the context of having a television set in the child's bedroom. The sleep domains that appeared to be affected most consistently by television were bedtime resistance, sleep onset delay, and anxiety around sleep, followed by shortened sleep duration. The parent's threshold for defining "problem sleep behavior" in their child was also important in determining the significance of the association between sleep disturbance and television-viewing habits. Health care practitioners should be aware of the potential negative impact of television viewing at bedtime. Parents should be questioned about their children's television-viewing habits as part of general screening for sleep disturbances and as part of anticipatory guidance in regards to healthy sleep habits in children. In particular, the presence of a television set in the

  9. Animal responses to natural disturbance and climate extremes: a review

    Science.gov (United States)

    Sergio, Fabrizio; Blas, Julio; Hiraldo, Fernando

    2018-02-01

    Natural disturbances, such as droughts, fires or hurricanes, are key drivers of ecological heterogeneity and ecosystem function. The frequency and severity of these episodes is unequivocally expected to increase in the coming decades, through the concerted action of climate change and anthropogenic pressures. This will impose severe challenges for many biota through exposure to rapidly changing conditions never experienced in the preceding millennia. Thus, it is urgently needed to gain a thorough understanding of animal responses and adaptations to disturbances in order to better estimate potential future impacts. Here, we review such adjustments and find that animals may respond to disturbances through changes in: (1) behaviour, such as altered mobility, emigration, resource-switching, refuge use, suspended animation, or biotic interactions; (2) life history traits, such as survival, aging, longevity, recruitment, reproductive restraint, breeding output, phenology and bet-hedging tactics; (3) morphology, such as rapid evolution through size-dependent mortality or facultative metamorphosis; (4) physiology, such as altered body condition, pathogen prevalence and transmission, or adrenocortical modulation of stress responses to emergency conditions; (5) genetic structure, such as changes in frequency of polymorphic variants or diversity-modulation through mortality bottlenecks. Individual-level responses scale up to population and community responses, such as altered density, population dynamics, distribution, local extinction and colonization, or assemblage structure and diversity. Overall, disturbances have pervasive effects on individuals, populations and communities of vertebrates and invertebrates of all realms, biomes, continents and ecosystems. Their rapidly increasing incidence and severity will bring unique study opportunities for researchers and novel, unpredictable challenges for managers, while demanding tougher choices and more proactive crisis

  10. Pediatric Headache and Sleep Disturbance: A Comparison of Diagnostic Groups.

    Science.gov (United States)

    Rabner, Jonathan; Kaczynski, Karen J; Simons, Laura E; LeBel, Alyssa

    2018-02-01

    To examine whether sleep disturbance differs by headache diagnosis in a pediatric sample, and whether this effect remains when other factors affecting sleep are included. Primary headache disorders can be severe and disabling, impacting a child's functioning and quality of life. Many children and adolescents with chronic headaches also experience sleep difficulties, and there is likely a bidirectional relationship between headaches and sleep difficulties. Sleep problems may intensify functional and developmental difficulties in youth with chronic headaches. Despite this, research on sleep has largely been conducted only on those with migraines, with a dearth of studies including samples with tension-type headache (TTH) or new daily persistent-headache (NDPH). This retrospective chart review included 527 patients, ages 7-17 years, with a primary headache diagnosis of migraine (n = 278), TTH (n = 157), and NDPH (n = 92). Patients completed measures of disability, anxiety, and depression and their parents completed measures of sleep disturbance. Sleep disturbance was greater in patients with TTH (10.34 ± 5.94, P = .002) and NDPH (11.52 ± 6.40, P headache groups. When simultaneously examining demographic, pain-related, and emotional distress factors, older age, higher levels of disability and depression, and NDPH diagnosis were all significant predictors of greater sleep disturbance (r 2  = .25). Assessment and treatment of sleep problems in pediatric patients with chronic headache is important with several contextual and headache diagnostic factors influencing the severity of sleep disturbance. © 2017 American Headache Society.

  11. Effects of tropical montane forest disturbance on epiphytic macrolichens

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, Angel [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Prieto, Maria, E-mail: maria.prieto@urjc.es [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain); Gonzalez, Yadira [Instituto de Ecologia, Herbario HUTPL, Universidad Tecnica Particular de Loja, San Cayetano s/n, Loja (Ecuador); Aragon, Gregorio [Area de Biodiversidad y Conservacion, ESCET, Universidad Rey Juan Carlos, Mostoles, E-28933, Madrid (Spain)

    2012-12-15

    The high diversity of epiphytes typical of undisturbed montane tropical forests has been negatively affected by continuous deforestation and forest conversion to secondary vegetation. Macrolichens are an important component of these epiphytes. Because their physiology is strongly coupled to humidity and solar radiation, we hypothesized that microclimatic changes derived from forest clearing and logging can affect the diversity of these poikilohydric organisms. In southern Ecuador, we examined three types of forests according to a disturbance gradient (primary forests, secondary forests, and monospecific forests of Alnus acuminata) for the presence/absence and coverage of epiphytic macrolichens that we identified on 240 trees. We found that total richness tended to decrease when the range of the disturbance increased. The impoverishment was particularly drastic for 'shade-adapted lichens', while the richness of 'heliophytic lichens' increased in the drier conditions of secondary growth. Epiphytic composition also differed significantly among the three types of forests, and the similarity decreased when the range of the disturbance was greater. We concluded that a span of 40 years of recovery by secondary vegetation was not enough to regenerate the diversity of epiphytic macrolichens that was lost due to forest disturbances. -- Highlights: Black-Right-Pointing-Pointer Tropical montane forest disturbance drastically reduced macrolichen diversity. Black-Right-Pointing-Pointer Species loss was most severe for the 'shade-adapted lichens' because high radiation is harmful to them. Black-Right-Pointing-Pointer In secondary forests lichen diversity of native forests was not regenerated. Black-Right-Pointing-Pointer The protection of remnants of primary tropical forest might help to preserve a diverse community of epiphytic macrolichens.

  12. Sleep Disturbances in Depressed and Non-Depressed Pregnant Women

    Science.gov (United States)

    Okun, Michele L.; Kiewra, Kerith; Luther, James F.; Wisniewski, Stephen R.; Wisner, Katherine L.

    2011-01-01

    Background Sleep disturbances and symptoms of depression are common during pregnancy. Both are independent and interrelated risk factors for adverse outcomes. It is unclear the degree to which sleep differs between depressed and non-depressed pregnant women. We sought to 1), describe and compare sleep disturbances in depressed pregnant and non-depressed pregnant women, 2) determine the impact of selective serotonin reuptake inhibitors (SSRI) treatment on sleep, and 3)evaluate whether sleep at 20 weeks is associated with increased depressive symptoms and major depressive disorder (MDD) in later pregnancy. Methods Pregnant women (N = 240) were recruited in the second trimester (20 weeks gestation) and assigned to depressed (N = 59) and non-depressed (N = 181) groups based on a SCID diagnosis of major depressive disorder. The Structured Interview Guide for the Hamilton Rating Scale with Atypical Depression Supplement (SIGH-ADS) was administered at 20, 30 and 36 weeks gestation from which the sleep variables were obtained. Results Depressed women had more fragmented sleep at each assessment (p values ≤ .05). However, the frequency of insomnia symptoms was greater for depressed women only at 20 weeks gestation. SSRI use, regardless of MDD status, did significantly affect several sleep variables. Among the non-depressed women, those with short or longer sleep duration, symptoms of insomnia and long periods of nocturnal waketime had higher SIGH-ADS scores later in pregnancy (p values = sleep was more disturbed in depressed pregnant women compared to non-depressed pregnant women. At 36 weeks, sleep was disturbed regardless of depression status or SSRI use. Among the non-depressed women, disturbed sleep in conjunction with SSRI use was associated with higher depressive symptoms. PMID:21608086

  13. Anthropogenic and natural disturbances to marine benthic communities in Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Lenihan, H.; Oliver, J.S. [Moss Landing Marine Labs., CA (United States)

    1995-05-01

    Sampling and field experiments were conducted from 1975 to 1990 to test how the structure of marine benthic communities around McMurdo Station, Antarctica varied with levels of anthropogenic contaminants in marine sediments. The structure of communities (e.g., infauna density, species composition, and life history characteristics) in contaminated and uncontaminated areas were compared with the structure of communities influenced by two large-scale natural disturbances, anchor ice formation and uplift or iceberg scour. Benthic communities changed radically along a steep spatial gradient of anthropogenic hydrocarbon, metal, and PCB contamination around McMurdo Station. The heavily contaminated end of the gradient, Winter Quarters Bay, was low in infaunal and epifaunal abundance and was dominated by a few opportunistic species of polychaete worms. The edge of the heavily contaminated bay, the transition area, contained several motile polychaete species with less opportunistic life histories. Uncontaminated sedimentary habitats harbored dense tube mats of infaunal animals numerically dominated by populations of polychaete worms, crustaceans, and a large suspension feeding bivalve. These species are generally large and relatively sessile, except for several crustacean species living among the tubes. Although the community patterns around anthropogenic and natural disturbances were similar, particularly motile and opportunistic species at heavily disturbed and marginal areas, the natural disturbances cover much greater areas of the sea floor about the entire Antarctic continent. On the other hand, recovery from chemical contamination is likely to take many more decades than recovery from natural disturbances as contaminant degradation is a slow process. 77 refs., 6 figs., 5 tabs.

  14. Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial

    Science.gov (United States)

    2010-01-01

    Background Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. Methods/Design This study will evaluate the feasibility of a randomised controlled trial (RCT), exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement), and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT. Planned analysis will

  15. Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial

    Directory of Open Access Journals (Sweden)

    van Mechelen Willem

    2010-04-01

    Full Text Available Abstract Background Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks, associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. Methods/Design This study will evaluate the feasibility of a randomised controlled trial (RCT, exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement, and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT

  16. Hormonal disturbances due to severe and mild forms of congenital adrenal hyperplasia are already detectable in neonatal life

    DEFF Research Database (Denmark)

    Faurschou, Signe; Mouritsen, Annette; Johannsen, Trine H

    2015-01-01

    -hydroxyprogesterone, androstenedione, and cortisol - with genotypes in 21-hydroxylase deficiency. METHODS: The study included 62 patients with congenital adrenal hyperplasia born between 1982 and 2012 and 61 random controls born in 1985 and 2005. Patients were grouped according to mutation-based predictions of enzyme impairment...... concentrations of 17α-hydroxyprogesterone (p cortisol, p .... CONCLUSION: There were significant differences in neonatal hormonal profiles between all groups and controls. This confirms that hormonal disturbances are already detectable in both severe and mild forms of congenital adrenal hyperplasia in neonatal life....

  17. The effect of MElatonin on Depressive symptoms, Anxiety, CIrcadian and Sleep disturbances in patients after acute coronary syndrome (MEDACIS)

    DEFF Research Database (Denmark)

    Madsen, Michael Tvilling; Isbrand, Anders; Andersen, Ulla Overgaard

    2017-01-01

    , Anxiety, CIrcadian and Sleep disturbances in patients after acute coronary syndrome" trial (MEDACIS) is a multicenter, double-blinded, placebo-controlled, randomized clinical trial. A total of 240 patients with ACS and no depressive symptoms will be included in the trial for treatment with either 25 mg...... melatonin or placebo for a 12-week period. Development and severity of depressive symptoms will be evaluated using Major Depression Inventory every 2 weeks with the purpose of investigating the potential preventive effect of melatonin on depressive symptoms. DISCUSSION: Previously, only selective serotonin...

  18. Response of abyssal Copepoda Harpacticoida (Crustacea) and other meiobenthos to an artificial disturbance and its bearing on future mining for polymetallic nodules

    Science.gov (United States)

    Ahnert, Ahmed; Schriever, Gerd

    Long-term effects of an anthropogenic physical disturbance on the Harpacticoida taxocene at a deep-sea site were investigated during the course of the disturbance and recolonization (DISCOL) experiment in a manganese nodule area in the southeastern Pacific. Nineteen harpacticoid copepod families were found, contributing 9-12% to the metazoan meiofauna of the experimental area (Nematoda 72-80%). Twelve families occurred in sufficient numbers to be considered representatively sampled. Dominant are the Ameiridae (17%) followed by Ectinosomatidae, Argestidae, Tisbidae, Neobradyidae, Diosaccidae, Paranannopidae, Paramesochridae, Canthocamptidae, Cletodidae, Thalestridae and Huntemanniidae. These families are mainly distributed at random. Basic data on developmental stage composition and sex ratio of total Harpacticoida as well as vertical distribution of harpacticoid families in the sediment column are provided. Within the overall aim of the experiment, which was to assess the ecological risks of future deep-sea manganese nodule mining, we conducted multivariate community analyses based on the familial composition of the Harpacticoida assemblages immediately before and after experimental impact as well as seven years later. We were not able to detect a community response at the family level immediately after impact. An identification of the Tisbidae to species, however, revealed initial disturbance effects. After seven years we found significant differences in the assemblage composition of the directly disturbed portions of the experimental area and the secondarily disturbed areas in between, which to some extent had received blanketing from sediment plumes created during the experimental disturbance. Best discriminating families for long-term effects are the Ameiridae, Argestidae and Thalestridae. Their potential value as indicator taxa for monitoring disturbances in the deep sea is discussed, including some considerations on a cost-effective design of such monitoring

  19. A population-based survey of sleep disturbances in middle-aged women--associations with health, health related quality of life and health behavior.

    Science.gov (United States)

    Polo-Kantola, Päivi; Laine, Antti; Aromaa, Minna; Rautava, Päivi; Markkula, Juha; Vahlberg, Tero; Sillanpää, Matti

    2014-03-01

    To evaluate the prevalence of sleep disturbances and the contributing factors in middle-aged women. In a cross-sectional design of the long-term, prospective follow-up study project of 1278 families from a random population sample, the mothers of 15 year-olds were asked to fill in a questionnaire about sleep, health, health related quality of life, and health behavior. Quality of sleep was reported by 32% of women as good, 43% quite good, 12% average, 10% quite poor and 3% as poor. The most frequent sleep disturbance was awakenings in the night, which 60% of the women experienced at least once a week. Difficulty falling asleep and waking too early in the morning were reported as a weekly occurrence by 16% and 20%, respectively. Morning sleepiness was experienced by 42% and daytime sleepiness by 32%. Chronic diseases and use of medications was associated with various sleep disturbances. Both somatic and mental symptoms increased the risk for sleep disturbances. Almost one-quarter of middle-aged women is dissatisfied with their quality of sleep. Women who have chronic disease or use of medications for basic diseases often suffer from sleep disturbance, which is also associated with the health related quality of life. Further analysis of the risk factors is needed to improve the sleep health of middle-aged women. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Net primary production of a temperate deciduous forest exhibits a threshold response to increasing disturbance severity.

    Science.gov (United States)

    Stuart-Haëntjens, Ellen J; Curtis, Peter S; Fahey, Robert T; Vogel, Christoph S; Gough, Christopher M

    2015-09-01

    The global carbon (C) balance is vulnerable to disturbances that alter terrestrial C storage. Disturbances to forests occur along a continuum of severity, from low-intensity disturbance causing the mortality or defoliation of only a subset of trees to severe stand- replacing disturbance that kills all trees; yet considerable uncertainty remains in how forest production changes across gradients of disturbance intensity. We used a gradient of tree mortality in an upper Great Lakes forest ecosystem to: (1) quantify how aboveground wood net primary production (ANPP,) responds to a range of disturbance severities; and (2) identify mechanisms supporting ANPPw resistance or resilience following moderate disturbance. We found that ANPPw declined nonlinearly with rising disturbance severity, remaining stable until >60% of the total tree basal area senesced. As upper canopy openness increased from disturbance, greater light availability to the subcanopy enhanced the leaf-level photosynthesis and growth of this formerly light-limited canopy stratum, compensating for upper canopy production losses and a reduction in total leaf area index (LAI). As a result, whole-ecosystem production efficiency (ANPPw/LAI) increased with rising disturbance severity, except in plots beyond the disturbance threshold. These findings provide a mechanistic explanation for a nonlinear relationship between ANPPw, and disturbance severity, in which the physiological and growth enhancement of undisturbed vegetation is proportional to the level of disturbance until a threshold is exceeded. Our results have important ecological and management implications, demonstrating that in some ecosystems moderate levels of disturbance minimally alter forest production.

  1. Scaling disturbance instead of richness to better understand anthropogenic impacts on biodiversity.

    Directory of Open Access Journals (Sweden)

    Stephen J Mayor

    Full Text Available A primary impediment to understanding how species diversity and anthropogenic disturbance are related is that both diversity and disturbance can depend on the scales at which they are sampled. While the scale dependence of diversity estimation has received substantial attention, the scale dependence of disturbance estimation has been essentially overlooked. Here, we break from conventional examination of the diversity-disturbance relationship by holding the area over which species richness is estimated constant and instead manipulating the area over which human disturbance is measured. In the boreal forest ecoregion of Alberta, Canada, we test the dependence of species richness on disturbance scale, the scale-dependence of the intermediate disturbance hypothesis, and the consistency of these patterns in native versus exotic species and among human disturbance types. We related field observed species richness in 1 ha surveys of 372 boreal vascular plant communities to remotely sensed measures of human disturbance extent at two survey scales: local (1 ha and landscape (18 km2. Supporting the intermediate disturbance hypothesis, species richness-disturbance relationships were quadratic at both local and landscape scales of disturbance measurement. This suggests the shape of richness-disturbance relationships is independent of the scale at which disturbance is assessed, despite that local diversity is influenced by disturbance at different scales by different mechanisms, such as direct removal of individuals (local or indirect alteration of propagule supply (landscape. By contrast, predictions of species richness did depend on scale of disturbance measurement: with high local disturbance richness was double that under high landscape disturbance.

  2. Adaptive Disturbance Estimation for Offset-Free SISO Model Predictive Control

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Poulsen, Niels Kjølstad; Jørgensen, Sten Bay

    2011-01-01

    Offset free tracking in Model Predictive Control requires estimation of unmeasured disturbances or the inclusion of an integrator. An algorithm for estimation of an unknown disturbance based on adaptive estimation with time varying forgetting is introduced and benchmarked against the classical...... disturbance modelling approach, where the system description is augmented by a disturbance state. The time varying forgetting renders the new approach less sensitive to the nature of the disturbance. By simulation we demonstrate that this algorithm is advantageous in case of infrequent step disturbances...

  3. Diversity and network structure of invertebrate communities associated to Heliconia species in natural and human disturbed tropical rain forests

    Directory of Open Access Journals (Sweden)

    Julieta Benítez-Malvido

    2014-12-01

    Full Text Available We analyzed the influence of natural and anthropogenic habitat disturbance on the structure of invertebrate communities living on two species of Heliconia herbs. We compared the invertebrate community structure associated to both species growing in natural forest gaps, on road edges for H. latispatha, and in riparian vegetation for H. collinsiana. We assessed the topological structure of individual-based Heliconia–invertebrate networks. Species richness was greater in H. collinsiana inhabiting riparian vegetation but no differences were found in the diversity of invertebrates for any Heliconia species and habitat. Invertebrate abundance was greater in gaps for H. latispatha and in riparian vegetation for H. collinsiana showing a species turnover in human disturbed habitats. The invertebrate community was not randomly assembled but highly nested, revealing a structured pattern for all habitat conditions. Heliconia–invertebrate network properties appear to be maintained in human disturbed habitats, despite differences in species richness, abundance and composition and host number and quality. Our study contributes to the understanding of the structure of ecological interactions in contrasting habitats. Because they provide food and habitat for the associated fauna and several microhabitats for colonization, heliconias could be used as habitat elements for invertebrate conservation in human impacted landscapes.

  4. Effectiveness and feasibility of a cognitive-behavioral group intervention for body image disturbance in women with eating disorders.

    Science.gov (United States)

    Bhatnagar, Kelly A C; Wisniewski, Lucene; Solomon, Mindy; Heinberg, Leslie

    2013-01-01

    The present study investigated the effectiveness and feasibility of a cognitive-behavioral group intervention for the treatment of body image disturbance in women with eating disorders. The study used a multiple-baseline design and enrolled 38 participants with a range of eating disorders. The intervention targeted attitudinal and behavioral components of body image disturbance using psychoeducation, self-monitoring, systematic desensitization, and cognitive restructuring. Primary outcomes included multidimensional body image assessment (effectiveness) and treatment adherence and satisfaction (feasibility). Participants undergoing manualized group treatment reported significantly less body image disturbance than participants randomized to a waitlist control condition. However, differences disappeared after both groups had been through intervention. Participants also reported less depression and eating disorder pathology from baseline to posttreatment, however this difference was not considered statistically significant. Feasibility outcomes suggest the intervention was well received and highly acceptable to participants. Findings emphasize the importance of adding an evidence-based body image component to standard eating disorder treatment. © 2012 Wiley Periodicals, Inc.

  5. Increased sensitivity to climate change in disturbed ecosystems

    DEFF Research Database (Denmark)

    Kroël-Dulay, György; Ransijn, Johannes; Schmidt, Inger Kappel

    2015-01-01

    this relationship for the perturbation of climate change. Here we show that vegetation (abundance, species richness and species composition) across seven European shrublands is quite resistant to moderate experimental warming and drought, and responsiveness is associated with the dynamic state of the ecosystem......Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports......, with recently disturbed sites responding to treatments. Furthermore, most of these responses are not rapid (2-5 years) but emerge over a longer term (7-14 years). These results suggest that successional state influences the sensitivity of ecosystems to climate change, and that ecosystems recovering from...

  6. Interplanetary shock waves and the structure of solar wind disturbances

    Science.gov (United States)

    Hundhausen, A. J.

    1972-01-01

    Observations and theoretical models of interplanetary shock waves are reviewed, with emphasis on the large-scale characteristics of the associated solar wind disturbances and on the relationship of these disturbances to solar activity. The sum of observational knowledge indicates that shock waves propagate through the solar wind along a broad, roughly spherical front, ahead of plasma and magnetic field ejected from solar flares. Typically, the shock front reaches 1 AU about two days after its flare origin, and is of intermediate strength. Not all large flares produce observable interplanetary shock waves; the best indicator of shock production appears to be the generation of both type 2 and type 4 radio bursts by a flare. Theoretical models of shock propagation in the solar wind can account for the typically observed shock strength, transit time, and shape.

  7. Modified active disturbance rejection control for time-delay systems.

    Science.gov (United States)

    Zhao, Shen; Gao, Zhiqiang

    2014-07-01

    Industrial processes are typically nonlinear, time-varying and uncertain, to which active disturbance rejection control (ADRC) has been shown to be an effective solution. The control design becomes even more challenging in the presence of time delay. In this paper, a novel modification of ADRC is proposed so that good disturbance rejection is achieved while maintaining system stability. The proposed design is shown to be more effective than the standard ADRC design for time-delay systems and is also a unified solution for stable, critical stable and unstable systems with time delay. Simulation and test results show the effectiveness and practicality of the proposed design. Linear matrix inequality (LMI) based stability analysis is provided as well. © 2013 ISA Published by ISA All rights reserved.

  8. Sleep Disturbance in Bipolar Disorder Across the Lifespan.

    Science.gov (United States)

    Harvey, Allison G; Talbot, Lisa S; Gershon, Anda

    2009-06-01

    The aim of this article is to highlight the importance of the sleep-wake cycle in children, adolescents, and adults with bipolar disorder. After reviewing the evidence that has accrued to date on the nature and severity of the sleep disturbance experienced, we document the importance of sleep for quality of life, risk for relapse, affective functioning, cognitive functioning, health (sleep disturbance is implicated in obesity, poor diet, and inadequate exercise), impulsivity, and risk taking. We argue that sleep may be critically important in the complex multifactorial cause of interepisode dysfunction, adverse health outcomes, and relapse. An agenda for future research is presented that includes improving the quality of sleep measures and controlling for the impact of bipolar medications.

  9. Sleep disturbances after fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Krenk, L; Jennum, P; Kehlet, H

    2012-01-01

    on the fourth postoperative night. There was no association between opioid use, pain scores, and inflammatory response with a disturbed sleep pattern. CONCLUSIONS: /st>Despite ultra-short LOS and provision of spinal anaesthesia with multimodal opioid-sparing analgesia, REM sleep was almost eliminated......BACKGROUND: /st>Major surgery is followed by pronounced sleep disturbances after traditional perioperative care potentially leading to prolonged recovery. The aim was to evaluate the rapid eye movement (REM) sleep duration and sleep architecture before and after fast-track hip and knee replacement......, and on the fourth postoperative night at home. Sleep staging was performed according to the American Academy of Sleep Medicine manual. Opioid use, pain, and inflammatory response (C-reactive protein) were also evaluated. RESULTS: /st>The mean LOS was 1.5 (1-2) days. The mean REM sleep time decreased from a mean...

  10. Unique Migraine Subtypes, Rare Headache Disorders, and Other Disturbances.

    Science.gov (United States)

    Goadsby, Peter J

    2015-08-01

    The medical aphorism that common things happen commonly makes unique (and less common) migraine subtypes especially appropriate to review for the general neurologist. This article also identifies some rare headache disorders and other disturbances, and offers strategies to manage them. This article discusses migraine with brainstem aura, which is troublesome clinically and has had a change in terminology in the International Classification of Headache Disorders, Third Edition, beta version (ICHD-3 beta), and hemiplegic migraine, which is also troublesome in practice. The rare headache disorder hypnic headache and the exploding head syndrome are also discussed. When hypnic headache is recognized, it is eminently treatable, while exploding head syndrome is a benign condition with no reported consequences. Unique migraine subtypes, rare headache disorders, and other disturbances present to neurologists. When recognized, they can often be managed very well, which offers significant benefits to patients and practice satisfaction to neurologists.

  11. Laparoscopic cholecystectomy causes less sleep disturbance than open abdominal surgery

    DEFF Research Database (Denmark)

    Gögenur, I; Rosenberg-Adamsen, S; Kiil, C

    2001-01-01

    BACKGROUND: The aim of this study was to examine subjective sleep quality before and after laparoscopic vs open abdominal surgery. METHODS: Twelve patients undergoing laparoscopic cholecystectomy and 15 patients undergoing laparotomy were evaluated with the aid of a sleep questionnaire from 4 days...... before until 4 weeks after surgery. RESULTS: Following laparoscopic surgery, total sleep time increased during the 1st week after the operation compared with preoperative values (p = 0.02), whereas sleep duration during weeks 2, 3, and 4 did not differ from the times reported preoperatively. Following...... laparotomy, sleep duration increased during the 1st, 3rd, and 4th weeks after the operation compared with preoperative values (p sleep disturbance, with significantly more sleep during the daytime compared with preoperative values; the disturbance...

  12. Quantum Errors and Disturbances: Response to Busch, Lahti and Werner

    Directory of Open Access Journals (Sweden)

    David Marcus Appleby

    2016-05-01

    Full Text Available Busch, Lahti and Werner (BLW have recently criticized the operator approach to the description of quantum errors and disturbances. Their criticisms are justified to the extent that the physical meaning of the operator definitions has not hitherto been adequately explained. We rectify that omission. We then examine BLW’s criticisms in the light of our analysis. We argue that, although the BLW approach favour (based on the Wasserstein two-deviation has its uses, there are important physical situations where an operator approach is preferable. We also discuss the reason why the error-disturbance relation is still giving rise to controversies almost a century after Heisenberg first stated his microscope argument. We argue that the source of the difficulties is the problem of interpretation, which is not so wholly disconnected from experimental practicalities as is sometimes supposed.

  13. Disturbance Accommodating Adaptive Control with Application to Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2012-01-01

    Adaptive control techniques are well suited to applications that have unknown modeling parameters and poorly known operating conditions. Many physical systems experience external disturbances that are persistent or continually recurring. Flexible structures and systems with compliance between components often form a class of systems that fail to meet standard requirements for adaptive control. For these classes of systems, a residual mode filter can restore the ability of the adaptive controller to perform in a stable manner. New theory will be presented that enables adaptive control with accommodation of persistent disturbances using residual mode filters. After a short introduction to some of the control challenges of large utility-scale wind turbines, this theory will be applied to a high-fidelity simulation of a wind turbine.

  14. Minimum disturbance rewards with maximum possible classical correlations

    Science.gov (United States)

    Pande, Varad R.; Shaji, Anil

    2017-07-01

    Weak measurements done on a subsystem of a bipartite system having both classical and nonClassical correlations between its components can potentially reveal information about the other subsystem with minimal disturbance to the overall state. We use weak quantum discord and the fidelity between the initial bipartite state and the state after measurement to construct a cost function that accounts for both the amount of information revealed about the other system as well as the disturbance to the overall state. We investigate the behaviour of the cost function for families of two qubit states and show that there is an optimal choice that can be made for the strength of the weak measurement.

  15. Disturbance observer based current controller for vector controlled IM drives

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Dal, Mehmet

    2008-01-01

    In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...... induction motor (IM) drives. The control design, based on synchronously rotating d-q frame model of the machine, has a simple structure that combines the proportional portion of a conventional PI control and output of the observer. The observer is predicted to estimate the disturbances caused by parameters...... change in current control loop and, also to remove undesired cross coupling existing between components of the stator current. The observer uses the measured stator currents and estimated PWM voltages, and produces a disturbance signal with a low pass filter. The proposed control scheme reduces cross...

  16. Disturbance, life history, and optimal management for biodiversity

    Science.gov (United States)

    Guo, Q.

    2003-01-01

    Both frequency and intensity of disturbances in many ecosystems have been greatly enhanced by increasing human activities. As a consequence, the short-lived plant species including many exotics might have been dramatically increased in term of both richness and abundance on our planet while many long-lived species might have been lost. Such conclusions can be drawn from broadly observed successional cycles in both theoretical and empirical studies. This article discusses two major issues that have been largely overlooked in current ecosystem management policies and conservation efforts, i.e., life history constraints and future global warming trends. It also addresses the importance of these two factors in balancing disturbance frequency and intensity for optimal biodiversity maintenance and ecosystem management.

  17. Evolution of extratropical cyclones during disturbed geomagnetic conditions

    Science.gov (United States)

    Karakhanyan, A. A.; Molodyk, S. I.

    2017-09-01

    An analysis of temperature changes in warm and cold air masses of extratropical cyclones in both hemispheres with their movement during geomagnetic disturbances at the minimum of solar activity was performed. The location and movement of air masses of cyclones was determined by thermobaric maps at the 500 hPa level. In the conditions of a classical cyclogenesis, a warm air mass cools from day to day, while the cold air mass warms up. During geomagnetic disturbances, favorable conditions for increasing intensity and cyclone lifetime are formed, i.e., in a warm air mass, the temperature increases at heights lower than 300 hPa, while a cold air mass warms up more slowly. The distributions of the temperature of air masses of extratropical cyclones were shown to change due to the changes in geomagnetic activity.

  18. Alexia for arithmetical signs. A cause of disturbed calculation.

    Science.gov (United States)

    Ferro, J M; Silveira Botelho, M A

    1980-03-01

    Asymbolic acalculia is a variety of acalculia characterized by a failure to differentiate the arithmetical symbols. Two patients presenting this disturbance as the only source of their calculating errors are reported. Neither aphasia nor visuo-verbal disconnection could explain the failure to identify the arithmetical signs. This defect is interpreted as an alexia for this particular semiotic system, the arithmetical signs being stripped of their names and of the corresponding computational rules.

  19. Speckle perception and disturbance limit in laser based projectors

    Science.gov (United States)

    Verschaffelt, Guy; Roelandt, Stijn; Meuret, Youri; Van den Broeck, Wendy; Kilpi, Katriina; Lievens, Bram; Jacobs, An; Janssens, Peter; Thienpont, Hugo

    2016-04-01

    We investigate the level of speckle that can be tolerated in a laser cinema projector. For this purpose, we equipped a movie theatre room with a prototype laser projector. A group of 186 participants was gathered to evaluate the speckle perception of several, short movie trailers in a subjective `Quality of Experience' experiment. This study is important as the introduction of lasers in projection systems has been hampered by the presence of speckle in projected images. We identify a speckle disturbance threshold by statistically analyzing the observers' responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. As is also discussed in [Verschaffelt et al., Scientific Reports 5, art. nr. 14105, 2015] we find that, for moving images, the speckle becomes disturbing if the speckle contrast becomes larger than 6.9% for the red, 6.0% for the green, and 4.8% for the blue primary colors of the projector, whereas for still images the speckle detection threshold is about 3%. As we could not independently tune the speckle contrast of each of the primary colors, this speckle disturbance limit seems to be determined by the 6.9% speckle contrast of the red color as this primary color contains the largest amount of speckle. The speckle disturbance limit for movies thus turns out to be substantially larger than that for still images, and hence is easier to attain.

  20. Disturbance decouples biogeochemical cycles across forests of the southeastern US

    Science.gov (United States)

    Ashley D. Keiser; Jennifer D. Knoepp; Mark A. Bradford

    2016-01-01

    Biogeochemical cycles are inherently linked through the stoichiometric demands of the organisms that cycle the elements. Landscape disturbance can alter element availability and thus the rates of biogeochemical cycling. Nitrification is a fundamental biogeochemical process positively related to plant productivity and nitrogen loss from soils to aquatic systems, and the...