Sample records for adequately powered randomized

  1. Revisiting sample size: are big trials the answer?

    PubMed

    Lurati Buse, Giovanna A L; Botto, Fernando; Devereaux, P J

    2012-07-18

    The superiority of the evidence generated in randomized controlled trials over observational data is not only conditional to randomization. Randomized controlled trials require proper design and implementation to provide a reliable effect estimate. Adequate random sequence generation, allocation implementation, analyses based on the intention-to-treat principle, and sufficient power are crucial to the quality of a randomized controlled trial. Power, or the probability of the trial to detect a difference when a real difference between treatments exists, strongly depends on sample size. The quality of orthopaedic randomized controlled trials is frequently threatened by a limited sample size. This paper reviews basic concepts and pitfalls in sample-size estimation and focuses on the importance of large trials in the generation of valid evidence.

  2. The Power of the Test for Treatment Effects in Three-Level Block Randomized Designs

    ERIC Educational Resources Information Center

    Konstantopoulos, Spyros

    2008-01-01

    Experiments that involve nested structures may assign treatment conditions either to subgroups (such as classrooms) or individuals within subgroups (such as students). The design of such experiments requires knowledge of the intraclass correlation structure to compute the sample sizes necessary to achieve adequate power to detect the treatment…

  3. Slow-release L-Cysteine (Acetium®) Lozenge Is an Effective New Method in Smoking Cessation. A Randomized, Double-blind, Placebo-controlled Intervention.

    PubMed

    Syrjänen, Kari; Eronen, Katja; Hendolin, Panu; Paloheimo, Lea; Eklund, Carita; Bäckström, Anna; Suovaniemi, Osmo

    2017-07-01

    Because of the major health problems and annual economic burden caused by cigarette smoking, effective new tools for smoking intervention are urgently needed. Our previous randomized controlled trial (RCT) provided promising results on the efficacy of slow-release L-cysteine lozenge in smoking intervention, but the study was not adequately powered. To confirm in an adequately-powered study the results of the previous RCT implicating that effective elimination of acetaldehyde in saliva by slow-release L-cysteine (Acetium® lozenge, Biohit Oyj, Helsinki), would assist in smoking cessation by reducing acetaldehyde-enhanced nicotine addiction. On this matter, we undertook a double-blind, randomized, placebo-controlled trial comparing Acetium® lozenge and placebo in smoking intervention. A cohort of 1,998 cigarette smokers were randomly allocated to intervention (n=996) and placebo arms (n=1,002). At baseline, smoking history was recorded by a questionnaire, with nicotine dependence testing according to the Fagerström scale (FTND). The subjects used smoking diary recording the daily numbers of cigarettes, lozenges and subjective sensations of smoking. The data were analysed separately for point prevalence of abstinence (PPA) and prolonged abstinence (PA) endpoints. Altogether, 753 study subjects completed the trial per protocol (PP), 944 with violations (mITT), and the rest (n=301) were lost to follow-up (LTF). During the 6-month intervention, 331 subjects stopped smoking; 181 (18.2%) in the intervention arm and 150 (15.0%) in the placebo arm (OR=1.43; 95%CI=1.09-1.88); p=0.010). In the PP group, 170 (45.3%) quitted smoking in the intervention arm compared to 134 (35.4%) in the placebo arm (OR=1.51, 95%CI=1.12-2.02; p=0.006). In multivariate (Poisson regression) model, decreased level of smoking pleasure (p=0.010) and "smoking sensations changed" were powerful independent predictors of quit events (IRR=12.01; 95%CI=1.5-95.6). Acetium® lozenge, herein confirmed in an adequately powered study to be an effective means to aid smoking quit, represents a major breakthrough in the development of smoking intervention methods, because slow-release L-cysteine is non-toxic, with no side-effects or limitations of use. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  4. The Consolidated Standards of Reporting Trials (CONSORT) Statement applied to allergen-specific immunotherapy with inhalant allergens: a Global Allergy and Asthma European Network (GA(2)LEN) article.

    PubMed

    Bousquet, Philippe J; Calderón, Moisés A; Demoly, Pascal; Larenas, Désirée; Passalacqua, Giovanni; Bachert, Claus; Brozek, Jan; Canonica, G Walter; Casale, Thomas; Fonseca, Joao; Dahl, Ronald; Durham, Stephen R; Merk, Hans; Worm, Margitta; Wahn, Ulrich; Zuberbier, Torsten; Schünemann, Holger J; Bousquet, Jean

    2011-01-01

    Randomized trials provide evidence to inform treatment decisions. The Consolidated Standards of Reporting Trials (CONSORT) Statement is a set of recommendations for the reporting of trials. We sought to assess the quality of reporting allergen-specific immunotherapy trials according to CONSORT criteria. The reporting of the procedure, randomization, dropouts, strict conduct of intention-to-treat (ITT) analysis, and sample size calculation according to CONSORT were assessed in the 46 subcutaneous and 48 sublingual immunotherapy (SLIT) blind, placebo-controlled randomized trials published between 1996 and 2009 in English. One subcutaneous immunotherapy (2.2%) and 3 SLIT (6.6%) trials met CONSORT Statement criteria. These were used for the registration of sublingual tablets to the European Medicines Agency. In subcutaneous immunotherapy, 16 (35%) studies reported a CONSORT flow chart, and 12 (26%) provided a description of dropouts. Adequate randomization was reported in 9 (35%) studies, and incomplete randomization was reported in 15 (33%). Power analysis was reported in 15 (33%) studies. In SLIT, 20 (42%) studies reported a CONSORT flow chart, and 16 (32%) a description of dropouts. ITT analysis was carried out in 1 (2.2%) SLIT study, and a modified ITT analysis was used in 1 (2.2%) subcutaneous immunotherapy study and 2 (4.4%) SLIT studies. Adequate randomization was reported in 6 (12%) studies, and incomplete randomization was reported in 16 (32%). Power analysis was reported in 15 (27%) studies. As in other areas of medicine, the quality of reporting of most immunotherapy trials is low, and only 4.2% of SLIT randomized controlled trials met all of the criteria of the CONSORT Statement. Use of the CONSORT criteria should be encouraged. Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  5. Statistical power in parallel group point exposure studies with time-to-event outcomes: an empirical comparison of the performance of randomized controlled trials and the inverse probability of treatment weighting (IPTW) approach.

    PubMed

    Austin, Peter C; Schuster, Tibor; Platt, Robert W

    2015-10-15

    Estimating statistical power is an important component of the design of both randomized controlled trials (RCTs) and observational studies. Methods for estimating statistical power in RCTs have been well described and can be implemented simply. In observational studies, statistical methods must be used to remove the effects of confounding that can occur due to non-random treatment assignment. Inverse probability of treatment weighting (IPTW) using the propensity score is an attractive method for estimating the effects of treatment using observational data. However, sample size and power calculations have not been adequately described for these methods. We used an extensive series of Monte Carlo simulations to compare the statistical power of an IPTW analysis of an observational study with time-to-event outcomes with that of an analysis of a similarly-structured RCT. We examined the impact of four factors on the statistical power function: number of observed events, prevalence of treatment, the marginal hazard ratio, and the strength of the treatment-selection process. We found that, on average, an IPTW analysis had lower statistical power compared to an analysis of a similarly-structured RCT. The difference in statistical power increased as the magnitude of the treatment-selection model increased. The statistical power of an IPTW analysis tended to be lower than the statistical power of a similarly-structured RCT.

  6. Measuring Behavioral Outcomes Associated with Comprehensive Character Education Programs: A Practical Approach to Using Fewer Schools in School-Randomized Controlled Trials While Maintaining Adequate Statistical Power

    ERIC Educational Resources Information Center

    Holtzapple, Carol K.

    2011-01-01

    Character education programs support the development of positive character traits in children and adults. Effective violence prevention programs improve pro-social competencies and reduce negative behaviors in students by enhancing protective factors (strong bonds with teachers; clear rules of conduct that are consistently enforced) and targeting…

  7. Increased statistical power with combined independent randomization tests used with multiple-baseline design.

    PubMed

    Tyrrell, Pascal N; Corey, Paul N; Feldman, Brian M; Silverman, Earl D

    2013-06-01

    Physicians often assess the effectiveness of treatments on a small number of patients. Multiple-baseline designs (MBDs), based on the Wampold-Worsham (WW) method of randomization and applied to four subjects, have relatively low power. Our objective was to propose another approach with greater power that does not suffer from the time requirements of the WW method applied to a greater number of subjects. The power of a design that involves the combination of two four-subject MBDs was estimated using computer simulation and compared with the four- and eight-subject designs. The effect of a delayed linear response to treatment on the power of the test was also investigated. Power was found to be adequate (>80%) for a standardized mean difference (SMD) greater than 0.8. The effect size associated with 80% power from combined tests was smaller than that of the single four-subject MBD (SMD=1.3) and comparable with the eight-subject MBD (SMD=0.6). A delayed linear response to the treatment resulted in important reductions in power (20-35%). By combining two four-subject MBD tests, an investigator can detect better effect sizes (SMD=0.8) and be able to complete a comparatively timelier and feasible study. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Test-treatment RCTs are susceptible to bias: a review of the methodological quality of randomized trials that evaluate diagnostic tests.

    PubMed

    Ferrante di Ruffano, Lavinia; Dinnes, Jacqueline; Sitch, Alice J; Hyde, Chris; Deeks, Jonathan J

    2017-02-24

    There is a growing recognition for the need to expand our evidence base for the clinical effectiveness of diagnostic tests. Many international bodies are calling for diagnostic randomized controlled trials to provide the most rigorous evidence of impact to patient health. Although these so-called test-treatment RCTs are very challenging to undertake due to their methodological complexity, they have not been subjected to a systematic appraisal of their methodological quality. The extent to which these trials may be producing biased results therefore remains unknown. We set out to address this issue by conducting a methodological review of published test-treatment trials to determine how often they implement adequate methods to limit bias and safeguard the validity of results. We ascertained all test-treatment RCTs published 2004-2007, indexed in CENTRAL, including RCTs which randomized patients to diagnostic tests and measured patient outcomes after treatment. Tests used for screening, monitoring or prognosis were excluded. We assessed adequacy of sequence generation, allocation concealment and intention-to-treat, appropriateness of primary analyses, blinding and reporting of power calculations, and extracted study characteristics including the primary outcome. One hundred three trials compared 105 control with 119 experimental interventions, and reported 150 primary outcomes. Randomization and allocation concealment were adequate in 57 and 37% of trials. Blinding was uncommon (patients 5%, clinicians 4%, outcome assessors 21%), as was an adequate intention-to-treat analysis (29%). Overall 101 of 103 trials (98%) were at risk of bias, as judged using standard Cochrane criteria. Test-treatment trials are particularly susceptible to attrition and inadequate primary analyses, lack of blinding and under-powering. These weaknesses pose much greater methodological and practical challenges to conducting reliable RCT evaluations of test-treatment strategies than standard treatment interventions. We suggest a cautious approach that first examines whether a test-treatment intervention can accommodate the methodological safeguards necessary to minimize bias, and highlight that test-treatment RCTs require different methods to ensure reliability than standard treatment trials. Please see the companion paper to this article: http://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-016-0286-0 .

  9. Chelation therapy to treat atherosclerosis, particularly in diabetes: Is it time to reconsider?

    PubMed Central

    Lamas, Gervasio A; Ergui, Ian

    2016-01-01

    Summary Reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes. The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years. These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. PMID:27149141

  10. Noninvasive Ventilatory Correction in Patients With Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

    PubMed

    Tsivgoulis, Georgios; Alexandrov, Andrei V; Katsanos, Aristeidis H; Barlinn, Kristian; Mikulik, Robert; Lambadiari, Vaia; Bonakis, Anastasios; Alexandrov, Anne W

    2017-08-01

    Even though current guidelines suggest that noninvasive ventilatory correction (NIVC) could be considered for acute ischemic stroke patients with obstructive sleep apnea, available evidence is conflicting, with no adequately powered randomized clinical trial being available to date. We conducted a systematic review and meta-analysis of all available literature data evaluating the effect of NIVC on neurological improvement (based on decrease in National Institutes of Health Stroke Scale score), vascular events (recurrent stroke, transient ischemic attack, myocardial infarction and unstable angina), and mortality during the follow-up period. We identified 4 randomized clinical trials and 1 prospectively matched observational cohort, comprising a total of 389 patients (59.8% males, mean age: 64.4 years). The risk of both performance and detection bias was considered high in most of the included randomized clinical trials because of the lack of blinding in participants, personnel and/or outcome assessors. The mean decrease in National Institutes of Health Stroke Scale scores during the first (≤30) days of acute ischemic stroke was found to be greater in NIVC-treated patients in comparison to controls (standardized mean difference, 0.38; 95% confidence interval, 0.11-0.66; P =0.007). However, no significant differences were detected between NIVC-treated acute ischemic stroke patients and controls on both the risk of vascular events (risk ratio, 0.53; 95% confidence interval, 0.25-1.14; P =0.11) and mortality (risk ratio, 0.71; 95% confidence interval, 0.37-1.36; P =0.30). No evidence of heterogeneity ( I 2 =0%; P for Cochran Q>0.50) or publication bias were detected in all analyses. NIVC seems to be associated with greater short-term neurological improvement in acute ischemic stroke patients with obstructive sleep apnea. This finding deserves further investigation within the settings of an adequately powered, sham-control, randomized clinical trial. © 2017 American Heart Association, Inc.

  11. High-order random Raman lasing in a PM fiber with ultimate efficiency and narrow bandwidth

    PubMed Central

    Babin, Sergey A.; Zlobina, Ekaterina A.; Kablukov, Sergey I.; Podivilov, Evgeniy V.

    2016-01-01

    Random Raman lasers attract now a great deal of attention as they operate in non-active turbid or transparent scattering media. In the last case, single mode fibers with feedback via Rayleigh backscattering generate a high-quality unidirectional laser beam. However, such fiber lasers have rather poor spectral and polarization properties, worsening with increasing power and Stokes order. Here we demonstrate a linearly-polarized cascaded random Raman lasing in a polarization-maintaining fiber. The quantum efficiency of converting the pump (1.05 μm) into the output radiation is almost independent of the Stokes order, amounting to 79%, 83%, and 77% for the 1st (1.11 μm), 2nd (1.17 μm) and 3rd (1.23 μm) order, respectively, at the polarization extinction ratio >22 dB for all orders. The laser bandwidth grows with increasing order, but it is almost independent of power in the 1–10 W range, amounting to ~1, ~2 and ~3 nm for orders 1–3, respectively. So, the random Raman laser exhibits no degradation of output characteristics with increasing Stokes order. A theory adequately describing the unique laser features has been developed. Thus, a full picture of the cascaded random Raman lasing in fibers is shown. PMID:26940082

  12. Follow-up of colorectal cancer patients after resection with curative intent-the GILDA trial.

    PubMed

    Grossmann, Erik M; Johnson, Frank E; Virgo, Katherine S; Longo, Walter E; Fossati, Rolando

    2004-01-01

    Surgery remains the primary treatment of colorectal cancer. Data are lacking to delineate the optimal surveillance strategy following resection. A large-scale multi-center European study is underway to address this issue (Gruppo Italiano di Lavoro per la Diagnosi Anticipata-GILDA). Following primary surgery with curative intent, stratification, and randomization at GILDA headquarters, colon cancer patients are then assigned to a more intensive or less intensive surveillance regimen. Rectal cancer patients undergoing curative resection are similarly randomized, with their follow-up regimens placing more emphasis on detection of local recurrence. Target recruitment for the study will be 1500 patients to achieve a statistical power of 80% (assuming an alpha of 0.05 and a hazard-rate reduction of >24%). Since the trial opened in 1998, 985 patients have been randomized from 41 centers as of February 2004. There were 496 patients randomized to the less intensive regimens, and 489 randomized to the more intensive regimens. The mean duration of follow-up is 14 months. 75 relapses (15%) and 32 deaths (7%) had been observed in the two more intensive follow-up arms, while 64 relapses (13%) and 24 deaths (5%) had been observed in the two less intensive arms as of February 2004. This trial should provide the first evidence based on an adequately powered randomized trial to determine the optimal follow-up strategy for colorectal cancer patients. This trial is open to US centers, and recruitment continues.

  13. Therapy of stress (takotsubo) cardiomyopathy: present shortcomings and future perspectives.

    PubMed

    Brunetti, Natale Daniele; Santoro, Francesco; De Gennaro, Luisa; Correale, Michele; Kentaro, Hayashi; Gaglione, Antonio; Di Biase, Matteo

    2016-09-01

    Several therapeutic options are available for the treatment of the acute phase of stress cardiomyopathy, pharmacological (β-blockers, diuretics, anticoagulants, antiarrhythmics, noncatecholamine inotropics [levosimendan]), and nonpharmacological (intra-aortic balloon pumping, extracorporeal membrane oxygenation), according to the wide possible clinical presentation and course of the disease. However, there is a gap in evidence, and very few data come from randomized and adequately powered studies. Some evidence supports the use of β-blockers, in particular with a short half-life, in the case of left ventricular outflow tract obstruction, and angiotensin-converting enzyme inhibitors in secondary prevention. Future perspectives include the study of genetic basis of stress cardiomyopathy, role of miRNA and neurovegetative modulation. Randomized studies, however, are surely warranted.

  14. First "glass" education: telementored cardiac ultrasonography using Google Glass- a pilot study.

    PubMed

    Russell, Patrick M; Mallin, Michael; Youngquist, Scott T; Cotton, Jennifer; Aboul-Hosn, Nael; Dawson, Matt

    2014-11-01

    The objective of this study was to determine the feasibility of telementored instruction in bedside ultrasonography (US) using Google Glass. The authors sought to examine whether first-time US users could obtain adequate parasternal long axis (PSLA) views to approximate ejection fraction (EF) using Google Glass telementoring. This was a prospective, randomized, single-blinded study. Eighteen second-year medical students were randomized into three groups and tasked with obtaining PSLA cardiac imaging. Group A received real-time telementored education through Google Glass via Google Hangout from a remotely located expert. Group B received bedside education from the same expert. Group C represented the control and received no instruction. Each subject was given 3 minutes to obtain a best PSLA cardiac imaging using a portable GE Vscan. Image clips obtained by each subject were stored. A second expert, blinded to instructional mode, evaluated images for adequacy and assigned an image quality rating on a 0 to 10 scale. Group A was able to obtain adequate images six out of six times (100%) with a median image quality rating of 7.5 (interquartile range [IQR] = 6 to 10) out of 10. Group B was also able to obtain adequate views six out of six times (100%), with a median image quality rating of 8 (IQR = 7 to 9). Group C was able to obtain adequate views one out of six times (17%), with a median image quality of 0 (IQR = 0 to 2). There were no statistically significant differences between Group A and Group B in the achievement of adequate images for E-point septal separation measurement or in image quality. In this pilot/feasibility study, novice US users were able to obtain adequate imaging to determine a healthy patient's EF through telementored education using Google Glass. These preliminary data suggest telementoring as an adequate means of medical education in bedside US. This conclusion will need to be validated with larger, more powerful studies including evaluation of pathologic findings and varying body habitus among models. © 2014 by the Society for Academic Emergency Medicine.

  15. Lung VITAL: Rationale, design, and baseline characteristics of an ancillary study evaluating the effects of vitamin D and/or marine omega-3 fatty acid supplements on acute exacerbations of chronic respiratory disease, asthma control, pneumonia and lung function in adults

    PubMed Central

    Gold, Diane R; Litonjua, Augusto A.; Carey, Vincent J.; Manson, JoAnn E.; Buring, Julie E; Lee, I-Min; Gordon, David; Walter, Joseph; Friedenberg, Georgina; Hankinson, John L; Copeland, Trisha; Luttmann-Gibson, Heike

    2016-01-01

    Laboratory and observational research studies suggest that vitamin D and marine omega-3 fatty acids may reduce risk for pneumonia, acute exacerbations of respiratory diseases including chronic obstructive lung disease (COPD) or asthma, and decline of lung function, but prevention trials with adequate dosing, adequate power, and adequate time to follow-up are lacking. The ongoing Lung VITAL study is taking advantage of a large clinical trial—the VITamin D and OmegA-3 TriaL (VITAL)—to conduct the first major evaluation of the influences of vitamin D and marine omega-3 fatty acid supplementation on pneumonia risk, respiratory exacerbation episodes, asthma control and lung function in adults. VITAL is a 5-year U.S.-wide randomized, double-blind, placebo-controlled, 2×2 factorial trial of supplementation with vitamin D3 ([cholecalciferol], 2000 IU/day) and marine omega-3 FA (Omacor® fish oil, eicosapentaenoic acid [EPA] +docosahexaenoic acid [DHA], 1 g/day) for primary prevention of CVD and cancer among men and women, at baseline aged ≥50 and ≥55, respectively, with 5107 African Americans. In a subset of 1973 participants from 11 urban U.S. centers, lung function is measured before and two years after randomization. Yearly follow-up questionnaires assess incident pneumonia in the entire randomized population, and exacerbations of respiratory disease, asthma control and dyspnea in a subpopulation of 4314 randomized participants enriched, as shown in presentation of baseline characteristics, for respiratory disease, respiratory symptoms, and history of cigarette smoking. Self-reported pneumonia hospitalization will be confirmed by medical record review, and exacerbations will be confirmed by Center for Medicare and Medicaid Services data review. PMID:26784651

  16. Lung VITAL: Rationale, design, and baseline characteristics of an ancillary study evaluating the effects of vitamin D and/or marine omega-3 fatty acid supplements on acute exacerbations of chronic respiratory disease, asthma control, pneumonia and lung function in adults.

    PubMed

    Gold, Diane R; Litonjua, Augusto A; Carey, Vincent J; Manson, JoAnn E; Buring, Julie E; Lee, I-Min; Gordon, David; Walter, Joseph; Friedenberg, Georgina; Hankinson, John L; Copeland, Trisha; Luttmann-Gibson, Heike

    2016-03-01

    Laboratory and observational research studies suggest that vitamin D and marine omega-3 fatty acids may reduce risk for pneumonia, acute exacerbations of respiratory diseases including chronic obstructive lung disease (COPD) or asthma, and decline of lung function, but prevention trials with adequate dosing, adequate power, and adequate time to follow-up are lacking. The ongoing Lung VITAL study is taking advantage of a large clinical trial-the VITamin D and OmegA-3 TriaL (VITAL)--to conduct the first major evaluation of the influences of vitamin D and marine omega-3 fatty acid supplementation on pneumonia risk, respiratory exacerbation episodes, asthma control and lung function in adults. VITAL is a 5-year U.S.-wide randomized, double-blind, placebo-controlled, 2 × 2 factorial trial of supplementation with vitamin D3 ([cholecalciferol], 2000 IU/day) and marine omega-3 FA (Omacor® fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA], 1g/day) for primary prevention of CVD and cancer among men and women, at baseline aged ≥50 and ≥55, respectively, with 5107 African Americans. In a subset of 1973 participants from 11 urban U.S. centers, lung function is measured before and two years after randomization. Yearly follow-up questionnaires assess incident pneumonia in the entire randomized population, and exacerbations of respiratory disease, asthma control and dyspnea in a subpopulation of 4314 randomized participants enriched, as shown in presentation of baseline characteristics, for respiratory disease, respiratory symptoms, and history of cigarette smoking. Self-reported pneumonia hospitalization will be confirmed by medical record review, and exacerbations will be confirmed by Center for Medicare and Medicaid Services data review. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Impact of aspirin resistance on outcomes among patients following coronary artery bypass grafting: exploratory analysis from randomized controlled trial (NCT01159639).

    PubMed

    Petricevic, Mate; Kopjar, Tomislav; Gasparovic, Hrvoje; Milicic, Davor; Svetina, Lucija; Zdilar, Boris; Boban, Marko; Mihaljevic, Martina Zrno; Biocina, Bojan

    2015-05-01

    Individual variability in the response to aspirin, has been established by various platelet function assays, however, the clinical relevance of aspirin resistance (AR) in patients undergoing coronary artery bypass grafting (CABG) has to be evaluated. Our working group conducted a randomized controlled trial (NCT01159639) with the aim to assess impact of dual antiplatelet therapy (APT) on outcomes among patients with AR following CABG. Patients that were aspirin resistant on fourth postoperative day (POD 4) were randomly assigned to receive either dual APT with clopidogrel (75 mg) plus aspirin (300 mg)-intervention arm or monotherapy with aspirin (300 mg)-control arm. This exploratory analysis compares clinical outcomes between aspirin resistant patients allocated to control arm and patients that have had adequate platelet inhibitory response to aspirin at POD 4. Both groups were treated with 300 mg of aspirin per day following surgery. We sought to evaluate the impact of early postoperative AR on outcomes among patients following CABG. Exploratory analysis included a total number of 325 patients. Of those, 215 patients with adequate response to aspirin and 110 patients with AR allocated to aspirin monotherapy following randomization protocol. The primary efficacy end point (MACCEs-major adverse cardiac and cardiovascular events) occurred in 10 and 6 % of patients with AR and with adequate aspirin response, respectively (p = 0.27). Non-significant differences were observed in bleeding events occurrence. Subgroup analysis of the primary end point revealed that aspirin resistant patients with BMI > 30 kg/m(2) tend to have a higher occurrence of MACCEs 18 versus 5 % (relative risk 0.44 [95 % CI 0.16-1.16]; p = 0.05). This exploratory analysis did not reveal significant impact of aspirin resistance on outcomes among patients undergoing CABG. Further, sufficiently powered studies are needed in order to evaluate clinical relevance of AR in patients undergoing CABG.

  18. Kidney function endpoints in kidney transplant trials: a struggle for power.

    PubMed

    Ibrahim, A; Garg, A X; Knoll, G A; Akbari, A; White, C A

    2013-03-01

    Kidney function endpoints are commonly used in randomized controlled trials (RCTs) in kidney transplantation (KTx). We conducted this study to estimate the proportion of ongoing RCTs with kidney function endpoints in KTx where the proposed sample size is large enough to detect meaningful differences in glomerular filtration rate (GFR) with adequate statistical power. RCTs were retrieved using the key word "kidney transplantation" from the National Institute of Health online clinical trial registry. Included trials had at least one measure of kidney function tracked for at least 1 month after transplant. We determined the proportion of two-arm parallel trials that had sufficient sample sizes to detect a minimum 5, 7.5 and 10 mL/min difference in GFR between arms. Fifty RCTs met inclusion criteria. Only 7% of the trials were above a sample size of 562, the number needed to detect a minimum 5 mL/min difference between the groups should one exist (assumptions: α = 0.05; power = 80%, 10% loss to follow-up, common standard deviation of 20 mL/min). The result increased modestly to 36% of trials when a minimum 10 mL/min difference was considered. Only a minority of ongoing trials have adequate statistical power to detect between-group differences in kidney function using conventional sample size estimating parameters. For this reason, some potentially effective interventions which ultimately could benefit patients may be abandoned from future assessment. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

  19. Transabdominal amnioinfusion for preterm premature rupture of membranes: a systematic review and metaanalysis of randomized and observational studies.

    PubMed

    Porat, Shay; Amsalem, Hagai; Shah, Prakesh S; Murphy, Kellie E

    2012-11-01

    The purpose of this study was to review systematically the efficacy of transabdominal amnioinfusion (TA) in early preterm premature rupture of membranes (PPROM). We conducted a literature search of EMBASE, MEDLINE, and ClinicalTrials.gov databases and identified studies in which TA was used in cases of proven PPROM and oligohydramnios. Risk of bias was assessed for observational studies and randomized controlled trials. Primary outcomes were latency period and perinatal mortality rates. Four observational studies (n = 147) and 3 randomized controlled trials (n = 165) were eligible. Pooled latency period was 14.4 (range, 8.2-20.6) and 11.41 (range -3.4 to 26.2) days longer in the TA group in the observational and the randomized controlled trials, respectively. Perinatal mortality rates were reduced among the treatment groups in both the observational studies (odds ratio, 0.12; 95% confidence interval, 0.02-0.61) and the randomized controlled trials (odds ratio, 0.33; 95% confidence interval, 0.10-1.12). Serial TA for early PPROM may improve early PPROM-associated morbidity and mortality rates. Additional adequately powered randomized control trials are needed. Copyright © 2012 Mosby, Inc. All rights reserved.

  20. Methodological reporting quality of randomized controlled trials: A survey of seven core journals of orthopaedics from Mainland China over 5 years following the CONSORT statement.

    PubMed

    Zhang, J; Chen, X; Zhu, Q; Cui, J; Cao, L; Su, J

    2016-11-01

    In recent years, the number of randomized controlled trials (RCTs) in the field of orthopaedics is increasing in Mainland China. However, randomized controlled trials (RCTs) are inclined to bias if they lack methodological quality. Therefore, we performed a survey of RCT to assess: (1) What about the quality of RCTs in the field of orthopedics in Mainland China? (2) Whether there is difference between the core journals of the Chinese department of orthopedics and Orthopaedics Traumatology Surgery & Research (OTSR). This research aimed to evaluate the methodological reporting quality according to the CONSORT statement of randomized controlled trials (RCTs) in seven key orthopaedic journals published in Mainland China over 5 years from 2010 to 2014. All of the articles were hand researched on Chongqing VIP database between 2010 and 2014. Studies were considered eligible if the words "random", "randomly", "randomization", "randomized" were employed to describe the allocation way. Trials including animals, cadavers, trials published as abstracts and case report, trials dealing with subgroups analysis, or trials without the outcomes were excluded. In addition, eight articles selected from Orthopaedics Traumatology Surgery & Research (OTSR) between 2010 and 2014 were included in this study for comparison. The identified RCTs are analyzed using a modified version of the Consolidated Standards of Reporting Trials (CONSORT), including the sample size calculation, allocation sequence generation, allocation concealment, blinding and handling of dropouts. A total of 222 RCTs were identified in seven core orthopaedic journals. No trials reported adequate sample size calculation, 74 (33.4%) reported adequate allocation generation, 8 (3.7%) trials reported adequate allocation concealment, 18 (8.1%) trials reported adequate blinding and 16 (7.2%) trials reported handling of dropouts. In OTSR, 1 (12.5%) trial reported adequate sample size calculation, 4 (50.0%) reported adequate allocation generation, 1 (12.5%) trials reported adequate allocation concealment, 2 (25.0%) trials reported adequate blinding and 5 (62.5%) trials reported handling of dropouts. There were statistical differences as for sample size calculation and handling of dropouts between papers from Mainland China and OTSR (P<0.05). The findings of this study show that the methodological reporting quality of RCTs in seven core orthopaedic journals from the Mainland China is far from satisfaction and it needs to further improve to keep up with the standards of the CONSORT statement. Level III case control. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Explanation of random experiment sheduling and its application to space station analysis

    NASA Technical Reports Server (NTRS)

    Moore, J. E.

    1970-01-01

    The capability of the McDonnell-Douglas Phase B space station concept to complete the Blue Book Experiment program is analyzed and the Random experiment program with Resource Impact (REPRI) which was used to generate the data is described. The results indicate that station manpower and electrical power are the two resources which will constrain the amount of the Blue Book program that the station can complete. The station experiment program and its resource requirements are sensitive to levels of manpower and electrical power 13.5 men and 11 kilowatts. Continuous artificial gravity experiments have much less impact on the experiment program than experiments using separate artificial gravity periods. Station storage volume presently allocated for the FPE's and their supplies (1600 cu ft) is more than adequate. The REPRI program uses the Monte Carlo technique to generate a set of feasible experiment schedules for a space station. The schedules are statistically analyzed to determine the impact of the station experiment program resource requirements on the station concept. Also, the sensitivity of the station concept to one or more resources is assessed.

  2. Chelation therapy to treat atherosclerosis, particularly in diabetes: is it time to reconsider?

    PubMed

    Lamas, Gervasio A; Ergui, Ian

    2016-08-01

    Case reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes. The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. We discuss results and future research. Expert commentary: Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years, with a 41% relative reduction in risk of a cardiac event (p = 0.0002). These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. We are seeking participating sites for TACT2.

  3. Escitalopram treatment of depression in human immunodeficiency virus/acquired immunodeficiency syndrome: a randomized, double-blind, placebo-controlled study.

    PubMed

    Hoare, Jacqueline; Carey, Paul; Joska, John A; Carrara, Henri; Sorsdahl, Katherine; Stein, Dan J

    2014-02-01

    Depression can be a chronic and impairing illness in people with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome. Large randomized studies of newer selective serotonin reuptake inhibitors such as escitalopram in the treatment of depression in HIV, examining comparative treatment efficacy and safety, have yet to be done in HIV-positive patients. This was a fixed-dose, placebo-controlled, randomized, double-blind study to investigate the efficacy of escitalopram in HIV-seropositive subjects with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, major depressive disorder. One hundred two participants were randomly assigned to either 10 mg of escitalopram or placebo for 6 weeks. An analysis of covariance of the completers found that there was no advantage for escitalopram over placebo on the Montgomery-Asberg Depression Rating Scale (p = 0.93). Sixty-two percent responded to escitalopram and 59% responded to placebo on the Clinical Global Impression Scale. Given the relatively high placebo response, future trials in this area need to be selective in participant recruitment and to be adequately powered.

  4. Assessment and Implication of Prognostic Imbalance in Randomized Controlled Trials with a Binary Outcome – A Simulation Study

    PubMed Central

    Chu, Rong; Walter, Stephen D.; Guyatt, Gordon; Devereaux, P. J.; Walsh, Michael; Thorlund, Kristian; Thabane, Lehana

    2012-01-01

    Background Chance imbalance in baseline prognosis of a randomized controlled trial can lead to over or underestimation of treatment effects, particularly in trials with small sample sizes. Our study aimed to (1) evaluate the probability of imbalance in a binary prognostic factor (PF) between two treatment arms, (2) investigate the impact of prognostic imbalance on the estimation of a treatment effect, and (3) examine the effect of sample size (n) in relation to the first two objectives. Methods We simulated data from parallel-group trials evaluating a binary outcome by varying the risk of the outcome, effect of the treatment, power and prevalence of the PF, and n. Logistic regression models with and without adjustment for the PF were compared in terms of bias, standard error, coverage of confidence interval and statistical power. Results For a PF with a prevalence of 0.5, the probability of a difference in the frequency of the PF≥5% reaches 0.42 with 125/arm. Ignoring a strong PF (relative risk = 5) leads to underestimating the strength of a moderate treatment effect, and the underestimate is independent of n when n is >50/arm. Adjusting for such PF increases statistical power. If the PF is weak (RR = 2), adjustment makes little difference in statistical inference. Conditional on a 5% imbalance of a powerful PF, adjustment reduces the likelihood of large bias. If an absolute measure of imbalance ≥5% is deemed important, including 1000 patients/arm provides sufficient protection against such an imbalance. Two thousand patients/arm may provide an adequate control against large random deviations in treatment effect estimation in the presence of a powerful PF. Conclusions The probability of prognostic imbalance in small trials can be substantial. Covariate adjustment improves estimation accuracy and statistical power, and hence should be performed when strong PFs are observed. PMID:22629322

  5. Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? A systematic review.

    PubMed

    Donnelly, Joseph E; Herrmann, Stephen D; Lambourne, Kate; Szabo, Amanda N; Honas, Jeffery J; Washburn, Richard A

    2014-01-01

    The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. TO ADDRESS THE QUESTION: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? PubMed and Embase were searched (January 1990-January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18-64 years). Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake.

  6. Clinical trial design for orthodontists.

    PubMed

    Pandis, Nikolaos; Cobourne, Martyn T

    2013-06-01

    High-quality research should form the basis of all clinical practice. Randomized controlled trials currently provide the gold standard for investigating the effectiveness of treatment interventions and these are increasingly being used in orthodontics. Here we discuss the reasons why this form of investigation provides the most useful evidence for assessing treatment outcome. The methods available to achieve true randomization, a fundamental component in the design of these trials, are also discussed. In addition, we focus on how to minimize bias in clinical research, not only during the design and management of a trial, but also when disseminating results. We focus on the importance of using control groups correctly and describe methods that are available to adequately power a trial. Finally, we emphasise the importance of accurate and transparent reporting, which facilitates correct communication and assessment of the evidence.

  7. Warfarin versus aspirin in patients with reduced cardiac ejection fraction (WARCEF): rationale, objectives, and design.

    PubMed

    Pullicino, Patrick; Thompson, John L P; Barton, Bruce; Levin, Bruce; Graham, Susan; Freudenberger, Ronald S

    2006-02-01

    Warfarin is widely prescribed for patients with heart failure without level 1 evidence, and an adequately powered randomized study is needed. The Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction study is a National Institutes of Health-funded, randomized, double-blind clinical trial with a target enrollment of 2860 patients. It is designed to test with 90% power the 2-sided primary null hypothesis of no difference between warfarin (International Normalized Ratio 2.5-3) and aspirin (325 mg) in 3- to 5-year event-free survival for the composite endpoint of death, or stroke (ischemic or hemorrhagic) among patients with cardiac ejection fraction < or =35% who do not have atrial fibrillation or mechanical prosthetic heart valves. Secondary analyses will compare warfarin and aspirin for reduction of all-cause mortality, ischemic stroke, and myocardial infarction (MI), balanced against the risk of intracerebral hemorrhage, among women and African Americans; and compare warfarin and aspirin for prevention of stroke alone. Randomization is stratified by site, New York Heart Association (NYHA) heart class (I vs II-IV), and stroke or transient ischemic attack (TIA) within 1 year before randomization versus no stroke or TIA in that period. NYHA class I patients will not exceed 20%, and the study has a target of 20% (or more) patients with stroke or TIA within 12 months. Randomized patients receive active warfarin plus placebo or active aspirin plus placebo, double-blind. The results should help guide the selection of optimum antithrombotic therapy for patients with left ventricular dysfunction.

  8. 46 CFR 199.110 - Survival craft muster and embarkation arrangements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be adequately illuminated by lighting with power supplied from the vessel's emergency source of electrical power. (d) Each alleyway, stairway, and exit giving access to a muster and embarkation station must be adequately illuminated by lighting that is capable of having its power supplied by the vessel's...

  9. 46 CFR 199.110 - Survival craft muster and embarkation arrangements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... be adequately illuminated by lighting with power supplied from the vessel's emergency source of electrical power. (d) Each alleyway, stairway, and exit giving access to a muster and embarkation station must be adequately illuminated by lighting that is capable of having its power supplied by the vessel's...

  10. Polyethylene glycol-induced motor recovery after total spinal transection in rats.

    PubMed

    Ren, Shuai; Liu, Ze-Han; Wu, Qiong; Fu, Kuang; Wu, Jun; Hou, Li-Ting; Li, Ming; Zhao, Xin; Miao, Qing; Zhao, Yun-Long; Wang, Sheng-Yu; Xue, Yan; Xue, Zhen; Guo, Ya-Shan; Canavero, Sergio; Ren, Xiao-Ping

    2017-08-01

    Despite more than a century of research, spinal paralysis remains untreatable via biological means. A new understanding of spinal cord physiology and the introduction of membrane fusogens have provided new hope that a biological cure may soon become available. However, proof is needed from adequately powered animal studies. Two groups of rats (n=9, study group, n=6 controls) were submitted to complete transection of the dorsal cord at T10. The animals were randomized to receive either saline or polyethylene glycol (PEG) in situ. After 4 weeks, the treated group had recovered ambulation vs none in the control group (BBB scores; P=.0145). One control died. All animals were studied with somatosensory-evoked potentials (SSEP) and diffusion tensor imaging (DTI). SSEP recovered postoperatively only in PEG-treated rats. At study end, DTI showed disappearance of the transection gap in the treated animals vs an enduring gap in controls (fractional anisotropy/FA at level: P=.0008). We show for the first time in an adequately powered study that the paralysis attendant to a complete transection of the spinal cord can be reversed. This opens the path to a severance-reapposition cure of spinal paralysis, in which the injured segment is excised and the two stumps approximated after vertebrectomy/diskectomies. © 2017 John Wiley & Sons Ltd.

  11. Optimized design and analysis of preclinical intervention studies in vivo

    PubMed Central

    Laajala, Teemu D.; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero

    2016-01-01

    Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions. PMID:27480578

  12. Optimized design and analysis of preclinical intervention studies in vivo.

    PubMed

    Laajala, Teemu D; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero

    2016-08-02

    Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions.

  13. Neuropharmacology of Poststroke Motor and Speech Recovery.

    PubMed

    Keser, Zafer; Francisco, Gerard E

    2015-11-01

    Almost 7 million adult Americans have had a stroke. There is a growing need for more effective treatment options as add-ons to conventional therapies. This article summarizes the published literature for pharmacologic agents used for the enhancement of motor and speech recovery after stroke. Amphetamine, levodopa, selective serotonin reuptake inhibitors, and piracetam were the most commonly used drugs. Pharmacologic augmentation of stroke motor and speech recovery seems promising but systematic, adequately powered, randomized, and double-blind clinical trials are needed. At this point, the use of these pharmacologic agents is not supported by class I evidence. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Sickle cell disease and venous thromboembolism in pregnancy and the puerperium.

    PubMed

    Noubouossie, Denis; Key, Nigel S

    2015-02-01

    Recent data strongly suggest an increased risk of venous thromboembolism in subjects with sickle cell disease and to a lesser extent, sickle cell trait. However, most studies have been retrospective, case-control or cross-sectional based on data obtained from administrative databases. More data from adequately powered prospective studies that include matched controls are needed to definitely establish the link between venous thromboembolism during pregnancy and sickle hemoglobin disorders. Similarly, there remains a need for properly designed randomized control trials to establish the safety of various hormonal contraceptive methods in women with sickle cell disorders. © 2015 Elsevier Ltd. All rights reserved.

  15. Quality of radiotherapy reporting in randomized controlled trials of prostate cancer.

    PubMed

    Soon, Yu Yang; Chen, Desiree; Tan, Teng Hwee; Tey, Jeremy

    2018-06-07

    Good radiotherapy reporting in clinical trials of prostate radiotherapy is important because it will allow accurate reproducibility of radiotherapy treatment and minimize treatment variations that can affect patient outcomes. The aim of our study is to assess the quality of prostate radiotherapy (RT) treatment reporting in randomized controlled trials in prostate cancer. We searched MEDLINE for randomized trials of prostate cancer, published from 1996 to 2016 and included prostate RT as one of the intervention arms. We assessed if the investigators reported the ten criteria adequately in the trial reports: RT dose prescription method; RT dose-planning procedures; organs at risk (OAR) dose constraints; target volume definition, simulation procedures; treatment verification procedures; total RT dose; fractionation schedule; conduct of quality assurance (QA) as well as presence or absence of deviations in RT treatment planning and delivery. We performed multivariate logistic regression to determine the factors that may influence the quality of reporting. We found 59 eligible trials. There was significant variability in the quality of reporting. Target volume definition, total RT dose and fractionation schedule were reported adequately in 97% of included trials. OAR constraints, simulation procedures and presence or absence of deviations in RT treatment planning and delivery were reported adequately in 30% of included trials. Twenty-four trials (40%) reported seven criteria or more adequately. Multivariable logistic analysis showed that trials that published their quality assurance results and cooperative group trials were more likely to have adequate quality in reporting in at least seven criteria. There is significant variability in the quality of reporting on prostate radiotherapy treatment in randomized trials of prostate cancer. We need to have consensus guidelines to standardize the reporting of radiotherapy treatment in randomized trials.

  16. [An investigation of the statistical power of the effect size in randomized controlled trials for the treatment of patients with type 2 diabetes mellitus using Chinese medicine].

    PubMed

    Ma, Li-Xin; Liu, Jian-Ping

    2012-01-01

    To investigate whether the power of the effect size was based on adequate sample size in randomized controlled trials (RCTs) for the treatment of patients with type 2 diabetes mellitus (T2DM) using Chinese medicine. China Knowledge Resource Integrated Database (CNKI), VIP Database for Chinese Technical Periodicals (VIP), Chinese Biomedical Database (CBM), and Wangfang Data were systematically recruited using terms like "Xiaoke" or diabetes, Chinese herbal medicine, patent medicine, traditional Chinese medicine, randomized, controlled, blinded, and placebo-controlled. Limitation was set on the intervention course > or = 3 months in order to identify the information of outcome assessement and the sample size. Data collection forms were made according to the checking lists found in the CONSORT statement. Independent double data extractions were performed on all included trials. The statistical power of the effects size for each RCT study was assessed using sample size calculation equations. (1) A total of 207 RCTs were included, including 111 superiority trials and 96 non-inferiority trials. (2) Among the 111 superiority trials, fasting plasma glucose (FPG) and glycosylated hemoglobin HbA1c (HbA1c) outcome measure were reported in 9% and 12% of the RCTs respectively with the sample size > 150 in each trial. For the outcome of HbA1c, only 10% of the RCTs had more than 80% power. For FPG, 23% of the RCTs had more than 80% power. (3) In the 96 non-inferiority trials, the outcomes FPG and HbA1c were reported as 31% and 36% respectively. These RCTs had a samples size > 150. For HbA1c only 36% of the RCTs had more than 80% power. For FPG, only 27% of the studies had more than 80% power. The sample size for statistical analysis was distressingly low and most RCTs did not achieve 80% power. In order to obtain a sufficient statistic power, it is recommended that clinical trials should establish clear research objective and hypothesis first, and choose scientific and evidence-based study design and outcome measurements. At the same time, calculate required sample size to ensure a precise research conclusion.

  17. Methodological reporting of randomized clinical trials in respiratory research in 2010.

    PubMed

    Lu, Yi; Yao, Qiuju; Gu, Jie; Shen, Ce

    2013-09-01

    Although randomized controlled trials (RCTs) are considered the highest level of evidence, they are also subject to bias, due to a lack of adequately reported randomization, and therefore the reporting should be as explicit as possible for readers to determine the significance of the contents. We evaluated the methodological quality of RCTs in respiratory research in high ranking clinical journals, published in 2010. We assessed the methodological quality, including generation of the allocation sequence, allocation concealment, double-blinding, sample-size calculation, intention-to-treat analysis, flow diagrams, number of medical centers involved, diseases, funding sources, types of interventions, trial registration, number of times the papers have been cited, journal impact factor, journal type, and journal endorsement of the CONSORT (Consolidated Standards of Reporting Trials) rules, in RCTs published in 12 top ranking clinical respiratory journals and 5 top ranking general medical journals. We included 176 trials, of which 93 (53%) reported adequate generation of the allocation sequence, 66 (38%) reported adequate allocation concealment, 79 (45%) were double-blind, 123 (70%) reported adequate sample-size calculation, 88 (50%) reported intention-to-treat analysis, and 122 (69%) included a flow diagram. Multivariate logistic regression analysis revealed that journal impact factor ≥ 5 was the only variable that significantly influenced adequate allocation sequence generation. Trial registration and journal impact factor ≥ 5 significantly influenced adequate allocation concealment. Medical interventions, trial registration, and journal endorsement of the CONSORT statement influenced adequate double-blinding. Publication in one of the general medical journal influenced adequate sample-size calculation. The methodological quality of RCTs in respiratory research needs improvement. Stricter enforcement of the CONSORT statement should enhance the quality of RCTs.

  18. Optimal sample sizes for the design of reliability studies: power consideration.

    PubMed

    Shieh, Gwowen

    2014-09-01

    Intraclass correlation coefficients are used extensively to measure the reliability or degree of resemblance among group members in multilevel research. This study concerns the problem of the necessary sample size to ensure adequate statistical power for hypothesis tests concerning the intraclass correlation coefficient in the one-way random-effects model. In view of the incomplete and problematic numerical results in the literature, the approximate sample size formula constructed from Fisher's transformation is reevaluated and compared with an exact approach across a wide range of model configurations. These comprehensive examinations showed that the Fisher transformation method is appropriate only under limited circumstances, and therefore it is not recommended as a general method in practice. For advance design planning of reliability studies, the exact sample size procedures are fully described and illustrated for various allocation and cost schemes. Corresponding computer programs are also developed to implement the suggested algorithms.

  19. Can pregnant diabetics be treated with glyburide?

    PubMed

    Melamed, Nir; Yogev, Yariv

    2009-11-01

    Until the last decade, oral hypoglycemic agents have not been recommended in pregnancy owing to fear of their potential adverse fetal effects, including teratogenicity and neonatal hypoglycemia. However, the evidence in support of these recommendations is weak and is principally based on case series involving the use of first-generation sulfonylureas. Studies using a single-cotyledon placental model have found glyburide to only minimally cross the placenta, an observation that paved the way for a landmark randomized clinical trial that found glyburide to be as safe and effective as insulin in the management of gestational diabetes mellitus. Still, contradicting results regarding its trans-placental transfer, lack of adequate data regarding its safety during the first trimester and reports of increased neonatal morbidity raise concerns regarding the universal application of glyburide as an alternative to insulin therapy in diabetic pregnant women. Thus, there is a need for large, randomized, controlled trials with adequate power to evaluate the possibility of increased neonatal metabolic complications as well as the long-term outcome of infants born to mothers treated with glyburide and insulin. Unless future studies refute current data regarding the efficacy and safety of glyburide, we believe that, owing to its ease of administration, convenience and low cost, glyburide will become the first line of medical treatment in patients with gestational diabetes mellitus within the next few years.

  20. Does Increased Exercise or Physical Activity Alter Ad-Libitum Daily Energy Intake or Macronutrient Composition in Healthy Adults? A Systematic Review

    PubMed Central

    Donnelly, Joseph E.; Herrmann, Stephen D.; Lambourne, Kate; Szabo, Amanda N.; Honas, Jeffery J.; Washburn, Richard A.

    2014-01-01

    Background The magnitude of the negative energy balance induced by exercise may be reduced due to compensatory increases in energy intake. Objective To address the question: Does increased exercise or physical activity alter ad-libitum daily energy intake or macronutrient composition in healthy adults? Data Sources PubMed and Embase were searched (January 1990–January 2013) for studies that presented data on energy and/or macronutrient intake by level of exercise, physical activity or change in response to exercise. Ninety-nine articles (103 studies) were included. Study Eligibility Criteria Primary source articles published in English in peer-reviewed journals. Articles that presented data on energy and/or macronutrient intake by level of exercise or physical activity or changes in energy or macronutrient intake in response to acute exercise or exercise training in healthy (non-athlete) adults (mean age 18–64 years). Study Appraisal and Synthesis Methods Articles were grouped by study design: cross-sectional, acute/short term, non-randomized, and randomized trials. Considerable heterogeneity existed within study groups for several important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and presented by study design. Results No effect of physical activity, exercise or exercise training on energy intake was shown in 59% of cross-sectional studies (n = 17), 69% of acute (n = 40), 50% of short-term (n = 10), 92% of non-randomized (n = 12) and 75% of randomized trials (n = 24). Ninety-four percent of acute, 57% of short-term, 100% of non-randomized and 74% of randomized trials found no effect of exercise on macronutrient intake. Forty-six percent of cross-sectional trials found lower fat intake with increased physical activity. Limitations The literature is limited by the lack of adequately powered trials of sufficient duration, which have prescribed and measured exercise energy expenditure, or employed adequate assessment methods for energy and macronutrient intake. Conclusions We found no consistent evidence that increased physical activity or exercise effects energy or macronutrient intake. PMID:24454704

  1. Ultrasound therapy transducers with space-filling non-periodic arrays.

    PubMed

    Raju, Balasundar I; Hall, Christopher S; Seip, Ralf

    2011-05-01

    Ultrasound transducers designed for therapeutic purposes such as tissue ablation, histotripsy, or drug delivery require large apertures for adequate spatial localization while providing sufficient power and steerability without the presence of secondary grating lobes. In addition, it is highly preferred to minimize the total number of channels and to maintain simplicity in electrical matching network design. To this end, we propose array designs that are both space-filling and non-periodic in the placement of the elements. Such array designs can be generated using the mathematical concept of non-periodic or aperiodic tiling (tessellation) and can lead to reduced grating lobes while maintaining full surface area coverage to deliver maximum power. For illustration, we designed two 2-D space-filling therapeutic arrays with 128 elements arranged on a spherical shell. One was based on the two-shape Penrose rhombus tiling, and the other was based on a single rectangular shape arranged non-periodically. The steerability performance of these arrays was studied using acoustic field simulations. For comparison, we also studied two other arrays, one with circular elements distributed randomly, and the other a periodic array with square elements. Results showed that the two space-filling non-periodic arrays were able to steer to treat a volume of 16 x 16 x 20 mm while ensuring that the grating lobes were under -10 dB compared with the main lobe. The rectangular non-periodic array was able to generate two and half times higher power than the random circles array. The rectangular array was then fabricated by patterning the array using laser scribing methods and its steerability performance was validated using hydrophone measurements. This work demonstrates that the concept of space-filling aperiodic/non-periodic tiling can be used to generate therapy arrays that are able to provide higher power for the same total transducer area compared with random arrays while maintaining acceptable grating lobe levels.

  2. Beneficial and adverse effects of testosterone on the cardiovascular system in men.

    PubMed

    Ruige, Johannes B; Ouwens, D Margriet; Kaufman, Jean-Marc

    2013-11-01

    The widespread use of T therapy, particularly in aging males, necessitates knowledge of the relationship between T and the cardiovascular system. The review is based on a 1970 to 2013 PubMed search with terms related to androgens in combination with cardiovascular disease, including T, dihydrotestosterone, trial, mortality, cardiovascular disease, myocardial infarction, blood pressure, endothelial function, dyslipidemia, thrombosis, ventricular function, and arrhythmia. Original articles, systematic reviews and meta-analyses, and relevant citations were screened. Low T has been linked to increased blood pressure, dyslipidemia, atherosclerosis, arrhythmia, thrombosis, endothelial dysfunction, as well as to impaired left ventricular function. On the one hand, a modest association is suggested between low endogenous T and incident cardiovascular disease or cardiovascular mortality, implying unrecognized beneficial T effects, residual confounding, or a relationship with health status. On the other hand, treatments with T to restore "normal concentrations" have so far not been proven to be beneficial with respect to cardiovascular disease; neither have they definitely shown specific adverse cardiovascular effects. The cardiovascular risk-benefit profile of T therapy remains largely evasive in view of a lack of well-designed and adequately powered randomized clinical trials. The important knowledge gap as to the exact relationship between T and cardiovascular disease would support a cautious, restrained approach to T therapy in aging men, pending clarification of benefits and risks by adequately powered clinical trials of sufficient duration.

  3. Optimal Order of Successive Office Hysteroscopy and Endometrial Biopsy for the Evaluation of Abnormal Uterine Bleeding: A Randomized Controlled Trial.

    PubMed

    Sarkar, Papri; Mikhail, Emad; Schickler, Robyn; Plosker, Shayne; Imudia, Anthony N

    2017-09-01

    To estimate the optimal order of office hysteroscopy and endometrial biopsy when performed successively for evaluation of abnormal uterine bleeding. Patients undergoing successive office hysteroscopy and endometrial biopsy were included in a single-blind, prospective, randomized trial. The primary outcome was to evaluate the effect of order of procedures on patients' pain score. Prespecified secondary outcomes include procedure duration, hysteroscopic visualization of the uterine cavity, endometrial sample adequacy, and number of attempts at biopsy. Pain scores were assessed using a visual analog scale from 0 to 10 and endometrial sample adequacy was determined from the histopathology report. Hysteroscopy images were recorded. Sample size of 34 per group (n=68) was determined to be adequate to detect a difference of 20% in visual analog scale score between hysteroscopy first (group A) and biopsy first (group B) at α of 0.05 and 80% power. Between October 2015 and January 2017, 78 women were randomized to group A (n=40) and group B (n=38). There was no difference in global pain perception [7 (0-10) vs 7 (0-10); P=.57, 95% CI 5.8-7.1]. Procedure duration [3 (1-9) vs 3 (2-10), P=.32, 95% CI 3.3-4.1] and endometrial sample adequacy (78.9% vs 75.7%, P=.74) were similar in both groups. Group A patients had better endometrial visualization (P<.001) than group B based on the hysteroscopic images: excellent (50% vs 7.9%), good (20% vs 34.2%), and fair (22.5% vs 44.7%); group B participants required fewer endometrial biopsy attempts at obtaining adequate tissue sample (two vs one; P<.001, 1.6-1.9). Patients having successive office hysteroscopy and endometrial biopsy for evaluation of abnormal uterine bleeding, the global pain perception, and time required are independent of the order in which procedures are performed. Performing hysteroscopy first ensures better image, whereas biopsy first yields adequate tissue sample with fewer attempts. ClinicalTrials.gov, NCT02472184.

  4. Continued midazolam versus diphenhydramine in difficult-to-sedate patients: a randomized double-blind trial.

    PubMed

    Sachar, Hamita; Pichetshote, Nipaporn; Nandigam, Kavitha; Vaidya, Keta; Laine, Loren

    2018-05-01

    Current guidelines recommend diphenhydramine in patients undergoing endoscopy who are not adequately sedated with a benzodiazepine and opioid combination. Because this practice has not been adequately assessed, we performed a randomized, double-blind trial comparing diphenhydramine with continued midazolam in such patients. Patients undergoing elective colonoscopy with moderate sedation were eligible. Sedation was measured with the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score with adequate sedation defined as 3 on a 0- to 5-point scale. Patients not adequately sedated with midazolam 5 mg and fentanyl 100 μg were randomly assigned to diphenhydramine 25 mg versus continued midazolam 1.5 mg. Adequacy of sedation was assessed 3 minutes after each study medication dose. If MOAA/S was 4 to 5, study medication was repeated, to a maximum of 3 doses. The primary endpoint was adequate sedation. The planned enrollment of 200 patients (100 in each study group) was attained. Adequate sedation was achieved less often with diphenhydramine than midazolam (27% vs 65%, difference = -38%; 95% CI, -50% to -24%; P < .0001). After study medications were completed, more patients required additional medication for sedation or analgesia with diphenhydramine versus midazolam (84% vs 68%, P = .008), whereas the time to discharge from the recovery unit was similar (134 vs 129 minutes). Treatment effect was consistent across subgroups including age ≤55, substance abuse, benzodiazepine use, opioid use, and psychiatric medication use. Endoscopists performing moderate sedation should continue midazolam rather than switching to diphenhydramine in patients who do not achieve adequate sedation with usual doses of midazolam and an opioid. (Clinical trial registration number: NCT01769586.). Published by Elsevier Inc.

  5. On the Choice of Adequate Randomization Ranges for Limiting the Use of Unwanted Cues in Same-Different, Dual-Pair, and Oddity Tasks

    PubMed Central

    Dai, Huanping; Micheyl, Christophe

    2010-01-01

    A major concern when designing a psychophysical experiment is that participants may use another stimulus feature (“cue”) than that intended by the experimenter. One way to avoid this involves applying random variations to the corresponding feature across stimulus presentations, to make the “unwanted” cue unreliable. An important question facing experimenters who use this randomization (“roving”) technique is: How large should the randomization range be to ensure that participants cannot achieve a certain proportion correct (PC) by using the unwanted cue, while at the same time avoiding unnecessary interference of the randomization with task performance? Previous publications have provided formulas for the selection of adequate randomization ranges in yes-no and multiple-alternative, forced-choice tasks. In this article, we provide figures and tables, which can be used to select randomization ranges that are better suited to experiments involving a same-different, dual-pair, or oddity task. PMID:20139466

  6. Randomized comparison of power Doppler ultrasonography-guided core-needle biopsy with open surgical biopsy for the characterization of lymphadenopathies in patients with suspected lymphoma.

    PubMed

    Pugliese, Novella; Di Perna, M; Cozzolino, I; Ciancia, G; Pettinato, G; Zeppa, P; Varone, V; Masone, S; Cerchione, C; Della Pepa, R; Simeone, L; Giordano, C; Martinelli, V; Salvatore, C; Pane, F; Picardi, M

    2017-04-01

    The sensitivity of lymph node core-needle biopsy under imaging guidance requires validation. We employed power Doppler ultrasonography (PDUS) to select the lymph node most suspected of malignancy and to histologically characterize it through the use of large cutting needle. Institutional review board approval and informed consent were obtained for this randomized clinical trial. In a single center between 1 January 2009 and 31 December 2015, patients with lymph node enlargement suspected for lymphoma were randomly assigned (1:1) to biopsy with either standard surgery or PDUS-guided 16-gauge modified Menghini needle. The primary endpoint was the superiority of sensitivity for the diagnosis of malignancy for core-needle cutting biopsy (CNCB). Secondary endpoints were times to biopsy, complications, and costs. A total of 376 patients were randomized into the two arms and received allocated biopsy. However, four patients undergoing CNCB were excluded for inadequate samples; thus, 372 patients were analyzed. Sensitivity for the detection of malignancy was significantly better for PDUS-guided CNCB [98.8%; 95% confidence interval (CI), 95.9-99.9] than standard biopsy (88.7%; 95% CI, 82.9-93; P < 0.001). For all secondary endpoints, the comparison was significantly disadvantageous for conventional approach. In particular, estimated cost per biopsy performed with standard surgery was 24-fold higher compared with that performed with CNCB. The presence of satellite enlarged reactive and/or necrotic lymph nodes may impair the success of an open surgical biopsy (OSB). PDUS and CNCB with adequate gauge are diagnostic tools that enable effective, safe, fast, and low-cost routine biopsy for patients with suspected lymphoma, avoiding psychological and physical pain of an unnecessary surgical intervention.

  7. Effects of active/passive interventions on pain, anxiety, and quality of life in women with fibromyalgia: Randomized controlled pilot trial.

    PubMed

    Ekici, Gamze; Unal, Edibe; Akbayrak, Turkan; Vardar-Yagli, Naciye; Yakut, Yavuz; Karabulut, Erdem

    2017-01-01

    The authors of this study compared the effects of pilates exercises and connective tissue massage (CTM) on pain intensity; pain-pressure threshold; and tolerance, anxiety, progress, and health-related quality of life in females with fibromyalgia. It was a pilot, assessor masked, randomized controlled trial conducted between January and August of 2013. Twenty-one women with fibromyalgia were randomly assigned to the pilates exercise program (six of whom did not complete the program), and 22 were randomly assigned to CTM (one of whom did not complete this program). Each group received the assigned intervention three times per week during a 4-week period. The Visual Analogue Scale, algometry, State-Trait Anxiety Inventory, Fibromyalgia Impact Questionnaire, and Nottingham Health Profile were used at baseline and at the end of treatments. Significant improvements were found in both groups for all parameters. However, the scores for pain-pressure threshold were significantly elevated and the symptoms of anxiety were significantly diminished in the exercise group compared to the massage group. Thus, exercise and massage might be used to provide improvements in women with fibromyalgia. The exercise group showed more advantages than the massage group and thus might be preferred for patients with fibromyalgia. However, an adequately powered trial is required to determine this with certainty.

  8. [Patient's individuality and application of guidelines in surgery].

    PubMed

    Schulte, Michael

    2005-01-01

    Individual treatment decisions can become considerably conflictual in view of the co-existence of medical professional guidelines, recommendations based on evidence-based medicine (EBM), and juridical and economical directions. Medical guidelines are not subject to an external review process; also, due to reduced practicability, the surgeons' compliance with guidelines remains relatively low. Surgical treatment strategies can rely on randomized clinical trials (RCTs) in approximately 20% of the surgical procedures and on non-randomized trials in approximately 70% of the cases. No evidence is given in approximately 10% of the cases. Specific problems of implementation of EBM in surgical disciplines are represented by the difficulty of standardized procedures, the heterogeneity of the population, the impossibility to conduct double-blinded RCTs, a low statistical power, and a publication bias. Since individual diseases cannot be reduced to surgical cases manageable only by the application of guidelines, adequate treatment of individual patients requires the critical application of both external evidence and surgeon expertise (internal evidence).

  9. The Relationship between Water, Sanitation and Schistosomiasis: A Systematic Review and Meta-analysis

    PubMed Central

    Grimes, Jack E. T.; Croll, David; Harrison, Wendy E.; Utzinger, Jürg; Freeman, Matthew C.; Templeton, Michael R.

    2014-01-01

    Background Access to “safe” water and “adequate” sanitation are emphasized as important measures for schistosomiasis control. Indeed, the schistosomes' lifecycles suggest that their transmission may be reduced through safe water and adequate sanitation. However, the evidence has not previously been compiled in a systematic review. Methodology We carried out a systematic review and meta-analysis of studies reporting schistosome infection rates in people who do or do not have access to safe water and adequate sanitation. PubMed, Web of Science, Embase, and the Cochrane Library were searched from inception to 31 December 2013, without restrictions on year of publication or language. Studies' titles and abstracts were screened by two independent assessors. Papers deemed of interest were read in full and appropriate studies included in the meta-analysis. Publication bias was assessed through the visual inspection of funnel plots and through Egger's test. Heterogeneity of datasets within the meta-analysis was quantified using Higgins' I2. Principal Findings Safe water supplies were associated with significantly lower odds of schistosomiasis (odds ratio (OR) = 0.53, 95% confidence interval (CI): 0.47–0.61). Adequate sanitation was associated with lower odds of Schistosoma mansoni, (OR = 0.59, 95% CI: 0.47–0.73) and Schistosoma haematobium (OR = 0.69, 95% CI: 0.57–0.84). Included studies were mainly cross-sectional and quality was largely poor. Conclusions/Significance Our systematic review and meta-analysis suggests that increasing access to safe water and adequate sanitation are important measures to reduce the odds of schistosome infection. However, most of the studies were observational and quality was poor. Hence, there is a pressing need for adequately powered cluster randomized trials comparing schistosome infection risk with access to safe water and adequate sanitation, more studies which rigorously define water and sanitation, and new research on the relationships between water, sanitation, hygiene, human behavior, and schistosome transmission. PMID:25474705

  10. Do implant overdentures improve dietary intake? A randomized clinical trial.

    PubMed

    Hamdan, N M; Gray-Donald, K; Awad, M A; Johnson-Down, L; Wollin, S; Feine, J S

    2013-12-01

    People wearing mandibular two-implant overdentures (IOD) chew food with less difficulty than those wearing conventional complete dentures (CD). However, there is still controversy over whether or not this results in better dietary intake. In this randomized clinical trials (RCT), the amounts of total dietary fiber (TDF), macronutrients, 9 micronutrients, and energy in diets consumed by persons with IOD and CD were compared. Male and female edentate patients ≥ 65 yrs (n = 255) were randomly divided into 2 groups and assigned to receive a maxillary CD and either a mandibular IOD or a CD. One year following prosthesis delivery, 217 participants (CD = 114, IOD = 103) reported the food and quantities they consumed to a registered dietician through a standard 24-hour dietary recall method. The mean and median values of TDF, macro- and micronutrients, and energy consumed by both groups were calculated and compared analytically. No significant between-group differences were found (ps > .05). Despite quality-of-life benefits from IODs, this adequately powered study reveals no evidence of nutritional advantages for independently living medically healthy edentate elders wearing two-implant mandibular overdentures over those wearing conventional complete dentures in their dietary intake at one year following prosthesis delivery.

  11. Uric acid and progression of chronic kidney disease.

    PubMed

    Weaver, Donald J

    2018-06-21

    The association between serum uric acid levels and human disease has garnered intense interest over the last decade including chronic kidney disease. Animal studies have provided evidence for a potential mechanistic role of uric acid in promoting progression of chronic kidney disease. Epidemiologic studies have also suggested an association between elevated serum uric acid levels and worsening renal function in the general population as well as in patients with chronic kidney disease. However, there is currently insufficient evidence to recommend the use of uric acid-lowering therapy to delay progression of chronic kidney disease in this patient population. Adequately powered, randomized, placebo-controlled trials are required to more precisely evaluate the risk and benefits of uric acid-lowering therapy in pediatric patients.

  12. Weight management for adolescents with intellectual and developmental disabilities: Rationale and design for an 18month randomized trial.

    PubMed

    Donnelly, J E; Ptomey, L T; Goetz, J R; Sullivan, D K; Gibson, C A; Greene, J L; Lee, R H; Mayo, M S; Honas, J J; Washburn, R A

    2016-11-01

    Adolescents with intellectual and developmental disabilities (IDD) are an underserved group in need of weight management. However, information regarding effective weight management for this group is limited, and is based primarily on results from small, non-powered, non-randomized trials that were not conducted in accordance with current weight management guidelines. Additionally, the comparative effectiveness of emerging dietary approaches, such as portion-controlled meals (PCMs) or program delivery strategies such as video chat using tablet computers have not been evaluated. Therefore, we will conduct an 18month trial to compare weight loss (6months) and maintenance (7-18months) in 123 overweight/obese adolescents with mild to moderate IDD, and a parent, randomized to a weight management intervention delivered remotely using FaceTime™ on an iPad using either a conventional meal plan diet (RD/CD) or a Stop Light diet enhanced with PCMs (RD/eSLD), or conventional diet delivered during face-to-face home visits (FTF/CD). This design will provide an adequately powered comparison of both diet (CD vs. eSLD) and delivery strategy (FTF vs. RD). Exploratory analyses will examine the influence of behavioral session attendance, compliance with recommendations for diet (energy intake), physical activity (min/day), self-monitoring of diet and physical activity, medications, and parental variables including diet quality, physical activity, baseline weight, weight change, and beliefs and attitudes regarding diet and physical activity on both weight loss and maintenance. We will also complete a cost and contingent valuation analysis to compare costs between RD and FTF delivery. Copyright © 2016. Published by Elsevier Inc.

  13. Knowledge and attitudes of nurses on pressure ulcer prevention: a cross-sectional multicenter study in Belgian hospitals.

    PubMed

    Beeckman, Dimitri; Defloor, Tom; Schoonhoven, Lisette; Vanderwee, Katrien

    2011-09-01

    Evidence-based guidelines for pressure ulcer prevention have been developed and promoted by authoritative organizations. However, nonadherence to these guidelines is frequently reported. Negative attitudes and lack of knowledge may act as barriers to using guidelines in clinical practice. To study the knowledge and attitudes of nurses about pressure ulcer prevention in Belgian hospitals and to explore the correlation between knowledge, attitudes, and the application of adequate prevention. A cross-sectional multicenter study was performed in a random sample of 14 Belgian hospitals, representing 207 wards. Out of that group, 94 wards were randomly selected (2105 patients). Clinical observations were performed to assess the adequacy of pressure ulcer prevention and pressure ulcer prevalence. From each participating ward, a random selection of at least five nurses completed an extensively validated knowledge and attitude instrument. In total, 553 nurses participated. A logistic regression analysis was performed to evaluate the correlation between knowledge, attitudes, and the application of adequate prevention. Pressure ulcer prevalence (Category I-IV) was 13.5% (284/2105). Approximately 30% (625/2105) of the patients were at risk (Bradenscore <17 and/or presence of pressure ulcer). Only 13.9% (87/625) of these patients received fully adequate prevention whilst in bed and when seated. The mean knowledge and attitude scores were 49.7% and 71.3%, respectively. The application of adequate prevention on a nursing ward was significantly correlated with the attitudes of the nurses (OR = 3.07, p = .05). No independent correlation was found between knowledge and the application of adequate prevention (OR = 0.75, p = .71). Knowledge of nurses in Belgian hospitals about the prevention of pressure ulcers is inadequate. The attitudes of nurses toward pressure ulcers are significantly correlated with the application of adequate prevention. No correlation was found between knowledge and the application of adequate prevention. Copyright ©2011 Sigma Theta Tau International.

  14. Effects of AED device features on performance by untrained laypersons.

    PubMed

    Mosesso, Vincent N; Shapiro, Alan H; Stein, Karen; Burkett, Kelly; Wang, Henry

    2009-11-01

    Our study evaluates the impact of features of automated external defibrillators (AEDs) on the performance and speed of untrained laypersons to deliver a shock and initiate CPR after a shock. This was a randomized trial of volunteer laypersons without AED or advanced medical training. Subjects were assigned to use one of six different models of AEDs on a manikin in simulated cardiac arrest. No instructions on AED operation were provided. Primary endpoints were shock delivery and elapsed time from start to shock. Secondary endpoints included time to power-on, initiation of CPR, adequacy of pad placement and subjects' ratings of ease of use (1=very easy, 5=very difficult). Most subjects (109/120; 91%) were able to deliver a shock. Median time from start of scenario to shock delivery was 79 s (IQR: 67-99). Of the 11 participants who did not deliver shock, eight never powered on the device. Time to power-on was shorter in devices with open lid (median 12s, IQR 8-27 s) and pull handle (17s, IQR 9-20s) mechanisms than with a push button (37s, IQR 18-69 s; p=0.000). Pad position on the manikin was judged adequate for 86 (77%) of the 111 subjects who placed pads. Devices which gave more detailed voice instruction for pad placement had higher rates of adequate pad position [38/39 (97%) versus 50/73 (68%), p=0.001]. With AEDs that provided step-by-step CPR instruction, 49/58 (84%) subjects began CPR compared to 26/51 (51%) with AEDs that only prompted to start CPR (p=0.01). Participants rated all the models easy to use (overall mean 1.48; individual device means 1.28-1.71). Most untrained laypersons were successful in delivering a shock. Device features had the most impact on these functions: ability and time to power-on device, adequacy of pad position and initiation of CPR.

  15. Adjusting for multiple prognostic factors in the analysis of randomised trials

    PubMed Central

    2013-01-01

    Background When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method. Methods We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome. Results Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power. Conclusions It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not generally need to depend on the method of randomisation used. Most methods of analysis work well with large sample sizes, however treating strata as random effects should be the analysis method of choice with binary or time-to-event outcomes and a small sample size. PMID:23898993

  16. Performance measurements of the first RAID prototype

    NASA Technical Reports Server (NTRS)

    Chervenak, Ann L.

    1990-01-01

    The performance is examined of Redundant Arrays of Inexpensive Disks (RAID) the First, a prototype disk array. A hierarchy of bottlenecks was discovered in the system that limit overall performance. The most serious is the memory system contention on the Sun 4/280 host CPU, which limits array bandwidth to 2.3 MBytes/sec. The array performs more successfully on small random operations, achieving nearly 300 I/Os per second before the Sun 4/280 becomes CPU limited. Other bottlenecks in the system are the VME backplane, bandwidth on the disk controller, and overheads associated with the SCSI protocol. All are examined in detail. The main conclusion is that to achieve the potential bandwidth of arrays, more powerful CPU's alone will not suffice. Just as important are adequate host memory bandwidth and support for high bandwidth on disk controllers. Current disk controllers are more often designed to achieve large numbers of small random operations, rather than high bandwidth. Operating systems also need to change to support high bandwidth from disk arrays. In particular, they should transfer data in larger blocks, and should support asynchronous I/O to improve sequential write performance.

  17. Bitter melon (Momordica charantia): a review of efficacy and safety.

    PubMed

    Basch, Ethan; Gabardi, Steven; Ulbricht, Catherine

    2003-02-15

    The pharmacology, clinical efficacy, adverse effects, drug interactions, and place in therapy of bitter melon are described. Bitter melon (Momordica charantia) is an alternative therapy that has primarily been used for lowering blood glucose levels in patients with diabetes mellitus. Components of bitter melon extract appear to have structural similarities to animal insulin. Antiviral and antineoplastic activities have also been reported in vitro. Four clinical trials found bitter melon juice, fruit, and dried powder to have a moderate hypoglycemic effect. These studies were small and were not randomized or double-blind, however. Reported adverse effects of bitter melon include hypoglycemic coma and convulsions in children, reduced fertility in mice, a favism-like syndrome, increases in gamma-glutamyltransferase and alkaline phosphatase levels in animals, and headaches. Bitter melon may have additive effects when taken with other glucose-lowering agents. Adequately powered, randomized, placebo-controlled trials are needed to properly assess safety and efficacy before bitter melon can be routinely recommended. Bitter melon may have hypoglycemic effects, but data are not sufficient to recommend its use in the absence of careful supervision and monitoring.

  18. Weight loss is associated with improvements in cognitive function among overweight and obese people: A systematic review and meta-analysis.

    PubMed

    Veronese, Nicola; Facchini, Silvia; Stubbs, Brendon; Luchini, Claudio; Solmi, Marco; Manzato, Enzo; Sergi, Giuseppe; Maggi, Stefania; Cosco, Theodore; Fontana, Luigi

    2017-01-01

    Whilst obesity is associated with a higher risk of cognitive impairment, the influence of weight loss on cognitive function in obese/overweight people is equivocal. We conducted a meta-analysis of randomized controlled trials (RCTs) and longitudinal studies evaluating the influence of voluntary weight loss on cognitive function in obese/overweight individuals. Articles were acquired from a systematic search of major databases from inception till 01/2016. A random effect meta-analysis of weight loss interventions (diet, physical activity, bariatric surgery) on different cognitive domains (memory, attention, executive functions, language and motor speed) was conducted. Twenty studies (13 longitudinal studies=551 participants; 7 RCTs=328 treated vs. 140 controls) were included. Weight loss was associated with a significant improvement in attention and memory in both longitudinal studies and RCTs, whereas executive function and language improved in longitudinal and RCT studies, respectively. In conclusion, intentional weight loss in obese/overweight people is associated with improvements in performance across various cognitive domains. Future adequately powered RCTs are required to confirm/refute these findings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Nutritively Sweetened Beverage Consumption and Body Weight: A Systematic Review and Meta-Analysis of Randomized Experiments

    PubMed Central

    Mattes, Richard D; Shikany, James M; Kaiser, Kathryn A; Allison, David B

    2010-01-01

    Nutritively sweetened beverages (NSBs) may play a role in the obesity epidemic. We abstracted data from randomized controlled trials (RCTs) and evidence-based reviews through January 2009 concerning effects of consumption of NSBs on changes in body weight and adiposity. Studies included were those 1) conducted in humans; 2) lasting at least 3 weeks; 3) incorporating random assignment of subjects to conditions that differed only in the consumption of NSBs; and 4) including an adiposity indicator as an outcome. Twelve studies met the inclusion criteria. Meta-analysis of 6 studies that added NSBs to persons’ diets showed dose-dependent increases in weight. Contrarily, meta-analysis of studies that attempted to reduce NSB consumption consistently showed no effect on BMI when all subjects were considered. Meta-analysis of studies providing access to results separately for subjects overweight at baseline showed a significant effect of a roughly 0.35 standard deviations lesser BMI change (i.e., more weight loss or less weight gain) relative to controls. The current evidence does not demonstrate conclusively that NSB consumption has uniquely contributed to obesity or that reducing NSB consumption will reduce BMI levels in general. We recommend an adequately powered RCT among overweight persons, among whom there is suggestive evidence of an effect. PMID:20524996

  20. Do Implant Overdentures Improve Dietary Intake? A Randomized Clinical Trial

    PubMed Central

    Hamdan, N.M.; Gray-Donald, K.; Awad, M.A.; Johnson-Down, L.; Wollin, S.; Feine, J.S.

    2013-01-01

    People wearing mandibular two-implant overdentures (IOD) chew food with less difficulty than those wearing conventional complete dentures (CD). However, there is still controversy over whether or not this results in better dietary intake. In this randomized clinical trials (RCT), the amounts of total dietary fiber (TDF), macronutrients, 9 micronutrients, and energy in diets consumed by persons with IOD and CD were compared. Male and female edentate patients ≥ 65 yrs (n = 255) were randomly divided into 2 groups and assigned to receive a maxillary CD and either a mandibular IOD or a CD. One year following prosthesis delivery, 217 participants (CD = 114, IOD = 103) reported the food and quantities they consumed to a registered dietician through a standard 24-hour dietary recall method. The mean and median values of TDF, macro- and micronutrients, and energy consumed by both groups were calculated and compared analytically. No significant between-group differences were found (ps > .05). Despite quality-of-life benefits from IODs, this adequately powered study reveals no evidence of nutritional advantages for independently living medically healthy edentate elders wearing two-implant mandibular overdentures over those wearing conventional complete dentures in their dietary intake at one year following prosthesis delivery (International Clinical Trials ISRCTN24273915). PMID:24158335

  1. What's in a name? The challenge of describing interventions in systematic reviews: analysis of a random sample of reviews of non-pharmacological stroke interventions

    PubMed Central

    Hoffmann, Tammy C; Walker, Marion F; Langhorne, Peter; Eames, Sally; Thomas, Emma; Glasziou, Paul

    2015-01-01

    Objective To assess, in a sample of systematic reviews of non-pharmacological interventions, the completeness of intervention reporting, identify the most frequently missing elements, and assess review authors’ use of and beliefs about providing intervention information. Design Analysis of a random sample of systematic reviews of non-pharmacological stroke interventions; online survey of review authors. Data sources and study selection The Cochrane Library and PubMed were searched for potentially eligible systematic reviews and a random sample of these assessed for eligibility until 60 (30 Cochrane, 30 non-Cochrane) eligible reviews were identified. Data collection In each review, the completeness of the intervention description in each eligible trial (n=568) was assessed by 2 independent raters using the Template for Intervention Description and Replication (TIDieR) checklist. All review authors (n=46) were invited to complete a survey. Results Most reviews were missing intervention information for the majority of items. The most incompletely described items were: modifications, fidelity, materials, procedure and tailoring (missing from all interventions in 97%, 90%, 88%, 83% and 83% of reviews, respectively). Items that scored better, but were still incomplete for the majority of reviews, were: ‘when and how much’ (in 31% of reviews, adequate for all trials; in 57% of reviews, adequate for some trials); intervention mode (in 22% of reviews, adequate for all trials; in 38%, adequate for some trials); and location (in 19% of reviews, adequate for all trials). Of the 33 (71%) authors who responded, 58% reported having further intervention information but not including it, and 70% tried to obtain information. Conclusions Most focus on intervention reporting has been directed at trials. Poor intervention reporting in stroke systematic reviews is prevalent, compounded by poor trial reporting. Without adequate intervention descriptions, the conduct, usability and interpretation of reviews are restricted and therefore, require action by trialists, systematic reviewers, peer reviewers and editors. PMID:26576811

  2. Efficacy of mindfulness meditation for smoking cessation: A systematic review and meta-analysis.

    PubMed

    Maglione, Margaret A; Maher, Alicia Ruelaz; Ewing, Brett; Colaiaco, Benjamin; Newberry, Sydne; Kandrack, Ryan; Shanman, Roberta M; Sorbero, Melony E; Hempel, Susanne

    2017-06-01

    Smokers increasingly seek alternative interventions to assist in cessation or reduction efforts. Mindfulness meditation, which facilitates detached observation and paying attention to the present moment with openness, curiosity, and acceptance, has recently been studied as a smoking cessation intervention. This review synthesizes randomized controlled trials (RCTs) of mindfulness meditation (MM) interventions for smoking cessation. Five electronic databases were searched from inception to October 2016 to identify English-language RCTs evaluating the efficacy and safety of MM interventions for smoking cessation, reduction, or a decrease in nicotine cravings. Two independent reviewers screened literature using predetermined eligibility criteria, abstracted study-level information, and assessed the quality of included studies. Meta-analyses used the Hartung-Knapp-Sidik-Jonkman method for random-effects models. The quality of evidence was assessed using the GRADE approach. Ten RCTs of MM interventions for tobacco use met inclusion criteria. Intervention duration, intensity, and comparison conditions varied considerably. Studies used diverse comparators such as the American Lung Association's Freedom from Smoking (FFS) program, quitline counseling, interactive learning, or treatment as usual (TAU). Only one RCT was rated as good quality and reported power calculations indicating sufficient statistical power. Publication bias was detected. Overall, mindfulness meditation did not have significant effects on abstinence or cigarettes per day, relative to comparator groups. The small number of studies and heterogeneity in interventions, comparators, and outcomes precluded detecting systematic differences between adjunctive and monotherapy interventions. No serious adverse events were reported. MM did not differ significantly from comparator interventions in their effects on tobacco use. Low-quality evidence, variability in study design among the small number of existing studies, and publication bias suggest that additional, high-quality adequately powered RCTs should be conducted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A cluster randomized trial of routine HIV-1 viral load monitoring in Zambia: study design, implementation, and baseline cohort characteristics.

    PubMed

    Koethe, John R; Westfall, Andrew O; Luhanga, Dora K; Clark, Gina M; Goldman, Jason D; Mulenga, Priscilla L; Cantrell, Ronald A; Chi, Benjamin H; Zulu, Isaac; Saag, Michael S; Stringer, Jeffrey S A

    2010-03-12

    The benefit of routine HIV-1 viral load (VL) monitoring of patients on antiretroviral therapy (ART) in resource-constrained settings is uncertain because of the high costs associated with the test and the limited treatment options. We designed a cluster randomized controlled trial to compare the use of routine VL testing at ART-initiation and at 3, 6, 12, and 18 months, versus our local standard of care (which uses immunological and clinical criteria to diagnose treatment failure, with discretionary VL testing when the two do not agree). Dedicated study personnel were integrated into public-sector ART clinics. We collected participant information in a dedicated research database. Twelve ART clinics in Lusaka, Zambia constituted the units of randomization. Study clinics were stratified into pairs according to matching criteria (historical mortality rate, size, and duration of operation) to limit the effect of clustering, and independently randomized to the intervention and control arms. The study was powered to detect a 36% reduction in mortality at 18 months. From December 2006 to May 2008, we completed enrollment of 1973 participants. Measured baseline characteristics did not differ significantly between the study arms. Enrollment was staggered by clinic pair and truncated at two matched sites. A large clinical trial of routing VL monitoring was successfully implemented in a dynamic and rapidly growing national ART program. Close collaboration with local health authorities and adequate reserve staff were critical to success. Randomized controlled trials such as this will likely prove valuable in determining long-term outcomes in resource-constrained settings. Clinicaltrials.gov NCT00929604.

  4. Protocol design and current status of CLIVIT: a randomized controlled multicenter relevance trial comparing clips versus ligatures in thyroid surgery

    PubMed Central

    Seiler, CM; Fröhlich, BE; Veit, JA; Gazyakan, E; Wente, MN; Wollermann, C; Deckert, A; Witte, S; Victor, N; Buchler, MW; Knaebel, HP

    2006-01-01

    Background Annually, more than 90000 surgical procedures of the thyroid gland are performed in Germany. Strategies aimed at reducing the duration of the surgical procedure are relevant to patients and the health care system especially in the context of reducing costs. However, new techniques for quick and safe hemostasis have to be tested in clinically relevance randomized controlled trials before a general recommendation can be given. The current standard for occlusion of blood vessels in thyroid surgery is ligatures. Vascular clips may be a safe alternative but have not been investigated in a large RCT. Methods/design CLIVIT (Clips versus Ligatures in Thyroid Surgery) is an investigator initiated, multicenter, patient-blinded, two-group parallel relevance randomized controlled trial designed by the Study Center of the German Surgical Society. Patients scheduled for elective resection of at least two third of the gland for benign thyroid disease are eligible for participation. After surgical exploration patients are randomized intraoperatively into either the conventional ligature group, or into the clip group. The primary objective is to test for a relevant reduction in operating time (at least 15 min) when using the clip technique. Since April 2004, 121 of the totally required 420 patients were randomized in five centers. Discussion As in all trials the different forms of bias have to be considered, and as in this case, a surgical trial, the role of surgical expertise plays a key role, and will be documented and analyzed separately. This is the first randomized controlled multicenter relevance trial to compare different vessel occlusion techniques in thyroid surgery with adequate power and other detailed information about the design as well as framework. If significant, the results might be generalized and may change the current surgical practice. PMID:16948853

  5. 18 CFR 284.503 - Market-power determination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

  6. 18 CFR 284.503 - Market-power determination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

  7. 18 CFR 284.503 - Market-power determination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

  8. 18 CFR 284.503 - Market-power determination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

  9. Abnormal Resting-State Quantitative Electroencephalogram in Children With Central Auditory Processing Disorder: A Pilot Study

    PubMed Central

    Milner, Rafał; Lewandowska, Monika; Ganc, Małgorzata; Włodarczyk, Elżbieta; Grudzień, Diana; Skarżyński, Henryk

    2018-01-01

    In this study, we showed an abnormal resting-state quantitative electroencephalogram (QEEG) pattern in children with central auditory processing disorder (CAPD). Twenty-seven children (16 male, 11 female; mean age = 10.7 years) with CAPD and no symptoms of other developmental disorders, as well as 23 age- and sex-matched, typically developing children (TDC, 11 male, 13 female; mean age = 11.8 years) underwent examination of central auditory processes (CAPs) and QEEG evaluation consisting of two randomly presented blocks of “Eyes Open” (EO) or “Eyes Closed” (EC) recordings. Significant correlations between individual frequency band powers and CAP tests performance were found. The QEEG studies revealed that in CAPD relative to TDC there was no effect of decreased delta absolute power (1.5–4 Hz) in EO compared to the EC condition. Furthermore, children with CAPD showed increased theta power (4–8 Hz) in the frontal area, a tendency toward elevated theta power in EO block, and reduced low-frequency beta power (12–15 Hz) in the bilateral occipital and the left temporo-occipital regions for both EO and EC conditions. Decreased middle-frequency beta power (15–18 Hz) in children with CAPD was observed only in the EC block. The findings of the present study suggest that QEEG could be an adequate tool to discriminate children with CAPD from normally developing children. Correlation analysis shows relationship between the individual EEG resting frequency bands and the CAPs. Increased power of slow waves and decreased power of fast rhythms could indicate abnormal functioning (hypoarousal of the cortex and/or an immaturity) of brain areas not specialized in auditory information processing.

  10. 10-year trend in quantity and quality of pediatric randomized controlled trials published in mainland China: 2002–2011

    PubMed Central

    2013-01-01

    Background Quality assessment of pediatric randomized controlled trials (RCTs) in China is limited. The aim of this study was to evaluate the quantitative trends and quality indicators of RCTs published in mainland China over a recent 10-year period. Methods We individually searched all 17 available pediatric journals published in China from January 1, 2002 to December 30, 2011 to identify RCTs of drug treatment in participants under the age of 18 years. The quality was evaluated according to the Cochrane quality assessment protocol. Results Of 1287 journal issues containing 44398 articles, a total of 2.4% (1077/44398) articles were included in the analysis. The proportion of RCTs increased from 0.28% in 2002 to 0.32% in 2011. Individual sample sizes ranged from 10 to 905 participants (median 81 participants); 2.3% of the RCTs were multiple center trials; 63.9% evaluated Western medicine, 32.5% evaluated traditional Chinese medicine; 15% used an adequate method of random sequence generation; and 10.4% used a quasi-random method for randomization. Only 1% of the RCTs reported adequate allocation concealment and 0.6% reported the method of blinding. The follow-up period was from 7 days to 96 months, with a median of 7.5 months. There was incomplete outcome data reported in 8.3%, of which 4.5% (4/89) used intention-to-treat analysis. Only 0.4% of the included trials used adequate random sequence allocation, concealment and blinding. The articles published from 2007 to 2011 revealed an improvement in the randomization method compared with articles published from 2002 to 2006 (from 2.7% to 23.6%, p = 0.000). Conclusions In mainland China, the quantity of RCTs did not increase in the pediatric population, and the general quality was relatively poor. Quality improvements were suboptimal in the later 5 years. PMID:23914882

  11. Rationale for the Assessment of Metoprolol in the Prevention of Vasovagal Syncope in Aging Subjects Trial (POST5).

    PubMed

    Raj, Satish R; Faris, Peter D; Semeniuk, Lisa; Manns, Braden; Krahn, Andrew D; Morillo, Carlos A; Benditt, David G; Sheldon, Robert S

    2016-04-01

    Vasovagal syncope (VVS) is a common problem associated with a poor quality of life, which improves when syncope frequency is reduced. Effective pharmacological therapies for VVS are lacking. Metoprolol is a β-adrenergic receptor antagonist that is ineffective in younger patients, but may benefit older (≥40 years) VVS patients. Given the limited therapeutic options, a placebo-controlled clinical trial of metoprolol for the prevention of VVS in older patients is needed. The POST5 is a multicenter, international, randomized, placebo-controlled study of metoprolol in the prevention of VVS in patients ≥40 years old. The primary endpoint is the time to first recurrence of syncope. Patients will be randomized 1:1 to receive metoprolol 25 to 100 mg BID or matching placebo, and followed up for 1 year. Secondary end points include syncope frequency, presyncope, quality of life, and cost analysis. Primary analysis will be intention to treat, with a secondary on-treatment analysis. A sample size of 222, split equally between the groups achieves 85% power to detect a hazard rate of 0.3561 when the event rates are 50% and 30% in the placebo and metoprolol arms. Allowing for 10% dropout, we propose to enroll 248 patients. This study will be the first adequately powered trial to determine whether metoprolol is effective in preventing VVS in patients ≥40 years. If effective, metoprolol may become the first line pharmacological therapy for these patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. 9 CFR 3.50 - Facilities, general.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...

  13. 9 CFR 3.50 - Facilities, general.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...

  14. 9 CFR 3.50 - Facilities, general.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of Rabbits...) Water and electric power. Reliable and adequate electric power, if required to comply with other...

  15. Uridine monophosphate, folic acid and vitamin B12 in patients with symptomatic peripheral entrapment neuropathies.

    PubMed

    Negrão, Luis; Nunes, Paula

    2016-01-01

    Carpal tunnel syndrome is the most common type of peripheral entrapment neuropathy. We performed an exploratory, open-label, multicenter, observational study of 48 patients with peripheral entrapment neuropathy. Patients received a daily capsule of uridine monophosphate, folic acid + vitamin B12 for 2 months and were evaluated using the Pain DETECT questionnaire. The global score for pain decreased from 17.3 ± 5.9 at baseline to 10.3 ± 6.1 at the final evaluation (p < 0.001). Concomitant analgesic and anti-inflammatory treatment was stopped or the dose reduced in 77.4% of patients. Uridine monophosphate + folic acid + vitamin B12 reduced total pain score, intensity and characterization of pain and associated symptoms. These results should be tested in a well-designed, adequately powered randomized controlled trial.

  16. Recombinant activated factor VII for bleeding in patients without inherited bleeding disorders.

    PubMed

    Selin, S; Tejani, A

    2006-03-01

    (1) Recombinant activated factor VII (rFVIIa) is licensed in Canada for the prevention and treatment of bleeding in hemophiliacs, but it is increasingly used to control bleeding in non-hemophilic patients during surgery, or during treatment for severe trauma or intracerebral hemorrhage (ICH). (2) In one clinical trial, there was a significant reduction in mortality among patients with ICH treated with rFVIIa. In another trial, administration of rFVIIa significantly reduced the number of trauma patients needing massive blood transfusions although there was no significant difference in mortality. (3) Adequately powered randomized controlled trials are needed to clarify the efficacy and safety of rFVIIa for non-bleeding disorder indications. Phase III trials in ICH and trauma are underway. (4) There is potential for non-hemophilic use, particularly if clinical efficacy and cost effectiveness are established.

  17. 14 CFR 171.113 - Installation requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...

  18. 14 CFR 171.113 - Installation requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...

  19. 14 CFR 171.113 - Installation requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... facilities. (c) The facility must have a reliable source of suitable primary power, either from a power distribution system or locally generated. Also, adequate power capacity must be provided for operation of test... a facility will be required to have standby power for the SDF and monitor accessories to supplement...

  20. 30 CFR 75.517 - Power wires and cables; insulation and protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...

  1. 30 CFR 75.517 - Power wires and cables; insulation and protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...

  2. 30 CFR 75.517 - Power wires and cables; insulation and protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...

  3. 30 CFR 75.517 - Power wires and cables; insulation and protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...

  4. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... power conductors and telephone wires. 77.508 Section 77.508 Mineral Resources MINE SAFETY AND HEALTH... arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...

  5. 30 CFR 75.517 - Power wires and cables; insulation and protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Power wires and cables; insulation and...-General § 75.517 Power wires and cables; insulation and protection. [Statutory Provisions] Power wires and cables, except trolley wires, trolley feeder wires, and bare signal wires, shall be insulated adequately...

  6. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... power conductors and telephone wires. 77.508 Section 77.508 Mineral Resources MINE SAFETY AND HEALTH... arresters, ungrounded and exposed power conductors and telephone wires. All ungrounded, exposed power conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...

  7. 75 FR 76498 - Firstenergy Nuclear Operating Company, Davis-Besse Nuclear Power Station; Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ... Company, Davis-Besse Nuclear Power Station; Environmental Assessment And Finding of No Significant Impact... operation of the Davis-Besse Nuclear Power Station, Unit 1 (DBNPS), located in Ottawa County, Ohio. In... the reactor coolant pressure boundary of light-water nuclear power reactors provide adequate margins...

  8. Increased calcium absorption from synthetic stable amorphous calcium carbonate: Double-blind randomized crossover clinical trial in post-menopausal women

    USDA-ARS?s Scientific Manuscript database

    Calcium supplementation is a widely recognized strategy for achieving adequate calcium intake. We designed this blinded, randomized, crossover interventional trial to compare the bioavailability of a new stable synthetic amorphous calcium carbonate (ACC) with that of crystalline calcium carbonate (C...

  9. Clinical trials bureaucracy: unintended consequences of well-intentioned policy.

    PubMed

    Califf, Robert M

    2006-01-01

    As randomized controlled trials have become the 'gold standard' for medical research, a complex regulatory structure for the conduct of clinical trials has emerged. However, this structure has not been adequately assessed to ensure that regulations governing human subjects research actually produce the desired effects. Our purpose is to identify some of the major shortcomings in the current regulatory system of human clinical trials oversight, and to propose some potential solutions to these problems. We discuss the evolution of the current US regulatory environment and its application in the context of several widely-used drug therapies. Despite numerous randomized controlled trials, performed within a structure of extensive documentation and data collection, serious shortcomings in a number of pharmaceutical therapies were not detected until after the drugs were approved and widely adopted by clinicians. The current system of regulatory bureaucracy in clinical trials has led to an extremely expensive research paradigm that, in spite of complex systems of oversight and exhaustive data collection, cannot be shown to adequately ensure the integrity of the research process and the protection of human research subjects. Some parts of the system, including Research Ethics Review Boards, may not be well-suited to carrying out their core mission of overseeing research conduct, and other aspects of clinical trials regulatory structure, such as monitoring/auditing review and adverse event reporting, may constitute a waste of money and resources. Misdirected data collection and adverse events reporting divert valuable resources and hamper development of large, simple clinical trials powered to definitively answer important research questions. Careful scrutiny of the utility of current or proposed regulatory schemes is required to ensure the integrity of human subjects research and to enhance the effectiveness of research dollars.

  10. Study protocol for Log2Lose: A feasibility randomized controlled trial to evaluate financial incentives for dietary self-monitoring and interim weight loss in adults with obesity.

    PubMed

    Voils, Corrine I; Levine, Erica; Gierisch, Jennifer M; Pendergast, Jane; Hale, Sarah L; McVay, Megan A; Reed, Shelby D; Yancy, William S; Bennett, Gary; Strawbridge, Elizabeth M; White, Allison C; Shaw, Ryan J

    2018-02-01

    The obesity epidemic has negative physical, psychological, and financial consequences. Despite the existence of effective behavioral weight loss interventions, many individuals do not achieve adequate weight loss, and most regain lost weight in the year following intervention. We report the rationale and design for a 2×2 factorial study that involves financial incentives for dietary self-monitoring (yes vs. no) and/or interim weight loss (yes vs. no). Outpatients with obesity participate in a 24-week, group-based weight loss intervention. All participants are asked to record their daily dietary and liquid intake on a smartphone application (app) and to weigh themselves daily at home on a study-provided cellular scale. An innovative information technology (IT) solution collates dietary data from the app and weight from the scale. Using these data, an algorithm classifies participants weekly according to whether they met their group's criteria to receive a cash reward ranging from $0 to $30 for dietary self-monitoring and/or interim weight loss. Notice of the reward is provided via text message, and credit is uploaded to a gift card. This pilot study will provide information on the feasibility of using this novel IT solution to provide variable-ratio financial incentives in real time via its effects on recruitment, intervention adherence, retention, and cost. This study will provide the foundation for a comprehensive, adequately-powered, randomized controlled trial to promote short-term weight loss and long-term weight maintenance. If efficacious, this approach could reduce the prevalence, adverse outcomes, and costs of obesity for millions of Americans. Clinicaltrials.gov registration: NCT02691260. Published by Elsevier Inc.

  11. Linear Combinations of Multiple Outcome Measures to Improve the Power of Efficacy Analysis ---Application to Clinical Trials on Early Stage Alzheimer Disease

    PubMed Central

    Xiong, Chengjie; Luo, Jingqin; Morris, John C; Bateman, Randall

    2018-01-01

    Modern clinical trials on Alzheimer disease (AD) focus on the early symptomatic stage or even the preclinical stage. Subtle disease progression at the early stages, however, poses a major challenge in designing such clinical trials. We propose a multivariate mixed model on repeated measures to model the disease progression over time on multiple efficacy outcomes, and derive the optimum weights to combine multiple outcome measures by minimizing the sample sizes to adequately power the clinical trials. A cross-validation simulation study is conducted to assess the accuracy for the estimated weights as well as the improvement in reducing the sample sizes for such trials. The proposed methodology is applied to the multiple cognitive tests from the ongoing observational study of the Dominantly Inherited Alzheimer Network (DIAN) to power future clinical trials in the DIAN with a cognitive endpoint. Our results show that the optimum weights to combine multiple outcome measures can be accurately estimated, and that compared to the individual outcomes, the combined efficacy outcome with these weights significantly reduces the sample size required to adequately power clinical trials. When applied to the clinical trial in the DIAN, the estimated linear combination of six cognitive tests can adequately power the clinical trial. PMID:29546251

  12. 14 CFR 25.1707 - System separation: EWIS.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

  13. 14 CFR 25.1707 - System separation: EWIS.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

  14. 14 CFR 25.1707 - System separation: EWIS.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

  15. 14 CFR 25.1707 - System separation: EWIS.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

  16. 14 CFR 25.1707 - System separation: EWIS.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

  17. U.S. National Womens Agenda

    ERIC Educational Resources Information Center

    Social Policy, 1976

    1976-01-01

    Priorities on the agenda include fair representation and participation in the political process, equal education and training, meaningful work and adequate compensation, equal access to economic power, adequate housing, physical safety, and fair treatment by and equal access to media and the arts. (Author/AM)

  18. The Statistical Power of the Cluster Randomized Block Design with Matched Pairs--A Simulation Study

    ERIC Educational Resources Information Center

    Dong, Nianbo; Lipsey, Mark

    2010-01-01

    This study uses simulation techniques to examine the statistical power of the group- randomized design and the matched-pair (MP) randomized block design under various parameter combinations. Both nearest neighbor matching and random matching are used for the MP design. The power of each design for any parameter combination was calculated from…

  19. 30 CFR 57.12008 - Insulation and fittings for power wires and cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulation and fittings for power wires and... NONMETAL MINES Electricity Surface and Underground § 57.12008 Insulation and fittings for power wires and cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical...

  20. 30 CFR 57.12008 - Insulation and fittings for power wires and cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulation and fittings for power wires and... NONMETAL MINES Electricity Surface and Underground § 57.12008 Insulation and fittings for power wires and cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical...

  1. A robust and efficient statistical method for genetic association studies using case and control samples from multiple cohorts

    PubMed Central

    2013-01-01

    Background The theoretical basis of genome-wide association studies (GWAS) is statistical inference of linkage disequilibrium (LD) between any polymorphic marker and a putative disease locus. Most methods widely implemented for such analyses are vulnerable to several key demographic factors and deliver a poor statistical power for detecting genuine associations and also a high false positive rate. Here, we present a likelihood-based statistical approach that accounts properly for non-random nature of case–control samples in regard of genotypic distribution at the loci in populations under study and confers flexibility to test for genetic association in presence of different confounding factors such as population structure, non-randomness of samples etc. Results We implemented this novel method together with several popular methods in the literature of GWAS, to re-analyze recently published Parkinson’s disease (PD) case–control samples. The real data analysis and computer simulation show that the new method confers not only significantly improved statistical power for detecting the associations but also robustness to the difficulties stemmed from non-randomly sampling and genetic structures when compared to its rivals. In particular, the new method detected 44 significant SNPs within 25 chromosomal regions of size < 1 Mb but only 6 SNPs in two of these regions were previously detected by the trend test based methods. It discovered two SNPs located 1.18 Mb and 0.18 Mb from the PD candidates, FGF20 and PARK8, without invoking false positive risk. Conclusions We developed a novel likelihood-based method which provides adequate estimation of LD and other population model parameters by using case and control samples, the ease in integration of these samples from multiple genetically divergent populations and thus confers statistically robust and powerful analyses of GWAS. On basis of simulation studies and analysis of real datasets, we demonstrated significant improvement of the new method over the non-parametric trend test, which is the most popularly implemented in the literature of GWAS. PMID:23394771

  2. Theoretical study and design of third-order random fiber laser

    NASA Astrophysics Data System (ADS)

    Xie, Zhaoxin; Shi, Wei; Fu, Shijie; Sheng, Quan; Yao, Jianquan

    2018-02-01

    We present result of achieving a random fiber laser at a working wavelength of 1178nm while pumping at 1018nm. The laser power is realized by 200m long cavity which includes three high reflectivity fiber Bragg gratings. This simple and efficient random fiber laser could provide a novel approach to realize low-threshold and high-efficiency 1178nm long wavelength laser. We theoretically analyzed the laser power in random fiber lasers at different pump power by changing three high reflectivity fiber Bragg gratings. We also calculated the forward and backward power of 1st-order stokes, 2nd-order stokes, 3rd-order stokes. With the theoretical analysis, we optimize the cavity's reflectivity to get higher laser power output. The forward random laser exhibits larger gain, the backward random laser has lower gain. By controlling the value of angle-cleaved end fiber's reflectivity to 3×10-7, when the high reflectivity increases from 0.01 to 0.99, the laser power increases, using this proposed configuration, the 1178nm random laser can be generated easily and stably.

  3. Digital servo control of random sound fields

    NASA Technical Reports Server (NTRS)

    Nakich, R. B.

    1973-01-01

    It is necessary to place number of sensors at different positions in sound field to determine actual sound intensities to which test object is subjected. It is possible to determine whether specification is being met adequately or exceeded. Since excitation is of random nature, signals are essentially coherent and it is impossible to obtain true average.

  4. Power Plant Water Intake Assessment.

    ERIC Educational Resources Information Center

    Zeitoun, Ibrahim H.; And Others

    1980-01-01

    In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

  5. Anterior or posterior walkers for children with cerebral palsy? A systematic review.

    PubMed

    Poole, Marilyn; Simkiss, Doug; Rose, Alice; Li, François-Xavier

    2018-05-01

    To review the literature comparing use of anterior and posterior walkers (PW's) by children with cerebral palsy (CP) to determine which walker type is preferable. Electronic databases were searched using pre-defined terms by two independent reviewers. Reference lists of included studies were hand searched. Studies published between 1985 and 2016 comparing use of anterior and PW's by children with CP were included. All study designs and outcomes were accepted. Risk of bias was assessed using the "Quality assessment standard for a cross-over study". Quality of evidence was evaluated using GRADE. Six studies were analysed. All studies had small sample sizes. A total of 4/6 studies were randomized. A total of 4/6 had high risk of bias. Outcomes included velocity, pelvic tilt, hip flexion, knee flexion, step length, stride length, cadence, double stance time, oxygen cost and participant/parental preference. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a PW, however, GRADE quality was very low for all outcomes and there was heterogeneity between studies. The majority of participants and parents preferred the PW. Heterogeneity and low quality of existing evidence prevented recommendation of one walker type. Well-designed studies with adequate power are needed to inform clinical recommendations. Implications for rehabilitation Clinical recommendations cannot be made for whether anterior or posterior walkers are preferable for children with cerebral palsy based on the existing evidence. Velocity, trunk flexion/pelvic tilt, and stability may be improved by using a posterior walker. The majority of walking aid users and their parents preferred posterior walkers. Adequately powered studies designed to minimize bias are needed.

  6. Importance of hard coal in electricity generation in Poland

    NASA Astrophysics Data System (ADS)

    Plewa, Franciszek; Strozik, Grzegorz

    2017-11-01

    Polish energy sector is facing a number of challenges, in particular as regards the reconstruction of production potential, diversification of energy sources, environmental issues, adequate fuels supplies and other. Mandatory implementation of Europe 2020 strategy in terms of “3x20” targets (20% reduction of greenhouse gases, 20% of energy from renewable sources, and 20% increase of efficiency in energy production) requires fast decision, which have to be coordinated with energetic safety issues, increasing demands for electric energy, and other factors. In Poland almost 80% of power is installed in coal fired power plants and energy from hard coals is relatively less expensive than from other sources, especially renewable. The most of renewable energy sources power plants are unable to generate power in amounts which can be competitive with coal fires power stations and are highly expensive, what leads o high prices of electric energy. Alternatively, new generation of coal fired coal power plants is able to significantly increase efficiency, reduce carbon dioxide emission, and generate less expensive electric power in amounts adequate to the demands of a country.

  7. Are Substance Use Prevention Programs More Effective in Schools Making Adequate Yearly Progress? A Study of Project ALERT

    ERIC Educational Resources Information Center

    Clark, Heddy Kovach; Ringwalt, Chris L.; Shamblen, Stephen R.; Hanley, Sean M.; Flewelling, Robert L.

    2011-01-01

    This exploratory study sought to determine if a popular school-based drug prevention program might be effective in schools that are making adequate yearly progress (AYP). Thirty-four schools with grades 6 through 8 in 11 states were randomly assigned either to receive Project ALERT (n = 17) or to a control group (n = 17); of these, 10 intervention…

  8. Flight test evaluation of predicted light aircraft drag, performance, and stability

    NASA Technical Reports Server (NTRS)

    Smetana, F. O.; Fox, S. R.

    1979-01-01

    A technique was developed which permits simultaneous extraction of complete lift, drag, and thrust power curves from time histories of a single aircraft maneuver such as a pull up (from V max to V stall) and pushover (to V max for level flight). The technique, which is an extension of nonlinear equations of motion of the parameter identification methods of Iliff and Taylor and includes provisions for internal data compatibility improvement as well, was shown to be capable of correcting random errors in the most sensitive data channel and yielding highly accurate results. Flow charts, listings, sample inputs and outputs for the relevant routines are provided as appendices. This technique was applied to flight data taken on the ATLIT aircraft. Lack of adequate knowledge of the correct full throttle thrust horsepower true airspeed variation and considerable internal data inconsistency made it impossible to apply the trajectory matching features of the technique.

  9. An Evaluation of Two Methods for Generating Synthetic HL7 Segments Reflecting Real-World Health Information Exchange Transactions

    PubMed Central

    Mwogi, Thomas S.; Biondich, Paul G.; Grannis, Shaun J.

    2014-01-01

    Motivated by the need for readily available data for testing an open-source health information exchange platform, we developed and evaluated two methods for generating synthetic messages. The methods used HL7 version 2 messages obtained from the Indiana Network for Patient Care. Data from both methods were analyzed to assess how effectively the output reflected original ‘real-world’ data. The Markov Chain method (MCM) used an algorithm based on transitional probability matrix while the Music Box model (MBM) randomly selected messages of particular trigger type from the original data to generate new messages. The MBM was faster, generated shorter messages and exhibited less variation in message length. The MCM required more computational power, generated longer messages with more message length variability. Both methods exhibited adequate coverage, producing a high proportion of messages consistent with original messages. Both methods yielded similar rates of valid messages. PMID:25954458

  10. 18 CFR 39.3 - Electric Reliability Organization certification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... operators of the Bulk-Power System, and other interested parties for improvement of the Electric Reliability... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Electric Reliability..., Reliability Standards that provide for an adequate level of reliability of the Bulk-Power System, and (2) Has...

  11. 14 CFR 171.271 - Installation requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... generated. Adequate power capacity must be provided for the operation of test and working equipment of the... restoration of power, the batteries must be restored to full charge within 24 hours. When primary power is... battery must permit continuation of normal operation for at least two hours under the normal operating...

  12. Random Variation in Student Performance by Class Size: Implications of NCLB in Rural Pennsylvania

    ERIC Educational Resources Information Center

    Goetz, Stephan J.

    2005-01-01

    Schools that fail to make "adequate yearly progress" under NCLB face sanctions and may lose students to other schools. In smaller schools, random yearly variation in innate student ability and behavior can cause changes in scores that are beyond the influence of teachers. This study examines changes in reading and math scores across…

  13. Enrichment methods provide a feasible approach to comprehensive and adequately powered investigations of the brain methylome

    PubMed Central

    Chan, Robin F.; Shabalin, Andrey A.; Xie, Lin Y.; Adkins, Daniel E.; Zhao, Min; Turecki, Gustavo; Clark, Shaunna L.; Aberg, Karolina A.

    2017-01-01

    Abstract Methylome-wide association studies are typically performed using microarray technologies that only assay a very small fraction of the CG methylome and entirely miss two forms of methylation that are common in brain and likely of particular relevance for neuroscience and psychiatric disorders. The alternative is to use whole genome bisulfite (WGB) sequencing but this approach is not yet practically feasible with sample sizes required for adequate statistical power. We argue for revisiting methylation enrichment methods that, provided optimal protocols are used, enable comprehensive, adequately powered and cost-effective genome-wide investigations of the brain methylome. To support our claim we use data showing that enrichment methods approximate the sensitivity obtained with WGB methods and with slightly better specificity. However, this performance is achieved at <5% of the reagent costs. Furthermore, because many more samples can be sequenced simultaneously, projects can be completed about 15 times faster. Currently the only viable option available for comprehensive brain methylome studies, enrichment methods may be critical for moving the field forward. PMID:28334972

  14. Toward a functional definition of a "rare disease" for regulatory authorities and funding agencies.

    PubMed

    Clarke, Joe T R; Coyle, Doug; Evans, Gerald; Martin, Janet; Winquist, Eric

    2014-12-01

    The designation of a disease as "rare" is associated with some substantial benefits for companies involved in new drug development, including expedited review by regulatory authorities and relaxed criteria for reimbursement. How "rare disease" is defined therefore has major financial implications, both for pharmaceutical companies and for insurers or public drug reimbursement programs. All existing definitions are based, somewhat arbitrarily, on disease incidence or prevalence. What is proposed here is a functional definition of rare based on an assessment of the feasibility of measuring the efficacy of a new treatment in conventional randomized controlled trials, to inform regulatory authorities and funding agencies charged with assessing new therapies being considered for public funding. It involves a five-step process, involving significant negotiations between patient advocacy groups, pharmaceutical companies, physicians, and public drug reimbursement programs, designed to establish the feasibility of carrying out a randomized controlled trial with sufficient statistical power to show a clinically significant treatment effect. The steps are as follows: 1) identification of a specific disease, including appropriate genetic definition; 2) identification of clinically relevant outcomes to evaluate efficacy; 3) establishment of the inherent variability of measurements of clinically relevant outcomes; 4) calculation of the sample size required to assess the efficacy of a new treatment with acceptable statistical power; and 5) estimation of the difficulty of recruiting an adequate sample size given the estimated prevalence or incidence of the disorder in the population and the inclusion criteria to be used. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  15. An Empirical Study of Design Parameters for Assessing Differential Impacts for Students in Group Randomized Trials.

    PubMed

    Jaciw, Andrew P; Lin, Li; Ma, Boya

    2016-10-18

    Prior research has investigated design parameters for assessing average program impacts on achievement outcomes with cluster randomized trials (CRTs). Less is known about parameters important for assessing differential impacts. This article develops a statistical framework for designing CRTs to assess differences in impact among student subgroups and presents initial estimates of critical parameters. Effect sizes and minimum detectable effect sizes for average and differential impacts are calculated before and after conditioning on effects of covariates using results from several CRTs. Relative sensitivities to detect average and differential impacts are also examined. Student outcomes from six CRTs are analyzed. Achievement in math, science, reading, and writing. The ratio of between-cluster variation in the slope of the moderator divided by total variance-the "moderator gap variance ratio"-is important for designing studies to detect differences in impact between student subgroups. This quantity is the analogue of the intraclass correlation coefficient. Typical values were .02 for gender and .04 for socioeconomic status. For studies considered, in many cases estimates of differential impact were larger than of average impact, and after conditioning on effects of covariates, similar power was achieved for detecting average and differential impacts of the same size. Measuring differential impacts is important for addressing questions of equity, generalizability, and guiding interpretation of subgroup impact findings. Adequate power for doing this is in some cases reachable with CRTs designed to measure average impacts. Continuing collection of parameters for assessing differential impacts is the next step. © The Author(s) 2016.

  16. Efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome: systematic review and meta-analysis.

    PubMed

    Schaefert, Rainer; Klose, Petra; Moser, Gabriele; Häuser, Winfried

    2014-06-01

    To assess the efficacy, tolerability, and safety of hypnosis in adult irritable bowel syndrome by a meta-analysis of randomized controlled trials. Studies were identified by a literature search of the databases Allied and Complementary Medicine Database, Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, PubMed, PsycINFO, and Scopus (from inception to June 30, 2013). Primary outcomes were adequate symptom relief, global gastrointestinal score, and safety. Summary relative risks (RRs) with number needed to treat (NNT) and standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were calculated using random-effects models. Eight randomized controlled trials with a total of 464 patients and a median of 8.5 (7-12) hypnosis sessions over a median of 12 (5-12) weeks were included into the analysis. At the end of therapy, hypnosis was superior to control conditions in producing adequate symptom relief (RR, 1.69 [95% CI = 1.14-2.51]; NNT, 5 [3-10]) and in reducing global gastrointestinal score (SMD, 0.32 [95% CI = -0.56 to -0.08]). At long-term follow-up, hypnosis was superior to controls in adequate symptom relief (RR, 2.17 [95% CI = 1.22-3.87]; NNT, 3 [2-10]), but not in reducing global gastrointestinal score (SMD, -0.57 [-1.40 to 0.26]). One (0.4%) of 238 patients in the hypnosis group dropped out due to an adverse event (panic attack). This meta-analysis demonstrated that hypnosis was safe and provided long-term adequate symptom relief in 54% of patients with irritable bowel syndrome refractory to conventional therapy.

  17. Power estimation using simulations for air pollution time-series studies

    PubMed Central

    2012-01-01

    Background Estimation of power to assess associations of interest can be challenging for time-series studies of the acute health effects of air pollution because there are two dimensions of sample size (time-series length and daily outcome counts), and because these studies often use generalized linear models to control for complex patterns of covariation between pollutants and time trends, meteorology and possibly other pollutants. In general, statistical software packages for power estimation rely on simplifying assumptions that may not adequately capture this complexity. Here we examine the impact of various factors affecting power using simulations, with comparison of power estimates obtained from simulations with those obtained using statistical software. Methods Power was estimated for various analyses within a time-series study of air pollution and emergency department visits using simulations for specified scenarios. Mean daily emergency department visit counts, model parameter value estimates and daily values for air pollution and meteorological variables from actual data (8/1/98 to 7/31/99 in Atlanta) were used to generate simulated daily outcome counts with specified temporal associations with air pollutants and randomly generated error based on a Poisson distribution. Power was estimated by conducting analyses of the association between simulated daily outcome counts and air pollution in 2000 data sets for each scenario. Power estimates from simulations and statistical software (G*Power and PASS) were compared. Results In the simulation results, increasing time-series length and average daily outcome counts both increased power to a similar extent. Our results also illustrate the low power that can result from using outcomes with low daily counts or short time series, and the reduction in power that can accompany use of multipollutant models. Power estimates obtained using standard statistical software were very similar to those from the simulations when properly implemented; implementation, however, was not straightforward. Conclusions These analyses demonstrate the similar impact on power of increasing time-series length versus increasing daily outcome counts, which has not previously been reported. Implementation of power software for these studies is discussed and guidance is provided. PMID:22995599

  18. Power estimation using simulations for air pollution time-series studies.

    PubMed

    Winquist, Andrea; Klein, Mitchel; Tolbert, Paige; Sarnat, Stefanie Ebelt

    2012-09-20

    Estimation of power to assess associations of interest can be challenging for time-series studies of the acute health effects of air pollution because there are two dimensions of sample size (time-series length and daily outcome counts), and because these studies often use generalized linear models to control for complex patterns of covariation between pollutants and time trends, meteorology and possibly other pollutants. In general, statistical software packages for power estimation rely on simplifying assumptions that may not adequately capture this complexity. Here we examine the impact of various factors affecting power using simulations, with comparison of power estimates obtained from simulations with those obtained using statistical software. Power was estimated for various analyses within a time-series study of air pollution and emergency department visits using simulations for specified scenarios. Mean daily emergency department visit counts, model parameter value estimates and daily values for air pollution and meteorological variables from actual data (8/1/98 to 7/31/99 in Atlanta) were used to generate simulated daily outcome counts with specified temporal associations with air pollutants and randomly generated error based on a Poisson distribution. Power was estimated by conducting analyses of the association between simulated daily outcome counts and air pollution in 2000 data sets for each scenario. Power estimates from simulations and statistical software (G*Power and PASS) were compared. In the simulation results, increasing time-series length and average daily outcome counts both increased power to a similar extent. Our results also illustrate the low power that can result from using outcomes with low daily counts or short time series, and the reduction in power that can accompany use of multipollutant models. Power estimates obtained using standard statistical software were very similar to those from the simulations when properly implemented; implementation, however, was not straightforward. These analyses demonstrate the similar impact on power of increasing time-series length versus increasing daily outcome counts, which has not previously been reported. Implementation of power software for these studies is discussed and guidance is provided.

  19. Prevention of ICU delirium and delirium-related outcome with haloperidol: a study protocol for a multicenter randomized controlled trial

    PubMed Central

    2013-01-01

    Background Delirium is a frequent disorder in intensive care unit (ICU) patients with serious consequences. Therefore, preventive treatment for delirium may be beneficial. Worldwide, haloperidol is the first choice for pharmacological treatment of delirious patients. In daily clinical practice, a lower dose is sometimes used as prophylaxis. Some studies have shown the beneficial effects of prophylactic haloperidol on delirium incidence as well as on mortality, but evidence for effectiveness in ICU patients is limited. The primary objective of our study is to determine the effect of haloperidol prophylaxis on 28-day survival. Secondary objectives include the incidence of delirium and delirium-related outcome and the side effects of haloperidol prophylaxis. Methods This will be a multicenter three-armed randomized, double-blind, placebo-controlled, prophylactic intervention study in critically ill patients. We will include consecutive non-neurological ICU patients, aged ≥18 years with an expected ICU length of stay >1 day. To be able to demonstrate a 15% increase in 28-day survival time with a power of 80% and alpha of 0.05 in both intervention groups, a total of 2,145 patients will be randomized; 715 in each group. The anticipated mortality rate in the placebo group is 12%. The intervention groups will receive prophylactic treatment with intravenous haloperidol 1 mg/q8h or 2 mg/q8h, and patients in the control group will receive placebo (sodium chloride 0.9%), both for a maximum period of 28-days. In patients who develop delirium, study medication will be stopped and patients will subsequently receive open label treatment with a higher (therapeutic) dose of haloperidol. We will use descriptive summary statistics as well as Cox proportional hazard regression analyses, adjusted for covariates. Discussion This will be the first large-scale multicenter randomized controlled prevention study with haloperidol in ICU patients with a high risk of delirium, adequately powered to demonstrate an effect on 28-day survival. Trial registration Clinicaltrials.gov: NCT01785290. EudraCT number: 2012-004012-66. PMID:24261644

  20. Options for Affordable Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

    2006-01-01

    Fission surface power systems could provide abundant power anywhere on free surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized; however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems.

  1. Developing a Resilient Green Cellular Network

    DTIC Science & Technology

    2013-12-01

    to provide BS autonomy from grid power through alternative energy, such as: fuel cells and xiii renewable photovoltaic (PV), wind energy...stations with adequate backup power or utilizing alternative/renewable energy technology such as photovoltaic or wind power to allow them to...mitigating strategies with the consensus view on BSs migrating away from grid power , to renewable energy ( photovoltaic ), and alternative fuels. 40

  2. 46 CFR 169.672 - Wiring for power and lighting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Wiring for power and lighting circuits must have copper conductors, of 14 AWG or larger, and— (1) Meet... must have stranded conductors. (c) Conductors must be sized so that— (1) They are adequate for the...

  3. Cognitive-behavioral therapy vs. light therapy for preventing winter depression recurrence: study protocol for a randomized controlled trial.

    PubMed

    Rohan, Kelly J; Evans, Maggie; Mahon, Jennifer N; Sitnikov, Lilya; Ho, Sheau-Yan; Nillni, Yael I; Postolache, Teodor T; Vacek, Pamela M

    2013-03-21

    Seasonal affective disorder (SAD) is a subtype of recurrent depression involving major depressive episodes during the fall and/or winter months that remit in the spring. The central public health challenge in the management of SAD is prevention of winter depression recurrence. Light therapy (LT) is the established and best available acute SAD treatment. However, long-term compliance with daily LT from first symptom through spontaneous springtime remission every fall/winter season is poor. Time-limited alternative treatments with effects that endure beyond the cessation of acute treatment are needed to prevent the annual recurrence of SAD. This is an NIMH-funded R01-level randomized clinical trial to test the efficacy of a novel, SAD-tailored cognitive-behavioral group therapy (CBT) against LT in a head-to-head comparison on next winter outcomes. This project is designed to test for a clinically meaningful difference between CBT and LT on depression recurrence in the next winter (the primary outcome). This is a concurrent two-arm study that will randomize 160 currently symptomatic community adults with major depression, recurrent with seasonal pattern, to CBT or LT. After 6 weeks of treatment in the initial winter, participants are followed in the subsequent summer, the next winter, and two winters later. Key methodological issues surround timing study procedures for a predictably recurrent and time-limited disorder with a focus on long-term outcomes. The chosen design answers the primary question of whether prior exposure to CBT is associated with a substantially lower likelihood of depression recurrence the next winter than LT. This design does not test the relative contributions of the cognitive-behavioral treatment components vs. nonspecific factors to CBT's outcomes and is not adequately powered to test for differences or equivalence between cells at treatment endpoint. Alternative designs addressing these limitations would have required more patients, increased costs, and reduced power to detect a difference in the primary outcome. Clinicaltrials.gov identifier NCT01714050.

  4. Under What Circumstances Does External Knowledge about the Correlation Structure Improve Power in Cluster Randomized Designs?

    ERIC Educational Resources Information Center

    Rhoads, Christopher

    2014-01-01

    Recent publications have drawn attention to the idea of utilizing prior information about the correlation structure to improve statistical power in cluster randomized experiments. Because power in cluster randomized designs is a function of many different parameters, it has been difficult for applied researchers to discern a simple rule explaining…

  5. Cannabinoids in treatment-resistant epilepsy: A review.

    PubMed

    O'Connell, Brooke K; Gloss, David; Devinsky, Orrin

    2017-05-01

    Treatment-resistant epilepsy (TRE) affects 30% of epilepsy patients and is associated with severe morbidity and increased mortality. Cannabis-based therapies have been used to treat epilepsy for millennia, but only in the last few years have we begun to collect data from adequately powered placebo-controlled, randomized trials (RCTs) with cannabidiol (CBD), a cannabis derivative. Previously, information was limited to case reports, small series, and surveys reporting on the use of CBD and diverse medical marijuana (MMJ) preparations containing: tetrahydrocannabinol (THC), CBD, and many other cannabinoids in differing combinations. These RCTs have studied the safety and explored the potential efficacy of CBD use in children with Dravet Syndrome (DS) and Lennox-Gastaut Syndrome (LGS). The role of the placebo response is of paramount importance in studying medical cannabis products given the intense social and traditional media attention, as well as the strong beliefs held by many parents and patients that a natural product is safer and more effective than FDA-approved pharmaceutical agents. We lack valid data on the safety, efficacy, and dosing of artisanal preparations available from dispensaries in the 25 states and District of Columbia with MMJ programs and online sources of CBD and other cannabinoids. On the other hand, open-label studies with 100mg/ml CBD (Epidiolex®, GW Pharmaceuticals) have provided additional evidence of its efficacy along with an adequate safety profile (including certain drug interactions) in children and young adults with a spectrum of TREs. Further, Phase 3 RCTs with Epidiolex support efficacy and adequate safety profiles for children with DS and LGS at doses of 10- and 20-mg/kg/day. This article is part of a Special Issue titled "Cannabinoids and Epilepsy". Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Critical Assessment of the Foundations of Power Transmission and Distribution Reliability Metrics and Standards.

    PubMed

    Nateghi, Roshanak; Guikema, Seth D; Wu, Yue Grace; Bruss, C Bayan

    2016-01-01

    The U.S. federal government regulates the reliability of bulk power systems, while the reliability of power distribution systems is regulated at a state level. In this article, we review the history of regulating electric service reliability and study the existing reliability metrics, indices, and standards for power transmission and distribution networks. We assess the foundations of the reliability standards and metrics, discuss how they are applied to outages caused by large exogenous disturbances such as natural disasters, and investigate whether the standards adequately internalize the impacts of these events. Our reflections shed light on how existing standards conceptualize reliability, question the basis for treating large-scale hazard-induced outages differently from normal daily outages, and discuss whether this conceptualization maps well onto customer expectations. We show that the risk indices for transmission systems used in regulating power system reliability do not adequately capture the risks that transmission systems are prone to, particularly when it comes to low-probability high-impact events. We also point out several shortcomings associated with the way in which regulators require utilities to calculate and report distribution system reliability indices. We offer several recommendations for improving the conceptualization of reliability metrics and standards. We conclude that while the approaches taken in reliability standards have made considerable advances in enhancing the reliability of power systems and may be logical from a utility perspective during normal operation, existing standards do not provide a sufficient incentive structure for the utilities to adequately ensure high levels of reliability for end-users, particularly during large-scale events. © 2015 Society for Risk Analysis.

  7. 75 FR 13142 - Florida Power and Light Company; Turkey Point, Units 3 and 4; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... Light Company; Turkey Point, Units 3 and 4; Exemption 1.0 Background Florida Power and Light Company... ferritic materials of pressure-retaining components of the reactor coolant pressure boundary of light water... reactor coolant pressure boundary of light water nuclear power reactors to provide adequate margins of...

  8. 30 CFR 57.12008 - Insulation and fittings for power wires and cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...

  9. 30 CFR 57.12008 - Insulation and fittings for power wires and cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...

  10. 30 CFR 57.12008 - Insulation and fittings for power wires and cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cables. Power wires and cables shall be insulated adequately where they pass into or out of electrical... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Insulation and fittings for power wires and cables. 57.12008 Section 57.12008 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF...

  11. 26 CFR 20.2038-1 - Revocable transfers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... subject at the date of the decedent's death to any change through the exercise of a power by the decedent to alter, amend, revoke, or terminate, or if the decedent relinquished such a power in contemplation... adequate and full consideration in money or money's worth (see § 20.2043-1); (2) If the decedent's power...

  12. 46 CFR 56.50-55 - Bilge pumps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Each self-propelled vessel must be provided with a power-driven pump or pumps connected to the bilge... power-driven pump is required. (See Part 171 of this chapter for determination of criterion numeral.) 5... available, or where a suitable water supply is available from a power-driven pump of adequate pressure and...

  13. Is ginger effective for the treatment of irritable bowel syndrome? A double blind randomized controlled pilot trial.

    PubMed

    van Tilburg, Miranda A L; Palsson, Olafur S; Ringel, Yehuda; Whitehead, William E

    2014-02-01

    Ginger is one of the most commonly used herbal medicines for irritable bowel syndrome (IBS) but no data exists about its effectiveness. Double blind randomized controlled trial. University of North Carolina, Chapel Hill, North Carolina, USA. Forty-five IBS patients were randomly assigned to three groups: placebo, 1g of ginger, and 2g of ginger daily for 28 days. The IBS severity scale (IBS-SS) was administered, as well as adequate relief of symptoms scale. A responder was defined as having at least 25% reduction in IBS-SS post-treatment. There were 57.1% responders to placebo, 46.7% to 1g and 33.3% to 2g of ginger. Adequate relief was reported by 53.3% on placebo and 53.3% in both ginger groups combined. Side effects were mild and reported by 35.7% in the placebo and 16.7% in the ginger groups. This double blind randomized controlled pilot study suggests ginger is well tolerated but did not perform better than placebo. Larger trials are needed before any definitive conclusions can be drawn. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Model-Based Diagnosis in a Power Distribution Test-Bed

    NASA Technical Reports Server (NTRS)

    Scarl, E.; McCall, K.

    1998-01-01

    The Rodon model-based diagnosis shell was applied to a breadboard test-bed, modeling an automated power distribution system. The constraint-based modeling paradigm and diagnostic algorithm were found to adequately represent the selected set of test scenarios.

  15. A Mixed-Methods, Randomized, Controlled Feasibility Trial to Inform the Design of a Phase III Trial to Test the Effect of the Handheld Fan on Physical Activity and Carer Anxiety in Patients With Refractory Breathlessness.

    PubMed

    Johnson, Miriam J; Booth, Sara; Currow, David C; Lam, Lawrence T; Phillips, Jane L

    2016-05-01

    The handheld fan is an inexpensive and safe way to provide facial airflow, which may reduce the sensation of chronic refractory breathlessness, a frequently encountered symptom. To test the feasibility of developing an adequately powered, multicenter, multinational randomized controlled trial comparing the efficacy of a handheld fan and exercise advice with advice alone in increasing activity in people with chronic refractory breathlessness from a variety of medical conditions, measuring recruitment rates; data quality; and potential primary outcome measures. This was a Phase II, multisite, international, parallel, nonblinded, mixed-methods randomized controlled trial. Participants were centrally randomized to fan or control. All received breathlessness self-management/exercise advice and were followed up weekly for four weeks. Participants/carers were invited to participate in a semistructured interview at the study's conclusion. Ninety-seven people were screened, 49 randomized (mean age 68 years; 49% men), and 43 completed the study. Site recruitment varied from 0.25 to 3.3/month and screening:randomization from 1.1:1 to 8.5:1. There were few missing data except for the Chronic Obstructive Pulmonary Disease Self-Efficacy Scale (two-thirds of data missing). No harms were observed. Three interview themes included 1) a fan is a helpful self-management strategy, 2) a fan aids recovery, and 3) a symptom control trial was welcome. A definitive, multisite trial to study the use of the handheld fan as part of self-management of chronic refractory breathlessness is feasible. Participants found the fan useful. However, the value of information for changing practice or policy is unlikely to justify the expense of such a trial, given perceived benefits, the minimal costs, and an absence of harms demonstrated in this study. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  16. Reactive Power Pricing Model Considering the Randomness of Wind Power Output

    NASA Astrophysics Data System (ADS)

    Dai, Zhong; Wu, Zhou

    2018-01-01

    With the increase of wind power capacity integrated into grid, the influence of the randomness of wind power output on the reactive power distribution of grid is gradually highlighted. Meanwhile, the power market reform puts forward higher requirements for reasonable pricing of reactive power service. Based on it, the article combined the optimal power flow model considering wind power randomness with integrated cost allocation method to price reactive power. Meanwhile, considering the advantages and disadvantages of the present cost allocation method and marginal cost pricing, an integrated cost allocation method based on optimal power flow tracing is proposed. The model realized the optimal power flow distribution of reactive power with the minimal integrated cost and wind power integration, under the premise of guaranteeing the balance of reactive power pricing. Finally, through the analysis of multi-scenario calculation examples and the stochastic simulation of wind power outputs, the article compared the results of the model pricing and the marginal cost pricing, which proved that the model is accurate and effective.

  17. Understanding Statistical Power in Cluster Randomized Trials: Challenges Posed by Differences in Notation and Terminology

    ERIC Educational Resources Information Center

    Spybrook, Jessaca; Hedges, Larry; Borenstein, Michael

    2014-01-01

    Research designs in which clusters are the unit of randomization are quite common in the social sciences. Given the multilevel nature of these studies, the power analyses for these studies are more complex than in a simple individually randomized trial. Tools are now available to help researchers conduct power analyses for cluster randomized…

  18. Randomized controlled trial of parent-enhanced CBT compared with individual CBT for obsessive-compulsive disorder in young people.

    PubMed

    Reynolds, Shirley A; Clark, Sarah; Smith, Holly; Langdon, Peter E; Payne, Ruth; Bowers, Gemma; Norton, Elisabeth; McIlwham, Harriet

    2013-12-01

    Obsessive-compulsive disorder (OCD) in young people can be effectively treated with Cognitive Behavior Therapy (CBT). Practice guidelines in the United Kingdom recommend that CBT be delivered with parental or family involvement; however, there is no evidence from randomized trials that this enhances effectiveness. The aim of this trial was to assess if CBT with high parental involvement was more effective than CBT with low parental involvement (individual CBT) in reducing symptoms of OCD. Fifty young people ages 12-17 years with OCD were randomly allocated to individual CBT or parent-enhanced CBT. In parent-enhanced CBT parents attended all treatment sessions; in individual CBT, parents attended only Sessions 1, 7, and the final session. Participants received up to 14 sessions of CBT. Data were analyzed using intent-to-treat and per-protocol methods. The primary outcome measure was the Children's Yale-Brown Obsessive Compulsion Scale (Scahill et al., 1997). Both forms of CBT significantly reduced symptoms of OCD and anxiety. Change in OCD symptoms was maintained at 6 months. Per-protocol analysis suggested that parent-enhanced CBT may be associated with significantly larger reductions in anxiety symptoms. High and low parental involvement in CBT for OCD in young people were both effective, and there was no evidence that 1 method of delivery was superior on the primary outcome measure. However, this study was small. Future trials should be adequately powered and examine interactions with the age of the young person and comorbid anxiety disorders.

  19. Interventions for the treatment of craniopharyngioma-related hypothalamic obesity: a systematic review.

    PubMed

    Ni, Weimin; Shi, Xiang'en

    2018-06-23

    Craniopharyngiomas (CPs) and their treatment are associated with hypothalamic damage that causes hypothalamic obesity (HO) in 30-70% of cases. Thus, there is ongoing research regarding tangible solutions for HO, as these patients have unrelenting resistance to basic weight-loss interventions. This review aims to summarize the interventions that are currently used to treat CP-related HO (CP-HO), including pharmacotherapy and bariatric surgery. The Cochrane Library, EMBASE, and PubMed databases were searched up to June 2017 for relevant reports. Two reviewers conducted independent evaluations of the identified studies. Eighteen publications were included in the systematic review, with three reports describing pharmacotherapy in randomized controlled trials and 15 reports describing bariatric surgery. Although several studies described effective interventions for treating CP-HO, the evidence base was limited by its low quality and our inability to perform a meta-analysis, which was related to a lack of adequate or integrated data. Octreotide appears to be a preferred treatment for CP-HO patients, based on currently limited data. Gastric bypass surgery may also be suitable for select CP-HO patients, based on a review of various procedures in this setting. Microsurgical preservation of the hypothalamic structures is mandatory to decrease CP-HO-related morbidity and mortality. Further studies with adequate analytical power and sufficient follow-up are needed to identify effective strategies for CP-HO treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Recommended high-tank temperatures for maintenance of high-tank backup support, Revision 3

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Greager, O.H.

    1964-05-20

    Purpose of this note is to recommend revised curves for the high-tank temperature required to maintain adequate high-tank backup support at the six small reactors. Compliance with the conditions shown on these curves will ensure adequate high-tank flow rates following the simultaneous loss of electric and steam power.

  1. Evaluation of a newly developed infant chest compression technique: A randomized crossover manikin trial.

    PubMed

    Smereka, Jacek; Bielski, Karol; Ladny, Jerzy R; Ruetzler, Kurt; Szarpak, Lukasz

    2017-04-01

    Providing adequate chest compression is essential during infant cardio-pulmonary-resuscitation (CPR) but was reported to be performed poor. The "new 2-thumb technique" (nTTT), which consists in using 2 thumbs directed at the angle of 90° to the chest while closing the fingers of both hands in a fist, was recently introduced. Therefore, the aim of this study was to compare 3 chest compression techniques, namely, the 2-finger-technique (TFT), the 2-thumb-technique (TTHT), and the nTTT in an randomized infant-CPR manikin setting. A total of 73 paramedics with at least 1 year of clinical experience performed 3 CPR settings with a chest compression:ventilation ratio of 15:2, according to current guidelines. Chest compression was performed with 1 out of the 3 chest compression techniques in a randomized sequence. Chest compression rate and depth, chest decompression, and adequate ventilation after chest compression served as outcome parameters. The chest compression depth was 29 (IQR, 28-29) mm in the TFT group, 42 (40-43) mm in the TTHT group, and 40 (39-40) mm in the nTTT group (TFT vs TTHT, P < 0.001; TFT vs nTTT, P < 0.001; TTHT vs nTTT, P < 0.01). The median compression rate with TFT, TTHT, and nTTT varied and amounted to 136 (IQR, 133-144) min versus 117 (115-121) min versus 111 (109-113) min. There was a statistically significant difference in the compression rate between TFT and TTHT (P < 0.001), TFT and nTTT (P < 0.001), as well as TTHT and nTTT (P < 0.001). Incorrect decompressions after CC were significantly increased in the TTHT group compared with the TFT (P < 0.001) and the nTTT (P < 0.001) group. The nTTT provides adequate chest compression depth and rate and was associated with adequate chest decompression and possibility to adequately ventilate the infant manikin. Further clinical studies are necessary to confirm these initial findings.

  2. The provision of therapy mattresses for pressure ulcer prevention.

    PubMed

    Pagnamenta, Fania

    2017-03-23

    Preventing pressure ulcers is complex and involves skin care, the provision of therapy mattresses, repositioning, the management of incontinence and adequate nutritional support. This article describes a model of therapy mattress provision that is based on non-powered products. Evaluating the efficiency of this model is challenging, due to the complexities of care, but Safety Thermometer data and incidents reports offer reassurance that non-powered therapy mattresses can provide adequate pressure ulcer prevention. Therapy mattress provision is only one of the five interventions and these are described in details to give readers a fuller picture of the model used at the author's trust.

  3. Hundred-watt-level high power random distributed feedback Raman fiber laser at 1150 nm and its application in mid-infrared laser generation.

    PubMed

    Zhang, Hanwei; Zhou, Pu; Wang, Xiong; Du, Xueyuan; Xiao, Hu; Xu, Xiaojun

    2015-06-29

    Two kinds of hundred-watt-level random distributed feedback Raman fiber have been demonstrated. The optical efficiency can reach to as high as 84.8%. The reported power and efficiency of the random laser is the highest one as we know. We have also demonstrated that the developed random laser can be further used to pump a Ho-doped fiber laser for mid-infrared laser generation. Finally, 23 W 2050 nm laser is achieved. The presented laser can obtain high power output efficiently and conveniently and opens a new direction for high power laser sources at designed wavelength.

  4. Work-Related CBT versus Vocational Services As Usual for Unemployed Persons with Social Anxiety Disorder: A Randomized Controlled Pilot Trial

    PubMed Central

    Himle, Joseph A.; Bybee, Deborah; Steinberger, Edward; Laviolette, Wayne T.; Weaver, Addie; Vlnka, Sarah; Golenberg, Zipora; Levine, Debra Siegel; Heimberg, Richard G.; O’Donnell, Lisa A.

    2014-01-01

    We designed and pilot-tested a group-based, work-related cognitive-behavioral therapy (WCBT) for unemployed individuals with social anxiety disorder (SAD). WCBT, delivered in a vocational service setting by vocational service professionals, aims to reduce social anxiety and enable individuals to seek, obtain, and retain employment. We compared WCBT to a vocational services as usual control condition (VSAU). Participants were unemployed, homeless, largely African American, vocational service-seeking adults with SAD (N=58), randomized to receive either eight sessions of WCBT plus VSAU or VSAU alone and followed three months post-treatment. Multilevel modeling revealed significantly greater reductions in social anxiety, general anxiety, depression, and functional impairment for WCBT compared to VSAU. Coefficients for job search activity and self-efficacy indicated greater increases for WCBT. Hours worked per week in the follow-up period did not differ between the groups, but small sample size and challenges associated with measuring work hours may have contributed to this finding. Overall, the results of this study suggest that unemployed persons with SAD can be effectively treated with specialized work-related CBT administered by vocational service professionals. Future testing of WCBT with a larger sample, a longer follow-up period, and adequate power to assess employment outcomes is warranted. PMID:25461793

  5. A non-equilibrium neutral model for analysing cultural change.

    PubMed

    Kandler, Anne; Shennan, Stephen

    2013-08-07

    Neutral evolution is a frequently used model to analyse changes in frequencies of cultural variants over time. Variants are chosen to be copied according to their relative frequency and new variants are introduced by a process of random mutation. Here we present a non-equilibrium neutral model which accounts for temporally varying population sizes and mutation rates and makes it possible to analyse the cultural system under consideration at any point in time. This framework gives an indication whether observed changes in the frequency distributions of a set of cultural variants between two time points are consistent with the random copying hypothesis. We find that the likelihood of the existence of the observed assemblage at the end of the considered time period (expressed by the probability of the observed number of cultural variants present in the population during the whole period under neutral evolution) is a powerful indicator of departures from neutrality. Further, we study the effects of frequency-dependent selection on the evolutionary trajectories and present a case study of change in the decoration of pottery in early Neolithic Central Europe. Based on the framework developed we show that neutral evolution is not an adequate description of the observed changes in frequency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Male Infertility during Antihypertensive Therapy: Are We Addressing Correctly The Problem?

    PubMed

    Laganà, Antonio Simone; Vitale, Salvatore Giovanni; Iaconianni, Paola; Gatti, Simona; Padula, Francesco

    2016-01-01

    Male fertility significantly decreased in the last 50 years, as showed in several studies reporting a reduction of sperm counts per ml in the seminal fluid. Several "acute" pharmacological treatments, as antibiotics, could cause subclinical and temporary reduction of male fertility; conversely, long-term medical treatment may severely affect male fertility, although this effect could be considered transient in most of the cases. Thus, nowadays, several long-term pharmacological treatments may represent a clinical challenge. The association between several kind of antihypertensive drugs and reduction of male fertility has been showed in the mouse model, although the modification(s) which may alter this fine-regulated machinery are still far to be elucidated. Furthermore, well-designed observational studies and randomized controlled trials are needed to accurately define this association in human model, meaning a narrative overview synthesizing the findings of literature retrieved from searches of computerized databases. We strongly solicit future human studies (both observational and randomized clinical trials) on large cohorts with adequate statistical power which may clarify this possible association and the effects (reversible or permanent) of each drug. Furthermore, we suggest a close collaboration between general practitioners, cardiologists, and andrologists in order to choose the most appropriate antihypertensive therapy considering also patient's reproductive desire and possible risk for his fertility.

  7. Results of a faith-based weight loss intervention for black women.

    PubMed

    Fitzgibbon, Marian L; Stolley, Melinda R; Ganschow, Pamela; Schiffer, Linda; Wells, Anita; Simon, Nolanna; Dyer, Alan

    2005-10-01

    Obesity is a risk factor for a variety of chronic diseases. Although weight loss may reduce these risks, weight loss programs designed for black women have yielded mixed results. Studies suggest that religion/spirituality is a prominent component of black culture. Given this, the inclusion of religion/spirituality as an active component of a weight loss program may enhance the benefits of the program. The role of religion/spirituality, however, has not been specifically tested as a mechanism that enhances the weight loss process. This paper presents the results of "Faith on the Move," a randomized pilot study of a faith-based weight loss program for black women. The goals of the study were to estimate the effects of a 12-week culturally tailored, faith-based weight loss intervention on weight loss, dietary fat consumption and physical activity. The culturally tailored, faith-based weight loss intervention was compared to a culturally tailored weight loss intervention with no active faith component. Fifty-nine overweight/obese black women were randomized to one of the two interventions. Although the results were not statistically significant, the effect size suggests that the addition of the faith component improved results. These promising preliminary results will need to be tested in an adequately powered trial.

  8. A systematic review of SNAPO (Smoking, Nutrition, Alcohol, Physical activity and Obesity) randomized controlled trials in young adult men.

    PubMed

    Ashton, Lee M; Morgan, Philip J; Hutchesson, Melinda J; Rollo, Megan E; Young, Myles D; Collins, Clare E

    2015-12-01

    To investigate the effectiveness of Smoking, Nutrition, Alcohol, Physical activity and Obesity (SNAPO) interventions in young men exclusively. The secondary aim was to evaluate the recruitment, retention and engagement strategies. A search with no date restrictions was conducted across seven databases. Randomized controlled trials recruiting young men only (aged 18-35 years) into interventions targeting any SNAPO risk factors were included. Ten studies were included (two nutrition, six alcohol use, two targeting multiple SNAPO risk factors). Six studies (two nutrition, three alcohol use and one targeting multiple SNAPO risk factors) demonstrated significant positive short-term intervention effects, but impact was either not assessed beyond the intervention (n=3), had short-term follow-up (≤6 months) (n=2) or not sustained beyond six months (n=1). Overall, a high risk of bias was identified across studies. Only one study undertook a power calculation and recruited the required sample size. Adequate retention was achieved in three studies. Effectiveness of engagement strategies was not reported in any studies. Despite preliminary evidence of short-term effectiveness of SNAPO interventions in young men, few studies characterized by a high risk of bias were identified. High quality SNAPO interventions for young men are warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Hypertonic dextrose injections (prolotherapy) in the treatment of symptomatic knee osteoarthritis: A systematic review and meta-analysis

    PubMed Central

    Sit, Regina WS; Chung, Vincent CH; Reeves, Kenneth D.; Rabago, David; Chan, Keith KW; Chan, Dicken CC; Wu, Xinyin; Ho, Robin ST; Wong, Samuel YS

    2016-01-01

    Hypertonic dextrose injections (prolotherapy) is an emerging treatment for symptomatic knee osteoarthritis (OA) but its efficacy is uncertain. We conducted a systematic review with meta-analysis to synthesize clinical evidence on the effect of prolotherapy for knee OA. Fifteen electronic databases were searched from their inception to September 2015. The primary outcome of interest was score change on the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Three randomized controlled trials (RCTs) of moderate risk of bias and one quasi–randomized trial were included, with data from a total of 258 patients. In the meta-analysis of two eligible studies, prolotherapy is superior to exercise alone by a standardized mean difference (SMD) of 0.81 (95% CI: 0.18 to 1.45, p = 0.012), 0.78 (95% CI: 0.25 to 1.30, p = 0.001) and 0.62 (95% CI: 0.04 to 1.20, p = 0.035) on the WOMAC composite scale; and WOMAC function and pain subscale scores respectively. Moderate heterogeneity exists in all cases. Overall, prolotherapy conferred a positive and significant beneficial effect in the treatment of knee OA. Adequately powered, longer-term trials with uniform end points are needed to better elucidate the efficacy of prolotherapy. PMID:27146849

  10. Using the MEDiPORT humanoid robot to reduce procedural pain and distress in children with cancer: A pilot randomized controlled trial.

    PubMed

    Jibb, Lindsay A; Birnie, Kathryn A; Nathan, Paul C; Beran, Tanya N; Hum, Vanessa; Victor, J Charles; Stinson, Jennifer N

    2018-06-12

    Subcutaneous port needle insertions are painful and distressing for children with cancer. The interactive MEDiPORT robot has been programmed to implement psychological strategies to decrease pain and distress during this procedure. This study assessed the feasibility of a future MEDiPORT trial. The secondary aim was to determine the preliminary effectiveness of MEDiPORT in reducing child pain and distress during subcutaneous port accesses. This 5-month pilot randomized controlled trial used a web-based service to randomize 4- to 9-year-olds with cancer to the MEDiPORT cognitive-behavioral arm (robot using evidence-based cognitive-behavioral interventions) or active distraction arm (robot dancing and singing) while a nurse conducted a needle insertion. We assessed accrual and retention; technical difficulties; outcome measure completion by children, parents, and nurses; time taken to complete the study and clinical procedure; and child-, parent-, and nurse-rated acceptability. Descriptive analyses, with exploratory inferential testing of child pain and distress data, were used to address study aims. Forty children were randomized across study arms. Most (85%) eligible children participated and no children withdrew. Technical difficulties were more common in the cognitive-behavioral arm. Completion times for the study and needle insertion were acceptable and >96% of outcome measure items were completed. Overall, MEDiPORT and the study were acceptable to participants. There was no difference in pain between arms, but distress during the procedure was less pronounced in the active distraction arm. The MEDiPORT study appears feasible to implement as an adequately-powered effectiveness-assessing trial following modifications to the intervention and study protocol. ClinicalTrials.gov NCT02611739. © 2018 Wiley Periodicals, Inc.

  11. Group interventions for co-morbid insomnia and osteoarthritis pain in primary care: the lifestyles cluster randomized trial design.

    PubMed

    Von Korff, Michael; Vitiello, Michael V; McCurry, Susan M; Balderson, Benjamin H; Moore, Amy L; Baker, Laura D; Yarbro, Patricia; Saunders, Kathleen; Keefe, Francis J; Rybarczyk, Bruce D

    2012-07-01

    Six weekly sessions of group cognitive-behavioral therapy for insomnia and osteoarthritis pain (CBT-PI), and for osteoarthritis pain alone (CBT-P) were compared to an education only control (EOC). Basic education about pain and sleep was comparable, so EOC controlled for information and group participation. Active interventions differed from EOC in training pain coping skills (CBT-P and CBT-PI) and sleep enhancement techniques (CBT-PI). Persons with osteoarthritis age 60 or older were screened for osteoarthritis pain and insomnia severity via mailed survey. Primary outcomes were pain severity (pain intensity and interference ratings from the Graded Chronic Pain Scale) and insomnia severity (Insomnia Severity Index). Secondary outcomes were arthritis pain (AIMS-2 symptom scale) and sleep efficiency assessed by wrist actigraphy. Ancillary outcomes included: cognitive function, depression, and health care use. A clustered randomized design provided adequate power to identify moderate effects on primary outcomes (effect size>0.35). Modified intent to treat analyses, including all participants who attended the first session, assessed effects across CBT-PI, CBT-P, and EOC groups. Treatment effects were assessed post-intervention (2 months) and at 9 months, with durability of intervention effects evaluated at 18 months. The trial was executed in 6 primary clinics, randomizing 367 participants, with 93.2% of randomized patients attending at least 4 group sessions. Response rates for post-intervention and 9 month assessments were 96.7% and 92.9% respectively. This hybrid efficacy-effectiveness trial design evaluates whether interventions yield specific benefits for clinical and behavioral outcomes relative to an education only control when implemented in a primary care setting. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Dynamic analysis of a pumped-storage hydropower plant with random power load

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Chen, Diyi; Xu, Beibei; Patelli, Edoardo; Tolo, Silvia

    2018-02-01

    This paper analyzes the dynamic response of a pumped-storage hydropower plant in generating mode. Considering the elastic water column effects in the penstock, a linearized reduced order dynamic model of the pumped-storage hydropower plant is used in this paper. As the power load is always random, a set of random generator electric power output is introduced to research the dynamic behaviors of the pumped-storage hydropower plant. Then, the influences of the PI gains on the dynamic characteristics of the pumped-storage hydropower plant with the random power load are analyzed. In addition, the effects of initial power load and PI parameters on the stability of the pumped-storage hydropower plant are studied in depth. All of the above results will provide theoretical guidance for the study and analysis of the pumped-storage hydropower plant.

  13. Focusing of high intensity ultrasound through the rib cage using a therapeutic random phased array

    PubMed Central

    Bobkova, Svetlana; Gavrilov, Leonid; Khokhlova, Vera; Shaw, Adam; Hand, Jeffrey; #, ||

    2010-01-01

    A method for focusing high intensity ultrasound through a rib cage that aims to minimize heating of the ribs whilst maintaining high intensities at the focus (or foci) is proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, are investigated theoretically for idealized source conditions. It is shown that for an idealized radiator the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% versus 7.5% of the irradiated power) compared with the geometric one. A 2D 1-MHz phased array with 254 randomly distributed elements, tissue mimicking phantoms, and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infra-red camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at ± 10–15 mm off and ± 20 mm along the array axis. Focus splitting due to the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU for which the rib cage lies between the transducer(s) and the targeted tissue. PMID:20510186

  14. Challenges of Obtaining Evidence-Based Information Regarding Medications and Male Fertility.

    PubMed

    Drobnis, Erma Z; Nangia, Ajay K

    2017-01-01

    In the clinic, the existing literature is insufficient to counsel our infertile men on medication use. Most studies have flaws that limit their application to evidence-based practice. In this chapter, we discuss the limitations of the current literature and the challenges to designing more useful studies. Among the most important weaknesses of existing studies is lack of power; that is, too few men are included to draw conclusions about the existence and size of medication effects. Adequate power is particularly important when confirming an absence of medication effect. Bias is also a problem in most studies. Early studies were rarely randomized, placebo-controlled, or blinded; a common example is patients receiving different medication regimes based on the severity of their symptoms-making it impossible to attribute differences between treated and untreated men to the medications. Additional bias is introduced by failing to include other factors that influence the outcome in the experimental design. A uniform population amenable to randomization and placebo-control are experimental species, and useful information has been gained from these models. However, application to humans is limited by differences from other species in route of drug administration, absorption of the drug, concentration in the male genital tract tissues, and genital tract physiology. To a lesser degree, there is variation among individual men in their response to drugs. In addition, drugs in the same class may have different effects, limiting the applicability of data across drugs of a single class. Complicating matters further, a toxic medication may seem to improve fertility endpoints by improving a disease condition that diminishes fertility. Finally, drug interactions have not been studied, and actual fertility data (pregnancy/fecundity) in humans are rare. A healthy dose of skepticism is warranted when evaluating studies of medications and male reproductive health.

  15. Hemostatic Agents in Periapical Surgery: A Randomized Study of Gauze Impregnated in Epinephrine versus Aluminum Chloride.

    PubMed

    Menéndez-Nieto, Isabel; Cervera-Ballester, Juan; Maestre-Ferrín, Laura; Blaya-Tárraga, Juan Antonio; Peñarrocha-Oltra, David; Peñarrocha-Diago, Miguel

    2016-11-01

    Adequate bleeding control is essential for the success of periapical surgery. The aim of this study was to evaluate the effects of 2 hemostatic agents on the outcome of periapical surgery and their relationship with patient and teeth parameters. A prospective study was designed with 2 randomized parallel groups, depending on the hemostatic agent used: gauze impregnated in epinephrine (epinephrine group) and aluminum chloride (aluminum chloride group). The analysis of the hemorrhage control was judged before and after the application of the hemostatic agents by the surgeon, and 2 examiners independently recorded it as adequate (complete hemorrhage control) or inadequate (incomplete hemorrhage control). Ninety-nine patients with a periradicular lesion were enrolled in this study and divided into 2 groups: gauze impregnated in epinephrine in 48 patients (epinephrine group) or aluminum chloride in 51 (aluminum chloride group). In epinephrine group adequate hemostasis was achieved in 25 cases, and in aluminum chloride group it was achieved in 37 cases (P < .05). The outcome was better in the aluminum chloride group than in the gauze impregnated in epinephrine group. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Assessment of Registration Information on Methodological Design of Acupuncture RCTs: A Review of 453 Registration Records Retrieved from WHO International Clinical Trials Registry Platform

    PubMed Central

    Gu, Jing; Wang, Qi; Wang, Xiaogang; Li, Hailong; Gu, Mei; Ming, Haixia; Dong, Xiaoli; Yang, Kehu; Wu, Hongyan

    2014-01-01

    Background. This review provides the first methodological information assessment of protocol of acupuncture RCTs registered in WHO International Clinical Trials Registry Platform (ICTRP). Methods. All records of acupuncture RCTs registered in the ICTRP have been collected. The methodological design assessment involved whether the randomization methods, allocation concealment, and blinding were adequate or not based on the information of registration records (protocols of acupuncture RCTs). Results. A total of 453 records, found in 11 registries, were examined. Methodological details were insufficient in registration records; there were 76.4%, 89.0%, and 21.4% records that did not provide information on randomization methods, allocation concealment, and blinding respectively. The proportions of adequate randomization methods, allocation concealment, and blinding were only 107 (23.6%), 48 (10.6%), and 210 (46.4%), respectively. The methodological design improved year by year, especially after 2007. Additionally, methodology of RCTs with ethics approval was clearly superior to those without ethics approval and different among registries. Conclusions. The overall methodological design based on registration records of acupuncture RCTs is not very well but improved year by year. The insufficient information on randomization methods, allocation concealment, and blinding maybe due to the relevant description is not taken seriously in acupuncture RCTs' registration. PMID:24688591

  17. Assessment of Registration Information on Methodological Design of Acupuncture RCTs: A Review of 453 Registration Records Retrieved from WHO International Clinical Trials Registry Platform.

    PubMed

    Gu, Jing; Wang, Qi; Wang, Xiaogang; Li, Hailong; Gu, Mei; Ming, Haixia; Dong, Xiaoli; Yang, Kehu; Wu, Hongyan

    2014-01-01

    Background. This review provides the first methodological information assessment of protocol of acupuncture RCTs registered in WHO International Clinical Trials Registry Platform (ICTRP). Methods. All records of acupuncture RCTs registered in the ICTRP have been collected. The methodological design assessment involved whether the randomization methods, allocation concealment, and blinding were adequate or not based on the information of registration records (protocols of acupuncture RCTs). Results. A total of 453 records, found in 11 registries, were examined. Methodological details were insufficient in registration records; there were 76.4%, 89.0%, and 21.4% records that did not provide information on randomization methods, allocation concealment, and blinding respectively. The proportions of adequate randomization methods, allocation concealment, and blinding were only 107 (23.6%), 48 (10.6%), and 210 (46.4%), respectively. The methodological design improved year by year, especially after 2007. Additionally, methodology of RCTs with ethics approval was clearly superior to those without ethics approval and different among registries. Conclusions. The overall methodological design based on registration records of acupuncture RCTs is not very well but improved year by year. The insufficient information on randomization methods, allocation concealment, and blinding maybe due to the relevant description is not taken seriously in acupuncture RCTs' registration.

  18. The power to detect trends in Missouri River fish populations within the Pallid Sturgeon Population Assessment Program

    USGS Publications Warehouse

    Bryan, Janice L.; Wildhaber, Mark L.; Gladish, Dan; Holan, Scott; Ellerseick, Mark

    2010-01-01

    As with all large rivers in the United States, the Missouri River has been altered, with approximately 32.5 percent of the main stem length impounded and 32.5 percent channelized. These physical alterations to the environment have had effects on the fisheries, but studies examining the effects of alterations have been localized and for short periods of time. In response to the U.S. Fish and Wildlife Service biological opinion, the U.S. Army Corps of Engineers initiated monitoring of the fish community of the Missouri River in 2003. The goal of the Pallid Sturgeon Population Assessment Program is to provide information to detect changes in populations and habitat preferences with time for pallid sturgeon (Scaphirhynchus albus) and native target species in the Missouri River Basin. To determine statistical power of the Pallid Sturgeon Population Assessment Program, a power analysis was conducted using a normal linear mixed model with variance component estimates based on the first 3 years of data (2003 to 2005). In cases where 3 years of data were unavailable, estimates were obtained using those data. It was determined that at least 20 years of data, sampling 12 bends with 8 subsamples per bend, would be required to detect a 5 percent annual decline in most of the target fish populations. Power varied between Zones. Zone 1 (upstream from Lake Sakakawea) did not have any species/gear type combinations with adequate power, whereas Zone 3 (downstream from Gavins Point Dam) had 19 species/gear type combinations with adequate power. With a slight increase in the sampling effort to 12 subsamples per bend, the Pallid Sturgeon Population Assessment Program has adequate power to detect declines in shovelnose sturgeon (S. platorynchus) throughout the entire Missouri River because of large catch rates. The lowest level of non-occurrence (in other words, zero catches) at the bend level for pallid sturgeon was 0.58 using otter trawls in Zone 1. Consequently, the power of the pallid sturgeon models was not as high as other species at the current level of sampling, but an increase in the sampling effort to 16 subsamples for each of 24 bends for 20 years would generate adequate power for the pallid sturgeon in all Zones. Since gear types are selective in their species efficiency, the strength of the Pallid Sturgeon Population Assessment Program approach is using multiple gears that have statistical power to detect population trends at the same time in different fish species within the Missouri River. As often is the case with monitoring studies involving endangered species, the data used to conduct the analyses exhibit some departures from the parametric model assumptions; however, preliminary simulations indicate that the results of this study are appropriate.

  19. Procalcitonin, pyuria and proadrenomedullin in the management of urinary tract infections--'triple p in uti': study protocol for a randomized controlled trial.

    PubMed

    Drozdov, Daniel; Thomer, Anja; Meili, Marc; Schwarz, Stefanie; Kouegbe, Rita Bossart; Regez, Katharina; Guglielmetti, Merih; Schild, Ursula; Conca, Antoinette; Schäfer, Petra; Reutlinger, Barbara; Ottiger, Cornelia; Buchkremer, Florian; Litke, Alexander; Schuetz, Philipp; Huber, Andreas; Bürgi, Ulrich; Fux, Christoph A; Bock, Andreas; Müller, Beat; Albrich, Werner C

    2013-03-22

    Urinary tract infections (UTIs) are among the most common infectious diseases and drivers of antibiotic use and in-hospital days. A reduction of antibiotic use potentially lowers the risk of antibiotic resistance. An early and adequate risk assessment combining medical, biopsychosocial and functional risk scores has the potential to optimize site-of-care decisions and thus allocation of limited health-care resources. The aim of this factorial design study is twofold: first, for Intervention A, it investigates antibiotic exposure of patients treated with a protocol based on the type of UTI, procalcitonin (PCT) and pyuria. Second, for Intervention B, it investigates the usefulness of the prognostic biomarker proadrenomedullin (ProADM) integrated into an interdisciplinary assessment bundle for site-of-care decisions. This randomized controlled open-label trial has a factorial design (2 × 2). Randomization of patients will be based on a pre-specified computer-generated randomization list and independent for the two interventions. Adults with UTI presenting to the emergency department (ED) will be screened and enrolled after providing informed consent. For our first Intervention (A), we developed a protocol based on previous observational research to recommend initiation and duration of antibiotic use based on the clinical presentation of UTI, pyuria and PCT levels. For our second intervention (B), an algorithm was developed to support site-of care decisions based on the prognostic marker ProADM and distinct nursing factors on days 1 and 3. Both interventions will be compared with a control group conforming to the guidelines. The primary endpoints for the two interventions will be: (A) overall exposure to antibiotics and (B) length of physician-led hospitalization within a follow-up of 30 days. Endpoints are assessed at discharge from hospital, and 30 and 90 days after admission. We plan to screen 300 patients and enroll 250 for an anticipated estimated loss of follow-up of 20%. This will provide adequate power for the two interventions. This trial investigates two strategies for improved individualized medical care in patients with UTI. The minimally effective duration of antibiotic therapy is not known for UTIs, which is important for reducing the selection pressure for antibiotic resistance, costs and drug-related side effects. Triage decisions must be improved to reflect the true medical, biopsychosocial and functional risks in order to allocate patients to the most appropriate care setting and reduce hospital-acquired disability. ISRCTN13663741.

  20. High power tunable mid-infrared optical parametric oscillator enabled by random fiber laser.

    PubMed

    Wu, Hanshuo; Wang, Peng; Song, Jiaxin; Ye, Jun; Xu, Jiangming; Li, Xiao; Zhou, Pu

    2018-03-05

    Random fiber laser, as a kind of novel fiber laser that utilizes random distributed feedback as well as Raman gain, has become a research focus owing to its advantages of wavelength flexibility, modeless property and output stability. Herein, a tunable optical parametric oscillator (OPO) enabled by a random fiber laser is reported for the first time. By exploiting a tunable random fiber laser to pump the OPO, the central wavelength of idler light can be continuously tuned from 3977.34 to 4059.65 nm with stable temporal average output power. The maximal output power achieved is 2.07 W. So far as we know, this is the first demonstration of a continuous-wave tunable OPO pumped by a tunable random fiber laser, which could not only provide a new approach for achieving tunable mid-infrared (MIR) emission, but also extend the application scenarios of random fiber lasers.

  1. Video on Diet Before Outpatient Colonoscopy Does Not Improve Quality of Bowel Preparation: A Prospective, Randomized, Controlled Trial.

    PubMed

    Rice, Sean C; Higginbotham, Tina; Dean, Melanie J; Slaughter, James C; Yachimski, Patrick S; Obstein, Keith L

    2016-11-01

    Successful outpatient colonoscopy (CLS) depends on many factors including the quality of a patient's bowel preparation. Although education on consumption of the pre-CLS purgative can improve bowel preparation quality, no study has evaluated dietary education alone. We have created an educational video on pre-CLS dietary instructions to determine whether dietary education would improve outpatient bowel preparation quality. A prospective randomized, blinded, controlled study of patients undergoing outpatient CLS was performed. All patients received a 4 l polyethylene glycol-based split-dose bowel preparation and standard institutional pre-procedure instructions. Patients were then randomly assigned to an intervention arm or to a no intervention arm. A 4-min educational video detailing clear liquid diet restriction was made available to patients in the intervention arm, whereas those randomized to no intervention did not have access to the video. Patients randomized to the video were provided with the YouTube video link 48-72 h before CLS. An attending endoscopist blinded to randomization performed the CLS. Bowel preparation quality was scored using the Boston Bowel Preparation Scale (BBPS). Adequate preparation was defined as a BBPS total score of ≥6 with all segment scores ≥2. Wilcoxon rank-sum and Pearson's χ 2 -tests were performed to assess differences between groups. Ninety-two patients were randomized (video: n=42; control: n=50) with 47 total video views being tallied. There were no demographic differences between groups. There was no statistically significant difference in adequate preparation between groups (video=74%; control=68%; P=0.54). The availability of a supplementary patient educational video on clear liquid diet alone was insufficient to improve bowel preparation quality when compared with standard pre-procedure instruction at our institution.

  2. Branching random walk with step size coming from a power law

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Ayan; Subhra Hazra, Rajat; Roy, Parthanil

    2015-09-01

    In their seminal work, Brunet and Derrida made predictions on the random point configurations associated with branching random walks. We shall discuss the limiting behavior of such point configurations when the displacement random variables come from a power law. In particular, we establish that two prediction of remains valid in this setup and investigate various other issues mentioned in their paper.

  3. Data series embedding and scale invariant statistics.

    PubMed

    Michieli, I; Medved, B; Ristov, S

    2010-06-01

    Data sequences acquired from bio-systems such as human gait data, heart rate interbeat data, or DNA sequences exhibit complex dynamics that is frequently described by a long-memory or power-law decay of autocorrelation function. One way of characterizing that dynamics is through scale invariant statistics or "fractal-like" behavior. For quantifying scale invariant parameters of physiological signals several methods have been proposed. Among them the most common are detrended fluctuation analysis, sample mean variance analyses, power spectral density analysis, R/S analysis, and recently in the realm of the multifractal approach, wavelet analysis. In this paper it is demonstrated that embedding the time series data in the high-dimensional pseudo-phase space reveals scale invariant statistics in the simple fashion. The procedure is applied on different stride interval data sets from human gait measurements time series (Physio-Bank data library). Results show that introduced mapping adequately separates long-memory from random behavior. Smaller gait data sets were analyzed and scale-free trends for limited scale intervals were successfully detected. The method was verified on artificially produced time series with known scaling behavior and with the varying content of noise. The possibility for the method to falsely detect long-range dependence in the artificially generated short range dependence series was investigated. (c) 2009 Elsevier B.V. All rights reserved.

  4. Dark energy homogeneity in general relativity: Are we applying it correctly?

    NASA Astrophysics Data System (ADS)

    Duniya, Didam G. A.

    2016-04-01

    Thus far, there does not appear to be an agreed (or adequate) definition of homogeneous dark energy (DE). This paper seeks to define a valid, adequate homogeneity condition for DE. Firstly, it is shown that as long as w_x ≠ -1, DE must have perturbations. It is then argued, independent of w_x, that a correct definition of homogeneous DE is one whose density perturbation vanishes in comoving gauge: and hence, in the DE rest frame. Using phenomenological DE, the consequence of this approach is then investigated in the observed galaxy power spectrum—with the power spectrum being normalized on small scales, at the present epoch z=0. It is found that for high magnification bias, relativistic corrections in the galaxy power spectrum are able to distinguish the concordance model from both a homogeneous DE and a clustering DE—on super-horizon scales.

  5. Wordless intervention for epilepsy in learning disabilities (WIELD): study protocol for a randomized controlled feasibility trial.

    PubMed

    Durand, Marie-Anne; Gates, Bob; Parkes, Georgina; Zia, Asif; Friedli, Karin; Barton, Garry; Ring, Howard; Oostendorp, Linda; Wellsted, David

    2014-11-20

    Epilepsy is the most common neurological problem that affects people with learning disabilities. The high seizure frequency, resistance to treatments, associated skills deficit and co-morbidities make the management of epilepsy particularly challenging for people with learning disabilities. The Books Beyond Words booklet for epilepsy uses images to help people with learning disabilities manage their condition and improve quality of life. Our aim is to conduct a randomized controlled feasibility trial exploring key methodological, design and acceptability issues, in order to subsequently undertake a large-scale randomized controlled trial of the Books Beyond Words booklet for epilepsy. We will use a two-arm, single-centre randomized controlled feasibility design, over a 20-month period, across five epilepsy clinics in Hertfordshire, United Kingdom. We will recruit 40 eligible adults with learning disabilities and a confirmed diagnosis of epilepsy and will randomize them to use either the Books Beyond Words booklet plus usual care (intervention group) or to receive routine information and services (control group). We will collect quantitative data about the number of eligible participants, number of recruited participants, demographic data, discontinuation rates, variability of the primary outcome measure (quality of life: Epilepsy and Learning Disabilities Quality of Life scale), seizure severity, seizure control, intervention's patterns of use, use of other epilepsy-related information, resource use and the EQ-5D-5L health questionnaire. We will also gather qualitative data about the feasibility and acceptability of the study procedures and the Books Beyond Words booklet. Ethical approval for this study was granted on 28 April 2014, by the Wales Research Ethics Committee 5. Recruitment began on 1 July 2014. The outcomes of this feasibility study will be used to inform the design and methodology of a definitive study, adequately powered to determine the impact of the Books Beyond Words intervention to improve the management of epilepsy in people with learning disabilities. http://ISRCTN80067039 (Date of ISRCTN assignation: 23 April 2014).

  6. Mortality risk of darbepoetin alfa versus epoetin alfa in patients with CKD: systematic review and meta-analysis.

    PubMed

    Wilhelm-Leen, Emilee R; Winkelmayer, Wolfgang C

    2015-07-01

    Epoetin alfa (EPO) and darbepoetin alfa (DPO) are erythropoiesis-stimulating agents that are widely and interchangeably used for the treatment of anemia in patients with advanced chronic kidney disease and end-stage renal disease. No study has specifically compared the risks of hard study outcomes between EPO and DPO, including mortality. Systematic review of the literature and meta-analysis. Patients enrolled in randomized trials comparing EPO versus DPO for the treatment of anemia in adults with chronic kidney disease, including those requiring dialysis. We conducted a systematic search of the literature (PubMed, CENTRAL, SCOPUS, and EMBASE, all years) and industry resources, using predefined search terms and data abstraction tools. We then summarized key characteristics and findings of these trials and performed a random-effects meta-analysis of trials with at least 3 months' duration to identify the summary OR of mortality between patients randomly assigned to DPO versus EPO. DPO versus EPO. All-cause mortality. We identified 9 trials that met the stated inclusion criteria. Overall, 2,024 patients were included in the meta-analysis, of whom 126 died during follow-up, which ranged from 20 to 52 weeks. We found no significant difference in mortality between patients randomly assigned to DPO versus EPO (OR, 1.33; 95% CI, 0.88-2.01). No treatment heterogeneity across studies was detected (Q statistic=4.60; P=0.8). Generalizability to nontrial populations is uncertain. Few trials directly comparing DPO and EPO have been conducted and follow-up was limited. In aggregate, no effect of specific erythropoiesis-stimulating agent on mortality was identified, but the confidence limits were wide and remained compatible with considerable harm from DPO. Absent adequately powered randomized trials, observational postmarketing comparative effectiveness studies comparing these erythropoiesis-stimulating agents are required to better characterize the long-term safety profiles of these agents. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  7. Associations of government health expenditures, the supply of health care professionals, and country literacy with prenatal care use in ten West African countries.

    PubMed

    Taylor, Yhenneko J; Laditka, Sarah B; Laditka, James N; Brunner Huber, Larissa R; Racine, Elizabeth F

    2017-03-01

    Social and health care context may influence prenatal care use. We studied associations of government health expenditures, supply of health care professionals, and country literacy rates with prenatal care use in ten West African countries, controlling for individual factors. We used data from Demographic and Health Surveys (n = 58,512) and random effect logistic regression models to estimate the likelihood of having any prenatal care and adequate prenatal care. Each percentage increase in the literacy rate was associated with 4% higher odds of having adequate prenatal care (p = .029). Higher literacy rates among women may help to promote adequate prenatal care.

  8. 40 CFR 63.10897 - What are my monitoring requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...

  9. 40 CFR 63.10897 - What are my monitoring requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...

  10. 40 CFR 63.10897 - What are my monitoring requirements?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...

  11. 40 CFR 63.10897 - What are my monitoring requirements?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...

  12. 40 CFR 63.10897 - What are my monitoring requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... controls for corona power and rapper operation, that the corona wires are energized, and that adequate air... determine the condition and integrity of corona wires, collection plates, hopper, and air diffuser plates... daily inspection to verify the proper functioning of the electronic controls for corona power and rapper...

  13. Photovoltaic power systems workshop

    NASA Technical Reports Server (NTRS)

    Killian, H. J.; Given, R. W.

    1978-01-01

    Discussions are presented on apparent deficiencies in NASA planning and technology development relating to a standard power module (25-35 kW) and to future photovoltaic power systems in general. Topics of discussion consider the following: (1) adequate studies on power systems; (2) whether a standard power system module should be developed from a standard spacecraft; (3) identification of proper approaches to cost reduction; (4) energy storage avoidance; (5) attitude control; (6) thermal effects of heat rejection on solar array configuration stability; (7) assembly of large power systems in space; and (8) factoring terrestrial photovoltaic work into space power systems for possible payoff.

  14. Power and efficiency of insect flight muscle.

    PubMed

    Ellington, C P

    1985-03-01

    The efficiency and mechanical power output of insect flight muscle have been estimated from a study of hovering flight. The maximum power output, calculated from the muscle properties, is adequate for the aerodynamic power requirements. However, the power output is insufficient to oscillate the wing mass as well unless there is good elastic storage of the inertial energy, and this is consistent with reports of elastic components in the flight system. A comparison of the mechanical power output with the metabolic power input to the flight muscles suggests that the muscle efficiency is quite low: less than 10%.

  15. Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice

    PubMed Central

    Han, Changsu; Wang, Sheng-Min; Lee, Soo-Jung; Jun, Tae-Youn

    2015-01-01

    Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD. PMID:26306301

  16. Vegetation responses to natural regulation of elk in Rocky Mountain National Park

    USGS Publications Warehouse

    Zeigenfuss, Linda C.; Singer, Francis J.; Bowden, David

    1999-01-01

    Some grazing-induced responses were detected. Grazing-resistant species such as sedges (native), timothy (exotic), and club mosses increased and the amount of bare ground increased on some grazed sites. However, the changes within this sampling program alone were not alarming. The amount of bare ground increase was minor (4%), and grass and shrub cover increased in the shrub plots. The inferential power ofthis sample design was limited to the study plots only. Other factors (climate change, succession) were not controlled for using fenced plots and the sensitivity ofthe methods and plots to detect change were limited. For example, the low number oftransects in willow was not adequate to monitor conditions on the entire winter range. Lacking controls, observed changes may have been due to other factors (climate trends, beaver dam abandonment, stream channel changes), not elk herbivory alone. We recommend using a new sampling design that would include controls, pretreatment data, random site selection, and much more replication.

  17. Systematic Review: Audiovisual Interventions for Reducing Preoperative Anxiety in Children Undergoing Elective Surgery

    PubMed Central

    Van Lieshout, Ryan J.; Schmidt, Louis A.; Dobson, Kathleen G.; Buckley, Norman

    2016-01-01

    Objective To examine the effectiveness of Audiovisual (AV) interventions at reducing preoperative anxiety and its associated outcomes in children undergoing elective surgery. Methods A systematic review of randomized controlled trials (RCTs) and nonrandomized studies where the primary outcome was children’s preoperative anxiety was conducted. Secondary outcomes included postoperative pain, behavioral changes, recovery, induction compliance, satisfaction, and cost-effectiveness. The risk of bias of each study was assessed. Results In all, 18 studies were identified. A meta-analytic approach and narrative synthesis of findings were used to summarize the results of the studies. Conclusions This systematic review suggests that AV interventions can be effective in reducing children’s preoperative anxiety. Videos, multi-faceted programs, and interactive games appear to be most effective, whereas music therapy and Internet programs are less effective. While AV interventions appear potentially useful, adequately powered RCTs are required to conclusively pinpoint the components and mechanisms of the most effective AV interventions and guide practice. PMID:26476281

  18. [Homocysteine, vitamin B-12, folic acid and the cognitive decline in the elderly].

    PubMed

    Smach, M A; Naffeti, S; Charfeddine, B; Ben Abdallah, J; Othmen, L B; Letaef, A; Limem, K

    2013-10-01

    Hyperhomocysteinemia is a risk factor for neurological diseases, but the underlying pathophysiology has not been adequately explained. Mild hyperhomocysteinemia, which is sometimes associated with a low plasma level of vitamin B9, B12 and folic acid, is responsible in the toxicity in neural cell by activating NMDA receptor. Indeed, even if vitamin supplementation has clearly proven its efficiency on lowering plasma levels of homocysteine, recent studies do not show any positive effect of vitamin therapy on cognitive function. The hypothesis that this therapy is inefficient has been recently reinforced by two randomized trials on the effects of vitamin supplementation. Several hypotheses still need to be explored: Mechanisms of homocysteine toxicity and that of total uselessness of vitamin supplementation; the possible need to complete the actual data with further, more powerful studies in order to prove the role of homocysteine in the development of neurodegenerative diseases and a clinical effect of vitamin therapy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  19. [Quantitative and qualitative research methods, can they coexist yet?].

    PubMed

    Hunt, Elena; Lavoie, Anne-Marise

    2011-06-01

    Qualitative design is gaining ground in Nursing research. In spite of a relative progress however, the evidence based practice movement continues to dominate and to underline the exclusive value of quantitative design (particularly that of randomized clinical trials) for clinical decision making. In the actual context convenient to those in power making utilitarian decisions on one hand, and facing nursing criticism of the establishment in favor of qualitative research on the other hand, it is difficult to chose a practical and ethical path that values the nursing role within the health care system, keeping us committed to quality care and maintaining researcher's integrity. Both qualitative and quantitative methods have advantages and disadvantages, and clearly, none of them can, by itself, capture, describe and explain reality adequately. Therefore, a balance between the two methods is needed. Researchers bare responsibility to society and science, and they should opt for the appropriate design susceptible to answering the research question, not promote the design favored by the research funding distributors.

  20. Creatine-electrolyte supplementation improves repeated sprint cycling performance: A double blind randomized control study.

    PubMed

    Crisafulli, Daniel L; Buddhadev, Harsh H; Brilla, Lorrie R; Chalmers, Gordon R; Suprak, David N; San Juan, Jun G

    2018-01-01

    Creatine supplementation is recommended as an ergogenic aid to improve repeated sprint cycling performance. Furthermore, creatine uptake is increased in the presence of electrolytes. Prior research examining the effect of a creatine-electrolyte (CE) supplement on repeated sprint cycling performance, however, did not show post-supplementation improvement. The purpose of this double blind randomized control study was to investigate the effect of a six-week CE supplementation intervention on overall and repeated peak and mean power output during repeated cycling sprints with recovery periods of 2 min between sprints. Peak and mean power generated by 23 male recreational cyclists (CE group: n  = 12; 24.0 ± 4.2 years; placebo (P) group: n  = 11; 23.3 ± 3.1 years) were measured on a Velotron ergometer as they completed five 15-s cycling sprints, with 2 min of recovery between sprints, pre- and post-supplementation. Mixed-model ANOVAs were used for statistical analyses. A supplement-time interaction showed a 4% increase in overall peak power (pre: 734 ± 75 W; post: 765 ± 71 W; p  = 0.040; η p 2  = 0.187) and a 5% increase in overall mean power (pre: 586 ± 72 W; post: 615 ± 74 W; p  = 0.019; η p 2  = 0.234) from pre- to post-supplementation for the CE group. For the P group, no differences were observed in overall peak (pre: 768 ± 95 W; post: 772 ± 108 W; p  = 0.735) and overall mean power (pre: 638 ± 77 W; post: 643 ± 92 W; p  = 0.435) from pre- to post-testing. For repeated sprint analysis, peak (pre: 737 ± 88 W; post: 767 ± 92 W; p  = 0.002; η p 2  = 0.380) and mean (pre: 650 ± 92 W; post: 694 ± 87 W; p  < 0.001; η p 2  = 0.578) power output were significantly increased only in the first sprint effort in CE group from pre- to post-supplementation testing. For the P group, no differences were observed for repeated sprint performance. A CE supplement improves overall and repeated short duration sprint cycling performance when sprints are interspersed with adequate recovery periods.

  1. Current role of sodium bicarbonate-based preprocedural hydration for the prevention of contrast-induced acute kidney injury: a meta-analysis.

    PubMed

    Hogan, Shea E; L'Allier, Phillipe; Chetcuti, Stanley; Grossman, P Michael; Nallamothu, Brahmajee K; Duvernoy, Claire; Bates, Eric; Moscucci, Mauro; Gurm, Hitinder S

    2008-09-01

    The optimal hydration strategy for prevention of contrast-induced acute kidney injury (AKI) remains unknown. The purpose of this meta-analysis is to compare the effectiveness of normal saline (NS) versus sodium bicarbonate hydration (NaHCO(3)) for prevention of contrast-induced AKI. We performed a meta-analysis of randomized controlled trials that compared saline-based hydration with sodium bicarbonate-based hydration regimen for prophylaxis of contrast-induced AKI. The literature search included MEDLINE, EMBASE, and Cochrane databases (2000 to October 2007); conference proceedings; and bibliographies of retrieved articles. Information was extracted on study design, sample characteristics, and interventions. Random-effects models were used to calculate summary risk ratios for contrast-induced AKI, need for hemodialysis, and death. Seven trials with 1,307 subjects were included. Preprocedural hydration with sodium bicarbonate was associated with a significant decrease in the rate of contrast-induced AKI (5.96% in the NaHCO(3) arm versus 17.23% in the NS arm, summary risk ratio 0.37, 95% CI 0.18-0.714, P = .005). There was no difference in the rates of postprocedure hemodialysis or death. Formal testing revealed moderate heterogeneity and a strong likelihood of publication bias. Although sodium bicarbonate hydration was found to be superior to NS in prevention of contrast-induced AKI, these results are in the context of study heterogeneity and, likely, publication bias. An adequately powered randomized controlled trial is warranted to define the optimal hydration strategy in patients at high risk of contrast-induced AKI who are scheduled to undergo contrast administration.

  2. Using published data in Mendelian randomization: a blueprint for efficient identification of causal risk factors.

    PubMed

    Burgess, Stephen; Scott, Robert A; Timpson, Nicholas J; Davey Smith, George; Thompson, Simon G

    2015-07-01

    Finding individual-level data for adequately-powered Mendelian randomization analyses may be problematic. As publicly-available summarized data on genetic associations with disease outcomes from large consortia are becoming more abundant, use of published data is an attractive analysis strategy for obtaining precise estimates of the causal effects of risk factors on outcomes. We detail the necessary steps for conducting Mendelian randomization investigations using published data, and present novel statistical methods for combining data on the associations of multiple (correlated or uncorrelated) genetic variants with the risk factor and outcome into a single causal effect estimate. A two-sample analysis strategy may be employed, in which evidence on the gene-risk factor and gene-outcome associations are taken from different data sources. These approaches allow the efficient identification of risk factors that are suitable targets for clinical intervention from published data, although the ability to assess the assumptions necessary for causal inference is diminished. Methods and guidance are illustrated using the example of the causal effect of serum calcium levels on fasting glucose concentrations. The estimated causal effect of a 1 standard deviation (0.13 mmol/L) increase in calcium levels on fasting glucose (mM) using a single lead variant from the CASR gene region is 0.044 (95 % credible interval -0.002, 0.100). In contrast, using our method to account for the correlation between variants, the corresponding estimate using 17 genetic variants is 0.022 (95 % credible interval 0.009, 0.035), a more clearly positive causal effect.

  3. Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.

    PubMed

    Coronado-Montoya, Stephanie; Levis, Alexander W; Kwakkenbos, Linda; Steele, Russell J; Turner, Erick H; Thombs, Brett D

    2016-01-01

    A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses. 108 (87%) of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88%) concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7). Of 21 trial registrations, 13 (62%) remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases. The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.

  4. Effect of short-term administration of cinnamon on blood pressure in patients with prediabetes and type 2 diabetes.

    PubMed

    Akilen, Rajadurai; Pimlott, Zeller; Tsiami, Amalia; Robinson, Nicola

    2013-10-01

    The aim of this study was to systematically review and evaluate the effect of short-term administration of cinnamon on blood pressure regulation in patients with prediabetes and type 2 diabetes by performing a meta-analysis of randomized, placebo-controlled clinical trials. Medical literature for randomized controlled trials (RCTs) of the effect of cinnamon on blood pressure was systematically searched; three original articles published between January 2000 and September 2012 were identified from the MEDLINE database and a hand search of the reference lists of the articles obtained through MEDLINE. The search terms included cinnamon or blood pressure or systolic blood pressure (SBP) or diastolic blood pressure (DBP) or diabetes. A random effects model was used to calculate weighted mean difference and 95% confidence intervals (CI). The pooled estimate of the effect of cinnamon intake on SBP and DBP demonstrated that the use of cinnamon significantly decreased SBP and DBP by 5.39 mm Hg (95% CI, -6.89 to -3.89) and 2.6 mm Hg (95% CI, -4.53 to -0.66) respectively. Consumption of cinnamon (short term) is associated with a notable reduction in SBP and DBP. Although cinnamon shows hopeful effects on BP-lowering potential, it would be premature to recommend cinnamon for BP control because of the limited number of studies available. Thus, undoubtedly a long-term, adequately powered RCT involving a larger number of patients is needed to appraise the clinical potential of cinnamon on BP control among patients with type 2 diabetes mellitus. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Insensitivity of the octahedral spherical hohlraum to power imbalance, pointing accuracy, and assemblage accuracy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Huo, Wen Yi; Zhao, Yiqing; Zheng, Wudi

    2014-11-15

    The random radiation asymmetry in the octahedral spherical hohlraum [K. Lan et al., Phys. Plasmas 21, 0 10704 (2014)] arising from the power imbalance, pointing accuracy of laser quads, and the assemblage accuracy of capsule is investigated by using the 3-dimensional view factor model. From our study, for the spherical hohlraum, the random radiation asymmetry arising from the power imbalance of the laser quads is about half of that in the cylindrical hohlraum; the random asymmetry arising from the pointing error is about one order lower than that in the cylindrical hohlraum; and the random asymmetry arising from the assemblage errormore » of capsule is about one third of that in the cylindrical hohlraum. Moreover, the random radiation asymmetry in the spherical hohlraum is also less than the amount in the elliptical hohlraum. The results indicate that the spherical hohlraum is more insensitive to the random variations than the cylindrical hohlraum and the elliptical hohlraum. Hence, the spherical hohlraum can relax the requirements to the power imbalance and pointing accuracy of laser facility and the assemblage accuracy of capsule.« less

  6. Comparison of Registered and Reported Outcomes in Randomized Clinical Trials Published in Anesthesiology Journals.

    PubMed

    Jones, Philip M; Chow, Jeffrey T Y; Arango, Miguel F; Fridfinnson, Jason A; Gai, Nan; Lam, Kevin; Turkstra, Timothy P

    2017-10-01

    Randomized clinical trials (RCTs) provide high-quality evidence for clinical decision-making. Trial registration is one of the many tools used to improve the reporting of RCTs by reducing publication bias and selective outcome reporting bias. The purpose of our study is to examine whether RCTs published in the top 6 general anesthesiology journals were adequately registered and whether the reported primary and secondary outcomes corresponded to the originally registered outcomes. Following a prespecified protocol, an electronic database was used to systematically screen and extract data from RCTs published in the top 6 general anesthesiology journals by impact factor (Anaesthesia, Anesthesia & Analgesia, Anesthesiology, British Journal of Anaesthesia, Canadian Journal of Anesthesia, and European Journal of Anaesthesiology) during the years 2007, 2010, 2013, and 2015. A manual search of each journal's Table of Contents was performed (in duplicate) to identify eligible RCTs. An adequately registered trial was defined as being registered in a publicly available trials registry before the first patient being enrolled with an unambiguously defined primary outcome. For adequately registered trials, the outcomes registered in the trial registry were compared with the outcomes reported in the article, with outcome discrepancies documented and analyzed by the type of discrepancy. During the 4 years studied, there were 860 RCTs identified, with 102 RCTs determined to be adequately registered (12%). The proportion of adequately registered trials increased over time, with 38% of RCTs being adequately registered in 2015. The most common reason in 2015 for inadequate registration was registering the RCT after the first patient had already been enrolled. Among adequately registered trials, 92% had at least 1 primary or secondary outcome discrepancy. In 2015, 42% of RCTs had at least 1 primary outcome discrepancy, while 90% of RCTs had at least 1 secondary outcome discrepancy. Despite trial registration being an accepted best practice, RCTs published in anesthesiology journals have a high rate of inadequate registration. While mandating trial registration has increased the proportion of adequately registered trials over time, there is still an unacceptably high proportion of inadequately registered RCTs. Among adequately registered trials, there are high rates of discrepancies between registered and reported outcomes, suggesting a need to compare a published RCT with its trial registry entry to be able to fully assess the quality of the study. If clinicians base their decisions on evidence distorted by primary outcome switching, patient care could be negatively affected.

  7. Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency: Twelve-Month Results of the DEFINITIVE AR Study.

    PubMed

    Zeller, Thomas; Langhoff, Ralf; Rocha-Singh, Krishna J; Jaff, Michael R; Blessing, Erwin; Amann-Vesti, Beatrice; Krzanowski, Marek; Peeters, Patrick; Scheinert, Dierk; Torsello, Giovanni; Sixt, Sebastian; Tepe, Gunnar

    2017-09-01

    Studies assessing drug-coated balloons (DCB) for the treatment of femoropopliteal artery disease are encouraging. However, challenging lesions, such as severely calcified, remain difficult to treat with DCB alone. Vessel preparation with directional atherectomy (DA) potentially improves outcomes of DCB. DEFINITIVE AR study (Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency-A Pilot Study of Anti-Restenosis Treatment) was a multicenter randomized trial designed to estimate the effect of DA before DCB to facilitate the development of future end point-driven randomized studies. One hundred two patients with claudication or rest pain were randomly assigned 1:1 to DA+DCB (n=48) or DCB alone (n=54), and 19 additional patients with severely calcified lesions were treated with DA+DCB. Mean lesion length was 11.2±4.0 cm for DA+DCB and 9.7±4.1 cm for DCB ( P =0.05). Predilation rate was 16.7% for DA+DCB versus 74.1% for DCB; postdilation rate was 6.3% for DA+DCB versus 33.3% for DCB. Technical success was superior for DA+DCB (89.6% versus 64.2%; P =0.004). Overall bail-out stenting rate was 3.7%, and rate of flow-limiting dissections was 19% for DCB and 2% for DA+DCB ( P =0.01). One-year primary outcome of angiographic percent diameter stenosis was 33.6±17.7% for DA+DCB versus 36.4±17.6% for DCB ( P =0.48), and clinically driven target lesion revascularization was 7.3% for DA+DCB and 8.0% for DCB ( P =0.90). Duplex ultrasound patency was 84.6% for DA+DCB, 81.3% for DCB ( P =0.78), and 68.8% for calcified lesions. Freedom from major adverse events at 1 year was 89.3% for DA+DCB and 90.0% for DCB ( P =0.86). DA+DCB treatment was effective and safe, but the study was not powered to show significant differences between the 2 methods of revascularization in 1-year follow-up. An adequately powered randomized trial is warranted. http://www.clinicaltrials.gov. Unique Identifier: NCT01366482. Copyright © 2017 The Author(s).

  8. Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency

    PubMed Central

    Langhoff, Ralf; Rocha-Singh, Krishna J.; Jaff, Michael R.; Blessing, Erwin; Amann-Vesti, Beatrice; Krzanowski, Marek; Peeters, Patrick; Scheinert, Dierk; Torsello, Giovanni; Sixt, Sebastian; Tepe, Gunnar

    2017-01-01

    Background— Studies assessing drug-coated balloons (DCB) for the treatment of femoropopliteal artery disease are encouraging. However, challenging lesions, such as severely calcified, remain difficult to treat with DCB alone. Vessel preparation with directional atherectomy (DA) potentially improves outcomes of DCB. Methods and Results— DEFINITIVE AR study (Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency—A Pilot Study of Anti-Restenosis Treatment) was a multicenter randomized trial designed to estimate the effect of DA before DCB to facilitate the development of future end point-driven randomized studies. One hundred two patients with claudication or rest pain were randomly assigned 1:1 to DA+DCB (n=48) or DCB alone (n=54), and 19 additional patients with severely calcified lesions were treated with DA+DCB. Mean lesion length was 11.2±4.0 cm for DA+DCB and 9.7±4.1 cm for DCB (P=0.05). Predilation rate was 16.7% for DA+DCB versus 74.1% for DCB; postdilation rate was 6.3% for DA+DCB versus 33.3% for DCB. Technical success was superior for DA+DCB (89.6% versus 64.2%; P=0.004). Overall bail-out stenting rate was 3.7%, and rate of flow-limiting dissections was 19% for DCB and 2% for DA+DCB (P=0.01). One-year primary outcome of angiographic percent diameter stenosis was 33.6±17.7% for DA+DCB versus 36.4±17.6% for DCB (P=0.48), and clinically driven target lesion revascularization was 7.3% for DA+DCB and 8.0% for DCB (P=0.90). Duplex ultrasound patency was 84.6% for DA+DCB, 81.3% for DCB (P=0.78), and 68.8% for calcified lesions. Freedom from major adverse events at 1 year was 89.3% for DA+DCB and 90.0% for DCB (P=0.86). Conclusions— DA+DCB treatment was effective and safe, but the study was not powered to show significant differences between the 2 methods of revascularization in 1-year follow-up. An adequately powered randomized trial is warranted. Clinical Trial Registration— http://www.clinicaltrials.gov. Unique Identifier: NCT01366482. PMID:28916599

  9. Is Vertical Jump Height an Indicator of Athletes' Power Output in Different Sport Modalities?

    PubMed

    Kons, Rafael L; Ache-Dias, Jonathan; Detanico, Daniele; Barth, Jonathan; Dal Pupo, Juliano

    2018-03-01

    Kons, RL, Ache-Dias, J, Detanico, D, Barth, J, and Dal Pupo, J. Is vertical jump height an indicator of athletes' power output in different sports modalities? J Strength Cond Res 32(3): 708-715, 2018-This study aimed to identify whether the ratio standard is adequate for the scaling of peak power output (PPO) for body mass (BM) in athletes of different sports and to verify classification agreement for athletes involved in different sports using PPO scaled for BM and jump height (JH). One hundred and twenty-four male athletes divided into 3 different groups-combat sports, team sports, and runners-participated in this study. Participants performed the countermovement jump on a force plate. Peak power output and JH were calculated from the vertical ground reaction force. We found different allometric exponents for each modality, allowing the use of the ratio standard for team sports. For combat sports and runners, the ratio standard was not considered adequate, and therefore, a specific allometric exponent for these 2 groups was found. Significant correlations between adjusted PPO for BM (PPOADJ) and JH were found for all modalities, but it was higher for runners (r = 0.81) than team and combat sports (r = 0.63 and 0.65, respectively). Moderate agreement generated by the PPOADJ and JH was verified in team sports (k = 0.47) and running (k = 0.55) and fair agreement in combat sports (k = 0.29). We conclude that the ratio standard seems to be suitable only for team sports; for runners and combat sports, an allometric model seems adequate. The use of JH as an indicator of power output may be considered reasonable only for runners.

  10. Real-time measurement of quality during the compaction of subgrade soils.

    DOT National Transportation Integrated Search

    2012-12-01

    Conventional quality control of subgrade soils during their compaction is usually performed by monitoring moisture content and dry density at a few discrete locations. However, randomly selected points do not adequately represent the entire compacted...

  11. Simple Emergent Power Spectra from Complex Inflationary Physics

    NASA Astrophysics Data System (ADS)

    Dias, Mafalda; Frazer, Jonathan; Marsh, M. C. David

    2016-09-01

    We construct ensembles of random scalar potentials for Nf-interacting scalar fields using nonequilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For Nf=O (few ), these heavily featured scalar potentials give rise to power spectra that are highly nonlinear, at odds with observations. For Nf≫1 , the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realizations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large Nf universality of random matrix theory.

  12. Simple Emergent Power Spectra from Complex Inflationary Physics.

    PubMed

    Dias, Mafalda; Frazer, Jonathan; Marsh, M C David

    2016-09-30

    We construct ensembles of random scalar potentials for N_{f}-interacting scalar fields using nonequilibrium random matrix theory, and use these to study the generation of observables during small-field inflation. For N_{f}=O(few), these heavily featured scalar potentials give rise to power spectra that are highly nonlinear, at odds with observations. For N_{f}≫1, the superhorizon evolution of the perturbations is generically substantial, yet the power spectra simplify considerably and become more predictive, with most realizations being well approximated by a linear power spectrum. This provides proof of principle that complex inflationary physics can give rise to simple emergent power spectra. We explain how these results can be understood in terms of large N_{f} universality of random matrix theory.

  13. Evaluating reliability of WSN with sleep/wake-up interfering nodes

    NASA Astrophysics Data System (ADS)

    Distefano, Salvatore

    2013-10-01

    A wireless sensor network (WSN) (singular and plural of acronyms are spelled the same) is a distributed system composed of autonomous sensor nodes wireless connected and randomly scattered into a geographical area to cooperatively monitor physical or environmental conditions. Adequate techniques and strategies are required to manage a WSN so that it works properly, observing specific quantities and metrics to evaluate the WSN operational conditions. Among them, one of the most important is the reliability. Considering a WSN as a system composed of sensor nodes the system reliability approach can be applied, thus expressing the WSN reliability in terms of its nodes' reliability. More specifically, since often standby power management policies are applied at node level and interferences among nodes may arise, a WSN can be considered as a dynamic system. In this article we therefore consider the WSN reliability evaluation problem from the dynamic system reliability perspective. Static-structural interactions are specified by the WSN topology. Sleep/wake-up standby policies and interferences due to wireless communications can be instead considered as dynamic aspects. Thus, in order to represent and to evaluate the WSN reliability, we use dynamic reliability block diagrams and Petri nets. The proposed technique allows to overcome the limits of Markov models when considering non-linear discharge processes, since they cannot adequately represent the aging processes. In order to demonstrate the effectiveness of the technique, we investigate some specific WSN network topologies, providing guidelines for their representation and evaluation.

  14. A low-power photovoltaic system with energy storage for radio communications: Description and design methodology

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.; Chapman, P. D.; Lewison, A. H.

    1982-01-01

    A low power photovoltaic system was constructed with approximately 500 amp hours of battery energy storage to provide power to an emergency amateur radio communications center. The system can power the communications center for about 72 hours of continuous nonsun operation. Complete construction details and a design methodology algorithm are given with abundant engineering data and adequate theory to allow similar systems to be constructed, scaled up or down, with minimum design effort.

  15. Evaluation of Contribution for Voltage Control Ancillary Services Based on Social Surplus

    NASA Astrophysics Data System (ADS)

    Ueki, Yuji; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

    Reactive power supply plays an important role in active power supply with adequate system voltages. Various pricing mechanism for reactive power supply have been developed and some of them are adopted in some power systems, however they are in a trial stage. The authors also focus on development of a pricing method for reactive power ancillary services. This problem involves two technical issues: rational estimation of the cost associated with reactive power supply and fair and transparent allocation of the estimated cost among the market participants. This paper proposes methods for evaluating the contribution of generators and demands.

  16. Random distributed feedback fiber laser at 2.1  μm.

    PubMed

    Jin, Xiaoxi; Lou, Zhaokai; Zhang, Hanwei; Xu, Jiangming; Zhou, Pu; Liu, Zejin

    2016-11-01

    We demonstrate a random distributed feedback fiber laser at 2.1 μm. A high-power pulsed Tm-doped fiber laser operating at 1.94 μm with a temporal duty ratio of 30% was employed as a pump laser to increase the equivalent incident pump power. A piece of 150 m highly GeO2-doped silica fiber that provides a strong Raman gain and random distributed feedbacks was used to act as the gain medium. The maximum output power reached 0.5 W with the optical efficiency of 9%, which could be further improved by more pump power and optimized fiber length. To the best of our knowledge, this is the first demonstration of random distributed feedback fiber laser at 2 μm band based on Raman gain.

  17. Artemisinin derivatives for treating severe malaria.

    PubMed

    McIntosh, H M; Olliaro, P

    2000-01-01

    Artemisinin derivatives may have advantages over quinoline drugs for treating severe malaria since they are fast acting and effective against quinine resistant malaria parasites. The objective of this review was to assess the effects of artemisinin drugs for severe and complicated falciparum malaria in adults and children. We searched the Cochrane Infectious Diseases Group trials register, Cochrane Controlled Trials Register, Medline, Embase, Science Citation Index, Lilacs, African Index Medicus, conference abstracts and reference lists of articles. We contacted organisations, researchers in the field and drug companies. Randomised and pseudo-randomised trials comparing artemisinin drugs (rectal, intramuscular or intravenous) with standard treatment, or comparisons between artemisinin derivatives in adults or children with severe or complicated falciparum malaria. Eligibility, trial quality assessment and data extraction were done independently by two reviewers. Study authors were contacted for additional information. Twenty three trials are included, allocation concealment was adequate in nine. Sixteen trials compared artemisinin drugs with quinine in 2653 patients. Artemisinin drugs were associated with better survival (mortality odds ratio 0.61, 95% confidence interval 0.46 to 0.82, random effects model). In trials where concealment of allocation was adequate (2261 patients), this was barely statistically significant (odds ratio 0.72, 95% CI 0.54 to 0.96, random effects model). In 1939 patients with cerebral malaria, mortality was also lower with artemisinin drugs overall (odds ratio 0.63, 95% CI 0.44 to 0.88, random effects model). The difference was not significant however when only trials reporting adequate concealment of allocation were analysed (odds ratio 0.78, 95% CI 0.55 to 1.10, random effects model) based on 1607 patients. No difference in neurological sequelae was shown. Compared with quinine, artemisinin drugs showed faster parasite clearance from the blood and similar adverse effects. The evidence suggests that artemisinin drugs are no worse than quinine in preventing death in severe or complicated malaria. No artemisinin derivative appears to be better than the others.

  18. 78 FR 46549 - Approval and Promulgation of Implementation Plans; Idaho: State Board Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... such board or body or the head of an executive agency with similar powers be adequately disclosed.'' 42... Requirements Idaho Code Sec. 39-107, Board--Composition--Officers-- Compensation--Powers--Subpoena--Depositions... regard to their knowledge of and interest in solid waste; two (2) members shall be chosen for their...

  19. A Report on Deliverable Six: Develop a Concept Design for a Ruggedized, Lightweight, Portable, Powered Handheld Suction Device

    DTIC Science & Technology

    reflect it. There are commercially available manual and powered suction devices on the market , and several are specifically advertised for use in...combine to suggest that no device on the market meets even the most basic requirements of being small, lightweight, rugged, and demonstrating adequate

  20. Customizing elastic pressure bandages for reuse to a predetermined, sub-bandage pressure: A randomized controlled trial.

    PubMed

    Sermsathanasawadi, Nuttawut; Tarapongpun, Tanakorn; Pianchareonsin, Rattana; Puangpunngam, Nattawut; Wongwanit, Chumpol; Chinsakchai, Khamin; Mutirangura, Pramook; Ruangsetakit, Chanean

    2017-01-01

    Objective A randomized clinical trial was performed to compare the effectiveness of unmarked bandages and customized bandages with visual markers in reproducing the desired sub-bandage pressure during self-bandaging by patients. Method Ninety patients were randomly allocated to two groups ("customized bandages" and "unmarked bandages") and asked to perform self-bandaging three times. The achievement of a pressure between 35 and 45 mmHg in at least two of the three attempts was defined as adequate quality. Results Adequate quality was achieved by 33.0% when applying the unmarked bandages, and 60.0% when applying the customized bandages ( p = 0.02). Use of the customized bandage and previous experience of bandaging were independent predictors for the achievement of the predetermined sub-bandage pressure ( p = 0.005 and p = 0.021, respectively). Conclusion Customized bandages may achieve predetermined sub-bandage pressures more closely than standard, unmarked, compression bandages. Clinical trials registration ClinicalTrials.gov (NCT02729688). Effectiveness of a Pressure Indicator Guided and a Conventional Bandaging in Treatment of Venous Leg Ulcer. https://clinicaltrials.gov/ct2/show/NCT02729688.

  1. Effects of a Meditation Program on Nurses' Power and Quality of Life.

    PubMed

    Chang, Sun Ju; Kwak, Eun Young; Hahm, Bong-Jin; Seo, Se Hee; Lee, Da Woon; Jang, Sun Joo

    2016-07-01

    This study evaluated the effects of meditation programs on nurses' power and quality of life. In this study, Barrett's power theory derived from Rogers' unitary human being science was used as a theoretical framework. A randomized controlled design with 50 recruited and randomly allocated participants was used. The results demonstrated that the eight-week meditation program significantly improved nurses' power and quality of life. These results suggest that meditation has positive effects on power and quality of life. © The Author(s) 2016.

  2. The conditional power of randomization tests for single-case effect sizes in designs with randomized treatment order: A Monte Carlo simulation study.

    PubMed

    Michiels, Bart; Heyvaert, Mieke; Onghena, Patrick

    2018-04-01

    The conditional power (CP) of the randomization test (RT) was investigated in a simulation study in which three different single-case effect size (ES) measures were used as the test statistics: the mean difference (MD), the percentage of nonoverlapping data (PND), and the nonoverlap of all pairs (NAP). Furthermore, we studied the effect of the experimental design on the RT's CP for three different single-case designs with rapid treatment alternation: the completely randomized design (CRD), the randomized block design (RBD), and the restricted randomized alternation design (RRAD). As a third goal, we evaluated the CP of the RT for three types of simulated data: data generated from a standard normal distribution, data generated from a uniform distribution, and data generated from a first-order autoregressive Gaussian process. The results showed that the MD and NAP perform very similarly in terms of CP, whereas the PND performs substantially worse. Furthermore, the RRAD yielded marginally higher power in the RT, followed by the CRD and then the RBD. Finally, the power of the RT was almost unaffected by the type of the simulated data. On the basis of the results of the simulation study, we recommend at least 20 measurement occasions for single-case designs with a randomized treatment order that are to be evaluated with an RT using a 5% significance level. Furthermore, we do not recommend use of the PND, because of its low power in the RT.

  3. Stochastic models for atomic clocks

    NASA Technical Reports Server (NTRS)

    Barnes, J. A.; Jones, R. H.; Tryon, P. V.; Allan, D. W.

    1983-01-01

    For the atomic clocks used in the National Bureau of Standards Time Scales, an adequate model is the superposition of white FM, random walk FM, and linear frequency drift for times longer than about one minute. The model was tested on several clocks using maximum likelihood techniques for parameter estimation and the residuals were acceptably random. Conventional diagnostics indicate that additional model elements contribute no significant improvement to the model even at the expense of the added model complexity.

  4. Random regression analyses using B-splines functions to model growth from birth to adult age in Canchim cattle.

    PubMed

    Baldi, F; Alencar, M M; Albuquerque, L G

    2010-12-01

    The objective of this work was to estimate covariance functions using random regression models on B-splines functions of animal age, for weights from birth to adult age in Canchim cattle. Data comprised 49,011 records on 2435 females. The model of analysis included fixed effects of contemporary groups, age of dam as quadratic covariable and the population mean trend taken into account by a cubic regression on orthogonal polynomials of animal age. Residual variances were modelled through a step function with four classes. The direct and maternal additive genetic effects, and animal and maternal permanent environmental effects were included as random effects in the model. A total of seventeen analyses, considering linear, quadratic and cubic B-splines functions and up to seven knots, were carried out. B-spline functions of the same order were considered for all random effects. Random regression models on B-splines functions were compared to a random regression model on Legendre polynomials and with a multitrait model. Results from different models of analyses were compared using the REML form of the Akaike Information criterion and Schwarz' Bayesian Information criterion. In addition, the variance components and genetic parameters estimated for each random regression model were also used as criteria to choose the most adequate model to describe the covariance structure of the data. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most adequate to describe the covariance structure of the data. Random regression models using B-spline functions as base functions fitted the data better than Legendre polynomials, especially at mature ages, but higher number of parameters need to be estimated with B-splines functions. © 2010 Blackwell Verlag GmbH.

  5. Hot rocket plume experiment - Survey and conceptual design. [of rhenium-iridium bipropellants

    NASA Technical Reports Server (NTRS)

    Millard, Jerry M.; Luan, Taylor W.; Dowdy, Mack W.

    1992-01-01

    Attention is given to a space-borne engine plume experiment study to fly an experiment which will both verify and quantify the reduced contamination from advanced rhenium-iridium earth-storable bipropellant rockets (hot rockets) and provide a correlation between high-fidelity, in-space measurements and theoretical plume and surface contamination models. The experiment conceptual design is based on survey results from plume and contamination technologists throughout the U.S. With respect to shuttle use, cursory investigations validate Hitchhiker availability and adaptability, adequate remote manipulator system (RMS) articulation and dynamic capability, acceptable RMS attachment capability, adequate power and telemetry capability, and adequate flight altitude and attitude/orbital capability.

  6. Work-related CBT versus vocational services as usual for unemployed persons with social anxiety disorder: A randomized controlled pilot trial.

    PubMed

    Himle, Joseph A; Bybee, Deborah; Steinberger, Edward; Laviolette, Wayne T; Weaver, Addie; Vlnka, Sarah; Golenberg, Zipora; Levine, Debra Siegel; Heimberg, Richard G; O'Donnell, Lisa A

    2014-12-01

    We designed and pilot-tested a group-based, work-related cognitive-behavioral therapy (WCBT) for unemployed individuals with social anxiety disorder (SAD). WCBT, delivered in a vocational service setting by vocational service professionals, aims to reduce social anxiety and enable individuals to seek, obtain, and retain employment. We compared WCBT to a vocational services as usual control condition (VSAU). Participants were unemployed, homeless, largely African American, vocational service-seeking adults with SAD (N = 58), randomized to receive either eight sessions of WCBT plus VSAU or VSAU alone and followed three months post-treatment. Multilevel modeling revealed significantly greater reductions in social anxiety, general anxiety, depression, and functional impairment for WCBT compared to VSAU. Coefficients for job search activity and self-efficacy indicated greater increases for WCBT. Hours worked per week in the follow-up period did not differ between the groups, but small sample size and challenges associated with measuring work hours may have contributed to this finding. Overall, the results of this study suggest that unemployed persons with SAD can be effectively treated with specialized work-related CBT administered by vocational service professionals. Future testing of WCBT with a larger sample, a longer follow-up period, and adequate power to assess employment outcomes is warranted. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. The White-test helps to reduce biliary leakage in liver resection: a systematic review and meta-analysis.

    PubMed

    Linke, Richard; Ulrich, Frank; Bechstein, Wolf O; Schnitzbauer, Andreas A

    2015-01-01

    Bile leakage testing may help to detect and reduce the incidence of biliary leakage after hepatic resection. This review was performed to investigate the value of the White-test in identifying intraoperative biliary leakage and avoiding postoperative leakage. A systematic review and meta-analysis was performed. Two researchers performed literature research. Primary outcome measure was the incidence of post-hepatectomy biliary leakage; secondary outcome measure was the ability of detecting intraoperative biliary leakage with the help of the White-test. A total of 4 publications (including original data from our center) were included in the analysis. Evidence levels of the included studies had medium quality of 2b (individual cohort studies including low quality randomized controlled trials). Use of the White-test led to a significant reduction of post-operative biliary leakage [OR: 0.3 (95% CI: 0.14, 0.63), p = 0.002] and led to a significant higher intraoperative detection of biliary leakages [OR: 0.03 (95%CI: 0.02, 0.07), p < 0.00001]. Existing evidence implicates the use of the White-test after hepatic resection to identify bile leaks intraoperatively and thus reduce incidence of post-operative biliary leakage. Nonetheless, there is a requirement for a high-quality randomized controlled trial with adequately powered sample-size to confirm findings from the above described studies and further increase evidence in this field.

  8. Cold therapy to prevent paclitaxel-induced peripheral neuropathy.

    PubMed

    Griffiths, Claire; Kwon, Nancy; Beaumont, Jennifer L; Paice, Judith A

    2018-04-21

    This case-control study was designed to assess the efficacy of cryotherapy to prevent paclitaxel-induced painful peripheral neuropathy in women with breast cancer. Participants served as their own paired control, with randomization of the cooled glove/sock to either the dominant or the non-dominant hand/foot, worn for 15 min prior to, during, and 15 min after completion of the paclitaxel infusion. Outcome measures included the Neuropathic Pain Symptom Inventory, the Brief Pain Inventory, and quantitative sensory testing. Data were measured at each of six time points-baseline, post-treatment (approximately 2 weeks after the last paclitaxel infusion), and at the first, fifth, ninth, and final weekly paclitaxel treatments. Of 29 randomized participants, 20 (69%) received at least one cryotherapy treatment, and 11 (38%) received all four cryotherapy treatments. Ten (34%) participants could not tolerate the cryotherapy, and six (21%) declined further participation at some point during the trial. Only seven participants (24%) were available for the final post-chemotherapy QST and questionnaires. There were no significant differences in measures of neuropathy or pain between treated and untreated hands or feet. Strategies to prevent painful peripheral neuropathy are urgently needed. In this current trial, dropout due to discomfort precluded adequate power to fully understand the potential benefits of cryotherapy. Much more research is needed to discover safe and effective preventive strategies that can be easily implemented within busy infusion centers.

  9. Respiratory protection during simulated emergency pediatric life support: a randomized, controlled, crossover study.

    PubMed

    Schumacher, Jan; Gray, Stuart A; Michel, Sophie; Alcock, Roger; Brinker, Andrea

    2013-02-01

    Emergency pediatric life support (EPLS) of children infected with transmissible respiratory diseases requires adequate respiratory protection for medical first responders. Conventional air-purifying respirators (APR) and modern loose-fitting powered air-purifying respirator-hoods (PAPR-hood) may have a different impact during pediatric resuscitation and therefore require evaluation. This study investigated the influence of APRs and PAPR-hoods during simulated pediatric cardiopulmonary resuscitation. Study design was a randomized, controlled, crossover study. Sixteen paramedics carried out a standardized EPLS scenario inside an ambulance, either unprotected (control) or wearing a conventional APR or a PAPR-hood. Treatment times and wearer comfort were determined and compared. All paramedics completed the treatment objectives of the study arms without adverse events. Study subjects reported that communication, dexterity and mobility were significantly better in the APR group, whereas the heat-build-up was significantly less in the PAPR-hood group. Treatment times compared to the control group did not significantly differ for the APR group but did with the PAPR-hood group (261±12 seconds for the controls, 275±9 seconds for the conventional APR and 286±13 seconds for the PAPR-hood group, P < .05. APRs showed a trend to better treatment times compared to PAPR-hoods during simulated pediatric cardiopulmonary resuscitation. Study participants rated mobility, ease of communication and dexterity with the tight-fitting APR system significantly better compared to the loose-fitting PAPR-hood.

  10. Asking Sensitive Questions: A Statistical Power Analysis of Randomized Response Models

    ERIC Educational Resources Information Center

    Ulrich, Rolf; Schroter, Hannes; Striegel, Heiko; Simon, Perikles

    2012-01-01

    This article derives the power curves for a Wald test that can be applied to randomized response models when small prevalence rates must be assessed (e.g., detecting doping behavior among elite athletes). These curves enable the assessment of the statistical power that is associated with each model (e.g., Warner's model, crosswise model, unrelated…

  11. False Operation of Static Random Access Memory Cells under Alternating Current Power Supply Voltage Variation

    NASA Astrophysics Data System (ADS)

    Sawada, Takuya; Takata, Hidehiro; Nii, Koji; Nagata, Makoto

    2013-04-01

    Static random access memory (SRAM) cores exhibit susceptibility against power supply voltage variation. False operation is investigated among SRAM cells under sinusoidal voltage variation on power lines introduced by direct RF power injection. A standard SRAM core of 16 kbyte in a 90 nm 1.5 V technology is diagnosed with built-in self test and on-die noise monitor techniques. The sensitivity of bit error rate is shown to be high against the frequency of injected voltage variation, while it is not greatly influenced by the difference in frequency and phase against SRAM clocking. It is also observed that the distribution of false bits is substantially random in a cell array.

  12. The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography.

    PubMed

    Lee, Jeffrey S; Cleaver, Gerald B

    2017-10-01

    In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.

  13. 75 FR 5585 - Notice of a Regional Project Waiver of Section 1605 (Buy American Requirement) of the American...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... at the ACSD's North Plant wastewater treatment plant (WWTP), and to produce electrical power for on... turbine generator manufactured in the United States is of adequate capacity to meet the electrical power..., (2) Ormat Technologies, Inc, in Israel, and (3) Adoratec, in Germany. This is a project specific...

  14. An Ecological Perspective of Power in Transformational Learning: A Case Study of Ethical Vegans.

    ERIC Educational Resources Information Center

    McDonald, Barbara; Cervero, Ronald M.; Courtenay, Bradley C.

    1999-01-01

    In-depth interviews with 12 ethical vegans revealed the process of becoming vegetarian. Transformative learning proved to be a journey rather than a one-time decision. Mezirow's transformative theory does not adequately account for the power relations central to this process. Therefore, transformative learning should be viewed more holistically.…

  15. 40 CFR 35.713 - Eligible recipients.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Monitoring (section 28) § 35.713 Eligible recipients. (a) The Regional Administrator will treat a Tribe or... an existing government exercising substantial governmental duties and powers; (3) Has adequate...

  16. Randomized comparison of 3 different-sized biopsy forceps for quality of sampling in Barrett’s esophagus

    PubMed Central

    Gonzalez, Susana; Yu, Woojin M.; Smith, Michael S.; Slack, Kristen N.; Rotterdam, Heidrun; Abrams, Julian A.; Lightdale, Charles J.

    2011-01-01

    Background Several types of forceps are available for use in sampling Barrett’s esophagus (BE). Few data exist with regard to biopsy quality for histologic assessment. Objective To evaluate sampling quality of 3 different forceps in patients with BE. Design Single-center, randomized clinical trial. Patients Consecutive patients with BE undergoing upper endoscopy. Interventions Patients randomized to have biopsy specimens taken with 1 of 3 types of forceps: standard, large capacity, or jumbo. Main Outcome Measurements Specimen adequacy was defined a priori as a well-oriented biopsy sample 2 mm or greater in diameter and with at least muscularis mucosa present. Results A total of 65 patients were enrolled and analyzed (standard forceps, n = 21; large-capacity forceps, n = 21; jumbo forceps, n = 23). Compared with jumbo forceps, a significantly higher proportion of biopsy samples with large-capacity forceps were adequate (37.8% vs 25.2%, P = .002). Of the standard forceps biopsy samples, 31.9% were adequate, which was not significantly different from specimens taken with large-capacity (P = .20) or jumbo (P = .09) forceps. Biopsy specimens taken with jumbo forceps had the largest diameter (median, 3.0 mm vs 2.5 mm [standard] vs 2.8 mm [large capacity]; P = .0001). However, jumbo forceps had the lowest proportion of specimens that were well oriented (overall P = .001). Limitations Heterogeneous patient population precluded dysplasia detection analyses. Conclusions Our results challenge the requirement of jumbo forceps and therapeutic endoscopes to properly perform the Seattle protocol. We found that standard and large-capacity forceps used with standard upper endoscopes produced biopsy samples at least as adequate as those obtained with jumbo forceps and therapeutic endoscopes in patients with BE. PMID:21034895

  17. Bystander fatigue and CPR quality by older bystanders: a randomized crossover trial comparing continuous chest compressions and 30:2 compressions to ventilations.

    PubMed

    Liu, Shawn; Vaillancourt, Christian; Kasaboski, Ann; Taljaard, Monica

    2016-11-01

    This study sought to measure bystander fatigue and cardiopulmonary resuscitation (CPR) quality after five minutes of CPR using the continuous chest compression (CCC) versus the 30:2 chest compression to ventilation method in older lay persons, a population most likely to perform CPR on cardiac arrest victims. This randomized crossover trial took place at three tertiary care hospitals and a seniors' center. Participants were aged ≥55 years without significant physical limitations (frailty score ≤3/7). They completed two 5-minute CPR sessions (using 30:2 and CCC) on manikins; sessions were separated by a rest period. We used concealed block randomization to determine CPR method order. Metronome feedback maintained a compression rate of 100/minute. We measured heart rate (HR), mean arterial pressure (MAP), and Borg Exertion Scale. CPR quality measures included total number of compressions and number of adequate compressions (depth ≥5 cm). Sixty-three participants were enrolled: mean age 70.8 years, female 66.7%, past CPR training 60.3%. Bystander fatigue was similar between CPR methods: mean difference in HR -0.59 (95% CI -3.51-2.33), MAP 1.64 (95% CI -0.23-3.50), and Borg 0.46 (95% CI 0.07-0.84). Compared to 30:2, participants using CCC performed more chest compressions (480.0 v. 376.3, mean difference 107.7; p<0.0001) and more adequate chest compressions (381.5 v. 324.9, mean difference. 62.0; p=0.0001), although good compressions/minute declined significantly faster with the CCC method (p=0.0002). CPR quality decreased significantly faster when performing CCC compared to 30:2. However, performing CCC produced more adequate compressions overall with a similar level of fatigue compared to the 30:2 method.

  18. Hypothesis testing in clinical trials.

    PubMed

    Green, S B

    2000-08-01

    In designing and analyzing any clinical trial, two issues related to patient heterogeneity must be considered: (1) the effect of chance and (2) the effect of bias. These issues are addressed by enrolling adequate numbers of patients in the study and using randomization for treatment assignment. An "intention-to-treat" analysis of outcome data includes all individuals randomized and counted in the group to which they are randomized. There is an increased risk of spurious results with a greater number of subgroup analyses, particularly when these analyses are data derived. Factorial designs are sometimes appropriate and can lead to efficiencies by addressing more than one comparison of interventions in a single trial.

  19. Solar Power Satellite (SPS) solid-state antenna power combiner

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A low loss power-combining microstrip antenna suitable for solid state solar power satellite (SPS) application was developed. A unique approach for performing both the combining and radiating function in a single cavity-type circuit was verified, representing substantial refinements over previous demonstration models in terms of detailed geometry to obtain good matching and adequate bandwidth at the design frequency. The combiner circuit was designed, built, and tested and the overall results support the view that the solid state power-combining antenna approach is a viable candidate for a solid state SPS antenna building block.

  20. A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

    ERIC Educational Resources Information Center

    Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben

    2016-01-01

    The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…

  1. Power in randomized group comparisons: the value of adding a single intermediate time point to a traditional pretest-posttest design.

    PubMed

    Venter, Anre; Maxwell, Scott E; Bolig, Erika

    2002-06-01

    Adding a pretest as a covariate to a randomized posttest-only design increases statistical power, as does the addition of intermediate time points to a randomized pretest-posttest design. Although typically 5 waves of data are required in this instance to produce meaningful gains in power, a 3-wave intensive design allows the evaluation of the straight-line growth model and may reduce the effect of missing data. The authors identify the statistically most powerful method of data analysis in the 3-wave intensive design. If straight-line growth is assumed, the pretest-posttest slope must assume fairly extreme values for the intermediate time point to increase power beyond the standard analysis of covariance on the posttest with the pretest as covariate, ignoring the intermediate time point.

  2. Abortion legalized: challenges ahead.

    PubMed

    Singh, M; Jha, R

    2007-01-01

    To see whether advocacy for abortion law and comprehensive abortion care (CAC) sites after legalization of abortion in Nepal is adequate among educated people (above school leaving certificate). 150 participants were assigned randomly who agreed to be in the survey and were given structured questionnaires to find out their perception of abortion and CAC sites. Majority know abortion is legalized and majority have positive attitude about legalization of abortion, however majority are not aware of abortion service in CAC sites and none knew the cost of abortion service. Proper and adequate advocacy of the new abortion law and CAC service is essential.

  3. The effect of propofol-remifentanil anesthesia on selected seizure quality indices in electroconvulsive therapy.

    PubMed

    Dinwiddie, Stephen H; Glick, David B; Goldman, Morris B

    2012-07-01

    Use of a short-acting opiate to potentiate anesthetic induction agents has been shown to increase seizure duration in electroconvulsive therapy (ECT), but little is known of the effect of this combination on indices of seizure quality. To determine whether anesthetic modality affects commonly provided indices of seizure quality. Twenty-five subjects were given propofol 2 mg/kg body weight for their first ECT session, at which time seizure threshold was titrated. Subjects thereafter alternated between that anesthetic regimen or propofol 0.5 mg/kg plus remifentanil 1 mcg/kg. Linear mixed models with random subject effect, adjusting for electrode placement, electrical charge, and number of treatments, were fit to estimate effect of anesthesia on seizure duration and several standard seizure quality indices (average seizure energy, time to peak electroencephalography (EEG) power, maximum sustained power, interhemispheric coherence, early and midictal EEG amplitude, and maximum sustained interhemispheric EEG coherence). Propofol-remifentanil anesthesia significantly lengthened seizure duration and was associated with longer time to reach maximal EEG power and coherence as well as maximal degree of interhemispheric EEG coherence. No effect was seen on early ictal amplitude or average seizure energy index. Propofol-remifentanil anesthesia prolongs seizure duration and has a significant effect on some, but not all, measures of seizure quality. This effect may be of some benefit in cases where adequate seizures are otherwise difficult to elicit. Varying anesthetic technique may allow more precise investigation of the relationships between and relative impacts of commonly used seizure quality indices on clinical outcomes and ECT-related cognitive side effects. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Analysing Command Challenges Using the Command and Control Framework: Pilot Study Results

    DTIC Science & Technology

    2003-02-01

    allocation of resources (2), adequate staff, abuse of power Primary Rank Level 8 % Rank too low Abuse of power/authority (14), gender Use of Power 58...Advisory Board on Gender Integration and Employment Equity: 2000 Annual Report. Ottawa: Department of National Defence. 8. Adams-Roy, J.E., MacLennan...Opportunity (e.g., for socialisation ) Explain: = NoDl Yes R] :Other Explain: 36 DRDC Toronto TR 2003-034 PART D - GENERAL 6. Overall Assessment = In your

  5. HOMER: The Micropower Optimization Model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    2004-03-01

    HOMER, the micropower optimization model, helps users to design micropower systems for off-grid and grid-connected power applications. HOMER models micropower systems with one or more power sources including wind turbines, photovoltaics, biomass power, hydropower, cogeneration, diesel engines, cogeneration, batteries, fuel cells, and electrolyzers. Users can explore a range of design questions such as which technologies are most effective, what size should components be, how project economics are affected by changes in loads or costs, and is the renewable resource adequate.

  6. Acute Respiratory Distress Syndrome Measurement Error. Potential Effect on Clinical Study Results

    PubMed Central

    Cooke, Colin R.; Iwashyna, Theodore J.; Hofer, Timothy P.

    2016-01-01

    Rationale: Identifying patients with acute respiratory distress syndrome (ARDS) is a recognized challenge. Experts often have only moderate agreement when applying the clinical definition of ARDS to patients. However, no study has fully examined the implications of low reliability measurement of ARDS on clinical studies. Objectives: To investigate how the degree of variability in ARDS measurement commonly reported in clinical studies affects study power, the accuracy of treatment effect estimates, and the measured strength of risk factor associations. Methods: We examined the effect of ARDS measurement error in randomized clinical trials (RCTs) of ARDS-specific treatments and cohort studies using simulations. We varied the reliability of ARDS diagnosis, quantified as the interobserver reliability (κ-statistic) between two reviewers. In RCT simulations, patients identified as having ARDS were enrolled, and when measurement error was present, patients without ARDS could be enrolled. In cohort studies, risk factors as potential predictors were analyzed using reviewer-identified ARDS as the outcome variable. Measurements and Main Results: Lower reliability measurement of ARDS during patient enrollment in RCTs seriously degraded study power. Holding effect size constant, the sample size necessary to attain adequate statistical power increased by more than 50% as reliability declined, although the result was sensitive to ARDS prevalence. In a 1,400-patient clinical trial, the sample size necessary to maintain similar statistical power increased to over 1,900 when reliability declined from perfect to substantial (κ = 0.72). Lower reliability measurement diminished the apparent effectiveness of an ARDS-specific treatment from a 15.2% (95% confidence interval, 9.4–20.9%) absolute risk reduction in mortality to 10.9% (95% confidence interval, 4.7–16.2%) when reliability declined to moderate (κ = 0.51). In cohort studies, the effect on risk factor associations was similar. Conclusions: ARDS measurement error can seriously degrade statistical power and effect size estimates of clinical studies. The reliability of ARDS measurement warrants careful attention in future ARDS clinical studies. PMID:27159648

  7. 40 CFR 35.693 - Eligible recipients.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...(g)) § 35.693 Eligible recipients. (a) The Regional Administrator will treat a Tribe or Intertribal... exercising substantial governmental duties and powers; (3) Has adequate authority to carry out the grant...

  8. Effect Evaluation of a Randomized Trial to Reduce Infectious Illness and Illness-related Absenteeism Among Schoolchildren: The Hi Five Study.

    PubMed

    Denbæk, Anne Maj; Andersen, Anette; Bonnesen, Camilla Thørring; Laursen, Bjarne; Ersbøll, Annette Kjær; Due, Pernille; Johansen, Anette

    2018-01-01

    Previous school-based hand hygiene interventions have reported to successfully reduce infectious illness among schoolchildren. But few studies have tested the effect in large populations with adequate statistical power and analyses. The aim of this study was to evaluate whether a school-based multicomponent intervention to improve handwashing among schoolchildren, the Hi Five study, succeeded in reducing infectious illness and illness-related absenteeism in schools. The Hi Five study was a three-armed cluster-randomized controlled trial involving 43 randomly selected Danish schools; two intervention arms involving 14 schools each, and 15 control schools. Infectious illness days, infectious illness episodes and illness-related absenteeism were estimated in multilevel regressions, based on available cases of text messages answered by parents and based on questionnaire data reported by schoolchildren, respectively. At follow-up, children in the intervention schools did not differ from the control schools in number of illness days [odds ratio (OR)I-arm I: 0.91 (0.77-1.07) and ORI-arm II: 0.94 (0.79-1.12)] and illness episodes [ORI-arm I: 0.95 (0.81-1.11) and ORI-arm II: 0.98 (0.84-1.16)] or in reporting illness-related absenteeism [ORI-arm I: 1.09 (0.83-1.43) & ORI-arm II: 1.06 (0.81-1.40)]. The multicomponent Hi Five intervention achieved no difference in the number of illness days, illness episodes or illness-related absenteeism among children in intervention schools compared with control schools. It is noteworthy that one of the main components in the intervention, a mandatory daily handwashing before lunch, was only implemented by 1 of 3 of teachers in intervention schools.

  9. Cognitive-behavioural suicide prevention for male prisoners: a pilot randomized controlled trial.

    PubMed

    Pratt, D; Tarrier, N; Dunn, G; Awenat, Y; Shaw, J; Ulph, F; Gooding, P

    2015-12-01

    Prisoners have an exceptional risk of suicide. Cognitive-behavioural therapy for suicidal behaviour has been shown to offer considerable potential, but has yet to be formally evaluated within prisons. This study investigated the feasibility of delivering and evaluating a novel, manualized cognitive-behavioural suicide prevention (CBSP) therapy for suicidal male prisoners. A pilot randomized controlled trial of CBSP in addition to treatment as usual (CBSP; n = 31) compared with treatment as usual (TAU; n = 31) alone was conducted in a male prison in England. The primary outcome was self-injurious behaviour occurring within the past 6 months. Secondary outcomes were dimensions of suicidal ideation, psychiatric symptomatology, personality dysfunction and psychological determinants of suicide, including depression and hopelessness. The trial was prospectively registered (number ISRCTN59909209). Relative to TAU, participants receiving CBSP therapy achieved a significantly greater reduction in suicidal behaviours with a moderate treatment effect [Cohen's d = -0.72, 95% confidence interval -1.71 to 0.09; baseline mean TAU: 1.39 (S.D. = 3.28) v. CBSP: 1.06 (S.D. = 2.10), 6 months mean TAU: 1.48 (S.D. = 3.23) v. CBSP: 0.58 (S.D. = 1.52)]. Significant improvements were achieved on measures of psychiatric symptomatology and personality dysfunction. Improvements on psychological determinants of suicide were non-significant. More than half of the participants in the CBSP group achieved a clinically significant recovery by the end of therapy, compared with a quarter of the TAU group. The delivery and evaluation of CBSP therapy within a prison is feasible. CBSP therapy offers significant promise in the prevention of prison suicide and an adequately powered randomized controlled trial is warranted.

  10. Randomized trial of a telephone-based weight loss intervention in postmenopausal women with breast cancer receiving letrozole: the LISA trial.

    PubMed

    Goodwin, Pamela J; Segal, Roanne J; Vallis, Michael; Ligibel, Jennifer A; Pond, Gregory R; Robidoux, André; Blackburn, George L; Findlay, Brian; Gralow, Julie R; Mukherjee, Som; Levine, Mark; Pritchard, Kathleen I

    2014-07-20

    Obesity is associated with poor outcomes in women with operable breast cancer. Lifestyle interventions (LIs) that help women reduce their weight may improve outcomes. We conducted a multicenter randomized trial comparing mail-based delivery of general health information alone or combined with a 24-month standardized, telephone-based LI that included diet (500 to 1,000 kcal per day deficit) and physical activity (150 to 200 minutes of moderate-intensity physical activity per week) goals to achieve weight loss (up to 10%). Women receiving adjuvant letrozole for T1-3N0-3M0 breast cancer with a body mass index (BMI) ≥ 24 kg/m(2) were eligible. Weight was measured in the clinic, and self-report physical activity, quality-of-life (QOL), and diet questionnaires were completed. The primary outcome was disease-free survival. Accrual was terminated at 338 of 2,150 planned patients because of loss of funding. Mean weight loss was significantly (P < .001) greater in the LI arm versus the comparison arm (4.3 v 0.6 kg or 5.3% v 0.7% at 6 months and 3.1 v 0.3 kg or 3.6% v 0.4% at 24 months) and occurred consistently across strata (BMI 24 to < 30 v ≥ 30 kg/m(2); prior v no prior adjuvant chemotherapy). Weight loss was greatest in those with higher baseline levels of moderate-intensity physical activity or improvement in QOL. Hospitalization rates and medical events were similar. A telephone-based LI led to significant weight loss that was still evident at 24 months, without adverse effects on QOL, hospitalizations, or medical events. Adequately powered randomized trials with cancer end points are needed. © 2014 by American Society of Clinical Oncology.

  11. Rationale and Design of Randomized Evaluation of Aggressive or Moderate Lipid Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) Trial.

    PubMed

    Miyauchi, Katsumi; Kimura, Takeshi; Shimokawa, Hiroaki; Daida, Hiroyuki; Iimuro, Satoshi; Iwata, Hiroshi; Ozaki, Yukio; Sakuma, Ichiro; Nakagawa, Yoshihisa; Hibi, Kiyoshi; Hiro, Takafumi; Fukumoto, Yoshihiro; Hokimoto, Seiji; Ohashi, Yasuo; Ohtsu, Hiroshi; Saito, Yasushi; Matsuzaki, Masunori; Nagai, Ryozo

    2018-03-30

    Large-scale clinical trials in patients in Western countries with coronary artery disease (CAD) have found that aggressive lipid-lowering therapy using high-dose statins reduces cardiovascular (CV) events further than low-dose statins. However, such evidence has not yet been fully established in Asian populations, including in Japan. The Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy with Pitavastatin in Coronary Artery Disease (REAL-CAD) study addresses whether intensification of statin therapy improves clinical outcomes in Japanese patients with CAD.REAL-CAD is a prospective, multicenter, randomized, open-label, blinded-endpoint, physician-initiated phase 4 trial in Japan. The study will recruit up to 12,600 patients with stable CAD. Patients are assigned to receive either pitavastatin 1 mg/day or pitavastatin 4 mg/day. LDL-C levels are expected to reach approximate mean values of 100 mg/dL in the low-dose pitavastatin group and 80 mg/dL in the high-dose group. The primary endpoint is the time to occurrence of a major CV event, including CV death, non-fatal myocardial infarction, non-fatal ischemic stroke, and unstable angina requiring emergency hospitalization during an average of 5 years. The large number of patients and the long follow-up period in the REAL-CAD study should ensure that there is adequate power to definitively determine if reducing LDL-C levels to approximately 80 mg/dL by high-dose statin can provide additional clinical benefit.After the study is completed, we will have categorical evidence on the optimal statin dose and target LDL-C level for secondary prevention in Japanese patients.

  12. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano

    Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has mademore » piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.« less

  13. Twenty First Century Cyberbullying Defined: An Analysis of Intent, Repetition and Emotional Response

    ERIC Educational Resources Information Center

    Walker, Carol Marie

    2012-01-01

    The purpose of this study was to analyze the extent and impact that cyberbullying has on the undergraduate college student and provide a current definition for the event. A priori power analysis guided this research to provide an 80 percent probability of detecting a real effect with medium effect size. Adequate research power was essential to…

  14. Engineering analysis of LANDSAT 1 data for Southeast Asian agriculture

    NASA Technical Reports Server (NTRS)

    Mcnair, A. J.; Heydt, H. L.; Liang, T.; Levine, G. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. LANDSAT spatial resolution was estimated to be adequate, but barely so, for the purpose of detailed assessment of rice or site status. This was due to the spatially fine grain, heterogenous nature of most rice areas. Use of two spectral bands of digital data (MSS 5 and MSS 6 or 7) appeared to be adequate for site recognition and gross site status assessment. Spectral/temporal signatures were found to be more powerful than spectra signatures alone and virtually essential for most analyses of rice growth and rice sites in the Philippine environment. Two band, two date signatures were estimated to be adequate for most purposes, although good results were achieved using one band two- or four-date signatures. A radiometric resolution of 64 levels in each band was found adequate for the analyses of LANDSAT digital data for site recognition and gross site or rice growth assessment.

  15. Electrofishing Effort Required to Estimate Biotic Condition in Southern Idaho Rivers

    EPA Science Inventory

    An important issue surrounding biomonitoring in large rivers is the minimum sampling effort required to collect an adequate number of fish for accurate and precise determinations of biotic condition. During the summer of 2002, we sampled 15 randomly selected large-river sites in...

  16. Effect of Overhydration on Time-Trial Swim Performance.

    ERIC Educational Resources Information Center

    Maresh, Carl M.; Bergeron, Michael E.; Kenefick, Robert W.; Castellani, John W.; Hoffman, Jay R.; Armstrong, Lawrence E.

    2001-01-01

    Examined whether moderate overhydration would enhance the performance of otherwise euhydrated collegiate swimmers during two 183-meter time-trial swims held 3 days apart. Participants swam in alternate, randomized euhydrated, and overhydrated states. Results indicated that euhydration before an intense, short-duration swim was adequate for peak…

  17. 25 hydroxy vitamin D is higher when a renal multivitamin is given with cholecalciferol at hemodialysis.

    PubMed

    Subih, Hadil S; Behrens, Janaye; Burt, Brooke; Clement, Louise; Pannell, Rita; Macha, Laura; Spallholz, Julian; Boylan, Mallory

    2016-12-01

    Seventy six hemodialysis (HD) patients were used in a prospective randomized and clinical trial to determine if a multivitamin with vitamin D (cholecalciferol 12,000 IU/week) given during dialysis would improve the vitamin D status of hemodialysis subjects. Subjects were randomly assigned to two groups: 37 subjects were in the renal multivitamin without vitamin D (MV) group and 39 subjects were in a multivitamin route with vitamin D (MVD) group (12,000 IU of cholecalciferol per week). All subjects were given 2 multivitamin tablets at their 3 HD sessions each week for 20 weeks. Serum 25(OH)D, calcium (Ca), and phosphorus (P) levels were evaluated. At baseline, mean serum 25(OH)D were below adequate (<30 ng/mL) in the MV group (23.5±12.2 ng/mL) and in the MVD group (20.8±10.3 ng/mL). A significant increase was seen in serum 25(OH)D levels (37.7±11.4 ng/mL; p<0.001) in the MVD group after vitamin D supplementation with no rise in the MV group value (21.7±11.4 ng/mL; p=0.06). Prior to supplementation, 17.9% of patients in the MVD group had adequate serum 25(OH)D level and post supplementation 76.9% in the MVD group had adequate serum 25(OH)D. In the MV group, 18.9% subjects had adequate serum 25(OH)D levels at baseline with 18.9% having 25(OH)D >30 ng/mL at the end of the study. There were no significant differences in group values for serum Ca and P. The majority of HD subjects given a multivitamin with cholecalciferol at dialysis had improvement in their vitamin D status.

  18. Optimizing prevention of hospital-acquired venous thromboembolism (VTE): prospective validation of a VTE risk assessment model.

    PubMed

    Maynard, Gregory A; Morris, Timothy A; Jenkins, Ian H; Stone, Sarah; Lee, Joshua; Renvall, Marian; Fink, Ed; Schoenhaus, Robert

    2010-01-01

    Hospital-acquired (HA) venous thromboembolism (VTE) is a common source of morbidity/mortality. Prophylactic measures are underutilized. Available risk assessment models/protocols are not prospectively validated. Improve VTE prophylaxis, reduce HA VTE, and prospectively validate a VTE risk-assessment model. Observational design. Academic medical center. Adult inpatients on medical/surgical services. A simple VTE risk assessment linked to a menu of preferred VTE prophylaxis methods, embedded in order sets. Education, audit/feedback, and concurrent identification of nonadherence. Randomly sampled inpatient audits determined the percent of patients with "adequate" VTE prevention. HA VTE cases were identified concurrently via digital imaging system. Interobserver agreement for VTE risk level and judgment of adequate prophylaxis were calculated from 150 random audits. Interobserver agreement with 5 observers was high (kappa score for VTE risk level = 0.81, and for judgment of "adequate" prophylaxis = 0.90). The percent of patients on adequate prophylaxis improved each of the 3 years (58%, 78%, and 93%; P < 0.001) and reached 98% in the last 6 months of 2007; 361 cases of HA VTE occurred over 3 years. Significant reductions for the risk of HA VTE (risk ratio [RR] = 0.69; 95% confidence interval [CI] = 0.47-0.79) and preventable HA VTE (RR = 0.14; 95% CI = 0.06-0.31) occurred. We detected no increase in heparin-induced thrombocytopenia (HIT) or prophylaxis-related bleeding using administrative data/chart review. We prospectively validated a VTE risk-assessment/prevention protocol by demonstrating ease of use, good interobserver agreement, and effectiveness. Improved VTE prophylaxis resulted in a substantial reduction in HA VTE. (c) 2010 Society of Hospital Medicine.

  19. Modeling missing data in knowledge space theory.

    PubMed

    de Chiusole, Debora; Stefanutti, Luca; Anselmi, Pasquale; Robusto, Egidio

    2015-12-01

    Missing data are a well known issue in statistical inference, because some responses may be missing, even when data are collected carefully. The problem that arises in these cases is how to deal with missing data. In this article, the missingness is analyzed in knowledge space theory, and in particular when the basic local independence model (BLIM) is applied to the data. Two extensions of the BLIM to missing data are proposed: The former, called ignorable missing BLIM (IMBLIM), assumes that missing data are missing completely at random; the latter, called missing BLIM (MissBLIM), introduces specific dependencies of the missing data on the knowledge states, thus assuming that the missing data are missing not at random. The IMBLIM and the MissBLIM modeled the missingness in a satisfactory way, in both a simulation study and an empirical application, depending on the process that generates the missingness: If the missing data-generating process is of type missing completely at random, then either IMBLIM or MissBLIM provide adequate fit to the data. However, if the pattern of missingness is functionally dependent upon unobservable features of the data (e.g., missing answers are more likely to be wrong), then only a correctly specified model of the missingness distribution provides an adequate fit to the data. (c) 2015 APA, all rights reserved).

  20. A Production System Version of the Hearsay-II Speech Understanding System

    DTIC Science & Technology

    1978-04-01

    synchronization mechanisms turn out to be adequate with a rull complement of KSs. Finally, HSP is found to aid solution of the Small Address Problem, as it...much greater than that if HSP’s less powerful synchronization mechanisms turn out to be adequate with a full complement of KSs. Finally, HSP is...earlier version of HSII which had a limited set of KSs. With a richer set of KSs and/or a reduction (or elimination) of synchronization overheads, the

  1. Colorado Springs dedicates zero-discharge coal plant. [Ray D. Nixon plant

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hennessy, M.; Zeien, C.T.

    1980-12-01

    The zero-discharge Ray D. Nixon coal-fired power plant was designed to treat and recycle effluents in a region with limited water supplies. The site purchase included groundwater rights and some diversion rights, but a properly-managed local aquifer was determined to be adequate. The closed-loop design recovers 95 percent of the water for reuse. The overall water-management system produces adequate water and treats effluents at less cost and with higher water-quality protection than alternate systems. (DCK)

  2. Effects of transcutaneous electrical nerve stimulation (TENS) on arterial stiffness and blood pressure in resistant hypertensive individuals: study protocol for a randomized controlled trial.

    PubMed

    Vilela-Martin, José Fernando; Giollo-Junior, Luiz Tadeu; Chiappa, Gaspar Rogério; Cipriano-Junior, Gerson; Vieira, Paulo José Cardoso; dos Santos Ricardi, Fábio; Paz-Landim, Manoel Ildefonso; de Andrade, Days Oliveira; Cestário, Elizabeth do Espírito Santo; Cosenso-Martin, Luciana Neves; Yugar-Toledo, Juan Carlos; Cipullo, José Paulo

    2016-03-29

    Resistant hypertension (RH) treatment requires an adequate and intense therapeutic approach. However, the results are not always satisfactory despite intensive treatment. Of the different pathophysiological mechanisms involved in the pathogenesis of RH, sympathetic overstimulation and therapies that block the sympathetic system have been widely studied. These approaches, however, are invasive and expensive. Another possible approach is by transcutaneous electrical nerve stimulation (TENS), a noninvasive method that modulates activity by using low-frequency transcutaneous electrical stimulation to inhibit primary afferent pathways. Thus, the current study will evaluate the effect of applying TENS in the cervicothoracic region of subjects with RH and will seek to develop a new low-cost and readily available therapy to treat this group of hypertensive individuals. This is a randomized, single blind (subject), parallel-assignment study controlled with a sham group and including participants aged 40 to 70 years with resistant hypertension. The trial has two arms: the treatment and control (sham group). The treatment group will be submitted to the stimulation procedure (TENS). The sham group will not be submitted to stimulation. The primary outcomes will be a reduction in the peripheral blood pressure and adverse events. The secondary outcomes will be a reduction the central blood pressure. The study will last 30 days. The sample size was calculated assuming an alpha error of 5 % to reject the null hypothesis with a statistical power of 80 %, thereby resulting in 28 participants per group (intervention versus sham). In recent decades, RH has become very common and costly. Adequate control requires several drugs, and in many cases, treatment is not successful. Sympathetic nervous system inhibition by renal denervation and central inhibition have significant effects in reducing BP; however, these treatments are costly and invasive. Another type of sympathetic nervous system inhibition can also be noninvasively achieved by electric current. Therefore, the application of TENS may be a new therapeutic option for treating resistant hypertensive individuals. Clinical Trials NCT02365974.

  3. The electronic stopping powers and angular energy-loss dependence of helium and lithium ions in the silicon crystal

    NASA Astrophysics Data System (ADS)

    Mikšová, R.; Macková, A.; Malinský, P.

    2017-09-01

    We have measured the electronic stopping powers of helium and lithium ions in the channelling direction of the Si〈1 0 0〉 crystal. The energy range used (2.0-8.0 MeV) was changed by 200 and 400-keV steps. The ratio α between the channelling and random stopping powers was determined as a function of the angle for 2, 3 and 4 MeV 4He+ ions and for 3 and 6 MeV 7Li+,2+ ions. The measurements were carried out using the Rutherford backscattering spectrometry in the channelling mode (RBS-C) in a silicon-on-insulator material. The experimental channelling stopping-power values measured in the channelling direction were then discussed in the frame of the random energy stopping predictions calculated using SRIM-2013 code and the theoretical unitary convolution approximation (UCA) model. The experimental channelling stopping-power values decrease with increasing ion energy. The stopping-power difference between channelled and randomly moving ions increases with the enhanced initial ion energy. The ratio between the channelling and random ion stopping powers α as a function of the ion beam incoming angle for 2, 3 and 4 MeV He+ ions and for 3 and 6 MeV Li+,2+ ions was observed in the range 0.5-1.

  4. Solar power satellite system definition study. Part 2, volume 4: Microwave power transmission systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A slotted waveguide planar array was established as the baseline design for the spaceborne transmitter antenna. Key aspects of efficient energy conversion at both ends of the power transfer link were analyzed and optimized alternate approaches in the areas of antenna and tube design are discussed. An integrated design concept was developed which meets design requirements, observes structural and thermal constraints, exhibits good performance and was developed in adequate depth to permit cost estimating at the subsystem/component level.

  5. PERSONAL RADIATION MONITOR

    DOEpatents

    Dilworth, R.H.; Borkowski, C.J.

    1961-12-26

    A transistorized, fountain pen type radiation monitor to be worn on the person is described. Radiation produces both light flashes in a small bulb and an audible warning tone, the frequency of both the tone and light flashes being proportional to radiation intensity. The device is powered by a battery and a blocking oscillator step-up power supply The oscillator frequency- is regulated to be proportional to the radiation intensity, to provide adequate power in high radiation fields, yet minimize battery drain at low operating intensities. (AEC)

  6. 14 CFR 25.1143 - Engine controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... means of controlling its engine. (d) For each fluid injection (other than fuel) system and its controls... injection fluid is adequately controlled. (e) If a power or thrust control incorporates a fuel shutoff...

  7. 14 CFR 25.1143 - Engine controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... means of controlling its engine. (d) For each fluid injection (other than fuel) system and its controls... injection fluid is adequately controlled. (e) If a power or thrust control incorporates a fuel shutoff...

  8. Survival distributions impact the power of randomized placebo-phase design and parallel groups randomized clinical trials.

    PubMed

    Abrahamyan, Lusine; Li, Chuan Silvia; Beyene, Joseph; Willan, Andrew R; Feldman, Brian M

    2011-03-01

    The study evaluated the power of the randomized placebo-phase design (RPPD)-a new design of randomized clinical trials (RCTs), compared with the traditional parallel groups design, assuming various response time distributions. In the RPPD, at some point, all subjects receive the experimental therapy, and the exposure to placebo is for only a short fixed period of time. For the study, an object-oriented simulation program was written in R. The power of the simulated trials was evaluated using six scenarios, where the treatment response times followed the exponential, Weibull, or lognormal distributions. The median response time was assumed to be 355 days for the placebo and 42 days for the experimental drug. Based on the simulation results, the sample size requirements to achieve the same level of power were different under different response time to treatment distributions. The scenario where the response times followed the exponential distribution had the highest sample size requirement. In most scenarios, the parallel groups RCT had higher power compared with the RPPD. The sample size requirement varies depending on the underlying hazard distribution. The RPPD requires more subjects to achieve a similar power to the parallel groups design. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Analysis of the power flow in nonlinear oscillators driven by random excitation using the first Wiener kernel

    NASA Astrophysics Data System (ADS)

    Hawes, D. H.; Langley, R. S.

    2018-01-01

    Random excitation of mechanical systems occurs in a wide variety of structures and, in some applications, calculation of the power dissipated by such a system will be of interest. In this paper, using the Wiener series, a general methodology is developed for calculating the power dissipated by a general nonlinear multi-degree-of freedom oscillatory system excited by random Gaussian base motion of any spectrum. The Wiener series method is most commonly applied to systems with white noise inputs, but can be extended to encompass a general non-white input. From the extended series a simple expression for the power dissipated can be derived in terms of the first term, or kernel, of the series and the spectrum of the input. Calculation of the first kernel can be performed either via numerical simulations or from experimental data and a useful property of the kernel, namely that the integral over its frequency domain representation is proportional to the oscillating mass, is derived. The resulting equations offer a simple conceptual analysis of the power flow in nonlinear randomly excited systems and hence assist the design of any system where power dissipation is a consideration. The results are validated both numerically and experimentally using a base-excited cantilever beam with a nonlinear restoring force produced by magnets.

  10. Implantable radio frequency identification sensors: wireless power and communication.

    PubMed

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

  11. A systematic review and meta-analysis of randomized controlled trials of adjunctive ketamine in electroconvulsive therapy: efficacy and tolerability.

    PubMed

    McGirr, Alexander; Berlim, Marcelo T; Bond, David J; Neufeld, Nicholas H; Chan, Peter Y; Yatham, Lakshmi N; Lam, Raymond W

    2015-03-01

    Electroconvulsive therapy (ECT) remains one of the most effective tools in the psychiatric treatment armamentarium, particularly for refractory depression. Yet, there remains a subset of patients who do not respond to ECT or for whom clinically adequate seizures cannot be elicited, for whom ketamine has emerged as a putative augmentation agent. We searched EMBASE, PsycINFO, CENTRAL, and MEDLINE from 1962 to April 2014 to identify randomized controlled trials evaluating ketamine in ECT (PROSPERO #CRD42014009035). Clinical remission, response, and change in depressive symptom scores were extracted by two independent raters. Adverse events were recorded. Drop-outs were assessed as a proxy for acceptability. Meta-analyses employed a random effects model. Data were synthesized from 5 RCTs, representing a total of 182 patients with major depressive episodes (n = 165 Major Depressive Disorder, n = 17 Bipolar Disorder). ECT with ketamine augmentation was not associated with higher rates of clinical remission (Risk Difference (RD) = 0.00; 95%CI = -0.08 to 0.10), response (RD = -0.01; 95%CI = -0.11 to 0.08), or improvements in depressive symptoms (SMD = 0.38; 95%CI = -0.41 to 1.17). Ketamine augmentation was associated with higher rates of confusion/disorientation/prolonged delirium (OR = 6.59, 95%CI: 1.28-33.82, NNH = 3), but not agitation, hypertension or affective switches. Our meta-analysis of randomized controlled trials of ketamine augmentation in the ECT setting suggests a lack of clinical efficacy, and an increased likelihood of confusion. Individuals for whom adequate seizures or therapeutic response cannot be obtained have not been studied using randomized controlled designs. Additional research is required to address the role of ketamine in this population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 76 FR 30819 - Special Conditions: Turbomeca Arriel 2D Turboshaft Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ... power for search and rescue missions. The applicable airworthiness regulations do not contain adequate... rating. This rating was requested by the applicant to support rotorcraft search and rescue missions that...

  13. Role of phenotypic and genetic testing in managing clopidogrel therapy.

    PubMed

    Chan, Noel C; Eikelboom, John W; Ginsberg, Jeffrey S; Lauw, Mandy N; Vanassche, Thomas; Weitz, Jeffrey I; Hirsh, Jack

    2014-07-31

    The P2Y12 inhibitors, clopidogrel, prasugrel, and ticagrelor, are administered in fixed doses without laboratory monitoring. Randomized trials in acute coronary syndrome have shown that prasugrel and ticagrelor are more effective than standard-dose clopidogrel. Nonetheless, standard-dose clopidogrel remains widely used because it causes less bleeding and is less expensive. Patients treated with standard-dose clopidogrel have substantial variability in platelet inhibition, which is partly explained by genetic polymorphisms encoding CYP2C19, the hepatic enzyme involved in biotransformation of clopidogrel to its active metabolite. Some advocate tailoring P2Y12 inhibitor therapy according to the results of routine laboratory testing. Although there is good evidence for analytic, biological, and clinical validity of several phenotypic and genotypic biomarkers, the benefit of a management strategy that incorporates routine biomarker testing over standard of care without such testing remains unproven. Appropriately designed, adequately powered trials are needed but face the challenges of feasibility, cost, and the progressive switch from clopidogrel to prasugrel or ticagrelor. © 2014 by The American Society of Hematology.

  14. Faith-Based Institutions as Venues for Obesity Prevention.

    PubMed

    Maynard, Maria J

    2017-06-01

    The aim of this current narrative review is to critique the scope and value of recent studies with a focus on obesity-related health promotion in faith organizations. Electronic database searches, scanning of the reference lists of identified articles, and hand searching of journals for articles written in English and published in 2013-2016 revealed 16 studies. Half of the studies involved African-Americans, in churches and with predominantly female participants. Research among other ethnic groups was more likely to be exploratory. All of the 11 studies reporting the impact of programmes on weight-related measures showed favourable outcomes. However, due to study limitations (small sample size, short duration, attrition), significant unbiased effects cannot yet be concluded for most of the interventions reviewed. Study strengths included application of theory in community engagement and detailed description of cultural tailoring. Faith organizations show promise as settings for obesity prevention among high-risk groups, particularly African-Americans. Support for progressing formative work to adequately powered, randomized controlled trials is vital. Wider involvement of diverse faith settings and targeting obesity in men and childhood would be valuable developments.

  15. Scaled Brownian motion: a paradoxical process with a time dependent diffusivity for the description of anomalous diffusion.

    PubMed

    Jeon, Jae-Hyung; Chechkin, Aleksei V; Metzler, Ralf

    2014-08-14

    Anomalous diffusion is frequently described by scaled Brownian motion (SBM), a Gaussian process with a power-law time dependent diffusion coefficient. Its mean squared displacement is 〈x(2)(t)〉 ≃ 2K(t)t with K(t) ≃ t(α-1) for 0 < α < 2. SBM may provide a seemingly adequate description in the case of unbounded diffusion, for which its probability density function coincides with that of fractional Brownian motion. Here we show that free SBM is weakly non-ergodic but does not exhibit a significant amplitude scatter of the time averaged mean squared displacement. More severely, we demonstrate that under confinement, the dynamics encoded by SBM is fundamentally different from both fractional Brownian motion and continuous time random walks. SBM is highly non-stationary and cannot provide a physical description for particles in a thermalised stationary system. Our findings have direct impact on the modelling of single particle tracking experiments, in particular, under confinement inside cellular compartments or when optical tweezers tracking methods are used.

  16. Pharmacotherapy for thyroid nodules. A systematic review and meta-analysis.

    PubMed

    Richter, Bernd; Neises, Gudrun; Clar, Christine

    2002-09-01

    The review highlights the uncertainty in the management of nodular thyroid disease. Thyroxine suppressive treatment is given in the hope that nodules might decrease in size, sometimes assuming that dependency on TSH is different in benign and malignant nodular disease. Follow-up of benign nodules over 10 years suggested that most remain the same, shrink, or disappear [14]. TSH suppression may lead to hyperthyroidism, reduced bone density [37.39], and atrial fibrilation; however, apart from reduction of nodule size or arrest in nodule growth, thyroxine therapy may benefit patients by reducing perinodular volume. Consequently, both pressure symptoms and cosmetic complaints could improve. Unfortunately, no information concerning symptoms or well-being is available from published randomized trials. In conclusion, more high quality studies of sufficient duration with adequate power estimation are needed. Uncertainty about predictors of response or the impact on outcomes that are important to patients leaves considerable doubt about the wisdom of applying suppressive therapy. Future studies shoudl include patient-important outcomes including thyroid cancer incidence, health-related quality of life and costs.

  17. Distribution of Candida albicans genotypes among family members

    NASA Technical Reports Server (NTRS)

    Mehta, S. K.; Stevens, D. A.; Mishra, S. K.; Feroze, F.; Pierson, D. L.

    1999-01-01

    Thirty-three families (71 subjects) were screened for the presence of Candida albicans in mouthwash or stool specimens; 12 families (28 subjects) were culture-positive for this yeast. An enrichment procedure provided a twofold increase in the recovery of C. albicans from mouthwash specimens. Nine of the twelve culture-positive families had two positive members each, two families had three positive members each, and one family had four positive members. Genetic profiles were obtained by three methods: pulsed-field gel electrophoresis; restriction endonuclease analysis, and random amplification of polymorphic DNA analysis. DNA fingerprinting of C. albicans isolated from one body site three consecutive times revealed that each of the 12 families carried a distinct genotype. No two families shared the same strain, and two or more members of a family commonly shared the same strain. Intrafamily genotypic identity (i.e., each member within the family harbored the same strain) was demonstrated in six families. Genotypes of isolates from husband and wife differed from one another in five families. All three methods were satisfactory in determining genotypes; however, we concluded that restriction endonuclease analysis provided adequate resolving power.

  18. Aura interruption: the Andrews/Reiter behavioral intervention may reduce seizures and improve quality of life - a pilot trial.

    PubMed

    Elsas, S M; Gregory, W L; White, G; Navarro, G; Salinsky, M C; Andrews, D J

    2011-12-01

    Patients with epilepsy frequently experience depression and emotional stress and these may function as seizure triggers in epileptogenic frontotemporal cortex, which serves in emotional processing. Eight patients enrolled in a pilot trial of a 6-month epilepsy-specific behavioral approach comprising counseling and relaxation to recognize and eliminate emotional seizure triggers. Potential participants with psychogenic seizures were excluded by long-term EEG and/or the MMPI profile. One participant became seizure free, another had an approximately 90% reduction in seizures, and two additional participants achieved a greater than 50% reduction in seizure frequency (total responder rate=50%), stable during 6 months of observation after the intervention. All completers showed marked and stable improvement of quality of life (Quality of Life in Epilepsy-89 inventory) and temporary improvement in the Profile of Mood States. An adequately powered randomized controlled trial is needed to confirm our findings, which suggest that behavioral approaches may hold promise for motivated patients with epilepsy. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Painful ejaculation.

    PubMed

    Ilie, Cristian P; Mischianu, Dan L; Pemberton, Richard J

    2007-06-01

    We reviewed previous publications on post-orgasmic pain with reference to prevalence, epidemiology and treatment options, using the Ovid and PubMed (updated May 2006) databases to comprehensively search MEDLINE for reports on post-orgasmic pain that included peer-reviewed English-language articles. Official proceedings of internationally known scientific societies were also assessed. Because of the heterogeneity of the studies we did not apply meta- analytic techniques to the data. The incidence of post-orgasmic pain is 1-9.7%. The ejaculatory pain is associated with prostatitis, chronic pelvic pain syndrome, benign prostatic hyperplasia, and ejaculatory duct obstruction; it is also described in patients after procedures like radical prostatectomy. Aetiopathogenic theories include those referring to bladder neck closure and pudendal neuropathy. The treatment options vary from self-care, a 'perineal hyperprotection programme' to medication with the alpha-blocker, topiramate, and even surgical procedures like removing a section of the sacrotuberous ligament, neurolysis of the pudendal nerve or removing a section of the sacrospinous ligament. This is the first update of the subject, with reference to prevalence, epidemiology and treatment options. There is a need for adequately powered, prospective randomized trials on aetiology and treatment options.

  20. Empirically Exploring Higher Education Cultures of Assessment

    ERIC Educational Resources Information Center

    Fuller, Matthew B.; Skidmore, Susan T.; Bustamante, Rebecca M.; Holzweiss, Peggy C.

    2016-01-01

    Although touted as beneficial to student learning, cultures of assessment have not been examined adequately using validated instruments. Using data collected from a stratified, random sample (N = 370) of U.S. institutional research and assessment directors, the models tested in this study provide empirical support for the value of using the…

  1. A Bayesian Nonparametric Meta-Analysis Model

    ERIC Educational Resources Information Center

    Karabatsos, George; Talbott, Elizabeth; Walker, Stephen G.

    2015-01-01

    In a meta-analysis, it is important to specify a model that adequately describes the effect-size distribution of the underlying population of studies. The conventional normal fixed-effect and normal random-effects models assume a normal effect-size population distribution, conditionally on parameters and covariates. For estimating the mean overall…

  2. APPLICATION OF A MULTIPURPOSE UNEQUAL-PROBABILITY STREAM SURVEY IN THE MID-ATLANTIC COASTAL PLAIN

    EPA Science Inventory

    A stratified random sample with unequal-probability selection was used to design a multipurpose survey of headwater streams in the Mid-Atlantic Coastal Plain. Objectives for data from the survey include unbiased estimates of regional stream conditions, and adequate coverage of un...

  3. Electrical Prototype Power Processor for the 30-cm Mercury electric propulsion engine

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Frye, R. J.

    1978-01-01

    An Electrical Prototpye Power Processor has been designed to the latest electrical and performance requirements for a flight-type 30-cm ion engine and includes all the necessary power, command, telemetry and control interfaces for a typical electric propulsion subsystem. The power processor was configured into seven separate mechanical modules that would allow subassembly fabrication, test and integration into a complete power processor unit assembly. The conceptual mechanical packaging of the electrical prototype power processor unit demonstrated the relative location of power, high voltage and control electronic components to minimize electrical interactions and to provide adequate thermal control in a vacuum environment. Thermal control was accomplished with a heat pipe simulator attached to the base of the modules.

  4. Impact of communities, health, and emotional-related factors on smoking use: comparison of joint modeling of mean and dispersion and Bayes' hierarchical models on add health survey.

    PubMed

    Pu, Jie; Fang, Di; Wilson, Jeffrey R

    2017-02-03

    The analysis of correlated binary data is commonly addressed through the use of conditional models with random effects included in the systematic component as opposed to generalized estimating equations (GEE) models that addressed the random component. Since the joint distribution of the observations is usually unknown, the conditional distribution is a natural approach. Our objective was to compare the fit of different binary models for correlated data in Tabaco use. We advocate that the joint modeling of the mean and dispersion may be at times just as adequate. We assessed the ability of these models to account for the intraclass correlation. In so doing, we concentrated on fitting logistic regression models to address smoking behaviors. Frequentist and Bayes' hierarchical models were used to predict conditional probabilities, and the joint modeling (GLM and GAM) models were used to predict marginal probabilities. These models were fitted to National Longitudinal Study of Adolescent to Adult Health (Add Health) data for Tabaco use. We found that people were less likely to smoke if they had higher income, high school or higher education and religious. Individuals were more likely to smoke if they had abused drug or alcohol, spent more time on TV and video games, and been arrested. Moreover, individuals who drank alcohol early in life were more likely to be a regular smoker. Children who experienced mistreatment from their parents were more likely to use Tabaco regularly. The joint modeling of the mean and dispersion models offered a flexible and meaningful method of addressing the intraclass correlation. They do not require one to identify random effects nor distinguish from one level of the hierarchy to the other. Moreover, once one can identify the significant random effects, one can obtain similar results to the random coefficient models. We found that the set of marginal models accounting for extravariation through the additional dispersion submodel produced similar results with regards to inferences and predictions. Moreover, both marginal and conditional models demonstrated similar predictive power.

  5. Multi-field inflation with a random potential

    NASA Astrophysics Data System (ADS)

    Tye, S.-H. Henry; Xu, Jiajun; Zhang, Yang

    2009-04-01

    Motivated by the possibility of inflation in the cosmic landscape, which may be approximated by a complicated potential, we study the density perturbations in multi-field inflation with a random potential. The random potential causes the inflaton to undergo a Brownian-like motion with a drift in the D-dimensional field space, allowing entropic perturbation modes to continuously and randomly feed into the adiabatic mode. To quantify such an effect, we employ a stochastic approach to evaluate the two-point and three-point functions of primordial perturbations. We find that in the weakly random scenario where the stochastic scatterings are frequent but mild, the resulting power spectrum resembles that of the single field slow-roll case, with up to 2% more red tilt. The strongly random scenario, in which the coarse-grained motion of the inflaton is significantly slowed down by the scatterings, leads to rich phenomenologies. The power spectrum exhibits primordial fluctuations on all angular scales. Such features may already be hiding in the error bars of observed CMB TT (as well as TE and EE) power spectrum and have been smoothed out by binning of data points. With more data coming in the future, we expect these features can be detected or falsified. On the other hand the tensor power spectrum itself is free of fluctuations and the tensor to scalar ratio is enhanced by the large ratio of the Brownian-like motion speed over the drift speed. In addition a large negative running of the power spectral index is possible. Non-Gaussianity is generically suppressed by the growth of adiabatic perturbations on super-horizon scales, and is negligible in the weakly random scenario. However, non-Gaussianity can possibly be enhanced by resonant effects in the strongly random scenario or arise from the entropic perturbations during the onset of (p)reheating if the background inflaton trajectory exhibits particular properties. The formalism developed in this paper can be applied to a wide class of multi-field inflation models including, e.g. the N-flation scenario.

  6. Powered lower limb orthoses for gait rehabilitation

    PubMed Central

    Ferris, Daniel P.; Sawicki, Gregory S.; Domingo, Antoinette

    2006-01-01

    Bodyweight supported treadmill training has become a prominent gait rehabilitation method in leading rehabilitation centers. This type of locomotor training has many functional benefits but the labor costs are considerable. To reduce therapist effort, several groups have developed large robotic devices for assisting treadmill stepping. A complementary approach that has not been adequately explored is to use powered lower limb orthoses for locomotor training. Recent advances in robotic technology have made lightweight powered orthoses feasible and practical. An advantage to using powered orthoses as rehabilitation aids is they allow practice starting, turning, stopping, and avoiding obstacles during overground walking. PMID:16568153

  7. Combined Effect of Random Transmit Power Control and Inter-Path Interference Cancellation on DS-CDMA Packet Mobile Communications

    NASA Astrophysics Data System (ADS)

    Kudoh, Eisuke; Ito, Haruki; Wang, Zhisen; Adachi, Fumiyuki

    In mobile communication systems, high speed packet data services are demanded. In the high speed data transmission, throughput degrades severely due to severe inter-path interference (IPI). Recently, we proposed a random transmit power control (TPC) to increase the uplink throughput of DS-CDMA packet mobile communications. In this paper, we apply IPI cancellation in addition to the random TPC. We derive the numerical expression of the received signal-to-interference plus noise power ratio (SINR) and introduce IPI cancellation factor. We also derive the numerical expression of system throughput when IPI is cancelled ideally to compare with the Monte Carlo numerically evaluated system throughput. Then we evaluate, by Monte-Carlo numerical computation method, the combined effect of random TPC and IPI cancellation on the uplink throughput of DS-CDMA packet mobile communications.

  8. Log N-log S in inconclusive

    NASA Technical Reports Server (NTRS)

    Klebesadel, R. W.; Fenimore, E. E.; Laros, J.

    1983-01-01

    The log N-log S data acquired by the Pioneer Venus Orbiter Gamma Burst Detector (PVO) are presented and compared to similar data from the Soviet KONUS experiment. Although the PVO data are consistent with and suggestive of a -3/2 power law distribution, the results are not adequate at this state of observations to differentiate between a -3/2 and a -1 power law slope.

  9. Solar- and wind-powered irrigation systems

    NASA Astrophysics Data System (ADS)

    Enochian, R. V.

    1982-02-01

    Five different direct solar and wind energy systems are technically feasible for powering irrigation pumps. However, with projected rates of fossil fuel costs, only two may produce significant unsubsidied energy for irrigation pumping before the turn of the century. These are photovoltaic systems with nonconcentrating collectors (providing that projected costs of manufacturing solar cells prove correct); and wind systems, especially in remote areas where adequate wind is available.

  10. Fast physical-random number generation using laser diode's frequency noise: influence of frequency discriminator

    NASA Astrophysics Data System (ADS)

    Matsumoto, Kouhei; Kasuya, Yuki; Yumoto, Mitsuki; Arai, Hideaki; Sato, Takashi; Sakamoto, Shuichi; Ohkawa, Masashi; Ohdaira, Yasuo

    2018-02-01

    Not so long ago, pseudo random numbers generated by numerical formulae were considered to be adequate for encrypting important data-files, because of the time needed to decode them. With today's ultra high-speed processors, however, this is no longer true. So, in order to thwart ever-more advanced attempts to breach our system's protections, cryptologists have devised a method that is considered to be virtually impossible to decode, and uses what is a limitless number of physical random numbers. This research describes a method, whereby laser diode's frequency noise generate a large quantities of physical random numbers. Using two types of photo detectors (APD and PIN-PD), we tested the abilities of two types of lasers (FP-LD and VCSEL) to generate random numbers. In all instances, an etalon served as frequency discriminator, the examination pass rates were determined using NIST FIPS140-2 test at each bit, and the Random Number Generation (RNG) speed was noted.

  11. Estimating rate uncertainty with maximum likelihood: differences between power-law and flicker–random-walk models

    USGS Publications Warehouse

    Langbein, John O.

    2012-01-01

    Recent studies have documented that global positioning system (GPS) time series of position estimates have temporal correlations which have been modeled as a combination of power-law and white noise processes. When estimating quantities such as a constant rate from GPS time series data, the estimated uncertainties on these quantities are more realistic when using a noise model that includes temporal correlations than simply assuming temporally uncorrelated noise. However, the choice of the specific representation of correlated noise can affect the estimate of uncertainty. For many GPS time series, the background noise can be represented by either: (1) a sum of flicker and random-walk noise or, (2) as a power-law noise model that represents an average of the flicker and random-walk noise. For instance, if the underlying noise model is a combination of flicker and random-walk noise, then incorrectly choosing the power-law model could underestimate the rate uncertainty by a factor of two. Distinguishing between the two alternate noise models is difficult since the flicker component can dominate the assessment of the noise properties because it is spread over a significant portion of the measurable frequency band. But, although not necessarily detectable, the random-walk component can be a major constituent of the estimated rate uncertainty. None the less, it is possible to determine the upper bound on the random-walk noise.

  12. Probabilistic Density Function Method for Stochastic ODEs of Power Systems with Uncertain Power Input

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Peng; Barajas-Solano, David A.; Constantinescu, Emil

    Wind and solar power generators are commonly described by a system of stochastic ordinary differential equations (SODEs) where random input parameters represent uncertainty in wind and solar energy. The existing methods for SODEs are mostly limited to delta-correlated random parameters (white noise). Here we use the Probability Density Function (PDF) method for deriving a closed-form deterministic partial differential equation (PDE) for the joint probability density function of the SODEs describing a power generator with time-correlated power input. The resulting PDE is solved numerically. A good agreement with Monte Carlo Simulations shows accuracy of the PDF method.

  13. Can exergaming contribute to improving physical activity levels and health outcomes in children?

    PubMed

    Daley, Amanda J

    2009-08-01

    Physical inactivity among children is a serious public health problem. It has been suggested that high levels of screen time are contributory factors that encourage sedentary lifestyles in young people. As physical inactivity and obesity levels continue to rise in young people, it has been proposed that new-generation active computer- and video-console games (otherwise known as "exergaming") may offer the opportunity to contribute to young people's energy expenditure during their free time. Although studies have produced some encouraging results regarding the energy costs involved in playing active video-console games, the energy costs of playing the authentic versions of activity-based video games are substantially larger, highlighting that active gaming is no substitute for real sports and activities. A small number of exergaming activities engage children in moderate-intensity activity, but most do not. Only 3 very small trials have considered the effects of exergaming on physical activity levels and/or other health outcomes in children. Evidence from these trials has been mixed; positive trends for improvements in some health outcomes in the intervention groups were noted in 2 trials. No adequately powered randomized, controlled trial has been published to date, and no trial has assessed the long-term impact of exergaming on children's health. We now need high-quality randomized, controlled trials to evaluate the effectiveness and sustainability of exergaming, as well as its clinical relevance; until such studies take place, we should remain cautious about its ability to positively affect children's health.

  14. Augmenting Prolonged Exposure therapy for PTSD with intranasal oxytocin: A randomized, placebo-controlled pilot trial.

    PubMed

    Flanagan, Julianne C; Sippel, Lauren M; Wahlquist, Amy; Moran-Santa Maria, Megan M; Back, Sudie E

    2018-03-01

    Posttraumatic stress disorder (PTSD) is a chronic, debilitating condition for which Prolonged Exposure (PE) therapy is highly efficacious. However, for some individuals, premature dropout and residual PTSD symptoms remain obstacles. The neuropeptide oxytocin is a promising candidate to enhance PE due to its ability to enhance 1) prosocial cognition and behavior, which are theorized to promote positive working alliance, and 2) extinction learning, which is the central mechanism of action underlying successful PE treatment. Despite a robust theoretical rationale, no studies to date have combined evidence-based psychotherapy for PTSD with oxytocin. This randomized, placebo-controlled, double-blind pilot trial examined the feasibility, safety, and preliminary efficacy of augmenting PE with oxytocin. Participants were 17 individuals with diverse index traumas. Participants self-administered intranasal oxytocin (40 IU) or matching placebo 45 min prior to each weekly PE therapy session. One adverse event occurred in the placebo group and three individuals dropped out (17.6%; 2 oxytocin group and 1 placebo group). The oxytocin group demonstrated lower PTSD and depression symptoms during PE, and had higher working alliance scores, although these differences did not reach statistical significance. Although preliminary, the findings support the feasibility of oxytocin combined with PE. Adequately powered studies are necessary to determine whether oxytocin enhances PE treatment outcomes and to examine potential mechanisms, such as accelerating extinction learning, enhancing early response, and preventing premature dropout. NCT03238924. Copyright © 2017. Published by Elsevier Ltd.

  15. Albumin administration for fluid resuscitation in burn patients: A systematic review and meta-analysis.

    PubMed

    Eljaiek, Roberto; Heylbroeck, Christophe; Dubois, Marc-Jacques

    2017-02-01

    The objective was to systematically review the literature summarizing the effect on mortality of albumin compared to non-albumin solutions during the fluid resuscitation phase of burn injured patients. We searched MEDLINE, EMBASE and CENTRAL and the content of two leading journals in burn care, Burns and Journal of Burn Care and Research. Two reviewers independently selected randomized controlled trials comparing albumin vs. non-albumin solutions for the acute resuscitation of patients with >20% body surface area involvement. Reviewers abstracted data independently and assessed methodological quality of the included trials using predefined criteria. A random effects model was used to assess mortality. We identified 164 trials of which, 4 trials involving 140 patients met our inclusion criteria. Overall, the methodological quality of the included trials was fair. We did not find a significant benefit of albumin solutions as resuscitation fluid on mortality in burn patients (relative risk (RR) 1.6; 95% confidence interval (CI), 0.63-4.08). Total volume of fluid infusion during the phase of resuscitation was lower in patients receiving albumin containing solution -1.00ml/kg/%TBSA (total body surface area) (95% CI, -1.42 to -0.58). The pooled estimate demonstrated a neutral effect on mortality in burn patients resuscitated acutely with albumin solutions. Due to limited evidence and uncertainty, an adequately powered, high quality trial could be required to assess the impact of albumin solutions on mortality in burn patients. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  16. Effects of levosimendan on mortality in patients undergoing cardiac surgery: A systematic review and meta-analysis.

    PubMed

    Chen, Peili; Wu, Xiaoqiang; Wang, Zhiwei; Li, Zhenya; Tian, Xiangyong; Wang, Junpeng; Yan, Tianzhong

    2018-06-01

    We sought to determine the impact of levosimendan on mortality following cardiac surgery based on large-scale randomized controlled trials (RCTs). We searched PubMed, Web of Science, Cochrane databases, and ClinicalTrials.gov for RCTs published up to December 2017, on levosimendan for patients undergoing cardiac surgery. A total of 25 RCTs enrolling 2960 patients met the inclusion criteria; data from 15 placebo-controlled randomized trials were included for meta-analysis. Pooled analysis showed that the all-cause mortality rate was 6.4% (71 of 1106) in the levosimendan group and 8.4% (93 of 1108) in the placebo group (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.55-1.04; P = 0.09). There were no significant differences between the two groups in the rates of myocardial infarction (OR: 0.91; 95% CI, 0.68-1.21; P = 0.52), serious adverse events (OR: 0.84; 95% CI, 0.66-1.07; P = 0.17), hypotension (OR: 1.69; 95% CI, 0.94-3.03; P = 0.08), and low cardiac output syndrome (OR: 0.47; 95% CI, 0.22-1.02; P = 0.05). Levosimendan did not result in a reduction in mortality in adult cardiac surgery patients. Well designed, adequately powered, multicenter trials are necessary to determine the role of levosimendan in adult cardiac surgery. © 2018 The Authors. Journal of Cardiac Surgery Published by Wiley Periodicals Inc.

  17. The effect of vitamin A on renal damage following acute pyelonephritis in children: a meta-analysis of randomized controlled trials.

    PubMed

    Zhang, Guo-Qiang; Chen, Jin-Liang; Zhao, Yong

    2016-03-01

    Renal scarring after acute pyelonephritis (APN) in children is of concern and in the worst cases leads to long-term cardiovascular morbidity. There are reports that vitamin A may alleviate renal damage following APN. We conducted a meta-analysis to investigate the role of vitamin A in the alleviation of renal damage. We searched PubMed, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, the Cochrane Library) and the Wang Fang database (Chinese) from their inception to February 3, 2015 for randomized controlled trials (RCTs) investigating vitamin A and renal damage. Primary outcome was number of patients/kidneys with renal damage, defined as persistence of photopenic lesions based on technetium-99m dimercaptosuccinic acid renal scintigraphy. We calculated pooled relative risks for renal damage in the vitamin A group. Four RCTs, involving a total of 248 patients aged 1-144 months (120 in experimental group, 128 in control group), were included in the meta-analysis. Vitamin A was inversely associated with renal damage (relative risk 0.53, 95 % confidence interval 0.43, 0.67) when compared with placebo group after an average follow-up of 5 months. Current evidence indicates that vitamin A may exert a preventive effect on renal damage in children with APN. However, this finding largely relies on a few studies of low methodological quality, i.e., high risk of selection bias, performance bias and attrition bias. Hence, high-quality and adequately powered RCTs are warranted.

  18. Selenium and glutamine supplements: where are we heading? A critical care perspective.

    PubMed

    Andrews, Peter J D

    2010-03-01

    There is considerable interest in glutamine and selenium in critical care as both offer the potential to enhance host defences, through different but complimentary mechanisms and may reduce subsequent infections and mortality. The SIGNET trial (randomized controlled factorial trial) is the largest, critical care study of both supplements. The data have been presented publicly, but the data are not published or available for review and will therefore not be discussed fully in this update. In the present review I will explore the recently available (past 1-2 years) published literature. The current literature demonstrates that there are currently insufficient data to enable confident recommendations on the optimal route, timing, duration and dosage of each of these nutritional supplements. The pending results of SIGNET, the largest critical care trial of parenteral nutrition supplemented by glutamine and or selenium promises to clarify some of the current ambiguities and inform future practice. To be able to confidently establish or refute the hypothesis that either glutamine or selenium alone or in combination improves outcome in critical care requires a well designed prospective randomized controlled trial. To design such a trial we require the optimal dose and duration of the nutritional supplement (balancing efficacy and toxicity, ease of administration and cost) and then conduct an adequately powered trial. Such a trial is still lacking for these two agents. There are some supportive data for selenium but the case is less strong for parenteral glutamine and weakest for enteral glutamine.

  19. A randomized controlled exercise training trial on insulin sensitivity in African American men: The ARTIIS study: Major category: study design, statistical design, study protocols.

    PubMed

    Newton, Robert L; Johnson, William D; Hendrick, Chelsea; Harris, Melissa; Andrews, Emanuel; Johannsen, Neil; Rodarte, Ruben Q; Hsia, Daniel S; Church, Timothy S

    2015-07-01

    Lack of regular physical activity at prescribed intensity levels is a modifiable risk factor for insulin resistance and the development of diabetes. African American men are at increased risk for developing diabetes and most African American men are not meeting the current recommended levels of physical activity. The primary objective of the Aerobic Plus Resistance Training and Insulin Resistance in African American Men (ARTIIS) study is to determine the effectiveness of an exercise training intervention aimed at reducing diabetes risk factors in African American men at risk for developing diabetes. Insufficiently active 35-70 year old African American men with a family history of diabetes were eligible for the study. The 5-month randomized controlled trial assigns 116 men to an exercise training or healthy living control arm. The exercise training arm combines aerobic and resistance training according to the current national physical activity recommendations and is conducted in community (YMCA) facilities. The healthy living arm receives information promoting healthy lifestyle changes. Insulin response to an oral glucose load is the primary outcome measure, and changes in physiological parameters, cardiorespiratory fitness, strength, body composition, and psychological well-being comprise the secondary outcomes. The ARTIIS study is one of the first adequately powered, rigorously designed studies to investigate the effects of an aerobic plus resistance exercise training program and to assess adherence to exercise training in community facilities, in African American men. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Lack of efficacy of a reduced microparticle diet in a multi-centred trial of patients with active Crohn's disease.

    PubMed

    Lomer, Miranda C E; Grainger, Stephen L; Ede, Roland; Catterall, Adrian P; Greenfield, Simon M; Cowan, Russell E; Vicary, F Robin; Jenkins, Anthony P; Fidler, Helen; Harvey, Rory S; Ellis, Richard; McNair, Alistair; Ainley, Colin C; Thompson, Richard P H; Powell, Jonathan J

    2005-03-01

    Dietary microparticles, which are bacteria-sized and non-biological, found in the modern Western diet, have been implicated in both the aetiology and pathogenesis of Crohn's disease. Following on from the findings of a previous pilot study, we aimed to confirm whether a reduction in the amount of dietary microparticles facilitates induction of remission in patients with active Crohn's disease, in a single-blind, randomized, multi-centre, placebo controlled trial. Eighty-three patients with active Crohn's disease were randomly allocated in a 2 x 2 factorial design to a diet low or normal in microparticles and/or calcium for 16 weeks. All patients received a reducing dose of prednisolone for 6 weeks. Outcome measures were Crohn's disease activity index, Van Hees index, quality of life and a series of objective measures of inflammation including erythrocyte sedimentation rate, C-reactive protein, intestinal permeability and faecal calprotectin. After 16 weeks patients returned to their normal diet and were followed up for a further 36 weeks. Dietary manipulation provided no added effect to corticosteroid treatment on any of the outcome measures during the dietary trial (16 weeks) or follow-up (to 1 year); e.g., for logistic regression of Crohn's disease activity index based rates of remission (P=0.1) and clinical response (P=0.8), in normal versus low microparticle groups. Our adequately powered and carefully controlled dietary trial found no evidence that reducing microparticle intake aids remission in active Crohn's disease.

  1. Adequacy of depression treatment among college students in the United States.

    PubMed

    Eisenberg, Daniel; Chung, Henry

    2012-01-01

    There is no published evidence on the adequacy of depression care among college students and how this varies by subpopulations and provider types. We estimated the prevalence of minimally adequate treatment among students with significant past-year depressive symptoms. Data were collected via a confidential online survey of a random sample of 8488 students from 15 colleges and universities in the 2009 Healthy Minds Study. Depressive symptoms were assessed by the Patient Health Questionnaire-2, adapted to a past-year time frame. Students with probable depression were coded as having received minimally adequate depression care based on the criteria from Wang and colleagues (2005). Minimally adequate treatment was received by only 22% of depressed students. The likelihood of minimally adequate treatment was similarly low for both psychiatric medication and psychotherapy. Minimally adequate care was lower for students prescribed medication by a primary care provider as compared to a psychiatrist (P<.01). Racial/ethnic minority students were less likely to receive depression care (P<.01). Adequacy of depression care is a significant problem in the college population. Solutions will likely require greater availability of psychiatry care, better coordination between specialty and primary care using collaborative care models, and increased efforts to retain students in psychotherapy. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Knowledge, attitude and practice of mammography among women users of public health services.

    PubMed

    Marinho, Luiz Alberto Barcelos; Cecatti, José Guilherme; Osis, Maria José Duarte; Gurgel, Maria Salete Costa

    2008-04-01

    To evaluate knowledge, attitude and practice related to mammography among women users of local health services, identifying barriers to its performance. A total of 663 women were interviewed at 13 local health centers in a city of Southeastern Brazil, in 2001. Interviewees were randomly selected at each center and they were representative from different socioeconomic conditions. The number of interviewees at each center was proportional to monthly mean appointments. For data analysis, answers were described as knowledge, attitude, practice and their respective adequacies and then they were correlated with control variables through the chi-square test. Only 7.4% of the interviewees had adequate knowledge on mammography, while 97.1% of women had an adequate attitude. The same was seen for the practice of mammography that was adequate in 35.7% of the cases. The main barrier to mammography was lack of referral by physicians working at the health center (81.8%). There was an association between adequacy of attitude and five years or more of education and being married. There was also an association between adequacy of mammography practice and being employed and family income up to four minimum wages. Women users of local health services had no adequate knowledge and practice related to mammography despite having an adequate attitude about this exam.

  3. A random Q-switched fiber laser

    PubMed Central

    Tang, Yulong; Xu, Jianqiu

    2015-01-01

    Extensive studies have been performed on random lasers in which multiple-scattering feedback is used to generate coherent emission. Q-switching and mode-locking are well-known routes for achieving high peak power output in conventional lasers. However, in random lasers, the ubiquitous random cavities that are formed by multiple scattering inhibit energy storage, making Q-switching impossible. In this paper, widespread Rayleigh scattering arising from the intrinsic micro-scale refractive-index irregularities of fiber cores is used to form random cavities along the fiber. The Q-factor of the cavity is rapidly increased by stimulated Brillouin scattering just after the spontaneous emission is enhanced by random cavity resonances, resulting in random Q-switched pulses with high brightness and high peak power. This report is the first observation of high-brightness random Q-switched laser emission and is expected to stimulate new areas of scientific research and applications, including encryption, remote three-dimensional random imaging and the simulation of stellar lasing. PMID:25797520

  4. Probiotic supplementation in children with cystic fibrosis-a systematic review.

    PubMed

    Ananthan, Anitha; Balasubramanian, Haribalakrishna; Rao, Shripada; Patole, Sanjay

    2016-10-01

    Probiotics may benefit in cystic fibrosis (CF) as gut dysbiosis is associated with gastrointestinal symptoms and exacerbation of respiratory symptoms in CF. We conducted a systematic review of randomized controlled trials (RCTs) and non-RCTs of probiotic supplementation in children with CF, using the Cochrane methodology, preferred reporting items for systematic reviews (PRISMA) statement, and meta-analysis of observational studies in epidemiology (MOOSE) guidelines. Primary outcomes were pulmonary exacerbations, duration of hospitalization and antibiotics, and all-cause mortality. Secondary outcomes included gastrointestinal symptoms, markers of gut inflammation, and intestinal microbial balance. A total of nine studies (RCTs, 6, non-RCTs, 3; N = 275) with some methodological weaknesses were included in the review. The pooled estimate showed significant reduction in the rate of pulmonary exacerbation (fixed effects model, two parallel group RCTs and one cross-over trial: relative risk (RR) 0.25, (95 % confidence interval (95 % CI) 0.15,0.41); p < 0.00001; level of evidence: low) and decrease in fecal calprotectin (FCLP) levels (fixed effect model, three RCTs: mean difference (MD) -16.71, 95 % CI -27.30,-6.13); p = 0.002; level of evidence: low) after probiotic supplementation. Probiotic supplementation significantly improved gastrointestinal symptoms (one RCT, one non-RCT) and gut microbial balance (decreased Proteobacteria, increased Firmicutes, and Bacteroides in one RCT, one non-RCT). Limited low-quality evidence exists on the effects of probiotics in children with CF. Well-designed adequately powered RCTs assessing clinically meaningful outcomes are required to study this important issue. • Gut dysbiosis is frequent in children with cystic fibrosis due to frequent exposure to pathogens and antibiotics. • Probiotics decrease gut dysbiosis and improve gut maturity and function. What is New: • This comprehensive systematic review shows that current evidence on the safety and efficacy of probiotics in children with cystic fibrosis is limited and of low quality. • Well-designed and adequately powered trials assessing clinically important outcomes are required considering the health burden of cystic fibrosis and the potential benefits of probiotics.

  5. The importance of preservation of the ethical principle of equipoise in the design of clinical trials: relative impact of the methodological quality domains on the treatment effect in randomized controlled trials.

    PubMed

    Djulbegovic, Benjamin; Cantor, Alan; Clarke, Mike

    2003-01-01

    Previous research has identified methodological problems in the design and conduct of randomized trials that could, if left unaddressed, lead to biased results. In this report we discuss one such problem, inadequate control intervention, and argue that it can be by far the most important design characteristic of randomized trials in overestimating the effect of new treatments. Current guidelines for the design and reporting of randomized trials, such as the Consolidated Standards of Reporting Trials (CONSORT) statement, do not address the choice of the comparator intervention. We argue that an adequate control intervention can be selected if people designing a trial explicitly take into consideration the ethical principle of equipoise, also known as "the uncertainty principle."

  6. Three-dimensional versus two-dimensional ultrasound for assessing levonorgestrel intrauterine device location: A pilot study.

    PubMed

    Andrade, Carla Maria Araujo; Araujo Júnior, Edward; Torloni, Maria Regina; Moron, Antonio Fernandes; Guazzelli, Cristina Aparecida Falbo

    2016-02-01

    To compare the rates of success of two-dimensional (2D) and three-dimensional (3D) sonographic (US) examinations in locating and adequately visualizing levonorgestrel intrauterine devices (IUDs) and to explore factors associated with the unsuccessful viewing on 2D US. Transvaginal 2D and 3D US examinations were performed on all patients 1 month after insertion of levonorgestrel IUDs. The devices were considered adequately visualized on 2D US if both the vertical (shadow, upper and lower extremities) and the horizontal (two echogenic lines) shafts were identified. 3D volumes were also captured to assess the location of levonorgestrel IUDs on 3D US. Thirty women were included. The rates of adequate device visualization were 40% on 2D US (95% confidence interval [CI], 24.6; 57.7) and 100% on 3D US (95% CI, 88.6; 100.0). The device was not adequately visualized in all six women who had a retroflexed uterus, but it was adequately visualized in 12 of the 24 women (50%) who had a nonretroflexed uterus (95% CI, -68.6; -6.8). We found that 3D US is better than 2D US for locating and adequately visualizing levonorgestrel IUDs. Other well-designed studies with adequate power should be conducted to confirm this finding. © 2015 Wiley Periodicals, Inc.

  7. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser

    PubMed Central

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-01-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900–2000 nm. PMID:27416893

  8. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser.

    PubMed

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-07-15

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900-2000 nm.

  9. Tapered fiber based high power random laser.

    PubMed

    Zhang, Hanwei; Du, Xueyuan; Zhou, Pu; Wang, Xiaolin; Xu, Xiaojun

    2016-04-18

    We propose a novel high power random fiber laser (RFL) based on tapered fiber. It can overcome the power scaling limitation of RFL while maintaining good beam quality to a certain extent. An output power of 26.5 W has been achieved in a half-open cavity with one kilometer long tapered fiber whose core diameter gradually changes from 8 μm to 20 μm. The steady-state light propagation equations have been modified by taking into account the effective core area to demonstrate the tapered RFL through numerical calculations. The numerical model effectively describes the power characteristics of the tapered fiber based RFL, and both the calculating and experimental results show higher power exporting potential compared with the conventional single mode RFL.

  10. Titanium-nitride-oxide-coated coronary stents: insights from the available evidence.

    PubMed

    Karjalainen, Pasi P; Nammas, Wail

    2017-06-01

    Coating of stent surface with a biocompatible material is suggested to improve stent safety profile. A proprietary process was developed to coat titanium-nitride-oxide on the stent surface, based on plasma technology that uses the nano-synthesis of gas and metal. Preclinical in vitro and in vivo investigation confirmed blood compatibility of titanium (nitride-) oxide films. Titanium-nitride-oxide-coated stents demonstrated a better angiographic outcome, compared with bare-metal stents at mid-term follow-up; however, they failed to achieve non-inferiority for angiographic outcome versus second-generation drug-eluting stents. Observational studies showed adequate clinical outcome at mid-term follow-up. Non-randomized studies showed an outcome of titanium-nitride-oxide-coated stents comparable to - or better than - first-generation drug-eluting stents at long-term follow-up. Two randomized controlled trials demonstrated comparable efficacy outcome, and a better safety outcome of titanium-nitride-oxide-coated stents versus drug-eluting stents at long-term follow-up. Evaluation by optical coherence tomography at mid-term follow-up revealed better neointimal strut coverage associated with titanium-nitride-oxide-coated stents versus drug-eluting stents; yet, neointimal hyperplasia thickness was greater. Key messages Stents coated with titanium-nitride-oxide demonstrated biocompatibility in preclinical studies: they inhibit platelet and fibrin deposition, and reduce neointimal growth. In observational and non-randomized studies, titanium-nitride-oxide-coated stents were associated with adequate safety and efficacy outcome. In randomized trials of patients with acute coronary syndrome, titanium-nitride-oxide-coated stents were associated with a better safety outcome, compared with drug-eluting stents; efficacy outcome was comparable.

  11. Vertical jump biomechanics after plyometric, weight lifting, and combined (weight lifting + plyometric) training.

    PubMed

    Arabatzi, Fotini; Kellis, Eleftherios; Saèz-Saez De Villarreal, Eduardo

    2010-09-01

    The purpose of this study was to compare the effects of an Olympic weight lifting (OL), a plyometric (PL), and combined weight lifting + plyometric (WP) training program on vertical jump (VJ) biomechanics. Thirty-six men were assigned randomly to 4 groups: PL group (n = 9), OL group (n = 9), WP group (), and control (C) group (n = 8). The experimental groups trained 3 d.wk, for 8 weeks. Sagital kinematics, VJ height, power, and electromyographic (EMG) activity from rectus femoris (RF) and medial gastrocnemius (GAS) were collected during squat jumping and countermovement jumping (CMJ) before and after training. The results showed that all experimental groups improved VJ height (p < 0.05). The OL training improved power and muscle activation during the concentric phase of the CMJ while the subjects used a technique with wider hip and knee angles after training (p < 0.05). The PL group subjects did not change their CMJ technique although there was an increase in RF activation and a decrease of GAS activity after training (p < 0.05). The WP group displayed a decline in maximal hip angle and a lower activation during the CMJ after training (p < 0.05). These results indicate that all training programs are adequate for improving VJ performance. However, the mechanisms for these improvements differ between the 3 training protocols. Olympic weight lifting training might be more appropriate to achieve changes in VJ performance and power in the precompetition period of the training season. Emphasis on the PL exercises should be given when the competition period approaches, whereas the combination of OL and PL exercises may be used in the transition phases from precompetition to the competition period.

  12. Preference option randomized design (PORD) for comparative effectiveness research: Statistical power for testing comparative effect, preference effect, selection effect, intent-to-treat effect, and overall effect.

    PubMed

    Heo, Moonseong; Meissner, Paul; Litwin, Alain H; Arnsten, Julia H; McKee, M Diane; Karasz, Alison; McKinley, Paula; Rehm, Colin D; Chambers, Earle C; Yeh, Ming-Chin; Wylie-Rosett, Judith

    2017-01-01

    Comparative effectiveness research trials in real-world settings may require participants to choose between preferred intervention options. A randomized clinical trial with parallel experimental and control arms is straightforward and regarded as a gold standard design, but by design it forces and anticipates the participants to comply with a randomly assigned intervention regardless of their preference. Therefore, the randomized clinical trial may impose impractical limitations when planning comparative effectiveness research trials. To accommodate participants' preference if they are expressed, and to maintain randomization, we propose an alternative design that allows participants' preference after randomization, which we call a "preference option randomized design (PORD)". In contrast to other preference designs, which ask whether or not participants consent to the assigned intervention after randomization, the crucial feature of preference option randomized design is its unique informed consent process before randomization. Specifically, the preference option randomized design consent process informs participants that they can opt out and switch to the other intervention only if after randomization they actively express the desire to do so. Participants who do not independently express explicit alternate preference or assent to the randomly assigned intervention are considered to not have an alternate preference. In sum, preference option randomized design intends to maximize retention, minimize possibility of forced assignment for any participants, and to maintain randomization by allowing participants with no or equal preference to represent random assignments. This design scheme enables to define five effects that are interconnected with each other through common design parameters-comparative, preference, selection, intent-to-treat, and overall/as-treated-to collectively guide decision making between interventions. Statistical power functions for testing all these effects are derived, and simulations verified the validity of the power functions under normal and binomial distributions.

  13. Results of vardenafil mediated power Doppler ultrasound, contrast enhanced ultrasound and systematic random biopsies to detect prostate cancer.

    PubMed

    Morelli, Girolamo; Pagni, Riccardo; Mariani, Chiara; Minervini, Riccardo; Morelli, Andrea; Gori, Francesco; Ferdeghini, Ezio Maria; Paterni, Marco; Mauro, Eva; Guidi, Elisa; Armillotta, Nicola; Canale, Domenico; Vitti, Paolo; Caramella, Davide; Minervini, Andrea

    2011-06-01

    We evaluated the ability of the phosphodiesterase-5 inhibitor vardenafil to increase prostate microcirculation during power Doppler ultrasound. We also evaluated the results of contrast and vardenafil enhanced targeted biopsies compared to those of standard 12-core random biopsies to detect cancer. Between May 2008 and January 2010, 150 consecutive patients with prostate specific antigen more than 4 ng/ml at first diagnosis with negative digital rectal examination and transrectal ultrasound, and no clinical history of prostatitis underwent contrast enhanced power Doppler ultrasound (bolus injection of 2.4 ml SonoVue® contrast agent), followed by vardenafil enhanced power Doppler ultrasound (1 hour after oral administration of vardenafil 20 mg). All patients underwent standard 12-core transrectal ultrasound guided random prostate biopsy plus 1 further sampling from each suspected hypervascular lesion detected by contrast and vardenafil enhanced power Doppler ultrasound. Prostate cancer was detected in 44 patients (29.3%). Contrast and vardenafil enhanced power Doppler ultrasound detected suspicious, contrast enhanced and vardenafil enhanced areas in 112 (74.6%) and 110 patients (73.3%), and was diagnostic for cancer in 32 (28.5%) and 42 (38%), respectively. Analysis of standard technique, and contrast and vardenafil enhanced power Doppler ultrasound findings by biopsy core showed significantly higher detection using vardenafil vs contrast enhanced power Doppler ultrasound and standard technique (41.2% vs 22.7% and 8.1%, p <0.005 and <0.001, respectively). The detection rate of standard plus contrast or vardenafil enhanced power Doppler ultrasound was 10% and 11.7% (p not significant). Vardenafil enhanced power Doppler ultrasound enables excellent visualization of the microvasculature associated with cancer and can improve the detection rate compared to contrast enhanced power Doppler ultrasound and the random technique. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  14. Simulation of high temperature thermal energy storage system based on coupled metal hydrides for solar driven steam power plants

    DOE PAGES

    d'Entremont, Anna; Corgnale, Claudio; Hardy, Bruce; ...

    2018-01-11

    Concentrating solar power plants can achieve low cost and efficient renewable electricity production if equipped with adequate thermal energy storage systems. Metal hydride based thermal energy storage systems are appealing candidates due to their demonstrated potential for very high volumetric energy densities, high exergetic efficiencies, and low costs. The feasibility and performance of a thermal energy storage system based on NaMgH 2F hydride paired with TiCr 1.6Mn 0.2 is examined, discussing its integration with a solar-driven ultra-supercritical steam power plant. The simulated storage system is based on a laboratory-scale experimental apparatus. It is analyzed using a detailed transport model accountingmore » for the thermochemical hydrogen absorption and desorption reactions, including kinetics expressions adequate for the current metal hydride system. The results show that the proposed metal hydride pair can suitably be integrated with a high temperature steam power plant. The thermal energy storage system achieves output energy densities of 226 kWh/m 3, 9 times the DOE SunShot target, with moderate temperature and pressure swings. Also, simulations indicate that there is significant scope for performance improvement via heat-transfer enhancement strategies.« less

  15. Simulation of high temperature thermal energy storage system based on coupled metal hydrides for solar driven steam power plants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    d'Entremont, Anna; Corgnale, Claudio; Hardy, Bruce

    Concentrating solar power plants can achieve low cost and efficient renewable electricity production if equipped with adequate thermal energy storage systems. Metal hydride based thermal energy storage systems are appealing candidates due to their demonstrated potential for very high volumetric energy densities, high exergetic efficiencies, and low costs. The feasibility and performance of a thermal energy storage system based on NaMgH 2F hydride paired with TiCr 1.6Mn 0.2 is examined, discussing its integration with a solar-driven ultra-supercritical steam power plant. The simulated storage system is based on a laboratory-scale experimental apparatus. It is analyzed using a detailed transport model accountingmore » for the thermochemical hydrogen absorption and desorption reactions, including kinetics expressions adequate for the current metal hydride system. The results show that the proposed metal hydride pair can suitably be integrated with a high temperature steam power plant. The thermal energy storage system achieves output energy densities of 226 kWh/m 3, 9 times the DOE SunShot target, with moderate temperature and pressure swings. Also, simulations indicate that there is significant scope for performance improvement via heat-transfer enhancement strategies.« less

  16. 30 CFR 75.1101-5 - Installation of foam generator systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (b) Foam generator systems shall be equipped with a fire sensor which actuates the system, and each.... (d) Water, power, and chemicals required shall be adequate to maintain water or foam flow for no less...

  17. 30 CFR 75.1101-5 - Installation of foam generator systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... (b) Foam generator systems shall be equipped with a fire sensor which actuates the system, and each.... (d) Water, power, and chemicals required shall be adequate to maintain water or foam flow for no less...

  18. 30 CFR 75.1101-5 - Installation of foam generator systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (b) Foam generator systems shall be equipped with a fire sensor which actuates the system, and each.... (d) Water, power, and chemicals required shall be adequate to maintain water or foam flow for no less...

  19. Size-dependent piezoelectric energy-harvesting analysis of micro/nano bridges subjected to random ambient excitations

    NASA Astrophysics Data System (ADS)

    Radgolchin, Moeen; Moeenfard, Hamid

    2018-02-01

    The construction of self-powered micro-electro-mechanical units by converting the mechanical energy of the systems into electrical power has attracted much attention in recent years. While power harvesting from deterministic external excitations is state of the art, it has been much more difficult to derive mathematical models for scavenging electrical energy from ambient random vibrations, due to the stochastic nature of the excitations. The current research concerns analytical modeling of micro-bridge energy harvesters based on random vibration theory. Since classical elasticity fails to accurately predict the mechanical behavior of micro-structures, strain gradient theory is employed as a powerful tool to increase the accuracy of the random vibration modeling of the micro-harvester. Equations of motion of the system in the time domain are derived using the Lagrange approach. These are then utilized to determine the frequency and impulse responses of the structure. Assuming the energy harvester to be subjected to a combination of broadband and limited-band random support motion and transverse loading, closed-form expressions for mean, mean square, correlation and spectral density of the output power are derived. The suggested formulation is further exploited to investigate the effect of the different design parameters, including the geometric properties of the structure as well as the properties of the electrical circuit on the resulting power. Furthermore, the effect of length scale parameters on the harvested energy is investigated in detail. It is observed that the predictions of classical and even simple size-dependent theories (such as couple stress) appreciably differ from the findings of strain gradient theory on the basis of random vibration. This study presents a first-time modeling of micro-scale harvesters under stochastic excitations using a size-dependent approach and can be considered as a reliable foundation for future research in the field of micro/nano harvesters subjected to non-deterministic loads.

  20. Procedure for estimating orbital debris risks

    NASA Technical Reports Server (NTRS)

    Crafts, J. L.; Lindberg, J. P.

    1985-01-01

    A procedure for estimating the potential orbital debris risk to the world's populace from payloads or spent stages left in orbit on future missions is presented. This approach provides a consistent, but simple, procedure to assess the risk due to random reentry with an adequate accuracy level for making programmatic decisions on planned low Earth orbit missions.

  1. Graphite sample preparation for AMS in a high pressure and temperature press

    USGS Publications Warehouse

    Rubin, M.; Mysen, B.O.; Polach, H.

    1984-01-01

    A high pressure-high temperature press is used to make target material for accelerator mass spectrometry. Graphite was produced from typical 14C samples including oxalic acid and carbonates. Beam strength of 12C was generally adequate, but random radioactive contamination by 14C made age measurements impractical. ?? 1984.

  2. Graphite sample preparation for AMS in a high pressure and temperature press

    USGS Publications Warehouse

    Rubin, Meyer; Mysen, Bjorn O.; Polach, Henry

    1984-01-01

    A high pressure-temperature press is used to make target material for accelerator mass spectrometry. Graphite was produced from typical **1**4C samples including oxalic acid and carbonates. Beam strength of **1**2C was generally adequate, but random radioactive contamination by **1**4C made age measurements impractical.

  3. 25 CFR 542.10 - What are the minimum internal control standards for keno?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) The random number generator shall be linked to the computer system and shall directly relay the... information shall be generated by the computer system. (2) This documentation shall be restricted to... to the computer system shall be adequately restricted (i.e., passwords are changed at least quarterly...

  4. Evaluation of a Classroom-Based Psychosocial Intervention in Conflict-Affected Nepal: A Cluster Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Jordans, Mark J. D.; Komproe, Ivan H.; Tol, Wietse A.; Kohrt, Brandon A.; Luitel, Nagendra P.; Macy, Robert D.; de Jong, Joop T. V. M.

    2010-01-01

    Background: In situations of ongoing violence, childhood psychosocial and mental health problems require care. However, resources and evidence for adequate interventions are scarce for children in low- and middle-income countries. This study evaluated a school-based psychosocial intervention in conflict-affected, rural Nepal. Methods: A cluster…

  5. Anesthetic Efficacy of Meperidine in Teeth With Symptomatic Irreversible Pulpitis

    PubMed Central

    Mohajeri, Ladan; Salehi, Farnaz; Mehrvarzfar, Payman; Arfaee, Hamide; Bohluli, Behnam; Hamedy, Reza

    2015-01-01

    Achieving adequate pulpal anesthesia in mandibular teeth is always a challenge. Supplementary injections and using drugs in combination are some methods implemented to overcome this hurdle. In this randomized clinical trial, use of meperidine in conjunction with lidocaine in intraligamentary injection did not exhibit significant improvement in anesthesia. PMID:25849469

  6. AeroMACS Interference Simulations for Global Airports

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Apaza, Rafael D.

    2012-01-01

    Ran 18 scenarios with Visualyse Professional interference software (presented 2 most realistic scenarios). Scenario A: 85 large airports can transmit 1650 mW on each of 11 channels. 173 medium airports can transmit 825 mW on each of 6 channels. 5951 small airports can transmit 275 mW on one channel. Reducing power allowed for small airports in Scenario B increases allowable power for large and medium airports, but should not be necessary as Scenario A levels are more than adequate. These power limitations are conservative because we are assuming worst case with 100% duty.

  7. Prospective, randomized comparison between pulsatile GnRH therapy and combined gonadotropin (FSH+LH) treatment for ovulation induction in women with hypothalamic amenorrhea and underlying polycystic ovary syndrome.

    PubMed

    Dubourdieu, Sophie; Fréour, Thomas; Dessolle, Lionel; Barrière, Paul

    2013-05-01

    To compare the efficacy of pulsatile GnRH therapy versus combined gonadotropins for ovulation induction in women with both hypothalamic amenorrhoea and polycystic ovarian syndrome (HA/PCOS) according to their current hypothalamic status. This single-centre, prospective, randomized study was conducted in the Nantes University Hospital, France. Thirty consecutive patients were treated for ovulation induction with either pulsatile GnRH therapy or combined gonadotropins (rFSH+rLH). Frequency of adequate ovarian response (mono- or bi-follicular) and clinical pregnancy rate were then compared between both groups. Ovarian response was similar in both groups with comparable frequency of adequate ovarian response (73% vs 60%), but the clinical pregnancy rate was significantly higher in the pulsatile GnRH therapy group than in the combined gonadotropin group (46% vs 0%). HA/PCOS is a specific subgroup of infertile women. Pulsatile GnRH therapy is an effective and safe method of ovulation induction that can be used successfully in these patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Pressure ulcer healing promoted by adequate protein intake in rats

    PubMed Central

    Qin, Zhanfen; Wang, Yao; Zhao, Wei; Zhang, Yanan; Tian, Yiqing; Sun, Sujuan; Li, Xian

    2018-01-01

    The effect of protein intake on rat pressure ulcer healing was evaluated. One hundred rats were numbered according to body weight and then they were randomly divided into 4 groups (n=25) using the random number table. After rat models of stage II pressure ulcer were established, they were fed with feed containing different protein levels (10, 15, 20 and 25%). Healing time, pressure ulcer area, body weight, albumin (ALB) and hemoglobin (Hb) levels among groups were compared. Hematoxylin and eosin (H&E) staining was also performed to observe pressure ulcer tissue structure. In the healing process of pressure ulcer, rats with 20% protein intake had the shortest healing time and the smallest pressure ulcer area. Body weight, ALB and Hb levels were much closer to the normal level. H&E staining result also suggested that the pressure ulcer healing degree of rats with 20% protein intake was much better than the others. Adequate protein intake is therefore conducive to pressure ulcer healing, while excessive or insufficient protein intake has negative impact on healing. PMID:29731816

  9. Pressure ulcer healing promoted by adequate protein intake in rats.

    PubMed

    Qin, Zhanfen; Wang, Yao; Zhao, Wei; Zhang, Yanan; Tian, Yiqing; Sun, Sujuan; Li, Xian

    2018-05-01

    The effect of protein intake on rat pressure ulcer healing was evaluated. One hundred rats were numbered according to body weight and then they were randomly divided into 4 groups (n=25) using the random number table. After rat models of stage II pressure ulcer were established, they were fed with feed containing different protein levels (10, 15, 20 and 25%). Healing time, pressure ulcer area, body weight, albumin (ALB) and hemoglobin (Hb) levels among groups were compared. Hematoxylin and eosin (H&E) staining was also performed to observe pressure ulcer tissue structure. In the healing process of pressure ulcer, rats with 20% protein intake had the shortest healing time and the smallest pressure ulcer area. Body weight, ALB and Hb levels were much closer to the normal level. H&E staining result also suggested that the pressure ulcer healing degree of rats with 20% protein intake was much better than the others. Adequate protein intake is therefore conducive to pressure ulcer healing, while excessive or insufficient protein intake has negative impact on healing.

  10. Cascaded Raman lasing in a PM phosphosilicate fiber with random distributed feedback

    NASA Astrophysics Data System (ADS)

    Lobach, Ivan A.; Kablukov, Sergey I.; Babin, Sergey A.

    2018-02-01

    We report on the first demonstration of a linearly polarized cascaded Raman fiber laser based on a simple half-open cavity with a broadband composite reflector and random distributed feedback in a polarization maintaining phosphosilicate fiber operating beyond zero dispersion wavelength ( 1400 nm). With increasing pump power from a Yb-doped fiber laser at 1080 nm, the random laser generates subsequently 8 W at 1262 nm and 9 W at 1515 nm with polarization extinction ratio of 27 dB. The generation linewidths amount to about 1 nm and 3 nm, respectively, being almost independent of power, in correspondence with the theory of a cascaded random lasing.

  11. Effects of vibration and shock on the performance of gas-bearing space-power Brayton cycle turbomachinery. Part 3: Sinusoidal and random vibration data reduction and evaluation, and random vibration probability analysis

    NASA Technical Reports Server (NTRS)

    Tessarzik, J. M.; Chiang, T.; Badgley, R. H.

    1973-01-01

    The random vibration response of a gas bearing rotor support system has been experimentally and analytically investigated in the amplitude and frequency domains. The NASA Brayton Rotating Unit (BRU), a 36,000 rpm, 10 KWe turbogenerator had previously been subjected in the laboratory to external random vibrations, and the response data recorded on magnetic tape. This data has now been experimentally analyzed for amplitude distribution and magnetic tape. This data has now been experimentally analyzed for amplitude distribution and frequency content. The results of the power spectral density analysis indicate strong vibration responses for the major rotor-bearing system components at frequencies which correspond closely to their resonant frequencies obtained under periodic vibration testing. The results of amplitude analysis indicate an increasing shift towards non-Gaussian distributions as the input level of external vibrations is raised. Analysis of axial random vibration response of the BRU was performed by using a linear three-mass model. Power spectral densities, the root-mean-square value of the thrust bearing surface contact were calculated for specified input random excitation.

  12. A Bayesian sequential design with adaptive randomization for 2-sided hypothesis test.

    PubMed

    Yu, Qingzhao; Zhu, Lin; Zhu, Han

    2017-11-01

    Bayesian sequential and adaptive randomization designs are gaining popularity in clinical trials thanks to their potentials to reduce the number of required participants and save resources. We propose a Bayesian sequential design with adaptive randomization rates so as to more efficiently attribute newly recruited patients to different treatment arms. In this paper, we consider 2-arm clinical trials. Patients are allocated to the 2 arms with a randomization rate to achieve minimum variance for the test statistic. Algorithms are presented to calculate the optimal randomization rate, critical values, and power for the proposed design. Sensitivity analysis is implemented to check the influence on design by changing the prior distributions. Simulation studies are applied to compare the proposed method and traditional methods in terms of power and actual sample sizes. Simulations show that, when total sample size is fixed, the proposed design can obtain greater power and/or cost smaller actual sample size than the traditional Bayesian sequential design. Finally, we apply the proposed method to a real data set and compare the results with the Bayesian sequential design without adaptive randomization in terms of sample sizes. The proposed method can further reduce required sample size. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Power Calculations for Moderators in Multi-Site Cluster Randomized Trials

    ERIC Educational Resources Information Center

    Spybrook, Jessaca; Kelcey, Ben; Dong, Nianbo

    2016-01-01

    Cluster randomized trials (CRTs), or studies in which intact groups of individuals are randomly assigned to a condition, are becoming more common in evaluation studies of educational programs. A specific type of CRT in which clusters are randomly assigned to treatment within blocks or sites, known as multisite cluster randomized trials (MSCRTs),…

  14. Emergence of an optimal search strategy from a simple random walk

    PubMed Central

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2013-01-01

    In reports addressing animal foraging strategies, it has been stated that Lévy-like algorithms represent an optimal search strategy in an unknown environment, because of their super-diffusion properties and power-law-distributed step lengths. Here, starting with a simple random walk algorithm, which offers the agent a randomly determined direction at each time step with a fixed move length, we investigated how flexible exploration is achieved if an agent alters its randomly determined next step forward and the rule that controls its random movement based on its own directional moving experiences. We showed that our algorithm led to an effective food-searching performance compared with a simple random walk algorithm and exhibited super-diffusion properties, despite the uniform step lengths. Moreover, our algorithm exhibited a power-law distribution independent of uniform step lengths. PMID:23804445

  15. Emergence of an optimal search strategy from a simple random walk.

    PubMed

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2013-09-06

    In reports addressing animal foraging strategies, it has been stated that Lévy-like algorithms represent an optimal search strategy in an unknown environment, because of their super-diffusion properties and power-law-distributed step lengths. Here, starting with a simple random walk algorithm, which offers the agent a randomly determined direction at each time step with a fixed move length, we investigated how flexible exploration is achieved if an agent alters its randomly determined next step forward and the rule that controls its random movement based on its own directional moving experiences. We showed that our algorithm led to an effective food-searching performance compared with a simple random walk algorithm and exhibited super-diffusion properties, despite the uniform step lengths. Moreover, our algorithm exhibited a power-law distribution independent of uniform step lengths.

  16. Accelerating 21st Century Economic Growth by Implementation of the Lunar Solar Power System

    NASA Astrophysics Data System (ADS)

    Criswell, D. R.

    2002-01-01

    The World Energy Council (1) makes this declaration. "Given this dramatically uneven distribution and the limited evidence of improvement in economic growth in many developing countries, WEC at the 17th World Congress in Houston in September 1998 concluded that the number one priority in sustainable energy development today for all decision-makers in all countries is to extend access to commercial energy services to the people who do not now have it and to those who will come into the world in the next two decades, largely in developing countries, without such access." By ~2050 the global systems should supply 10 billion people approximately 6.7 kilowatts of thermal power per person or 61,360 kWt-h/y-person of energy. The economic equivalent is ~2 - 3 kWe of electric power per person. The energy must be environmentally clean. The energy must be sufficiently low in cost that the 2 billion poorest people, who now make 1,000 /y-person, can be provided with the new power. A survey of twenty-five options for providing adequate commercial electric power, including solar power satellites in orbit about Earth, concludes that only the Lunar Solar Power System can meet the WEC challenge (2, 3, 4, 5). Maurice Strong is the former CEO of Ontario Hydro and organizer of the 1992 Rio Environmental Summit. Quoting Strong - "I have checked it (LSP System) out with a number of experts, all of whom confirmed that the idea, which has been mooted for some time, may now be ripe to carry forward. --- The project would deliver net new energy to the Earth that is independent of the biosphere, would produce no CO2 or other polluting emissions and have minimal environmental impact compared with other energy sources." (6). Electric energy provided by the LSP System can accelerate terrestrial economic growth in several ways. A cost of less than 1 cent per kilowatt electric hour seems achievable. This allows poor nations to buy adequate energy. Increasing per capita use of electric power is associated with better human health and longer life. This increases the economic value of human capital in developing nations (7). The power can be abundant and clean. This reduces the environmental cost of commercial power and greatly reduces the economic uncertainties associated with using the power. The net new power enables creation of a greater range of goods from common materials and the recycling of products without depletion of other terrestrial resources (8). Rectennas can enable dual use of land and reduce the total land area devoted to the production and delivery of commercial power. All these factors work together to accelerate net new economic growth on Earth. 1. World Energy Council (2000) Energy for Tomorrow's World - Acting Now!, 175pp., Atalink Projects Ltd, London. 2. Criswell, D. R. (2001) Characteristics of commercial power systems to support a prosperous global economy, IAF-01- R.1.03, 7PP., Toulouse, France. 3. Criswell, David R. (2001) Lunar Solar Power System: Industrial Research, Development, and Demonstration, Session 1.2.2: Hydroelectricity, Nuclear Energy and New Renewables, 18th World Energy Congress. [http://www.wec.co.uk] 4. Criswell, David R. (2002) Energy Prosperity within the 21st Century and Beyond: Options and the Unique Roles of the Sun and the Moon. Chapter 9: Innovative Solutions To CO2 Stabilization, R. Watts (editor), Cambridge Un. Press 5. National Research Council (2001) Laying the Foundation for Space Solar Power: An assessment of NASA's Space Solar Power Investment Strategy, 80pp., National Academy Press. 6. Strong, Marice (2001) Where on Earth are We Going?, (See p. 351-352), 419pp., Random House (forward by Kofi Annan) 7. Criswell, D. R. (2000) Human wealth and evolving requirements on large-scale commercial power systems, IAF-00- R.1.03, 6pp., (Rio de Janeiro). 8. Criswell, D. R. (1994) Net growth in the two-planet economy, IAA-94-IAA.8.1.704, 10pp.

  17. Evaluation of a newly developed infant chest compression technique

    PubMed Central

    Smereka, Jacek; Bielski, Karol; Ladny, Jerzy R.; Ruetzler, Kurt; Szarpak, Lukasz

    2017-01-01

    Abstract Background: Providing adequate chest compression is essential during infant cardio-pulmonary-resuscitation (CPR) but was reported to be performed poor. The “new 2-thumb technique” (nTTT), which consists in using 2 thumbs directed at the angle of 90° to the chest while closing the fingers of both hands in a fist, was recently introduced. Therefore, the aim of this study was to compare 3 chest compression techniques, namely, the 2-finger-technique (TFT), the 2-thumb-technique (TTHT), and the nTTT in an randomized infant-CPR manikin setting. Methods: A total of 73 paramedics with at least 1 year of clinical experience performed 3 CPR settings with a chest compression:ventilation ratio of 15:2, according to current guidelines. Chest compression was performed with 1 out of the 3 chest compression techniques in a randomized sequence. Chest compression rate and depth, chest decompression, and adequate ventilation after chest compression served as outcome parameters. Results: The chest compression depth was 29 (IQR, 28–29) mm in the TFT group, 42 (40–43) mm in the TTHT group, and 40 (39–40) mm in the nTTT group (TFT vs TTHT, P < 0.001; TFT vs nTTT, P < 0.001; TTHT vs nTTT, P < 0.01). The median compression rate with TFT, TTHT, and nTTT varied and amounted to 136 (IQR, 133–144) min–1 versus 117 (115–121) min–1 versus 111 (109–113) min–1. There was a statistically significant difference in the compression rate between TFT and TTHT (P < 0.001), TFT and nTTT (P < 0.001), as well as TTHT and nTTT (P < 0.001). Incorrect decompressions after CC were significantly increased in the TTHT group compared with the TFT (P < 0.001) and the nTTT (P < 0.001) group. Conclusions: The nTTT provides adequate chest compression depth and rate and was associated with adequate chest decompression and possibility to adequately ventilate the infant manikin. Further clinical studies are necessary to confirm these initial findings. PMID:28383397

  18. Reporting of harm and safety results in randomized controlled trials published in 5 dermatology journals.

    PubMed

    Haddad, Cynthia; Sigha, Odette Berline; Lebrun-Vignes, Bénédicte; Chosidow, Olivier; Fardet, Laurence

    2017-07-01

    Randomized controlled trials (RCTs) are considered the gold standard for assessing efficacy and short-term harm of medicines. However, several studies have come to the conclusion that harm is less well reported than efficacy outcomes. To describe harm reporting in publications on dermatological RCTs and assess parameters that could influence the quality of harm reporting. Methodologic systematic review of dermatologic RCTs published from 2010 to 2014 in 5 dermatological journals. Among 110 assessed publications on RCTs, 80 (73%) adequately reported harm and 52% adequately reported its severity. Overall, 40% of the assessed manuscripts perfectly reported and discussed harm. The adequate reporting of harm was significantly associated with the type of trial (odds ratio [OR] 4.41, 95% confidence interval [CI] 1.60-12.35 for multicenter compared with monocentric trials) and having a predefined method for collecting harm data (OR 5.93, 95% CI 2.26-15.56). Reporting of harm severity was better in pharmacologic trials (OR 6.48, 95% CI 2.00-21.0) compared with nonpharmacologic trials and in trials for which a method for collecting harm (OR 5.65, 95% CI 2.00-16.4) and its severity (OR 3.60, 95% CI 1.00-12.8) was defined before the study onset. Assessment was restricted to RCTs and 5 dermatological journals. Harm is quite well reported in dermatologic journals. Efforts should be made on reporting severity of harm. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Methodological Reporting Quality of Randomized Controlled Trials in 3 Leading Diabetes Journals From 2011 to 2013 Following CONSORT Statement: A System Review.

    PubMed

    Zhai, Xiao; Wang, Yiran; Mu, Qingchun; Chen, Xiao; Huang, Qin; Wang, Qijin; Li, Ming

    2015-07-01

    To appraise the current reporting methodological quality of randomized clinical trials (RCTs) in 3 leading diabetes journals.We systematically searched the literature for RCTs in Diabetes Care, Diabetes and Diabetologia from 2011 to 2013.Characteristics were extracted based on Consolidated Standards of Reporting Trials (CONSORT) statement. Generation of allocation, concealment of allocation, intention-to-treat (ITT) analysis and handling of dropouts were defined as primary outcome and "low risk of bias." Sample size calculation, type of intervention, country, number of patients, funding source were also revealed and descriptively reported. Trials were compared among journals, study years, and other characters.A total of 305 RCTs were enrolled in this study. One hundred eight (35.4%) trials reported adequate generation of allocation, 87 (28.5%) trials reported adequate concealment of allocation, 53 (23.8%) trials used ITT analysis, and 130 (58.3%) trials were adequate in handling of dropouts. Only 15 (4.9%) were "low risk of bias" trials. Studies at a large scale (n > 100) or from European presented with more "low risk of bias" trials than those at a small scale (n ≤ 100) or from other regions. No improvements were found in these 3 years.This study shows that methodological reporting quality of RCTs in the major diabetes journals remains suboptimal. It can be further improved to meet and keep up with the standards of the CONSORT statement.

  20. Adverse prognostic value of peritumoral vascular invasion: is it abrogated by adequate endocrine adjuvant therapy? Results from two International Breast Cancer Study Group randomized trials of chemoendocrine adjuvant therapy for early breast cancer

    PubMed Central

    Viale, G.; Giobbie-Hurder, A.; Gusterson, B. A.; Maiorano, E.; Mastropasqua, M. G.; Sonzogni, A.; Mallon, E.; Colleoni, M.; Castiglione-Gertsch, M.; Regan, M. M.; Brown, R. W.; Golouh, R.; Crivellari, D.; Karlsson, P.; Öhlschlegel, C.; Gelber, R. D.; Goldhirsch, A.; Coates, A. S.

    2010-01-01

    Background: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer. Patients and methods: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin–eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years). Results: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy. Conclusion: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy. PMID:19633051

  1. NASA Office of Aeronautics and Space Technology Summer Workshop. Volume 4: Power technology panel

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technology requirements in the areas of energy sources and conversion, power processing, distribution, conversion, and transmission, and energy storage are identified for space shuttle payloads. It is concluded that the power system technology currently available is adequate to accomplish all missions in the 1973 Mission Model, but that further development is needed to support space opportunities of the future as identified by users. Space experiments are proposed in the following areas: power generation in space, advanced photovoltaic energy converters, solar and nuclear thermoelectric technology, nickel-cadmium batteries, flywheels (mechanical storage), satellite-to-ground transmission and reconversion systems, and regenerative fuel cells.

  2. A new u-statistic with superior design sensitivity in matched observational studies.

    PubMed

    Rosenbaum, Paul R

    2011-09-01

    In an observational or nonrandomized study of treatment effects, a sensitivity analysis indicates the magnitude of bias from unmeasured covariates that would need to be present to alter the conclusions of a naïve analysis that presumes adjustments for observed covariates suffice to remove all bias. The power of sensitivity analysis is the probability that it will reject a false hypothesis about treatment effects allowing for a departure from random assignment of a specified magnitude; in particular, if this specified magnitude is "no departure" then this is the same as the power of a randomization test in a randomized experiment. A new family of u-statistics is proposed that includes Wilcoxon's signed rank statistic but also includes other statistics with substantially higher power when a sensitivity analysis is performed in an observational study. Wilcoxon's statistic has high power to detect small effects in large randomized experiments-that is, it often has good Pitman efficiency-but small effects are invariably sensitive to small unobserved biases. Members of this family of u-statistics that emphasize medium to large effects can have substantially higher power in a sensitivity analysis. For example, in one situation with 250 pair differences that are Normal with expectation 1/2 and variance 1, the power of a sensitivity analysis that uses Wilcoxon's statistic is 0.08 while the power of another member of the family of u-statistics is 0.66. The topic is examined by performing a sensitivity analysis in three observational studies, using an asymptotic measure called the design sensitivity, and by simulating power in finite samples. The three examples are drawn from epidemiology, clinical medicine, and genetic toxicology. © 2010, The International Biometric Society.

  3. Accuracy of indirect estimation of power output from uphill performance in cycling.

    PubMed

    Millet, Grégoire P; Tronche, Cyrille; Grappe, Frédéric

    2014-09-01

    To use measurement by cycling power meters (Pmes) to evaluate the accuracy of commonly used models for estimating uphill cycling power (Pest). Experiments were designed to explore the influence of wind speed and steepness of climb on accuracy of Pest. The authors hypothesized that the random error in Pest would be largely influenced by the windy conditions, the bias would be diminished in steeper climbs, and windy conditions would induce larger bias in Pest. Sixteen well-trained cyclists performed 15 uphill-cycling trials (range: length 1.3-6.3 km, slope 4.4-10.7%) in a random order. Trials included different riding position in a group (lead or follow) and different wind speeds. Pmes was quantified using a power meter, and Pest was calculated with a methodology used by journalists reporting on the Tour de France. Overall, the difference between Pmes and Pest was -0.95% (95%CI: -10.4%, +8.5%) for all trials and 0.24% (-6.1%, +6.6%) in conditions without wind (<2 m/s). The relationship between percent slope and the error between Pest and Pmes were considered trivial. Aerodynamic drag (affected by wind velocity and orientation, frontal area, drafting, and speed) is the most confounding factor. The mean estimated values are close to the power-output values measured by power meters, but the random error is between ±6% and ±10%. Moreover, at the power outputs (>400 W) produced by professional riders, this error is likely to be higher. This observation calls into question the validity of releasing individual values without reporting the range of random errors.

  4. 14 CFR 91.205 - Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: (1) Airspeed indicator. (2) Altimeter. (3) Magnetic direction indicator. (4) Tachometer for each... aircraft is operated for hire, one electric landing light. (5) An adequate source of electrical energy for...

  5. 14 CFR 91.205 - Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: (1) Airspeed indicator. (2) Altimeter. (3) Magnetic direction indicator. (4) Tachometer for each... aircraft is operated for hire, one electric landing light. (5) An adequate source of electrical energy for...

  6. 14 CFR 91.205 - Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: (1) Airspeed indicator. (2) Altimeter. (3) Magnetic direction indicator. (4) Tachometer for each... aircraft is operated for hire, one electric landing light. (5) An adequate source of electrical energy for...

  7. 14 CFR 91.205 - Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: (1) Airspeed indicator. (2) Altimeter. (3) Magnetic direction indicator. (4) Tachometer for each... aircraft is operated for hire, one electric landing light. (5) An adequate source of electrical energy for...

  8. Harnessing Pavement Power : Developing Renewable Energy Technology in the Public Right-of-Way

    DOT National Transportation Integrated Search

    2013-09-18

    Intelligent Compaction (IC) of soil and asphalt mixes is an innovative approach that has been utilized to achieve uniform, adequate compaction of pavement layers during construction. Commercially available IC products provide machine specific compact...

  9. Volumetric Security Alarm Based on a Spherical Ultrasonic Transducer Array

    NASA Astrophysics Data System (ADS)

    Sayin, Umut; Scaini, Davide; Arteaga, Daniel

    Most of the existent alarm systems depend on physical or visual contact. The detection area is often limited depending on the type of the transducer, creating blind spots. Our proposition is a truly volumetric alarm system that can detect any movement in the intrusion area, based on monitoring the change over time of the impulse response of the room, which acts as an acoustic footprint. The device depends on an omnidirectional ultrasonic transducer array emitting sweep signals to calculate the impulse response in short intervals. Any change in the room conditions is monitored through a correlation function. The sensitivity of the alarm to different objects and different environments depends on the sweep duration, sweep bandwidth, and sweep interval. Successful detection of intrusions also depends on the size of the monitoring area and requires an adjustment of emitted ultrasound power. Strong air flow affects the performance of the alarm. A method for separating moving objects from strong air flow is devised using an adaptive thresholding on the correlation function involving a series of impulse response measurements. The alarm system can be also used for fire detection since air flow sourced from heating objects differ from random nature of the present air flow. Several measurements are made to test the integrity of the alarm in rooms sizing from 834-2080m3 with irregular geometries and various objects. The proposed system can efficiently detect intrusion whilst adequate emitting power is provided.

  10. Five-year results of a randomised controlled trial comparing mobile and fixed bearings in total knee replacement.

    PubMed

    Breeman, S; Campbell, M K; Dakin, H; Fiddian, N; Fitzpatrick, R; Grant, A; Gray, A; Johnston, L; MacLennan, G S; Morris, R W; Murray, D W

    2013-04-01

    There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery. There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs. In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.

  11. Knowledge of medical students of Tehran University of Medical Sciences regarding plagiarism.

    PubMed

    Gharedaghi, Mohammad Hadi; Nourijelyani, Keramat; Salehi Sadaghiani, Mohammad; Yousefzadeh-Fard, Yashar; Gharedaghi, Azadeh; Javadian, Pouya; Morteza, Afsaneh; Andrabi, Yasir; Nedjat, Saharnaz

    2013-07-13

    The core concept of plagiarism is defined as the use of other people's ideas or words without proper acknowledgement. Herein, we used a questionnaire to assess the knowledge of students of Tehran University of Medical Sciences (TUMS) regarding plagiarism and copyright infringement. The questionnaire comprised 8 questions. The first six questions of the questionnaire were translations of exercises of a book about academic writing and were concerning plagiarism in preparing articles. Questions number 7 and 8 (which were concerning plagiarism in preparing Microsoft PowerPoint slideshows and copyright infringement, respectively) were developed by the authors of the present study. The validity of the questionnaire was approved by five experts in the field of epidemiology and biostatistics. A pilot study consisting of a test and retest was carried to assess the reliability of the questionnaire. The sampling method was stratified random sampling, and the questionnaire was handed out to 74 interns of TUMS during July and August 2011. 14.9% of the students correctly answered the first six questions. 44.6% of the students were adequately familiar with proper referencing in Microsoft PowerPoint slideshows. 16.2% of the students understood what constitutes copyright infringement. The number of correctly answered questions by the students was directly proportionate to the number of their published articles. Knowledge of students of TUMS regarding plagiarism and copyright infringement is quite poor. Courses with specific focus on plagiarism and copyright infringement might help in this regard.

  12. Miniature Radioisotope Thermoelectric Power Cubes

    NASA Technical Reports Server (NTRS)

    Patel, Jagdish U.; Fleurial, Jean-Pierre; Snyder, G. Jeffrey; Caillat, Thierry

    2004-01-01

    Cube-shaped thermoelectric devices energized by a particles from radioactive decay of Cm-244 have been proposed as long-lived sources of power. These power cubes are intended especially for incorporation into electronic circuits that must operate in dark, extremely cold locations (e.g., polar locations or deep underwater on Earth, or in deep interplanetary space). Unlike conventional radioisotope thermoelectric generators used heretofore as central power sources in some spacecraft, the proposed power cubes would be small enough (volumes would range between 0.1 and 0.2 cm3) to play the roles of batteries that are parts of, and dedicated to, individual electronic-circuit packages. Unlike electrochemical batteries, these power cubes would perform well at low temperatures. They would also last much longer: given that the half-life of Cm-244 is 18 years, a power cube could remain adequate as a power source for years, depending on the power demand in its particular application.

  13. Design and implementation of a dental caries prevention trial in remote Canadian Aboriginal communities.

    PubMed

    Harrison, Rosamund; Veronneau, Jacques; Leroux, Brian

    2010-05-13

    The goal of this cluster randomized trial is to test the effectiveness of a counseling approach, Motivational Interviewing, to control dental caries in young Aboriginal children. Motivational Interviewing, a client-centred, directive counseling style, has not yet been evaluated as an approach for promotion of behaviour change in indigenous communities in remote settings. Aboriginal women were hired from the 9 communities to recruit expectant and new mothers to the trial, administer questionnaires and deliver the counseling to mothers in the test communities. The goal is for mothers to receive the intervention during pregnancy and at their child's immunization visits. Data on children's dental health status and family dental health practices will be collected when children are 30-months of age. The communities were randomly allocated to test or control group by a random "draw" over community radio. Sample size and power were determined based on an anticipated 20% reduction in caries prevalence. Randomization checks were conducted between groups. In the 5 test and 4 control communities, 272 of the original target sample size of 309 mothers have been recruited over a two-and-a-half year period. A power calculation using the actual attained sample size showed power to be 79% to detect a treatment effect. If an attrition fraction of 4% per year is maintained, power will remain at 80%. Power will still be > 90% to detect a 25% reduction in caries prevalence. The distribution of most baseline variables was similar for the two randomized groups of mothers. However, despite the random assignment of communities to treatment conditions, group differences exist for stage of pregnancy and prior tooth extractions in the family. Because of the group imbalances on certain variables, control of baseline variables will be done in the analyses of treatment effects. This paper explains the challenges of conducting randomized trials in remote settings, the importance of thorough community collaboration, and also illustrates the likelihood that some baseline variables that may be clinically important will be unevenly split in group-randomized trials when the number of groups is small. This trial is registered as ISRCTN41467632.

  14. Design and implementation of a dental caries prevention trial in remote Canadian Aboriginal communities

    PubMed Central

    2010-01-01

    Background The goal of this cluster randomized trial is to test the effectiveness of a counseling approach, Motivational Interviewing, to control dental caries in young Aboriginal children. Motivational Interviewing, a client-centred, directive counseling style, has not yet been evaluated as an approach for promotion of behaviour change in indigenous communities in remote settings. Methods/design Aboriginal women were hired from the 9 communities to recruit expectant and new mothers to the trial, administer questionnaires and deliver the counseling to mothers in the test communities. The goal is for mothers to receive the intervention during pregnancy and at their child's immunization visits. Data on children's dental health status and family dental health practices will be collected when children are 30-months of age. The communities were randomly allocated to test or control group by a random "draw" over community radio. Sample size and power were determined based on an anticipated 20% reduction in caries prevalence. Randomization checks were conducted between groups. Discussion In the 5 test and 4 control communities, 272 of the original target sample size of 309 mothers have been recruited over a two-and-a-half year period. A power calculation using the actual attained sample size showed power to be 79% to detect a treatment effect. If an attrition fraction of 4% per year is maintained, power will remain at 80%. Power will still be > 90% to detect a 25% reduction in caries prevalence. The distribution of most baseline variables was similar for the two randomized groups of mothers. However, despite the random assignment of communities to treatment conditions, group differences exist for stage of pregnancy and prior tooth extractions in the family. Because of the group imbalances on certain variables, control of baseline variables will be done in the analyses of treatment effects. This paper explains the challenges of conducting randomized trials in remote settings, the importance of thorough community collaboration, and also illustrates the likelihood that some baseline variables that may be clinically important will be unevenly split in group-randomized trials when the number of groups is small. Trial registration This trial is registered as ISRCTN41467632. PMID:20465831

  15. Social power and opinion formation in complex networks

    NASA Astrophysics Data System (ADS)

    Jalili, Mahdi

    2013-02-01

    In this paper we investigate the effects of social power on the evolution of opinions in model networks as well as in a number of real social networks. A continuous opinion formation model is considered and the analysis is performed through numerical simulation. Social power is given to a proportion of agents selected either randomly or based on their degrees. As artificial network structures, we consider scale-free networks constructed through preferential attachment and Watts-Strogatz networks. Numerical simulations show that scale-free networks with degree-based social power on the hub nodes have an optimal case where the largest number of the nodes reaches a consensus. However, given power to a random selection of nodes could not improve consensus properties. Introducing social power in Watts-Strogatz networks could not significantly change the consensus profile.

  16. New Estimates of Design Parameters for Clustered Randomization Studies: Findings from North Carolina and Florida. Working Paper 43

    ERIC Educational Resources Information Center

    Xu, Zeyu; Nichols, Austin

    2010-01-01

    The gold standard in making causal inference on program effects is a randomized trial. Most randomization designs in education randomize classrooms or schools rather than individual students. Such "clustered randomization" designs have one principal drawback: They tend to have limited statistical power or precision. This study aims to…

  17. Randomized trials published in some Chinese journals: how many are randomized?

    PubMed

    Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David

    2009-07-02

    The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9-7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18-2.13, and relative risk 14.42, 95% confidence interval 9.40-22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83-14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0-81.0). Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing to a lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed.

  18. Randomized trials published in some Chinese journals: how many are randomized?

    PubMed Central

    Wu, Taixiang; Li, Youping; Bian, Zhaoxiang; Liu, Guanjian; Moher, David

    2009-01-01

    Background The approximately 1100 medical journals now active in China are publishing a rapidly increasing number of research reports, including many studies identified by their authors as randomized controlled trials. It has been noticed that these reports mostly present positive results, and their quality and authenticity have consequently been called into question. We investigated the adequacy of randomization of clinical trials published in recent years in China to determine how many of them met acceptable standards for allocating participants to treatment groups. Methods The China National Knowledge Infrastructure electronic database was searched for reports of randomized controlled trials on 20 common diseases published from January 1994 to June 2005. From this sample, a subset of trials that appeared to have used randomization methods was selected. Twenty-one investigators trained in the relevant knowledge, communication skills and quality control issues interviewed the original authors of these trials about the participant randomization methods and related quality-control features of their trials. Results From an initial sample of 37,313 articles identified in the China National Knowledge Infrastructure database, we found 3137 apparent randomized controlled trials. Of these, 1452 were studies of conventional medicine (published in 411 journals) and 1685 were studies of traditional Chinese medicine (published in 352 journals). Interviews with the authors of 2235 of these reports revealed that only 207 studies adhered to accepted methodology for randomization and could on those grounds be deemed authentic randomized controlled trials (6.8%, 95% confidence interval 5.9–7.7). There was no statistically significant difference in the rate of authenticity between randomized controlled trials of traditional interventions and those of conventional interventions. Randomized controlled trials conducted at hospitals affiliated to medical universities were more likely to be authentic than trials conducted at level 3 and level 2 hospitals (relative risk 1.58, 95% confidence interval 1.18–2.13, and relative risk 14.42, 95% confidence interval 9.40–22.10, respectively). The likelihood of authenticity was higher in level 3 hospitals than in level 2 hospitals (relative risk 9.32, 95% confidence interval 5.83–14.89). All randomized controlled trials of pre-market drug clinical trial were authentic by our criteria. Of the trials conducted at university-affiliated hospitals, 56.3% were authentic (95% confidence interval 32.0–81.0). Conclusion Most reports of randomized controlled trials published in some Chinese journals lacked an adequate description of randomization. Similarly, most so called 'randomized controlled trials' were not real randomized controlled trials owing toa lack of adequate understanding on the part of the authors of rigorous clinical trial design. All randomized controlled trials of pre-market drug clinical trial included in this research were authentic. Randomized controlled trials conducted by authors in high level hospitals, especially in hospitals affiliated to medical universities had a higher rate of authenticity. That so many non-randomized controlled trials were published as randomized controlled trials reflected the fact that peer review needs to be improved and a good practice guide for peer review including how to identify the authenticity of the study urgently needs to be developed. PMID:19573242

  19. Random walk study of electron motion in helium in crossed electromagnetic fields

    NASA Technical Reports Server (NTRS)

    Englert, G. W.

    1972-01-01

    Random walk theory, previously adapted to electron motion in the presence of an electric field, is extended to include a transverse magnetic field. In principle, the random walk approach avoids mathematical complexity and concomitant simplifying assumptions and permits determination of energy distributions and transport coefficients within the accuracy of available collisional cross section data. Application is made to a weakly ionized helium gas. Time of relaxation of electron energy distribution, determined by the random walk, is described by simple expressions based on energy exchange between the electron and an effective electric field. The restrictive effect of the magnetic field on electron motion, which increases the required number of collisions per walk to reach a terminal steady state condition, as well as the effect of the magnetic field on electron transport coefficients and mean energy can be quite adequately described by expressions involving only the Hall parameter.

  20. A Preliminary Analysis of the Flying Qualities of the Consolidated Vultee MX-813 Delta-Wing Airplane Configuration at Transonic and Low Supersonic Speeds as Determined from Flights of Rocket-Powered Models

    NASA Technical Reports Server (NTRS)

    Mitcham, Grady L.

    1949-01-01

    A preliminary analysis of the flying qualities of the Consolidated Vultee MX-813 delta-wing airplane configuration has been made based on the results obtained from the first two 1/8 scale models flown at the NACA Pilotless Aircraft Research Station, Wallop's Island, VA. The Mach number range covered in the tests was from 0.9 to 1.2. The analysis indicates adequate elevator control for trim in level flight over the speed range investigated. Through the transonic range there is a mild trim change with a slight tucking-under tendency. The elevator control effectiveness in the supersonic range is reduced to about one-half the subsonic value although sufficient control for maneuvering is available as indicated by the fact that 10 deg elevator deflection produced 5g acceleration at Mach number of 1.2 at 40,000 feet.The elevator control forces are high and indicate the power required of the boost system. The damping. of the short-period oscillation is adequate at sea-level but is reduced at 40,000 feet. The directional stability appears adequate for the speed range and angles of attack covered.

  1. Intrahepatic Cholangiocarcinoma: expert consensus statement

    PubMed Central

    Weber, Sharon M; Ribero, Dario; O=Reilly, Eileen M; Kokudo, Norihiro; Miyazaki, Masaru; Pawlik, Timothy M

    2015-01-01

    An American Hepato-Pancreato-Biliary Association (AHPBA)-sponsored consensus meeting of expert panellists met on 15 January 2014 to review current evidence on the management of intrahepatic cholangiocarcinoma (ICC) in order to establish practice guidelines and to agree on consensus statements. The treatment of ICC requires a coordinated, multidisciplinary approach to optimize survival. Biopsy is not necessary if the surgeon suspects ICC and is planning curative resection, although biopsy should be obtained before systemic or locoregional therapies are initiated. Assessment of resectability is best accomplished using cross-sectional imaging [computed tomography (CT) or magnetic resonance imaging (MRI)], but the role of positron emission tomography (PET) is unclear. Resectability in ICC is defined by the ability to completely remove the disease while leaving an adequate liver remnant. Extrahepatic disease, multiple bilobar or multicentric tumours, and lymph node metastases beyond the primary echelon are contraindications to resection. Regional lymphadenectomy should be considered a standard part of surgical therapy. In patients with high-risk features, the routine use of diagnostic laparoscopy is recommended. The preoperative diagnosis of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC–CC) by imaging studies is extremely difficult. Surgical resection remains the mainstay of treatment, but survival is worse than in HCC alone. There are no adequately powered, randomized Phase III trials that can provide definitive recommendations for adjuvant therapy for ICC. Patients with high-risk features (lymphovascular invasion, multicentricity or satellitosis, large tumours) should be encouraged to enrol in clinical trials and to consider adjuvant therapy. Cisplatin plus gemcitabine represents the standard-of-care, front-line systemic therapy for metastatic ICC. Genomic analyses of biliary cancers support the development of targeted therapeutic interventions. PMID:26172134

  2. Intravenous lipids in preterm infants: impact on laboratory and clinical outcomes and long-term consequences.

    PubMed

    Vlaardingerbroek, Hester; van Goudoever, Johannes B

    2015-01-01

    Postnatal growth failure is still one of the most commonly observed morbidities in preterm infants. Intolerance of enteral nutrition is a common problem in these infants and in neonates with surgical conditions. Therefore, adequate parenteral nutrition is crucial to support organ development, including that of the brain. Short-term studies on the early introduction of parenteral lipids have demonstrated that early lipid administration seems safe and well tolerated and prevents essential fatty acid deficiency. Further well-designed and adequately powered studies are necessary to determine the optimal dose of lipid infusion and the long-term effects on morbidity, growth, and neurodevelopment. Administration of a pure soybean oil emulsion might result in excess formation of proinflammatory eicosanoids and peroxidation, and their use reduces the availability of the long-chain polyunsaturated fatty acids necessary for central nervous system development and immune function. Alternatives to the use of pure soybean oils include emulsions with partial replacement of soybean oil with medium-chain triglycerides, olive oil, and/or fish oil. These newer lipid emulsions offer many theoretical advantages. Future large-scale randomized controlled trials in premature infants should demonstrate whether these newer lipid emulsions are truly safe and result in improved short- and long-term outcomes. It seems safe to start lipid emulsions from birth onward at a rate of 2 g lipids/kg/day (based on short-term results only). Mixed lipid emulsions, including those containing fish oil, seem to reduce nosocomial infections in preterm infants and might reduce bile acid accumulation. Liver damage may be reduced by decreasing or removing lipids from parenteral nutrition or may be reduced by using fish oil-containing lipid emulsions containing high levels of vitamin E. © 2015 S. Karger AG, Basel.

  3. Determination of the cumulus size distribution from LANDSAT pictures

    NASA Technical Reports Server (NTRS)

    Karg, E.; Mueller, H.; Quenzel, H.

    1983-01-01

    Varying insolation causes undesirable thermic stress to the receiver of a solar power plant. The rapid change of insolation depends on the size distribution of the clouds; in order to measure these changes, it is suitable to determine typical cumulus size distributions. For this purpose, LANDSAT-images are adequate. Several examples of cumulus size distributions will be presented and their effects on the operation of a solar power plant are discussed.

  4. Electric vehicle power train instrumentation: Some constraints and considerations

    NASA Technical Reports Server (NTRS)

    Triner, J. E.; Hansen, I. G.

    1977-01-01

    The application of pulse modulation control (choppers) to dc motors creates unique instrumentation problems. In particular, the high harmonic components contained in the current waveforms require frequency response accommodations not normally considered in dc instrumentation. In addition to current sensing, accurate power measurement requires not only adequate frequency response but must also address phase errors caused by the finite bandwidths and component characteristics involved. The implications of these problems are assessed.

  5. A Randomized Controlled Trial Comparing the Low FODMAP Diet vs. Modified NICE Guidelines in US Adults with IBS-D.

    PubMed

    Eswaran, Shanti L; Chey, William D; Han-Markey, Theresa; Ball, Sarah; Jackson, Kenya

    2016-12-01

    There has been an increasing interest in the role of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) in irritable bowel syndrome (IBS). We report results from the first randomized controlled trial of the low FODMAP diet in US adults with IBS and diarrhea (IBS-D). The objectives were to compare the efficacy of the low FODMAP diet vs. a diet based upon modified National Institute for Health and Care Excellence guidelines (mNICE) on overall and individual symptoms in IBS-D patients. This was a single-center, randomized-controlled trial of adult patients with IBS-D (Rome III) which compared 2 diet interventions. After a 2-week screening period, eligible patients were randomized to a low FODMAP or mNICE diet for 4 weeks. The primary end point was the proportion of patients reporting adequate relief of IBS-D symptoms ≥50% of intervention weeks 3-4. Secondary outcomes included a composite end point which required response in both abdominal pain (≥30% reduction in mean daily pain score compared with baseline) and stool consistency (decrease in mean daily Bristol Stool Form of ≥1 compared with baseline), abdominal pain and stool consistency responders, and other key individual IBS symptoms assessed using daily questionnaires. After screening, 92 subjects (65 women, median age 42.6 years) were randomized. Eighty-four patients completed the study (45 low FODMAP, 39 mNICE). Baseline demographics, symptom severity, and nutrient intake were similar between groups. Fifty-two percent of the low FODMAP vs. 41% of the mNICE group reported adequate relief of their IBS-D symptoms (P=0.31). Though there was no significant difference in the proportion of composite end point responders (P=0.13), the low FODMAP diet resulted in a higher proportion of abdominal pain responders compared with the mNICE group (51% vs. 23%, P=0.008). Compared with baseline scores, the low FODMAP diet led to greater reductions in average daily scores of abdominal pain, bloating, consistency, frequency, and urgency than the mNICE diet. In this US trial, 40-50% of patients reported adequate relief of their IBS-D symptoms with the low FODMAP diet or a diet based on modified NICE guidelines. The low FODMAP diet led to significantly greater improvement in individual IBS symptoms, particularly pain and bloating, compared with the mNICE diet.

  6. Contact Time in Random Walk and Random Waypoint: Dichotomy in Tail Distribution

    NASA Astrophysics Data System (ADS)

    Zhao, Chen; Sichitiu, Mihail L.

    Contact time (or link duration) is a fundamental factor that affects performance in Mobile Ad Hoc Networks. Previous research on theoretical analysis of contact time distribution for random walk models (RW) assume that the contact events can be modeled as either consecutive random walks or direct traversals, which are two extreme cases of random walk, thus with two different conclusions. In this paper we conduct a comprehensive research on this topic in the hope of bridging the gap between the two extremes. The conclusions from the two extreme cases will result in a power-law or exponential tail in the contact time distribution, respectively. However, we show that the actual distribution will vary between the two extremes: a power-law-sub-exponential dichotomy, whose transition point depends on the average flight duration. Through simulation results we show that such conclusion also applies to random waypoint.

  7. Building 865 Hypersonic Wind Tunnel Power System Analysis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schneider, Larry X.

    2015-02-01

    This report documents the characterization and analysis of a high current power supply for the building 865 Hypersonic Wind Tunnel at Sandia National Laboratories. The system described in this report became operational in 2013, replacing the original 1968 system which employed an induction voltage regulator. This analysis and testing was completed to help the parent organization understand why an updated and redesigned power system was not delivering adequate power to resistive heater elements in the HWT. This analysis led to an improved understanding of the design and operation of the revised 2013 power supply system and identifies several reasons themore » revised system failed to achieve the performance of the original power supply installation. Design modifications to improve the performance of this system are discussed.« less

  8. Power allocation and range performance considerations for a dual-frequency EBPSK/MPPSK system

    NASA Astrophysics Data System (ADS)

    Yao, Yu; Wu, Lenan; Zhao, Junhui

    2017-12-01

    Extended binary phase shift keying/M-ary position phase shift keying (EBPSK/MPPSK)-MODEM provides radar and communication functions on a single hardware platform with a single waveform. However, its range estimation accuracy is worse than continuous-wave (CW) radar because of the imbalance of power in two carrier frequencies. In this article, the power allocation method for dual-frequency EBPSK/MPPSK modulated systems is presented. The power of two signal transmitters is adequately allocated to ensure that the power in two carrier frequencies is equal. The power allocation ratios for two types of modulation systems are obtained. Moreover, considerations regarding the range of operation of the dual-frequency system are analysed. In addition to theoretical considerations, computer simulations are provided to illustrate the performance.

  9. Do randomized clinical trials with inadequate blinding report enhanced placebo effects for intervention groups and nocebo effects for placebo groups?

    PubMed Central

    2014-01-01

    Background Studies suggest that expectations powerfully shape clinical outcomes. For subjective outcomes in adequately blinded trials, health improvements are substantial and largely explained by non-specific factors. The objective of this study was to investigate if unblinding in randomized controlled trials (RCTs) is associated with enhanced placebo effects for intervention groups and nocebo effects for placebo groups. For these effects, a secondary objective was to explore potential moderating factors. Methods We included RCTs that investigated the efficacy of phosphodiesterase-5 (PDE-5) inhibitors for male erectile dysfunction by comparing one PDE-5 inhibitor to placebo. In addition, to be included studies must have reported scores for change from baseline, or baseline and final International Index of Erectile Functioning-Erectile Functioning domain score (IIEF-EF), and be published in either English, French, Dutch, or German. We searched for both published and unpublished relevant trials using PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials, a clinical trials register (clinicaltrials.gov) and the Food and Drug Administration clinical reviews through March 2012. We evaluated the blinding status of trials with the Cochrane Risk of Bias Tool, using the domains of allocation sequence concealment, blinding of participants, healthcare providers and outcome assessors. Across these four domains, studies that scored low risk of bias were judged to be adequately blinded and studies that scored unclear or high risk of bias were judged to be inadequately blinded. Results We included 110 studies (205 journal publications and 2 unpublished sources) that involved 23,877 participants; 93 (85%), 51 (46%), 93 (85%) and 93 (85%) studies were assessed with an unclear risk of bias for allocation concealment, blinding of participant, blinding of caregiver and blinding of outcome assessor, respectively. None of the studies reported testing of blinding. None of the 205 journal publications provided sufficient details to assess allocation concealment, blinding of participants, caregivers and outcome assessors. After contacting authors for additional information, we judged five studies to be adequately (n = 1,202) and 16 to be inadequately (n = 3,006) blinded. The IIEF-EF score for placebo groups in adequately blinded trials versus inadequately blinded trials was 1.92 points (95% CI, 0.64 to 3.20) versus 1.56 (95% CI, 0.93 to 2.20), respectively. The IIEF-EF score for intervention groups in adequately blinded trials versus inadequately blinded trials was 9.40 (95% CI, 6.96 to 11.83) versus 8.33 (95% CI, 7.29 to 9.37), respectively. In a secondary analysis, prior experience with the drug affected the scores; in placebo groups with participants naïve to the intervention the score was 2.89 (95% CI, 2.33 to 3.45) versus -0.11 (95% CI, -2.06 to 1.84) with participants having prior experience. In the intervention groups, these scores were 7.99 (95% CI, 6.85 to 9.14) versus 8.33 (95% CI, 7.51 to 9.16), respectively. Unblinding lowered placebo scores (creating a nocebo effect) by 19% (0.33 points; 95% CI, -0.96 to 1.62). Unblinding lowered intervention scores by 11% (1.0; 95% CI, -1.35 to 3.47). The results provided no conclusive evidence for nocebo or enhanced placebo effects. Patients taking a PDE-5 inhibitor for the first time experience a larger placebo effect that accounts for 35% of the total effect. Conclusions Given the overall poor reporting of blinding in clinical trial reports and the small number of trials that could be rated as adequately or inadequately blinded, we could not draw any robust conclusions about the existence or absence of nocebo and enhanced placebo effects. A large placebo effect was found for patients taking PDE-5 inhibitors for the first time. It was not clear if previous exposure to the drug impacted trial blinding. We found clear evidence that studies assessing a subjective continuous outcome fail to report on measures taken to secure double blinding. Although we observed a trend for the presence of a nocebo effect, there was insufficient evidence to quantify its impact on expectations. RCTs with patients with no prior experience with PDE-5 inhibitors reported larger placebo effects and possibly these studies were better blinded. Future research should further investigate the factors that contribute to blinding and their impact on health outcomes in randomized trials of subjectively assessed conditions. This research is part of a PhD project and has no external funding. The authors have no competing interests to declare. PMID:24555576

  10. The Bi-Directional Relationship between Parent-Child Conflict and Treatment Outcome in Treatment-Resistant Adolescent Depression

    ERIC Educational Resources Information Center

    Rengasamy, Manivel; Mansoor, Brandon M.; Hilton, Robert; Porta, Giovanna; He, Jiayan; Emslie, Graham J.; Mayes, Taryn; Clarke, Gregory N.; Wagner, Karen Dineen; Keller, Martin B.; Ryan, Neal D.; Birmaher, Boris; Shamseddeen, Wael; Asarnow, Joan Rosenbaum; Brent, David A.

    2013-01-01

    Objective: To examine the bidirectional relationship between parent-child discord and treatment outcome for adolescent treatment-resistant depression. Method: Depressed youth who had not responded to an adequate course of a selective serotonin reuptake inhibitor (SSRI) were randomized to either a switch to another SSRI or venlafaxine, with or…

  11. Nonlinear Image Denoising Methodologies

    DTIC Science & Technology

    2002-05-01

    53 5.3 A Multiscale Approach to Scale-Space Analysis . . . . . . . . . . . . . . . . 53 5.4...etc. In this thesis, Our approach to denoising is first based on a controlled nonlinear stochastic random walk to achieve a scale space analysis ( as in... stochastic treatment or interpretation of the diffusion. In addition, unless a specific stopping time is known to be adequate, the resulting evolution

  12. 7 CFR 1710.208 - RUS criteria for approval of all load forecasts by power supply borrowers and by distribution...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... borrower developed an adequate supporting database and analyzed a reasonable range of relevant assumptions and alternative futures; (d) The borrower adopted methods and procedures in general use by the...

  13. POWERS forID: Personalized Online Weight and Exercise Response System for Individuals with Intellectual Disability: study protocol for a randomized controlled trial.

    PubMed

    Neumeier, William H; Guerra, Nichole; Thirumalai, Mohanraj; Geer, Betty; Ervin, David; Rimmer, James H

    2017-10-23

    Intellectual disability (ID) is characterized by limitations in intellectual functioning and adaptive behavior. Adults with ID exhibit higher rates of obesity and poorer health status compared to the general population. Continuity of care and barriers to health-related activities may contribute to the poorer health status observed in this population. To address this problem, a tailored weight management online health information and communication technology platform, known as POWERS forID , was developed and is being tested to determine if this delivery mechanism can improve weight maintenance/weight loss in adults with ID. Obese adults with mild-to-moderate ID (n = 70) are randomized to the POWERS forID intervention or control group for a 24-week trial. Each group undergoes an assessment that includes body weight, waist circumference, and percent body fat at baseline and at weeks 6, 12, and 24. Physical activity barriers, healthy eating barriers, food frequency, and psychosocial wellbeing are measured at baseline and at weeks 12 and 24. Blood lipids are assessed at baseline and 24 weeks. Participants randomized to POWERS forID receive access to the POWERS forID website and calls from a health coach (weekly during weeks 1-12, biweekly during weeks 13-24). The health coach employs motivational interviewing techniques adapted for individuals with ID to promote behavior change. Participants randomized to the control group receive standard clinical weight-loss care. Differences in weight, waist circumference, blood lipids, percent body fat, and psychosocial self-report will be assessed. Barriers and facilitators of implementation as well as perception of study outcomes will be conducted via qualitative analysis. POWERS forID is a novel information and communication technology platform designed to address health needs for adults with ID. This article describes the development and components of POWERS forID . The overall aim is to assess usability and feasibility of POWERS forID for promoting weight loss for obese adults with ID over the course of a 24-week randomized control trial. Clinicaltrials.gov, NCT03139760 . Registered on XXX.

  14. Assessment of Power Potential of Tidal Currents and Impacts of Power Extraction on Flow Speeds in Indonesia

    NASA Astrophysics Data System (ADS)

    Orhan, K.; Mayerle, R.

    2016-12-01

    A methodology comprising of the estimates of power yield, evaluation of the effects of power extraction on flow conditions, and near-field investigations to deliver wake characteritics, recovery and interactions is described and applied to several straits in Indonesia. Site selection is done with high-resolution, three-dimensional flow models providing sufficient spatiotemporal coverage. Much attention has been given to the meteorological forcing, and conditions at the open sea boundaries to adequately capture the density gradients and flow fields. Model verification using tidal records shows excellent agreement. Sites with adequate depth for the energy conversion using horizontal axis tidal turbines, average kinetic power density greater than 0.5 kW/m2, and surface area larger than 0.5km2 are defined as energy hotspots. Spatial variation of the average extractable electric power is determined, and annual tidal energy resource is estimated for the straits in question. The results showed that the potential for tidal power generation in Indonesia is likely to exceed previous predictions reaching around 4,800MW. To assess the impact of the devices, flexible mesh models with higher resolutions have been developed. Effects on flow conditions, and near-field turbine wakes are resolved in greater detail with triangular horizontal grids. The energy is assumed to be removed uniformly by sub-grid scale arrays of turbines, and calculations are made based on velocities at the hub heights of the devices. An additional drag force resulting in dissipation of the pre-existing kinetic power from %10 to %60 within a flow cross-section is introduced to capture the impacts. It was found that the effect of power extraction on water levels and flow speeds in adjacent areas is not significant. Results show the effectivess of the method to capture wake characteritics and recovery reasonably well with low computational cost.

  15. Supplementation during pregnancy with small-quantity lipid-based nutrient supplements or multiple micronutrients, compared with iron and folic acid, increases women's urinary iodine concentration in semiurban Ghana: A randomized controlled trial.

    PubMed

    Adu-Afarwuah, Seth; Young, Rebecca T; Lartey, Anna; Okronipa, Harriet; Ashorn, Per; Ashorn, Ulla; Zeilani, Mamane; Dewey, Kathryn G

    2018-04-01

    There is little information on whether prenatal multiple micronutrient (MMN) supplements containing iodine affect women's iodine status. In the International Lipid-based Nutrient Supplements DYAD-Ghana trial, we aimed to assess women's urinary iodine concentration (UIC, μg/L) during pregnancy, as one of the planned secondary outcomes. Women (n = 1,320) <20 weeks of gestation were randomized to consume 60 mg iron and 400 μg folic acid per day (iron and folic acid [IFA]); 18 vitamins and minerals including 250 μg iodine per day (MMN); or 20 g/day of small-quantity lipid-based nutrient supplements (LNS) with the same and additional 4 vitamins and minerals as the MMN (LNS). In a subsample (n = 295), we tested differences in groups' geometric mean UICs at 36 weeks of gestation controlling for baseline UIC and compared the geometric means (approximately median UICs) with the World Health Organization (WHO) cut-offs: median UIC <150, 150-249, and ≥500 reflecting low, adequate, and excessive iodine intakes, respectively. At baseline, overall median UIC was 137. At 36 weeks of gestation, controlling for baseline UIC, geometric mean (95% confidence interval) UICs of the MMN (161 [133, 184]) and LNS (158 [132, 185]) groups did not differ; both values were significantly greater (overall p = .004) than that of the IFA group (116 [101, 135]). The median UICs of the MMN and LNS groups were within the WHO "adequate" range, whereas that of the IFA group was below the WHO adequate range. In this setting, supplementation during pregnancy with small-quantity LNS or MMN providing iodine at the WHO-recommended dose, compared with IFA, increases the likelihood of adequate iodine status. © 2017 The Authors. Maternal & Child Nutrition published by John Wiley & Sons, Ltd.

  16. Far field beam pattern of one MW combined beam of laser diode array amplifiers for space power transmission

    NASA Technical Reports Server (NTRS)

    Kwon, Jin H.; Lee, Ja H.

    1989-01-01

    The far-field beam pattern and the power-collection efficiency are calculated for a multistage laser-diode-array amplifier consisting of about 200,000 5-W laser diode arrays with random distributions of phase and orientation errors and random diode failures. From the numerical calculation it is found that the far-field beam pattern is little affected by random failures of up to 20 percent of the laser diodes with reference of 80 percent receiving efficiency in the center spot. The random differences in phases among laser diodes due to probable manufacturing errors is allowed to about 0.2 times the wavelength. The maximum allowable orientation error is about 20 percent of the diffraction angle of a single laser diode aperture (about 1 cm). The preliminary results indicate that the amplifier could be used for space beam-power transmission with an efficiency of about 80 percent for a moderate-size (3-m-diameter) receiver placed at a distance of less than 50,000 km.

  17. Traceable measurements of the electrical parameters of solid-state lighting products

    NASA Astrophysics Data System (ADS)

    Zhao, D.; Rietveld, G.; Braun, J.-P.; Overney, F.; Lippert, T.; Christensen, A.

    2016-12-01

    In order to perform traceable measurements of the electrical parameters of solid-state lighting (SSL) products, it is necessary to technically adequately define the measurement procedures and to identify the relevant uncertainty sources. The present published written standard for SSL products specifies test conditions, but it lacks an explanation of how adequate these test conditions are. More specifically, both an identification of uncertainty sources and a quantitative uncertainty analysis are absent. This paper fills the related gap in the present written standard. New uncertainty sources with respect to conventional lighting sources are determined and their effects are quantified. It shows that for power measurements, the main uncertainty sources are temperature deviation, power supply voltage distortion, and instability of the SSL product. For current RMS measurements, the influence of bandwidth, shunt resistor, power supply source impedance and ac frequency flatness are significant as well. The measurement uncertainty depends not only on the test equipment but is also a function of the characteristics of the device under test (DUT), for example, current harmonics spectrum and input impedance. Therefore, an online calculation tool is provided to help non-electrical experts. Following our procedures, unrealistic uncertainty estimations, unnecessary procedures and expensive equipment can be prevented.

  18. Comparison of existing digital image analysis systems for the analysis of Thematic Mapper data

    NASA Technical Reports Server (NTRS)

    Likens, W. C.; Wrigley, R. C.

    1984-01-01

    Most existing image analysis systems were designed with the Landsat Multi-Spectral Scanner in mind, leaving open the question of whether or not these systems could adequately process Thematic Mapper data. In this report, both hardware and software systems have been evaluated for compatibility with TM data. Lack of spectral analysis capability was not found to be a problem, though techniques for spatial filtering and texture varied. Computer processing speed and data storage of currently existing mini-computer based systems may be less than adequate. Upgrading to more powerful hardware may be required for many TM applications.

  19. A randomized, placebo-controlled proof-of-concept trial of adjunctive topiramate for alcohol use disorders in bipolar disorder.

    PubMed

    Sylvia, Louisa G; Gold, Alexandra K; Stange, Jonathan P; Peckham, Andrew D; Deckersbach, Thilo; Calabrese, Joseph R; Weiss, Roger D; Perlis, Roy H; Nierenberg, Andrew A; Ostacher, Michael J

    2016-03-01

    Topiramate is effective for alcohol use disorders (AUDs) among non-psychiatric patients. We examined topiramate for treating comorbid AUDs in bipolar disorder (BD). Twelve participants were randomized to topiramate or placebo for 12 weeks. The topiramate group, with two out of five participants (40%) completing treatment, experienced less improvement in drinking patterns than the placebo group, with five out of seven participants (71%) completing treatment. Topiramate did not improve drinking behavior and was not well-tolerated. This study failed to recruit adequately. Problems surrounding high attrition, a small study sample, and missing data preclude interpretation of study findings. This is the first randomized, placebo-controlled trial of topiramate for AUDs in BD. © American Academy of Addiction Psychiatry.

  20. Power technologies and the space future

    NASA Technical Reports Server (NTRS)

    Faymon, Karl A.; Fordyce, J. Stuart; Brandhorst, Henry W., Jr.

    1991-01-01

    Advancements in space power and energy technologies are critical to serve space development needs and help solve problems on Earth. The availability of low cost power and energy in space will be the hallmark of this advance. Space power will undergo a dramatic change for future space missions. The power systems which have served the U.S. space program so well in the past will not suffice for the missions of the future. This is especially true if the space commercialization is to become a reality. New technologies, and new and different space power architectures and topologies will replace the lower power, low-voltage systems of the past. Efficiencies will be markedly improved, specific powers will be greatly increased, and system lifetimes will be markedly extended. Space power technology is discussed - its past, its current status, and predictions about where it will go in the future. A key problem for power and energy is its cost of affordability. Power must be affordable or it will not serve future needs adequately. This aspect is also specifically addressed.

  1. Evaluation of participant comprehension of information received in an exercise and diet intervention trial: The DR's EXTRA study.

    PubMed

    Länsimies-Antikainen, Helena; Pietilä, Anna-Maija; Kiviniemi, Vesa; Rauramaa, Rainer; Laitinen, Tomi

    2010-01-01

    The informed consent process is the legal and ethical cornerstone of health research and is essential to ensure that participants in health research really understand the information they receive. Clinical studies often fail to provide data that clarify how much participants have understood. To evaluate the comprehension of older volunteer participants in health research. The subjects are a random population sample of 1,410 men and women aged 57-78 years, who are participating in a 4-year randomized controlled intervention trial on the effects of physical exercise and diet on atherosclerosis, endothelial function and cognition. A questionnaire about informed consent was given to all willing participants (n = 1,324) 3 months after the randomization. In addition, participants' long-term continuation in the intervention trial with relation to understanding was evaluated 2 years after the randomization. The response rate was 91%. The majority of respondents (89%) were satisfied with the intelligibility of received information. In addition, the participants' comprehension of the information received seemed to be adequate in 82% of the whole study population. Compared to background variables, higher education (p < 0.001) and satisfaction with one's own health (p = 0.01) were associated with adequate comprehension of the provided information. Furthermore, participants who felt themselves to be healthy were more likely to continue participating in the intervention after 2 years. The findings of this study indicated sufficient understanding of received information in older research participants. However, our results indicate that special efforts should be made with participants with lower educational levels or subjective feelings of impaired health. This study highlights the need for researchers to critically analyze the quality of information and how it is provided. This is especially important in long-term follow-up studies. 2009 S. Karger AG, Basel.

  2. Factors associated with adequate weekly reporting for disease surveillance data among health facilities in Nairobi County, Kenya, 2013.

    PubMed

    Mwatondo, Athman Juma; Ng'ang'a, Zipporah; Maina, Caroline; Makayotto, Lyndah; Mwangi, Moses; Njeru, Ian; Arvelo, Wences

    2016-01-01

    Kenya adopted the Integrated Disease Surveillance and Response (IDSR) strategy in 1998 to strengthen disease surveillance and epidemic response. However, the goal of weekly surveillance reporting among health facilities has not been achieved. We conducted a cross-sectional study to determine the prevalence of adequate reporting and factors associated with IDSR reporting among health facilities in one Kenyan County. Health facilities (public and private) were enrolled using stratified random sampling from 348 facilities prioritized for routine surveillance reporting. Adequately-reporting facilities were defined as those which submitted >10 weekly reports during a twelve-week period and a poor reporting facilities were those which submitted <10 weekly reports. Multivariate logistic regression with backward selection was used to identify risk factors associated with adequate reporting. From September 2 through November 30, 2013, we enrolled 175 health facilities; 130(74%) were private and 45(26%) were public. Of the 175 health facilities, 77 (44%) facilities classified as adequate reporting and 98 (56%) were reporting poorly. Multivariate analysis identified three factors to be independently associated with weekly adequate reporting: having weekly reporting forms at visit (AOR19, 95% CI: 6-65], having posters showing IDSR functions (AOR8, 95% CI: 2-12) and having a designated surveillance focal person (AOR7, 95% CI: 2-20). The majority of health facilities in Nairobi County were reporting poorly to IDSR and we recommend that the Ministry of Health provide all health facilities in Nairobi County with weekly reporting tools and offer specific trainings on IDSR which will help designate a focal surveillance person.

  3. Sample size requirements for separating out the effects of combination treatments: randomised controlled trials of combination therapy vs. standard treatment compared to factorial designs for patients with tuberculous meningitis.

    PubMed

    Wolbers, Marcel; Heemskerk, Dorothee; Chau, Tran Thi Hong; Yen, Nguyen Thi Bich; Caws, Maxine; Farrar, Jeremy; Day, Jeremy

    2011-02-02

    In certain diseases clinical experts may judge that the intervention with the best prospects is the addition of two treatments to the standard of care. This can either be tested with a simple randomized trial of combination versus standard treatment or with a 2 x 2 factorial design. We compared the two approaches using the design of a new trial in tuberculous meningitis as an example. In that trial the combination of 2 drugs added to standard treatment is assumed to reduce the hazard of death by 30% and the sample size of the combination trial to achieve 80% power is 750 patients. We calculated the power of corresponding factorial designs with one- to sixteen-fold the sample size of the combination trial depending on the contribution of each individual drug to the combination treatment effect and the strength of an interaction between the two. In the absence of an interaction, an eight-fold increase in sample size for the factorial design as compared to the combination trial is required to get 80% power to jointly detect effects of both drugs if the contribution of the less potent treatment to the total effect is at least 35%. An eight-fold sample size increase also provides a power of 76% to detect a qualitative interaction at the one-sided 10% significance level if the individual effects of both drugs are equal. Factorial designs with a lower sample size have a high chance to be underpowered, to show significance of only one drug even if both are equally effective, and to miss important interactions. Pragmatic combination trials of multiple interventions versus standard therapy are valuable in diseases with a limited patient pool if all interventions test the same treatment concept, it is considered likely that either both or none of the individual interventions are effective, and only moderate drug interactions are suspected. An adequately powered 2 x 2 factorial design to detect effects of individual drugs would require at least 8-fold the sample size of the combination trial. Current Controlled Trials ISRCTN61649292.

  4. Reliability and economy -- Hydro electricity for Iran

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jahromi-Shirazi, M.J.; Zarbakhsh, M.H.

    1998-12-31

    Reliability is the probability that a device or system will perform its function adequately, for the period of time intended, under the operating conditions intended. Reliability and economy are two important factors in operating any system, especially in power generation. Due to the high rate in population growth in Iran, the experts have estimated that the demand for electricity will be about 63,000 MW in the next 25 years, the installed power is now about 26,000 MW. Therefore, the energy policy decision made in Iran is to go to power generation by hydroelectric plants because of reliability, availability of watermore » resources and the economics of hydroelectric power.« less

  5. Bayesian network meta-analysis for cluster randomized trials with binary outcomes.

    PubMed

    Uhlmann, Lorenz; Jensen, Katrin; Kieser, Meinhard

    2017-06-01

    Network meta-analysis is becoming a common approach to combine direct and indirect comparisons of several treatment arms. In recent research, there have been various developments and extensions of the standard methodology. Simultaneously, cluster randomized trials are experiencing an increased popularity, especially in the field of health services research, where, for example, medical practices are the units of randomization but the outcome is measured at the patient level. Combination of the results of cluster randomized trials is challenging. In this tutorial, we examine and compare different approaches for the incorporation of cluster randomized trials in a (network) meta-analysis. Furthermore, we provide practical insight on the implementation of the models. In simulation studies, it is shown that some of the examined approaches lead to unsatisfying results. However, there are alternatives which are suitable to combine cluster randomized trials in a network meta-analysis as they are unbiased and reach accurate coverage rates. In conclusion, the methodology can be extended in such a way that an adequate inclusion of the results obtained in cluster randomized trials becomes feasible. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. STS/DBS power subsystem end-to-end stability margin

    NASA Astrophysics Data System (ADS)

    Devaux, R. N.; Vattimo, R. J.; Peck, S. R.; Baker, W. E.

    Attention is given to a full-up end-to-end subsystem stability test which was performed with a flight solar array providing power to a fully operational spacecraft. The solar array simulator is described, and a comparison is made between test results obtained with the simulator and those obtained with the actual array. It is concluded that stability testing with a fully integrated spacecraft is necessary to ensure that all elements have been adequately modeled.

  7. Laser-Powered Thrusters for High Efficiency Variable Specific Impulse Missions (Preprint)

    DTIC Science & Technology

    2007-04-10

    technology. However, a laser-ablation propulsion engine using a set of diode-pumped glass fiber amplifiers with a total of 350-W optical power can...in a single device using low-mass diode-pumped glass fiber laser amplifiers to operate in either long- or short-pulse regimes at will. Adequate fiber...pulsewidth glass fiber oscillator-amplifiers, rather than the diodes used in the µ LPT, to achieve Table 2. Demonstrated technology basis Ablation Fuel Gold

  8. Informing Estimates of Program Effects for Studies of Mathematics Professional Development Using Teacher Content Knowledge Outcomes.

    PubMed

    Phelps, Geoffrey; Kelcey, Benjamin; Jones, Nathan; Liu, Shuangshuang

    2016-10-03

    Mathematics professional development is widely offered, typically with the goal of improving teachers' content knowledge, the quality of teaching, and ultimately students' achievement. Recently, new assessments focused on mathematical knowledge for teaching (MKT) have been developed to assist in the evaluation and improvement of mathematics professional development. This study presents empirical estimates of average program change in MKT and its variation with the goal of supporting the design of experimental trials that are adequately powered to detect a specified program effect. The study drew on a large database representing five different assessments of MKT and collectively 326 professional development programs and 9,365 teachers. Results from cross-classified hierarchical growth models found that standardized average change estimates across the five assessments ranged from a low of 0.16 standard deviations (SDs) to a high of 0.26 SDs. Power analyses using the estimated pre- and posttest change estimates indicated that hundreds of teachers are needed to detect changes in knowledge at the lower end of the distribution. Even studies powered to detect effects at the higher end of the distribution will require substantial resources to conduct rigorous experimental trials. Empirical benchmarks that describe average program change and its variation provide a useful preliminary resource for interpreting the relative magnitude of effect sizes associated with professional development programs and for designing adequately powered trials. © The Author(s) 2016.

  9. Why Does Trigonometric Substitution Work?

    ERIC Educational Resources Information Center

    Cunningham, Daniel W.

    2018-01-01

    Modern calculus textbooks carefully illustrate how to perform integration by trigonometric substitution. Unfortunately, most of these books do not adequately justify this powerful technique of integration. In this article, we present an accessible proof that establishes the validity of integration by trigonometric substitution. The proof offers…

  10. Low-order black-box models for control system design in large power systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kamwa, I.; Trudel, G.; Gerin-Lajoie, L.

    1996-02-01

    The paper studies two multi-input multi-output (MIMO) procedures for the identification of low-order state-space models of power systems, by probing the network in open loop with low-energy pulses or random signals. Although such data may result from actual measurements, the development assumes simulated responses from a transient stability program, hence benefiting from the existing large base of stability models. While pulse data is processed using the eigensystem realization algorithm, the analysis of random responses is done by means of subspace identification methods. On a prototype Hydro-Quebec power system, including SVCs, DC lines, series compensation, and more than 1,100 buses, itmore » is verified that the two approaches are equivalent only when strict requirements are imposed on the pulse length and magnitude. The 10th-order equivalent models derived by random-signal probing allow for effective tuning of decentralized power system stabilizers (PSSs) able to damp both local and very slow inter-area modes.« less

  11. Low-order black-box models for control system design in large power systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kamwa, I.; Trudel, G.; Gerin-Lajoie, L.

    1995-12-31

    The paper studies two multi-input multi-output (MIMO) procedures for the identification of low-order state-space models of power systems, by probing the network in open loop with low-energy pulses or random signals. Although such data may result from actual measurements, the development assumes simulated responses from a transient stability program, hence benefiting form the existing large base of stability models. While pulse data is processed using the eigensystem realization algorithm, the analysis of random responses is done by means of subspace identification methods. On a prototype Hydro-Quebec power system, including SVCs, DC lines, series compensation, and more than 1,100 buses, itmore » is verified that the two approaches are equivalent only when strict requirements are imposed on the pulse length and magnitude. The 10th-order equivalent models derived by random-signal probing allow for effective tuning of decentralized power system stabilizers (PSSs) able to damp both local and very slow inter-area modes.« less

  12. Pharmacotherapy of Hypertension in Chronic Dialysis Patients

    PubMed Central

    Georgianos, Panagiotis I.

    2016-01-01

    Among patients on dialysis, hypertension is highly prevalent and contributes to the high burden of cardiovascular morbidity and mortality. Strict volume control via sodium restriction and probing of dry weight are first-line approaches for the treatment of hypertension in this population; however, antihypertensive drug therapy is often needed to control BP. Few trials compare head-to-head the superiority of one antihypertensive drug class over another with respect to improving BP control or altering cardiovascular outcomes; accordingly, selection of the appropriate antihypertensive regimen should be individualized. To individualize therapy, consideration should be given to intra- and interdialytic pharmacokinetics, effect on cardiovascular reflexes, ability to treat comorbid illnesses, and adverse effect profile. β-Blockers followed by dihydropyridine calcium-channel blockers are our first- and second-line choices for antihypertensive drug use. Angiotensin–converting enzyme inhibitors and angiotensin receptor blockers seem to be reasonable third–line choices, because the evidence base to support their use in patients on dialysis is sparse. Add-on therapy with mineralocorticoid receptor antagonists in specific subgroups of patients on dialysis (i.e., those with severe congestive heart failure) seems to be another promising option in anticipation of the ongoing trials evaluating their efficacy and safety. Adequately powered, multicenter, randomized trials evaluating hard cardiovascular end points are urgently warranted to elucidate the comparative effectiveness of antihypertensive drug classes in patients on dialysis. In this review, we provide an overview of the randomized evidence on pharmacotherapy of hypertension in patients on dialysis, and we conclude with suggestions for future research to address critical gaps in this important area. PMID:27797886

  13. A home-based exercise program to improve function, fatigue, and sleep quality in patients with Stage IV lung and colorectal cancer: a randomized controlled trial.

    PubMed

    Cheville, Andrea L; Kollasch, Jenny; Vandenberg, Justin; Shen, Tiffany; Grothey, Axel; Gamble, Gail; Basford, Jeffrey R

    2013-05-01

    Exercise benefits patients with cancer, but studies of home-based approaches, particularly among those with Stage IV disease, remain small and exploratory. To conduct an adequately powered trial of a home-based exercise intervention that can be facilely integrated into established delivery and reimbursement structures. Sixty-six adults with Stage IV lung or colorectal cancer were randomized, in an eight-week trial, to usual care or incremental walking and home-based strength training. The exercising participants were instructed during a single physiotherapy visit and subsequently exercised four days or more per week; training and step-count goals were advanced during bimonthly telephone calls. The primary outcome measure was mobility assessed with the Ambulatory Post Acute Care Basic Mobility Short Form. Secondary outcomes included ratings of pain and sleep quality as well as the ability to perform daily activities (Ambulatory Post Acute Care Daily Activities Short Form), quality of life (Functional Assessment of Cancer Therapy-General), and fatigue (Functional Assessment of Cancer Therapy-Fatigue). Three participants dropped out and seven died (five in the intervention and two in the control group, P=0.28). At Week 8, the intervention group reported improved mobility (P=0.01), fatigue (P=0.02), and sleep quality (P=0.05) compared with the usual care group, but did not differ on the other measures. A home-based exercise program seems capable of improving the mobility, fatigue, and sleep quality of patients with Stage IV lung and colorectal cancer. Copyright © 2013. Published by Elsevier Inc.

  14. [A Decade of Online Physician-Rating Websites in Germany: an Assessment of the Current Level of Development].

    PubMed

    Emmert, Martin; Meszmer, Nina

    2017-07-31

    Objective On physician-rating websites (PRW), patients have the opportunity to search for physicians and also evaluate their performance. PRW in Germany has been in existence for a decade; this study aims to provide an overview of the current level of their significance for both patients and the health care system. Methods (1) A systematic internet search was carried out to identify German PRW. (2) Online-derived cross-sectional data (N=1,044 respondents) were analyzed with respect to awareness, usage, and impact of PRW as well as patient preferences when searching online for physicians. (3) An analysis of the structure of online ratings for a random sample of 11% of German dermatologists was conducted. Results In total, we identified 29 PRWs. Slightly more than half of all respondents (54%) were aware of German PRW and every fourth respondent has already used PRW to search for a physician. Approximately 70% of all users stated they had already made a decision for or against a particular physician based on the quality ratings shown on PRW. Almost all dermatologists could be identified on PRW and 93% have already been rated on any PRW (mean number of ratings: 24.55). More than half of all ratings (55%) were positive. Conclusion After one decade of development, PRWs seem to have gained significant importance in the German health care sector. However, high-quality and adequately powered randomized controlled trials are required to determine the impact of PRWs on patient steerage. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Succinylcholine versus rocuronium for rapid sequence intubation in intensive care: a prospective, randomized controlled trial

    PubMed Central

    2011-01-01

    Introduction Succinylcholine and rocuronium are widely used to facilitate rapid sequence induction (RSI) intubation in intensive care. Concerns relate to the side effects of succinylcholine and to slower onset and inferior intubation conditions associated with rocuronium. So far, succinylcholine and rocuronium have not been compared in an adequately powered randomized trial in intensive care. Accordingly, the aim of the present study was to compare the incidence of hypoxemia after rocuronium or succinylcholine in critically ill patients requiring an emergent RSI. Methods This was a prospective randomized controlled single-blind trial conducted from 2006 to 2010 at the University Hospital of Basel. Participants were 401 critically ill patients requiring emergent RSI. Patients were randomized to receive 1 mg/kg succinylcholine or 0.6 mg/kg rocuronium for neuromuscular blockade. The primary outcome was the incidence of oxygen desaturations defined as a decrease in oxygen saturation ≥ 5%, assessed by continuous pulse oxymetry, at any time between the start of the induction sequence and two minutes after the completion of the intubation. A severe oxygen desaturation was defined as a decrease in oxygen saturation ≥ 5% leading to a saturation value of ≤ 80%. Results There was no difference between succinylcholine and rocuronium regarding oxygen desaturations (succinylcholine 73/196; rocuronium 66/195; P = 0.67); severe oxygen desaturations (succinylcholine 20/196; rocuronium 20/195; P = 1.0); and extent of oxygen desaturations (succinylcholine -14 ± 12%; rocuronium -16 ± 13%; P = 0.77). The duration of the intubation sequence was shorter after succinycholine than after rocuronium (81 ± 38 sec versus 95 ± 48 sec; P = 0.002). Intubation conditions (succinylcholine 8.3 ± 0.8; rocuronium 8.2 ± 0.9; P = 0.7) and failed first intubation attempts (succinylcholine 32/200; rocuronium 36/201; P = 1.0) did not differ between the groups. Conclusions In critically ill patients undergoing emergent RSI, incidence and severity of oxygen desaturations, the quality of intubation conditions, and incidence of failed intubation attempts did not differ between succinylcholine and rocuronium. Trial Registration ClinicalTrials.gov, number NCT00355368. PMID:21846380

  16. Positive Effect of Probiotics on Constipation in Children: A Systematic Review and Meta-Analysis of Six Randomized Controlled Trials

    PubMed Central

    Huang, Ruixue; Hu, Jianan

    2017-01-01

    Context: Constipation in children is a prevalent, burdensome, and psychologically important pediatric issue, the treatment of which remains a global challenge. The use of probiotics has been reported for management of the gastrointestinal microbiota. Objective: This study reviewed the existing literatures of 6 Randomized Control Trials (RCTs) to ascertain some baseline understanding and available information for the effects of probiotics on stool frequency and consistency in children with constipation. Data Sources: PubMed, Springer, Elsevier Science, Cochrane Library, Scopus, Ovid (Medline, EMBASE, PsycINFO), Orbis, and Web of Science from the earliest record in each database to 15 September, 2016. Study selection: Eligible studies were randomized controlled trials that compared the effect of probiotics interventions to any control intervention on stool frequency and consistency. Data Extraction: Studies were identified by searching electronic databases. The meta-analysis was performed by Review Manager 5.3 software using a randomized model. Results: Six studies were identified. The use of probiotics significantly increased the stool frequency [mean difference (MD), 0.73; 95% confidence interval (CI), 0.14–1.31; P = 0.02]. Subgroup assessment showed a significantly increased stool frequency in Asian patients (MD, 1.18; 95% CI, 0.33–2.02; P = 0.006), but no significant difference in stool consistency (MD, −0.07; 95% CI, −0.21–0.06; P = 0.27). Limitations: Only six RCTs met the criteria and were included. Each RCT in this study was performed in a different country, and some of the included studies had a small sample size, which might have influenced the reliability and validity of the conclusions. Conclusion: The present study shows that probiotics increase stool frequency and have beneficial effects in Asian children. However, caution is needed when interpreting these outcomes because of the existence of heterogeneity. Evidence from larger samples and more adequately powered RCTs with results obtained by standardized measurements are necessary to determine which species and dosage of probiotics and what length of treatment are most efficacious for constipation in children. PMID:28503492

  17. Positive Effect of Probiotics on Constipation in Children: A Systematic Review and Meta-Analysis of Six Randomized Controlled Trials.

    PubMed

    Huang, Ruixue; Hu, Jianan

    2017-01-01

    Context: Constipation in children is a prevalent, burdensome, and psychologically important pediatric issue, the treatment of which remains a global challenge. The use of probiotics has been reported for management of the gastrointestinal microbiota. Objective: This study reviewed the existing literatures of 6 Randomized Control Trials (RCTs) to ascertain some baseline understanding and available information for the effects of probiotics on stool frequency and consistency in children with constipation. Data Sources: PubMed, Springer, Elsevier Science, Cochrane Library, Scopus, Ovid (Medline, EMBASE, PsycINFO), Orbis, and Web of Science from the earliest record in each database to 15 September, 2016. Study selection: Eligible studies were randomized controlled trials that compared the effect of probiotics interventions to any control intervention on stool frequency and consistency. Data Extraction: Studies were identified by searching electronic databases. The meta-analysis was performed by Review Manager 5.3 software using a randomized model. Results: Six studies were identified. The use of probiotics significantly increased the stool frequency [mean difference (MD), 0.73; 95% confidence interval (CI), 0.14-1.31; P = 0.02]. Subgroup assessment showed a significantly increased stool frequency in Asian patients (MD, 1.18; 95% CI, 0.33-2.02; P = 0.006), but no significant difference in stool consistency (MD, -0.07; 95% CI, -0.21-0.06; P = 0.27). Limitations: Only six RCTs met the criteria and were included. Each RCT in this study was performed in a different country, and some of the included studies had a small sample size, which might have influenced the reliability and validity of the conclusions. Conclusion: The present study shows that probiotics increase stool frequency and have beneficial effects in Asian children. However, caution is needed when interpreting these outcomes because of the existence of heterogeneity. Evidence from larger samples and more adequately powered RCTs with results obtained by standardized measurements are necessary to determine which species and dosage of probiotics and what length of treatment are most efficacious for constipation in children.

  18. Transferability of optimally-selected climate models in the quantification of climate change impacts on hydrology

    NASA Astrophysics Data System (ADS)

    Chen, Jie; Brissette, François P.; Lucas-Picher, Philippe

    2016-11-01

    Given the ever increasing number of climate change simulations being carried out, it has become impractical to use all of them to cover the uncertainty of climate change impacts. Various methods have been proposed to optimally select subsets of a large ensemble of climate simulations for impact studies. However, the behaviour of optimally-selected subsets of climate simulations for climate change impacts is unknown, since the transfer process from climate projections to the impact study world is usually highly non-linear. Consequently, this study investigates the transferability of optimally-selected subsets of climate simulations in the case of hydrological impacts. Two different methods were used for the optimal selection of subsets of climate scenarios, and both were found to be capable of adequately representing the spread of selected climate model variables contained in the original large ensemble. However, in both cases, the optimal subsets had limited transferability to hydrological impacts. To capture a similar variability in the impact model world, many more simulations have to be used than those that are needed to simply cover variability from the climate model variables' perspective. Overall, both optimal subset selection methods were better than random selection when small subsets were selected from a large ensemble for impact studies. However, as the number of selected simulations increased, random selection often performed better than the two optimal methods. To ensure adequate uncertainty coverage, the results of this study imply that selecting as many climate change simulations as possible is the best avenue. Where this was not possible, the two optimal methods were found to perform adequately.

  19. How large are the consequences of covariate imbalance in cluster randomized trials: a simulation study with a continuous outcome and a binary covariate at the cluster level.

    PubMed

    Moerbeek, Mirjam; van Schie, Sander

    2016-07-11

    The number of clusters in a cluster randomized trial is often low. It is therefore likely random assignment of clusters to treatment conditions results in covariate imbalance. There are no studies that quantify the consequences of covariate imbalance in cluster randomized trials on parameter and standard error bias and on power to detect treatment effects. The consequences of covariance imbalance in unadjusted and adjusted linear mixed models are investigated by means of a simulation study. The factors in this study are the degree of imbalance, the covariate effect size, the cluster size and the intraclass correlation coefficient. The covariate is binary and measured at the cluster level; the outcome is continuous and measured at the individual level. The results show covariate imbalance results in negligible parameter bias and small standard error bias in adjusted linear mixed models. Ignoring the possibility of covariate imbalance while calculating the sample size at the cluster level may result in a loss in power of at most 25 % in the adjusted linear mixed model. The results are more severe for the unadjusted linear mixed model: parameter biases up to 100 % and standard error biases up to 200 % may be observed. Power levels based on the unadjusted linear mixed model are often too low. The consequences are most severe for large clusters and/or small intraclass correlation coefficients since then the required number of clusters to achieve a desired power level is smallest. The possibility of covariate imbalance should be taken into account while calculating the sample size of a cluster randomized trial. Otherwise more sophisticated methods to randomize clusters to treatments should be used, such as stratification or balance algorithms. All relevant covariates should be carefully identified, be actually measured and included in the statistical model to avoid severe levels of parameter and standard error bias and insufficient power levels.

  20. "Using Power Tables to Compute Statistical Power in Multilevel Experimental Designs"

    ERIC Educational Resources Information Center

    Konstantopoulos, Spyros

    2009-01-01

    Power computations for one-level experimental designs that assume simple random samples are greatly facilitated by power tables such as those presented in Cohen's book about statistical power analysis. However, in education and the social sciences experimental designs have naturally nested structures and multilevel models are needed to compute the…

  1. [Errors in Peruvian medical journals references].

    PubMed

    Huamaní, Charles; Pacheco-Romero, José

    2009-01-01

    References are fundamental in our studies; an adequate selection is asimportant as an adequate description. To determine the number of errors in a sample of references found in Peruvian medical journals. We reviewed 515 scientific papers references selected by systematic randomized sampling and corroborated reference information with the original document or its citation in Pubmed, LILACS or SciELO-Peru. We found errors in 47,6% (245) of the references, identifying 372 types of errors; the most frequent were errors in presentation style (120), authorship (100) and title (100), mainly due to spelling mistakes (91). References error percentage was high, varied and multiple. We suggest systematic revision of references in the editorial process as well as to extend the discussion on this theme. references, periodicals, research, bibliometrics.

  2. Windows of Opportunity for Lifestyle Interventions to Prevent Gestational Diabetes Mellitus

    PubMed Central

    Phelan, Suzanne

    2017-01-01

    Gestational diabetes mellitus (GDM) is linked with several acute maternal health risks and long-term development of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM similarly increases offspring risk of early life health complications and later disease. GDM recurrence is common, affecting 40–73% of women, and augments associated maternal/fetal/child health risks. Modifiable and independent risk factors for GDM include maternal excessive gestational weight gain and pre-pregnancy overweight and obesity. Lifestyle interventions that target diet, activity, and behavioral strategies can effectively modify adiposity. Randomized clinical trials testing the effects of lifestyle interventions during pregnancy to reduce excessive gestational weight gain have generally shown mixed effects on reducing GDM incidence. Trials testing the effects of postpartum lifestyle interventions among women with a history of GDM have shown reduced incidence of diabetes and improved cardiovascular disease risk factors. However, the long-term effects of inter-pregnancy or pre-pregnancy lifestyle interventions on subsequent GDM remain unknown. Future adequately powered and well-controlled clinical trials are needed to determine the effects of lifestyle interventions to prevent GDM and identify pathways to effectively reach reproductive-aged women across all levels of society, before, during, and after pregnancy. PMID:27487229

  3. Microbiota and prebiotics modulation of uremic toxin generation.

    PubMed

    Koppe, Laetitia; Fouque, Denis

    2017-06-01

    Recent data have shown that the host-intestinal microbiota interaction is intrinsically linked with overall health. Chronic kidney disease (CKD) could influence intestinal microbiota and gut dysbiosis is also considered as a cause of progression of kidney disease. An increasing body of evidence indicates that dysbiosis is a key contributor of uremic retention solutes (URS) accumulating in patients with CKD. The discovery of the kidney-gut axis has created new therapeutic opportunities for nutritional intervention in order to prevent adverse outcomes. One of these strategies is prebiotics, which refers to nondigestible food ingredients or substances that beneficial affect growth and/or activity of limited health-promoting bacteria in the gastrointestinal tract. The influence of prebiotics on the production and concentration of URS have been investigated in various animal and human CKD studies. However, to date, there is still paucity of high-quality intervention trials. Randomized controlled trials and adequately powered intervention studies are needed before recommending prebiotics in clinical practice. This review will outline the interconnection between CKD progression, dysbiosis and URS production and will discuss mechanisms of action and efficacy of prebiotics as a new CKD management tool, with a particular emphasis on URS generation.

  4. Dialysis modality and survival: Done to death.

    PubMed

    Trinh, Emilie; Chan, Christopher T; Perl, Jeffrey

    2018-03-14

    The debate surrounding whether peritoneal dialysis or hemodialysis is associated with differential survival continues as the numerous comparative studies over the past 3 decades have yielded conflicting results. Findings have also evolved over time in the setting of changing patient characteristics, advances in dialytic technologies, and the use of more robust statistical and epidemiologic approaches. Here, we will critically review the body of evidence, both historical and contemporary, comparing survival across dialysis modalities. Significant limitations of the observational nature of the current literature will be highlighted given that no adequately powered randomized controlled trials exist. Given the lack of consistency and limitations of current studies, coupled with the poor survival across both modalities, we can likely conclude that survival comparisons between both modalities do not appreciably differ. Hence, the choice of dialysis modality should not be dictated by survival comparisons, but rather be based on an individualized and informed decision making that places patient preference and lifestyle considerations at the forefront, while integrating medical factors and availability of resources and support. The emphasis of future research should move beyond survival outcomes when comparing dialysis modalities, and instead be redirected to patient-endorsed and patient-reported outcomes. © 2018 Wiley Periodicals, Inc.

  5. [Research progress of dipeptidyl peptidase 4 inhibitors on healing of chronic diabetic foot ulcers].

    PubMed

    Gao, Yunyi; Liang, Yujie; Ran, Xingwu

    2018-05-01

    To review the effect of dipeptidyl peptidase 4 (DPP-4) inhibitors on the wound healing and its mechanisms in chronic diabetic foot ulcers. The latest literature concerning DPP-4 inhibitors for chronic diabetic foot ulcers was extensively reviewed, as well as the potential benefit and mechanism of DPP-4 inhibitors on wound healing of diabetic foot ulcers was analyzed thoroughly. DPP-4 inhibitors can accelerated the ulcer healing. The mechanisms probably include inhibiting the expression of the matrix metalloproteinase (MMP) and restoring the balance of the wound MMP and the tissue inhibitors of MMP; promoting recruitment of endothelial progenitor cells and augmenting angiogenesis; optimizing extracellular matrix construction and the immune response to persistent hypoxia in chronic diabetes wounds, and so on. At present, clinical researches show that DPP-4 inhibitors may be considered as an adjuvant treatment for chronic diabetic foot ulcers. DPP-4 inhibitors show promise in the local wound healing of chronic diabetic foot ulcers. However, more strictly designed, adequately powered, long-term follow-up, and high-quality randomized control trials are needed to further verify their efficacy and safety for chronic diabetic foot ulcers.

  6. A repeated measures model for analysis of continuous outcomes in sequential parallel comparison design studies.

    PubMed

    Doros, Gheorghe; Pencina, Michael; Rybin, Denis; Meisner, Allison; Fava, Maurizio

    2013-07-20

    Previous authors have proposed the sequential parallel comparison design (SPCD) to address the issue of high placebo response rate in clinical trials. The original use of SPCD focused on binary outcomes, but recent use has since been extended to continuous outcomes that arise more naturally in many fields, including psychiatry. Analytic methods proposed to date for analysis of SPCD trial continuous data included methods based on seemingly unrelated regression and ordinary least squares. Here, we propose a repeated measures linear model that uses all outcome data collected in the trial and accounts for data that are missing at random. An appropriate contrast formulated after the model has been fit can be used to test the primary hypothesis of no difference in treatment effects between study arms. Our extensive simulations show that when compared with the other methods, our approach preserves the type I error even for small sample sizes and offers adequate power and the smallest mean squared error under a wide variety of assumptions. We recommend consideration of our approach for analysis of data coming from SPCD trials. Copyright © 2013 John Wiley & Sons, Ltd.

  7. The analysis of parameters of the cryogenic oxygen unit cooperating with power plant to realize oxy-fuel combustion

    NASA Astrophysics Data System (ADS)

    Hnydiuk-Stefan, Anna; Składzień, Jan

    2015-03-01

    The paper examines from the thermodynamic point of view operation of coal fired power unit cooperating with the cryogenic oxygen unit, with a particular emphasis on the characteristic performance parameters of the oxygen unit. The relatively high purity technical oxygen produced in the oxygen unit is then used as the oxidant in the fluidized bed boiler of the modern coal fired power unit with electric power output of approximately 460 MW. The analyzed oxygen unit has a classical two-column structure with an expansion turbine (turboexpander), which allows the use of relatively low pressure initially compressed air. Multivariant calculations were performed, the main result being the loss of power and efficiency of the unit due to the need to ensure adequate driving power to the compressor system of the oxygen generating plant.

  8. Extending the applied software in the contemporary thermal power plants for increasing the intelligence of the automatic control system

    NASA Astrophysics Data System (ADS)

    Krokhin, G.; Pestunov, A.; Arakelyan, E.; Mukhin, V.

    2017-11-01

    During the last decades, there can be noticed an increase of interest concerning various aspects of intellectual diagnostics and management in thermal power engineering according the hybrid principle. It is conditioned by the fact that conservative static methods does not allow to reflect the actual power installation state adequately. In order to improve the diagnostics quality, we use various fuzzy systems apparatus. In this paper, we introduce the intellectual system, called SKAIS, which is intended for quick and precise diagnostics of thermal power equipment. This system was developed as the result of the research carried out by specialists from National Research University “Moscow Power Engineering Institute” and Novosibirsk State University of Economics and Management. It drastically increases the level of intelligence of the automatic power plant control system.

  9. A preliminary randomised controlled study of short-term Antrodia cinnamomea treatment combined with chemotherapy for patients with advanced cancer.

    PubMed

    Tsai, Ming-Yen; Hung, Yu-Chiang; Chen, Yen-Hao; Chen, Yung-Hsiang; Huang, Yu-Chuen; Kao, Chao-Wei; Su, Yu-Li; Chiu, Hsien-Hsueh Elley; Rau, Kun-Ming

    2016-08-26

    Antrodia cinnamomea (AC) is a popular medicinal mushroom in Taiwan that has been widely used for treatment of various cancers. Few clinical studies have reported its application and efficiency in therapeutic chemotherapy strategies. We performed a double-blind, randomized clinical study to investigate whether AC given for 30 days had acceptable safety and efficacy in advanced cancer patients receiving chemotherapy. Patients with advanced and/or metastatic adenocarcinoma, performance status (PS) 0-2, and adequate organ function who had previously been treated with standard chemotherapy were randomly assigned to receive routine chemotherapy regimens with AC (20 ml twice daily) orally for 30 days or placebo. The primary endpoint was 6-month overall survival (OS); the secondary endpoints were disease control rate (DCR), quality of life (QoL), adverse event (AE), and biochemical features within 30 days of treatment. From August 2010 to July 2012, 37 subjects with gastric, lung, liver, breast, and colorectal cancer (17 in the AC group, 20 in the placebo group) were enrolled in the study. Disease progression was the primary cause of death in 4 (33.3 %) AC and 8 (66.7 %) placebo recipients. Mean OSs were 5.4 months for the AC group and 5.0 months for the placebo group (p = 0.340), and the DCRs were 41.2 and 55 %, respectively (p = 0.33). Most hematologic, liver, or kidney functions did not differ significantly between the two groups, but platelet counts were lower in the AC group than in the placebo group (p = 0.02). QoL assessments were similar in the two groups, except that the AC group showed significant improvements in quality of sleep (p = 0.04). Although we found a lower mortality rate and longer mean OS in the AC group than in the control group, A. cinnamomea combined with chemotherapy was not shown to improve the outcome of advanced cancer patients, possibly due to the small sample size. In fact, the combination may present a potential risk of lowered platelet counts. Adequately powered clinical trials will be necessary to address this question. ClinicalTrials.gov NCT01287286 .

  10. Are NCLB's Measures, Incentives, and Improvement Strategies the Right Ones for the Nation's Low-Performing High Schools?

    ERIC Educational Resources Information Center

    Balfanz, Robert; Legters, Nettie; West, Thomas C.; Weber, Lisa M.

    2007-01-01

    This article examines the extent to which adequate yearly progress (AYP) is a valid and reliable indicator of improvement in low-performing high schools. For a random subsample of 202 high schools, the authors investigate the school characteristics and the federal and state policy contexts that influence their AYP status. Logistic regression…

  11. Suicide Attempts and Nonsuicidal Self-Injury in the Treatment of Resistant Depression in Adolescents: Findings from the TORDIA Study

    ERIC Educational Resources Information Center

    Asarnow, Joan Rosenbaum; Porta, Giovanna; Spirito, Anthony; Emslie, Graham; Clarke, Greg; Wagner, Karen Dineen; Vitiello, Benedetto; Keller, Martin; Birmaher, Boris; McCracken, James; Mayes, Taryn; Berk, Michelle; Brent, David A.

    2011-01-01

    Objective: To evaluate the clinical and prognostic significance of suicide attempts (SAs) and nonsuicidal self-injury (NSSI) in adolescents with treatment-resistant depression. Method: Depressed adolescents who did not improve with an adequate SSRI trial (N = 334) were randomized to a medication switch (SSRI or venlafaxine), with or without…

  12. Course Shopping in Urban Community Colleges: An Analysis of Student Drop and Add Activities

    ERIC Educational Resources Information Center

    Hagedorn, Linda Serra; Maxwell, William E.; Cypers, Scott; Moon, Hye Sun; Lester, Jaime

    2007-01-01

    This study examined the course shopping behaviors among a sample of approximately 5,000 community college students enrolled across nine campuses of a large urban district. The sample was purposely designed as an analytic, rather than a random, sample that sought to obtain adequate numbers of students in course areas that were of theoretical and of…

  13. Evaluating Motivational Enhancement Therapy Adherence and Competence Among Spanish-speaking Therapists

    PubMed Central

    Santa Ana, Elizabeth J.; Carroll, Kathleen M.; Añez, Luis; Paris, Manuel; Ball, Samuel A.; Nich, Charla; Frankforter, Tami L.; Suarez-Morales, Lourdes; Szapocznik, José; Martino, Steve

    2009-01-01

    Despite the fact that the number of Hispanic individuals in need of treatment for substance use problems is increasing internationally, no studies have investigated the extent to which therapists can provide empirically supported treatments to Spanish-speaking clients with adequate fidelity. Twenty-three bilingual Hispanic therapists from five community outpatient treatment programs in the United States were randomly assigned to deliver either three sessions of motivational enhancement therapy (MET) or an equivalent number of drug counseling-as-usual sessions (CAU) in Spanish to 405 Spanish-speaking clients randomly assigned to these conditions. Independent ratings of 325 sessions indicated the adherence/competence rating system had good to excellent interrater reliability and indicated strong support for an a priori defined fundamental MET skill factor. Support for an advanced MET skill factor was relatively weaker. The rating scale indicated significant differences in therapists’ MET adherence and competence across conditions. These findings indicate that the rating system has promise for assessing the performance of therapists who deliver MET in Spanish and suggest that bilingual Spanish-speaking therapists from the community can be trained to implement MET with adequate fidelity and skill using an intensive multisite training and supervision model. PMID:19394164

  14. Sleep Disordered Breathing in Patients with Heart Failure: Pathophysiology and Management

    PubMed Central

    Sharma, Bhavneesh; McSharry, David; Malhotra, Atul

    2013-01-01

    Opinion statement Sleep disordered breathing (SDB) is common in heart failure patients across the range of ejection fractions and is associated with adverse prognosis. Although effective pharmacologic and device-based treatment of heart failure may reduce the frequency or severity of SDB, heart failure treatment alone may not be adequate to restore normal breathing during sleep. Continuous positive airway pressure (CPAP) is the major treatment for SDB in heart failure, especially if obstructive rather than central sleep apnea (CSA) predominates. Adequate suppression of CSA by PAP is associated with a heart transplant-free survival benefit, although randomized trials are ongoing. Bilevel PAP (BPAP) may be as effective as CPAP in treating SDB and may be preferable over CPAP in patients who experience expiratory pressure discomfort. Adaptive (or auto) servo-ventilation (ASV), which adjusts the PAP depending on the patient’s airflow or tidal volume, may be useful in congestive heart failure patients if CPAP is ineffective. Other therapies that have been proposed for SDB in congestive heart failure include nocturnal oxygen, CO2 administration (by adding dead space), theophylline, and acetazolamide; most of which have not been systematically studied in outcome-based prospective randomized trials. PMID:21894522

  15. A community-based randomized controlled trial of Mom Power parenting intervention for mothers with interpersonal trauma histories and their young children.

    PubMed

    Rosenblum, Katherine L; Muzik, Maria; Morelen, Diana M; Alfafara, Emily A; Miller, Nicole M; Waddell, Rachel M; Schuster, Melisa M; Ribaudo, Julie

    2017-10-01

    We conducted a study to evaluate the effectiveness of Mom Power, a multifamily parenting intervention to improve mental health and parenting among high-risk mothers with young children in a community-based randomized controlled trial (CB-RCT) design. Participants (N = 122) were high-risk mothers (e.g., interpersonal trauma histories, mental health problems, poverty) and their young children (age <6 years), randomized either to Mom Power, a parenting intervention (treatment condition), or weekly mailings of parenting information (control condition). In this study, the 13-session intervention was delivered by community clinicians trained to fidelity. Pre- and post-trial assessments included mothers' mental health symptoms, parenting stress and helplessness, and connection to care. Mom Power was delivered in the community with fidelity and had good uptake (>65%) despite the risk nature of the sample. Overall, we found improvements in mental health and parenting stress for Mom Power participants but not for controls; in contrast, control mothers increased in parent-child role reversal across the trial period. The benefits of Mom Power treatment (vs. control) were accentuated for mothers with interpersonal trauma histories. Results of this CB-RCT confirm the effectiveness of Mom Power for improving mental health and parenting outcomes for high-risk, trauma-exposed women with young children. ClinicalTrials.gov Identifier: NCT01554215.

  16. Safe delivery of optical power from space.

    PubMed

    Smith, M; Fork, R L; Cole, S

    2001-05-07

    More than a billion gigawatts of sunlight pass through the area extending from Earth out to geostationary orbit. A small fraction of this clean renewable power appears more than adequate to satisfy the projected needs of Earth, and of human exploration and development of space far into the future. Recent studies suggest safe and efficient access to this power can be achieved within 10 to 40 years. Light, enhanced in spatial and temporal coherence, as compared to natural sunlight, offers a means, and probably the only practical means, of usefully transmitting this power to Earth. We describe safety standards for satellite constellations and Earth based sites designed, respectively, to transmit, and receive this power. The spectral properties, number of satellites, and angle subtended at Earth that are required for safe delivery are identified and discussed.

  17. Improved control strategy for wind-powered refrigerated storage of apples

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baldwin, J.D.C.

    1979-01-01

    The need for an improved control strategy for the operation of a wind-powered refrigeration system for the storage of apples was investigated. The results are applicable to other systems which employ intermittently available power sources, battery and thermal storage, and an auxiliary, direct current power supply. Tests were conducted on the wind-powered refrigeration system at the Virginia Polytechnic Institute and State University Horticulture Research Farm in Blacksburg, Virginia. Tests were conducted on the individual components of the system. In situ windmill performance was also conducted. The results of these tests have been presented. An improved control strategy was developed tomore » improve the utilization of available wind energy and to reduce the need for electrical energy from an external source while maintaining an adequate apple storage environment.« less

  18. Mechanochemical endovenous ablation versus radiofrequency ablation in the treatment of primary small saphenous vein insufficiency (MESSI trial): study protocol for a randomized controlled trial.

    PubMed

    Boersma, Doeke; van Eekeren, Ramon R J P; Kelder, Hans J C; Werson, Debora A B; Holewijn, Suzanne; Schreve, Michiel A; Reijnen, Michel M P J; de Vries, Jean Paul P M

    2014-10-29

    Minimally invasive endothermal techniques, for example, radiofrequency ablation (RFA), have revolutionized the treatment of insufficient truncal veins and are associated with an excellent outcome. The use of thermal energy requires the instillation of tumescent anesthesia around the vein. Mechanochemical endovenous ablation (MOCA™) combines mechanical endothelial damage, using a rotating wire, with simultaneous infusion of a liquid sclerosans. Tumescent anesthesia is not required as no heat is used. Prospective studies using MOCA™ in both great and small saphenous veins showed good anatomical and clinical results with fast postoperative recovery. The MESSI trial (Mechanochemical Endovenous ablation versus radiofrequency ablation in the treatment of primary Small Saphenous vein Insufficiency) is a multicenter randomized controlled trial in which a total of 160 patients will be randomized (1:1) to MOCA™ or RFA. Consecutive patients with primary small saphenous vein incompetence, who meet the eligibility criteria, will be invited to participate in this trial. The primary endpoint is anatomic success, defined as occlusion of the treated veins objectified with duplex ultrasonography at 1 year follow-up. Secondary endpoints are post-procedural pain, initial technical success, clinical success, complications and the duration of the procedure. Initial technical success is defined as the ability to position the device adequately, treat the veins as planned and occlude the treated vein directly after the procedure has been proven by duplex ultrasonography. Clinical success is defined as an objective improvement of clinical outcome after treatment, measured with the Venous Clinical Severity Score (VCSS). Power analyses are conducted for anatomical success and post-procedural pain.Both groups will be evaluated on an intention-to-treat principle. The hypothesis of the MESSI trial is that the anatomic success rate of MOCA™ is not inferior to RFA. The second hypothesis is that post-procedural pain is significantly less after MOCA compared to RFA. NTR4613 Date of trial registration: 28 May 2014.

  19. Active video games as a tool to prevent excessive weight gain in adolescents: rationale, design and methods of a randomized controlled trial.

    PubMed

    Simons, Monique; Chinapaw, Mai J M; van de Bovenkamp, Maaike; de Boer, Michiel R; Seidell, Jacob C; Brug, Johannes; de Vet, Emely

    2014-03-24

    Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games--i.e. active games--may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12-16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents' measured BMI-SDS (SDS=adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents' self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents. Dutch Trial register NTR3228.

  20. Expert patient self-management program versus usual care in bronchiectasis: a randomized controlled trial.

    PubMed

    Lavery, Katherine A; O'Neill, Brenda; Parker, Michael; Elborn, J Stuart; Bradley, Judy M

    2011-08-01

    To investigate the efficacy of a disease-specific Expert Patient Programme (EPP) compared with usual care in patients with bronchiectasis. Proof-of-concept randomized controlled trial. Regional respiratory center. Adult patients (N=64; age, >18y) with a primary diagnosis of bronchiectasis based on a respiratory physician's assessment including a computed tomographic scan. Patients were randomly assigned to an intervention (usual care plus EPP; n=32) or control group (usual care only; n=32). The primary outcome measure was the Chronic Disease Self-efficacy Scale (CDSS). Other outcome measures included the Revised Illness Perception Questionnaire (IPQ-R), the St Georges Respiratory Questionnaire, and standard EPP questionnaires. Data were collected at baseline, postintervention, and 3 and 6 months postintervention. This disease-specific EPP for patients with bronchiectasis significantly improved self-efficacy in 6 of 10 subscales (CDSS subscales: exercise regularly [P=.02]; get information about disease [P=.03]; obtain help from community, family, and friends [P=.06]; communicate with physician [P=.85]; manage disease in general [P=.05]; do chores [P=.04]; social/recreational activities [P=.03]; manage symptoms [P<.01]; manage shortness of breath [P=.08]; control/manage depression [P=.01]) compared with usual care. There was no improvement on IPQ-R score. Patients who received the intervention reported more symptoms and decreased quality of life between 3 and 6 months postintervention and an increase in some components of self reported health care use. Patients receiving the disease-specific EPP indicated they were satisfied with the intervention and learned new self-management techniques. There were no significant differences in lung function over time. This original study indicates that a disease-specific EPP results in short-term improvements in self-efficacy. Based on these positive preliminary findings, a larger adequately powered study is justified to investigate the efficacy of a disease-specific EPP in patients with bronchiectasis. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  1. Effects of Statin Treatment on Inflammation and Cardiac Function in Heart Failure: An Adjusted Indirect Comparison Meta-Analysis of Randomized Trials.

    PubMed

    Bonsu, Kwadwo Osei; Reidpath, Daniel Diamond; Kadirvelu, Amudha

    2015-12-01

    Statins are known to prevent heart failure (HF). However, it is unclear whether statins as class or type (lipophilic or hydrophilic) improve outcomes of established HF. The current meta-analysis was performed to compare the treatment effects of lipophilic and hydrophilic statins on inflammation and cardiac function in HF. Outcomes were indicators of cardiac function [changes in left ventricular ejection fraction (LVEF) and B-type natriuretic peptide (BNP)] and inflammation [changes in highly sensitive C-reactive protein (hsCRP) and interluekin-6 (IL-6)]. We conducted a search of PubMed, EMBASE, and the Cochrane databases until December 31, 2014 for randomized control trials (RCTs) of statin versus placebo in patients with HF. RCTs with their respective extracted information were dichotomized into statin type evaluated and analyzed separately. Outcomes were pooled with random effect approach, producing standardized mean differences (SMD) for each statin type. Using these pooled estimates, we performed adjusted indirect comparisons for each outcome. Data from 6214 patients from 19 trials were analyzed. Lipophilic statin was superior to hydrophilic statin treatment regarding follow-up LVEF (SMD, 4.54; 95% CI, 4.16-4.91; P < 0.001), BNP (SMD, -1.60; 95% CI, -2.56 to -0.65; P < 0.001), hsCRP (SMD, -1.13; 95% CI, -1.54 to -0.72; P < 0.001), and IL-6 (SMD, -3.75; 95% CI, -4.77 to -0.72; P < 0.001) in HF. Lipophilic statin produces greater treatment effects on cardiac function and inflammation compared with hydrophilic statin in patients with HF. Until data from adequately powered head-to-head trial of the statin types are available, our meta-analysis brings clinicians and researchers a step closer to the quest on which statin--lipophilic or hydrophilic--is associated with better outcomes in HF. © 2015 John Wiley & Sons Ltd.

  2. Active video games as a tool to prevent excessive weight gain in adolescents: rationale, design and methods of a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Excessive body weight, low physical activity and excessive sedentary time in youth are major public health concerns. A new generation of video games, the ones that require physical activity to play the games –i.e. active games- may be a promising alternative to traditional non-active games to promote physical activity and reduce sedentary behaviors in youth. The aim of this manuscript is to describe the design of a study evaluating the effects of a family oriented active game intervention, incorporating several motivational elements, on anthropometrics and health behaviors in adolescents. Methods/Design The study is a randomized controlled trial (RCT), with non-active gaming adolescents aged 12 – 16 years old randomly allocated to a ten month intervention (receiving active games, as well as an encouragement to play) or a waiting-list control group (receiving active games after the intervention period). Primary outcomes are adolescents’ measured BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds. Secondary outcomes are adolescents’ self-reported time spent playing active and non-active games, other sedentary activities and consumption of sugar-sweetened beverages. In addition, a process evaluation is conducted, assessing the sustainability of the active games, enjoyment, perceived competence, perceived barriers for active game play, game context, injuries from active game play, activity replacement and intention to continue playing the active games. Discussion This is the first adequately powered RCT including normal weight adolescents, evaluating a reasonably long period of provision of and exposure to active games. Next, strong elements are the incorporating motivational elements for active game play and a comprehensive process evaluation. This trial will provide evidence regarding the potential contribution of active games in prevention of excessive weight gain in adolescents. Trial registration Dutch Trial register NTR3228. PMID:24661535

  3. Joining the Dots: The Challenge of Creating Coherent School Improvement

    ERIC Educational Resources Information Center

    Robinson, Viviane; Bendikson, Linda; McNaughton, Stuart; Wilson, Aaron; Zhu, Tong

    2017-01-01

    Background/Context: Sustained school improvement requires adequate organizational and instructional coherence, yet, in typical high schools, subject department organization, norms of teacher professional autonomy, and involvement in multiple initiatives present powerful obstacles to forging a coherent approach to improvement. This study examines…

  4. 46 CFR 183.360 - Semiconductor rectifier systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Semiconductor rectifier systems. 183.360 Section 183.360... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents...

  5. Thermal Pollution Impact upon Aquatic Life.

    ERIC Educational Resources Information Center

    Shiomoto, Gail T.; Olson, Betty H.

    1978-01-01

    Conventional and nuclear power plants release waste heat to cooling water which then returns to receiving bodies of surface water. This thermal pollution causes a variety of effects in the aquatic ecosystem. More must be learned about these effects to ensure adequate regulation of thermal discharges. (RE)

  6. Advances in electrometer vacuum tube design

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Single-ended, miniature-cathode tube with a relatively low grid current level is constructed. Adequate cathode temperature at relatively low heater power drain is provided by designing the supporting spacers to provide a square cathode hole. Method of assembling the mount and bonding the elements is discussed.

  7. 46 CFR 183.360 - Semiconductor rectifier systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Semiconductor rectifier systems. 183.360 Section 183.360... TONS) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents...

  8. Statistical power and optimal design in experiments in which samples of participants respond to samples of stimuli.

    PubMed

    Westfall, Jacob; Kenny, David A; Judd, Charles M

    2014-10-01

    Researchers designing experiments in which a sample of participants responds to a sample of stimuli are faced with difficult questions about optimal study design. The conventional procedures of statistical power analysis fail to provide appropriate answers to these questions because they are based on statistical models in which stimuli are not assumed to be a source of random variation in the data, models that are inappropriate for experiments involving crossed random factors of participants and stimuli. In this article, we present new methods of power analysis for designs with crossed random factors, and we give detailed, practical guidance to psychology researchers planning experiments in which a sample of participants responds to a sample of stimuli. We extensively examine 5 commonly used experimental designs, describe how to estimate statistical power in each, and provide power analysis results based on a reasonable set of default parameter values. We then develop general conclusions and formulate rules of thumb concerning the optimal design of experiments in which a sample of participants responds to a sample of stimuli. We show that in crossed designs, statistical power typically does not approach unity as the number of participants goes to infinity but instead approaches a maximum attainable power value that is possibly small, depending on the stimulus sample. We also consider the statistical merits of designs involving multiple stimulus blocks. Finally, we provide a simple and flexible Web-based power application to aid researchers in planning studies with samples of stimuli.

  9. Perceptions on the right to adequate food after a major landslide disaster: a cross-sectional survey of two districts in Uganda.

    PubMed

    Rukundo, Peter M; Iversen, Per O; Andreassen, Bård A; Oshaug, Arne; Kikafunda, Joyce; Rukooko, Byaruhanga

    2015-04-25

    Despite the instruments on the right to adequate food adopted by the United Nations, there exists limited information on how this right is perceived. Following a major 2010 landslide disaster in the Bududa district of Eastern Uganda and the resettlement of some affected households into the Kiryandongo district in Western Uganda, we surveyed both districts to explore perceptions about the right to adequate food among households with different experiences; disaster-affected and controls. We deployed qualitative and quantitative techniques to a cross-sectional survey. The index respondent was the head of each randomly selected household from the landslide affected communities and controls from a bordering sub-county. Data was collected by interviews and focus group discussions (FGDs). Structured entries were tested statistically to report associations using Pearson's Chi-square at the 95% CI. Information from FGDs was transcribed, coded, sequenced and patterned. Findings from both techniques were triangulated to facilitate interpretations. Analysis included 1,078 interview entries and 12 FGDs. Significant differences between the affected and control households (P < 0.05) were observed with: age; education level; religious affiliation; existence of assets that complement food source; and having received relief food. Analysis between groups showed differences in responses on: whether everyone has a right to adequate food; who was supposed to supply relief food; whether relief food was adequate; and preferred choice on the means to ensure the right to adequate food. FGDs emphasized that access to land was the most important means to food and income. Affected households desired remedial interventions especially alternative land for livelihood. Despite the provision of adequate relief food being a state's obligation, there was no opportunity to exercise choice and preference. Comprehension and awareness of accountability and transparency issues was also low. Though a significant proportion of participants affirmed they have a right to adequate food, relief food was largely perceived as insufficient. Given the high regard for land as a preferred remedy, a resettlement policy is of the essence to streamline post-landslide displacement and resettlement. Information materials need to be assembled and disseminated to stimulate awareness and debate on the right to adequate food.

  10. Acta Aeronautica et Astronautica Sinica,

    DTIC Science & Technology

    1983-03-04

    power spectrum and counting methods [1,2,3]. If the stochastic load-time mechanism (such as gusts of wind, random 38...34 "- " ° - " . . .. . . . . . . . . ’ - - - Ř vibrations, etc.), then we can use the power spectrum technique, and we can also use the counting method. However, the...simplification for treat - ment so that the differences in obtained results are very minute, and are also closest to the random spectrum. This then tells us

  11. Isolated Power Generation System Using Permanent Magnet Synchronous Generator with Improved Power Quality

    NASA Astrophysics Data System (ADS)

    Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh

    2018-06-01

    This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.

  12. Isolated Power Generation System Using Permanent Magnet Synchronous Generator with Improved Power Quality

    NASA Astrophysics Data System (ADS)

    Arya, Sabha Raj; Patel, Ashish; Giri, Ashutosh

    2018-03-01

    This paper deals wind energy based power generation system using Permanent Magnet Synchronous Generator (PMSG). It is controlled using advanced enhanced phase-lock loop for power quality features using distribution static compensator to eliminate the harmonics and to provide KVAR compensation as well as load balancing. It also manages rated potential at the point of common interface under linear and non-linear loads. In order to have better efficiency and reliable operation of PMSG driven by wind turbine, it is necessary to analyze the governing equation of wind based turbine and PMSG under fixed and variable wind speed. For handling power quality problems, power electronics based shunt connected custom power device is used in three wire system. The simulations in MATLAB/Simulink environment have been carried out in order to demonstrate this model and control approach used for the power quality enhancement. The performance results show the adequate performance of PMSG based power generation system and control algorithm.

  13. Fourier Transformation Theory for Averaged Functions, with Application to Very Long Baseline Radio Interferometry.

    DTIC Science & Technology

    1981-02-01

    primary parameters affecting the SNR. For an earth-based interferometer, the physical aperture may usually be constructed adequately large to keep the...bandwidth Av cent--.c. on vo0 by an interferometer with frequency characteristic F(v) and primary power pattern G(s-s ) (defined as the product of the...infinitely narrow beam for the primary power pattern, G(g- 0 ) = (;-S )] we have where we have assumed a flat frequency response and included as a

  14. Risk management and regulations for lower limb medical exoskeletons: a review

    PubMed Central

    He, Yongtian; Eguren, David; Luu, Trieu Phat; Contreras-Vidal, Jose L

    2017-01-01

    Gait disability is a major health care problem worldwide. Powered exoskeletons have recently emerged as devices that can enable users with gait disabilities to ambulate in an upright posture, and potentially bring other clinical benefits. In 2014, the US Food and Drug Administration approved marketing of the ReWalk™ Personal Exoskeleton as a class II medical device with special controls. Since then, Indego™ and Ekso™ have also received regulatory approval. With similar trends worldwide, this industry is likely to grow rapidly. On the other hand, the regulatory science of powered exoskeletons is still developing. The type and extent of probable risks of these devices are yet to be understood, and industry standards are yet to be developed. To address this gap, Manufacturer and User Facility Device Experience, Clinicaltrials.gov, and PubMed databases were searched for reports of adverse events and inclusion and exclusion criteria involving the use of lower limb powered exoskeletons. Current inclusion and exclusion criteria, which can determine probable risks, were found to be diverse. Reported adverse events and identified risks of current devices are also wide-ranging. In light of these findings, current regulations, standards, and regulatory procedures for medical device applications in the USA, Europe, and Japan were also compared. There is a need to raise awareness of probable risks associated with the use of powered exoskeletons and to develop adequate countermeasures, standards, and regulations for these human-machine systems. With appropriate risk mitigation strategies, adequate standards, comprehensive reporting of adverse events, and regulatory oversight, powered exoskeletons may one day allow individuals with gait disabilities to safely and independently ambulate. PMID:28533700

  15. Preliminary design of a space system operating a ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    D'Errico, Marco; Ponte, Salvatore; Grassi, Michele; Moccia, Antonio

    2005-12-01

    Ground-penetrating radars (GPR) are currently used only in ground campaigns or in few airborne installations. A feasibility analysis of a space mission operating a GPR for archaeological applications is presented in this work with emphasis on spacecraft critical aspects: antenna dimension and power required for achieving adequate depth and accuracy. Sensor parametric design is performed considering two operating altitudes (250 and 500 km) and user requirements, such as minimum skin depth, vertical and horizontal resolution. A 500-km altitude, 6 a.m.-6 p.m. sun-synchronous orbit is an adequate compromise between atmospheric drag and payload transmitted average power (12 kW) to achieve a 3-m penetration depth. The satellite bus preliminary design is then performed, with focus on critical subsystems and technologies. The payload average power requirement can be kept within feasible limits (1 kW) by using NiH2 batteries to supply the radar transmitter, and with a strong reduction of the mission duty cycle ( 40km×1100km are observed per orbit). As for the electric power subsystem, a dual-voltage strategy is adopted, with the battery charge regulator supplied at 126 V and the bus loads at 50 V. The overall average power (1.9 kW), accounting for both payload and bus needs, can be supplied by a 20m2 GaAs solar panel for a three-year lifetime. Finally, the satellite mass is kept within reasonable limits (1.6 tons) using inflatable-rigidisable structure for both the payload antenna and the solar panels.

  16. Parameters affecting the resilience of scale-free networks to random failures.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Link, Hamilton E.; LaViolette, Randall A.; Lane, Terran

    2005-09-01

    It is commonly believed that scale-free networks are robust to massive numbers of random node deletions. For example, Cohen et al. in (1) study scale-free networks including some which approximate the measured degree distribution of the Internet. Their results suggest that if each node in this network failed independently with probability 0.99, most of the remaining nodes would still be connected in a giant component. In this paper, we show that a large and important subclass of scale-free networks are not robust to massive numbers of random node deletions. In particular, we study scale-free networks which have minimum node degreemore » of 1 and a power-law degree distribution beginning with nodes of degree 1 (power-law networks). We show that, in a power-law network approximating the Internet's reported distribution, when the probability of deletion of each node is 0.5 only about 25% of the surviving nodes in the network remain connected in a giant component, and the giant component does not persist beyond a critical failure rate of 0.9. The new result is partially due to improved analytical accommodation of the large number of degree-0 nodes that result after node deletions. Our results apply to power-law networks with a wide range of power-law exponents, including Internet-like networks. We give both analytical and empirical evidence that such networks are not generally robust to massive random node deletions.« less

  17. Providing Hospitalized Patients With an Educational Booklet Increases the Quality of Colonoscopy Bowel Preparation.

    PubMed

    Ergen, William F; Pasricha, Trisha; Hubbard, Francie J; Higginbotham, Tina; Givens, Tonya; Slaughter, James C; Obstein, Keith L

    2016-06-01

    Inadequate bowel preparation is a problem frequently encountered by gastroenterologists who perform colonoscopies on hospitalized patients. A method is needed to increase the quality of bowel preparation in inpatients. An educational booklet has been shown to increase the overall quality of bowel preparation for outpatients. We performed a prospective study to evaluate the effects of an educational booklet on the quality of bowel preparation in a group of hospitalized patients. We performed a randomized, single-blind, controlled trial of all inpatients at a tertiary care medical center scheduled for inpatient colonoscopy from October 2013 through March 2014. They were randomly assigned to groups that were (n = 45) or were not (controls, n = 40) given the booklet before bowel preparation the evening before their colonoscopy. All patients received a standard bowel preparation (clear liquid diet the day before the procedure, followed by split-dose GoLYTELY). At the colonoscopy, the Boston Bowel preparation scale (BBPS) was used to assess bowel preparation. The primary outcome measure was adequate bowel preparation (a total BBPS score ≥6 with all segment scores ≥2). Secondary outcomes assessed included total BBPS score, BBPS segment score, and a total BBPS score of 0. There were no differences between the groups in age, race, sex, body mass index, history of colonoscopy, history of polyps, or time of colonoscopy. Twenty-eight patients who received the booklet (62%) and 14 who did not (35%) had an adequate bowel preparation (P = .012). The number needed to treat to attain adequate bowel preparation was 4. After adjusting for age and history of prior colonoscopies, the odds of achieving an adequate bowel preparation and a higher total BBPS score after receipt of the booklet were 3.14 (95% confidence interval, 1.29-7.83) and 2.27 (95% confidence interval, 1.05-4.88), respectively. Three patients in the booklet group and 9 in the no-booklet group had a BBPS score of 0 (P = .036). The mean BBPS segment score was greater for the booklet group than the no-booklet group (right colon, P = .097; transverse colon, P = .023; left colon, P = .045). In a randomized controlled trial, we found that providing hospitalized patients with an educational booklet on colonoscopy preparation increases the odds of a quality bowel preparation more than 2-fold. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

  18. Interactive Book Reading to Accelerate Word Learning by Kindergarten Children With Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response.

    PubMed

    Storkel, Holly L; Voelmle, Krista; Fierro, Veronica; Flake, Kelsey; Fleming, Kandace K; Romine, Rebecca Swinburne

    2017-01-01

    This study sought to identify an adequate intensity of interactive book reading for new word learning by children with specific language impairment (SLI) and to examine variability in treatment response. An escalation design adapted from nontoxic drug trials (Hunsberger, Rubinstein, Dancey, & Korn, 2005) was used in this Phase I/II preliminary clinical trial. A total of 27 kindergarten children with SLI were randomized to 1 of 4 intensities of interactive book reading: 12, 24, 36, or 48 exposures. Word learning was monitored through a definition task and a naming task. An intensity response curve was examined to identify the adequate intensity. Correlations and classification accuracy were used to examine variation in response to treatment relative to pretreatment and early treatment measures. Response to treatment improved as intensity increased from 12 to 24 to 36 exposures, and then no further improvements were observed as intensity increased to 48 exposures. There was variability in treatment response: Children with poor phonological awareness, low vocabulary, and/or poor nonword repetition were less likely to respond to treatment. The adequate intensity for this version of interactive book reading was 36 exposures, but further development of the treatment is needed to increase the benefit for children with SLI.

  19. Interactive Book Reading to Accelerate Word Learning by Kindergarten Children With Specific Language Impairment: Identifying an Adequate Intensity and Variation in Treatment Response

    PubMed Central

    Voelmle, Krista; Fierro, Veronica; Flake, Kelsey; Fleming, Kandace K.; Romine, Rebecca Swinburne

    2017-01-01

    Purpose This study sought to identify an adequate intensity of interactive book reading for new word learning by children with specific language impairment (SLI) and to examine variability in treatment response. Method An escalation design adapted from nontoxic drug trials (Hunsberger, Rubinstein, Dancey, & Korn, 2005) was used in this Phase I/II preliminary clinical trial. A total of 27 kindergarten children with SLI were randomized to 1 of 4 intensities of interactive book reading: 12, 24, 36, or 48 exposures. Word learning was monitored through a definition task and a naming task. An intensity response curve was examined to identify the adequate intensity. Correlations and classification accuracy were used to examine variation in response to treatment relative to pretreatment and early treatment measures. Results Response to treatment improved as intensity increased from 12 to 24 to 36 exposures, and then no further improvements were observed as intensity increased to 48 exposures. There was variability in treatment response: Children with poor phonological awareness, low vocabulary, and/or poor nonword repetition were less likely to respond to treatment. Conclusion The adequate intensity for this version of interactive book reading was 36 exposures, but further development of the treatment is needed to increase the benefit for children with SLI. PMID:28036410

  20. Brief Report: A Randomized, Placebo-Controlled Proof-of-Concept Trial of Adjunctive Topiramate for Alcohol Use Disorders in Bipolar Disorder

    PubMed Central

    Sylvia, Louisa G.; Gold, Alexandra K.; Stange, Jonathan P.; Peckham, Andrew D.; Deckersbach, Thilo; Calabrese, Joseph R.; Weiss, Roger D.; Perlis, Roy H.; Nierenberg, Andrew A.; Ostacher, Michael J.

    2016-01-01

    Background and Objectives Topiramate is effective for alcohol use disorders (AUDs) among non-psychiatric patients. We examined topiramate for treating comorbid AUDs in bipolar disorder (BD). Methods Twelve participants were randomized to topiramate or placebo for 12 weeks. Results The topiramate group, with two out of five participants (40%) completing treatment, experienced less improvement in drinking patterns than the placebo group, with five out of seven participants (71%) completing treatment. Discussion and Conclusions Topiramate did not improve drinking behavior and was not well-tolerated. This study failed to recruit adequately. Problems surrounding high attrition, a small study sample, and missing data preclude interpretation of study findings. Scientific Significance This is the first randomized, placebo-controlled trial of topiramate for AUDs in BD. PMID:26894822

  1. Explanation of power law behavior of autoregressive conditional duration processes based on the random multiplicative process

    NASA Astrophysics Data System (ADS)

    Sato, Aki-Hiro

    2004-04-01

    Autoregressive conditional duration (ACD) processes, which have the potential to be applied to power law distributions of complex systems found in natural science, life science, and social science, are analyzed both numerically and theoretically. An ACD(1) process exhibits the singular second order moment, which suggests that its probability density function (PDF) has a power law tail. It is verified that the PDF of the ACD(1) has a power law tail with an arbitrary exponent depending on a model parameter. On the basis of theory of the random multiplicative process a relation between the model parameter and the power law exponent is theoretically derived. It is confirmed that the relation is valid from numerical simulations. An application of the ACD(1) to intervals between two successive transactions in a foreign currency market is shown.

  2. Explanation of power law behavior of autoregressive conditional duration processes based on the random multiplicative process.

    PubMed

    Sato, Aki-Hiro

    2004-04-01

    Autoregressive conditional duration (ACD) processes, which have the potential to be applied to power law distributions of complex systems found in natural science, life science, and social science, are analyzed both numerically and theoretically. An ACD(1) process exhibits the singular second order moment, which suggests that its probability density function (PDF) has a power law tail. It is verified that the PDF of the ACD(1) has a power law tail with an arbitrary exponent depending on a model parameter. On the basis of theory of the random multiplicative process a relation between the model parameter and the power law exponent is theoretically derived. It is confirmed that the relation is valid from numerical simulations. An application of the ACD(1) to intervals between two successive transactions in a foreign currency market is shown.

  3. 46 CFR 111.75-16 - Lighting of survival craft and rescue boats.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Section 111.75-16 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Lighting Circuits and Protection § 111.75-16 Lighting of survival... be adequately illuminated by lighting supplied from the emergency power source. (b) The arrangement...

  4. 29 CFR 1910.254 - Arc welding and cutting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 80 volts. (c) Installation of arc welding equipment—(1) General. Installation including power supply... mechanically strong and electrically adequate for the required current. (3) Supply connections and conductors...-carrying capacity of the supply conductors shall be not less than the rated primary current of the welding...

  5. 46 CFR 129.360 - Semiconductor-rectifier systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Semiconductor-rectifier systems. 129.360 Section 129.360... INSTALLATIONS Power Sources and Distribution Systems § 129.360 Semiconductor-rectifier systems. (a) Each semiconductor-rectifier system must have an adequate heat-removal system to prevent overheating. (b) If a...

  6. 46 CFR 120.360 - Semiconductor rectifier systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Semiconductor rectifier systems. 120.360 Section 120.360... INSTALLATION Power Sources and Distribution Systems § 120.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents overheating. (b) Where a...

  7. 46 CFR 97.80-1 - Special operating conditions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... exhausts of power-operated industrial trucks shall have adequate ventilation. The senior deck officer shall... which persons are working, by persons acquainted with the test equipment and procedure. The carbon monoxide concentration in the holds and intermediate decks where persons are working shall be maintained at...

  8. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste... be adequate to enforce solid waste disposal standards which are equivalent to or more stringent than the criteria for classification of solid waste disposal facilities (40 CFR part 257). Such authority...

  9. 40 CFR 256.21 - Requirements for State regulatory powers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste... be adequate to enforce solid waste disposal standards which are equivalent to or more stringent than the criteria for classification of solid waste disposal facilities (40 CFR part 257). Such authority...

  10. 46 CFR 129.360 - Semiconductor-rectifier systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Semiconductor-rectifier systems. 129.360 Section 129.360... INSTALLATIONS Power Sources and Distribution Systems § 129.360 Semiconductor-rectifier systems. (a) Each semiconductor-rectifier system must have an adequate heat-removal system to prevent overheating. (b) If a...

  11. 46 CFR 120.360 - Semiconductor rectifier systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Semiconductor rectifier systems. 120.360 Section 120.360... INSTALLATION Power Sources and Distribution Systems § 120.360 Semiconductor rectifier systems. (a) Each semiconductor rectifier system must have an adequate heat removal system that prevents overheating. (b) Where a...

  12. Bayesian adaptive trials offer advantages in comparative effectiveness trials: an example in status epilepticus.

    PubMed

    Connor, Jason T; Elm, Jordan J; Broglio, Kristine R

    2013-08-01

    We present a novel Bayesian adaptive comparative effectiveness trial comparing three treatments for status epilepticus that uses adaptive randomization with potential early stopping. The trial will enroll 720 unique patients in emergency departments and uses a Bayesian adaptive design. The trial design is compared to a trial without adaptive randomization and produces an efficient trial in which a higher proportion of patients are likely to be randomized to the most effective treatment arm while generally using fewer total patients and offers higher power than an analogous trial with fixed randomization when identifying a superior treatment. When one treatment is superior to the other two, the trial design provides better patient care, higher power, and a lower expected sample size. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Autocorrelation peaks in congruential pseudorandom number generators

    NASA Technical Reports Server (NTRS)

    Neuman, F.; Merrick, R. B.

    1976-01-01

    The complete correlation structure of several congruential pseudorandom number generators (PRNG) of the same type and small cycle length was studied to deal with the problem of congruential PRNG almost repeating themselves at intervals smaller than their cycle lengths, during simulation of bandpass filtered normal random noise. Maximum period multiplicative and mixed congruential generators were studied, with inferences drawn from examination of several tractable members of a class of random number generators, and moduli from 2 to the 5th power to 2 to the 9th power. High correlation is shown to exist in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle length. The random noise sequences in question are required when simulating electrical noise, air turbulence, or time variation of wind parameters.

  14. Ensuring reliability in expansion schemes.

    PubMed

    Kamal-Uddin, Abu Sayed; Williams, Donald Leigh

    2005-01-01

    Existing electricity power supplies must serve, or be adapted to serve, the expansion of hospital buildings. With the existing power supply assets of many hospitals being up to 20 years old, assessing the security and reliability of the power system must be given appropriate priority to avoid unplanned outages due to overloads and equipment failures. It is imperative that adequate contingency is planned for essential and non-essential electricity circuits. This article describes the methodology undertaken, and the subsequent recommendations that were made, when evaluating the security and reliability of electricity power supplies to a number of major London hospitals. The methodology described aligns with the latest issue of NHS Estates HTM 2011 'Primary Electrical Infrastructure Emergency Electrical Services Design Guidance' (to which ERA Technology has contributed).

  15. Reproducible Growth of High-Quality Cubic-SiC Layers

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Powell, J. Anthony

    2004-01-01

    Semiconductor electronic devices and circuits based on silicon carbide (SiC) are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which devices made from conventional semiconductors cannot adequately perform. The ability of SiC-based devices to function under such extreme conditions is expected to enable significant improvements in a variety of applications and systems. These include greatly improved high-voltage switching for saving energy in public electric power distribution and electric motor drives; more powerful microwave electronic circuits for radar and communications; and sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines.

  16. The ac power line protection for an IEEE 587 Class B environment

    NASA Technical Reports Server (NTRS)

    Roehr, W. D.; Clark, O. M.

    1984-01-01

    The 587B series of protectors are unique, low clamping voltage transient suppressors to protect ac-powered equipment from the 6000V peak open-circuit voltage and 3000A short circuit current as defined in IEEE standard 587 for Category B transients. The devices, which incorporate multiple-stage solid-state protector components, were specifically designed to operate under multiple exposures to maximum threat levels in this severe environment. The output voltage peaks are limited to 350V under maximum threat conditions for a 120V ac power line, thus providing adequate protection to vulnerable electronic equipment. The principle of operation and test performance data is discussed.

  17. Graded junction termination extensions for electronic devices

    NASA Technical Reports Server (NTRS)

    Merrett, J. Neil (Inventor); Isaacs-Smith, Tamara (Inventor); Sheridan, David C. (Inventor); Williams, John R. (Inventor)

    2006-01-01

    A graded junction termination extension in a silicon carbide (SiC) semiconductor device and method of its fabrication using ion implementation techniques is provided for high power devices. The properties of silicon carbide (SiC) make this wide band gap semiconductor a promising material for high power devices. This potential is demonstrated in various devices such as p-n diodes, Schottky diodes, bipolar junction transistors, thyristors, etc. These devices require adequate and affordable termination techniques to reduce leakage current and increase breakdown voltage in order to maximize power handling capabilities. The graded junction termination extension disclosed is effective, self-aligned, and simplifies the implementation process.

  18. Graded junction termination extensions for electronic devices

    NASA Technical Reports Server (NTRS)

    Merrett, J. Neil (Inventor); Isaacs-Smith, Tamara (Inventor); Sheridan, David C. (Inventor); Williams, John R. (Inventor)

    2007-01-01

    A graded junction termination extension in a silicon carbide (SiC) semiconductor device and method of its fabrication using ion implementation techniques is provided for high power devices. The properties of silicon carbide (SiC) make this wide band gap semiconductor a promising material for high power devices. This potential is demonstrated in various devices such as p-n diodes, Schottky diodes, bipolar junction transistors, thyristors, etc. These devices require adequate and affordable termination techniques to reduce leakage current and increase breakdown voltage in order to maximize power handling capabilities. The graded junction termination extension disclosed is effective, self-aligned, and simplifies the implementation process.

  19. Improved control strategy for wind-powered refrigerated storage of apples

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baldwin, J.D.C.; Vaughan, D.H.

    1981-01-01

    A refrigerated apple storage facility was constructed at the VPI and SU Horticultural Research Farm in Blacksburg, Virginia and began operation in March 1978. The system included a 10-kW electric wind generator, electrical battery storage, thermal (ice) storage, and auxiliary power. The need for an improved control system for the VPI and SU system was determined from tests on the individual components and in situ performance tests. The results of these tests formed the basis for an improved control strategy to improve the utilization of available wind energy and reduce the need for auxiliary power while maintaining an adequate applemore » storage environment.« less

  20. Intraperitoneal Vancomycin Plus Either Oral Moxifloxacin or Intraperitoneal Ceftazidime for the Treatment of Peritoneal Dialysis-Related Peritonitis: A Randomized Controlled Pilot Study.

    PubMed

    Xu, Rong; Yang, Zhikai; Qu, Zhen; Wang, Huan; Tian, Xue; Johnson, David W; Dong, Jie

    2017-07-01

    Intraperitoneal administration of antibiotics is recommended as a first treatment for managing peritoneal dialysis (PD)-related peritonitis. However, the efficacy of oral administration of quinolones has not been well studied. Randomized controlled pilot study. 80 eligible patients with PD-related peritonitis from Peking University First Hospital (40 in each arm). Intraperitoneal vancomycin, 1g, every 5 days plus oral moxifloxacin, 400mg, every day (treatment group) versus intraperitoneal vancomycin, 1g, every 5 days plus intraperitoneal ceftazidime, 1g, every day (control group). The primary end point was complete resolution of peritonitis, and secondary end points were primary or secondary treatment failure. PD effluent white blood cell count. Baseline demographic and clinical characteristics of the 2 groups were comparable. There were 24 and 22 Gram-positive organisms, 6 and 7 Gram-negative organisms, 9 and 10 culture-negative samples, and 1 and 1 fungal sample in the treatment and control groups, respectively. Complete resolution of peritonitis was achieved in 78% and 80% of cases in the treatment and control groups, respectively (OR, 0.86; 95% CI, 0.30-2.52; P=0.8). There were 3 and 1 cases of relapse in the treatment and control groups, respectively. Primary and secondary treatment failure rates were not significantly different (33% vs 20% and 10% vs 13%, respectively). In each group, there was 1 peritonitis-related death and 6 transfers to hemodialysis therapy. During the 3-month follow-up period, 7 and 3 successive episodes of peritonitis occurred in the treatment and control groups, respectively. Only 2 adverse drug reactions (mild nausea and mild rash, respectively) were observed in the 2 groups. Sample size was relatively small and the eligibility ratio was low. Also, the number of peritonitis episodes was low, limiting the power to detect a difference between groups. This pilot study suggests that intraperitoneal vancomycin with oral moxifloxacin is a safe, well-tolerated, practical, and effective first-line treatment for PD-related peritonitis. Larger adequately powered clinical trials are warranted. Copyright © 2016 National Kidney Foundation, Inc. All rights reserved.

  1. Factors associated with adequate weekly reporting for disease surveillance data among health facilities in Nairobi County, Kenya, 2013

    PubMed Central

    Mwatondo, Athman Juma; Ng'ang'a, Zipporah; Maina, Caroline; Makayotto, Lyndah; Mwangi, Moses; Njeru, Ian; Arvelo, Wences

    2016-01-01

    Introduction Kenya adopted the Integrated Disease Surveillance and Response (IDSR) strategy in 1998 to strengthen disease surveillance and epidemic response. However, the goal of weekly surveillance reporting among health facilities has not been achieved. We conducted a cross-sectional study to determine the prevalence of adequate reporting and factors associated with IDSR reporting among health facilities in one Kenyan County. Methods Health facilities (public and private) were enrolled using stratified random sampling from 348 facilities prioritized for routine surveillance reporting. Adequately-reporting facilities were defined as those which submitted >10 weekly reports during a twelve-week period and a poor reporting facilities were those which submitted <10 weekly reports. Multivariate logistic regression with backward selection was used to identify risk factors associated with adequate reporting. Results From September 2 through November 30, 2013, we enrolled 175 health facilities; 130(74%) were private and 45(26%) were public. Of the 175 health facilities, 77 (44%) facilities classified as adequate reporting and 98 (56%) were reporting poorly. Multivariate analysis identified three factors to be independently associated with weekly adequate reporting: having weekly reporting forms at visit (AOR19, 95% CI: 6-65], having posters showing IDSR functions (AOR8, 95% CI: 2-12) and having a designated surveillance focal person (AOR7, 95% CI: 2-20). Conclusion The majority of health facilities in Nairobi County were reporting poorly to IDSR and we recommend that the Ministry of Health provide all health facilities in Nairobi County with weekly reporting tools and offer specific trainings on IDSR which will help designate a focal surveillance person. PMID:27303581

  2. Impact of the quality of coronal restoration and root canal filling on the periapical health in adult syrian subpopulation

    PubMed Central

    Alafif, Hisham

    2014-01-01

    Background: The purpose of this study was to determine the status of periapical tissues of endodontically treated teeth according to coronal restorations and root canal fillings separately and in concomitant in adult Syrian subpopulation. Methods: 784 endodontically treated teeth from two hundred randomly selected Syrian adult patients were radiographically evaluated. According to predetermined criteria, the quality of coronal restorations and root canal filling of each tooth was scored as adequate or inadequate. The status of periapical tissues was also classified as healthy or diseased. Results were analyzed using Chi-squared test. Results: Adequate coronal restorations were determined in 58.54% of cases which was accompanied with less periapical pathosis than that in teeth with inadequate restorations (P < 0.01). 14% of teeth were restored by posts which showed no significant impact on the periapical tissues health. 18.5% of endodontic treatments were evaluated as adequate with less number of periapical radiolucencies than that of inadequate root canal fillings (P < 0.01). Absence of periapical pathosis was 96.6% in cases with both adequate coronal restorations and root canals fillings. The rate was 88.5% in cases with only adequate root canals fillings, and about 70% in cases with only adequate coronal restorations. When the treatment was inadequate in both coronal and root canals fillings, success rate was only observed in 48.8%. Conclusion: The most important factor with regard to the periradicular tissue health is the quality of root canal filling without neglecting the influence of coronal restoration (regardless of its type). There is a high prevalence rate of periapical pathosis in Syrian subpopulation due to poor dental practice. PMID:25565729

  3. Multiwavelength generation in a random distributed feedback fiber laser using an all fiber Lyot filter.

    PubMed

    Sugavanam, S; Yan, Z; Kamynin, V; Kurkov, A S; Zhang, L; Churkin, D V

    2014-02-10

    Multiwavelength lasing in the random distributed feedback fiber laser is demonstrated by employing an all fiber Lyot filter. Stable multiwavelength generation is obtained, with each line exhibiting sub-nanometer line-widths. A flat power distribution over multiple lines is obtained, which indicates that the power between lines is redistributed in nonlinear mixing processes. The multiwavelength generation is observed both in first and second Stokes waves.

  4. Radiation Hardened, Modulator ASIC for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

    2000-01-01

    Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

  5. Agricultural and Food Processing Applications of Pulsed Power Technology

    NASA Astrophysics Data System (ADS)

    Takaki, Koichi; Ihara, Satoshi

    Recent progress of agricultural and food processing applications of pulsed power is described in this paper. Repetitively operated compact pulsed power generators with a moderate peak power have been developed for the agricultural and the food processing applications. These applications are mainly based on biological effects and can be categorized as decontamination of air and liquid, germination promotion, inhabitation of saprophytes growth, extraction of juice from fruits and vegetables, and fertilization of liquid medium, etc. Types of pulsed power that have biological effects are caused with gas discharges, water discharges, and electromagnetic fields. The discharges yield free radicals, UV radiation, intense electric field, and shock waves. Biologically based applications of pulsed power are performed by selecting the type that gives the target objects the adequate result from among these agents or byproducts. For instance, intense electric fields form pores on the cell membrane, which is called electroporation, or influence the nuclei.

  6. Programmable random interval generator

    NASA Technical Reports Server (NTRS)

    Lindsey, R. S., Jr.

    1973-01-01

    Random pulse generator can supply constant-amplitude randomly distributed pulses with average rate ranging from a few counts per second to more than one million counts per second. Generator requires no high-voltage power supply or any special thermal cooling apparatus. Device is uniquely versatile and provides wide dynamic range of operation.

  7. Development of the Optimum Operation Scheduling Model of Domestic Electric Appliances for the Supply-Demand Adjustment in a Power System

    NASA Astrophysics Data System (ADS)

    Ikegami, Takashi; Iwafune, Yumiko; Ogimoto, Kazuhiko

    The high penetration of variable renewable generation such as Photovoltaic (PV) systems will cause the issue of supply-demand imbalance in a whole power system. The activation of the residential power usage, storage and generation by sophisticated scheduling and control using the Home Energy Management System (HEMS) will be needed to balance power supply and demand in the near future. In order to evaluate the applicability of the HEMS as a distributed controller for local and system-wide supply-demand balances, we developed an optimum operation scheduling model of domestic electric appliances using the mixed integer linear programming. Applying this model to several houses with dynamic electricity prices reflecting the power balance of the total power system, it was found that the adequate changes in electricity prices bring about the shift of residential power usages to control the amount of the reverse power flow due to excess PV generation.

  8. Real Time Voltage and Current Phase Shift Analyzer for Power Saving Applications

    PubMed Central

    Krejcar, Ondrej; Frischer, Robert

    2012-01-01

    Nowadays, high importance is given to low energy devices (such as refrigerators, deep-freezers, washing machines, pumps, etc.) that are able to produce reactive power in power lines which can be optimized (reduced). Reactive power is the main component which overloads power lines and brings excessive thermal stress to conductors. If the reactive power is optimized, it can significantly lower the electricity consumption (from 10 to 30%—varies between countries). This paper will examine and discuss the development of a measuring device for analyzing reactive power. However, the main problem is the precise real time measurement of the input and output voltage and current. Such quality measurement is needed to allow adequate action intervention (feedback which reduces or fully compensates reactive power). Several other issues, such as the accuracy and measurement speed, must be examined while designing this device. The price and the size of the final product need to remain low as they are the two important parameters of this solution. PMID:23112662

  9. A Simulation Study on the Performance of the Simple Difference and Covariance-Adjusted Scores in Randomized Experimental Designs.

    PubMed

    Petscher, Yaacov; Schatschneider, Christopher

    2011-01-01

    Research by Huck and McLean (1975) demonstrated that the covariance-adjusted score is more powerful than the simple difference score, yet recent reviews indicate researchers are equally likely to use either score type in two-wave randomized experimental designs. A Monte Carlo simulation was conducted to examine the conditions under which the simple difference and covariance-adjusted scores were more or less powerful to detect treatment effects when relaxing certain assumptions made by Huck and McLean (1975). Four factors were manipulated in the design including sample size, normality of the pretest and posttest distributions, the correlation between pretest and posttest, and posttest variance. A 5 × 5 × 4 × 3 mostly crossed design was run with 1,000 replications per condition, resulting in 226,000 unique samples. The gain score was nearly as powerful as the covariance-adjusted score when pretest and posttest variances were equal, and as powerful in fan-spread growth conditions; thus, under certain circumstances the gain score could be used in two-wave randomized experimental designs.

  10. A Simulation Study on the Performance of the Simple Difference and Covariance-Adjusted Scores in Randomized Experimental Designs

    PubMed Central

    Petscher, Yaacov; Schatschneider, Christopher

    2015-01-01

    Research by Huck and McLean (1975) demonstrated that the covariance-adjusted score is more powerful than the simple difference score, yet recent reviews indicate researchers are equally likely to use either score type in two-wave randomized experimental designs. A Monte Carlo simulation was conducted to examine the conditions under which the simple difference and covariance-adjusted scores were more or less powerful to detect treatment effects when relaxing certain assumptions made by Huck and McLean (1975). Four factors were manipulated in the design including sample size, normality of the pretest and posttest distributions, the correlation between pretest and posttest, and posttest variance. A 5 × 5 × 4 × 3 mostly crossed design was run with 1,000 replications per condition, resulting in 226,000 unique samples. The gain score was nearly as powerful as the covariance-adjusted score when pretest and posttest variances were equal, and as powerful in fan-spread growth conditions; thus, under certain circumstances the gain score could be used in two-wave randomized experimental designs. PMID:26379310

  11. Islanding the power grid on the transmission level: less connections for more security

    PubMed Central

    Mureddu, Mario; Caldarelli, Guido; Damiano, Alfonso; Scala, Antonio; Meyer-Ortmanns, Hildegard

    2016-01-01

    Islanding is known as a management procedure of the power system that is implemented at the distribution level to preserve sensible loads from outages and to guarantee the continuity in electricity supply, when a high amount of distributed generation occurs. In this paper we study islanding on the level of the transmission grid and shall show that it is a suitable measure to enhance energy security and grid resilience. We consider the German and Italian transmission grids. We remove links either randomly to mimic random failure events, or according to a topological characteristic, their so-called betweenness centrality, to mimic an intentional attack and test whether the resulting fragments are self-sustainable. We test this option via the tool of optimized DC power flow equations. When transmission lines are removed according to their betweenness centrality, the resulting islands have a higher chance of being dynamically self-sustainable than for a random removal. Less connections may even increase the grid’s stability. These facts should be taken into account in the design of future power grids. PMID:27713509

  12. Islanding the power grid on the transmission level: less connections for more security

    NASA Astrophysics Data System (ADS)

    Mureddu, Mario; Caldarelli, Guido; Damiano, Alfonso; Scala, Antonio; Meyer-Ortmanns, Hildegard

    2016-10-01

    Islanding is known as a management procedure of the power system that is implemented at the distribution level to preserve sensible loads from outages and to guarantee the continuity in electricity supply, when a high amount of distributed generation occurs. In this paper we study islanding on the level of the transmission grid and shall show that it is a suitable measure to enhance energy security and grid resilience. We consider the German and Italian transmission grids. We remove links either randomly to mimic random failure events, or according to a topological characteristic, their so-called betweenness centrality, to mimic an intentional attack and test whether the resulting fragments are self-sustainable. We test this option via the tool of optimized DC power flow equations. When transmission lines are removed according to their betweenness centrality, the resulting islands have a higher chance of being dynamically self-sustainable than for a random removal. Less connections may even increase the grid’s stability. These facts should be taken into account in the design of future power grids.

  13. The Inheritance of Metabolic Flux: Expressions for the within-Sibship Mean and Variance Given the Parental Genotypes

    PubMed Central

    Ward, P. J.

    1990-01-01

    Recent developments have related quantitative trait expression to metabolic flux. The present paper investigates some implications of this for statistical aspects of polygenic inheritance. Expressions are derived for the within-sibship genetic mean and genetic variance of metabolic flux given a pair of parental, diploid, n-locus genotypes. These are exact and hold for arbitrary numbers of gene loci, arbitrary allelic values at each locus, and for arbitrary recombination fractions between adjacent gene loci. The within-sibship, genetic variance is seen to be simply a measure of parental heterozygosity plus a measure of the degree of linkage coupling within the parental genotypes. Approximations are given for the within-sibship phenotypic mean and variance of metabolic flux. These results are applied to the problem of attaining adequate statistical power in a test of association between allozymic variation and inter-individual variation in metabolic flux. Simulations indicate that statistical power can be greatly increased by augmenting the data with predictions and observations on progeny statistics in relation to parental allozyme genotypes. Adequate power may thus be attainable at small sample sizes, and when allozymic variation is scored at a only small fraction of the total set of loci whose catalytic products determine the flux. PMID:2379825

  14. Combinational Circuit Obfuscation Through Power Signature Manipulation

    DTIC Science & Technology

    2011-06-01

    Algorithm produced by SID . . . . . . . . . . . . . . . . . . . . . . 80 Appendix B . Power Signature Estimation Results 2 . . . . . . . . . . 85 B .1 Power...Signature for c264 Circuit Variant per Algorithm produced by SPICE Simulation . . . . . . . . . . . . . . 85 B .2 Power Signature for c5355 and c499...Smart SSR selecting rear level components and gates with 1000 iterations . . . . . . . . . 84 B .1. Power Signature for c264 By Random Sequence

  15. Advances in high power linearly polarized fiber laser and its application

    NASA Astrophysics Data System (ADS)

    Zhou, Pu; Huang, Long; Ma, Pengfei; Xu, Jiangming; Su, Rongtao; Wang, Xiaolin

    2017-10-01

    Fiber lasers are now attracting more and more research interest due to their advantages in efficiency, beam quality and flexible operation. Up to now, most of the high power fiber lasers have random distributed polarization state. Linearlypolarized (LP) fiber lasers, which could find wide application potential in coherent detection, coherent/spectral beam combining, nonlinear frequency conversion, have been a research focus in recent years. In this paper, we will present a general review on the achievements of various kinds of high power linear-polarized fiber laser and its application. The recent progress in our group, including power scaling by using power amplifier with different mechanism, high power linearly polarized fiber laser with diversified properties, and various applications of high power linear-polarized fiber laser, are summarized. We have achieved 100 Watt level random distributed feedback fiber laser, kilowatt level continuous-wave (CW) all-fiber polarization-maintained fiber amplifier, 600 watt level average power picosecond polarization-maintained fiber amplifier and 300 watt level average power femtosecond polarization-maintained fiber amplifier. In addition, high power linearly polarized fiber lasers have been successfully applied in 5 kilowatt level coherent beam combining, structured light field and ultrasonic generation.

  16. Using variance components to estimate power in a hierarchically nested sampling design improving monitoring of larval Devils Hole pupfish

    USGS Publications Warehouse

    Dzul, Maria C.; Dixon, Philip M.; Quist, Michael C.; Dinsomore, Stephen J.; Bower, Michael R.; Wilson, Kevin P.; Gaines, D. Bailey

    2013-01-01

    We used variance components to assess allocation of sampling effort in a hierarchically nested sampling design for ongoing monitoring of early life history stages of the federally endangered Devils Hole pupfish (DHP) (Cyprinodon diabolis). Sampling design for larval DHP included surveys (5 days each spring 2007–2009), events, and plots. Each survey was comprised of three counting events, where DHP larvae on nine plots were counted plot by plot. Statistical analysis of larval abundance included three components: (1) evaluation of power from various sample size combinations, (2) comparison of power in fixed and random plot designs, and (3) assessment of yearly differences in the power of the survey. Results indicated that increasing the sample size at the lowest level of sampling represented the most realistic option to increase the survey's power, fixed plot designs had greater power than random plot designs, and the power of the larval survey varied by year. This study provides an example of how monitoring efforts may benefit from coupling variance components estimation with power analysis to assess sampling design.

  17. Analysis of entropy extraction efficiencies in random number generation systems

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Han, Zheng-Fu

    2016-05-01

    Random numbers (RNs) have applications in many areas: lottery games, gambling, computer simulation, and, most importantly, cryptography [N. Gisin et al., Rev. Mod. Phys. 74 (2002) 145]. In cryptography theory, the theoretical security of the system calls for high quality RNs. Therefore, developing methods for producing unpredictable RNs with adequate speed is an attractive topic. Early on, despite the lack of theoretical support, pseudo RNs generated by algorithmic methods performed well and satisfied reasonable statistical requirements. However, as implemented, those pseudorandom sequences were completely determined by mathematical formulas and initial seeds, which cannot introduce extra entropy or information. In these cases, “random” bits are generated that are not at all random. Physical random number generators (RNGs), which, in contrast to algorithmic methods, are based on unpredictable physical random phenomena, have attracted considerable research interest. However, the way that we extract random bits from those physical entropy sources has a large influence on the efficiency and performance of the system. In this manuscript, we will review and discuss several randomness extraction schemes that are based on radiation or photon arrival times. We analyze the robustness, post-processing requirements and, in particular, the extraction efficiency of those methods to aid in the construction of efficient, compact and robust physical RNG systems.

  18. Bone-specific gene expression patterns and whole bone tissue of female mice are programmed by early life exposure to soy isoflavones and folic acid.

    PubMed

    Kaludjerovic, Jovana; Ward, Wendy E

    2015-10-01

    Female mice exposed to soy isoflavones (ISO) during early postnatal life have improved bone outcomes at adulthood. Since long-lasting effects may be mediated by DNA methylation, we hypothesized that providing supplemental folic acid (FA), a methyl donor, during early life, would enhance the positive effect of ISO to bone health. Bone-specific gene expression patterns were studied to understand potential mechanisms. CD-1 dams (n=36) were randomized to adequate or supplemental levels of FA (2 or 8 mg/kg diet) during pregnancy and lactation, and offspring received corn oil or ISO (7 mg/kg body weight/d) from postnatal day 1 to 10. From weaning, pups were fed an adequate FA diet and were studied to 4 months of age. Female offspring exposed to supplemental FA+ISO had higher bone mineral density (BMD), trabecular connectivity and peak load at the lumbar spine compared to females exposed to adequate FA. Female offspring exposed to adequate FA+ISO or supplemental FA had higher (P<.05) BMD and greater resistance to fracture at the lumbar spine and the femur; higher trabecular connectivity at the lumbar spine; and lower expression of DNA methyltransferase 3a (Dnmt3a) and neuropeptide Y (NPY) in the femur compared to mice exposed to adequate FA. In addition, only mice exposed to adequate FA+ISO had microstructural improvements at the femur neck and higher serum osteoprotegrin (OPG) and insulin growth factor-I (IGF-I). In summary, exposure to supplemental FA did not enhance the positive effect of ISO in bone. However, exposure to adequate FA+ISO or supplemental FA improved bone at least in part by suppressing Dnmt3a and NPY. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Employing Multilevel Intersectionality in Educational Research: Latino Identities, Contexts, and College Access

    ERIC Educational Resources Information Center

    Núñez, Anne-Marie

    2014-01-01

    The theoretical framework of intersectionality shows much promise in exploring how multiple social identities and their relationships with interlocking systems of power influence educational equity, particularly for historically underserved groups in education. Yet, social scientists have critiqued this framework for not adequately specifying how…

  20. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Lightning arresters, ungrounded and exposed... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.508 Lightning... conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...

  1. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Lightning arresters, ungrounded and exposed... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.508 Lightning... conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...

  2. 30 CFR 77.508 - Lightning arresters, ungrounded and exposed power conductors and telephone wires.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Lightning arresters, ungrounded and exposed... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Electrical Equipment-General § 77.508 Lightning... conductors and telephone wires shall be equipped with suitable lightning arresters which are adequately...

  3. Parents and Nutrition.

    ERIC Educational Resources Information Center

    Boehnlein, Mary Maher

    Parents and the extended family are the most influential factors in the child's lifelong eating habits, general health and development, and brain power. Convincing parents of diet components that insure adequate nutrition is of prime importance; if the home does not support the content of the school's nutritional curriculum, the child may feel…

  4. 76 FR 77565 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses Involving No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ... assure that the emergency diesel generator's diesel driven cooling water pumps perform their required... generators will provide required electrical power as assumed in the accident analyses and the cooling water... Technical Specifications to require an adequate emergency diesel generator and diesel driven cooling water...

  5. 78 FR 15054 - Agency Information Collection Activities: Proposed Collection; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... nuclear materials to ensure adequate protection of public health and safety, to promote the common defense and security, and to protect the environment. One way to support this mission is through the... assess the safety performance of commercial nuclear power plants and to respond to any decline in...

  6. The Quest for Powerful Learning Environments in Higher Education

    ERIC Educational Resources Information Center

    Slabbert, J. A.; Gouws, D. G.

    2006-01-01

    An introductory course in on tertiary level inadvertently sets the scene for the demands of the corresponding profession. Unfortunately, it seems as though these courses do not prepare learners adequately to acquire the demanding professional competences required for professional success. This problem has been a subject of contention especially in…

  7. 40 CFR 63.11410 - What are the compliance requirements?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the proper functioning of the electronic controls for corona power and rapper operation, that the corona wires are energized, and that adequate air pressure is present on the rapper manifold. You must... integrity of corona wires, collection plates, hopper, and air diffuser plates. An initial inspection of the...

  8. 40 CFR 63.11410 - What are the compliance requirements?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the proper functioning of the electronic controls for corona power and rapper operation, that the corona wires are energized, and that adequate air pressure is present on the rapper manifold. You must... integrity of corona wires, collection plates, hopper, and air diffuser plates. An initial inspection of the...

  9. 40 CFR 63.11410 - What are the compliance requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the proper functioning of the electronic controls for corona power and rapper operation, that the corona wires are energized, and that adequate air pressure is present on the rapper manifold. You must... integrity of corona wires, collection plates, hopper, and air diffuser plates. An initial inspection of the...

  10. 40 CFR 63.11410 - What are the compliance requirements?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the proper functioning of the electronic controls for corona power and rapper operation, that the corona wires are energized, and that adequate air pressure is present on the rapper manifold. You must... integrity of corona wires, collection plates, hopper, and air diffuser plates. An initial inspection of the...

  11. 40 CFR 63.11410 - What are the compliance requirements?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the proper functioning of the electronic controls for corona power and rapper operation, that the corona wires are energized, and that adequate air pressure is present on the rapper manifold. You must... integrity of corona wires, collection plates, hopper, and air diffuser plates. An initial inspection of the...

  12. Educational Auditing and Quality Assurance. Occasional Paper No. 4.

    ERIC Educational Resources Information Center

    Conner, James E.; Lessinger, Leon M.

    This paper considers how to respond to new requirements for adequate disclosure of the schools' performance to the public. It proposes the use of three powerful constructs--quality control, quality assurance, and an independent educational accomplishment audit (IEAA). The essential elements of quality control are agreeing on and specifying desired…

  13. 77 FR 21594 - Duke Energy Carolinas, LLC; Environmental Assessment and Finding of No Significant Impact, Oconee...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... of light-water nuclear power reactors provide adequate margins of safety during any condition of... toughness requirements for protection against pressurized thermal shock (PTS) events. The proposed action... for Protection Against Pressurized Thermal Shock Events,'' and 10 CFR part 50 Appendix G, ``Fracture...

  14. Research@ARL: Network Sciences

    DTIC Science & Technology

    2013-03-01

    and Power Allocation for Minimum Energy Consumption in Consensus Networks ................ 21 Stefania Sardellitti, Sergio Barbarossa, and Ananthram...battlefield effectiveness and to ensure that Soldier performance requirements are adequately considered in technology development and system design...Operations (NCO). NCW/NCO seeks to dramatically increase mission effectiveness via robust networking for information sharing leading to shared

  15. Safe Passage

    ERIC Educational Resources Information Center

    Razwick, Jeff

    2007-01-01

    Many schools are almost entirely reliant on alarms and sprinklers for their fire protection. As these devices need to be triggered and supplied with power or water to work properly, they are vulnerable to errors. To provide adequate safety, a good fire-protection program must have three primary elements: fire protection and suppression, and…

  16. To amend the Federal Power Act to provide additional authorities to adequately protect the critical electric infrastructure against cyber attack, and for other purposes.

    THOMAS, 111th Congress

    Rep. Thompson, Bennie G. [D-MS-2

    2009-04-30

    House - 05/26/2009 Referred to the Subcommittee on Emerging Threats, Cybersecurity, and Science and Technology. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  17. 47 CFR 74.781 - Station records.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Booster Stations § 74.781 Station records. (a) The licensee of a low power TV, TV translator, or TV booster station shall maintain adequate station records, including the current instrument of authorization... other suitable place, in one of the communities of license of the translator or booster, except that the...

  18. 47 CFR 74.781 - Station records.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Booster Stations § 74.781 Station records. (a) The licensee of a low power TV, TV translator, or TV booster station shall maintain adequate station records, including the current instrument of authorization... other suitable place, in one of the communities of license of the translator or booster, except that the...

  19. 47 CFR 74.781 - Station records.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Booster Stations § 74.781 Station records. (a) The licensee of a low power TV, TV translator, or TV booster station shall maintain adequate station records, including the current instrument of authorization... other suitable place, in one of the communities of license of the translator or booster, except that the...

  20. 47 CFR 74.781 - Station records.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Booster Stations § 74.781 Station records. (a) The licensee of a low power TV, TV translator, or TV booster station shall maintain adequate station records, including the current instrument of authorization... other suitable place, in one of the communities of license of the translator or booster, except that the...

  1. 49 CFR 178.338-17 - Pumps and compressors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.338-17 Pumps and compressors. (a) Liquid pumps and gas compressors, if used, must be of suitable design, adequately protected against breakage by collision, and kept in good condition. They may be driven by motor vehicle power take...

  2. 49 CFR 178.337-15 - Pumps and compressors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.337-15 Pumps and compressors. (a) Liquid pumps or gas compressors, if used, must be of suitable design, adequately protected against breakage by collision, and kept in good condition. They may be driven by motor vehicle power take...

  3. Principals, Power, and Policy: Enacting "Supplemental Educational Services"

    ERIC Educational Resources Information Center

    Koyama, Jill

    2011-01-01

    Under No Child Left Behind (NCLB), schools that do not make adequate yearly progress must offer afterschool tutoring, entitled "Supplemental Educational Services" (SES). Drawing on 40 months of ethnographic research and utilizing actor-network theory, this article shows principals co-opting the SES provisions to do what they determine is…

  4. Signal Detection Theory as a Tool for Successful Student Selection

    ERIC Educational Resources Information Center

    van Ooijen-van der Linden, Linda; van der Smagt, Maarten J.; Woertman, Liesbeth; te Pas, Susan F.

    2017-01-01

    Prediction accuracy of academic achievement for admission purposes requires adequate "sensitivity" and "specificity" of admission tools, yet the available information on the validity and predictive power of admission tools is largely based on studies using correlational and regression statistics. The goal of this study was to…

  5. 46 CFR 56.50-1 - General (replaces 122).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... maintenance of machinery and appurtenances. The joints shall be located so that adequate space is provided for... Safety Center. All power actuated valves required in an emergency to operate the vessel's machinery, to... liquids, except that tank barges having plug cocks inside cargo tanks may have reach rods of extra-heavy...

  6. 77 FR 39745 - Fuel Oil Systems for Emergency Power Supplies

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... fuel oil systems for safety-related emergency diesel generators and oil-fueled gas turbine generators... emergency diesel generators and oil-fueled gas turbine generators, including assurance of adequate fuel oil.... The DG-1282 is proposed revision 2 of Regulatory Guide 1.137, ``Fuel Oil Systems for Standby Diesel...

  7. Is Neurofeedback an Efficacious Treatment for ADHD? A Randomised Controlled Clinical Trial

    ERIC Educational Resources Information Center

    Gevensleben, Holger; Holl, Birgit; Albrecht, Bjorn; Vogel, Claudia; Schlamp, Dieter; Kratz, Oliver; Studer, Petra; Rothenberger, Aribert; Moll, Gunther H.; Heinrich, Hartmut

    2009-01-01

    Background: For children with attention deficit/hyperactivity disorder (ADHD), a reduction of inattention, impulsivity and hyperactivity by neurofeedback (NF) has been reported in several studies. But so far, unspecific training effects have not been adequately controlled for andor studies do not provide sufficient statistical power. To overcome…

  8. 14 CFR 23.1143 - Engine controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... independent of those for every other engine or supercharger. (e) For each fluid injection (other than fuel... flow of the injection fluid is adequately controlled. (f) If a power, thrust, or a fuel control (other than a mixture control) incorporates a fuel shutoff feature, the control must have a means to prevent...

  9. 14 CFR 23.1143 - Engine controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... independent of those for every other engine or supercharger. (e) For each fluid injection (other than fuel... flow of the injection fluid is adequately controlled. (f) If a power, thrust, or a fuel control (other than a mixture control) incorporates a fuel shutoff feature, the control must have a means to prevent...

  10. The CO2 laser frequency stability measurements

    NASA Technical Reports Server (NTRS)

    Johnson, E. H., Jr.

    1973-01-01

    Carbon dioxide laser frequency stability data are considered for a receiver design that relates to maximum Doppler frequency and its rate of change. Results show that an adequate margin exists in terms of data acquisition, Doppler tracking, and bit error rate as they relate to laser stability and transmitter power.

  11. Physical Properties and Durability of New Materials for Space and Commercial Applications

    NASA Technical Reports Server (NTRS)

    Hambourger, Paul D.

    2003-01-01

    To develop and test new materials for use in space power systems and related space and commercial applications, to assist industry in the application of these materials, and to achieve an adequate understanding of the mechanisms by which the materials perform in their intended applications.

  12. Slush hydrogen liquid level system

    NASA Technical Reports Server (NTRS)

    Hamlet, J. F.; Adams, R. G.

    1972-01-01

    A discrete capacitance liquid level system developed is specifically for slush hydrogen, but applicable to LOX, LN2, LH2, and RP1 without modification is described. The signal processing portion of the system is compatible with conventional liquid level sensors. Compatibility with slush hydrogen was achieved by designing the sensor with adequate spacing, while retaining the electrical characteristics of conventional sensors. Tests indicate excellent stability of the system over a temperature range of -20 C to 70 C for the circuit and to cryogenic temperatures of the sensor. The sensor was tested up to 40 g's rms random vibration with no damage to the sensor. Operation with 305 m of cable between the sensor and signal processor was demonstrated. It is concluded that this design is more than adequate for most flight and ground applications.

  13. Measures of rowing performance.

    PubMed

    Smith, T Brett; Hopkins, Will G

    2012-04-01

    Accurate measures of performance are important for assessing competitive athletes in practi~al and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.

  14. Surgical treatment of secondary peritonitis : A continuing problem.

    PubMed

    van Ruler, O; Boermeester, M A

    2017-01-01

    Secondary peritonitis remains associated with high mortality and morbidity rates. Treatment of secondary peritonitis is challenging even in modern medicine. Surgical intervention for source control remains the cornerstone of treatment, beside adequate antimicrobial therapy and resuscitation. A randomized clinical trial showed that relaparotomy on demand (ROD) after initial emergency surgery is the preferred treatment strategy, irrespective of the severity and extent of peritonitis. The effective and safe use of ROD requires intensive monitoring of the patient in a setting where diagnostic tests and decision making about relaparotomy are guaranteed round the clock. The lack of knowledge on timely and adequate patient selection, together with the lack of use of easy but reliable monitoring tools, seems to hamper full implementation of ROD. The accuracy of the relap decision tool is reasonable for prediction of ongoing peritonitis and selection for computer tomography (CT). The value of CT in an early postoperative phase is unclear. Future research and innovative technologies should focus on the additive value of CT in cases of operated secondary peritonitis and on the further optimization of bedside prediction tools to enhance adequate patient selection for intervention in a multidisciplinary setting.

  15. The effect of time on CPR and automated external defibrillator skills in the Public Access Defibrillation Trial

    PubMed Central

    Christenson, Jim; Nafziger, Sarah; Compton, Scott; Vijayaraghavan, Kris; Slater, Brian; Ledingham, Robert; Powell, Judy; McBurnie, Mary Ann

    2009-01-01

    Background The time to skill deterioration between primary training/retraining and further retraining in Cardiopulmonary resuscitation (CPR) and automated external defibrillation (AED) for lay-persons is unclear. The Public Access Defibrillation (PAD) Trial was a multi-center randomized controlled trial evaluating survival after CPR-only vs. CPR+AED delivered by onsite non-medical volunteer responders in out-of-hospital cardiac arrest. Aims This sub-study evaluated the relationship of time between primary training/retraining and further retraining on volunteer performance during pretest AED and CPR skill evaluation. Methods Volunteers at 1260 facilities in 24 North American regions underwent training/retraining according to facility randomization, which included an initial session and a refresher session at approximately 6 months. Before the next retraining, a CPR and AED skill test was completed for 2729 volunteers. Primary outcome for the study was assessment of global competence of CPR or AED performance (adequate vs not adequate) using Chi-square tests for trends by time interval (3, 6, 9, and 12 months). Confirmatory (GEE) logistic regression analysis, adjusted for site and potential confounders. Results The proportion of volunteers judged to be competent did not diminish by interval (3,6,9,12 months) for either CPR or AED skills. After adjusting for site and potential confounders, longer intervals before to further retraining was associated with a slightly lower likelihood of performing adequate CPR but not with AED scores. Conclusions After primary training/retraining, the CPR skills of targeted lay responders deteriorate nominally but 80% remain competent up to one year. AED skills do not significantly deteriorate and 90% of volunteers remain competent up to one year. PMID:17303309

  16. Comparing the efficacy and safety between propofol and dexmedetomidine for sedation in claustrophobic adults undergoing magnetic resonance imaging (PADAM trial).

    PubMed

    Loh, Pui-San; Ariffin, Mohd Azlan; Rai, Vineya; Lai, Lee-Lee; Chan, Lucy; Ramli, Norlisah

    2016-11-01

    To determine the efficacy of sedation with dexmedetomidine compared to propofol for claustrophobic adults undergoing magnetic resonance imaging (MRI) in our institution. Randomized, prospective, double-blinded study. University-based tertiary referral center. Thirty claustrophobic adults with American Society of Anesthesiologists physical status I and II who were planned for MRI. Patients were randomly assigned to target-controlled infusion propofol or dexmedetomidine loading followed by maintenance dose for procedural sedation. The primary end point was adequate reduction in patient anxiety levels to allow successful completion of the MRI sequence. Both methods of sedation adequately reduced anxiety levels in visual analog scale scores and Spielberger Strait Test Anxiety Inventory (P<.001). Dexmedetomidine required a longer time to achieve anxiolysis, 7.36minutes (SD, 2.59), and required increasing maintenance dose to induce sleep compared to 10.71minutes (SD, 4.63) for propofol. In terms of image quality, 2 patients (16.67%) in the dexmedetomidine group were satisfactory, whereas all with propofol were graded as good to excellent. Adverse effects were seen in patients sedated with dexmedetomidine with number needed to harm 8 for hypotension and 15 for bradycardia compared to none recorded in the propofol arm. There was no significant difference in patient satisfaction scores or home readiness after the MRI. Both dexmedetomidine and propofol can effectively reduce anxiety levels of claustrophobic adults undergoing MRI, but dexmedetomidine takes longer to achieve adequate anxiolysis and sleep and may have an effect on image quality. Hypotension and bradycardia are common adverse effects observed with dexmedetomidine. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects.

    PubMed

    Davis, Michelle L; Papini, Santiago; Rosenfield, David; Roelofs, Karin; Kolb, Sarah; Powers, Mark B; Smits, Jasper A J

    2017-12-01

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD were assigned to one of three conditions: power posing, submissive posing, or rest (no posing) prior to participating in an exposure therapy session. Participants were assessed for between-group differences in pre- and post-manipulation salivary hormone levels, within-session subjective experiences of fear, and pre- and 1-week post-treatment SAD severity outcome measures. Though the intervention resulted in decreased SAD symptom severity one week later, analyses revealed no significant between-group differences on any tested variables. Accordingly, this study provides no evidence to suggest that power posing impacts hormone levels or exposure therapy outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Time-varying output performances of piezoelectric vibration energy harvesting under nonstationary random vibrations

    NASA Astrophysics Data System (ADS)

    Yoon, Heonjun; Kim, Miso; Park, Choon-Su; Youn, Byeng D.

    2018-01-01

    Piezoelectric vibration energy harvesting (PVEH) has received much attention as a potential solution that could ultimately realize self-powered wireless sensor networks. Since most ambient vibrations in nature are inherently random and nonstationary, the output performances of PVEH devices also randomly change with time. However, little attention has been paid to investigating the randomly time-varying electroelastic behaviors of PVEH systems both analytically and experimentally. The objective of this study is thus to make a step forward towards a deep understanding of the time-varying performances of PVEH devices under nonstationary random vibrations. Two typical cases of nonstationary random vibration signals are considered: (1) randomly-varying amplitude (amplitude modulation; AM) and (2) randomly-varying amplitude with randomly-varying instantaneous frequency (amplitude and frequency modulation; AM-FM). In both cases, this study pursues well-balanced correlations of analytical predictions and experimental observations to deduce the relationships between the time-varying output performances of the PVEH device and two primary input parameters, such as a central frequency and an external electrical resistance. We introduce three correlation metrics to quantitatively compare analytical prediction and experimental observation, including the normalized root mean square error, the correlation coefficient, and the weighted integrated factor. Analytical predictions are in an excellent agreement with experimental observations both mechanically and electrically. This study provides insightful guidelines for designing PVEH devices to reliably generate electric power under nonstationary random vibrations.

  19. Random Walks on Cartesian Products of Certain Nonamenable Groups and Integer Lattices

    NASA Astrophysics Data System (ADS)

    Vishnepolsky, Rachel

    A random walk on a discrete group satisfies a local limit theorem with power law exponent \\alpha if the return probabilities follow the asymptotic law. P{ return to starting point after n steps } ˜ Crhonn-alpha.. A group has a universal local limit theorem if all random walks on the group with finitely supported step distributions obey a local limit theorem with the same power law exponent. Given two groups that obey universal local limit theorems, it is not known whether their cartesian product also has a universal local limit theorem. We settle the question affirmatively in one case, by considering a random walk on the cartesian product of a nonamenable group whose Cayley graph is a tree, and the integer lattice. As corollaries, we derive large deviations estimates and a central limit theorem.

  20. How we became the Schmams: conceptualizations of fairness in the decision-making process for Latina/o children.

    PubMed

    Langhout, Regina Day; Kohfeldt, Danielle M; Ellison, Erin Rose

    2011-12-01

    The current study examines 16 Latina/o fifth grade children's desires for a decision-making structure within a youth participatory action research (yPAR) program. When given the choices of consensus, majority rule, authoritarian rule, delegation, and random choice models, children chose random choice. Procedural, distributive and emotional justice were heavily weighted in their reasoning around fairness and decision making. Many thought random choice offered the best alternative because it flattened power hierarchies so that each child would, at some point, have the power to make a decision. Additionally, children argued that the neutrality of random choice allowed them to sidestep interpersonal tensions. Implications include how social identities inform definitions of fairness and how yPAR programs should work with youth around how they will make decisions.

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