Use of Matrix Sampling Procedures to Assess Achievement in Solving Open Addition and Subtraction Sentences.

ERIC Educational Resources Information Center

Montague, Margariete A.

This study investigated the feasibility of concurrently and randomly sampling examinees and items in order to estimate group achievement. Seven 32-item tests reflecting a 640-item universe of simple open sentences were used such that item selection (random, systematic) and assignment (random, systematic) of items (four, eight, sixteen) to forms…

Chaos Modeling: Increasing Educational Researchers' Awareness of a New Tool.

ERIC Educational Resources Information Center

Bobner, Ronald F.; And Others

Chaos theory is being used as a tool to study a wide variety of phenomena. It is a philosophical and empirical approach that attempts to explain relationships previously thought to be totally random. Although some relationships are truly random, many data appear to be random but reveal repeatable patterns of behavior under further investigation.…

Effects of unstratified and centre-stratified randomization in multi-centre clinical trials.

PubMed

Anisimov, Vladimir V

2011-01-01

This paper deals with the analysis of randomization effects in multi-centre clinical trials. The two randomization schemes most often used in clinical trials are considered: unstratified and centre-stratified block-permuted randomization. The prediction of the number of patients randomized to different treatment arms in different regions during the recruitment period accounting for the stochastic nature of the recruitment and effects of multiple centres is investigated. A new analytic approach using a Poisson-gamma patient recruitment model (patients arrive at different centres according to Poisson processes with rates sampled from a gamma distributed population) and its further extensions is proposed. Closed-form expressions for corresponding distributions of the predicted number of the patients randomized in different regions are derived. In the case of two treatments, the properties of the total imbalance in the number of patients on treatment arms caused by using centre-stratified randomization are investigated and for a large number of centres a normal approximation of imbalance is proved. The impact of imbalance on the power of the study is considered. It is shown that the loss of statistical power is practically negligible and can be compensated by a minor increase in sample size. The influence of patient dropout is also investigated. The impact of randomization on predicted drug supply overage is discussed. Copyright © 2010 John Wiley & Sons, Ltd.

A Randomized Controlled Trial of Exposure Therapy and Cognitive Restructuring for Posttraumatic Stress Disorder

ERIC Educational Resources Information Center

Bryant, Richard A.; Moulds, Michelle L.; Guthrie, Rachel M.; Dang, Suzanne T.; Mastrodomenico, Julie; Nixon, Reginald D. V.; Felmingham, Kim L.; Hopwood, Sally; Creamer, Mark

2008-01-01

Previous studies have reported that adding cognitive restructuring (CR) to exposure therapy does not enhance treatment gains in posttraumatic stress disorder (PTSD). This study investigated the extent to which CR would augment treatment response when provided with exposure therapy. The authors randomly allocated 118 civilian trauma survivors with…

Complete convergence of randomly weighted END sequences and its application.

PubMed

Li, Penghua; Li, Xiaoqin; Wu, Kehan

2017-01-01

We investigate the complete convergence of partial sums of randomly weighted extended negatively dependent (END) random variables. Some results of complete moment convergence, complete convergence and the strong law of large numbers for this dependent structure are obtained. As an application, we study the convergence of the state observers of linear-time-invariant systems. Our results extend the corresponding earlier ones.

Scaling characteristics of one-dimensional fractional diffusion processes in the presence of power-law distributed random noise

NASA Astrophysics Data System (ADS)

Nezhadhaghighi, Mohsen Ghasemi

2017-08-01

Here, we present results of numerical simulations and the scaling characteristics of one-dimensional random fluctuations with heavy-tailed probability distribution functions. Assuming that the distribution function of the random fluctuations obeys Lévy statistics with a power-law scaling exponent, we investigate the fractional diffusion equation in the presence of μ -stable Lévy noise. We study the scaling properties of the global width and two-point correlation functions and then compare the analytical and numerical results for the growth exponent β and the roughness exponent α . We also investigate the fractional Fokker-Planck equation for heavy-tailed random fluctuations. We show that the fractional diffusion processes in the presence of μ -stable Lévy noise display special scaling properties in the probability distribution function (PDF). Finally, we numerically study the scaling properties of the heavy-tailed random fluctuations by using the diffusion entropy analysis. This method is based on the evaluation of the Shannon entropy of the PDF generated by the random fluctuations, rather than on the measurement of the global width of the process. We apply the diffusion entropy analysis to extract the growth exponent β and to confirm the validity of our numerical analysis.

Scaling characteristics of one-dimensional fractional diffusion processes in the presence of power-law distributed random noise.

PubMed

Nezhadhaghighi, Mohsen Ghasemi

2017-08-01

Here, we present results of numerical simulations and the scaling characteristics of one-dimensional random fluctuations with heavy-tailed probability distribution functions. Assuming that the distribution function of the random fluctuations obeys Lévy statistics with a power-law scaling exponent, we investigate the fractional diffusion equation in the presence of μ-stable Lévy noise. We study the scaling properties of the global width and two-point correlation functions and then compare the analytical and numerical results for the growth exponent β and the roughness exponent α. We also investigate the fractional Fokker-Planck equation for heavy-tailed random fluctuations. We show that the fractional diffusion processes in the presence of μ-stable Lévy noise display special scaling properties in the probability distribution function (PDF). Finally, we numerically study the scaling properties of the heavy-tailed random fluctuations by using the diffusion entropy analysis. This method is based on the evaluation of the Shannon entropy of the PDF generated by the random fluctuations, rather than on the measurement of the global width of the process. We apply the diffusion entropy analysis to extract the growth exponent β and to confirm the validity of our numerical analysis.

Design and analysis of group-randomized trials in cancer: A review of current practices.

PubMed

Murray, David M; Pals, Sherri L; George, Stephanie M; Kuzmichev, Andrey; Lai, Gabriel Y; Lee, Jocelyn A; Myles, Ranell L; Nelson, Shakira M

2018-06-01

The purpose of this paper is to summarize current practices for the design and analysis of group-randomized trials involving cancer-related risk factors or outcomes and to offer recommendations to improve future trials. We searched for group-randomized trials involving cancer-related risk factors or outcomes that were published or online in peer-reviewed journals in 2011-15. During 2016-17, in Bethesda MD, we reviewed 123 articles from 76 journals to characterize their design and their methods for sample size estimation and data analysis. Only 66 (53.7%) of the articles reported appropriate methods for sample size estimation. Only 63 (51.2%) reported exclusively appropriate methods for analysis. These findings suggest that many investigators do not adequately attend to the methodological challenges inherent in group-randomized trials. These practices can lead to underpowered studies, to an inflated type 1 error rate, and to inferences that mislead readers. Investigators should work with biostatisticians or other methodologists familiar with these issues. Funders and editors should ensure careful methodological review of applications and manuscripts. Reviewers should ensure that studies are properly planned and analyzed. These steps are needed to improve the rigor and reproducibility of group-randomized trials. The Office of Disease Prevention (ODP) at the National Institutes of Health (NIH) has taken several steps to address these issues. ODP offers an online course on the design and analysis of group-randomized trials. ODP is working to increase the number of methodologists who serve on grant review panels. ODP has developed standard language for the Application Guide and the Review Criteria to draw investigators' attention to these issues. Finally, ODP has created a new Research Methods Resources website to help investigators, reviewers, and NIH staff better understand these issues. Published by Elsevier Inc.

An Experimental Study of Interventions for the Acquisition and Retention of Motivational Interviewing Skills among Probation Officers

ERIC Educational Resources Information Center

Asteris, Mark M., Jr.

2012-01-01

This study was designed to investigate the differences in Motivational Interviewing (MI) skill acquisition and retention among probation officers. This study had a randomized, experimental, pretest-posttest control group design using the MITI 3.1.1 and the VASE-R to measure MI skill acquisition and retention. A random sample (n = 24) of probation…

The Effects of Self- and Peer-Monitoring in Social Studies Performance of Students with Learning Disabilities and Low Achieving Students

ERIC Educational Resources Information Center

Kim, Woori; Ok, Min Wook; Yoo, Yongseok

2018-01-01

This study employed group randomized trials to investigate the effects of self- and peer-monitoring on the academic vocabulary and content knowledge of students with learning disabilities and low achieving students in social studies. Fourth grade students were randomly assigned to either treatment or control groups on a class level. Results…

The Effects of Improvisational Music Therapy on Joint Attention Behaviors in Autistic Children: A Randomized Controlled Study

ERIC Educational Resources Information Center

Kim, Jinah; Wigram, Tony; Gold, Christian

2008-01-01

The purpose of this study was to investigate the effects of improvisational music therapy on joint attention behaviors in pre-school children with autism. It was a randomized controlled study employing a single subject comparison design in two different conditions, improvisational music therapy and play sessions with toys, and using standardized…

A randomized, phase II study of pazopanib in castrate-sensitive prostate cancer: a University of Chicago Phase II Consortium/Department of Defense Prostate Cancer Clinical Trials Consortium study.

PubMed

Ward, J E; Karrison, T; Chatta, G; Hussain, M; Shevrin, D; Szmulewitz, R Z; O'Donnell, P H; Stadler, W M; Posadas, E M

2012-03-01

Intermittent androgen suppression (IAS) is an increasingly popular treatment option for castrate-sensitive prostate cancer. On the basis of previous data with anti-angiogenic strategies, we hypothesized that pan-inhibition of the vascular endothelial growth factor receptor using pazopanib during the IAS off period would result in prolonged time to PSA failure. Men with biochemically recurrent prostate cancer, whose PSA was <0.5 ng ml(-1) after 6 months of androgen deprivation therapy were randomized to pazopanib 800 mg daily or observation. The planned primary outcome was time to PSA progression >4.0 ng ml(-1). Thirty-seven patients were randomized. Of 18 patients randomized to pazopanib, at the time of study closure, 4 had progressive disease, 1 remained on treatment and 13 (72%) electively disenrolled, the most common reason being patient request due to grade 1/2 toxicity (8 patients). Two additional patients were removed from treatment due to adverse events. Of 19 patients randomized to observation, at the time of study closure, 4 had progressive disease, 7 remained under protocol-defined observation and 8 (42%) had disenrolled, most commonly due to non-compliance with protocol visits (3 patients). Because of high dropout rates in both arms, the study was halted. IAS is a treatment approach that may facilitate investigation of novel agents in the hormone-sensitive state. This trial attempted to investigate the role of antiangiogenic therapy in this setting, but encountered several barriers, including toxicities and patient non-compliance, which can make implementation of such a study difficult. Future investigative efforts in this arena should carefully consider drug toxicity and employ a design that maximizes patient convenience to reduce the dropout rate.

The Random Forests Statistical Technique: An Examination of Its Value for the Study of Reading

ERIC Educational Resources Information Center

Matsuki, Kazunaga; Kuperman, Victor; Van Dyke, Julie A.

2016-01-01

Studies investigating individual differences in reading ability often involve data sets containing a large number of collinear predictors and a small number of observations. In this article, we discuss the method of Random Forests and demonstrate its suitability for addressing the statistical concerns raised by such data sets. The method is…

The Role of Exposure Condition in the Effectiveness of Explicit Correction

ERIC Educational Resources Information Center

Yilmaz, Yucel

2016-01-01

This article reports on a study that investigated the effects of two feedback exposure conditions on the acquisition of two Turkish morphemes. The study followed a randomized experimental design with an immediate and a delayed posttest. Forty-two Chinese-speaking learners of Turkish were randomly assigned to one of three groups: receivers,…

The Relationship between Teachers Commitment and Female Students Academic Achievements in Some Selected Secondary School in Wolaita Zone, Southern Ethiopia

ERIC Educational Resources Information Center

Bibiso, Abyot; Olango, Menna; Bibiso, Mesfin

2017-01-01

The purpose of this study was to investigate the relationship between teacher's commitment and female students academic achievement in selected secondary school of Wolaita zone, Southern Ethiopia. The research method employed was survey study and the sampling techniques were purposive, simple random and stratified random sampling. Questionnaire…

Cervical Spondylotic Myelopathy Surgical (CSM-S) Trial: Randomized Controlled Trial Design and Rationale

PubMed Central

Ghogawala, Zoher; Benzel, Edward C.; Heary, Robert F.; Riew, K. Daniel; Albert, Todd J.; Butler, William E.; Barker, Fred G.; Heller, John G.; McCormick, Paul C.; Whitmore, Robert G.; Freund, Karen M.; Schwartz, J. Sanford

2014-01-01

Background Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in the world. There is significant practice variation and uncertainty as to the optimal surgical approach for treating CSM. Objective The primary objective is to determine if ventral surgery is associated with superior SF-36 Physical Component Summary (PCS) outcome at one year follow-up compared to dorsal (laminectomy/fusion or laminoplasty) surgery for the treatment of CSM. The study will also investigate whether post-operative sagittal balance is an independent predictor of overall outcome and will compare health resource utilization for ventral and dorsal procedures. Methods The study is a randomized, controlled trial with a nonrandomized arm for patients who are eligible but decline randomization. Two hundred fifty patients (159 randomized) with CSM from 11 sites will be recruited over 18 months. The primary outcome is the Short Form-36 PCS score. Secondary outcomes include disease specific outcomes, overall health-related quality of life (EuroQol-5D), and health resource utilization. Expected Outcomes This will be the first randomized controlled trial to compare directly the health-related quality of life outcomes for ventral versus dorsal surgery for treating CSM. Discussion An NIH-funded (1R13AR065834-01) investigator meeting was held prior to initiating the trial in order to bring multiple stakeholders together to finalize the study protocol. Study investigators, coordinators, and major stakeholders were able to attend and discuss strengths, limitations, and concerns regarding the study. The final protocol was approved for funding by PCORI (CE-1304-6173). The RCT began enrollment on April 1, 2014. PMID:24991714

Effect of Peer-Led Team Learning (PLTL) on Student Achievement, Attitude, and Self-Concept in College General Chemistry in Randomized and Quasi Experimental Designs

ERIC Educational Resources Information Center

Chan, Julia Y. K.; Bauer, Christopher F.

2015-01-01

This study investigated exam achievement and affective characteristics of students in general chemistry in a fully-randomized experimental design, contrasting Peer-Led Team Learning (PLTL) participation with a control group balanced for time-on-task and study activity. This study population included two independent first-semester courses with…

Experiences of randomization: interviews with patients and clinicians in the SPCG-IV trial.

PubMed

Bill-Axelson, Anna; Christensson, Anna; Carlsson, Marianne; Norlén, Bo Johan; Holmberg, Lars

2008-01-01

Recruitment of both patients and clinicians to randomized trials is difficult. Low participation carries the risk of terminating studies early and making them invalid owing to insufficient statistical power. This study investigated patients' and clinicians' experiences of randomization with the aim of facilitating trial participation in the future. This was a qualitative study using content analysis. Patients offered to participate in a randomized trial and randomizing clinicians were interviewed. Five participants, four non-participants and five randomizing clinicians were interviewed, 2-8 years from randomization. Clinicians used strategies in interaction with the patients to facilitate decision making. Patients' attitudes differed and experiences of relatives or friends were often stated as reasons for treatment preferences. Patients described that letting chance decide treatment was a difficult barrier to overcome for randomization. The clinicians used a number of different strategies perceived to make randomization more acceptable to their patients. The clinicians' own motivation for randomizing patients for trials depended on the medical relevance of the study question and the clinicians' major obstacle was to maintain equipoise over time. Regular meetings with the study group helped to maintain equipoise and motivation. To establish a good platform for randomization the clinician needs to know about the patient's treatment preferences and the patient's attitude concerning the role of the clinician to facilitate decision making. The strategies used by the clinicians were perceived as helpful and could be tested in an intervention study.

Hierarchy of evidence: differences in results between non-randomized studies and randomized trials in patients with femoral neck fractures.

PubMed

Bhandari, Mohit; Tornetta, Paul; Ellis, Thomas; Audige, Laurent; Sprague, Sheila; Kuo, Jonathann C; Swiontkowski, Marc F

2004-01-01

There have been a number of non-randomized studies comparing arthroplasty with internal fixation in patients with femoral neck fractures. However, there remains considerable debate about whether the results of non-randomized studies are consistent with the results of randomized, controlled trials. Given the economic burden of hip fractures, it remains essential to identify therapies to improve outcomes; however, whether data from non-randomized studies of an intervention should be used to guide patient care remains unclear. We aimed to determine whether the pooled results of mortality and revision surgery among non-randomized studies were similar to those of randomized trials in studies comparing arthroplasty with internal fixation in patients with femoral neck fractures. We conducted a Medline search from 1969 to June 2002, identifying both randomized and non-randomized studies comparing internal fixation with arthroplasty in patients with femoral neck fractures. Additional strategies to identify relevant articles included Cochrane database, SCISEARCH, textbooks, annual meeting programs, and content experts. We abstracted information on mortality and revision rates in each study and compared the pooled results between non-randomized and randomized studies. In addition, we explored potential reasons for dissimilar results between the two study designs. We identified 140 citations that addressed the general topic of comparison of arthroplasty and internal fixation for hip fracture. Of these, 27 studies met the eligibility criteria, 13 of which were non-randomized studies and 14 of which were randomized trials. Mortality data was available in all 13 non-randomized studies ( n=3108 patients) and in 12 randomized studies ( n=1767 patients). Non-randomized studies overestimated the risk of mortality by 40% when compared with the results of randomized trials (relative risk 1.44 vs 1.04, respectively). Information on revision risk was available in 9 non-randomized studies ( n=2764 patients) and all 14 randomized studies ( n=1901 patients). Both estimates from non-randomized and randomized studies revealed a significant reduction in the risk of revision surgery with arthroplasty compared with internal fixation (relative risk 0.38 vs 0.23, respectively). The reduction in the risk of revision surgery with arthroplasty compared with internal fixation was 62% for non-randomized studies and 77% for randomized trials. Thus, non-randomized studies underestimated the relative benefit of arthroplasty by 19.5%. Non-randomized studies with point estimates of relative risk similar to the pooled estimate for randomized trials all controlled for patient age, gender, and fracture displacement in their comparisons of mortality. We were unable to identify reasons for differences in the revision rate results between the study designs. Similar to other reports in medical subspecialties, non-randomized studies provided results dissimilar to randomized trials of arthroplasty vs internal fixation for mortality and revision rates in patients with femoral neck fractures. Investigators should be aware of these discrepancies when evaluating the merits of alternative surgical interventions, especially when both randomized trials and non-randomized comparative studies are available.

Tissue segmentation of computed tomography images using a Random Forest algorithm: a feasibility study

NASA Astrophysics Data System (ADS)

Polan, Daniel F.; Brady, Samuel L.; Kaufman, Robert A.

2016-09-01

There is a need for robust, fully automated whole body organ segmentation for diagnostic CT. This study investigates and optimizes a Random Forest algorithm for automated organ segmentation; explores the limitations of a Random Forest algorithm applied to the CT environment; and demonstrates segmentation accuracy in a feasibility study of pediatric and adult patients. To the best of our knowledge, this is the first study to investigate a trainable Weka segmentation (TWS) implementation using Random Forest machine-learning as a means to develop a fully automated tissue segmentation tool developed specifically for pediatric and adult examinations in a diagnostic CT environment. Current innovation in computed tomography (CT) is focused on radiomics, patient-specific radiation dose calculation, and image quality improvement using iterative reconstruction, all of which require specific knowledge of tissue and organ systems within a CT image. The purpose of this study was to develop a fully automated Random Forest classifier algorithm for segmentation of neck-chest-abdomen-pelvis CT examinations based on pediatric and adult CT protocols. Seven materials were classified: background, lung/internal air or gas, fat, muscle, solid organ parenchyma, blood/contrast enhanced fluid, and bone tissue using Matlab and the TWS plugin of FIJI. The following classifier feature filters of TWS were investigated: minimum, maximum, mean, and variance evaluated over a voxel radius of 2 n , (n from 0 to 4), along with noise reduction and edge preserving filters: Gaussian, bilateral, Kuwahara, and anisotropic diffusion. The Random Forest algorithm used 200 trees with 2 features randomly selected per node. The optimized auto-segmentation algorithm resulted in 16 image features including features derived from maximum, mean, variance Gaussian and Kuwahara filters. Dice similarity coefficient (DSC) calculations between manually segmented and Random Forest algorithm segmented images from 21 patient image sections, were analyzed. The automated algorithm produced segmentation of seven material classes with a median DSC of 0.86  ±  0.03 for pediatric patient protocols, and 0.85  ±  0.04 for adult patient protocols. Additionally, 100 randomly selected patient examinations were segmented and analyzed, and a mean sensitivity of 0.91 (range: 0.82-0.98), specificity of 0.89 (range: 0.70-0.98), and accuracy of 0.90 (range: 0.76-0.98) were demonstrated. In this study, we demonstrate that this fully automated segmentation tool was able to produce fast and accurate segmentation of the neck and trunk of the body over a wide range of patient habitus and scan parameters.

Investigator Ratings of ADHD Symptoms during a Randomized, Placebo-Controlled Trial of Atomoxetine: A Comparison of Parents and Teachers as Informants

ERIC Educational Resources Information Center

Bohnstedt, Bradley N.; Kronenberger, William G.; Dunn, David W.; Giauque, Ann L.; Wood, Elisabeth A.; Rembusch, Mary E.; Lafata, Deborah

2005-01-01

This study compared investigator ratings of ADHD symptoms based on interviews with parents and teachers during a doubleblind, placebo-controlled study of atomoxetine. Investigators completed the ADHD Rating Scale: Investigator (ADHDRS-I) based on separate semistructured interviews with the primary caretaker and teacher of the participant.…

Peer Inclusion in Interventions for Children with ADHD: A Systematic Review and Meta-Analysis

PubMed Central

Vilaysack, Brandon; Doma, Kenji; Wilkes-Gillan, Sarah; Speyer, Renée

2018-01-01

Objective To assess the effectiveness of peer inclusion in interventions to improve the social functioning of children with ADHD. Methods We searched four electronic databases for randomized controlled trials and controlled quasi-experimental studies that investigated peer inclusion interventions alone or combined with pharmacological treatment. Data were collected from the included studies and methodologically assessed. Meta-analyses were conducted using a random-effects model. Results Seventeen studies met eligibility criteria. Studies investigated interventions consisting of peer involvement and peer proximity; no study included peer mediation. Most included studies had an unclear or high risk of bias regarding inadequate reporting of randomization, blinding, and control for confounders. Meta-analyses indicated improvements in pre-post measures of social functioning for participants in peer-inclusive treatment groups. Peer inclusion was advantageous compared to treatment as usual. The benefits of peer inclusion over other therapies or medication only could not be determined. Using parents as raters for outcome measurement significantly mediated the intervention effect. Conclusions The evidence to support or contest the efficacy of peer inclusion interventions for children with ADHD is lacking. Future studies need to reduce risks of bias, use appropriate sample sizes, and provide detailed results to investigate the efficacy of peer inclusion interventions for children with ADHD. PMID:29744363

WWC Review of the Report "Evaluation of the College Possible Program: Results from a Randomized Controlled Trial." What Works Clearinghouse Single Study Review

ERIC Educational Resources Information Center

What Works Clearinghouse, 2014

2014-01-01

The 2013 study, "Evaluation of the College Possible Program: Results From a Randomized Controlled Trial", investigated the effect of the "College Possible" program, which is designed to serve low-income high school students by providing SAT/ACT test preparation, financial aid consulting, and college admissions guidance in an…

Attitude and Motivation as Predictors of Academic Achievement of Students in Clothing and Textiles

ERIC Educational Resources Information Center

Uwameiye, B. E.; Osho, L. E.

2011-01-01

This study investigated attitude and motivation as predictors of academic achievement of students in clothing and textiles. Three colleges of education in Edo and Delta States were randomly selected for use in this study. From each school, 40 students were selected from Year III using simple random technique yielding a total of 240 students. The…

Complications of Lumbar Artificial Disc Replacement Compared to Fusion: Results From the Prospective, Randomized, Multicenter US Food and Drug Administration Investigational Device Exemption Study of the Charité Artificial Disc

PubMed Central

Majd, Mohammed E.; Isaza, Jorge E.; Blumenthal, Scott L.; McAfee, Paul C.; Guyer, Richard D.; Hochschuler, Stephen H.; Geisler, Fred H.; Garcia, Rolando; Regan, John J.

2007-01-01

Background Previous reports of lumbar total disc replacement (TDR) have described significant complications. The US Food and Drug Administration (FDA) investigational device exemption (IDE) study of the Charité artificial disc represents the first level I data comparison of TDR to fusion. Methods In the prospective, randomized, multicenter IDE study, patients were randomized in a 2:1 ratio, with 205 patients in the Charité group and 99 patients in the control group (anterior lumbar interbody fusion [ALIF] with BAK cages). Inclusion criteria included confirmed single-level degenerative disc disease at L4-5 or L5-S1 and failure of nonoperative treatment for at least 6 months. Complications were reported throughout the study. Results The rate of approach-related complications was 9.8% in the investigational group and 10.1% in the control group. The rate of major neurological complications was similar between the 2 groups (investigational = 4.4%, control = 4.0%). There was a higher rate of superficial wound infection in the investigational group but no deep wound infections in either group. Pseudarthrosis occurred in 9.1% of control group patients. The rate of subsidence in the investigational group was 3.4%. The reoperation rate was 5.4% in the investigational group and 9.1% in the control group. Conclusions The incidence of perioperative and postoperative complications for lumbar TDR was similar to that of ALIF. Vigilance is necessary with respect to patient indications, training, and correct surgical technique to maintain TDR complications at the levels experienced in the IDE study. PMID:25802575

Subject-driven titration of biphasic insulin aspart 30 twice daily is non-inferior to investigator-driven titration in Chinese patients with type 2 diabetes inadequately controlled with premixed human insulin: A randomized, open-label, parallel-group, multicenter trial.

PubMed

Yang, Wenying; Zhu, Lvyun; Meng, Bangzhu; Liu, Yu; Wang, Wenhui; Ye, Shandong; Sun, Li; Miao, Heng; Guo, Lian; Wang, Zhanjian; Lv, Xiaofeng; Li, Quanmin; Ji, Qiuhe; Zhao, Weigang; Yang, Gangyi

2016-01-01

The present study was to compare the efficacy and safety of subject-driven and investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) twice daily (BID). In this 20-week, randomized, open-label, two-group parallel, multicenter trial, Chinese patients with type 2 diabetes inadequately controlled by premixed/self-mixed human insulin were randomized 1:1 to subject-driven or investigator-driven titration of BIAsp 30 BID, in combination with metformin and/or α-glucosidase inhibitors. Dose adjustment was decided by patients in the subject-driven group after training, and by investigators in the investigator-driven group. Eligible adults (n = 344) were randomized in the study. The estimated glycated hemoglobin (HbA1c) reduction was 14.5 mmol/mol (1.33%) in the subject-driven group and 14.3 mmol/mol (1.31%) in the investigator-driven group. Non-inferiority of subject-titration vs investigator-titration in reducing HbA1c was confirmed, with estimated treatment difference -0.26 mmol/mol (95% confidence interval -2.05, 1.53) (-0.02%, 95% confidence interval -0.19, 0.14). Fasting plasma glucose, postprandial glucose increment and self-measured plasma glucose were improved in both groups without statistically significant differences. One severe hypoglycemic event was experienced by one subject in each group. A similar rate of nocturnal hypoglycemia (events/patient-year) was reported in the subject-driven (1.10) and investigator-driven (1.32) groups. There were 64.5 and 58.1% patients achieving HbA1c <53.0 mmol/mol (7.0%), and 51.2 and 45.9% patients achieving the HbA1c target without confirmed hypoglycemia throughout the trial in the subject-driven and investigator-driven groups, respectively. Subject-titration of BIAsp 30 BID was as efficacious and well-tolerated as investigator-titration. The present study supported patients to self-titrate BIAsp 30 BID under physicians' supervision.

Factors Associated With Time to Site Activation, Randomization, and Enrollment Performance in a Stroke Prevention Trial.

PubMed

Demaerschalk, Bart M; Brown, Robert D; Roubin, Gary S; Howard, Virginia J; Cesko, Eldina; Barrett, Kevin M; Longbottom, Mary E; Voeks, Jenifer H; Chaturvedi, Seemant; Brott, Thomas G; Lal, Brajesh K; Meschia, James F; Howard, George

2017-09-01

Multicenter clinical trials attempt to select sites that can move rapidly to randomization and enroll sufficient numbers of patients. However, there are few assessments of the success of site selection. In the CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials), we assess factors associated with the time between site selection and authorization to randomize, the time between authorization to randomize and the first randomization, and the average number of randomizations per site per month. Potential factors included characteristics of the site, specialty of the principal investigator, and site type. For 147 sites, the median time between site selection to authorization to randomize was 9.9 months (interquartile range, 7.7, 12.4), and factors associated with early site activation were not identified. The median time between authorization to randomize and a randomization was 4.6 months (interquartile range, 2.6, 10.5). Sites with authorization to randomize in only the carotid endarterectomy study were slower to randomize, and other factors examined were not significantly associated with time-to-randomization. The recruitment rate was 0.26 (95% confidence interval, 0.23-0.28) patients per site per month. By univariate analysis, factors associated with faster recruitment were authorization to randomize in both trials, principal investigator specialties of interventional radiology and cardiology, pre-trial reported performance >50 carotid angioplasty and stenting procedures per year, status in the top half of recruitment in the CREST trial, and classification as a private health facility. Participation in StrokeNet was associated with slower recruitment as compared with the non-StrokeNet sites. Overall, selection of sites with high enrollment rates will likely require customization to align the sites selected to the factor under study in the trial. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02089217. © 2017 American Heart Association, Inc.

Financial ties of principal investigators and randomized controlled trial outcomes: cross sectional study.

PubMed

Ahn, Rosa; Woodbridge, Alexandra; Abraham, Ann; Saba, Susan; Korenstein, Deborah; Madden, Erin; Boscardin, W John; Keyhani, Salomeh

2017-01-17

 To examine the association between the presence of individual principal investigators' financial ties to the manufacturer of the study drug and the trial's outcomes after accounting for source of research funding.  Cross sectional study of randomized controlled trials (RCTs).  Studies published in "core clinical" journals, as identified by Medline, between 1 January 2013 and 31 December 2013.  Random sample of RCTs focused on drug efficacy.  Association between financial ties of principal investigators and study outcome.  A total of 190 papers describing 195 studies met inclusion criteria. Financial ties between principal investigators and the pharmaceutical industry were present in 132 (67.7%) studies. Of 397 principal investigators, 231 (58%) had financial ties and 166 (42%) did not. Of all principal investigators, 156 (39%) reported advisor/consultancy payments, 81 (20%) reported speakers' fees, 81 (20%) reported unspecified financial ties, 52 (13%) reported honorariums, 52 (13%) reported employee relationships, 52 (13%) reported travel fees, 41 (10%) reported stock ownership, and 20 (5%) reported having a patent related to the study drug. The prevalence of financial ties of principal investigators was 76% (103/136) among positive studies and 49% (29/59) among negative studies. In unadjusted analyses, the presence of a financial tie was associated with a positive study outcome (odds ratio 3.23, 95% confidence interval 1.7 to 6.1). In the primary multivariate analysis, a financial tie was significantly associated with positive RCT outcome after adjustment for the study funding source (odds ratio 3.57 (1.7 to 7.7). The secondary analysis controlled for additional RCT characteristics such as study phase, sample size, country of first authors, specialty, trial registration, study design, type of analysis, comparator, and outcome measure. These characteristics did not appreciably affect the relation between financial ties and study outcomes (odds ratio 3.37, 1.4 to 7.9).  Financial ties of principal investigators were independently associated with positive clinical trial results. These findings may be suggestive of bias in the evidence base. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Object Recognition and Random Image Structure Evolution

ERIC Educational Resources Information Center

Sadr, Jvid; Sinha, Pawan

2004-01-01

We present a technique called Random Image Structure Evolution (RISE) for use in experimental investigations of high-level visual perception. Potential applications of RISE include the quantitative measurement of perceptual hysteresis and priming, the study of the neural substrates of object perception, and the assessment and detection of subtle…

What Does It Mean to Do Something Randomly?

ERIC Educational Resources Information Center

Liu, Yating; Enderson, Mary C.

2016-01-01

A mysterious conflict of solutions emerged when a group of tenth- and eleventh-grade students were studying a seemingly ordinary problem on combination and probability. By investigating the mysterious "conflicts" caused by multiple randomization procedures, students will gain a deeper understanding of what it means to perform a task…

The treatment of medial tibial stress syndrome in athletes; a randomized clinical trial

PubMed Central

2012-01-01

Background The only three randomized trials on the treatment of MTSS were all performed in military populations. The treatment options investigated in this study were not previously examined in athletes. This study investigated if functional outcome of three common treatment options for medial tibial stress syndrome (MTSS) in athletes in a non-military setting was the same. Methods The study design was randomized and multi-centered. Physical therapists and sports physicians referred athletes with MTSS to the hospital for inclusion. 81 athletes were assessed for eligibility of which 74 athletes were included and randomized to three treatment groups. Group one performed a graded running program, group two performed a graded running program with additional stretching and strengthening exercises for the calves, while group three performed a graded running program with an additional sports compression stocking. The primary outcome measure was: time to complete a running program (able to run 18 minutes with high intensity) and secondary outcome was: general satisfaction with treatment. Results 74 Athletes were randomized and included of which 14 did not complete the study due a lack of progress (18.9%). The data was analyzed on an intention-to-treat basis. Time to complete a running program and general satisfaction with the treatment were not significantly different between the three treatment groups. Conclusion This was the first randomized trial on the treatment of MTSS in athletes in a non-military setting. No differences were found between the groups for the time to complete a running program. Trial registration CCMO; NL23471.098.08 PMID:22464032

Estimates of Intraclass Correlation for Variables Related to Behavioral HIV/STD Prevention in a Predominantly African American and Hispanic Sample of Young Women

ERIC Educational Resources Information Center

Pals, Sherri L.; Beaty, Brenda L.; Posner, Samuel F.; Bull, Sheana S.

2009-01-01

Studies designed to evaluate HIV and STD prevention interventions often involve random assignment of groups such as neighborhoods or communities to study conditions (e.g., to intervention or control). Investigators who design group-randomized trials (GRTs) must take the expected intraclass correlation coefficient (ICC) into account in sample size…

Testing the Storm et al. (2010) Meta-Analysis Using Bayesian and Frequentist Approaches: Reply to Rouder et al. (2013)

ERIC Educational Resources Information Center

Storm, Lance; Tressoldi, Patrizio E.; Utts, Jessica

2013-01-01

Rouder, Morey, and Province (2013) stated that (a) the evidence-based case for psi in Storm, Tressoldi, and Di Risio's (2010) meta-analysis is supported only by a number of studies that used manual randomization, and (b) when these studies are excluded so that only investigations using automatic randomization are evaluated (and some additional…

The feasibility and acceptability of conducting a trial of specialist medical care and the Lightning Process in children with chronic fatigue syndrome: feasibility randomized controlled trial (SMILE study)

PubMed Central

2013-01-01

Background Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is relatively common in children with limited evidence for treatment. The Phil Parker Lightning Process (LP) is a trademarked intervention, which >250 children use annually. There are no reported studies investigating the effectiveness or possible side effects of LP. Methods The trial population was drawn from the Bath and Bristol NHS specialist paediatric CFS or ME service. The study was designed as a pilot randomized trial with children (aged 12 to 18 years) comparing specialist medical care with specialist medical care plus the Lightning Process. Integrated qualitative methodology was used to explore the feasibility and acceptability of the recruitment, randomization and interventions. Results A total of 56 children were recruited from 156 eligible children (1 October 2010 to 16 June 2012). Recruitment, randomization and both interventions were feasible and acceptable. Participants suggested changes to improve feasibility and acceptability and we incorporated the following in the trial protocol: stopped collecting 6-week outcomes; introduced a second reminder letter; used phone calls to collect primary outcomes from nonresponders; informed participants about different approaches of each intervention and changed our recommendation for the primary outcome for the full study from school attendance to disability (SF-36 physical function subscale) and fatigue (Chalder Fatigue Scale). Conclusions Conducting randomized controlled trials (RCTs) to investigate an alternative treatment such as LP is feasible and acceptable for children with CFS or ME. Feasibility studies that incorporate qualitative methodology enable changes to be made to trial protocols to improve acceptability to participants. This is likely to improve recruitment rate and trial retention. Trial registration Feasibility study first randomization: 29 September 2010. Trial registration: Current Controlled Trials ISRCTN81456207 (31 July 2012). Full trial first randomization: 19 September 2012. PMID:24304689

Tunable random lasing behavior in plasmonic nanostructures

NASA Astrophysics Data System (ADS)

Yadav, Ashish; Zhong, Liubiao; Sun, Jun; Jiang, Lin; Cheng, Gary J.; Chi, Lifeng

2017-01-01

Random lasing is desired in plasmonics nanostructures through surface plasmon amplification. In this study, tunable random lasing behavior was observed in dye molecules attached with Au nanorods (NRs), Au nanoparticles (NPs) and Au@Ag nanorods (NRs) respectively. Our experimental investigations showed that all nanostructures i.e., Au@AgNRs, AuNRs & AuNPs have intensive tunable spectral effects. The random lasing has been observed at excitation wavelength 532 nm and varying pump powers. The best random lasing properties were noticed in Au@AgNRs structure, which exhibits broad absorption spectrum, sufficiently overlapping with that of dye Rhodamine B (RhB). Au@AgNRs significantly enhance the tunable spectral behavior through localized electromagnetic field and scattering. The random lasing in Au@AgNRs provides an efficient coherent feedback for random lasers.

Adjunctive use of a facial moisturizer SPF 30 containing ceramide precursor improves tolerability of topical tretinoin 0.05%: a randomized, investigator-blinded, split-face study.

PubMed

Schorr, Ethlynn S; Sidou, Farzi; Kerrouche, Nabil

2012-09-01

To assess the benefit of adjunctive use of a SPF 30 moisturizing lotion in reducing local side effects associated with atopical tretinoin cream. This was a randomized, investigator/evaluator-blinded, split-face comparison in subjects with healthy skin. Subjects applied tretinoin cream 0.05% once daily to the whole face and Cetaphil 174; Dermacontrol Moisturizer (CDM) once daily to one side of the face based on randomization. Tolerability, perference and skin hydration were evaluated at each week, and a cosmetic acceptability questionnaire regarding CDM was completed at the end of the study. The majority (about 83% to 86%) of subjects experienced skin irritations on both sides of their face, though predominantly mild for the CDM + tretinoin treated side. Tolerability preferences favored the CDM+tretinoin sides. Adjunctive use of CDM with a topical tretinoin cream improves tolerance of the treatment.

Financial ties of principal investigators and randomized controlled trial outcomes: cross sectional study

PubMed Central

Ahn, Rosa; Woodbridge, Alexandra; Abraham, Ann; Saba, Susan; Korenstein, Deborah; Madden, Erin; Boscardin, W John

2017-01-01

Objective To examine the association between the presence of individual principal investigators’ financial ties to the manufacturer of the study drug and the trial’s outcomes after accounting for source of research funding. Design Cross sectional study of randomized controlled trials (RCTs). Setting Studies published in “core clinical” journals, as identified by Medline, between 1 January 2013 and 31 December 2013. Participants Random sample of RCTs focused on drug efficacy. Main outcome measure Association between financial ties of principal investigators and study outcome. Results A total of 190 papers describing 195 studies met inclusion criteria. Financial ties between principal investigators and the pharmaceutical industry were present in 132 (67.7%) studies. Of 397 principal investigators, 231 (58%) had financial ties and 166 (42%) did not. Of all principal investigators, 156 (39%) reported advisor/consultancy payments, 81 (20%) reported speakers’ fees, 81 (20%) reported unspecified financial ties, 52 (13%) reported honorariums, 52 (13%) reported employee relationships, 52 (13%) reported travel fees, 41 (10%) reported stock ownership, and 20 (5%) reported having a patent related to the study drug. The prevalence of financial ties of principal investigators was 76% (103/136) among positive studies and 49% (29/59) among negative studies. In unadjusted analyses, the presence of a financial tie was associated with a positive study outcome (odds ratio 3.23, 95% confidence interval 1.7 to 6.1). In the primary multivariate analysis, a financial tie was significantly associated with positive RCT outcome after adjustment for the study funding source (odds ratio 3.57 (1.7 to 7.7). The secondary analysis controlled for additional RCT characteristics such as study phase, sample size, country of first authors, specialty, trial registration, study design, type of analysis, comparator, and outcome measure. These characteristics did not appreciably affect the relation between financial ties and study outcomes (odds ratio 3.37, 1.4 to 7.9). Conclusions Financial ties of principal investigators were independently associated with positive clinical trial results. These findings may be suggestive of bias in the evidence base. PMID:28096109

Effects of Emergent Literacy Interventions for Preschoolers with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Hudson, Roxanne F.; Sanders, Elizabeth A.; Greenway, Rosanne; Xie, Sharon; Smith, Maya; Gasamis, Colin; Martini, Jay; Schwartz, Ilene; Hackett, Jacob

2017-01-01

Combining data from a series of three planned consecutive randomized controlled trials, the present study investigates two literacy interventions for preschool children with autism spectrum disorder. For the first cohort, children were randomized to interactive book reading (IBR; treatment) or business as usual (BAU; control); in Cohort 2,…

Random Assignment and Informed Consent: A Case Study of Multiple Perspectives

ERIC Educational Resources Information Center

Walker, Robert; Hoggart, Lesley; Hamilton, Gayle

2008-01-01

Although random assignment is generally the preferred methodology in impact evaluations, it raises numerous ethical concerns, some of which are addressed by securing participants' informed consent. However, there has been little investigation of how consent is obtained in social experiments and the amount of information that can be conveyed--and…

Occupational Therapy Home Program for Children with Intellectual Disabilities: A Randomized, Controlled Trial

ERIC Educational Resources Information Center

Wuang, Yee-Pay; Ho, Guang-Sheng; Su, Chwen-Yng

2013-01-01

This study aimed to investigate the effectiveness of a proposed occupational therapy home program (OTHP) for children with intellectual disabilities (ID). Children with ID were randomly and equally assigned to OTHP or to no OTHP groups. The primary outcome measures were Canadian Occupational Performance, Bruininks-Oseretsky Test of Motor…

Randomized Controlled Trial of Video Self-Modeling Following Speech Restructuring Treatment for Stuttering

ERIC Educational Resources Information Center

Cream, Angela; O'Brian, Sue; Jones, Mark; Block, Susan; Harrison, Elisabeth; Lincoln, Michelle; Hewat, Sally; Packman, Ann; Menzies, Ross; Onslow, Mark

2010-01-01

Purpose: In this study, the authors investigated the efficacy of video self-modeling (VSM) following speech restructuring treatment to improve the maintenance of treatment effects. Method: The design was an open-plan, parallel-group, randomized controlled trial. Participants were 89 adults and adolescents who undertook intensive speech…

Youth-Nominated Support Team for Suicidal Adolescents (Version 1): A Randomized Controlled Trial

ERIC Educational Resources Information Center

King, Cheryl A.; Kramer, Anne; Preuss, Lesli; Kerr, David C. R.; Weisse, Lois; Venkataraman, Sanjeev

2006-01-01

In this study, the authors investigated the efficacy of the Youth-Nominated Support Team-Version 1 (YST-1), a psychoeducational social network intervention, with 289 suicidal, psychiatrically hospitalized adolescents (197 girls, 92 boys). Adolescents were randomly assigned to treatment-as-usual plus YST-1 or treatment-as-usual only. Assessments…

A Randomized Controlled Design Investigating the Effects of Classroom-Based Physical Activity on Children's Fluid Intelligence and Achievement

ERIC Educational Resources Information Center

Fedewa, Alicia L.; Ahn, Soyeon; Erwin, Heather; Davis, Matthew C.

2015-01-01

Existing literature shows promising effects of physical activity on children's cognitive outcomes. This study assessed via a randomized, controlled design whether additional curricular physical activity during the school day resulted in gains for children's fluid intelligence and standardized achievement outcomes. Participants were children…

Effects of an Early Numeracy Intervention on Struggling Kindergarteners' Mathematics Performance

ERIC Educational Resources Information Center

Bryant, Brian R.; Bryant, Diane Pedrotty; Roberts, Greg; Fall, Anna-Maria

2016-01-01

The purpose of this study was to investigate the effects of an early numeracy intervention delivered by kindergarten teachers to students identified as having mathematics difficulties. A multigroup growth-modeling-with-random-assignment-to-intervention-condition design was employed. Thirty-two teachers were randomly assigned to the treatment or…

Moderators of Theory-Based Interventions to Promote Physical Activity in 77 Randomized Controlled Trials

ERIC Educational Resources Information Center

Bernard, Paquito; Carayol, Marion; Gourlan, Mathieu; Boiché, Julie; Romain, Ahmed Jérôme; Bortolon, Catherine; Lareyre, Olivier; Ninot, Gregory

2017-01-01

A meta-analysis of randomized controlled trials (RCTs) has recently showed that theory-based interventions designed to promote physical activity (PA) significantly increased PA behavior. The objective of the present study was to investigate the moderators of the efficacy of these theory-based interventions. Seventy-seven RCTs evaluating…

Random phase approximation and cluster mean field studies of hard core Bose Hubbard model

NASA Astrophysics Data System (ADS)

Alavani, Bhargav K.; Gaude, Pallavi P.; Pai, Ramesh V.

2018-04-01

We investigate zero temperature and finite temperature properties of the Bose Hubbard Model in the hard core limit using Random Phase Approximation (RPA) and Cluster Mean Field Theory (CMFT). We show that our RPA calculations are able to capture quantum and thermal fluctuations significantly better than CMFT.

Moving from Efficacy to Effectiveness in Cognitive Behavioral Therapy for Psychosis: A Randomized Clinical Practice Trial

ERIC Educational Resources Information Center

Lincoln, Tania M.; Ziegler, Michael; Mehl, Stephanie; Kesting, Marie-Luise; Lullmann, Eva; Westermann, Stefan; Rief, Winfried

2012-01-01

Objective: Randomized controlled trials have attested the efficacy of cognitive behavioral therapy (CBT) in reducing psychotic symptoms. Now, studies are needed to investigate its effectiveness in routine clinical practice settings. Method: Eighty patients with schizophrenia spectrum disorders who were seeking outpatient treatment were randomized…

The Development of an Internet-Based Treatment for Problem Gamblers and Concerned Significant Others: A Pilot Randomized Controlled Trial.

PubMed

Nilsson, Anders; Magnusson, Kristoffer; Carlbring, Per; Andersson, Gerhard; Gumpert, Clara Hellner

2018-06-01

Problem gambling creates significant harm for the gambler and for concerned significant others (CSOs). While several studies have investigated the effects of individual cognitive behavioral therapy (CBT) for problem gambling, less is known about the effects of involving CSOs in treatment. Behavioral couples therapy (BCT) has shown promising results when working with substance use disorders by involving both the user and a CSO. This pilot study investigated BCT for problem gambling, as well as the feasibility of performing a larger scale randomized controlled trial. 36 participants, 18 gamblers and 18 CSOs, were randomized to either BCT or individual CBT for the gambler. Both interventions were Internet-delivered self-help interventions with therapist support. Both groups of gamblers improved on all outcome measures, but there were no differences between the groups. The CSOs in the BCT group lowered their scores on anxiety and depression more than the CSOs of those randomized to the individual CBT group did. The implications of the results and the feasibility of the trial are discussed.

Memory consolidation and contextual interference effects with computer games.

PubMed

Shewokis, Patricia A

2003-10-01

Some investigators of the contextual interference effect contend that there is a direct relation between the amount of practice and the contextual interference effect based on the prediction that the improvement in learning tasks in a random practice schedule, compared to a blocked practice schedule, increases in magnitude as the amount of practice during acquisition on the tasks increases. Research using computer games in contextual interference studies has yielded a large effect (f = .50) with a random practice schedule advantage during transfer. These investigations had a total of 36 and 72 acquisition trials, respectively. The present study tested this prediction by having 72 college students, who were randomly assigned to a blocked or random practice schedule, practice 102 trials of three computer-game tasks across three days. After a 24-hr. interval, 6 retention and 5 transfer trials were performed. Dependent variables were time to complete an event in seconds and number of errors. No significant differences were found for retention and transfer. These results are discussed in terms of how the amount of practice, task-related factors, and memory consolidation mediate the contextual interference effect.

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.

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

Random matrices and condensation into multiple states

NASA Astrophysics Data System (ADS)

Sadeghi, Sina; Engel, Andreas

2018-03-01

In the present work, we employ methods from statistical mechanics of disordered systems to investigate static properties of condensation into multiple states in a general framework. We aim at showing how typical properties of random interaction matrices play a vital role in manifesting the statistics of condensate states. In particular, an analytical expression for the fraction of condensate states in the thermodynamic limit is provided that confirms the result of the mean number of coexisting species in a random tournament game. We also study the interplay between the condensation problem and zero-sum games with correlated random payoff matrices.

Practices that minimize trauma to the genital tract in childbirth: a systematic review of the literature.

PubMed

Renfrew, M J; Hannah, W; Albers, L; Floyd, E

1998-09-01

Trauma to the genital tract commonly occurs at birth, and can cause short- and long-term morbidity. Clinical measures to reduce its occurrence have not been fully identified. A systematic review of the English language literature was conducted to describe the current state of knowledge on reduction of genital tract trauma before planning a large randomized controlled trial of ways to prevent such trauma. Randomized trials and other published reports were identified from relevant databases and hand searches. Studies were reviewed and assessed using a structured format. A total of 77 papers and chapters were identified and placed into 5 categories after critical review: 25 randomized trials, 4 meta-analyses, 4 prospective studies, 36 retrospective studies, and 8 descriptions of practice from textbooks. The available evidence is conclusive in favor of restricted use of episiotomy. The contribution of maternal characteristics and attitudes to intact perineum has not been investigated. Several other topics warrant further study, including maternal position, style of pushing, and antenatal perineal massage. Strong opinions and sparse data exist regarding the role of hand maneuvers by the birth attendant for perineal management and birth of the baby. This became the topic of the planned randomized controlled trial, which was completed; results will be published soon. The case for restricting the use of episiotomy is conclusive. Several other clinical factors warrant investigation, including the role of hand maneuvers by the birth attendant in preventing birth trauma. A large randomized controlled trial will report on this topic.

Factors Predicting Compliance to Ecological Momentary Assessment Among Adolescent Smokers

PubMed Central

2014-01-01

Introduction: Ecological momentary assessments (EMAs) are increasingly used in smoking research to understand contextual and individual differences related to smoking and changes in smoking. To date, there has been little detailed research into the predictors of EMA compliance. However, patterns or predictors of compliance may affect key relationships under investigation and introduce sources of bias in results. The purpose of this study was to investigate predictors of compliance to random prompts among a sample of adolescents who had ever smoked. Methods: Data for this study were drawn from a sample of 461 adolescents (9th and 10th graders at baseline) participating in a longitudinal study of smoking escalation. We examined 2 outcomes: subject-level EMA compliance (overall rate of compliance over a week-long EMA wave), and in-the-moment prompt-level compliance to the most proximal random prompt. We investigated several covariates including gender, race, smoking rate, alcohol use, psychological symptomatology, home composition, mood, social context, time in study, inter-prompt interval, and location. Results: At the overall subject level, higher mean negative affect, smoking rate, alcohol use, and male gender predicted lower compliance with random EMA prompts. At the prompt level, after controlling for significant subject-level predictors of compliance, increased positive affect, being outside of the home, and longer inter-prompt interval predicted lower momentary compliance. Conclusions: This study identifies several factors associated with overall and momentary EMA compliance among a sample of adolescents participating in a longitudinal study of smoking. We also propose a conceptual framework for investigating the contextual and momentary predictors of compliance within EMA studies. PMID:24097816

Detecting Random, Partially Random, and Nonrandom Minnesota Multiphasic Personality Inventory-2 Protocols

ERIC Educational Resources Information Center

Pinsoneault, Terry B.

2007-01-01

The ability of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; J. N. Butcher et al., 2001) validity scales to detect random, partially random, and nonrandom MMPI-2 protocols was investigated. Investigations included the Variable Response Inconsistency scale (VRIN), F, several potentially useful new F and VRIN subscales, and F-sub(b) - F…

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.

Fine structure of transient waves in a random medium: The correlation and spectral density functions

NASA Technical Reports Server (NTRS)

Wenzel, Alan R.

1994-01-01

This is essentially a progress report on a theoretical investigation of the propagation of transient waves in a random medium. The emphasis in this study is on applications to sonic-boom propagation, particularly as regards the effect of atmospheric turbulence on the sonic-boom waveform. The analysis is general, however, and is applicable to other types of waves besides sonic-boom waves. The phenomenon of primary concern in this investigation is the fine structure of the wave. A figure is used to illustrate what is meant by finestructure.

Synchronizability of random rectangular graphs

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

Estrada, Ernesto, E-mail: ernesto.estrada@strath.ac.uk; Chen, Guanrong

2015-08-15

Random rectangular graphs (RRGs) represent a generalization of the random geometric graphs in which the nodes are embedded into hyperrectangles instead of on hypercubes. The synchronizability of RRG model is studied. Both upper and lower bounds of the eigenratio of the network Laplacian matrix are determined analytically. It is proven that as the rectangular network is more elongated, the network becomes harder to synchronize. The synchronization processing behavior of a RRG network of chaotic Lorenz system nodes is numerically investigated, showing complete consistence with the theoretical results.

Block randomization versus complete randomization of human perception stimuli: is there a difference?

NASA Astrophysics Data System (ADS)

Moyer, Steve; Uhl, Elizabeth R.

2015-05-01

For more than 50 years, the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) has been studying and modeling the human visual discrimination process as it pertains to military imaging systems. In order to develop sensor performance models, human observers are trained to expert levels in the identification of military vehicles. From 1998 until 2006, the experimental stimuli were block randomized, meaning that stimuli with similar difficulty levels (for example, in terms of distance from target, blur, noise, etc.) were presented together in blocks of approximately 24 images but the order of images within the block was random. Starting in 2006, complete randomization came into vogue, meaning that difficulty could change image to image. It was thought that this would provide a more statistically robust result. In this study we investigated the impact of the two types of randomization on performance in two groups of observers matched for skill to create equivalent groups. It is hypothesized that Soldiers in the Complete Randomized condition will have to shift their decision criterion more frequently than Soldiers in the Block Randomization group and this shifting is expected to impede performance so that Soldiers in the Block Randomized group perform better.

Obstacles of Teaching Mathematics Faced by the Class Teachers in Jordan

ERIC Educational Resources Information Center

Nejem, Khamis Mousa; Muhanna, Waffa

2013-01-01

The purpose of the study is to investigate the obstacles of teaching mathematics faced by the class teachers in Jordan. To achieve this purpose a study sample of 192 male and female class teachers was selected randomly from government schools. The instrument of the study was a questionnaire used to investigate the obstacles of mathematics…

College Students' Study Strategies as a Function of Testing: An Investigation into Metacognitive Self-Regulation

ERIC Educational Resources Information Center

Ross, Margaret E.; Green, Samuel B.; Salisbury-Glennon, Jill D.; Tollefson, Nona

2006-01-01

We conducted the present study to investigate whether college students adjust their study strategies to meet the cognitive demands of testing, a metacognitive self-regulatory skill. Participants were randomly assigned to one of the two testing conditions. In one condition we told participants to study for a test that required deep-level cognitive…

Testing the Efficacy of a Kindergarten Mathematics Intervention by Small Group Size

ERIC Educational Resources Information Center

Clarke, Ben; Doabler, Christian T.; Kosty, Derek; Kurtz Nelson, Evangeline; Smolkowski, Keith; Fien, Hank; Turtura, Jessica

2017-01-01

This study used a randomized controlled trial design to investigate the ROOTS curriculum, a 50-lesson kindergarten mathematics intervention. Ten ROOTS-eligible students per classroom (n = 60) were randomly assigned to one of three conditions: a ROOTS five-student group, a ROOTS two-student group, and a no-treatment control group. Two primary…

Modeling the Stress Complexities of Teaching and Learning of School Physics in Nigeria

ERIC Educational Resources Information Center

Emetere, Moses E.

2014-01-01

This study was designed to investigate the validity of the stress complexity model (SCM) to teaching and learning of school physics in Abuja municipal area council of Abuja, North. About two hundred students were randomly selected by a simple random sampling technique from some schools within the Abuja municipal area council. A survey research…

Dynamic probability of reinforcement for cooperation: Random game termination in the centipede game.

PubMed

Krockow, Eva M; Colman, Andrew M; Pulford, Briony D

2018-03-01

Experimental games have previously been used to study principles of human interaction. Many such games are characterized by iterated or repeated designs that model dynamic relationships, including reciprocal cooperation. To enable the study of infinite game repetitions and to avoid endgame effects of lower cooperation toward the final game round, investigators have introduced random termination rules. This study extends previous research that has focused narrowly on repeated Prisoner's Dilemma games by conducting a controlled experiment of two-player, random termination Centipede games involving probabilistic reinforcement and characterized by the longest decision sequences reported in the empirical literature to date (24 decision nodes). Specifically, we assessed mean exit points and cooperation rates, and compared the effects of four different termination rules: no random game termination, random game termination with constant termination probability, random game termination with increasing termination probability, and random game termination with decreasing termination probability. We found that although mean exit points were lower for games with shorter expected game lengths, the subjects' cooperativeness was significantly reduced only in the most extreme condition with decreasing computer termination probability and an expected game length of two decision nodes. © 2018 Society for the Experimental Analysis of Behavior.

Coordination and Management of Multisite Complementary and Alternative Medicine (CAM) Therapies: Experience from a Multisite Reflexology Intervention Trial

PubMed Central

Rahbar, Mohammad H.; Wyatt, Gwen; Sikorskii, Alla; Victorson, David; Ardjomand-Hessabi, Manouchehr

2011-01-01

Background Multisite randomized clinical trials allow for increased research collaboration among investigators and expedite data collection efforts. As a result, government funding agencies typically look favorably upon this approach. As the field of complementary and alternative medicine (CAM) continues to evolve, so do increased calls for the use of more rigorous study design and trial methodologies, which can present challenges for investigators. Purpose To describe the processes involved in the coordination and management of a multisite randomized clinical trial of a CAM intervention. Methods Key aspects related to the coordination and management of a multisite CAM randomized clinical trial are presented, including organizational and site selection considerations, recruitment concerns and issues related to data collection and randomization to treatment groups. Management and monitoring of data, as well as quality assurance procedures are described. Finally, a real world perspective is shared from a recently conducted multisite randomized clinical trial of reflexology for women diagnosed with advanced breast cancer. Results The use of multiple sites in the conduct of CAM-based randomized clinical trials can provide an efficient, collaborative and robust approach to study coordination and data collection that maximizes efficiency and ensures the quality of results. Conclusions Multisite randomized clinical trial designs can offer the field of CAM research a more standardized and efficient approach to examine the effectiveness of novel therapies and treatments. Special attention must be given to intervention fidelity, consistent data collection and ensuring data quality. Assessment and reporting of quantitative indicators of data quality should be required. PMID:21664296

An instrumental variable random-coefficients model for binary outcomes

PubMed Central

Chesher, Andrew; Rosen, Adam M

2014-01-01

In this paper, we study a random-coefficients model for a binary outcome. We allow for the possibility that some or even all of the explanatory variables are arbitrarily correlated with the random coefficients, thus permitting endogeneity. We assume the existence of observed instrumental variables Z that are jointly independent with the random coefficients, although we place no structure on the joint determination of the endogenous variable X and instruments Z, as would be required for a control function approach. The model fits within the spectrum of generalized instrumental variable models, and we thus apply identification results from our previous studies of such models to the present context, demonstrating their use. Specifically, we characterize the identified set for the distribution of random coefficients in the binary response model with endogeneity via a collection of conditional moment inequalities, and we investigate the structure of these sets by way of numerical illustration. PMID:25798048

Omega-3/Omega-6 Fatty Acids for Attention Deficit Hyperactivity Disorder: A Randomized Placebo-Controlled Trial in Children and Adolescents

ERIC Educational Resources Information Center

Johnson, Mats; Ostlund, Sven; Fransson, Gunnar; Kadesjo, Bjorn; Gillberg, Christopher

2009-01-01

Objective: The aim of the study was to assess omega 3/6 fatty acids (eye q) in attention deficit hyperactivity disorder (ADHD). Method: The study included a randomized, 3-month, omega 3/6 placebo-controlled, one-way crossover trial with 75 children and adolescents (8-18 years), followed by 3 months with omega 3/6 for all. Investigator-rated ADHD…

Testing the structure of earthquake networks from multivariate time series of successive main shocks in Greece

NASA Astrophysics Data System (ADS)

Chorozoglou, D.; Kugiumtzis, D.; Papadimitriou, E.

2018-06-01

The seismic hazard assessment in the area of Greece is attempted by studying the earthquake network structure, such as small-world and random. In this network, a node represents a seismic zone in the study area and a connection between two nodes is given by the correlation of the seismic activity of two zones. To investigate the network structure, and particularly the small-world property, the earthquake correlation network is compared with randomized ones. Simulations on multivariate time series of different length and number of variables show that for the construction of randomized networks the method randomizing the time series performs better than methods randomizing directly the original network connections. Based on the appropriate randomization method, the network approach is applied to time series of earthquakes that occurred between main shocks in the territory of Greece spanning the period 1999-2015. The characterization of networks on sliding time windows revealed that small-world structure emerges in the last time interval, shortly before the main shock.

Simvastatin as an Adjunct to Conventional Therapy of Non-infectious Uveitis: A Randomized, Open-Label Pilot Study.

PubMed

Shirinsky, Ivan V; Biryukova, Anastasia A; Shirinsky, Valery S

2017-12-01

Statins have been shown to reduce ocular inflammation in animal models of uveitis and to prevent development of uveitis in observational studies. There have been no experimental human studies evaluating statins' efficacy and safety in uveitis. In this study, we aimed to investigate efficacy and safety of simvastatin in patients with uveitis. For this single-center, open-label, randomized study, we enrolled patients with acute non-infectious uveitis. The patients were randomized to receive 40 mg simvastatin per day for 2 months in addition to conventional treatment or conventional treatment alone. The studied outcomes were the rate of steroid-sparing control of ocular inflammation, measures of ocular inflammation, intraocular pressure, and visual acuity. Fifty patients were enrolled in the study. Twenty-five patients were randomly assigned to receive simvastatin with conventional treatment and 25 to conventional treatment alone. Simvastatin was associated with significantly higher rates of steroid-sparing ocular inflammation control, decrease in anterior chamber inflammation, and improvement in visual acuity. The treatment was well tolerated, no serious adverse effects were observed. Our findings suggest that statins may have therapeutic potential in uveitis. These results need to be confirmed in double-blind, randomized, controlled studies.

Investigating Test Equating Methods in Small Samples through Various Factors

ERIC Educational Resources Information Center

Asiret, Semih; Sünbül, Seçil Ömür

2016-01-01

In this study, equating methods for random group design using small samples through factors such as sample size, difference in difficulty between forms, and guessing parameter was aimed for comparison. Moreover, which method gives better results under which conditions was also investigated. In this study, 5,000 dichotomous simulated data…

A Waitlist-Controlled Trial of Behavioral Parent Training for Fathers of Children with ADHD

ERIC Educational Resources Information Center

Fabiano, Gregory A.; Pelham, William E.; Cunningham, Charles E.; Yu, Jihnhee; Gangloff, Brian; Buck, Melina; Linke, Stuart; Gormley, Matthew; Gera, Shradha

2012-01-01

Fathers, in general, have been underrepresented in studies of parent training outcome for children with attention deficit hyperactivity disorder (ADHD), and the present study aimed to investigate the efficacy of a behavioral parent training program developed expressly for fathers. The present investigation randomly assigned 55 fathers of children…

Study Design Rigor in Animal-Experimental Research Published in Anesthesia Journals.

PubMed

Hoerauf, Janine M; Moss, Angela F; Fernandez-Bustamante, Ana; Bartels, Karsten

2018-01-01

Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals. PubMed was searched for animal-experimental studies published in 2005, 2010, and 2015 in primarily English-language anesthesia journals. A total of 1466 publications were graded on the performance of sample size estimation, randomization, and blinding. Cochran-Armitage test was used to assess linear trends over time for the primary outcome of whether or not a metric was reported. Interrater agreement for each of the 3 metrics (power, randomization, and blinding) was assessed using the weighted κ coefficient in a 10% random sample of articles rerated by a second investigator blinded to the ratings of the first investigator. A total of 1466 manuscripts were analyzed. Reporting for all 3 metrics of experimental design rigor increased over time (2005 to 2010 to 2015): for power analysis, from 5% (27/516), to 12% (59/485), to 17% (77/465); for randomization, from 41% (213/516), to 50% (243/485), to 54% (253/465); and for blinding, from 26% (135/516), to 38% (186/485), to 47% (217/465). The weighted κ coefficients and 98.3% confidence interval indicate almost perfect agreement between the 2 raters beyond that which occurs by chance alone (power, 0.93 [0.85, 1.0], randomization, 0.91 [0.85, 0.98], and blinding, 0.90 [0.84, 0.96]). Our hypothesis that reported metrics of rigor in animal-experimental studies in anesthesia journals have increased during the past decade was confirmed. More consistent reporting, or explicit justification for absence, of sample size calculations, blinding techniques, and randomization procedures could better enable readers to evaluate potential sources of bias in animal-experimental research manuscripts. Future studies should assess whether such steps lead to improved translation of animal-experimental anesthesia research into successful clinical trials.

Random complex dynamics and devil's coliseums

NASA Astrophysics Data System (ADS)

Sumi, Hiroki

2015-04-01

We investigate the random dynamics of polynomial maps on the Riemann sphere \\hat{\\Bbb{C}} and the dynamics of semigroups of polynomial maps on \\hat{\\Bbb{C}} . In particular, the dynamics of a semigroup G of polynomials whose planar postcritical set is bounded and the associated random dynamics are studied. In general, the Julia set of such a G may be disconnected. We show that if G is such a semigroup, then regarding the associated random dynamics, the chaos of the averaged system disappears in the C0 sense, and the function T∞ of probability of tending to ∞ \\in \\hat{\\Bbb{C}} is Hölder continuous on \\hat{\\Bbb{C}} and varies only on the Julia set of G. Moreover, the function T∞ has a kind of monotonicity. It turns out that T∞ is a complex analogue of the devil's staircase, and we call T∞ a ‘devil’s coliseum'. We investigate the details of T∞ when G is generated by two polynomials. In this case, T∞ varies precisely on the Julia set of G, which is a thin fractal set. Moreover, under this condition, we investigate the pointwise Hölder exponents of T∞.

Rationale and study design of PROVHILO - a worldwide multicenter randomized controlled trial on protective ventilation during general anesthesia for open abdominal surgery.

PubMed

Hemmes, Sabrine N T; Severgnini, Paolo; Jaber, Samir; Canet, Jaume; Wrigge, Hermann; Hiesmayr, Michael; Tschernko, Edda M; Hollmann, Markus W; Binnekade, Jan M; Hedenstierna, Göran; Putensen, Christian; de Abreu, Marcelo Gama; Pelosi, Paolo; Schultz, Marcus J

2011-05-06

Post-operative pulmonary complications add to the morbidity and mortality of surgical patients, in particular after general anesthesia >2 hours for abdominal surgery. Whether a protective mechanical ventilation strategy with higher levels of positive end-expiratory pressure (PEEP) and repeated recruitment maneuvers; the "open lung strategy", protects against post-operative pulmonary complications is uncertain. The present study aims at comparing a protective mechanical ventilation strategy with a conventional mechanical ventilation strategy during general anesthesia for abdominal non-laparoscopic surgery. The PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure ("PROVHILO") trial is a worldwide investigator-initiated multicenter randomized controlled two-arm study. Nine hundred patients scheduled for non-laparoscopic abdominal surgery at high or intermediate risk for post-operative pulmonary complications are randomized to mechanical ventilation with the level of PEEP at 12 cmH(2)O with recruitment maneuvers (the lung-protective strategy) or mechanical ventilation with the level of PEEP at maximum 2 cmH(2)O without recruitment maneuvers (the conventional strategy). The primary endpoint is any post-operative pulmonary complication. The PROVHILO trial is the first randomized controlled trial powered to investigate whether an open lung mechanical ventilation strategy in short-term mechanical ventilation prevents against postoperative pulmonary complications. ISRCTN: ISRCTN70332574.

Alcohol-Specific Parenting within a Cluster-Randomized Effectiveness Trial of a Swedish Primary Prevention Program

ERIC Educational Resources Information Center

Strandberg, Anna K.; Bodin, Maria C.

2011-01-01

Purpose: Within the framework of an ongoing cluster-randomized effectiveness trial of a parental prevention program, the aim of the present study is to investigate attitudes towards under-age drinking and use of program components, i.e. alcohol-specific parenting behaviors, in parents who did and did not take part in the programme.…

The YouthMood Project: A Cluster Randomized Controlled Trial of an Online Cognitive Behavioral Program with Adolescents

ERIC Educational Resources Information Center

Calear, Alison L.; Christensen, Helen; Mackinnon, Andrew; Griffiths, Kathleen M.; O'Kearney, Richard

2009-01-01

The aim in the current study was to investigate the effectiveness of an online, self-directed cognitive-behavioral therapy program (MoodGYM) in preventing and reducing the symptoms of anxiety and depression in an adolescent school-based population. A cluster randomized controlled trial was conducted with 30 schools (N = 1,477) from across…

Evaluation of a 2-Year Physical Activity and Healthy Eating Intervention in Middle School Children

ERIC Educational Resources Information Center

Haerens, Leen; Deforche, Benedicte; Maes, Lea; Cardon, Greet; Stevens, Veerle; De Bourdeaudhuij, Ilse

2006-01-01

The aim of the present study was to evaluate the effects of a middle school physical activity and healthy eating intervention, including an environmental and computer-tailored component, and to investigate the effects of parental involvement. A random sample of 15 schools with seventh and eight graders was randomly assigned to one of three…

Ice Hockey Players Using a Weighted Implement when Training on the Ice: A Randomized Control Trial

ERIC Educational Resources Information Center

Stark, Timothy W.; Tvoric, Bojan; Walker, Bruce; Noonan, Dom; Sibla, Janeene

2009-01-01

The purpose of this study was to investigate the potential for improving hockey players' performance using a weighted implement on the ice. Forty-eight players were tested using a grip strength dynamometer. They also were assessed on their abilities to stick-handle. The participants were randomly placed into a control or research group. The…

Evaluation of a Brief Parent Intervention Teaching Coping-Promoting Behavior for the Infant Immunization Context: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Bustos, Theona; Jaaniste, Tiina; Salmon, Karen; Champion, G. David

2008-01-01

This study was designed to investigate whether a brief intervention encouraging parental coping-promoting talk within the treatment room would have beneficial effects on infant pain responses to an immunization injection. Infant-parent dyads were recruited from a 6-month immunization clinic and randomized to an intervention group (n = 25) or…

The Effect of Herrmann Whole Brain Teaching Method on Students' Understanding of Simple Electric Circuits

ERIC Educational Resources Information Center

Bawaneh, Ali Khalid Ali; Nurulazam Md Zain, Ahmad; Salmiza, Saleh

2011-01-01

The purpose of this study was to investigate the effect of Herrmann Whole Brain Teaching Method over conventional teaching method on eight graders in their understanding of simple electric circuits in Jordan. Participants (N = 273 students; M = 139, F = 134) were randomly selected from Bani Kenanah region-North of Jordan and randomly assigned to…

Random preferences towards bioenergy environmental externalities: a case study of woody biomass based electricity in the Southern United States

Treesearch

Andres Susaeta; Pankaj Lal; Janaki Alavalapati; Evan Mercer

2011-01-01

This paper contrasts alternate methodological approaches of investigating public preferences, the random parameter logit (RPL) where tastes and preferences of respondents are assumed to be heterogeneous and the conditional logit (CL) approach where tastes and preferences remain fixed for individuals. We conducted a choice experiment to assess preferences for woody...

Modeling of Academic Achievement of Primary School Students in Ethiopia Using Bayesian Multilevel Approach

ERIC Educational Resources Information Center

Sebro, Negusse Yohannes; Goshu, Ayele Taye

2017-01-01

This study aims to explore Bayesian multilevel modeling to investigate variations of average academic achievement of grade eight school students. A sample of 636 students is randomly selected from 26 private and government schools by a two-stage stratified sampling design. Bayesian method is used to estimate the fixed and random effects. Input and…

Using a Random Dependent Group Contingency to Increase On-Task Behaviors of High School Students with High Incidence Disabilities

ERIC Educational Resources Information Center

Williamson, Brenda D.; Campbell-Whatley, Gloria D.; Lo, Ya-yu

2009-01-01

Group contingencies have the advantages of encouraging individual students to collectively feel responsible for appropriate and inappropriate classroom behaviors and have shown effectiveness in improving students' behavior. The purpose of this study was to investigate the effects of a random dependent group contingency on the on-task behaviors of…

Lessons learned from a practice-based, multi-site intervention study with nurse participants

PubMed Central

Friese, Christopher R.; Mendelsohn-Victor, Kari; Ginex, Pamela; McMahon, Carol M.; Fauer, Alex J.; McCullagh, Marjorie C.

2016-01-01

Purpose To identify challenges and solutions to the efficient conduct of a multi-site, practice-based randomized controlled trial to improve nurses’ adherence to personal protective equipment use in ambulatory oncology settings. Design The Drug Exposure Feedback and Education for Nurses’ Safety (DEFENS) study is a clustered, randomized, controlled trial. Participating sites are randomized to web-based feedback on hazardous drug exposures in the sites plus tailored messages to address barriers versus a control intervention of a web-based continuing education video. Approach The study principal investigator, the study coordinator, and two site leaders identified challenges to study implementation and potential solutions, plus potential methods to prevent logistical challenges in future studies. Findings Noteworthy challenges included variation in human subjects protection policies, grants and contracts budgeting, infrastructure for nursing-led research, and information technology variation. Successful strategies included scheduled web conferences, site-based study champions, site visits by the principal investigator, and centrally-based document preparation. Strategies to improve efficiency in future studies include early and continued engagement with contract personnel in sites, and proposed changes to the common rule concerning human subjects. The DEFENS study successfully recruited 393 nurses across 12 sites. To date, 369 have completed surveys and 174 nurses have viewed educational materials. Conclusions Multi-site studies of nursing personnel are rare and challenging to existing infrastructure. These barriers can be overcome with strong engagement and planning. Clinical Relevance Leadership engagement, onsite staff support, and continuous communication can facilitate successful recruitment to a workplace-based randomized, controlled behavioral trial. PMID:28098951

Enhancing Motion-In-Depth Perception of Random-Dot Stereograms.

PubMed

Zhang, Di; Nourrit, Vincent; De Bougrenet de la Tocnaye, Jean-Louis

2018-07-01

Random-dot stereograms have been widely used to explore the neural mechanisms underlying binocular vision. Although they are a powerful tool to stimulate motion-in-depth (MID) perception, published results report some difficulties in the capacity to perceive MID generated by random-dot stereograms. The purpose of this study was to investigate whether the performance of MID perception could be improved using an appropriate stimulus design. Sixteen inexperienced observers participated in the experiment. A training session was carried out to improve the accuracy of MID detection before the experiment. Four aspects of stimulus design were investigated: presence of a static reference, background texture, relative disparity, and stimulus contrast. Participants' performance in MID direction discrimination was recorded and compared to evaluate whether varying these factors helped MID perception. Results showed that only the presence of background texture had a significant effect on MID direction perception. This study provides suggestions for the design of 3D stimuli in order to facilitate MID perception.

Aging in the three-dimensional random-field Ising model

NASA Astrophysics Data System (ADS)

von Ohr, Sebastian; Manssen, Markus; Hartmann, Alexander K.

2017-07-01

We studied the nonequilibrium aging behavior of the random-field Ising model in three dimensions for various values of the disorder strength. This allowed us to investigate how the aging behavior changes across the ferromagnetic-paramagnetic phase transition. We investigated a large system size of N =2563 spins and up to 108 Monte Carlo sweeps. To reach these necessary long simulation times, we employed an implementation running on Intel Xeon Phi coprocessors, reaching single-spin-flip times as short as 6 ps. We measured typical correlation functions in space and time to extract a growing length scale and corresponding exponents.

Efficacy of early controlled motion of the ankle compared with no motion after non-operative treatment of an acute Achilles tendon rupture: study protocol for a randomized controlled trial.

PubMed

Barfod, Kristoffer Weisskirchner; Hansen, Maria Swennergren; Holmich, Per; Troelsen, Anders; Kristensen, Morten Tange

2016-11-29

Early controlled ankle motion is widely used in the non-operative treatment of acute Achilles tendon rupture, though its safety and efficacy have never been investigated in a randomized setup. The objectives of this study are to investigate if early controlled motion of the ankle affects functional and patient-reported outcomes. The study is performed as a blinded, randomized, controlled trial with patients allocated in a 1:1 ratio to one of two parallel groups. Patients aged from 18 to 70 years are eligible for inclusion. The intervention group performs early controlled motion of the ankle in weeks 3-8 after rupture. The control group is immobilized. In total, 130 patients will be included from one big orthopedic center over a period of 2½ years. The primary outcome is the patient-reported Achilles tendon Total Rupture Score evaluated at 12 months post-injury. Secondary outcome measures are the heel-rise work test, Achilles tendon elongation, and the rate of re-rupture. The primary analysis will be conducted as intention-to-treat analyses. This trial is the first to investigate the safety and efficacy of early controlled motion in the treatment of acute Achilles tendon rupture in a randomized setup. The study uses the patient-reported outcome measure, the Achilles tendon Total Rupture Score, as the primary endpoint, as it is believed to be the best surrogate measure for the tendon's actual capability to function in everyday life. ClinicalTrials.gov: NCT02015364 . Registered on 13 December 2013.

Selective decontamination of the digestive tract in gastrointestinal surgery: useful in infection prevention? A systematic review.

PubMed

Abis, Gabor S A; Stockmann, Hein B A C; van Egmond, Marjolein; Bonjer, Hendrik J; Vandenbroucke-Grauls, Christina M J E; Oosterling, Steven J

2013-12-01

Gastrointestinal surgery is associated with a high incidence of infectious complications. Selective decontamination of the digestive tract is an antimicrobial prophylaxis regimen that aims to eradicate gastrointestinal carriage of potentially pathogenic microorganisms and represents an adjunct to regular prophylaxis in surgery. Relevant studies were identified using bibliographic searches of MEDLINE, EMBASE, and the Cochrane database (period from 1970 to November 1, 2012). Only studies investigating selective decontamination of the digestive tract in gastrointestinal surgery were included. Two randomized clinical trials and one retrospective case-control trial showed significant benefit in terms of infectious complications and anastomotic leakage in colorectal surgery. Two randomized controlled trials in esophageal surgery and two randomized clinical trials in gastric surgery reported lower levels of infectious complications. Selective decontamination of the digestive tract reduces infections following esophageal, gastric, and colorectal surgeries and also appears to have beneficial effects on anastomotic leakage in colorectal surgery. We believe these results provide the basis for a large multicenter prospective study to investigate the role of selective decontamination of the digestive tract in colorectal surgery.

Effect of Ginger Supplementation on Proinflammatory Cytokines in Older Patients with Osteoarthritis: Outcomes of a Randomized Controlled Clinical Trial.

PubMed

Mozaffari-Khosravi, Hassan; Naderi, Zahra; Dehghan, Ali; Nadjarzadeh, Azadeh; Fallah Huseini, Hassan

2016-01-01

There is limited evidence that ginger powder consumption can relieve pain and inflammation due to specific anti-inflammatory phytochemical constitutents. This study investigates the effect of ginger supplementation on proinflammatory factors in participants (n = 120) of a randomized double-blind placebo-controlled 3-month clinical trial investigating knee osteoarthritis. Patients were randomly assigned to one of two groups: the ginger group (GG) or the placebo group (PG). Administered daily for 3 months, participants in the GG intervention received capsules containing 500 mg of ginger powder, while PG participants received capsules filled with 500 mg starch. Serum samples collected at baseline and 3 months were analyzed for serum levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). At baseline, proinflammatory cytokine concentrations did not differ by group. However, at 3 months, both cytokines decreased in the GG relative to the PG. The results of this study indicate that ginger supplementation may have a promising benefits for knee osteoarthritis and may, therefore, may warrant further study.

On coherent oscillations of a string.

NASA Technical Reports Server (NTRS)

Liu, C. H.

1972-01-01

Vibrations of an elastic string when the separation between the ends varies randomly are studied. The emphasis is on the evolution of the coherent, or ordered, oscillations of the string. Using a perturbation technique borrowed from quantum field theory and the modified Kryloff-Bogoliuboff method, the 'multiple scattering' effect of the random separation between the ends on the linear and nonlinear coherent oscillations are investigated. It is found that due to the random interactions the coherent fundamental oscillation as well as the harmonies are damped. Their frequencies are also modified.

Safety and efficacy of conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation: randomized controlled trial in adult renal transplantation.

PubMed

Oh, Chang-Kwon; Huh, Kyu Ha; Lee, Jong Soo; Cho, Hong Rae; Kim, Yu Seun

2014-09-01

The purpose of this study was to compare once-daily tacrolimus with twice-daily tacrolimus in terms of safety, efficacy, and patient satisfaction. This prospective, randomized, open-label, multicenter study was conducted at three institutes. Patients in the investigational group were converted from tacrolimus twice daily to the same dose of extended-release tacrolimus once daily at 1 month post-transplantation, while patients in the control group were maintained on tacrolimus twice daily. The efficacies, safeties, and patient satisfaction for the two drugs at 6 months post-transplantation were compared. Sixty patients were enrolled and randomized to the investigational group (28 of 29 patients completed the study) or the control group (26 of 31 patients completed the study). At 6 months post-transplantation, composite efficacy failure rates including the incidences of biopsy-confirmed acute rejection in the investigational and control groups were 0% and 10.7%, respectively; patient survival was 100% in each group. No difference in estimated glomerular filtration rate values were observed at 6 months post-transplantation (p=0.97). The safety and satisfaction profile (immunosuppressant therapy barrier scale) of once-daily tacrolimus was comparable with that of twice-daily tacrolimus (p=0.35). Conversion from twice-daily tacrolimus to once-daily tacrolimus one month after transplantation is safe and effective.

Emotional, Social, Educational Adjustment of Higher Secondary School Students in Relation to Academic Achievement

ERIC Educational Resources Information Center

Sekar, J. Master Arul; Lawrence, A.S. Arul

2016-01-01

The present study aims to investigate whether there is any significant relationship between adjustment and academic achievement of higher secondary school students. In this survey study, the investigators used stratified random sampling technique for selecting the sample from the population. The stratification was done on the basis of gender and…

Observational Studies: Cohort and Case-Control Studies

PubMed Central

Song, Jae W.; Chung, Kevin C.

2010-01-01

Observational studies are an important category of study designs. To address some investigative questions in plastic surgery, randomized controlled trials are not always indicated or ethical to conduct. Instead, observational studies may be the next best method to address these types of questions. Well-designed observational studies have been shown to provide results similar to randomized controlled trials, challenging the belief that observational studies are second-rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. In this review article, we describe these study designs, methodological issues, and provide examples from the plastic surgery literature. PMID:20697313

Balneotherapy in fibromyalgia: a single blind randomized controlled clinical study.

PubMed

Ozkurt, Seçil; Dönmez, Arif; Zeki Karagülle, M; Uzunoğlu, Emel; Turan, Mustafa; Erdoğan, Nergis

2012-07-01

We aimed to evaluate the effectiveness of balneotherapy in fibromyalgia management. Fifty women with fibromyalgia under pharmacological treatment were randomly assigned to either the balneotherapy (25) or the control (25) group. Four patients from the balneotherapy group and one patient from the control group left the study after randomization. The patients in the balneotherapy group (21) had 2 thermomineral water baths daily for 2 weeks in Tuzla Spa Center. The patients in the control group (24) continued to have their medical treatment and routine daily life. An investigator who was blinded to the study arms assessed the patients. All patients were assessed four times; at the beginning of the study, at the end of the 2nd week, the 1st month, and the 3rd month after balneotherapy. Outcome measures of the study were pain intensity, Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory (BDI), patient's global assessment, investigator's global assessment, SF-36 scores, and tender point count. Balneotherapy was found to be superior at the end of the cure period in terms of pain intensity, FIQ, Beck Depression Inventory, patient's global assessment, investigator's global assessment scores, and tender point count as compared to the control group. The superiority of balneotherapy lasted up to the end of the 3rd month, except for the Beck Depression Inventory score and the investigator's global assessment score. Significant improvements were observed in PF, GH, and MH subscales of SF-36 during the study period in the balneotherapy group; however, no such improvement was observed in the control group. Balneotherapy was superior only in VT subscale at the end of therapy and at the end of the third month after the therapy as compared to the controls. It was concluded that balneotherapy provides beneficial effects in patients with fibromyalgia.

Numerical simulation of a shear-thinning fluid through packed spheres

NASA Astrophysics Data System (ADS)

Liu, Hai Long; Moon, Jong Sin; Hwang, Wook Ryol

2012-12-01

Flow behaviors of a non-Newtonian fluid in spherical microstructures have been studied by a direct numerical simulation. A shear-thinning (power-law) fluid through both regular and randomly packed spheres has been numerically investigated in a representative unit cell with the tri-periodic boundary condition, employing a rigorous three-dimensional finite-element scheme combined with fictitious-domain mortar-element methods. The present scheme has been validated for the classical spherical packing problems with literatures. The flow mobility of regular packing structures, including simple cubic (SC), body-centered cubic (BCC), face-centered cubic (FCC), as well as randomly packed spheres, has been investigated quantitatively by considering the amount of shear-thinning, the pressure gradient and the porosity as parameters. Furthermore, the mechanism leading to the main flow path in a highly shear-thinning fluid through randomly packed spheres has been discussed.

Lessons learned in research: an attempt to study the effects of magnetic therapy.

PubMed

Szor, Judy K; Holewinski, Paul

2002-02-01

Difficulties related to chronic wound healing research are frequently discussed, but results of less-than-perfect studies commonly are not published. A 16-week, randomized controlled double-blind study attempted to investigate the effect of static magnetic therapy on the healing of diabetic foot ulcers. Of 56 subjects, 37 completed the study. Because of the small sample size, randomization did not control for differences between the two groups, and the data could not be analyzed in any meaningful way. The challenges of performing magnetic therapy research are discussed and considerations for future studies are noted.

Observational studies are complementary to randomized controlled trials.

PubMed

Grootendorst, Diana C; Jager, Kitty J; Zoccali, Carmine; Dekker, Friedo W

2010-01-01

Randomized controlled trials (RCTs) are considered the gold standard study design to investigate the effect of health interventions, including treatment. However, in some situations, it may be unnecessary, inappropriate, impossible, or inadequate to perform an RCT. In these special situations, well-designed observational studies, including cohort and case-control studies, may provide an alternative to doing nothing in order to obtain estimates of treatment effect. It should be noted that such studies should be performed with caution and correctly. The aims of this review are (1) to explain why RCTs are considered the optimal study design to evaluate treatment effects, (2) to describe the situations in which an RCT is not possible and observational studies are an adequate alternative, and (3) to explain when randomization is not needed and can be approximated in observational studies. Examples from the nephrology literature are used for illustration. Copyright 2009 S. Karger AG, Basel.

Investigation of the Effects of Brain Teasers on Attention Spans of Pre-School Children

ERIC Educational Resources Information Center

Altun, Meryem; Hazar, Muhsin; Hazar, Zekihan

2016-01-01

The purpose of this study is to investigate the effects of brain teasers on attention spans of preschool children of age six. The study was conducted using an experimental design with a control group and pre-test/post-test. The sample of the study is children of age six selected via random appointment among ones who were enrolled in the Merkez…

Parameter identification using a creeping-random-search algorithm

NASA Technical Reports Server (NTRS)

Parrish, R. V.

1971-01-01

A creeping-random-search algorithm is applied to different types of problems in the field of parameter identification. The studies are intended to demonstrate that a random-search algorithm can be applied successfully to these various problems, which often cannot be handled by conventional deterministic methods, and, also, to introduce methods that speed convergence to an extremal of the problem under investigation. Six two-parameter identification problems with analytic solutions are solved, and two application problems are discussed in some detail. Results of the study show that a modified version of the basic creeping-random-search algorithm chosen does speed convergence in comparison with the unmodified version. The results also show that the algorithm can successfully solve problems that contain limits on state or control variables, inequality constraints (both independent and dependent, and linear and nonlinear), or stochastic models.

Investigator-reported efficacy of azelaic acid foam 15% in patients with papulopustular rosacea: secondary efficacy outcomes from a randomized, controlled, double-blind, phase 3 trial.

PubMed

Solomon, James A; Tyring, Stephen; Staedtler, Gerald; Sand, Meike; Nkulikiyinka, Richard; Shakery, Kaweh

2016-09-01

Papulopustular rosacea (PPR) is characterized by centrofacial papules and pustules commonly associated with erythema. To compare investigator-reported efficacy outcomes for azelaic acid (AzA) foam 15% versus vehicle foam in PPR, a randomized, vehicle-controlled, double-blind phase 3 clinical trial was conducted at 48 US sites. Participants received AzA foam or vehicle foam for 12 weeks. Secondary efficacy outcomes included change in inflammatory lesion count (ILC), therapeutic response rate according to investigator global assessment (IGA), and change in erythema rating. This study was comprised of 961 participants with PPR. The results support the therapeutic superiority of AzA foam over vehicle foam.

The efficacy of anticonvulsants on orofacial pain: a systematic review.

PubMed

Martin, Wilhelmus J J M; Forouzanfar, Tymour

2011-05-01

Controversy exists about the effectiveness of anticonvulsants for the management of orofacial pain disorders. To ascertain appropriate therapies, a systematic review was conducted of existing randomized controlled trials. Trials were identified from PubMed, Cochrane, and Ovid Medline databases from 1962 through March 2010, from references in retrieved reports, and from references in review articles. Eight useful trials were identified for this review. Six studies were randomized placebo-controlled trials and 2 studies were randomized active-controlled. Two independent investigators reviewed these articles by using a 15-item checklist. Four studies were classified as "high quality." However, heterogeneity of the trials and the small sample sizes precluded the drawing of firm conclusions about the efficacy of the interventions studied on orofacial pain patients. There is limited to moderate evidence supporting the efficacy of commonly used anticonvulsants for treatment of patients with orofacial pain disorders. More randomized controlled trials are needed on the efficacy of anticonvulsants. Copyright © 2011 Mosby, Inc. All rights reserved.

Recruitment methods and costs for a randomized, placebo-controlled trial of chiropractic care for lumbar spinal stenosis: a single-site pilot study.

PubMed

Cambron, Jerrilyn A; Dexheimer, Jennifer M; Chang, Mabel; Cramer, Gregory D

2010-01-01

The purpose of this article is to describe the methods for recruitment in a clinical trial on chiropractic care for lumbar spinal stenosis. This randomized, placebo-controlled pilot study investigated the efficacy of different amounts of total treatment dosage over 6 weeks in 60 volunteer subjects with lumbar spinal stenosis. Subjects were recruited for this study through several media venues, focusing on successful and cost-effective strategies. Included in our efforts were radio advertising, newspaper advertising, direct mail, and various other low-cost initiatives. Of the 1211 telephone screens, 60 responders (5.0%) were randomized into the study. The most successful recruitment method was radio advertising, generating more than 64% of the calls (776 subjects). Newspaper and magazine advertising generated approximately 9% of all calls (108 subjects), and direct mail generated less than 7% (79 subjects). The total direct cost for recruitment was $40 740 or $679 per randomized patient. The costs per randomization were highest for direct mail ($995 per randomization) and lowest for newspaper/magazine advertising ($558 per randomization). Success of recruitment methods may vary based on target population and location. Planning of recruitment efforts is essential to the success of any clinical trial. Copyright 2010 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

A Comparison of Psychoanalytic Therapy and Cognitive Behavioral Therapy for Anxiety (Panic/Agoraphobia) and Personality Disorders (APD Study): Presentation of the RCT Study Design.

PubMed

Benecke, Cord; Huber, Dorothea; Staats, Hermann; Zimmermann, Johannes; Henkel, Miriam; Deserno, Heinrich; Wiegand-Grefe, Silke; Schauenburg, Henning

2016-09-01

Anxiety disorders, most notably panic disorders and agoraphobia, are common mental disorders, and there is a high comorbidity with personality disorders. Randomized controlled trails addressing this highly relevant group of patients are missing. The multicenter Anxiety and Personality Disorders (APD) study investigates 200 patients with panic disorder and/or agoraphobia with comorbid personality disorder in a randomized control-group comparison of psychoanalytic therapy (PT) and cognitive behavioral therapy (CBT), including 100 patients in each group. Each patient will be examined over a period of six years, regardless of the duration of the individual treatment. The main issues that are addressed in this study are the comparison of the efficacy of PT and CBT in this special patient population, the comparison of the sustainability of the effects of PT and CBT, the comparison of the long-term cost-benefit-ratios of PT and CBT as well as the investigation of prescriptive patient characteristics for individualized treatment recommendations (differential indication). The APD study compares efficacy, sustainability, and cost-benefit-ratios of CBT and PT for anxiety plus personality disorders in a randomized controlled trail. The study design meets the requirements for an efficacy study for PT, which were recently defined. Current Controlled Trials ISRCTN12449681.

Random-effects meta-analysis: the number of studies matters.

PubMed

Guolo, Annamaria; Varin, Cristiano

2017-06-01

This paper investigates the impact of the number of studies on meta-analysis and meta-regression within the random-effects model framework. It is frequently neglected that inference in random-effects models requires a substantial number of studies included in meta-analysis to guarantee reliable conclusions. Several authors warn about the risk of inaccurate results of the traditional DerSimonian and Laird approach especially in the common case of meta-analysis involving a limited number of studies. This paper presents a selection of likelihood and non-likelihood methods for inference in meta-analysis proposed to overcome the limitations of the DerSimonian and Laird procedure, with a focus on the effect of the number of studies. The applicability and the performance of the methods are investigated in terms of Type I error rates and empirical power to detect effects, according to scenarios of practical interest. Simulation studies and applications to real meta-analyses highlight that it is not possible to identify an approach uniformly superior to alternatives. The overall recommendation is to avoid the DerSimonian and Laird method when the number of meta-analysis studies is modest and prefer a more comprehensive procedure that compares alternative inferential approaches. R code for meta-analysis according to all of the inferential methods examined in the paper is provided.

Modeling for Ultrasonic Health Monitoring of Foams with Embedded Sensors

NASA Technical Reports Server (NTRS)

Wang, L.; Rokhlin, S. I.; Rokhlin, Stanislav, I.

2005-01-01

In this report analytical and numerical methods are proposed to estimate the effective elastic properties of regular and random open-cell foams. The methods are based on the principle of minimum energy and on structural beam models. The analytical solutions are obtained using symbolic processing software. The microstructure of the random foam is simulated using Voronoi tessellation together with a rate-dependent random close-packing algorithm. The statistics of the geometrical properties of random foams corresponding to different packing fractions have been studied. The effects of the packing fraction on elastic properties of the foams have been investigated by decomposing the compliance into bending and axial compliance components. It is shown that the bending compliance increases and the axial compliance decreases when the packing fraction increases. Keywords: Foam; Elastic properties; Finite element; Randomness

Effectiveness of deep versus moderate muscle relaxation during laparoscopic donor nephrectomy in enhancing postoperative recovery: study protocol for a randomized controlled study.

PubMed

Bruintjes, Moira H D; Braat, Andries E; Dahan, Albert; Scheffer, Gert-Jan; Hilbrands, Luuk B; d'Ancona, Frank C H; Donders, Rogier A R T; van Laarhoven, Cornelis J H M; Warlé, Michiel C

2017-03-04

Postoperative recovery after live donor nephrectomy is largely determined by the consequences of postoperative pain and analgesia consumptions. The use of deep neuromuscular blockade has been shown to reduce postoperative pain scores after laparoscopic surgery. In this study, we will investigate whether deep neuromuscular blockade also improves the early quality of recovery after live donor nephrectomy. The RELAX-study is a phase IV, multicenter, double-blinded, randomized controlled trial, in which 96 patients, scheduled for living donor nephrectomy, will be randomized into two groups: one with deep and one with moderate neuromuscular blockade. Deep neuromuscular blockade is defined as a post-tetanic count of 1-2. Our primary outcome measurement will be the Quality of Recovery-40 questionnaire (overall score) at 24 h after extubation. This study is, to our knowledge, the first randomized study to assess the effectiveness of deep neuromuscular blockade during laparoscopic donor nephrectomy in enhancing postoperative recovery. The study findings may also be applicable for other laparoscopic procedures. clinicaltrials.gov, NCT02838134 . Registered on 29 June 2016.

Mass media influence spreading in social networks with community structure

NASA Astrophysics Data System (ADS)

Candia, Julián; Mazzitello, Karina I.

2008-07-01

We study an extension of Axelrod's model for social influence, in which cultural drift is represented as random perturbations, while mass media are introduced by means of an external field. In this scenario, we investigate how the modular structure of social networks affects the propagation of mass media messages across a society. The community structure of social networks is represented by coupled random networks, in which two random graphs are connected by intercommunity links. Considering inhomogeneous mass media fields, we study the conditions for successful message spreading and find a novel phase diagram in the multidimensional parameter space. These findings show that social modularity effects are of paramount importance for designing successful, cost-effective advertising campaigns.

Strength and Agility Training in Adolescents with Down Syndrome: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Lin, Hsiu-Ching; Wuang, Yee-Pay

2012-01-01

The purpose of this study was to investigate the effects of a proposed strength and agility training program of adolescents with Down syndrome. Ninety-two adolescents were recruited and evenly randomized to two intervention groups (exercise group vs. control group). The mean age for the exercise and the control group was 10.6 plus or minus 3.2 and…

Factors Associated with High Use of a Workplace Web-Based Stress Management Program in a Randomized Controlled Intervention Study

ERIC Educational Resources Information Center

Hasson, H.; Brown, C.; Hasson, D.

2010-01-01

In web-based health promotion programs, large variations in participant engagement are common. The aim was to investigate determinants of high use of a worksite self-help web-based program for stress management. Two versions of the program were offered to randomly selected departments in IT and media companies. A static version of the program…

The Long-Term Effectiveness of a Selective, Personality-Targeted Prevention Program in Reducing Alcohol Use and Related Harms: A Cluster Randomized Controlled Trial

ERIC Educational Resources Information Center

Newton, Nicola C.; Conrod, Patricia J.; Slade, Tim; Carragher, Natacha; Champion, Katrina E.; Barrett, Emma L.; Kelly, Erin V.; Nair, Natasha K.; Stapinski, Lexine; Teesson, Maree

2016-01-01

Background: This study investigated the long-term effectiveness of Preventure, a selective personality-targeted prevention program, in reducing the uptake of alcohol, harmful use of alcohol, and alcohol-related harms over a 3-year period. Methods: A cluster randomized controlled trial was conducted to assess the effectiveness of Preventure.…

Timing the Random and Anomalous Arrival of Particles in a Geiger Counter with GPS Devices

ERIC Educational Resources Information Center

Blanco, F.; La Rocca, P.; Riggi, F.; Riggi, S.

2008-01-01

The properties of the arrival time distribution of particles in a detector have been studied by the use of a small Geiger counter, with a GPS device to tag the event time. The experiment is intended to check the basic properties of the random arrival time distribution between successive events and to simulate the investigations carried out by…

School-Based Prevention of Depressive Symptoms: A Randomized Controlled Study of the Effectiveness and Specificity of the Penn Resiliency Program

ERIC Educational Resources Information Center

Gillham, Jane E.; Reivich, Karen J.; Freres, Derek R.; Chaplin, Tara M.; Shatte, Andrew J.; Samuels, Barbra; Elkon, Andrea G. L.; Litzinger, Samantha; Lascher, Marisa; Gallop, Robert; Seligman, Martin E. P.

2007-01-01

The authors investigated the effectiveness and specificity of the Penn Resiliency Program (PRP; J. E. Gillham, L. H. Jaycox, K. J. Reivich, M. E. P. Seligman, & T. Silver, 1990), a cognitive-behavioral depression prevention program. Children (N = 697) from 3 middle schools were randomly assigned to PRP, Control (CON), or the Penn Enhancement …

Group and Individual Treatment of Obsessive-Compulsive Disorder Using Cognitive Therapy and Exposure Plus Response Prevention: A 2-Year Follow-Up of Two Randomized Trials

ERIC Educational Resources Information Center

Whittal, Maureen L.; Robichaud, Melisa; Thordarson, Dana S.; McLean, Peter D.

2008-01-01

Relatively little is known about the long-term durability of group treatments for obsessive-compulsive disorder (OCD) and contemporary cognitive treatments. The current study investigated the 2-year follow-up results for participants who completed randomized trials of group or individual treatment and received either cognitive therapy (CT) or…

Continuous-time quantum random walks require discrete space

NASA Astrophysics Data System (ADS)

Manouchehri, K.; Wang, J. B.

2007-11-01

Quantum random walks are shown to have non-intuitive dynamics which makes them an attractive area of study for devising quantum algorithms for long-standing open problems as well as those arising in the field of quantum computing. In the case of continuous-time quantum random walks, such peculiar dynamics can arise from simple evolution operators closely resembling the quantum free-wave propagator. We investigate the divergence of quantum walk dynamics from the free-wave evolution and show that, in order for continuous-time quantum walks to display their characteristic propagation, the state space must be discrete. This behavior rules out many continuous quantum systems as possible candidates for implementing continuous-time quantum random walks.

Percolation of localized attack on isolated and interdependent random networks

NASA Astrophysics Data System (ADS)

Shao, Shuai; Huang, Xuqing; Stanley, H. Eugene; Havlin, Shlomo

2014-03-01

Percolation properties of isolated and interdependent random networks have been investigated extensively. The focus of these studies has been on random attacks where each node in network is attacked with the same probability or targeted attack where each node is attacked with a probability being a function of its centrality, such as degree. Here we discuss a new type of realistic attacks which we call a localized attack where a group of neighboring nodes in the networks are attacked. We attack a randomly chosen node, its neighbors, and its neighbor of neighbors and so on, until removing a fraction (1 - p) of the network. This type of attack reflects damages due to localized disasters, such as earthquakes, floods and war zones in real-world networks. We study, both analytically and by simulations the impact of localized attack on percolation properties of random networks with arbitrary degree distributions and discuss in detail random regular (RR) networks, Erdős-Rényi (ER) networks and scale-free (SF) networks. We extend and generalize our theoretical and simulation results of single isolated networks to networks formed of interdependent networks.

Bacteriophages for treating urinary tract infections in patients undergoing transurethral resection of the prostate: a randomized, placebo-controlled, double-blind clinical trial.

PubMed

Leitner, Lorenz; Sybesma, Wilbert; Chanishvili, Nina; Goderdzishvili, Marina; Chkhotua, Archil; Ujmajuridze, Aleksandre; Schneider, Marc P; Sartori, Andrea; Mehnert, Ulrich; Bachmann, Lucas M; Kessler, Thomas M

2017-09-26

Urinary tract infections (UTI) are among the most prevalent microbial diseases and their financial burden on society is substantial. The continuing increase of antibiotic resistance worldwide is alarming. Thus, well-tolerated, highly effective therapeutic alternatives are urgently needed. Although there is evidence indicating that bacteriophage therapy may be effective and safe for treating UTIs, the number of investigated patients is low and there is a lack of randomized controlled trials. This study is the first randomized, placebo-controlled, double-blind trial investigating bacteriophages in UTI treatment. Patients planned for transurethral resection of the prostate are screened for UTIs and enrolled if in urine culture eligible microorganisms ≥10 4 colony forming units/mL are found. Patients are randomized in a double-blind fashion to the 3 study treatment arms in a 1:1:1 ratio to receive either: a) bacteriophage (i.e. commercially available Pyo bacteriophage) solution, b) placebo solution, or c) antibiotic treatment according to the antibiotic sensitivity pattern. All treatments are intended for 7 days. No antibiotic prophylaxes will be given to the double-blinded treatment arms a) and b). As common practice, the Pyo bacteriophage cocktail is subjected to periodic adaptation cycles during the study. Urinalysis, urine culture, bladder and pain diary, and IPSS questionnaire will be completed prior to and at the end of treatment (i.e. after 7 days) or at withdrawal/drop out from the study. Patients with persistent UTIs will undergo antibiotic treatment according to antibiotic sensitivity pattern. Based on the high lytic activity and the potential of resistance optimization by direct adaptation of bacteriophages, and considering the continuing increase of antibiotic resistance worldwide, bacteriophage therapy is a very promising treatment option for UTIs. Thus, our randomized controlled trial investigating bacteriophages for treating UTIs will provide essential insights into this potentially revolutionizing treatment option. This study has been registered at clinicaltrials.gov ( www.clinicaltrials.gov/ct2/show/NCT03140085 ). April 27, 2017.

Systematic review of physiotherapy interventions to improve gross motor capacity and performance in children and adolescents with an acquired brain injury.

PubMed

Baque, Emmah; Sakzewski, Leanne; Barber, Lee; Boyd, Roslyn N

2016-01-01

To systematically review the efficacy of physiotherapy interventions to improve gross motor capacity, performance and societal participation in children aged 5-17 years with an acquired brain injury (ABI). Randomized and non-randomized controlled trials, cohort, case series, case-control and case studies were included and classified according to grades of evidence. Methodological quality of studies was assessed using the Downs and Black (D&B) scale and quantitative data was analysed using effect sizes. Two home-based studies investigated functional strength training (one randomized controlled trial, n = 20, level 2b, D&B = 16/32 and one non-randomized self-control study, n = 19, level 4, D&B = 15/32). Four studies evaluated virtual reality including: one pilot study, n = 50, level 4, D&B = 22/32; one single-subject, non-concurrent, randomized multiple baseline study, n = 3, level 4, D&B = 15/32; one case series study, n = 2, level 4, D&B = 15/32; one case study, n = 1, level 4, D&B = 15/32. Effect sizes for the randomized controlled trial ranged between 0.30-1.29 for the Functional Reach and Timed Up and Go outcome measures. There is preliminary evidence to support the efficacy of physiotherapy interventions to improve gross motor outcomes in children with an ABI. Both functional strength training and virtual-reality based therapy are potential treatment options for clinicians to prescribe in either home or clinical settings.

Distinguishability of generic quantum states

NASA Astrophysics Data System (ADS)

Puchała, Zbigniew; Pawela, Łukasz; Życzkowski, Karol

2016-06-01

Properties of random mixed states of dimension N distributed uniformly with respect to the Hilbert-Schmidt measure are investigated. We show that for large N , due to the concentration of measure, the trace distance between two random states tends to a fixed number D ˜=1 /4 +1 /π , which yields the Helstrom bound on their distinguishability. To arrive at this result, we apply free random calculus and derive the symmetrized Marchenko-Pastur distribution, which is shown to describe numerical data for the model of coupled quantum kicked tops. Asymptotic value for the root fidelity between two random states, √{F }=3/4 , can serve as a universal reference value for further theoretical and experimental studies. Analogous results for quantum relative entropy and Chernoff quantity provide other bounds on the distinguishablity of both states in a multiple measurement setup due to the quantum Sanov theorem. We study also mean entropy of coherence of random pure and mixed states and entanglement of a generic mixed state of a bipartite system.

Membrane fouling in a submerged membrane bioreactor: An unified approach to construct topography and to evaluate interaction energy between two randomly rough surfaces.

PubMed

Cai, Xiang; Shen, Liguo; Zhang, Meijia; Chen, Jianrong; Hong, Huachang; Lin, Hongjun

2017-11-01

Quantitatively evaluating interaction energy between two randomly rough surfaces is the prerequisite to quantitatively understand and control membrane fouling in membrane bioreactors (MBRs). In this study, a new unified approach to construct rough topographies and to quantify interaction energy between a randomly rough particle and a randomly rough membrane was proposed. It was found that, natural rough topographies of both foulants and membrane could be well constructed by a modified two-variable Weierstrass-Mandelbrot (WM) function included in fractal theory. Spatial differential relationships between two constructed surfaces were accordingly established. Thereafter, a new approach combining these relationships, surface element integration (SEI) approach and composite Simpson's rule was deduced to calculate the interaction energy between two randomly rough surfaces in a submerged MBR. The obtained results indicate the profound effects of surface morphology on interaction energy and membrane fouling. This study provided a basic approach to investigate membrane fouling and interface behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Foreign Language Anxiety on Gender and Academic Achievement among Yemeni University EFL Students

ERIC Educational Resources Information Center

Razak, Norizan Abdul; Yassin, Amr Abdullatif; Maasum, Tengku Nor Rizan Bt Tengku Mohamad

2017-01-01

This study aimed to investigate the gender differences in terms of anxiety among Yemeni university EFL learners. It also aimed to investigate the correlation between the level of anxiety and the academic achievement of the students. The participants of this study were 155 students chosen from the population through stratified random sampling. The…

Investigation of Coefficient of Individual Agreement in Terms of Sample Size, Random and Monotone Missing Ratio, and Number of Repeated Measures

ERIC Educational Resources Information Center

Temel, Gülhan Orekici; Erdogan, Semra; Selvi, Hüseyin; Kaya, Irem Ersöz

2016-01-01

Studies based on longitudinal data focus on the change and development of the situation being investigated and allow for examining cases regarding education, individual development, cultural change, and socioeconomic improvement in time. However, as these studies require taking repeated measures in different time periods, they may include various…

Investigating methotrexate toxicity within a randomized double-blinded, placebo-controlled trial: rationale and design of the Cardiovascular Inflammation Reduction Trial-Adverse Events (CIRT-AE) Study

USDA-ARS?s Scientific Manuscript database

Background: The role of low dose methotrexate (LDM) in potential serious toxicities remains unclear despite its common use. Prior observational studies investigating LDM toxicity compared LDM to other active drugs. Prior placebo-controlled clinical trials of LDM in inflammatory conditions were not l...

Investigation of the Relationship between Communication Skills, Social Competence and Emotion Regulation Skills of Preschool Children in Turkey

ERIC Educational Resources Information Center

Dagal, A. B.

2017-01-01

The aim of this study is to investigate the relationship between communication skills, social competence and emotion regulation skills of preschool children. Children attending public primary schools who were 53 to 80 months old from the middle socio-economic class were chosen randomly from Istanbul City center districts for this study. They were…

Prevalence of dental anomalies in Saudi orthodontic patients.

PubMed

Al-Jabaa, Aljazi H; Aldrees, Abdullah M

2013-07-01

This study aimed to investigate the prevalence of dental anomalies and study the association of these anomalies with different types of malocclusion in a random sample of Saudi orthodontic patients. Six hundred and two randomly selected pretreatment records including orthopantomographs (OPG), and study models were evaluated. The molar relationship was determined using pretreatment study models, and OPG were examined to investigate the prevalence of dental anomalies among the sample. The most common types of the investigated anomalies were: impaction followed by hypodontia, microdontia, macrodontia, ectopic eruption and supernumerary. No statistical significant correlations were observed between sex and dental anomalies. Dental anomalies were more commonly found in class I followed by asymmetric molar relation, then class II and finally class III molar relation. No malocclusion group had a statistically significant relation with any individual dental anomaly. The prevalence of dental anomalies among Saudi orthodontic patients was higher than the general population. Although, orthodontic patients have been reported to have high rates of dental anomalies, orthodontists often fail to consider this. If not detected, dental anomalies can complicate dental and orthodontic treatment; therefore, their presence should be carefully investigated during orthodontic diagnosis and considered during treatment planning.

An investigation of the safety and pharmacokinetics of the novel TRPV1 antagonist XEN-D0501 in healthy subjects

PubMed Central

Round, Patrick; Priestley, Anthony; Robinson, Jan

2011-01-01

AIMS XEN-D0501, a novel TRPV1 antagonist, is being developed to treat overactive bladder. This study investigated the safety and pharmacokinetics of repeat-dose XEN-D0501 in healthy subjects. METHODS The study was conducted in two parts. Part 1 was a double-blind, randomized, placebo-controlled, two-way crossover study in three cohorts of 12 young male subjects. Each subject received XEN-D0501 and placebo (in random order) twice daily for 13 days, with a final single dose on day 14. Doses of 1, 2.5 and 5 mg XEN-D0501 were investigated. Part 2 was an open-label, randomized, two-way crossover study in male and female subjects (45 to 65 years). Subjects received single doses of 5 mg XEN-D0501 under fasted and fed conditions in random order. Blood sampling and safety assessments were conducted throughout the study. RESULTS XEN-D0501 was rapidly absorbed (tmax generally 0.5–4 h post dose). XEN-D0501 exposure increased less than proportionally to dose over the range studied and exhibited minimal accumulation with twice daily dosing. Food had no clinically relevant effects on the pharmacokinetics of XEN-D0501. There were no severe or serious adverse events and all doses were well tolerated. A dose-related increase in body temperature was seen with XEN-D0501 which attenuated over time. Differences from placebo in mean maximum core body temperatures were 0.22°C, 0.5°C and 0.74°C following 1 mg, 2.5 mg and 5 mg twice daily XEN-D0501. The observed increase in body temperature was not considered to be of clinical concern. CONCLUSIONS XEN-D0501 appeared safe and well tolerated at doses up to 5 mg twice daily for 14 days in healthy subjects. PMID:21676011

A Randomized Controlled Pilot Trial of Oral N-Acetylcysteine in Children with Autism

PubMed Central

Hardan, Antonio Y.; Fung, Lawrence K.; Libove, Robin A.; Obukhanych, Tetyana V.; Nair, Surekha; Herzenberg, Leonore A.; Frazier, Thomas W.; Tirouvanziam, Rabindra

2016-01-01

Background An imbalance in the excitatory/inhibitory systems with abnormalities in the glutamatergic pathways has been implicated in the pathophysiology of autism. Furthermore, chronic redox imbalance was also recently linked to this disorder. The goal of this pilot study was to assess the feasibility of using oral N-acetylcysteine (NAC), a glutamatergic modulator and an antioxidant in the treatment of behavioral disturbance in children with autism. Methods This is a 12-week, double-blind, randomized, placebo-controlled study of NAC in children with autistic disorder. Subjects randomized to NAC were initiated at 900 mg daily for 4 weeks, then 900 mg twice-daily for 4 weeks and 900 mg three-times-daily for 4 weeks. The primary behavioral measure (Aberrant Behavior Checklist – Irritability subscale) and safety measures were performed at baseline, 4, 8, and 12 weeks. Secondary measures included the ABC-Stereotypy subscale, Repetitive Behavior Scale – Revised (RBS-R), and Social Responsiveness Scale (SRS). Results Thirty-three subjects (31 males, 2 females; aged 3.2–10.7 years) were randomized in the study. Follow-up data was available on fourteen subjects in the NAC group and fifteen in the placebo group. Oral NAC was well-tolerated with limited side effects. Compared to placebo, NAC resulted in significant improvements on ABC-Irritability subscale (F=6.80; p<.001; d=.96). Conclusions Data from this pilot investigation support the potential usefulness of NAC for treating irritability in children with autistic disorder. Large randomized controlled investigations are warranted. ClinicalTrials.gov Identifier NCT00627705 PMID:22342106

Parallel Mitogenome Sequencing Alleviates Random Rooting Effect in Phylogeography.

PubMed

Hirase, Shotaro; Takeshima, Hirohiko; Nishida, Mutsumi; Iwasaki, Wataru

2016-04-28

Reliably rooted phylogenetic trees play irreplaceable roles in clarifying diversification in the patterns of species and populations. However, such trees are often unavailable in phylogeographic studies, particularly when the focus is on rapidly expanded populations that exhibit star-like trees. A fundamental bottleneck is known as the random rooting effect, where a distant outgroup tends to root an unrooted tree "randomly." We investigated whether parallel mitochondrial genome (mitogenome) sequencing alleviates this effect in phylogeography using a case study on the Sea of Japan lineage of the intertidal goby Chaenogobius annularis Eighty-three C. annularis individuals were collected and their mitogenomes were determined by high-throughput and low-cost parallel sequencing. Phylogenetic analysis of these mitogenome sequences was conducted to root the Sea of Japan lineage, which has a star-like phylogeny and had not been reliably rooted. The topologies of the bootstrap trees were investigated to determine whether the use of mitogenomes alleviated the random rooting effect. The mitogenome data successfully rooted the Sea of Japan lineage by alleviating the effect, which hindered phylogenetic analysis that used specific gene sequences. The reliable rooting of the lineage led to the discovery of a novel, northern lineage that expanded during an interglacial period with high bootstrap support. Furthermore, the finding of this lineage suggested the existence of additional glacial refugia and provided a new recent calibration point that revised the divergence time estimation between the Sea of Japan and Pacific Ocean lineages. This study illustrates the effectiveness of parallel mitogenome sequencing for solving the random rooting problem in phylogeographic studies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Pharmacokinetics and Safety of Intravenous Murepavadin Infusion in Healthy Adult Subjects Administered Single and Multiple Ascending Doses.

PubMed

Wach, Achim; Dembowsky, Klaus; Dale, Glenn E

2018-04-01

Murepavadin is the first in class of the outer membrane protein-targeting antibiotics (OMPTA) and a pathogen-specific peptidomimetic antibacterial with a novel, nonlytic mechanism of action targeting Pseudomonas aeruginosa Murepavadin is being developed for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). The pharmacokinetics (PK) and safety of single and multiple doses of murepavadin were investigated in healthy male subjects. Part A of the study was a double-blind, randomized, placebo-controlled, single-ascending-dose investigation in 10 sequential cohorts where each cohort comprised 6 healthy male subjects; 4 subjects were randomized to murepavadin, and 2 subjects were randomized to placebo. Part B was a double-blind, randomized, placebo-controlled, multiple-ascending-dose investigation in 3 sequential cohorts. After a single dose of murepavadin, the geometric mean half-life (2.52 to 5.30 h), the total clearance (80.1 to 114 ml/h/kg), and the volume of distribution (415 to 724 ml/kg) were consistent across dose levels. The pharmacokinetics of the dosing regimens evaluated were dose proportional and linear. Murepavadin was well tolerated, adverse events were transient and generally mild, and no dose-limiting toxicity was identified. Copyright © 2018 American Society for Microbiology.

Polysilicon Gate Enhancement of the Random Dopant Induced Threshold Voltage Fluctuations in Sub-100 nm MOSFET's with Ultrathin Gate Oxide

NASA Technical Reports Server (NTRS)

Asenov, Asen; Saini, Subhash

2000-01-01

In this paper, we investigate various aspects of the polysilicon gate influence on the random dopant induced threshold voltage fluctuations in sub-100 nm MOSFET's with ultrathin gate oxides. The study is done by using an efficient statistical three-dimensional (3-D) "atomistic" simulation technique described else-where. MOSFET's with uniform channel doping and with low doped epitaxial channels have been investigated. The simulations reveal that even in devices with a single crystal gate the gate depletion and the random dopants in it are responsible for a substantial fraction of the threshold voltage fluctuations when the gate oxide is scaled-in the range of 1-2 nm. Simulation experiments have been used in order to separate the enhancement in the threshold voltage fluctuations due to an effective increase in the oxide thickness associated with the gate depletion from the direct influence of the random dopants in the gate depletion layer. The results of the experiments show that the both factors contribute to the enhancement of the threshold voltage fluctuations, but the effective increase in the oxide-thickness has a dominant effect in the investigated range of devices. Simulations illustrating the effect or the polysilicon grain boundaries on the threshold voltage variation are also presented.

Randomization in clinical trials: stratification or minimization? The HERMES free simulation software.

PubMed

Fron Chabouis, Hélène; Chabouis, Francis; Gillaizeau, Florence; Durieux, Pierre; Chatellier, Gilles; Ruse, N Dorin; Attal, Jean-Pierre

2014-01-01

Operative clinical trials are often small and open-label. Randomization is therefore very important. Stratification and minimization are two randomization options in such trials. The first aim of this study was to compare stratification and minimization in terms of predictability and balance in order to help investigators choose the most appropriate allocation method. Our second aim was to evaluate the influence of various parameters on the performance of these techniques. The created software generated patients according to chosen trial parameters (e.g., number of important prognostic factors, number of operators or centers, etc.) and computed predictability and balance indicators for several stratification and minimization methods over a given number of simulations. Block size and proportion of random allocations could be chosen. A reference trial was chosen (50 patients, 1 prognostic factor, and 2 operators) and eight other trials derived from this reference trial were modeled. Predictability and balance indicators were calculated from 10,000 simulations per trial. Minimization performed better with complex trials (e.g., smaller sample size, increasing number of prognostic factors, and operators); stratification imbalance increased when the number of strata increased. An inverse correlation between imbalance and predictability was observed. A compromise between predictability and imbalance still has to be found by the investigator but our software (HERMES) gives concrete reasons for choosing between stratification and minimization; it can be downloaded free of charge. This software will help investigators choose the appropriate randomization method in future two-arm trials.

A comparison of observation-level random effect and Beta-Binomial models for modelling overdispersion in Binomial data in ecology & evolution.

PubMed

Harrison, Xavier A

2015-01-01

Overdispersion is a common feature of models of biological data, but researchers often fail to model the excess variation driving the overdispersion, resulting in biased parameter estimates and standard errors. Quantifying and modeling overdispersion when it is present is therefore critical for robust biological inference. One means to account for overdispersion is to add an observation-level random effect (OLRE) to a model, where each data point receives a unique level of a random effect that can absorb the extra-parametric variation in the data. Although some studies have investigated the utility of OLRE to model overdispersion in Poisson count data, studies doing so for Binomial proportion data are scarce. Here I use a simulation approach to investigate the ability of both OLRE models and Beta-Binomial models to recover unbiased parameter estimates in mixed effects models of Binomial data under various degrees of overdispersion. In addition, as ecologists often fit random intercept terms to models when the random effect sample size is low (<5 levels), I investigate the performance of both model types under a range of random effect sample sizes when overdispersion is present. Simulation results revealed that the efficacy of OLRE depends on the process that generated the overdispersion; OLRE failed to cope with overdispersion generated from a Beta-Binomial mixture model, leading to biased slope and intercept estimates, but performed well for overdispersion generated by adding random noise to the linear predictor. Comparison of parameter estimates from an OLRE model with those from its corresponding Beta-Binomial model readily identified when OLRE were performing poorly due to disagreement between effect sizes, and this strategy should be employed whenever OLRE are used for Binomial data to assess their reliability. Beta-Binomial models performed well across all contexts, but showed a tendency to underestimate effect sizes when modelling non-Beta-Binomial data. Finally, both OLRE and Beta-Binomial models performed poorly when models contained <5 levels of the random intercept term, especially for estimating variance components, and this effect appeared independent of total sample size. These results suggest that OLRE are a useful tool for modelling overdispersion in Binomial data, but that they do not perform well in all circumstances and researchers should take care to verify the robustness of parameter estimates of OLRE models.

Ways of learning: Observational studies versus experiments

USGS Publications Warehouse

Shaffer, T.L.; Johnson, D.H.

2008-01-01

Manipulative experimentation that features random assignment of treatments, replication, and controls is an effective way to determine causal relationships. Wildlife ecologists, however, often must take a more passive approach to investigating causality. Their observational studies lack one or more of the 3 cornerstones of experimentation: controls, randomization, and replication. Although an observational study can be analyzed similarly to an experiment, one is less certain that the presumed treatment actually caused the observed response. Because the investigator does not actively manipulate the system, the chance that something other than the treatment caused the observed results is increased. We reviewed observational studies and contrasted them with experiments and, to a lesser extent, sample surveys. We identified features that distinguish each method of learning and illustrate or discuss some complications that may arise when analyzing results of observational studies. Findings from observational studies are prone to bias. Investigators can reduce the chance of reaching erroneous conclusions by formulating a priori hypotheses that can be pursued multiple ways and by evaluating the sensitivity of study conclusions to biases of various magnitudes. In the end, however, professional judgment that considers all available evidence is necessary to render a decision regarding causality based on observational studies.

Korean Books and FRBR: An Investigation

ERIC Educational Resources Information Center

Kim, Jeong-Hyen; Moon, Ji-Hyun

2010-01-01

Purpose: The purpose of this study is to investigate the characteristics of Korean books by analysing their "work types" based on the Functional Requirements for Bibliographic Records (FRBR) model. Design/methodology/approach: A total of 1,000 Korean books were randomly chosen from the Korean National Bibliography (KNB) 2008 at the…

Nothing Happens by Accident, or Does It? A Low Prior for Randomness Does Not Explain Belief in Conspiracy Theories.

PubMed

Dieguez, Sebastian; Wagner-Egger, Pascal; Gauvrit, Nicolas

2015-11-01

Belief in conspiracy theories has often been associated with a biased perception of randomness, akin to a nothing-happens-by-accident heuristic. Indeed, a low prior for randomness (i.e., believing that randomness is a priori unlikely) could plausibly explain the tendency to believe that a planned deception lies behind many events, as well as the tendency to perceive meaningful information in scattered and irrelevant details; both of these tendencies are traits diagnostic of conspiracist ideation. In three studies, we investigated this hypothesis and failed to find the predicted association between low prior for randomness and conspiracist ideation, even when randomness was explicitly opposed to malevolent human intervention. Conspiracy believers' and nonbelievers' perceptions of randomness were not only indistinguishable from each other but also accurate compared with the normative view arising from the algorithmic information framework. Thus, the motto "nothing happens by accident," taken at face value, does not explain belief in conspiracy theories. © The Author(s) 2015.

Effect of Increased Endometrial Thickness and Implantation Rate by Granulocyte Colony-Stimulating Factor on Unresponsive Thin Endometrium in Fresh In Vitro Fertilization Cycles: A Randomized Clinical Trial

PubMed Central

Sarvi, Fatemeh; Arabahmadi, Marjan; Alleyassin, Ashraf; Aghahosseini, Marzieh

2017-01-01

Background The correlation between endometrial thickness and receptivity has been mentioned in various studies. This study investigated the effect of granulocyte colony-stimulating factor in treating thin endometrium of infertile women who were chosen for in vitro fertilization in our infertility clinic in 2014 and 2015. Methods In this randomized clinical trial, 28 women who were chosen for in vitro fertilization and had endometrial thickness of less than 6 mm on the day of human chorionic gonadotropin (hCG) injection were included in the study. They were randomly divided into two groups: investigation and control groups. In investigation group (n = 13) one granulocyte colony-stimulating factor vial (300 micrograms in 1 mL) was infused into the uterus within five minutes by embryo transfer catheter. In control group (n = 15) 1 mL of saline was injected into the uterus with the same catheter. Results There were significant differences between the two groups in terms of means of endometrial thickness on oocyte retrieval day (P = 0.001), embryo transfer day (P = 0.001), hCG injections (P = 0.001), and implantation rates (P = 0.001). Conclusion Granulocyte colony-stimulating factor can increase endometrial thickness in women treated with in vitro fertilization. RCT Code is 201406046063N2. PMID:28791050

Preventive and Abortive Strategies for Stimulation Based Control of Epilepsy: A Computational Model Study.

PubMed

Koppert, Marc; Kalitzin, Stiliyan; Velis, Demetrios; Lopes Da Silva, Fernando; Viergever, Max A

2016-12-01

Epilepsy is a condition in which periods of ongoing normal EEG activity alternate with periods of oscillatory behavior characteristic of epileptic seizures. The dynamics of the transitions between the two states are still unclear. Computational models provide a powerful tool to explore the underlying mechanisms of such transitions, with the purpose of eventually finding therapeutic interventions for this debilitating condition. In this study, the possibility to postpone seizures elicited by a decrease of inhibition is investigated by using external stimulation in a realistic bistable neuronal model consisting of two interconnected neuronal populations representing pyramidal cells and interneurons. In the simulations, seizures are induced by slowly decreasing the conductivity of GABA[Formula: see text] synaptic channels over time. Since the model is bistable, the system will change state from the initial steady state (SS) to the limit cycle (LS) state because of internal noise, when the inhibition falls below a certain threshold. Several state-independent stimulations paradigms are simulated. Their effectiveness is analyzed for various stimulation frequencies and intensities in combination with periodic and random stimulation sequences. The distributions of the time to first seizure in the presence of stimulation are compared with the situation without stimulation. In addition, stimulation protocols targeted to specific subsystems are applied with the objective of counteracting the baseline shift due to decreased inhibition in the system. Furthermore, an analytical model is used to investigate the effects of random noise. The relation between the strength of random noise stimulation, the control parameter of the system and the transitions between steady state and limit cycle are investigated. The study shows that it is possible to postpone epileptic activity by targeted stimulation in a realistic neuronal model featuring bistability and that it is possible to stop seizures by random noise in an analytical model.

Water-Based Aerobic Training Successfully Improves Lipid Profile of Dyslipidemic Women: A Randomized Controlled Trial

ERIC Educational Resources Information Center

Costa, Rochelle Rocha; Pilla, Carmen; Buttelli, Adriana Cristine Koch; Barreto, Michelle Flores; Vieiro, Priscila Azevedo; Alberton, Cristine Lima; Bracht, Cláudia Gomes; Kruel, Luiz Fernando Martins

2018-01-01

Purpose: This study aimed to investigate the effects of water-based aerobic training on the lipid profile and lipoprotein lipase (LPL) levels in premenopausal women with dyslipidemia. Method: Forty women were randomly assigned to: aquatic training (WA; n = 20) or a control group (CG; n = 20). The WA group underwent 12 weeks of water-based interval…

The Effectiveness of Conflict Maps and the V-Shape Teaching Method in Science Conceptual Change among Eighth-Grade Students in Jordan

ERIC Educational Resources Information Center

Bawaneh, Ali Khalid Ali; Zain, Ahmad Nurulazam Md; Ghazali, Munirah

2010-01-01

The purpose of the present study is to investigate the effectiveness of Conflict Maps and the V-Shape method as teaching methods in bringing about conceptual change in science among primary eighth-grade students in Jordan. A randomly selected sample (N = 63) from the Bani Kenana region North of Jordan was randomly assigned to the two teaching…

Optoenergy storage and random walks assisted broadband amplification in Er3+-doped (Pb,La)(Zr,Ti)O3 disordered ceramics.

PubMed

Xu, Long; Zhao, Hua; Xu, Caixia; Zhang, Siqi; Zou, Yingyin K; Zhang, Jingwen

2014-02-01

A broadband optical amplification was observed and investigated in Er3+-doped electrostrictive ceramics of lanthanum-modified lead zirconate titanate under a corona atmosphere. The ceramic structure change caused by UV light, electric field, and random walks originated from the diffusive process in intrinsically disordered materials may all contribute to the optical amplification and the associated energy storage. Discussion based on optical energy storage and diffusive equations was given to explain the findings. Those experiments performed made it possible to study random walks and optical amplification in transparent ceramics materials.

Informed Consent to Study Purpose in Randomized Clinical Trials of Antibiotics, 1991 Through 2011.

PubMed

Doshi, Peter; Hur, Peter; Jones, Mark; Albarmawi, Husam; Jefferson, Tom; Morgan, Daniel J; Spears, Patricia A; Powers, John H

2017-10-01

Potential research participants may assume that randomized trials comparing new interventions with older interventions always hypothesize greater efficacy for the new intervention, as in superiority trials. However, antibiotic trials frequently use "noninferiority" hypotheses allowing a degree of inferior efficacy deemed "clinically acceptable" compared with an older effective drug, in exchange for nonefficacy benefits (eg, decreased adverse effects). Considering these different benefit-harm trade-offs, proper informed consent necessitates supplying different information on the purposes of superiority and noninferiority trials. To determine the degree to which the study purpose is explained to potential participants in randomized clinical trials of antibiotics and the degree to which study protocols justify their selection of noninferiority hypotheses and amount of "clinically acceptable" inferiority. Cross-sectional analysis of study protocols, statistical analysis plans (SAPs), and informed consent forms (ICFs) from clinical study reports submitted to the European Medicines Agency. The ICFs were read by both methodologists and patient investigators. Protocols and SAPs were used as the reference standard to determine prespecified primary hypothesis and record rationale for selection of noninferiority hypotheses and noninferiority margins. This information was cross-referenced against ICFs to determine whether ICFs explained the study purpose. We obtained trial documents from 78 randomized trials with prespecified efficacy hypotheses (6 superiority, 72 noninferiority) for 17 antibiotics conducted between 1991 and 2011 that enrolled 39 407 patients. Fifty were included in the ICF analysis. All ICFs contained sections describing study purpose; however, none consistently conveyed study hypothesis to both methodologists and patient investigators. Methodologists found that 1 of 50 conveyed a study purpose. Patient investigators found that 11 of 50 conveyed a study purpose, 7 accurately and 4 inaccurately compared with the reference standard. Seventy-one of 72 noninferiority trial protocols or SAPs provided no rationale for selection of noninferiority hypothesis. None provided a clinical rationale for the chosen amount of decreased efficacy. Patients were not accurately informed of study purpose, which raises questions regarding the ethics of informed consent in antibiotic trials. Noninferiority and superiority trials entail different benefit-harm trade-offs that must be conveyed for ethical informed consent.

Characterization of nitride hole lateral transport in a charge trap flash memory by using a random telegraph signal method

NASA Astrophysics Data System (ADS)

Liu, Yu-Heng; Jiang, Cheng-Min; Lin, Hsiao-Yi; Wang, Tahui; Tsai, Wen-Jer; Lu, Tao-Cheng; Chen, Kuang-Chao; Lu, Chih-Yuan

2017-07-01

We use a random telegraph signal method to investigate nitride trapped hole lateral transport in a charge trap flash memory. The concept of this method is to utilize an interface oxide trap and its associated random telegraph signal as an internal probe to detect a local channel potential change resulting from nitride charge lateral movement. We apply different voltages to the drain of a memory cell and vary a bake temperature in retention to study the electric field and temperature dependence of hole lateral movement in a nitride. Thermal energy absorption by trapped holes in lateral transport is characterized. Mechanisms of hole lateral transport in retention are investigated. From the measured and modeled results, we find that thermally assisted trap-to-band tunneling is a major trapped hole emission mechanism in nitride hole lateral transport.

The SimpleMix study with biphasic insulin aspart 30: a randomized controlled trial investigating patient-driven titration versus investigator-driven titration.

PubMed

Gao, Yan; Luquez, Cecilia; Lynggaard, Helle; Andersen, Henning; Saboo, Banshi

2014-12-01

The study aimed to confirm the efficacy, through non-inferiority, of patient-driven versus investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) in terms of glycemic control assessed by HbA1c change. SimpleMix was a 20 week, open-label, randomized, two-armed, parallel-group, multicenter study in five countries (Argentina, China, India, Poland, and the UK). Patients with type 2 diabetes were randomized into either patient-driven or investigator-driven BIAsp 30 titration groups. Non-inferiority of patient-driven vs. investigator-driven titration based on change in HbA1c from baseline to week 20 could not be demonstrated. Mean (SE) estimated change from baseline to week 20 was -0.72 (0.08)% in the patient-driven group and -0.97 (0.08)% in the investigator-driven group; estimated difference 0.25% (95% CI: 0.04; 0.46). Estimated mean change (SE) in fasting plasma glucose from baseline to week 20 was similar between groups: -0.94 (0.21) mmol/L for patient-driven and -1.07 (0.22) mmol/L for investigator-driven (difference non-significant). Both treatment arms were well tolerated, and hypoglycemic episode rates were similar between groups, with a rate ratio of 0.77 (95% CI: 0.54; 1.09; p = 0.143) for all hypoglycemic episodes and 0.78 (95% CI: 0.42; 1.43; p = 0.417) for nocturnal hypoglycemic episodes. Non-inferiority of patient-driven versus investigator-driven titration with regard to change from baseline to end-of-treatment HbA1c could not be confirmed. It is possible that a clinic visit 12 weeks after intensification of treatment with BIAsp 30 in patients with type 2 diabetes inadequately treated with basal insulin may benefit patient-driven titration of BIAsp 30. A limitation of the study was the relatively small number of patients recruited in each country, which does not allow country-specific analyses to be performed. Overall, treatment with BIAsp 30 was well tolerated in both treatment groups.

Using Exponential Random Graph Models to Analyze the Character of Peer Relationship Networks and Their Effects on the Subjective Well-being of Adolescents.

PubMed

Jiao, Can; Wang, Ting; Liu, Jianxin; Wu, Huanjie; Cui, Fang; Peng, Xiaozhe

2017-01-01

The influences of peer relationships on adolescent subjective well-being were investigated within the framework of social network analysis, using exponential random graph models as a methodological tool. The participants in the study were 1,279 students (678 boys and 601 girls) from nine junior middle schools in Shenzhen, China. The initial stage of the research used a peer nomination questionnaire and a subjective well-being scale (used in previous studies) to collect data on the peer relationship networks and the subjective well-being of the students. Exponential random graph models were then used to explore the relationships between students with the aim of clarifying the character of the peer relationship networks and the influence of peer relationships on subjective well being. The results showed that all the adolescent peer relationship networks in our investigation had positive reciprocal effects, positive transitivity effects and negative expansiveness effects. However, none of the relationship networks had obvious receiver effects or leaders. The adolescents in partial peer relationship networks presented similar levels of subjective well-being on three dimensions (satisfaction with life, positive affects and negative affects) though not all network friends presented these similarities. The study shows that peer networks can affect an individual's subjective well-being. However, whether similarities among adolescents are the result of social influences or social choices needs further exploration, including longitudinal studies that investigate the potential processes of subjective well-being similarities among adolescents.

Using Exponential Random Graph Models to Analyze the Character of Peer Relationship Networks and Their Effects on the Subjective Well-being of Adolescents

PubMed Central

Jiao, Can; Wang, Ting; Liu, Jianxin; Wu, Huanjie; Cui, Fang; Peng, Xiaozhe

2017-01-01

The influences of peer relationships on adolescent subjective well-being were investigated within the framework of social network analysis, using exponential random graph models as a methodological tool. The participants in the study were 1,279 students (678 boys and 601 girls) from nine junior middle schools in Shenzhen, China. The initial stage of the research used a peer nomination questionnaire and a subjective well-being scale (used in previous studies) to collect data on the peer relationship networks and the subjective well-being of the students. Exponential random graph models were then used to explore the relationships between students with the aim of clarifying the character of the peer relationship networks and the influence of peer relationships on subjective well being. The results showed that all the adolescent peer relationship networks in our investigation had positive reciprocal effects, positive transitivity effects and negative expansiveness effects. However, none of the relationship networks had obvious receiver effects or leaders. The adolescents in partial peer relationship networks presented similar levels of subjective well-being on three dimensions (satisfaction with life, positive affects and negative affects) though not all network friends presented these similarities. The study shows that peer networks can affect an individual’s subjective well-being. However, whether similarities among adolescents are the result of social influences or social choices needs further exploration, including longitudinal studies that investigate the potential processes of subjective well-being similarities among adolescents. PMID:28450845

Random Versus Blocked Practice to Enhance Mental Representation in Golf Putting.

PubMed

Fazeli, Davoud; Taheri, HamidReza; Saberi Kakhki, Alireza

2017-06-01

The purpose of this study was to investigate changes in mental representation from either random or blocked practice when engaged in golf putting. Thirty participants were randomly assigned to random practice, blocked practice, and no-practice groups. First, we measured novice golfers' initial mental representation levels and required them to perform 18 putting trials as a pre-test. We then asked random and blocked groups to practice in accordance with their group assignment for six consecutive days (10 blocks each day, 18 trials each). A week after the last practice session, we re-measured all participants' final mental representation levels and required them to perform 18 putting trials to evaluate learning retention through practice. While those engaged in the random practice method putted more poorly during acquisition (i.e., practice) than those in blocked practice, the random practice group experienced more accurate retention during the final putting trials, and they showed a more structured mental representation than those in blocked practice, one that was more similar to that of skilled golfers. These results support the acquisition of a rich mental representation through random versus blocked practice.

Random glucose is useful for individual prediction of type 2 diabetes: results of the Study of Health in Pomerania (SHIP).

PubMed

Kowall, Bernd; Rathmann, Wolfgang; Giani, Guido; Schipf, Sabine; Baumeister, Sebastian; Wallaschofski, Henri; Nauck, Matthias; Völzke, Henry

2013-04-01

Random glucose is widely used in routine clinical practice. We investigated whether this non-standardized glycemic measure is useful for individual diabetes prediction. The Study of Health in Pomerania (SHIP), a population-based cohort study in north-east Germany, included 3107 diabetes-free persons aged 31-81 years at baseline in 1997-2001. 2475 persons participated at 5-year follow-up and gave self-reports of incident diabetes. For the total sample and for subjects aged ≥50 years, statistical properties of prediction models with and without random glucose were compared. A basic model (including age, sex, diabetes of parents, hypertension and waist circumference) and a comprehensive model (additionally including various lifestyle variables and blood parameters, but not HbA1c) performed statistically significantly better after adding random glucose (e.g., the area under the receiver-operating curve (AROC) increased from 0.824 to 0.856 after adding random glucose to the comprehensive model in the total sample). Likewise, adding random glucose to prediction models which included HbA1c led to significant improvements of predictive ability (e.g., for subjects ≥50 years, AROC increased from 0.824 to 0.849 after adding random glucose to the comprehensive model+HbA1c). Random glucose is useful for individual diabetes prediction, and improves prediction models including HbA1c. Copyright © 2012 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

Diffusion in randomly perturbed dissipative dynamics

NASA Astrophysics Data System (ADS)

Rodrigues, Christian S.; Chechkin, Aleksei V.; de Moura, Alessandro P. S.; Grebogi, Celso; Klages, Rainer

2014-11-01

Dynamical systems having many coexisting attractors present interesting properties from both fundamental theoretical and modelling points of view. When such dynamics is under bounded random perturbations, the basins of attraction are no longer invariant and there is the possibility of transport among them. Here we introduce a basic theoretical setting which enables us to study this hopping process from the perspective of anomalous transport using the concept of a random dynamical system with holes. We apply it to a simple model by investigating the role of hyperbolicity for the transport among basins. We show numerically that our system exhibits non-Gaussian position distributions, power-law escape times, and subdiffusion. Our simulation results are reproduced consistently from stochastic continuous time random walk theory.

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.

A randomized controlled study of exposure therapy as aftercare for alcohol use disorder: study protocol.

PubMed

Mellentin, Angelina Isabella; Nielsen, Bent; Nielsen, Anette Søgaard; Yu, Fei; Stenager, Elsebeth

2016-04-21

It is well documented that individuals with Alcohol Use Disorder (AUD) respond well during evidence-based psychological treatment, but also that a large proportion relapses when discharged from treatment and confronted with alcohol in real life. Cue Exposure Treatment (CET) focuses on exposing individuals to alcohol cues in order to reduce cravings as well as the likelihood of relapse. The aims of the study are: 1) to investigate whether CET aftercare delivered via a smartphone or in group sessions increases the effect of Cognitive Behavioural Treatment in groups of alcohol dependent individuals; 2) to investigate whether CET as a smartphone application is as or more effective than CET group therapy, and 3) to investigate whether CET as a smartphone application is more cost-effective than CET group aftercare and Aftercare as Usual. The study will be implemented as an investigator-blinded randomized controlled trial. A total of 300 consecutively enrolled alcohol use disorder individuals recruited from an alcohol outpatient clinic will be randomized into one of the three following aftercare groups after concluding primary treatment: (1) CET as a smartphone application; (2) CET as group therapy, and (3) Aftercare as Usual. It is hypothesized that the two experimental groups will achieve better treatment outcomes compared to the control group (3). Individuals in the CET groups are given the opportunity to practise coping strategies during exposure to alcohol stimuli before being unavoidably confronted with alcohol and associated stimuli in real life. Thus, CET may help prevent patients from relapsing after concluding treatment, and in the long term. Moreover, the CET application has the potential to improve AUD treatment and continuing care by offering psychological treatment whenever and wherever the patient finds it convenient. ClinicalTrials.gov ID: NCT02298751 Registration date: 6 November 2014.

A video-based transdiagnostic REBT universal prevention program for internalizing problems in adolescents: study protocol of a cluster randomized controlled trial.

PubMed

Păsărelu, Costina Ruxandra; Dobrean, Anca

2018-04-13

Internalizing problems are the most prevalent mental health problems in adolescents. Transdiagnostic programs are promising manners to treat multiple problems within the same protocol, however, there is limited research regarding the efficacy of such programs delivered as universal prevention programs in school settings. Therefore, the present study aims to investigate the efficacy of a video-based transdiagnostic rational emotive behavioral therapy (REBT) universal prevention program, for internalizing problems. The second objective of the present paper will be to investigate the subsequent mechanisms of change, namely maladaptive cognitions. A two-arm parallel randomized controlled trial will be conducted, with two groups: a video-based transdiagnostic REBT universal prevention program and a wait list control. Power analysis indicated that the study will involve 338 participants. Adolescents with ages between 12 and 17 years old, from several middle schools and high schools, will be invited to participate. Assessments will be conducted at four time points: baseline (T 1 ), post-intervention (T 2 ), 3 months follow-up (T 3 ) and 12 months follow-up (T 4 ). Intent-to-treat analysis will be used in order to investigate significant differences between the two groups in both primary and secondary outcomes. This is the first randomized controlled trial that aims to investigate the efficacy and mechanisms of change of a video-based transdiagnostic REBT universal prevention program, delivered in a school context. The present study has important implications for developing efficient prevention programs, interactive, that will aim to target within the same protocol both anxiety and depressive symptoms. ClinicalTrials.gov: NCT02756507 . Registered on 25 April 2016.

Investigating methotrexate toxicity within a randomized double-blinded, placebo-controlled trial: Rationale and design of the Cardiovascular Inflammation Reduction Trial-Adverse Events (CIRT-AE) Study.

PubMed

Sparks, Jeffrey A; Barbhaiya, Medha; Karlson, Elizabeth W; Ritter, Susan Y; Raychaudhuri, Soumya; Corrigan, Cassandra C; Lu, Fengxin; Selhub, Jacob; Chasman, Daniel I; Paynter, Nina P; Ridker, Paul M; Solomon, Daniel H

2017-08-01

The role of low dose methotrexate (LDM) in potential serious toxicities remains unclear despite its common use. Prior observational studies investigating LDM toxicity compared LDM to other active drugs. Prior placebo-controlled clinical trials of LDM in inflammatory conditions were not large enough to investigate toxicity. The Cardiovascular Inflammation Reduction Trial (CIRT) is an ongoing NIH-funded, randomized, double-blind, placebo-controlled trial of LDM in the secondary prevention of cardiovascular disease. We describe here the rationale and design of the CIRT-Adverse Events (CIRT-AE) ancillary study which aims to investigate adverse events within CIRT. CIRT will randomize up to 7000 participants with cardiovascular disease and no systemic rheumatic disease to either LDM (target dose: 15-20mg/week) or placebo for an average follow-up period of 3-5 years; subjects in both treatment arms receive folic acid 1mg daily for 6 days each week. The primary endpoints of CIRT include recurrent cardio vascular events, incident diabetes, and all-cause mortality, and the ancillary CIRT-AE study has been designed to adjudicate other clinically important adverse events including hepatic, gastrointestinal, respiratory, hematologic, infectious, mucocutaneous, oncologic, renal, neurologic, and musculoskeletal outcomes. Methotrexate polyglutamate levels and genome-wide single nucleotide polymorphisms will be examined for association with adverse events. CIRT-AE will comprehensively evaluate potential LDM toxicities among subjects with cardiovascular disease within the context of a large, ongoing, double-blind, placebo-controlled trial. This information may lead to a personalized approach to monitoring LDM in clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Whole Grain Wheat Bread on Visceral Fat Obesity in Japanese Subjects: A Randomized Double-Blind Study.

PubMed

Kikuchi, Yosuke; Nozaki, Satomi; Makita, Miki; Yokozuka, Shoji; Fukudome, Shin-Ichi; Yanagisawa, Takashi; Aoe, Seiichiro

2018-04-18

Metabolic syndrome is a risk factor for cardiovascular diseases and has become increasingly common in Japan. Epidemiological studies show inverse associations between intake of whole wheat grains and metabolic syndrome, but few dietary intervention trials have investigated the effect of whole wheat grain consumption. It was investigated whether a diet in which refined wheat bread (RW diet) was substituted by whole grain wheat bread (WW diet) would reduce visceral fat obesity in Japanese subjects. A randomized double-blind placebo-controlled intervention study was conducted in 50 Japanese subjects with body mass index (BMI) ≥ 23 kg/m 2 . Subjects were randomly assigned WW (WW group) or RW diets (RW group) for 12 weeks. Blood samples and computed tomography scans were obtained every 6th week. The WW group showed decrease (-4 cm 2 ) in visceral fat area (VFA) (p < 0.05), whereas the RW group showed no significant changes. These time-dependent changes were significantly different between the groups. WW diet led to significant and safe reductions in VFA in subjects with BMI ≥ 23 kg/m 2 . WW diet may contribute to preventing visceral fat obesity.

Associating a product with a luxury brand label modulates neural reward processing and favors choices in materialistic individuals.

PubMed

Audrin, Catherine; Ceravolo, Leonardo; Chanal, Julien; Brosch, Tobias; Sander, David

2017-11-23

The present study investigated the extent to which luxury vs. non-luxury brand labels (i.e., extrinsic cues) randomly assigned to items and preferences for these items impact choice, and how this impact may be moderated by materialistic tendencies (i.e., individual characteristics). The main objective was to investigate the neural correlates of abovementioned effects using functional magnetic resonance imaging. Behavioural results showed that the more materialistic people are, the more they choose and like items labelled with luxury brands. Neuroimaging results revealed the implication of a neural network including the dorsolateral and ventromedial prefrontal cortex and the orbitofrontal cortex that was modulated by the brand label and also by the participants' preference. Most importantly, items with randomly assigned luxurious brand labels were preferentially chosen by participants and triggered enhanced signal in the caudate nucleus. This effect increased linearly with materialistic tendencies. Our results highlight the impact of brand-item association, although random in our study, and materialism on preference, relying on subparts of the brain valuation system for the integration of extrinsic cues, preferences and individual characteristics.

A randomized, double-blind, placebo controlled, parallel group, efficacy study of alpha BRAIN® administered orally.

PubMed

Solomon, Todd M; Leech, Jarrett; deBros, Guy B; Murphy, Cynthia A; Budson, Andrew E; Vassey, Elizabeth A; Solomon, Paul R

2016-03-01

Alpha BRAIN® is a nootropic supplement that purports to enhance cognitive functioning in healthy adults. The goal of this study was to investigate the efficacy of this self-described cognitive enhancing nootropic on cognitive functioning in a group of healthy adults by utilizing a randomized, double blind, placebo-controlled design. A total of 63-treatment naïve individuals between 18 and 35 years of age completed the randomized, double-blind, placebo controlled trial. All participants completed a 2-week placebo run in before receiving active product, Alpha BRAIN® or new placebo, for 6 weeks. Participants undertook a battery of neuropsychological tests at randomization and at study completion. Primary outcome measures included a battery of neuropsychological tests and measures of sleep. Compared with placebo, Alpha BRAIN® significantly improved on tasks of delayed verbal recall and executive functioning. Results also indicated significant time-by-group interaction in delayed verbal recall for the Alpha BRAIN® group. The use of Alpha BRAIN® for 6 weeks significantly improved recent verbal memory when compared with controls, in a group of healthy adults. While the outcome of the study is encouraging, this is the first randomized controlled trial of Alpha BRAIN®, and the results merit further study. Copyright © 2016 John Wiley & Sons, Ltd.

The Relationship Between Statins and Prostate Cancer Prevention

DTIC Science & Technology

2009-09-01

incidence and progression. 2007-2009 Testosterone Supplementation for Men with Sarcopenia NIH, U01AGO14369/CFDA Site-PI, $100,000 This randomized...controlled clinical trail is designed to investigate whether testosterone gel can increase muscle strength among men with sarcopenia and low...Healthcare System. This study is investigating the utility of testosterone in older men with sarcopenia . I am also the local principal investigator

Applying Generalizability Theory To Evaluate Treatment Effect in Single-Subject Research.

ERIC Educational Resources Information Center

Lefebvre, Daniel J.; Suen, Hoi K.

An empirical investigation of methodological issues associated with evaluating treatment effect in single-subject research (SSR) designs is presented. This investigation: (1) conducted a generalizability (G) study to identify the sources of systematic and random measurement error (SRME); (2) used an analytic approach based on G theory to integrate…

Laboratory and field investigations of wave attenuation by live marsh vegetation

USDA-ARS?s Scientific Manuscript database

Wave attenuation by live marsh vegetation was investigated experimentally in this study. Laboratory experiments were conducted in a 20.6 m long, 0.69 m wide and 1.22 m deep wave flume under regular and random waves. The vegetation species used are Spartina alterniflora and Juncus roemerianus, which ...

Efficacy of an Electronic Editing Strategy with College Students with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Woods-Groves, Suzanne; Hua, Youjia; Ford, Jeremy W.; Neil, Katelyn M.

2017-01-01

In this study we investigated an editing strategy to develop effective proofreading skills (i.e., mechanics and substantive revisions) within electronic texts through an experimental pre- and posttest group design with random assignment. Fifteen college students with intellectual and developmental disabilities participated in this investigation.…

Effects of Self-Control, Social Control, and Social Learning on Sexting Behavior among South Korean Youths

ERIC Educational Resources Information Center

Lee, Chang-Hun; Moak, Stacy; Walker, Jeffery T.

2016-01-01

Despite the emerging phenomenon of sexting, scientific investigation with criminological perspectives has been limited. Utilizing data collected from 1,612 randomly selected youth in South Korea, this study begins the investigation into which criminological theory best explains sexting behaviors. Theories considered include self-control, social…

An Investigation on Secondary School Students' Attitude towards Science in Ogun State, Nigeria

ERIC Educational Resources Information Center

Sakariyau, A. O.; Taiwo, Michael O.; Ajagbe, Olalere W.

2016-01-01

The study investigated the attitudes of secondary school students towards science in Odeda Local Government Area of Ogun State, Nigeria. Two hundred senior secondary school students consisting of 84 males and 116 females were selected from five secondary schools using stratified random sampling techniques. A 20-item Attitude to Science…

A double-blind randomized discontinuation phase II study of sorafenib (BAY 43-9006) in previously treated non-small cell lung cancer patients: Eastern Cooperative Oncology Group study E2501

PubMed Central

Wakelee, Heather A.; Lee, Ju-Whei; Hanna, Nasser H.; Traynor, Anne M.; Carbone, David P.; Schiller, Joan H.

2012-01-01

Introduction Sorafenib is a raf kinase and angiogenesis inhibitor with activity in multiple cancers. This phase II study in heavily pretreated non-small cell lung cancer (NSCLC) patients (≥ two prior therapies) utilized a randomized discontinuation design. Methods Patients received 400 mg of sorafenib orally twice daily for two cycles (two months) (Step 1). Responding patients on Step 1 continued on sorafenib; progressing patients went off study, and patients with stable disease were randomized to placebo or sorafenib (Step 2), with crossover from placebo allowed upon progression. The primary endpoint of this study was the proportion of patients having stable or responding disease two months after randomization. Results : There were 299 patients evaluated for Step 1 with 81 eligible patients randomized on Step 2 who received sorafenib (n=50) or placebo (n=31). The two-month disease control rates following randomization were 54% and 23% for patients initially receiving sorafenib and placebo respectively, p=0.005. The hazard ratio for progression on Step 2 was 0.51 (95% CI 0.30, 0.87, p=0.014) favoring sorafenib. A trend in favor of overall survival with sorafenib was also observed (13.7 versus 9.0 months from time of randomization), HR 0.67 (95% CI 0.40-1.11), p=0.117. A dispensing error occurred which resulted in unblinding of some patients, but not before completion of the 8 week initial step 2 therapy. Toxicities were manageable and as expected. Conclusions : The results of this randomized discontinuation trial suggest that sorafenib has single agent activity in a heavily pretreated, enriched patient population with advanced NSCLC. These results support further investigation with sorafenib as a single agent in larger, randomized studies in NSCLC. PMID:22982658

Does the Well-Being of Individuals with Down Syndrome and Dementia Improve When Using Life Story Books and Rummage Boxes? A Randomized Single Case Series Experiment

ERIC Educational Resources Information Center

Crook, Nicola; Adams, Malcolm; Shorten, Nicola; Langdon, Peter E.

2016-01-01

Background: This study investigated whether a personalized life story book and rummage box enhanced well-being and led to changes in behaviour for people with Down syndrome (DS) who have dementia. Materials and Methods: A randomized single case series design was used with five participants who had DS and a diagnosis of dementia. Participants were…

An Empirical Comparison of Methods for Equating with Randomly Equivalent Groups of 50 to 400 Test Takers. Research Report. ETS RR-10-05

ERIC Educational Resources Information Center

Livingston, Samuel A.; Kim, Sooyeon

2010-01-01

A series of resampling studies investigated the accuracy of equating by four different methods in a random groups equating design with samples of 400, 200, 100, and 50 test takers taking each form. Six pairs of forms were constructed. Each pair was constructed by assigning items from an existing test taken by 9,000 or more test takers. The…

High intensity acoustic tests of a thermally stressed aluminum plate in TAFA

NASA Technical Reports Server (NTRS)

Ng, Chung Fai; Clevenson, Sherman A.

1989-01-01

An investigation was conducted in the Thermal Acoustic Fatigue Apparatus at the Langley Research Center to study the acoustically excited random motion of an aluminum plate which is buckled due to thermal stresses. The thermal buckling displacements were measured and compared with theory. The general trends of the changes in resonances frequencies and random responses of the plate agree with previous theoretical prediction and experimental results for a mechanically buckled plate.

Mediating Effects of Home-Related Factors on Fat Intake from Snacks in a School-Based Nutrition Intervention among Adolescents

ERIC Educational Resources Information Center

Van Lippevelde, Wendy; van Stralen, Maartje; Verloigne, Maite; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Brug, Johannes; Maes, Lea; Haerens, Leen

2012-01-01

The purpose of the present study was to investigate if the effects of the parental component of a school-based intervention on dietary fat intake from snacking were mediated by changes in home-related factors. A random sample of 10 schools with 2232 pupils aged 11-15 years was randomly assigned to one of two intervention groups [one with (n =…

Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

PubMed

Crampin, A C; Mwinuka, V; Malema, S S; Glynn, J R; Fine, P E

2001-01-01

Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density. We also present an audit of the selection process, and discuss the potential of this method in other settings.

Recruitment and accrual of women in a placebo-controlled clinical pilot study on manual therapy.

PubMed

Cambron, Jerrilyn A; Hawk, Cheryl; Evans, Roni; Long, Cynthia R

2004-06-01

To investigate the accrual rates and recruitment processes among 3 Midwestern sites during a pilot study on manual therapy for chronic pelvic pain. Multisite pilot study for a randomized, placebo-controlled clinical trial. Three chiropractic institutions in or near major metropolitan cities in the Midwestern United States. Thirty-nine women aged 18 to 45 with chronic pelvic pain of at least 6 months duration, diagnosed by a board certified gynecologist. The method of recruitment was collected for each individual who responded to an advertisement and completed an interviewer-administered telephone screen. Participants who were willing and eligible after 3 baseline visits were entered into a randomized clinical trial. The number of responses and accrual rates were determined for the overall study, each of the 3 treatment sites, and each of the 5 recruitment efforts. In this study, 355 women were screened over the telephone and 39 were randomized, making the rate of randomization approximately 10%. The most effective recruitment methods leading to randomization were direct mail (38%) and radio advertisements (34%). However, success of the recruitment process differed by site. Based on the accrual of this multisite pilot study, a full-scale trial would not be feasible using this study's parameters. However, useful information was gained on recruitment effectiveness, eligibility criteria, and screening protocols among the 3 metropolitan sites.

Relationship between Study Habits and Test Anxiety of Higher Secondary Students

ERIC Educational Resources Information Center

Lawrence, Arul A. S.

2014-01-01

The present study aims to probe the relationship between study habits and test anxiety of higher secondary students. In this normative study survey method was employed. The population for the present study consisted of higher secondary students studying in Tirunelveli district. The investigator used the simple random sampling technique. The sample…

Undermining position effects in choices from arrays, with implications for police lineups.

PubMed

Palmer, Matthew A; Sauer, James D; Holt, Glenys A

2017-03-01

Choices from arrays are often characterized by position effects, such as edge-aversion. We investigated position effects when participants attempted to pick a suspect from an array similar to a police photo lineup. A reanalysis of data from 2 large-scale field studies showed that choices made under realistic conditions-closely matching eyewitness identification decisions in police investigations-displayed edge-aversion and bias to choose from the top row (Study 1). In a series of experiments (Studies 2a-2c and 3), participants guessing the location of a suspect exhibited edge-aversion regardless of whether the lineup was constructed to maximize the chances of the suspect being picked, to ensure the suspect did not stand out, or randomly. Participants favored top locations only when the lineup was constructed to maximize the chances of the suspect being picked. In Studies 4 and 5, position effects disappeared when (a) response options were presented in an array with no obvious center, edges, or corners, and (b) instructions stated that the suspect was placed randomly. These findings show that position effects are influenced by a combination of task instructions and array shape. Randomizing the location of the suspect and modifying the shape of the lineup array may reduce misidentification. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Effects of defibrotide in patients with chronic deep insufficiency. The PROVEDIS study.

PubMed

Coccheri, S; Andreozzi, G M; D'Addato, M; Gensini, G F

2004-06-01

In the present study the effect of defibrotide, an antithrombotic and profibrinolytic agent, was investigated in patients with chronic venous insufficiency (CVI) due to deep vein obstruction and/or reflux (chronic deep vein insufficiency, CDVI). The study was a multicenter, randomized, double blind placebo controlled trial in which only patients with CDVI confirmed by ultrasound were enrolled. All patients were treated with adequate elastic compression and randomized to receive either oral defibrotide (800 mg/die) or matching placebo for 1 year. Patients with active or previous leg ulcer were excluded. A total of 288 patients were randomized and 159 completed the study. At baseline ultrasound investigation, obstructive changes were found in 2/3 of all patients thus ascertaining a post-thrombotic syndrome (PTS). The primary endpoint, ankle circumference, was significantly reduced under defibrotide from day 120 throughout 360. Scores for pain and edema were improved. The number of episodes of superficial thrombophlebitis and deep vein thrombosis was significantly lower under defibrotide (n=2) than under placebo (n=10). The majority of these events occurred in the subset of patients with documented PTS. Treatment with defibrotide in addition to elastic compression in patients with objectively assessed CDVI, mostly due to PTS, resulted in clinical benefits and prevented thrombotic complications harmful to the limb conditions.

Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA): safety and efficacy of low-dose prostacyclin administration and blood pressure target in addition to standard therapy, as compared to standard therapy alone, in post-cardiac arrest syndrome patients: study protocol for a randomized controlled trial.

PubMed

Meyer, Anna Sina P; Ostrowski, Sisse R; Kjaergaard, Jesper; Johansson, Pär I; Hassager, Christian

2016-08-02

Morbidity and mortality following initial survival of cardiac arrest remain high despite great efforts to improve resuscitation techniques and post-resuscitation care, in part due to the ischemia-reperfusion injury secondary to the restoration of the blood circulation. Patients resuscitated from cardiac arrest display evidence of endothelial injury and coagulopathy (hypocoagulability, hyperfibrinolysis), which in associated with poor outcome. Recent randomized controlled trials have revealed that treatment with infusion of prostacyclin reduces endothelial damage after major surgery and AMI. Thus, a study is pertinent to investigate if prostacyclin infusion as a therapeutic intervention reduces endothelial damage without compromising, or even improving, the hemostatic competence in resuscitated cardiac arrest patients. Post-cardiac arrest patients frequently have a need for vasopressor therapy (catecholamines) to achieve the guideline-supported blood pressure goals. To evaluate a possible catecholamine interaction with the primary endpoints of this study, included patients will be randomized into two different blood pressure goals within guideline-recommended targets. A randomized, placebo-controlled, double-blind investigator-initiated pilot trial in 40 out-of-hospital-cardiac-arrest (OHCA) patients will be conducted. Patients will be randomly assigned to either the active treatment group (48 hours of active study drug (iloprost, 1 ng/kg/min) or to the control group [placebo (saline) infusion]. Target mean blood pressure levels will be allocated 1:1 to 65 mmHg or approximately 75 mmHg, which gives four different permutations, namely: (i) iloprost/65 mHg, (ii) iloprost/75 mmHg, (iii) placebo/65 mmHg, and (iv) placebo/75 mmHg. All randomized patients will be treated in accordance with state-of-the art therapy including targeted temperature management. The primary endpoint of this study is change in biomarkers indicative of endothelial activation and damage, [soluble thrombomodulin (sTM), sE-selectin, syndecan-1, soluble vascular endothelial growth factor (sVEGF), nucleosomes] and sympathoadrenal over activation (epinephrine/norepinephrine) from baseline to 48 hours post-randomization. The secondary endpoints of this trial will include: (1) the hemostatic profile [change in functional hemostatic blood test (thrombelastography (TEG) and whole blood platelet aggregometry (multiplate)) blood cell and endothelial cell-derived microparticles]; (2) feasibility of blood pressure target intervention (target 90 %); (3) interaction of primary endpoints and blood pressure target; (4) levels of neuron-specific enolase at 48 hours post-inclusion according to blood pressure targets. The ENDO-RCA study is a pilot study trial that investigates safety and efficacy of low-dose infusion of prostacyclin administration as compared to standard therapy in post-cardiac arrest syndrome patients. Trial registration at ClinicalTrials.gov (identifier NCT02685618 ) on 18 February 2016.

Heated Ultrasound Gel and Patient Satisfaction with Bedside Ultrasound Studies: The HUGS Trial

PubMed Central

Krainin, Benjamin M.; Thaut, Lane C.; April, Michael D.; Curtis, Ryan A.; Kaelin, Andrea L.; Hardy, Garrett B.; Weymouth, Wells L.; Srichandra, Jonathan; Chin, Eric J.; Summers, Shane M.

2017-01-01

Introduction Our goal was to determine if heated gel for emergency department (ED) bedside ultrasonography improves patient satisfaction compared to room-temperature gel. Methods We randomized a convenience sample of ED patients determined by their treating physician to require a bedside ultrasound (US) study to either heated gel (102.0° F) or room-temperature gel (82.3° F). Investigators performed all US examinations. We informed all subjects that the study entailed investigation into various measures to improve patient satisfaction with ED US examinations but did not inform them of our specific focus on gel temperature. Investigators wore heat-resistant gloves while performing the examinations to blind themselves to the gel temperature. After completion of the US, subjects completed a survey including the primary outcome measure of patient satisfaction as measured on a 100-mm visual analogue scale (VAS). A secondary outcome was patient perceptions of sonographer professionalism measured by an ordinal scale (1–5). Results We enrolled 124 subjects; 120 completed all outcome measures. Of these, 59 underwent randomization to US studies with room-temperature gel and 61 underwent randomization to heated US gel. Patient 100-mm VAS satisfaction scores were 83.9 among patients undergoing studies with room-temperature gel versus 87.6 among subjects undergoing studies with heated gel (effect size 3.7, 95% confidence interval −1.3–8.6). There were similarly no differences between the two arms with regard to patient perceptions of sonographer professionalism. Conclusion The use of heated ultrasound gel appears to have no material impact on the satisfaction of ED patients undergoing bedside ultrasound studies. PMID:29085538

Executive function in adults with attention-deficit/hyperactivity disorder during treatment with atomoxetine in a randomized, placebo-controlled, withdrawal study.

PubMed

Adler, Lenard; Tanaka, Yoko; Williams, David; Trzepacz, Paula T; Goto, Taro; Allen, Albert J; Escobar, Rodrigo; Upadhyaya, Himanshu P

2014-08-01

We assessed the executive function in adults with attention-deficit/hyperactivity disorder (ADHD) during atomoxetine treatment in a randomized withdrawal trial. Responders (Conners' ADHD Rating Scale-Investigator Rated: Screening Version [adult prompts] ≥30% reduction from baseline and Clinical Global Impression Scale-ADHD Severity score ≤3) to open-label atomoxetine (40-100 mg/d, 12 weeks) entered a 37-week double-blind maintenance period. Patients who maintained response (double-blind atomoxetine for 12 weeks) were randomized 1:1 to atomoxetine (80-100 mg/d, n = 266) or placebo (n = 258) for 25 weeks (total duration, 1 year). Patients and investigators were blinded to response criteria and randomization timing. Change in executive function was assessed with the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) Self-Report and Informant T scores from the randomization to the last-observation-carried-forward postrandomization week 25 (after week 17). Of the enrolled patients (n = 2017; mean age, 33.2 years; male, 58.7%), 524 responders were randomized. During open-label atomoxetine, subscales and individual items on both BRIEF-A questionnaires showed significant improvement (P < 0.001). After randomization, the following T scores improved significantly (P ≤ 0.05) with patients in the atomoxetine group versus those in the placebo group: global executive composite, behavioral regulation, and metacognition indices; plan/organize, working memory, inhibit, task monitor and shift (both BRIEF-A questionnaires), emotional control and organization of materials (BRIEF-A Informant), and initiate (BRIEF-A Self-Report). Atomoxetine significantly improved the executive function compared with placebo, which was maintained for 25 weeks or more; the executive function of patients in the placebo group worsened but did not return to baseline levels after randomization.

Interventions for reducing fear of childbirth: A systematic review and meta-analysis of clinical trials.

PubMed

MoghaddamHosseini, Vahideh; Nazarzadeh, Milad; Jahanfar, Shayesteh

2017-11-07

Fear of childbirth is a problematic mental health issue during pregnancy. But, effective interventions to reduce this problem are not well understood. To examine effective interventions for reducing fear of childbirth. The Cochrane Central Register of Controlled Trials, PubMed, Embase and PsycINFO were searched since inception till September 2017 without any restriction. Randomised controlled trials and quasi-randomised controlled trials comparing interventions for treatment of fear of childbirth were included. The standardized mean differences were pooled using random and fixed effect models. The heterogeneity was determined using the Cochran's test and I 2 index and was further explored in meta-regression model and subgroup analyses. Ten studies inclusive of 3984 participants were included in the meta-analysis (2 quasi-randomized and 8 randomized clinical trials). Eight studies investigated education and two studies investigated hypnosis-based intervention. The pooled standardized mean differences of fear for the education intervention and hypnosis group in comparison with control group were -0.46 (95% CI -0.73 to -0.19) and -0.22 (95% CI -0.34 to -0.10), respectively. Both types of interventions were effective in reducing fear of childbirth; however our pooled results revealed that educational interventions may reduce fear with double the effect of hypnosis. Further large scale randomized clinical trials and individual patient data meta-analysis are warranted for assessing the association. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Guidance and examination by ultrasound versus landmark and radiographic method for placement of subclavian central venous catheters: study protocol for a randomized controlled trial

PubMed Central

2014-01-01

Background Central venous catheters play an important role in patient care. Real-time ultrasound-guided subclavian central venous (SCV) cannulation may reduce the incidence of complications and the time between skin penetration and the aspiration of venous blood into the syringe. Ultrasonic diagnosis of catheter misplacement and pneumothorax related to central venous catheterization is rapid and accurate. It is unclear, however, whether ultrasound real-time guidance and examination can reduce procedure times and complication rates when compared with landmark guidance and radiographic examination for SCV catheterization. Methods/Design The Subclavian Central Venous Catheters Guidance and Examination by UltraSound (SUBGEUS) study is an investigator-initiated single center, randomized, controlled two-arm trial. Three hundred patients undergoing SCV catheter placement will be randomized to ultrasound real-time guidance and examination or landmark guidance and radiographic examination. The primary outcome is the time between the beginning of the procedure and control of the catheter. Secondary outcomes include the times required for the six components of the total procedure, the occurrence of complications (pneumothorax, hemothorax, or misplacement), failure of the technique and occurrence of central venous catheter infections. Discussion The SUBGEUS trial is the first randomized controlled study to investigate whether ultrasound real-time guidance and examination for SCV catheter placement reduces all procedure times and the rate of complications. Trial registration ClinicalTrials.gov Identifier: NCT01888094 PMID:24885789

The Efficacy of Acupressure for Symptom Management: A Systematic Review

PubMed Central

Lee, Eun Jin; Frazier, Susan

2011-01-01

Context Acupressure is a non-invasive strategy used to manage various symptoms. Objectives The purpose of this paper was to review randomized controlled trials (RCTs) that investigated the efficacy of acupressure for the management of symptoms. Methods A literature search was conducted in the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Medline, and PubMed, using the key words acupressure, clinical trial, human, and/or randomized. RCTs published between January 1, 2000 and January 31, 2010, which used acupressure as an intervention for one group, were included when they were written in English and when there were four or more studies of the efficacy of acupressure for that particular symptom. Results Forty-three studies were included in this review. Investigators in 16 of 23 studies concluded acupressure was effective, primarily for the management of nausea and vomiting in patients during pregnancy and during chemotherapy. Investigators in nine of ten studies concluded that acupressure was effective for pain in patients with dysmenorrhea, during labor, and after trauma. Investigators of four studies concluded that acupressure was effective in the management of dyspnea and investigators in six studies concluded that acupressure was effective in improving fatigue and reducing insomnia in a variety of populations. However, evaluation of the RCT reports indicated a significant likelihood of bias. Conclusion Acupressure may be a useful strategy for the management of multiple symptoms in a variety of patient populations, but rigorous trials are needed. Inclusion of acupressure as an intervention may improve patient outcomes. PMID:21531533

Feasibility of quasi-random band model in evaluating atmospheric radiance

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Mirakhur, N.

1980-01-01

The use of the quasi-random band model in evaluating upwelling atmospheric radiation is investigated. The spectral transmittance and total band adsorptance are evaluated for selected molecular bands by using the line by line model, quasi-random band model, exponential sum fit method, and empirical correlations, and these are compared with the available experimental results. The atmospheric transmittance and upwelling radiance were calculated by using the line by line and quasi random band models and were compared with the results of an existing program called LOWTRAN. The results obtained by the exponential sum fit and empirical relations were not in good agreement with experimental results and their use cannot be justified for atmospheric studies. The line by line model was found to be the best model for atmospheric applications, but it is not practical because of high computational costs. The results of the quasi random band model compare well with the line by line and experimental results. The use of the quasi random band model is recommended for evaluation of the atmospheric radiation.

A Study Investigating the Effect of Treatment Developed by Integrating the 5E and Simulation on Pre-Service Science Teachers' Achievement in Photoelectric Effect

ERIC Educational Resources Information Center

Taslidere, Erdal

2015-01-01

The Current study investigated the effect of the 5E learning cycle in which the simulations were integrated on pre-service science teachers' achievement in photoelectric subject. Four sophomore level classes with their 140 students participated in the research and a quasi-experimental design was used. The classes were randomly assigned into one of…

PRELIMINARY REPORT ON NATIONWIDE STUDY OF DRINKING WATER AND CARDIOVASCULAR DISEASES

EPA Science Inventory

This study was designed to further investigate the association(s) of cardiovascular diseases and drinking water constituents. A sample of 4200 adults were randomly selected from 35 geographic areas to represent the civilian noninstitutionalized population of the contiguous United...

Urine sampling techniques in symptomatic primary-care patients: a diagnostic accuracy review.

PubMed

Holm, Anne; Aabenhus, Rune

2016-06-08

Choice of urine sampling technique in urinary tract infection may impact diagnostic accuracy and thus lead to possible over- or undertreatment. Currently no evidencebased consensus exists regarding correct sampling technique of urine from women with symptoms of urinary tract infection in primary care. The aim of this study was to determine the accuracy of urine culture from different sampling-techniques in symptomatic non-pregnant women in primary care. A systematic review was conducted by searching Medline and Embase for clinical studies conducted in primary care using a randomized or paired design to compare the result of urine culture obtained with two or more collection techniques in adult, female, non-pregnant patients with symptoms of urinary tract infection. We evaluated quality of the studies and compared accuracy based on dichotomized outcomes. We included seven studies investigating urine sampling technique in 1062 symptomatic patients in primary care. Mid-stream-clean-catch had a positive predictive value of 0.79 to 0.95 and a negative predictive value close to 1 compared to sterile techniques. Two randomized controlled trials found no difference in infection rate between mid-stream-clean-catch, mid-stream-urine and random samples. At present, no evidence suggests that sampling technique affects the accuracy of the microbiological diagnosis in non-pregnant women with symptoms of urinary tract infection in primary care. However, the evidence presented is in-direct and the difference between mid-stream-clean-catch, mid-stream-urine and random samples remains to be investigated in a paired design to verify the present findings.

A systematic review of Investigator Global Assessment (IGA) in atopic dermatitis (AD) trials: Many options, no standards.

PubMed

Futamura, Masaki; Leshem, Yael A; Thomas, Kim S; Nankervis, Helen; Williams, Hywel C; Simpson, Eric L

2016-02-01

Investigators often use global assessments to provide a snapshot of overall disease severity in dermatologic clinical trials. Although easy to perform, the frequency of use and standardization of global assessments in studies of atopic dermatitis (AD) is unclear. We sought to assess the frequency, definitions, and methods of analysis of Investigator Global Assessment in randomized controlled trials of AD. We conducted a systematic review using all published randomized controlled trials of AD treatments in the Global Resource of Eczema Trials database (2000-2014). We determined the frequency of global scales application and defining features. Among 317 trials identified, 101 trials (32%) used an investigator-performed global assessment as an outcome measure. There was large variability in global assessments between studies in nomenclature, scale size, definitions, outcome description, and analysis. Both static and dynamic scales were identified that ranged from 4- to 7-point scales. North American studies used global assessments more commonly than studies from other countries. The search was restricted to the Global Resource of Eczema Trials database. Global assessments are used frequently in studies of AD, but their complete lack of standardized definitions and implementation preclude any meaningful comparisons between studies, which in turn impedes data synthesis to inform clinical decision-making. Standardization is urgently required. Copyright © 2015. Published by Elsevier Inc.

Micro-Randomized Trials: An Experimental Design for Developing Just-in-Time Adaptive Interventions

PubMed Central

Klasnja, Predrag; Hekler, Eric B.; Shiffman, Saul; Boruvka, Audrey; Almirall, Daniel; Tewari, Ambuj; Murphy, Susan A.

2015-01-01

Objective This paper presents an experimental design, the micro-randomized trial, developed to support optimization of just-in-time adaptive interventions (JITAIs). JITAIs are mHealth technologies that aim to deliver the right intervention components at the right times and locations to optimally support individuals’ health behaviors. Micro-randomized trials offer a way to optimize such interventions by enabling modeling of causal effects and time-varying effect moderation for individual intervention components within a JITAI. Methods The paper describes the micro-randomized trial design, enumerates research questions that this experimental design can help answer, and provides an overview of the data analyses that can be used to assess the causal effects of studied intervention components and investigate time-varying moderation of those effects. Results Micro-randomized trials enable causal modeling of proximal effects of the randomized intervention components and assessment of time-varying moderation of those effects. Conclusions Micro-randomized trials can help researchers understand whether their interventions are having intended effects, when and for whom they are effective, and what factors moderate the interventions’ effects, enabling creation of more effective JITAIs. PMID:26651463

Block versus Random Amphiphilic Glycopolymer Nanopaticles as Glucose-Responsive Vehicles.

PubMed

Guo, Qianqian; Zhang, Tianqi; An, Jinxia; Wu, Zhongming; Zhao, Yu; Dai, Xiaomei; Zhang, Xinge; Li, Chaoxing

2015-10-12

To explore the effect of polymer structure on their self-assembled aggregates and their unique characteristics, this study was devoted to developing a series of amphiphilic block and random phenylboronic acid-based glycopolymers by RAFT polymerization. The amphiphilic glycopolymers were successfully self-assembled into spherically shaped nanoparticles with narrow size distribution in aqueous solution. For block and random copolymers with similar monomer compositions, block copolymer nanoparticles exhibited a more regular transmittance change with the increasing glucose level, while a more evident variation of size and quicker decreasing tendency in I/I0 behavior in different glucose media were observed for random copolymer nanoparticles. Cell viability of all the polymer nanoparticles investigated by MTT assay was higher than 80%, indicating that both block and random copolymers had good cytocompatibility. Insulin could be encapsulated into both nanoparticles, and insulin release rate for random glycopolymer was slightly quicker than that for the block ones. We speculate that different chain conformations between block and random glycopolymers play an important role in self-assembled nanoaggregates and underlying glucose-sensitive behavior.

Random mechanics: Nonlinear vibrations, turbulences, seisms, swells, fatigue

NASA Astrophysics Data System (ADS)

Kree, P.; Soize, C.

The random modeling of physical phenomena, together with probabilistic methods for the numerical calculation of random mechanical forces, are analytically explored. Attention is given to theoretical examinations such as probabilistic concepts, linear filtering techniques, and trajectory statistics. Applications of the methods to structures experiencing atmospheric turbulence, the quantification of turbulence, and the dynamic responses of the structures are considered. A probabilistic approach is taken to study the effects of earthquakes on structures and to the forces exerted by ocean waves on marine structures. Theoretical analyses by means of vector spaces and stochastic modeling are reviewed, as are Markovian formulations of Gaussian processes and the definition of stochastic differential equations. Finally, random vibrations with a variable number of links and linear oscillators undergoing the square of Gaussian processes are investigated.

A Qualitative Study on Sustainable Professional Learning Communities in Catholic Elementary Schools

ERIC Educational Resources Information Center

Fernandez, Alexandra

2017-01-01

This qualitative study examined the elements of professional learning communities within Catholic elementary schools. The purpose of this study was to investigate best practices of Professional Learning Communities (PLCs) as reported by elementary principals in a random sample of Catholic elementary schools. The researcher interviewed 14…

Testing the Efficacy of a Tier 2 Mathematics Intervention: A Conceptual Replication Study

ERIC Educational Resources Information Center

Doabler, Christian T.; Clarke, Ben; Kosty, Derek B.; Kurtz-Nelson, Evangeline; Fien, Hank; Smolkowski, Keith; Baker, Scott K.

2016-01-01

The purpose of this closely aligned conceptual replication study was to investigate the efficacy of a Tier 2 kindergarten mathematics intervention. The replication study differed from the initial randomized controlled trial on three important elements: geographical region, timing of the intervention, and instructional context of the…

Lifshits Tails for Randomly Twisted Quantum Waveguides

NASA Astrophysics Data System (ADS)

Kirsch, Werner; Krejčiřík, David; Raikov, Georgi

2018-03-01

We consider the Dirichlet Laplacian H_γ on a 3D twisted waveguide with random Anderson-type twisting γ . We introduce the integrated density of states N_γ for the operator H_γ , and investigate the Lifshits tails of N_γ , i.e. the asymptotic behavior of N_γ (E) as E \\downarrow \\inf supp dN_γ . In particular, we study the dependence of the Lifshits exponent on the decay rate of the single-site twisting at infinity.

Cooperation and charity in spatial public goods game under different strategy update rules

NASA Astrophysics Data System (ADS)

Li, Yixiao; Jin, Xiaogang; Su, Xianchuang; Kong, Fansheng; Peng, Chengbin

2010-03-01

Human cooperation can be influenced by other human behaviors and recent years have witnessed the flourishing of studying the coevolution of cooperation and punishment, yet the common behavior of charity is seldom considered in game-theoretical models. In this article, we investigate the coevolution of altruistic cooperation and egalitarian charity in spatial public goods game, by considering charity as the behavior of reducing inter-individual payoff differences. Our model is that, in each generation of the evolution, individuals play games first and accumulate payoff benefits, and then each egalitarian makes a charity donation by payoff transfer in its neighborhood. To study the individual-level evolutionary dynamics, we adopt different strategy update rules and investigate their effects on charity and cooperation. These rules can be classified into two global rules: random selection rule in which individuals randomly update strategies, and threshold selection rule where only those with payoffs below a threshold update strategies. Simulation results show that random selection enhances the cooperation level, while threshold selection lowers the threshold of the multiplication factor to maintain cooperation. When charity is considered, it is incapable in promoting cooperation under random selection, whereas it promotes cooperation under threshold selection. Interestingly, the evolution of charity strongly depends on the dispersion of payoff acquisitions of the population, which agrees with previous results. Our work may shed light on understanding human egalitarianism.

Investigations of Students' Motivation Towards Learning Secondary School Physics through Mastery Learning Approach

ERIC Educational Resources Information Center

Changeiywo, Johnson M.; Wambugu, P. W.; Wachanga, S. W.

2011-01-01

Teaching method is a major factor that affects students' motivation to learn physics. This study investigated the effects of using mastery learning approach (MLA) on secondary school students' motivation to learn physics. Solomon four non-equivalent control group design under the quasi-experimental research method was used in which a random sample…

An Experimental Investigation into the Efficiency of Cooperative Learning with Consideration of Multiple Grouping Criteria

ERIC Educational Resources Information Center

Hsiung, C. -M.

2010-01-01

The present study conducts an experimental investigation to compare the efficiency of the cooperative learning method with that of the traditional learning method. A total of 42 engineering students are randomly assigned to the two learning conditions and are formed into mixed-ability groups comprising three team members. In addition to the…

Determinants of Broader Impacts Activities: A Survey of NSF-Funded Investigators

ERIC Educational Resources Information Center

Nagy, Dianne

2016-01-01

This study investigated the factors that shape the broader impacts activities of NSF grant recipients. A random sample of NSF grantees was surveyed about the type and quality of their broader impacts activities, their views on knowledge production and the democratization of science, their experience and training, and the existence of a supportive…

Investigating the Effect of Complexity Factors in Stoichiometry Problems Using Logistic Regression and Eye Tracking

ERIC Educational Resources Information Center

Tang, Hui; Kirk, John; Pienta, Norbert J.

2014-01-01

This paper includes two experiments, one investigating complexity factors in stoichiometry word problems, and the other identifying students' problem-solving protocols by using eye-tracking technology. The word problems used in this study had five different complexity factors, which were randomly assigned by a Web-based tool that we developed. The…

Cost-effectiveness of health research study participant recruitment strategies: a systematic review.

PubMed

Huynh, Lynn; Johns, Benjamin; Liu, Su-Hsun; Vedula, S Swaroop; Li, Tianjing; Puhan, Milo A

2014-10-01

A large fraction of the cost of conducting clinical trials is allocated to recruitment of participants. A synthesis of findings from studies that evaluate the cost and effectiveness of different recruitment strategies will inform investigators in designing cost-efficient clinical trials. To systematically identify, assess, and synthesize evidence from published comparisons of the cost and yield of strategies for recruitment of participants to health research studies. We included randomized studies in which two or more strategies for recruitment of participants had been compared. We focused our economic evaluation on studies that randomized participants to different recruitment strategies. We identified 10 randomized studies that compared recruitment strategies, including monetary incentives (cash or prize), direct contact (letters or telephone call), and medical referral strategies. Only two of the 10 studies compared strategies for recruiting participants to clinical trials. We found that allocating additional resources to recruit participants using monetary incentives or direct contact yielded between 4% and 23% additional participants compared to using neither strategy. For medical referral, recruitment of prostate cancer patients by nurses was cost-saving compared to recruitment by consultant urologists. For all underlying study designs, monetary incentives cost more than direct contact with potential participants, with a median incremental cost per recruitment ratio of Int$72 (Int$-International dollar, a theoretical unit of currency) for monetary incentive strategy compared to Int$28 for direct contact strategy. Only monetary incentives and source of referral were evaluated for recruiting participants into clinical trials. We did not review studies that presented non-monetary cost or lost opportunity cost. We did not adjust for the number of study recruitment sites or the study duration in our economic evaluation analysis. Systematic and explicit reporting of cost and effectiveness of recruitment strategies from randomized comparisons is required to aid investigators to select cost-efficient strategies for recruiting participants to health research studies including clinical trials. © The Author(s) 2014.

Development Testing and Subsequent Failure Investigation of a Spring Strut Mechanism

NASA Technical Reports Server (NTRS)

Dervan, Jared; Robertson, Brandan; Staab, Lucas; Culberson, Michael; Pellicciotti, Joseph

2014-01-01

The NASA Engineering and Safety Center (NESC) and Lockheed Martin (LM) performed random vibration testing on a single spring strut development unit to assess its ability to withstand qualification level random vibration environments. Failure of the strut while exposed to random vibration resulted in a follow-on failure investigation, design changes, and additional development tests. This paper focuses on the results of the failure investigations referenced in detail in the NESC final report [1] including identified lessons learned to aid in future design iterations of the spring strut and to help other mechanism developers avoid similar pitfalls.

Development Testing and Subsequent Failure Investigation of a Spring Strut Mechanism

NASA Technical Reports Server (NTRS)

Dervan, Jared; Robertson, Brandon; Staab, Lucas; Culberson, Michael; Pellicciotti, Joseph

2014-01-01

The NASA Engineering and Safety Center (NESC) and Lockheed Martin (LM) performed random vibration testing on a single spring strut development unit to assess its ability to withstand qualification level random vibration environments. Failure of the strut while exposed to random vibration resulted in a follow-on failure investigation, design changes, and additional development tests. This paper focuses on the results of the failure investigations referenced in detail in the NESC final report including identified lessons learned to aid in future design iterations of the spring strut and to help other mechanism developers avoid similar pitfalls.

A nonrandomized cohort and a randomized study of local control of large hepatocarcinoma by targeting intratumoral lactic acidosis

PubMed Central

Chao, Ming; Wu, Hao; Jin, Kai; Li, Bin; Wu, Jianjun; Zhang, Guangqiang; Yang, Gong; Hu, Xun

2016-01-01

Study design: Previous works suggested that neutralizing intratumoral lactic acidosis combined with glucose deprivation may deliver an effective approach to control tumor. We did a pilot clinical investigation, including a nonrandomized (57 patients with large HCC) and a randomized controlled (20 patients with large HCC) studies. Methods: The patients were treated with transarterial chemoembolization (TACE) with or without bicarbonate local infusion into tumor. Results: In the nonrandomized controlled study, geometric mean of viable tumor residues (VTR) in TACE with bicarbonate was 6.4-fold lower than that in TACE without bicarbonate (7.1% [95% CI: 4.6%–10.9%] vs 45.6% [28.9%–72.0%]; p<0.0001). This difference was recapitulated by a subsequent randomized controlled study. TACE combined with bicarbonate yielded a 100% objective response rate (ORR), whereas the ORR treated with TACE alone was 44.4% (nonrandomized) and 63.6% (randomized). The survival data suggested that bicarbonate may bring survival benefit. Conclusion: Bicarbonate markedly enhances the anticancer activity of TACE. Clinical trail registration: ChiCTR-IOR-14005319. DOI: http://dx.doi.org/10.7554/eLife.15691.001 PMID:27481188

Some Aspects of the Investigation of Random Vibration Influence on Ride Comfort

NASA Astrophysics Data System (ADS)

DEMIĆ, M.; LUKIĆ, J.; MILIĆ, Ž.

2002-05-01

Contemporary vehicles must satisfy high ride comfort criteria. This paper attempts to develop criteria for ride comfort improvement. The highest loading levels have been found to be in the vertical direction and the lowest in lateral direction in passenger cars and trucks. These results have formed the basis for further laboratory and field investigations. An investigation of the human body behaviour under random vibrations is reported in this paper. The research included two phases; biodynamic research and ride comfort investigation. A group of 30 subjects was tested. The influence of broadband random vibrations on the human body was examined through the seat-to-head transmissibility function (STHT). Initially, vertical and fore and aft vibrations were considered. Multi-directional vibration was also investigated. In the biodynamic research, subjects were exposed to 0·55, 1·75 and 2·25 m/s2 r.m.s. vibration levels in the 0·5- 40 Hz frequency domain. The influence of sitting position on human body behaviour under two axial vibrations was also examined. Data analysis showed that the human body behaviour under two-directional random vibrations could not be approximated by superposition of one-directional random vibrations. Non-linearity of the seated human body in the vertical and fore and aft directions was observed. Seat-backrest angle also influenced STHT. In the second phase of experimental research, a new method for the assessment of the influence of narrowband random vibration on the human body was formulated and tested. It included determination of equivalent comfort curves in the vertical and fore and aft directions under one- and two-directional narrowband random vibrations. Equivalent comfort curves for durations of 2·5, 4 and 8 h were determined.

Understanding the Effects of Different Study Methods on Retention of Information and Transfer of Learning

ERIC Educational Resources Information Center

Egan, Rylan G.

2012-01-01

Introduction: The following study investigates relationships between spaced practice (re-studying after a delay) and transfer of learning. Specifically, the impact on learners ability to transfer learning after participating in spaced model-building or unstructured study of narrated text. Method: Subjects were randomly assigned either to a…

Investigating the Randomness of Numbers

ERIC Educational Resources Information Center

Pendleton, Kenn L.

2009-01-01

The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

Investigation of the influence of the proximity effect and randomness on a photolithographically fabricated photonic crystal nanobeam cavity

NASA Astrophysics Data System (ADS)

Tetsumoto, Tomohiro; Kumazaki, Hajime; Ishida, Rammaru; Tanabe, Takasumi

2018-01-01

Recent progress on the fabrication techniques used in silicon photonics foundries has enabled us to fabricate photonic crystal (PhC) nanocavities using a complementary metal-oxide-semiconductor (CMOS) compatible process. A high Q two-dimensional PhC nanocavity and a one-dimensional nanobeam PhC cavity with a Q exceeding 100 thousand have been fabricated using ArF excimer laser immersion lithography. These are important steps toward the fusion of silicon photonics devices and PhC devices. Although the fabrication must be reproducible for industrial applications, the properties of PhC nanocavities are sensitively affected by the proximity effect and randomness. In this study, we quantitatively investigated the influence of the proximity effect and randomness on a silicon nanobeam PhC cavity. First, we discussed the optical properties of cavities defined with one- and two-step exposure methods, which revealed the necessity of a multi-stage exposure process for our structure. Then, we investigated the impact of block structures placed next to the cavities. The presence of the blocks modified the resonant wavelength of the cavities by about 10 nm. The highest Q we obtained was over 100 thousand. We also discussed the influence of photomask misalignment, which is also a possible cause of disorders in the photolithographic fabrication process. This study will provide useful information for fabricating integrated photonic circuits with PhC nanocavities using a photolithographic process.

A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease.

PubMed

Mente, Andrew; de Koning, Lawrence; Shannon, Harry S; Anand, Sonia S

2009-04-13

Although a wealth of literature links dietary factors and coronary heart disease (CHD), the strength of the evidence supporting valid associations has not been evaluated systematically in a single investigation. We conducted a systematic search of MEDLINE for prospective cohort studies or randomized trials investigating dietary exposures in relation to CHD. We used the Bradford Hill guidelines to derive a causation score based on 4 criteria (strength, consistency, temporality, and coherence) for each dietary exposure in cohort studies and examined for consistency with the findings of randomized trials. Strong evidence supports valid associations (4 criteria satisfied) of protective factors, including intake of vegetables, nuts, and "Mediterranean" and high-quality dietary patterns with CHD, and associations of harmful factors, including intake of trans-fatty acids and foods with a high glycemic index or load. Among studies of higher methodologic quality, there was also strong evidence for monounsaturated fatty acids and "prudent" and "western" dietary patterns. Moderate evidence (3 criteria) of associations exists for intake of fish, marine omega-3 fatty acids, folate, whole grains, dietary vitamins E and C, beta carotene, alcohol, fruit, and fiber. Insufficient evidence (< or =2 criteria) of association is present for intake of supplementary vitamin E and ascorbic acid (vitamin C); saturated and polyunsaturated fatty acids; total fat; alpha-linolenic acid; meat; eggs; and milk. Among the dietary exposures with strong evidence of causation from cohort studies, only a Mediterranean dietary pattern is related to CHD in randomized trials. The evidence supports a valid association of a limited number of dietary factors and dietary patterns with CHD. Future evaluation of dietary patterns, including their nutrient and food components, in cohort studies and randomized trials is recommended.

Treatment of Middle East Respiratory Syndrome with a combination of lopinavir-ritonavir and interferon-β1b (MIRACLE trial): study protocol for a randomized controlled trial.

PubMed

Arabi, Yaseen M; Alothman, Adel; Balkhy, Hanan H; Al-Dawood, Abdulaziz; AlJohani, Sameera; Al Harbi, Shmeylan; Kojan, Suleiman; Al Jeraisy, Majed; Deeb, Ahmad M; Assiri, Abdullah M; Al-Hameed, Fahad; AlSaedi, Asim; Mandourah, Yasser; Almekhlafi, Ghaleb A; Sherbeeni, Nisreen Murad; Elzein, Fatehi Elnour; Memon, Javed; Taha, Yusri; Almotairi, Abdullah; Maghrabi, Khalid A; Qushmaq, Ismael; Al Bshabshe, Ali; Kharaba, Ayman; Shalhoub, Sarah; Jose, Jesna; Fowler, Robert A; Hayden, Frederick G; Hussein, Mohamed A

2018-01-30

It had been more than 5 years since the first case of Middle East Respiratory Syndrome coronavirus infection (MERS-CoV) was recorded, but no specific treatment has been investigated in randomized clinical trials. Results from in vitro and animal studies suggest that a combination of lopinavir/ritonavir and interferon-β1b (IFN-β1b) may be effective against MERS-CoV. The aim of this study is to investigate the efficacy of treatment with a combination of lopinavir/ritonavir and recombinant IFN-β1b provided with standard supportive care, compared to treatment with placebo provided with standard supportive care in patients with laboratory-confirmed MERS requiring hospital admission. The protocol is prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. Hospitalized adult patients with laboratory-confirmed MERS will be enrolled in this recursive, two-stage, group sequential, multicenter, placebo-controlled, double-blind randomized controlled trial. The trial is initially designed to include 2 two-stage components. The first two-stage component is designed to adjust sample size and determine futility stopping, but not efficacy stopping. The second two-stage component is designed to determine efficacy stopping and possibly readjustment of sample size. The primary outcome is 90-day mortality. This will be the first randomized controlled trial of a potential treatment for MERS. The study is sponsored by King Abdullah International Medical Research Center, Riyadh, Saudi Arabia. Enrollment for this study began in November 2016, and has enrolled thirteen patients as of Jan 24-2018. ClinicalTrials.gov, ID: NCT02845843 . Registered on 27 July 2016.

Does Embryo Culture Medium Influence the Health and Development of Children Born after In Vitro Fertilization?

PubMed

Bouillon, Céline; Léandri, Roger; Desch, Laurent; Ernst, Alexandra; Bruno, Céline; Cerf, Charline; Chiron, Alexandra; Souchay, Céline; Burguet, Antoine; Jimenez, Clément; Sagot, Paul; Fauque, Patricia

2016-01-01

In animal studies, extensive data revealed the influence of culture medium on embryonic development, foetal growth and the behaviour of offspring. However, this impact has never been investigated in humans. For the first time, we investigated in depth the effects of embryo culture media on health, growth and development of infants conceived by In Vitro Fertilization until the age of 5 years old. This single-centre cohort study was based on an earlier randomized study. During six months, in vitro fertilization attempts (No. 371) were randomized according to two media (Single Step Medium--SSM group) or Global medium (Global group). This randomized study was stopped prematurely as significantly lower pregnancy and implantation rates were observed in the SSM group. Singletons (No. 73) conceived in the randomized study were included (42 for Global and 31 for SSM). The medical data for gestational, neonatal and early childhood periods were extracted from medical records and parental interviews (256 variables recorded). The developmental profiles of the children in eight domains (social, self-help, gross motor, fine motor, expressive language, language comprehension, letter knowledge and number knowledge--270 items) were compared in relation to the culture medium. The delivery rate was significantly lower in the SSM group than in the Global group (p<0.05). The culture medium had no significant effect on birthweight, risk of malformation (minor and major), growth and the frequency of medical concerns. However, the children of the Global group were less likely than those of the SSM group to show developmental problems (p = 0.002), irrespective of the different domains. In conclusion, our findings showed that the embryo culture medium may have an impact on further development.

Cosmetic outcome of skin adhesives versus transcutaneous sutures in laparoscopic port-site wounds: a prospective randomized controlled trial.

PubMed

Buchweitz, Olaf; Frye, Christian; Moeller, Claus Peter; Nugent, Wolfgang; Krueger, Eckart; Nugent, Andreas; Biel, Peter; Juergens, Sven

2016-06-01

In an elective laparoscopic surgery, the cosmetic outcome becomes increasingly important. We conducted a study to evaluate the cosmetic outcome 3 months after a laparoscopic procedure and compared skin adhesive (SA) versus transcutaneous suture (TS). A randomized, controlled, prospective study was conducted at a single study centre in Hamburg, Germany. Seventy-seven patients undergoing laparoscopic surgery with two lower abdominal port sites met the study requirements. It was decided randomly which port site would be closed with SA. The opposite site was closed with TS. Wounds were assessed after 7-12 days and after 3 months. Cosmetic outcome was measured by a visual analogue scale (VAS) completed by the patient, by the Hollander wound evaluation scale (HWES) and by the judgement of blinded investigators. Seventy-seven subjects were randomized. Complete data from the 3-month follow-up visit were available from 56 patients (72.7 %). The VAS scale ranged from 0 to 100 mm with "0" representing the best possible cosmetic outcome. Median satisfaction was 2 mm in the TS group and 3 mm in the SA group. The mean was high in both groups 4.6 (s = 13.1) versus 3.8 mm (s = 4.6). The outcome was neither clinically nor statistically significant. Cosmetic outcome was assessed by an investigator, and the HWES showed no difference. In regard to complications, no difference was found between SA and TS, either. In conclusion this study demonstrated that closure of laparoscopic port-site wounds leads to equivalent outcomes whether SAs or TSs are used. Complications are rare in both methods. Thus, SAs seem to be a valid alternative to sutures in laparoscopic surgery. Registration site: www.clinicaltrials.gov . NCT02179723.

Patients’ Perspectives of Enrollment in Research Without Consent- The Patients’ Experiences in Emergency Research- ProTECT Study (PEER-ProTECT)

PubMed Central

Dickert, Neal W; Scicluna, Victoria M; Baren, Jill M; Biros, Michelle H; Fleischman, Ross J; Govindarajan, Prasanthi R; Jones, Elizabeth B; Pancioli, Arthur M; Wright, David W; Pentz, Rebecca D

2016-01-01

Objective Research in acute illness often requires an exception from informed consent (EFIC). Few studies have assessed the views of patients enrolled in EFIC trials. This study was designed to assess the views of patients and their surrogates of EFIC enrollment in a randomized, placebo-controlled trial of an investigational agent for traumatic brain injury. Design Interactive interview study. Setting Nested within the Progesterone for the Treatment of Traumatic Brain Injury (ProTECT III) trial, a Phase III randomized controlled trial in acute traumatic brain injury (TBI). Participants Patients and surrogates (for patients incapable of being interviewed) enrolled in ProTECT III under EFIC at 12 sites. Measurements Interviews focused on respondents’ acceptance of EFIC enrollment in ProTECT, use of placebo and randomization, understanding of major study elements, and views regarding regulatory protections. Descriptive statistical analysis was performed; textual data were analyzed thematically. Main Results 85 individuals were interviewed. 84% had positive attitudes toward ProTECT III inclusion. 78% found their inclusion under EFIC acceptable, and 72% found use of EFIC in ProTECT III acceptable in general. Only 2 respondents clearly disagreed with both personal and general EFIC enrollment. The most common concerns (26%) related to absence of consent. 80% and 92% were accepting of placebo use and randomization, respectively. Though there were few black respondents (n=11), they were less accepting of personal EFIC enrollment than white respondents (55% vs 83%, p= 0.0494). Conclusions Acceptance of EFIC in this placebo-controlled trial of an investigational agent was high and exceeded acceptance among community consultation participants. EFIC enrollment appears generally consistent with patients’ preferences. PMID:25574795

Study Habits and Academic Achievement of Kashmiri & Ladakhi Adolescent Girls: A Comparative Study

ERIC Educational Resources Information Center

Nadeem, N. A.; Puja, Javeed Ahamd; Bhat, Shabir Ahmad

2014-01-01

The present study was conducted to study the Study Habits and Academic Achievement of Adolescents girls in Jammu and Kashmir. 400 sample subjects were selected randomly from two ethnic groups' viz. Kashmiri and Ladakhi. The investigators used Palsane & Sharma's study habits inventory (PSSHI) to collect data from the field. Certain statistical…

The efficacy of the addition of the Pilates method over a minimal intervention in the treatment of chronic nonspecific low back pain: a study protocol of a randomized controlled trial☆

PubMed Central

Miyamoto, Gisela C.; Costa, Leonardo O.P.; Galvanin, Thalissa; Cabral, Cristina M.N.

2011-01-01

Objective There is little high-quality evidence on the efficacy of the Pilates-based exercises for the treatment of chronic nonspecific low back pain. Therefore, the objective of this paper is to present a study protocol to investigate the efficacy of adding Pilates-based exercises to a minimum intervention in patients with chronic non-specific low back pain. Methods This randomized controlled trial will recruit 86 patients of both sexes, aged between 18 and 60 years, with chronic non-specific low back pain. The participants will be randomly allocated into 2 treatment groups: the Booklet Group, which will receive a booklet with postural orientations, and the Pilates Group, which will receive the same booklet in addition to a Pilates-based exercises program. The general and specific functional capacities of the patient, kinesiophobia, pain intensity, and the global perceived effect will be evaluated by a blinded assessor before randomization and at 6 weeks and 6 months after randomization. In addition, the expectations of the participants and their confidence in the treatment will be evaluated before the randomization and after the first treatment session, respectively. Conclusions It is hoped that the results of this study will provide high-quality evidence on the usefulness of Pilates-based exercises in the treatment of chronic non-specific low back pain. PMID:22654682

Effectiveness of anisodamine for the treatment of critically ill patients with septic shock (ACIdoSIS study): study protocol for randomized controlled trial

PubMed Central

Zhou, Jiancang; Shang, You; Wang, Xin’an; Yin, Rui; Zhu, Zhenhua; Chen, Wensen; Tian, Xin; Yu, Yuetian; Zuo, Xiangrong; Chen, Kun; Ji, Xuqing; Ni, Hongying

2015-01-01

Background Septic shock is an important contributor of mortality in the intensive care unit (ICU). Although strenuous effort has been made to improve its outcome, the mortality rate is only marginally decreased. The present study aimed to investigate the effectiveness of anisodamine in the treatment of septic shock, in the hope that the drug will provide alternatives to the treatment of septic shock. Methods The study is a multi-center randomized controlled clinical trial. Study population will include critically ill patients with septic shock requiring vasopressor use. Blocked randomization was performed where anisodamine and control treatments were allocated at random in a ratio of 1:1 in blocks of sizes 2, 4, 6, 8, and 10 to 354 subjects. Interim analysis will be performed. The primary study end point is the hospital mortality, and other secondary study endpoints include ICU mortality, length of stay in ICU and hospital, organ failure free days. Adverse events including new onset psychosis, urinary retention, significant hypotension and tachycardia will be reported. Discussion The study will provide new insight into the treatment of septic shock and can help to reduce mortality rate of septic shock. Trial registration NCT02442440 (https://register.clinicaltrials.gov/). PMID:26605292

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.

Knowledge translation interventions for critically ill patients: a systematic review*.

PubMed

Sinuff, Tasnim; Muscedere, John; Adhikari, Neill K J; Stelfox, Henry T; Dodek, Peter; Heyland, Daren K; Rubenfeld, Gordon D; Cook, Deborah J; Pinto, Ruxandra; Manoharan, Venika; Currie, Jan; Cahill, Naomi; Friedrich, Jan O; Amaral, Andre; Piquette, Dominique; Scales, Damon C; Dhanani, Sonny; Garland, Allan

2013-11-01

We systematically reviewed ICU-based knowledge translation studies to assess the impact of knowledge translation interventions on processes and outcomes of care. We searched electronic databases (to July, 2010) without language restrictions and hand-searched reference lists of relevant studies and reviews. Two reviewers independently identified randomized controlled trials and observational studies comparing any ICU-based knowledge translation intervention (e.g., protocols, guidelines, and audit and feedback) to management without a knowledge translation intervention. We focused on clinical topics that were addressed in greater than or equal to five studies. Pairs of reviewers abstracted data on the clinical topic, knowledge translation intervention(s), process of care measures, and patient outcomes. For each individual or combination of knowledge translation intervention(s) addressed in greater than or equal to three studies, we summarized each study using median risk ratio for dichotomous and standardized mean difference for continuous process measures. We used random-effects models. Anticipating a small number of randomized controlled trials, our primary meta-analyses included randomized controlled trials and observational studies. In separate sensitivity analyses, we excluded randomized controlled trials and collapsed protocols, guidelines, and bundles into one category of intervention. We conducted meta-analyses for clinical outcomes (ICU and hospital mortality, ventilator-associated pneumonia, duration of mechanical ventilation, and ICU length of stay) related to interventions that were associated with improvements in processes of care. From 11,742 publications, we included 119 investigations (seven randomized controlled trials, 112 observational studies) on nine clinical topics. Interventions that included protocols with or without education improved continuous process measures (seven observational studies and one randomized controlled trial; standardized mean difference [95% CI]: 0.26 [0.1, 0.42]; p = 0.001 and four observational studies and one randomized controlled trial; 0.83 [0.37, 1.29]; p = 0.0004, respectively). Heterogeneity among studies within topics ranged from low to extreme. The exclusion of randomized controlled trials did not change our results. Single-intervention and lower-quality studies had higher standardized mean differences compared to multiple-intervention and higher-quality studies (p = 0.013 and 0.016, respectively). There were no associated improvements in clinical outcomes. Knowledge translation interventions in the ICU that include protocols with or without education are associated with the greatest improvements in processes of critical care.

Deterministic chaotic dynamics of Raba River flow (Polish Carpathian Mountains)

NASA Astrophysics Data System (ADS)

Kędra, Mariola

2014-02-01

Is the underlying dynamics of river flow random or deterministic? If it is deterministic, is it deterministic chaotic? This issue is still controversial. The application of several independent methods, techniques and tools for studying daily river flow data gives consistent, reliable and clear-cut results to the question. The outcomes point out that the investigated discharge dynamics is not random but deterministic. Moreover, the results completely confirm the nonlinear deterministic chaotic nature of the studied process. The research was conducted on daily discharge from two selected gauging stations of the mountain river in southern Poland, the Raba River.

A study of optimal abstract jamming strategies vs. noncoherent MFSK

NASA Technical Reports Server (NTRS)

Mceliece, R. J.; Rodemich, E. R.

1983-01-01

The present investigation is concerned with the performance of uncoded MFSK modulation in the presence of arbitrary additive jamming, taking into account the objective to devise robust antijamming strategies. An abstract model is considered, giving attention to the signal strength as a nonnegative real number X, the employment of X as a random variable, its distribution function G(x), the transmitter's strategy G, the jamming noise as an M-dimensional random vector Z, and the error probability. A summary of previous work on the considered problem is provided, and the results of the current study are presented.

Use of Random and Site-Directed Mutagenesis to Probe Protein Structure-Function Relationships: Applied Techniques in the Study of Helicobacter pylori.

PubMed

Whitmire, Jeannette M; Merrell, D Scott

2017-01-01

Mutagenesis is a valuable tool to examine the structure-function relationships of bacterial proteins. As such, a wide variety of mutagenesis techniques and strategies have been developed. This chapter details a selection of random mutagenesis methods and site-directed mutagenesis procedures that can be applied to an array of bacterial species. Additionally, the direct application of the techniques to study the Helicobacter pylori Ferric Uptake Regulator (Fur) protein is described. The varied approaches illustrated herein allow the robust investigation of the structural-functional relationships within a protein of interest.

Analysis of axial compressive loaded beam under random support excitations

NASA Astrophysics Data System (ADS)

Xiao, Wensheng; Wang, Fengde; Liu, Jian

2017-12-01

An analytical procedure to investigate the response spectrum of a uniform Bernoulli-Euler beam with axial compressive load subjected to random support excitations is implemented based on the Mindlin-Goodman method and the mode superposition method in the frequency domain. The random response spectrum of the simply supported beam subjected to white noise excitation and to Pierson-Moskowitz spectrum excitation is investigated, and the characteristics of the response spectrum are further explored. Moreover, the effect of axial compressive load is studied and a method to determine the axial load is proposed. The research results show that the response spectrum mainly consists of the beam's additional displacement response spectrum when the excitation is white noise; however, the quasi-static displacement response spectrum is the main component when the excitation is the Pierson-Moskowitz spectrum. Under white noise excitation, the amplitude of the power spectral density function decreased as the axial compressive load increased, while the frequency band of the vibration response spectrum increased with the increase of axial compressive load.

Modeling and complexity of stochastic interacting Lévy type financial price dynamics

NASA Astrophysics Data System (ADS)

Wang, Yiduan; Zheng, Shenzhou; Zhang, Wei; Wang, Jun; Wang, Guochao

2018-06-01

In attempt to reproduce and investigate nonlinear dynamics of security markets, a novel nonlinear random interacting price dynamics, which is considered as a Lévy type process, is developed and investigated by the combination of lattice oriented percolation and Potts dynamics, which concerns with the instinctive random fluctuation and the fluctuation caused by the spread of the investors' trading attitudes, respectively. To better understand the fluctuation complexity properties of the proposed model, the complexity analyses of random logarithmic price return and corresponding volatility series are preformed, including power-law distribution, Lempel-Ziv complexity and fractional sample entropy. In order to verify the rationality of the proposed model, the corresponding studies of actual security market datasets are also implemented for comparison. The empirical results reveal that this financial price model can reproduce some important complexity features of actual security markets to some extent. The complexity of returns decreases with the increase of parameters γ1 and β respectively, furthermore, the volatility series exhibit lower complexity than the return series

The role of calcium in the prevention of cardiovascular disease--a review of observational studies and randomized clinical trials.

PubMed

Rautiainen, Susanne; Wang, Lu; Manson, JoAnn E; Sesso, Howard D

2013-11-01

Calcium is a mineral that is important for bone health and has also been suggested to play a role in the prevention of cardiovascular disease (CVD). Lately, the potential effects of both inadequate and excessive calcium intake have received growing attention. In this review, we summarize the evidence from experimental, epidemiologic, and clinical studies investigating the role of calcium intake, either from the diet or from supplements, as well as blood concentrations, in relation to the risk of CVD in adults. In vitro and in vivo laboratory studies suggest that calcium may be involved in CVD development through multiple pathways, including blood cholesterol, insulin secretion and sensitivity, vasodilation, inflammatory profile, thrombosis, obesity, and vascular calcification. Several prospective epidemiologic studies have examined how dietary or supplemental calcium intake is associated with CVD incidence or mortality in middle-aged and older adults, and the results are inconsistent. Prospective studies investigating blood concentrations of calcium have also reported mixed results. However, changes in blood calcium concentrations may reflect a disturbed calcium phosphate balance, which is associated with increased risk of CVD. To date there is no randomized clinical trial that has been designed specifically to test the effect of calcium supplementation on the risk of CVD as the primary end point. Existing trials have performed secondary analyses, and most of them have been conducted among postmenopausal women. These trials suggest that calcium supplementation has no effect on CVD development; however, they do not allow a definitive conclusion to be drawn. The average daily intake of calcium is low in many populations; however, the evidence for a potential role of dietary or supplemental calcium in the prevention of CVD remains insufficient and inconclusive. Only large-scale randomized trials designed to investigate the effects of calcium supplementation on CVD events as the primary end point, as well as short-term trials investigating the effect on coronary biomarkers, can provide a definitive answer.

Assessment of Social Media Utilization and Study Habit of Students of Tertiary Institutions in Katsina State

ERIC Educational Resources Information Center

Olutola, Adekunle Thomas; Olatoye, Olufunke Omotoke; Olatoye, Rafiu Ademola

2016-01-01

This study investigated assessment of social media utilization and study habits of students of tertiary institutions in Katsina State. The descriptive survey design was adopted for this study. Three hundred and eighty-one (381) students' of tertiary institutions in Katsina State were randomly selected for the study. Researchers'-designed…

Random pinning elucidates the nature of melting transition in two-dimensional core-softened potential system

NASA Astrophysics Data System (ADS)

Tsiok, E. N.; Fomin, Y. D.; Ryzhov, V. N.

2018-01-01

Despite about forty years of investigations, the nature of the melting transition in two dimensions is not completely clear. In the framework of the most popular Berezinskii-Kosterlitz-Thouless-Halperin-Nelson-Young (BKTHNY) theory, 2D systems melt through two continuous Berezinskii-Kosterlitz-Thouless (BKT) transitions with intermediate hexatic phase. The conventional first-order transition is also possible. On the other hand, recently on the basis of computer simulations the new melting scenario was proposed with continuous BKT type solid-hexatic transition and first order hexatic-liquid transition. However, in the simulations the hexatic phase is extremely narrow that makes its study difficult. In the present paper, we propose to apply the random pinning to investigate the hexatic phase in more detail. The results of molecular dynamics simulations of two dimensional system having core-softened potentials with narrow repulsive step which is similar to the soft disk system are outlined. The system has a small fraction of pinned particles giving quenched disorder. Random pinning widens the hexatic phase without changing the melting scenario and gives the possibility to study the behavior of the diffusivity and order parameters in the vicinity of the melting transition and inside the hexatic phase.

A Long-Term Follow-Up of the Efficacy of Nature-Based Therapy for Adults Suffering from Stress-Related Illnesses on Levels of Healthcare Consumption and Sick-Leave Absence: A Randomized Controlled Trial.

PubMed

Corazon, Sus Sola; Nyed, Patrik Karlsson; Sidenius, Ulrik; Poulsen, Dorthe Varning; Stigsdotter, Ulrika Karlsson

2018-01-15

Stress-related illnesses are a growing health problem in the Western world; which also has economic significance for society. As a consequence; there is a growing demand for effective treatments. The study investigates the long-term efficacy of the Nacadia ® nature-based therapy (NNBT) by comparing it to the efficacy of a validated cognitive behavioral therapy, called STreSS. The study is designed as a randomized controlled trial in which 84 participants are randomly allocated between the treatments. Long-term efficacy is investigated through data extracts from the national database of Statistics Denmark on the sick leave and the health-care consumption. The results show that both the NNBT and the STreSS lead to a significant decrease in number of contacts with a general practitioner in the period from twelve months prior to treatment to twelve months after treatment; and, a significant decrease in long-term sick leave from the month prior to treatment to twelve months after treatment. The positive long-term effects provide validation for the NNBT as an efficient treatment of stress-related illnesses.

A Long-Term Follow-Up of the Efficacy of Nature-Based Therapy for Adults Suffering from Stress-Related Illnesses on Levels of Healthcare Consumption and Sick-Leave Absence: A Randomized Controlled Trial

PubMed Central

Corazon, Sus Sola; Nyed, Patrik Karlsson; Sidenius, Ulrik

2018-01-01

Stress-related illnesses are a growing health problem in the Western world; which also has economic significance for society. As a consequence; there is a growing demand for effective treatments. The study investigates the long-term efficacy of the Nacadia® nature-based therapy (NNBT) by comparing it to the efficacy of a validated cognitive behavioral therapy, called STreSS. The study is designed as a randomized controlled trial in which 84 participants are randomly allocated between the treatments. Long-term efficacy is investigated through data extracts from the national database of Statistics Denmark on the sick leave and the health-care consumption. The results show that both the NNBT and the STreSS lead to a significant decrease in number of contacts with a general practitioner in the period from twelve months prior to treatment to twelve months after treatment; and, a significant decrease in long-term sick leave from the month prior to treatment to twelve months after treatment. The positive long-term effects provide validation for the NNBT as an efficient treatment of stress-related illnesses. PMID:29342952

Divergence instability of pipes conveying fluid with uncertain flow velocity

NASA Astrophysics Data System (ADS)

Rahmati, Mehdi; Mirdamadi, Hamid Reza; Goli, Sareh

2018-02-01

This article deals with investigation of probabilistic stability of pipes conveying fluid with stochastic flow velocity in time domain. As a matter of fact, this study has focused on the randomness effects of flow velocity on stability of pipes conveying fluid while most of research efforts have only focused on the influences of deterministic parameters on the system stability. The Euler-Bernoulli beam and plug flow theory are employed to model pipe structure and internal flow, respectively. In addition, flow velocity is considered as a stationary random process with Gaussian distribution. Afterwards, the stochastic averaging method and Routh's stability criterion are used so as to investigate the stability conditions of system. Consequently, the effects of boundary conditions, viscoelastic damping, mass ratio, and elastic foundation on the stability regions are discussed. Results delineate that the critical mean flow velocity decreases by increasing power spectral density (PSD) of the random velocity. Moreover, by increasing PSD from zero, the type effects of boundary condition and presence of elastic foundation are diminished, while the influences of viscoelastic damping and mass ratio could increase. Finally, to have a more applicable study, regression analysis is utilized to develop design equations and facilitate further analyses for design purposes.

Experimental transmission of Corynebacterium pseudotuberculosis in horses by house flies

USDA-ARS?s Scientific Manuscript database

The route of infection of pigeon fever remains undetermined. The purpose of this study was to investigate house flies (Musca domestica L.) as vectors of Corynebacterium pseudotuberculosis in horses. Eight ponies were used in a randomized, controlled, blinded experimental study. Ten wounds were creat...

Determinants of Effective Communication among Undergraduate Students

ERIC Educational Resources Information Center

Anvari, Roya; Atiyaye, Dauda Mohammed

2014-01-01

This study aims to investigate the relationship between effective communication and transferring information. In the present correlational study, a cross-sectional research design was employed, and data were collected using a questionnaire-based survey. 46 students were chosen based on random sampling and questionnaires were distributed among…

An Investigation of Factors Influencing Learning in the Mentally Retarded, and Their Use in the Design of Instructional Materials; Effects of a Set for Delayed Response on Recall by MR's. Interim Report.

ERIC Educational Resources Information Center

Seitz, Sue; Morris, Dan

In a study on short term memory, 32 educable mentally retarded subjects (mean IQ 62.68, mean mental age 103.78 months) were randomly assigned to each of the four experimental conditions. An automated machine presented the stimuli (32 three-letter words) and the interference items (a list of random numbers read aloud between stimuli presentations).…

Effects of Guided Imagery on Postoperative Outcomes in Patients Undergoing Same-Day Surgical Procedures: A Randomized, Single-Blind Study

DTIC Science & Technology

2010-06-01

2O0O;9Ot3):706-712. 20. Bertrand P, Maye J. A description of the indices of heart rate variabil- ity in orofacial pain paticnis. Bcihcsda, MD: National...neck proce- dures were randomly assigned into 2 groups for this single-blind investigation. Anxiety and baseline pain levels were documented...control group patients received no intervention. Data were collected on pain and nar- cotic consumption at 7- and 2-hour postoperative inter- vals. In

A perfect correlate does not a surrogate make

PubMed Central

Baker, Stuart G; Kramer, Barnett S

2003-01-01

Background There is common belief among some medical researchers that if a potential surrogate endpoint is highly correlated with a true endpoint, then a positive (or negative) difference in potential surrogate endpoints between randomization groups would imply a positive (or negative) difference in unobserved true endpoints between randomization groups. We investigate this belief when the potential surrogate and unobserved true endpoints are perfectly correlated within each randomization group. Methods We use a graphical approach. The vertical axis is the unobserved true endpoint and the horizontal axis is the potential surrogate endpoint. Perfect correlation within each randomization group implies that, for each randomization group, potential surrogate and true endpoints are related by a straight line. In this scenario the investigator does not know the slopes or intercepts. We consider a plausible example where the slope of the line is higher for the experimental group than for the control group. Results In our example with unknown lines, a decrease in mean potential surrogate endpoints from control to experimental groups corresponds to an increase in mean true endpoint from control to experimental groups. Thus the potential surrogate endpoints give the wrong inference. Similar results hold for binary potential surrogate and true outcomes (although the notion of correlation does not apply). The potential surrogate endpointwould give the correct inference if either (i) the unknown lines for the two group coincided, which means that the distribution of true endpoint conditional on potential surrogate endpoint does not depend on treatment group, which is called the Prentice Criterion or (ii) if one could accurately predict the lines based on data from prior studies. Conclusion Perfect correlation between potential surrogate and unobserved true outcomes within randomized groups does not guarantee correct inference based on a potential surrogate endpoint. Even in early phase trials, investigators should not base conclusions on potential surrogate endpoints in which the only validation is high correlation with the true endpoint within a group. PMID:12962545

Science Teacher Candidates' Learning and Studying Strategies in the Context of Self-Regulation

ERIC Educational Resources Information Center

Yilmaz, Özkan

2017-01-01

This study investigated the students' individual study and learning strategies. Toward this purpose, open ended question form was administered to 40 university students who have enrolled department of mathematics and science education, faculty of education. Students were selected randomly in all level of class. Qualitative research method was used…

Investigating Best Practice and Effectiveness of Leadership Wisdom among Principals of Excellent Secondary School Malaysia: Perceptions of Senior Assistants

ERIC Educational Resources Information Center

Ahmad, Abdul Razaq; Salleh, Mohamad Johdi; Awang, Mohd Mahzan; Mohamad, Nazifah Alwani

2013-01-01

The aim of the current study is to investigate the practices and effectiveness of leadership wisdom among the principals of excellent secondary schools as perceived by the Senior Assistants. This research employed survey approach by using a validated questionnaire. The respondents were 417 Senior Assistants, who were randomly selected from the…

Weight Status in Iranian Children with Autism Spectrum Disorders: Investigation of Underweight, Overweight and Obesity

ERIC Educational Resources Information Center

Memari, Amir Hossein; Kordi, Ramin; Ziaee, Vahid; Mirfazeli, Fatemeh Sadat; Setoodeh, Mohammad S.

2012-01-01

The purpose of this study was to survey the weight status of children and adolescents with autism spectrum disorders (ASDs) in Iranian pupils and further to investigate the most likely associated factors such as demographics, autism severity and medications. The survey was designed to provide a random sample of 113 children and adolescents (boys =…

An Investigation of the Effects of a Graphic Organizer in an Online Serious Game on Learning Outcomes and Attitudinal Perceptions

ERIC Educational Resources Information Center

Cheon, Jongpil; Chung, Sungwon; Song, Jaeki; Kim, Yongjin

2015-01-01

A serious game, which is designed for learning purposes rather than recreational purposes, has been applied for digital game-based Learning. This study investigated the effects of graphic organizers in a serious game, "The Transistor", on learning outcomes and attitudinal perceptions. A total of 99 participants were randomly assigned to…

An Investigation into the Relationships Between Cloze Test Scores and Informal Reading Inventory Scores of Fifth Grade Pupils.

ERIC Educational Resources Information Center

Walter, Richard Barry

This study investigated the relationship between instructional level scores as determined by a cloze test and instructional level scores as determined by an informal reading inventory (IRI). Fifty male and 50 female subjects were randomly selected from the total fifth grade population of five schools chosen from a total of 22 midwestern elementary…

An Investigation of the Use of Listening Strategies and Listening Performance of Proficient and Nonproficient Language Learners

ERIC Educational Resources Information Center

Piamsai, Chatraporn

2014-01-01

This study was an attempt to investigate how proficient and non-proficient learners used listening strategies to complete a listening task. 65 third-year Chulalongkorn University Commerce and Accountancy students participated in the first stage of the quantitative data collection. 18 students were randomly selected from the group for more in depth…

DUrable polymer-based sTent CHallenge of Promus ElemEnt versus ReSolute integrity (DUTCH PEERS): rationale and study design of a randomized multicenter trial in a Dutch all-comers population.

PubMed

Tandjung, Kenneth; Basalus, Mounir W Z; Sen, Hanim; Jessurun, Gillian A J; Danse, Peter W; Stoel, Martin; Linssen, Gerard C M; Derks, Anita; van Loenhout, Ton T; Nienhuis, Mark B; Hautvast, Raymond W M; von Birgelen, Clemens

2012-04-01

Drug-eluting stents (DES) are increasingly used for the treatment of coronary artery disease. An optimized DES performance is desirable to successfully treat various challenging coronary lesions in a broad population of patients. In response to this demand, third-generation DES with an improved deliverability were developed. Promus Element (Boston Scientific, Natick, MA) and Resolute Integrity (Medtronic Vascular, Santa Rosa, CA) are 2 novel third-generation DES for which limited clinical data are available. Accordingly, we designed the current multicenter study to investigate in an all-comers population whether the clinical outcome is similar after stenting with Promus Element versus Resolute Integrity. DUTCH PEERS is a multicenter, prospective, single-blinded, randomized trial in a Dutch all-comers population. Patients with all clinical syndromes who require percutaneous coronary interventions with DES implantation are eligible. In these patients, the type of DES implanted will be randomized in a 1:1 ratio between Resolute Integrity versus Promus Element. The trial is powered based on a noninferiority hypothesis. For each stent arm, 894 patients will be enrolled, resulting in a total study population of 1,788 patients. The primary end point is the incidence of target vessel failure at 1-year follow-up. DUTCH PEERS is the first randomized multicenter trial with a head-to-head comparison of Promus Element and Resolute Integrity to investigate the safety and efficacy of these third-generation DES. Copyright © 2012 Mosby, Inc. All rights reserved.

The Effect of Improved Water Supply on Diarrhea Prevalence of Children under Five in the Volta Region of Ghana: A Cluster-Randomized Controlled Trial.

PubMed

Cha, Seungman; Kang, Douk; Tuffuor, Benedict; Lee, Gyuhong; Cho, Jungmyung; Chung, Jihye; Kim, Myongjin; Lee, Hoonsang; Lee, Jaeeun; Oh, Chunghyeon

2015-09-25

Although a number of studies have been conducted to explore the effect of water quality improvement, the majority of them have focused mainly on point-of-use water treatment, and the studies investigating the effect of improved water supply have been based on observational or inadequately randomized trials. We report the results of a matched cluster randomized trial investigating the effect of improved water supply on diarrheal prevalence of children under five living in rural areas of the Volta Region in Ghana. We compared the diarrheal prevalence of 305 children in 10 communities of intervention with 302 children in 10 matched communities with no intervention (October 2012 to February 2014). A modified Poisson regression was used to estimate the prevalence ratio. An intention-to-treat analysis was undertaken. The crude prevalence ratio of diarrhea in the intervention compared with the control communities was 0.85 (95% CI 0.74-0.97) for Krachi West, 0.96 (0.87-1.05) for Krachi East, and 0.91 (0.83-0.98) for both districts. Sanitation was adjusted for in the model to remove the bias due to residual imbalance since it was not balanced even after randomization. The adjusted prevalence ratio was 0.82 (95% CI 0.71-0.96) for Krachi West, 0.95 (0.86-1.04) for Krachi East, and 0.89 (0.82-0.97) for both districts. This study provides a basis for a better approach to water quality interventions.

The Effect of Improved Water Supply on Diarrhea Prevalence of Children under Five in the Volta Region of Ghana: A Cluster-Randomized Controlled Trial

PubMed Central

Cha, Seungman; Kang, Douk; Tuffuor, Benedict; Lee, Gyuhong; Cho, Jungmyung; Chung, Jihye; Kim, Myongjin; Lee, Hoonsang; Lee, Jaeeun; Oh, Chunghyeon

2015-01-01

Although a number of studies have been conducted to explore the effect of water quality improvement, the majority of them have focused mainly on point-of-use water treatment, and the studies investigating the effect of improved water supply have been based on observational or inadequately randomized trials. We report the results of a matched cluster randomized trial investigating the effect of improved water supply on diarrheal prevalence of children under five living in rural areas of the Volta Region in Ghana. We compared the diarrheal prevalence of 305 children in 10 communities of intervention with 302 children in 10 matched communities with no intervention (October 2012 to February 2014). A modified Poisson regression was used to estimate the prevalence ratio. An intention-to-treat analysis was undertaken. The crude prevalence ratio of diarrhea in the intervention compared with the control communities was 0.85 (95% CI 0.74–0.97) for Krachi West, 0.96 (0.87–1.05) for Krachi East, and 0.91 (0.83–0.98) for both districts. Sanitation was adjusted for in the model to remove the bias due to residual imbalance since it was not balanced even after randomization. The adjusted prevalence ratio was 0.82 (95% CI 0.71–0.96) for Krachi West, 0.95 (0.86–1.04) for Krachi East, and 0.89 (0.82–0.97) for both districts. This study provides a basis for a better approach to water quality interventions. PMID:26404337

Efficacy of a novel phosphodiesterase inhibitor, E6005, in patients with atopic dermatitis: An investigator-blinded, vehicle-controlled study.

PubMed

Ohba, Fuminori; Matsuki, Shunji; Imayama, Shuhei; Matsuguma, Kyoko; Hojo, Seiichiro; Nomoto, Maiko; Akama, Hideto

2016-10-01

Phosphodiesterase type 4 (PDE4) inhibition is a well-known anti-inflammatory mechanism. However, the clinical use of PDE4 inhibitors has been compromised by the occurrence of mechanism-associated adverse reactions, which often limit the maximum tolerated dose. To minimize systemic exposure, a topically active PDE4 inhibitor with low transdermal bioavailability could be clinically useful. The purpose of this study was to evaluate the efficacy of a novel topical PDE4 inhibitor, E6005, in patients with atopic dermatitis. This randomized, investigator-blinded, vehicle-controlled, multiple ascending dose study included 40 adult male patients with atopic dermatitis, who were randomly assigned to 10 days of treatment with either E6005 ointment (0.01, 0.03, 0.1 or 0.2%) or vehicle ointment. Of 81 patients screened, 40 who had typical lesions on their posterior trunk were randomized into the study. One patient receiving 0.03% E6005 treatment discontinued because of acute gout and one receiving vehicle treatment discontinued because of progression of atopic dermatitis. The targeted lesion severity scores decreased in a concentration-dependent manner in patients treated with E6005. This drop was significant in the 0.2% E6005 ointment treatment group (mean percent change: -54.30%, p = 0.007). E6005 ointment showed anti-inflammatory efficacy in adult patients with atopic dermatitis.

Disappointment and adherence among parents of newborns allocated to the control group: a qualitative study of a randomized clinical trial.

PubMed

Meinich Petersen, Sandra; Zoffmann, Vibeke; Kjærgaard, Jesper; Graff Stensballe, Lone; Graff Steensballe, Lone; Greisen, Gorm

2014-04-15

When a child participates in a clinical trial, informed consent has to be given by the parents. Parental motives for participation are complex, but the hope of getting a new and better treatment for the child is important. We wondered how parents react when their child is allocated to the control group of a randomized controlled trial, and how it will affect their future engagement in the trial. We included parents of newborns randomized to the control arm in the Danish Calmette study at Rigshospitalet in Copenhagen. The Calmette study is a randomized clinical trial investigating the non-specific effects of early BCG-vaccine to healthy neonates. Randomization is performed immediately after birth and parents are not blinded to the allocation. We set up a semi-structured focus group with six parents from four families. Afterwards we telephone-interviewed another 19 mothers to achieve saturation. Thematic analysis was used to identify themes across the data sets. The parents reported good understanding of the randomization process. Their most common reaction to allocation was disappointment, though relief was also seen. A model of reactions to being allocated to the control group was developed based on the participants' different positions along two continuities from 'Our participation in trial is not important' to 'Our participation in trial is important', and 'Vaccine not important to us' to 'Vaccine important to us'. Four very disappointed families had thought of getting the vaccine elsewhere, and one had actually had their child vaccinated. All parents involved in the focus group and the telephone interviews wanted to participate in the follow-ups planned for the Calmette study. This study identified an almost universal experience of disappointment among parents of newborns who were randomized to the control group, but also a broad expression of understanding and accepting the idea of randomization. The trial staff might use the model of reactions in understanding the parents' disappointment and in this way support their motives for participation. A generalized version might be applicable across randomized controlled trials at large. The Calmette study is registered in EudraCT (https://eudract.ema.europa.eu/) with trial number 2010-021979-85.

The Analysis of Completely Randomized Factorial Experiments When Observations Are Lost at Random.

ERIC Educational Resources Information Center

Hummel, Thomas J.

An investigation was conducted of the characteristics of two estimation procedures and corresponding test statistics used in the analysis of completely randomized factorial experiments when observations are lost at random. For one estimator, contrast coefficients for cell means did not involve the cell frequencies. For the other, contrast…

76 FR 80964 - Certain Dynamic Random Access Memory Devices, and Products Containing Same; Institution of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-821] Certain Dynamic Random Access Memory... importation, and the sale within the United States after importation of certain dynamic random access memory... certain dynamic random access memory devices, and products containing same that infringe one or more of...

A double-blind, randomized, placebo-controlled, parallel-group study of THC/CBD oromucosal spray in combination with the existing treatment regimen, in the relief of central neuropathic pain in patients with multiple sclerosis.

PubMed

Langford, R M; Mares, J; Novotna, A; Vachova, M; Novakova, I; Notcutt, W; Ratcliffe, S

2013-04-01

Central neuropathic pain (CNP) occurs in many multiple sclerosis (MS) patients. The provision of adequate pain relief to these patients can very difficult. Here we report the first phase III placebo-controlled study of the efficacy of the endocannabinoid system modulator delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) oromucosal spray (USAN name, nabiximols; Sativex, GW Pharmaceuticals, Salisbury, Wiltshire, UK), to alleviate CNP. Patients who had failed to gain adequate analgesia from existing medication were treated with THC/CBD spray or placebo as an add-on treatment, in a double-blind manner, for 14 weeks to investigate the efficacy of the medication in MS-induced neuropathic pain. This parallel-group phase of the study was then followed by an 18-week randomized-withdrawal study (14-week open-label treatment period plus a double-blind 4-week randomized-withdrawal phase) to investigate time to treatment failure and show maintenance of efficacy. A total of 339 patients were randomized to phase A (167 received THC/CBD spray and 172 received placebo). Of those who completed phase A, 58 entered the randomized-withdrawal phase. The primary endpoint of responder analysis at the 30 % level at week 14 of phase A of the study was not met, with 50 % of patients on THC/CBD spray classed as responders at the 30 % level compared to 45 % of patients on placebo (p = 0.234). However, an interim analysis at week 10 showed a statistically significant treatment difference in favor of THC/CBD spray at this time point (p = 0.046). During the randomized-withdrawal phase, the primary endpoint of time to treatment failure was statistically significant in favor of THC/CBD spray, with 57 % of patients receiving placebo failing treatment versus 24 % of patients from the THC/CBD spray group (p = 0.04). The mean change from baseline in Pain Numerical Rating Scale (NRS) (p = 0.028) and sleep quality NRS (p = 0.015) scores, both secondary endpoints in phase B, were also statistically significant compared to placebo, with estimated treatment differences of -0.79 and 0.99 points, respectively, in favor of THC/CBD spray treatment. The results of the current investigation were equivocal, with conflicting findings in the two phases of the study. While there were a large proportion of responders to THC/CBD spray treatment during the phase A double-blind period, the primary endpoint was not met due to a similarly large number of placebo responders. In contrast, there was a marked effect in phase B of the study, with an increased time to treatment failure in the THC/CBD spray group compared to placebo. These findings suggest that further studies are required to explore the full potential of THC/CBD spray in these patients.

Safety of Bifidobacterium animalis Subsp. Lactis (B. lactis) Strain BB-12-Supplemented Yogurt in Healthy Children.

PubMed

Tan, Tina P; Ba, Zhaoyong; Sanders, Mary E; D'Amico, Frank J; Roberts, Robert F; Smith, Keisha H; Merenstein, Daniel J

2017-02-01

Probiotics are live microorganisms that may provide health benefits to the individual when consumed in sufficient quantities. For studies conducted on health or disease endpoints on probiotics in the United States, the Food and Administration has required those studies to be conducted as investigational new drugs. This phase I, double-blinded, randomized, controlled safety study represents the first requirement of this pathway. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp. lactis (B lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of children. The secondary aim was to assess the effect of BB-12-supplemented yogurt on the gut microbiota of the children. Sixty children ages 1 to 5 years were randomly assigned to consume 4 ounces of either BB-12-supplemented yogurt or nonsupplemented control yogurt daily for 10 days. The primary outcome was to assess safety and tolerability, as determined by the number of reported adverse events. A total of 186 nonserious adverse events were reported, with no significant differences between the control and BB-12 groups. No significant changes due to probiotic treatment were observed in the gut microbiota of the study cohort. BB-12-supplemented yogurt is safe and well-tolerated when consumed by healthy children. The present study will form the basis for future randomized clinical trials investigating the potential effects of BB-12-supplemented yogurt in different disease states.

Non-randomized response model for sensitive survey with noncompliance.

PubMed

Wu, Qin; Tang, Man-Lai

2016-12-01

Collecting representative data on sensitive issues has long been problematic and challenging in public health prevalence investigation (e.g. non-suicidal self-injury), medical research (e.g. drug habits), social issue studies (e.g. history of child abuse), and their interdisciplinary studies (e.g. premarital sexual intercourse). Alternative data collection techniques that can be adopted to study sensitive questions validly become more important and necessary. As an alternative to the famous Warner randomized response model, non-randomized response triangular model has recently been developed to encourage participants to provide truthful responses in surveys involving sensitive questions. Unfortunately, both randomized and non-randomized response models could underestimate the proportion of subjects with the sensitive characteristic as some respondents do not believe that these techniques can protect their anonymity. As a result, some authors hypothesized that lack of trust and noncompliance should be highest among those who have the most to lose and the least to use for the anonymity provided by using these techniques. Some researchers noticed the existence of noncompliance and proposed new models to measure noncompliance in order to get reliable information. However, all proposed methods were based on randomized response models which require randomizing devices, restrict the survey to only face-to-face interview and are lack of reproductivity. Taking the noncompliance into consideration, we introduce new non-randomized response techniques in which no covariate is required. Asymptotic properties of the proposed estimates for sensitive characteristic as well as noncompliance probabilities are developed. Our proposed techniques are empirically shown to yield accurate estimates for both sensitive and noncompliance probabilities. A real example about premarital sex among university students is used to demonstrate our methodologies. © The Author(s) 2014.

An educational intervention on drug interactions and contraceptive options for epilepsy patients: a pilot randomized controlled trial.

PubMed

Mody, Sheila K; Haunschild, Carolyn; Farala, John Paul; Honerkamp-Smith, Gordon; Hur, Vivian; Kansal, Leena

2016-01-01

This pilot study investigates whether an educational handout could increase short-term information retention about drug interactions between antiepileptic drugs (AEDs) and hormonal contraceptives among female epilepsy patients of reproductive age. This is a pilot randomized controlled trial of an educational intervention among reproductive-age women with epilepsy in an academic neurology clinic. Investigators measured knowledge before and after participants received either usual care or the educational handout. The 10-question test assessed increased knowledge of which AEDs affected efficacy of certain hormonal contraceptives and was assessed by calculating the improvement in score between the pretest and posttest. The educational handout included the names of AEDs that have drug interactions with certain contraceptives and the efficacy of the contraceptives. A total of 42 epilepsy patients participated in this study. Fourteen participants were taking AEDs that are enzyme p450 inducers and 13 participants were taking Lamotrigine. Twenty women were randomized to receive the educational handout and 22 women were randomized to usual care. We found no statistical difference in the groups with regard to age, ethnicity or level of education. We found a significantly higher improvement in quiz scores in the educational handout group (3.65 point increase) compared to the usual care group (0.68 point increase) as calculated by the Student's two-sample t test (p<.001). An educational handout on drug interactions and contraceptives resulted in increased short-term information retention on this topic among reproductive-age female epilepsy patients. This pilot study highlights the need for further larger studies to evaluate the impact of educational interventions on improving patient knowledge about the drug interaction of AEDs and hormonal contraceptives. Copyright © 2016. Published by Elsevier Inc.

Effectiveness and Cost-Effectiveness of Different Weekly Frequencies of Pilates for Chronic Low Back Pain: Randomized Controlled Trial.

PubMed

Miyamoto, Gisela Cristiane; Moura, Katherinne Ferro; Franco, Yuri Rafael dos Santos; Oliveira, Naiane Teixeira Bastos de; Amaral, Diego Diulgeroglo Vicco; Branco, Amanda Nery Castelo; Silva, Maria Liliane da; Lin, Christine; Cabral, Cristina Maria Nunes

2016-03-01

The Pilates method has been recommended to patients with low back pain, but the evidence on effectiveness is inconclusive. In addition, there is still no evidence for the cost-effectiveness of this method or for the ideal number of sessions to achieve the highest effectiveness. The aim of this study will be to investigate the effectiveness and cost-effectiveness of the Pilates method with different weekly frequencies in the treatment of patients with nonspecific low back pain. This is a randomized controlled trial with blinded assessor. This study will be conducted at a physical therapy clinic in São Paulo, Brazil. Two hundred ninety-six patients with nonspecific low back pain between the ages of 18 and 80 years will be assessed and randomly allocated to 4 groups (n=74 patients per group). All groups will receive an educational booklet. The booklet group will not receive additional exercises. Pilates group 1 will follow a Pilates-based program once a week, Pilates group 2 will follow the same program twice a week, and Pilates group 3 will follow the same program 3 times a week. The intervention will last 6 weeks. A blinded assessor will evaluate pain, quality-adjusted life-years, general and specific disability, kinesiophobia, pain catastrophizing, and global perceived effect 6 weeks, 6 months, and 12 months after randomization. Therapists and patients will not be blinded. This will be the first study to investigate different weekly frequencies of treatment sessions for nonspecific low back pain. The results of this study will contribute to a better definition of treatment programs for this population. © 2016 American Physical Therapy Association.

ADAPTIVE MATCHING IN RANDOMIZED TRIALS AND OBSERVATIONAL STUDIES

PubMed Central

van der Laan, Mark J.; Balzer, Laura B.; Petersen, Maya L.

2014-01-01

SUMMARY In many randomized and observational studies the allocation of treatment among a sample of n independent and identically distributed units is a function of the covariates of all sampled units. As a result, the treatment labels among the units are possibly dependent, complicating estimation and posing challenges for statistical inference. For example, cluster randomized trials frequently sample communities from some target population, construct matched pairs of communities from those included in the sample based on some metric of similarity in baseline community characteristics, and then randomly allocate a treatment and a control intervention within each matched pair. In this case, the observed data can neither be represented as the realization of n independent random variables, nor, contrary to current practice, as the realization of n/2 independent random variables (treating the matched pair as the independent sampling unit). In this paper we study estimation of the average causal effect of a treatment under experimental designs in which treatment allocation potentially depends on the pre-intervention covariates of all units included in the sample. We define efficient targeted minimum loss based estimators for this general design, present a theorem that establishes the desired asymptotic normality of these estimators and allows for asymptotically valid statistical inference, and discuss implementation of these estimators. We further investigate the relative asymptotic efficiency of this design compared with a design in which unit-specific treatment assignment depends only on the units’ covariates. Our findings have practical implications for the optimal design and analysis of pair matched cluster randomized trials, as well as for observational studies in which treatment decisions may depend on characteristics of the entire sample. PMID:25097298

Severity of Organized Item Theft in Computerized Adaptive Testing: A Simulation Study

ERIC Educational Resources Information Center

Yi, Qing; Zhang, Jinming; Chang, Hua-Hua

2008-01-01

Criteria had been proposed for assessing the severity of possible test security violations for computerized tests with high-stakes outcomes. However, these criteria resulted from theoretical derivations that assumed uniformly randomized item selection. This study investigated potential damage caused by organized item theft in computerized adaptive…

Drills vs. Games--Any Differences? A Pilot Study.

ERIC Educational Resources Information Center

McMullen, David W.

This study investigated the effect of informational, drill, and game format computer-assisted instruction (CAI) on the achievement, retention, and attitude toward instruction of sixth-grade science students (N=37). An informational CAI lesson on Halley's Comet was administered to three randomly selected groups of sixth-grade students. A CAI drill…

Mathematical Intelligence and Mathematical Creativity: A Causal Relationship

ERIC Educational Resources Information Center

Tyagi, Tarun Kumar

2017-01-01

This study investigated the causal relationship between mathematical creativity and mathematical intelligence. Four hundred thirty-nine 8th-grade students, age ranged from 11 to 14 years, were included in the sample of this study by random cluster technique on which mathematical creativity and Hindi adaptation of mathematical intelligence test…

Effectiveness of Interactive Video to Teach CPR Theory and Skills.

ERIC Educational Resources Information Center

Lyness, Ann L.

This study investigated whether an interactive video system of instruction taught cardiopulmonary resuscitation (CPR) as effectively as traditional instruction. Using standards of the American Heart Association, the study was designed with two randomized groups to be taught either by live instruction or by interactive video. Subjects were 100…

Negative Particles and Morphemes in Jordanian Arabic Dialects

ERIC Educational Resources Information Center

Mrayat, Ahmad

2015-01-01

This paper aims at investigating the negative particles and morphemes in three main Jordanian dialects (Urban, Rural and Bedouin). This quantitative and qualitative study includes 30 teachers from different disciplines who use these dialects. The sample of the study was selected randomly. The research used two research instruments, a checklist and…

Authentic Leadership and Altruism: The Mediating Role of Meaningfulness

ERIC Educational Resources Information Center

Sagnak, Mesut; Kuruöz, Mehmet

2017-01-01

The purpose of this study was to investigate the mediating effects of meaningfulness on the relationship between authentic leadership and altruistic behavior. The participants consisted of 356 teachers randomly selected from 14 primary and secondary schools in Nigde. Three different instruments were used in this study. The scales were translated…

Supporting Students' Knowledge Transfer in Modeling Activities

ERIC Educational Resources Information Center

Piksööt, Jaanika; Sarapuu, Tago

2014-01-01

This study investigates ways to enhance secondary school students' knowledge transfer in complex science domains by implementing question prompts. Two samples of students applied two web-based models to study molecular genetics--the model of genetic code (n = 258) and translation (n = 245). For each model, the samples were randomly divided into…

Resource Utilisation and Curriculum Implementation in Community Colleges in Kenya

ERIC Educational Resources Information Center

Kigwilu, Peter Changilwa; Akala, Winston Jumba

2017-01-01

The study investigated how Catholic-sponsored community colleges in Nairobi utilise the existing physical facilities and teaching and learning resources for effective implementation of Artisan and Craft curricula. The study adopted a mixed methods research design. Proportional stratified random sampling was used to sample 172 students and 18…

Emotional, Motivational and Interpersonal Responsiveness of Children with Autism in Improvisational Music Therapy

ERIC Educational Resources Information Center

Kim, Jinah; Wigram, Tony; Gold, Christian

2009-01-01

Through behavioural analysis, this study investigated the social-motivational aspects of musical interaction between the child and the therapist in improvisational music therapy by measuring emotional, motivational and interpersonal responsiveness in children with autism during joint engagement episodes. The randomized controlled study (n = 10)…

Monolingual or Bilingual Intervention for Primary Language Impairment? A Randomized Control Trial

ERIC Educational Resources Information Center

Thordardottir, Elin; Cloutier, Geneviève; Ménard, Suzanne; Pelland-Blais, Elaine; Rvachew, Susan

2015-01-01

Purpose: This study investigated the clinical effectiveness of monolingual versus bilingual language intervention, the latter involving speech-language pathologist-parent collaboration. The study focuses on methods that are currently being recommended and that are feasible within current clinical contexts. Method: Bilingual children with primary…

A randomized controlled trial of intranasal ketamine in migraine with prolonged aura.

PubMed

Afridi, Shazia K; Giffin, Nicola J; Kaube, Holger; Goadsby, Peter J

2013-02-12

The aim of our study was to test the hypothesis that ketamine would affect aura in a randomized controlled double-blind trial, and thus to provide direct evidence for the role of glutamatergic transmission in human aura. We performed a double-blinded, randomized parallel-group controlled study investigating the effect of 25 mg intranasal ketamine on migraine with prolonged aura in 30 migraineurs using 2 mg intranasal midazolam as an active control. Each subject recorded data from 3 episodes of migraine. Eighteen subjects completed the study. Ketamine reduced the severity (p = 0.032) but not duration of aura in this group, whereas midazolam had no effect. These data provide translational evidence for the potential importance of glutamatergic mechanisms in migraine aura and offer a pharmacologic parallel between animal experimental work on cortical spreading depression and the clinical problem. This study provides class III evidence that intranasal ketamine is effective in reducing aura severity in patients with migraine with prolonged aura.

Are glucose levels, glucose variability and autonomic control influenced by inspiratory muscle exercise in patients with type 2 diabetes? Study protocol for a randomized controlled trial.

PubMed

Schein, Aso; Correa, Aps; Casali, Karina Rabello; Schaan, Beatriz D

2016-01-20

Physical exercise reduces glucose levels and glucose variability in patients with type 2 diabetes. Acute inspiratory muscle exercise has been shown to reduce these parameters in a small group of patients with type 2 diabetes, but these results have yet to be confirmed in a well-designed study. The aim of this study is to investigate the effect of acute inspiratory muscle exercise on glucose levels, glucose variability, and cardiovascular autonomic function in patients with type 2 diabetes. This study will use a randomized clinical trial crossover design. A total of 14 subjects will be recruited and randomly allocated to two groups to perform acute inspiratory muscle loading at 2 % of maximal inspiratory pressure (PImax, placebo load) or 60 % of PImax (experimental load). Inspiratory muscle training could be a novel exercise modality to be used to decrease glucose levels and glucose variability. ClinicalTrials.gov NCT02292810 .

Using cross-correlations of random wavefields for surface waves tomography and structural health monitoring.

NASA Astrophysics Data System (ADS)

Sabra, K.

2006-12-01

The random nature of noise and scattered fields tends to suggest limited utility. Indeed, seismic or acoustic fields from random sources or scatterers are often considered to be incoherent, but there is some coherence between two sensors that receive signals from the same individual source or scatterer. An estimate of the Green's function (or impulse response) between two points can be obtained from the cross-correlation of random wavefields recorded at these two points. Recent theoretical and experimental studies in ultrasonics, underwater acoustics, structural monitoring and seismology have investigated this technique in various environments and frequency ranges. These results provide a means for passive imaging using only the random wavefields, without the use of active sources. The coherent wavefronts emerge from a correlation process that accumulates contributions over time from random sources whose propagation paths pass through both receivers. Results will be presented from experiments using ambient noise cross-correlations for the following applications: 1) passive surface waves tomography from ocean microseisms and 2) structural health monitoring of marine and airborne structures embedded in turbulent flow.

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

Maternal Opioid Treatment: Human Experimental Research (MOTHER) – Approach, Issues, and Lessons Learned

PubMed Central

Jones, Hendrée E.; Fischer, Gabriele; Heil, Sarah H.; Kaltenbach, Karol; Martin, Peter R.; Coyle, Mara G.; Selby, Peter; Stine, Susan M.; O’Grady, Kevin E.; Arria, Amelia M.

2015-01-01

Aims The Maternal Opioid Treatment: Human Experimental Research (MOTHER) project, an eight-site randomized, double-blind, double-dummy, flexible-dosing, parallel-group clinical trial is described. This study is the most current – and single most comprehensive – research effort to investigate the safety and efficacy of maternal and prenatal exposure to methadone and buprenorphine. Methods The MOTHER study design is outlined, and its basic features are presented. Conclusions At least seven important lessons have been learned from the MOTHER study: (1) an interdisciplinary focus improves the design and methods of a randomized clinical trial; (2) multiple sites in a clinical trial present continuing challenges to the investigative team due to variations in recruitment goals, patient populations, and hospital practices that in turn differentially impact recruitment rates, treatment compliance, and attrition; (3) study design and protocols must be flexible in order to meet the unforeseen demands of both research and clinical management; (4) staff turnover needs to be addressed with a proactive focus on both hiring and training; (5) the implementation of a protocol for the treatment of a particular disorder may identify important ancillary clinical issues worthy of investigation; (6) timely tracking of data in a multi-site trial is both demanding and unforgiving; and, (7) complex multi-site trials pose unanticipated challenges that complicate the choice of statistical methods, thereby placing added demands on investigators to effectively communicate their results. PMID:23106924

Run-Reversal Equilibrium for Clinical Trial Randomization

PubMed Central

Grant, William C.

2015-01-01

In this paper, we describe a new restricted randomization method called run-reversal equilibrium (RRE), which is a Nash equilibrium of a game where (1) the clinical trial statistician chooses a sequence of medical treatments, and (2) clinical investigators make treatment predictions. RRE randomization counteracts how each investigator could observe treatment histories in order to forecast upcoming treatments. Computation of a run-reversal equilibrium reflects how the treatment history at a particular site is imperfectly correlated with the treatment imbalance for the overall trial. An attractive feature of RRE randomization is that treatment imbalance follows a random walk at each site, while treatment balance is tightly constrained and regularly restored for the overall trial. Less predictable and therefore more scientifically valid experiments can be facilitated by run-reversal equilibrium for multi-site clinical trials. PMID:26079608

Network meta-analysis of disconnected networks: How dangerous are random baseline treatment effects?

PubMed

Béliveau, Audrey; Goring, Sarah; Platt, Robert W; Gustafson, Paul

2017-12-01

In network meta-analysis, the use of fixed baseline treatment effects (a priori independent) in a contrast-based approach is regularly preferred to the use of random baseline treatment effects (a priori dependent). That is because, often, there is not a need to model baseline treatment effects, which carry the risk of model misspecification. However, in disconnected networks, fixed baseline treatment effects do not work (unless extra assumptions are made), as there is not enough information in the data to update the prior distribution on the contrasts between disconnected treatments. In this paper, we investigate to what extent the use of random baseline treatment effects is dangerous in disconnected networks. We take 2 publicly available datasets of connected networks and disconnect them in multiple ways. We then compare the results of treatment comparisons obtained from a Bayesian contrast-based analysis of each disconnected network using random normally distributed and exchangeable baseline treatment effects to those obtained from a Bayesian contrast-based analysis of their initial connected network using fixed baseline treatment effects. For the 2 datasets considered, we found that the use of random baseline treatment effects in disconnected networks was appropriate. Because those datasets were not cherry-picked, there should be other disconnected networks that would benefit from being analyzed using random baseline treatment effects. However, there is also a risk for the normality and exchangeability assumption to be inappropriate in other datasets even though we have not observed this situation in our case study. We provide code, so other datasets can be investigated. Copyright © 2017 John Wiley & Sons, Ltd.

Predictors of study completion and withdrawal in a randomized clinical trial of a pediatric diabetes adherence intervention.

PubMed

Driscoll, Kimberly A; Killian, Michael; Johnson, Suzanne Bennett; Silverstein, Janet H; Deeb, Larry C

2009-05-01

Loss of participants in randomized clinical trials threatens the validity of study findings. The purpose of this study was to determine pre-randomization predictors of study completion status throughout the course of a randomized clinical trial involving young children with type 1 diabetes and their primary caregivers. An intervention to improve adherence to the diabetes treatment regimen was delivered as part of the child's regular 3-month diabetes clinic visit. The study protocol involved 7 clinic visits across 18 months for the Immediate Treatment group and 9 clinic visits across 24 months for the Delayed Treatment group. Among those who completed the study and regardless of treatment group, participants were categorized into two groups: On-Time Completers (n=41) and Late Completers (n=39). Demographic, disease, and psychosocial characteristics of children and their primary caregivers measured prior to study randomization were tested for their association with the participants' completion status (i.e., On-Time Completers, Late Completers, or Withdrawals). Of the 108 participants, 28 (25.9%) withdrew and 80 (74.1%) completed the study. On-Time Completers (i.e., study completed within 4 months of expected date) were more likely to have private insurance and primary caregivers with some college education. Late Completers (i.e., study completion took longer than 4 months) were more likely to be boys and to have primary caregivers who reported mild to moderate levels of depression. Children who subsequently withdrew from the study reported poorer diabetes-related quality of life and poorer school-related quality of life at study inception and were more likely to have primary caregivers who did not work outside the home. Pre-randomization screening of participants on both demographic and psychological variables may help identify those at greatest risk for study withdrawal or poor study protocol adherence, permitting the investigators to develop retention strategies aimed at this high-risk group.

Subgroup Analysis of Trials Is Rarely Easy (SATIRE): a study protocol for a systematic review to characterize the analysis, reporting, and claim of subgroup effects in randomized trials.

PubMed

Sun, Xin; Briel, Matthias; Busse, Jason W; Akl, Elie A; You, John J; Mejza, Filip; Bala, Malgorzata; Diaz-Granados, Natalia; Bassler, Dirk; Mertz, Dominik; Srinathan, Sadeesh K; Vandvik, Per Olav; Malaga, German; Alshurafa, Mohamed; Dahm, Philipp; Alonso-Coello, Pablo; Heels-Ansdell, Diane M; Bhatnagar, Neera; Johnston, Bradley C; Wang, Li; Walter, Stephen D; Altman, Douglas G; Guyatt, Gordon H

2009-11-09

Subgroup analyses in randomized trials examine whether effects of interventions differ between subgroups of study populations according to characteristics of patients or interventions. However, findings from subgroup analyses may be misleading, potentially resulting in suboptimal clinical and health decision making. Few studies have investigated the reporting and conduct of subgroup analyses and a number of important questions remain unanswered. The objectives of this study are: 1) to describe the reporting of subgroup analyses and claims of subgroup effects in randomized controlled trials, 2) to assess study characteristics associated with reporting of subgroup analyses and with claims of subgroup effects, and 3) to examine the analysis, and interpretation of subgroup effects for each study's primary outcome. We will conduct a systematic review of 464 randomized controlled human trials published in 2007 in the 118 Core Clinical Journals defined by the National Library of Medicine. We will randomly select journal articles, stratified in a 1:1 ratio by higher impact versus lower impact journals. According to 2007 ISI total citations, we consider the New England Journal of Medicine, JAMA, Lancet, Annals of Internal Medicine, and BMJ as higher impact journals. Teams of two reviewers will independently screen full texts of reports for eligibility, and abstract data, using standardized, pilot-tested extraction forms. We will conduct univariable and multivariable logistic regression analyses to examine the association of pre-specified study characteristics with reporting of subgroup analyses and with claims of subgroup effects for the primary and any other outcomes. A clear understanding of subgroup analyses, as currently conducted and reported in published randomized controlled trials, will reveal both strengths and weaknesses of this practice. Our findings will contribute to a set of recommendations to optimize the conduct and reporting of subgroup analyses, and claim and interpretation of subgroup effects in randomized trials.

Subgroup Analysis of Trials Is Rarely Easy (SATIRE): a study protocol for a systematic review to characterize the analysis, reporting, and claim of subgroup effects in randomized trials

PubMed Central

Sun, Xin; Briel, Matthias; Busse, Jason W; Akl, Elie A; You, John J; Mejza, Filip; Bala, Malgorzata; Diaz-Granados, Natalia; Bassler, Dirk; Mertz, Dominik; Srinathan, Sadeesh K; Vandvik, Per Olav; Malaga, German; Alshurafa, Mohamed; Dahm, Philipp; Alonso-Coello, Pablo; Heels-Ansdell, Diane M; Bhatnagar, Neera; Johnston, Bradley C; Wang, Li; Walter, Stephen D; Altman, Douglas G; Guyatt, Gordon H

2009-01-01

Background Subgroup analyses in randomized trials examine whether effects of interventions differ between subgroups of study populations according to characteristics of patients or interventions. However, findings from subgroup analyses may be misleading, potentially resulting in suboptimal clinical and health decision making. Few studies have investigated the reporting and conduct of subgroup analyses and a number of important questions remain unanswered. The objectives of this study are: 1) to describe the reporting of subgroup analyses and claims of subgroup effects in randomized controlled trials, 2) to assess study characteristics associated with reporting of subgroup analyses and with claims of subgroup effects, and 3) to examine the analysis, and interpretation of subgroup effects for each study's primary outcome. Methods We will conduct a systematic review of 464 randomized controlled human trials published in 2007 in the 118 Core Clinical Journals defined by the National Library of Medicine. We will randomly select journal articles, stratified in a 1:1 ratio by higher impact versus lower impact journals. According to 2007 ISI total citations, we consider the New England Journal of Medicine, JAMA, Lancet, Annals of Internal Medicine, and BMJ as higher impact journals. Teams of two reviewers will independently screen full texts of reports for eligibility, and abstract data, using standardized, pilot-tested extraction forms. We will conduct univariable and multivariable logistic regression analyses to examine the association of pre-specified study characteristics with reporting of subgroup analyses and with claims of subgroup effects for the primary and any other outcomes. Discussion A clear understanding of subgroup analyses, as currently conducted and reported in published randomized controlled trials, will reveal both strengths and weaknesses of this practice. Our findings will contribute to a set of recommendations to optimize the conduct and reporting of subgroup analyses, and claim and interpretation of subgroup effects in randomized trials. PMID:19900273

The effects of the one-step replica symmetry breaking on the Sherrington-Kirkpatrick spin glass model in the presence of random field with a joint Gaussian probability density function for the exchange interactions and random fields

NASA Astrophysics Data System (ADS)

Hadjiagapiou, Ioannis A.; Velonakis, Ioannis N.

2018-07-01

The Sherrington-Kirkpatrick Ising spin glass model, in the presence of a random magnetic field, is investigated within the framework of the one-step replica symmetry breaking. The two random variables (exchange integral interaction Jij and random magnetic field hi) are drawn from a joint Gaussian probability density function characterized by a correlation coefficient ρ, assuming positive and negative values. The thermodynamic properties, the three different phase diagrams and system's parameters are computed with respect to the natural parameters of the joint Gaussian probability density function at non-zero and zero temperatures. The low temperature negative entropy controversy, a result of the replica symmetry approach, has been partly remedied in the current study, leading to a less negative result. In addition, the present system possesses two successive spin glass phase transitions with characteristic temperatures.

Confidence intervals for a difference between lognormal means in cluster randomization trials.

PubMed

Poirier, Julia; Zou, G Y; Koval, John

2017-04-01

Cluster randomization trials, in which intact social units are randomized to different interventions, have become popular in the last 25 years. Outcomes from these trials in many cases are positively skewed, following approximately lognormal distributions. When inference is focused on the difference between treatment arm arithmetic means, existent confidence interval procedures either make restricting assumptions or are complex to implement. We approach this problem by assuming log-transformed outcomes from each treatment arm follow a one-way random effects model. The treatment arm means are functions of multiple parameters for which separate confidence intervals are readily available, suggesting that the method of variance estimates recovery may be applied to obtain closed-form confidence intervals. A simulation study showed that this simple approach performs well in small sample sizes in terms of empirical coverage, relatively balanced tail errors, and interval widths as compared to existing methods. The methods are illustrated using data arising from a cluster randomization trial investigating a critical pathway for the treatment of community acquired pneumonia.

Single-mode SOA-based 1kHz-linewidth dual-wavelength random fiber laser.

PubMed

Xu, Yanping; Zhang, Liang; Chen, Liang; Bao, Xiaoyi

2017-07-10

Narrow-linewidth multi-wavelength fiber lasers are of significant interests for fiber-optic sensors, spectroscopy, optical communications, and microwave generation. A novel narrow-linewidth dual-wavelength random fiber laser with single-mode operation, based on the semiconductor optical amplifier (SOA) gain, is achieved in this work for the first time, to the best of our knowledge. A simplified theoretical model is established to characterize such kind of random fiber laser. The inhomogeneous gain in SOA mitigates the mode competition significantly and alleviates the laser instability, which are frequently encountered in multi-wavelength fiber lasers with Erbium-doped fiber gain. The enhanced random distributed feedback from a 5km non-uniform fiber provides coherent feedback, acting as mode selection element to ensure single-mode operation with narrow linewidth of ~1kHz. The laser noises are also comprehensively investigated and studied, showing the improvements of the proposed random fiber laser with suppressed intensity and frequency noises.

Design of a cluster-randomized minority recruitment trial: RECRUIT.

PubMed

Tilley, Barbara C; Mainous, Arch G; Smith, Daniel W; McKee, M Diane; Amorrortu, Rossybelle P; Alvidrez, Jennifer; Diaz, Vanessa; Ford, Marvella E; Fernandez, Maria E; Hauser, Robert A; Singer, Carlos; Landa, Veronica; Trevino, Aron; DeSantis, Stacia M; Zhang, Yefei; Daniels, Elvan; Tabor, Derrick; Vernon, Sally W

2017-06-01

Racial/ethnic minority groups remain underrepresented in clinical trials. Many strategies to increase minority recruitment focus on minority communities and emphasize common diseases such as hypertension. Scant literature focuses on minority recruitment to trials of less common conditions, often conducted in specialty clinics and dependent on physician referrals. We identified trust/mistrust of specialist physician investigators and institutions conducting medical research and consequent participant reluctance to participate in clinical trials as key-shared barriers across racial/ethnic groups. We developed a trust-based continuous quality improvement intervention to build trust between specialist physician investigators and community minority-serving physicians and ultimately potential trial participants. To avoid the inherent biases of non-randomized studies, we evaluated the intervention in the national Randomized Recruitment Intervention Trial (RECRUIT). This report presents the design of RECRUIT. Specialty clinic follow-up continues through April 2017. We hypothesized that specialist physician investigators and coordinators trained in the trust-based continuous quality improvement intervention would enroll a greater proportion of minority participants in their specialty clinics than specialist physician investigators in control specialty clinics. Specialty clinic was the unit of randomization. Using continuous quality improvement, the specialist physician investigators and coordinators tailored recruitment approaches to their specialty clinic characteristics and populations. Primary analyses were adjusted for clustering by specialty clinic within parent trial and matching covariates. RECRUIT was implemented in four multi-site clinical trials (parent trials) supported by three National Institutes of Health institutes and included 50 associated specialty clinics from these parent trials. Using current data, we have 88% power or greater to detect a 0.15 or greater difference from the currently observed control proportion adjusting for clustering. We detected no differences in baseline matching criteria between intervention and control specialty clinics (all p values > 0.17). RECRUIT was the first multi-site randomized control trial to examine the effectiveness of a trust-based continuous quality improvement intervention to increase minority recruitment into clinical trials. RECRUIT's innovations included its focus on building trust between specialist investigators and minority-serving physicians, the use of continuous quality improvement to tailor the intervention to each specialty clinic's specific racial/ethnic populations and barriers to minority recruitment, and the use of specialty clinics from more than one parent multi-site trial to increase generalizability. The effectiveness of the RECRUIT intervention will be determined after the completion of trial data collection and planned analyses.

A new approach in the first-line treatment of bacterial and mycotic vulvovaginitis with topical lipohydroperoxides and glycyrrhetic acid: a comparative study.

PubMed

Mainini, G; Rotondi, M; Scaffa, C

2011-01-01

PURPOSE OF INVESTIGATIONS: The aim of this randomized controlled trial was to evaluate efficacy and tolerability of a new association of lipohydroperoxides and glycyrrhetic acid on topical treatment of bacterial and mycotic vulvovaginitis. One hundred consecutive patients with bacterial or mycotic vulvovaginitis were randomly assigned to a study group treated with vaginal lipohydroperoxides and a derivative of glycyrrhetic acid for three days (n = 50), and a control group using vaginal antibacterial metronidazole (500 mg) or antimycotic econazole (150 mg) for six days (n = 50). A clinical and microbiological response was achieved in 80.4% and 88.9% in investigational and control group, respectively (p > 0.05). Compared to traditional antimicrobial drugs, the effect appears to be faster and safer, even if not significantly. The 6-month recurrence rate was 7.7% and 5.6% in the investigational and control group, respectively. Topical medication based on lipohydroperoxides and glycyrrhetic acid showed a clinical and microbiological efficacy in the first-line treatment of bacterial and mycotic vulvovaginitis, comparable to conventional drugs.

Synchronization and Inter-Layer Interactions of Noise-Driven Neural Networks

PubMed Central

Yuniati, Anis; Mai, Te-Lun; Chen, Chi-Ming

2017-01-01

In this study, we used the Hodgkin-Huxley (HH) model of neurons to investigate the phase diagram of a developing single-layer neural network and that of a network consisting of two weakly coupled neural layers. These networks are noise driven and learn through the spike-timing-dependent plasticity (STDP) or the inverse STDP rules. We described how these networks transited from a non-synchronous background activity state (BAS) to a synchronous firing state (SFS) by varying the network connectivity and the learning efficacy. In particular, we studied the interaction between a SFS layer and a BAS layer, and investigated how synchronous firing dynamics was induced in the BAS layer. We further investigated the effect of the inter-layer interaction on a BAS to SFS repair mechanism by considering three types of neuron positioning (random, grid, and lognormal distributions) and two types of inter-layer connections (random and preferential connections). Among these scenarios, we concluded that the repair mechanism has the largest effect for a network with the lognormal neuron positioning and the preferential inter-layer connections. PMID:28197088

Synchronization and Inter-Layer Interactions of Noise-Driven Neural Networks.

PubMed

Yuniati, Anis; Mai, Te-Lun; Chen, Chi-Ming

2017-01-01

In this study, we used the Hodgkin-Huxley (HH) model of neurons to investigate the phase diagram of a developing single-layer neural network and that of a network consisting of two weakly coupled neural layers. These networks are noise driven and learn through the spike-timing-dependent plasticity (STDP) or the inverse STDP rules. We described how these networks transited from a non-synchronous background activity state (BAS) to a synchronous firing state (SFS) by varying the network connectivity and the learning efficacy. In particular, we studied the interaction between a SFS layer and a BAS layer, and investigated how synchronous firing dynamics was induced in the BAS layer. We further investigated the effect of the inter-layer interaction on a BAS to SFS repair mechanism by considering three types of neuron positioning (random, grid, and lognormal distributions) and two types of inter-layer connections (random and preferential connections). Among these scenarios, we concluded that the repair mechanism has the largest effect for a network with the lognormal neuron positioning and the preferential inter-layer connections.

A randomized, placebo-controlled, double-blind study to evaluate the efficacy of a citrus bioflavanoid blend in the treatment of senile purpura.

PubMed

Berlin, Joshua M; Eisenberg, David P; Berlin, Mindy B; Sarro, Robert A; Leeman, Douglas R; Fein, Howard

2011-07-01

Senile purpura is a common, chronic skin condition affecting more than 10 percent of individuals over the age of 50. Despite being a benign condition, the continual development of purpura lesions in afflicted patients is frequently a source of significant visual and social concern. To date, there are no known effective treatments for this condition. To evaluate the efficacy of a novel nutraceutical citrus bioflavonoid blend in improving the skin's appearance in patients with senile purpura. A six-week, randomized, multicenter, placebo-controlled, double-blind study was conducted to determine whether a uniquely formulated, oral citrus bioflavonoid supplement could treat active lesions of senile purpura while preventing new lesions from arising. Seventy patients with senile purpura were enrolled and 67 completed the study. Subjects were randomized into two groups receiving either a citrus bioflavonoid blend or placebo medication, which was taken orally twice daily for six weeks. Clinical evaluations were performed by blinded investigators at two locations. A statistically significant reduction in the number of new purpura lesions in the skin area undergoing clinical study was documented. At the end of six weeks, the citrus bioflavonoid blend treated group showed a 50 percent reduction in purpura lesions from baseline. Patient self-assessment of the effectiveness of the medication echoed the results of an investigator global assessment with a statistically significant improvement in the skin's appearance noted by the patients receiving the active medication. No adverse effects were noted by either the patients or investigators. This new treatment appears to both safely and effectively diminish skin bruising in patients with senile purpura.

Intraclass correlation estimates for cancer screening outcomes: estimates and applications in the design of group-randomized cancer screening studies.

PubMed

Hade, Erinn M; Murray, David M; Pennell, Michael L; Rhoda, Dale; Paskett, Electra D; Champion, Victoria L; Crabtree, Benjamin F; Dietrich, Allen; Dignan, Mark B; Farmer, Melissa; Fenton, Joshua J; Flocke, Susan; Hiatt, Robert A; Hudson, Shawna V; Mitchell, Michael; Monahan, Patrick; Shariff-Marco, Salma; Slone, Stacey L; Stange, Kurt; Stewart, Susan L; Strickland, Pamela A Ohman

2010-01-01

Screening has become one of our best tools for early detection and prevention of cancer. The group-randomized trial is the most rigorous experimental design for evaluating multilevel interventions. However, identifying the proper sample size for a group-randomized trial requires reliable estimates of intraclass correlation (ICC) for screening outcomes, which are not available to researchers. We present crude and adjusted ICC estimates for cancer screening outcomes for various levels of aggregation (physician, clinic, and county) and provide an example of how these ICC estimates may be used in the design of a future trial. Investigators working in the area of cancer screening were contacted and asked to provide crude and adjusted ICC estimates using the analysis of variance method estimator. Of the 29 investigators identified, estimates were obtained from 10 investigators who had relevant data. ICC estimates were calculated from 13 different studies, with more than half of the studies collecting information on colorectal screening. In the majority of cases, ICC estimates could be adjusted for age, education, and other demographic characteristics, leading to a reduction in the ICC. ICC estimates varied considerably by cancer site and level of aggregation of the groups. Previously, only two articles had published ICCs for cancer screening outcomes. We have complied more than 130 crude and adjusted ICC estimates covering breast, cervical, colon, and prostate screening and have detailed them by level of aggregation, screening measure, and study characteristics. We have also demonstrated their use in planning a future trial and the need for the evaluation of the proposed interval estimator for binary outcomes under conditions typically seen in GRTs.

Corneal wound healing after superficial foreign body injury: vitamin A and dexpanthenol versus a calf blood extract. A randomized double-blind study.

PubMed

Egger, S F; Huber-Spitzy, V; Alzner, E; Scholda, C; Vecsei, V P

1999-01-01

A prospective randomized double-blind clinical study was performed to investigate corneal wound healing after treatment either with an eye gel containing calf blood extract or an eye ointment containing vitamin A and dexpanthenol. A total of 54 outpatients were included in this study, all treated for corneal foreign body injury. The size of the corneal lesions was measured by planimetry on days 0, 1, and on the following days until complete epithelial healing occurred. Results showed the calf blood extract eye gel to be statistically more effective in promoting corneal wound healing, especially in patients with wound areas larger than 6 mm(2).

Effects of Problem-Solving Method on Secondary School Students' Achievement and Retention in Social Studies, in Ekiti State, Nigeria

ERIC Educational Resources Information Center

Abdu-Raheem, B. O.

2012-01-01

This study investigated the effects of problem-solving method of teaching on secondary school students' achievement and retention in Social Studies. The study adopted the quasi-experimental, pre-test, post-test, control group design. The sample for the study consisted of 240 Junior Secondary School Class II students randomly selected from six…

The association between the combined oral contraceptive pill and insulin resistance, dysglycemia and dyslipidemia in women with polycystic ovary syndrome: a systematic review and meta-analysis of observational studies.

PubMed

Halperin, Ilana J; Kumar, Shoba Sujana; Stroup, Donna F; Laredo, Sheila E

2011-01-01

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of young women. First-line treatment is often the oral contraceptive pill (OC), but evidence suggests that OC may worsen metabolic outcomes in this population. We undertook this meta-analysis of observational studies and cohorts from within randomized controlled studies to investigate the association between OC use and dysglycemia, dyslipidemia and insulin resistance (IR) in women with PCOS. We searched MEDLINE (1966-April 2010), EMBASE (1980-April 2010) and All EBM Reviews. We included prospective cohorts and RCTs that treated women, aged 13-44, with PCOS with OC for at least 3 months. Blinded quality assessment and data extraction were conducted on 35 included studies by two independent reviewers. We used random effects methods to calculate weighted mean differences as the effect size. We investigated heterogeneity using sequential removal of studies, subgroup analysis and meta-regression. OC use was significantly associated with an increase in high-density lipoprotein cholesterol (HDL-C) (P = 0.004) and triglycerides (P = 0.004). Significant heterogeneity was found in glucose, cholesterol, HDL-C, low-density lipoprotein cholesterol triglycerides, fasting glucose to insulin ratios and homeostatic model assessments-IR. Study characteristics such as mean BMI, mean age and duration of study could explain some of the heterogeneity. Use of OC was not associated with clinically significant adverse metabolic consequences. Because of limitations of the underlying studies, further research including rigorously designed randomized trials would more definitively confirm our findings.

Randomization in clinical trials in orthodontics: its significance in research design and methods to achieve it.

PubMed

Pandis, Nikolaos; Polychronopoulou, Argy; Eliades, Theodore

2011-12-01

Randomization is a key step in reducing selection bias during the treatment allocation phase in randomized clinical trials. The process of randomization follows specific steps, which include generation of the randomization list, allocation concealment, and implementation of randomization. The phenomenon in the dental and orthodontic literature of characterizing treatment allocation as random is frequent; however, often the randomization procedures followed are not appropriate. Randomization methods assign, at random, treatment to the trial arms without foreknowledge of allocation by either the participants or the investigators thus reducing selection bias. Randomization entails generation of random allocation, allocation concealment, and the actual methodology of implementing treatment allocation randomly and unpredictably. Most popular randomization methods include some form of restricted and/or stratified randomization. This article introduces the reasons, which make randomization an integral part of solid clinical trial methodology, and presents the main randomization schemes applicable to clinical trials in orthodontics.

Studies in astronomical time series analysis. I - Modeling random processes in the time domain

NASA Technical Reports Server (NTRS)

Scargle, J. D.

1981-01-01

Several random process models in the time domain are defined and discussed. Attention is given to the moving average model, the autoregressive model, and relationships between and combinations of these models. Consideration is then given to methods for investigating pulse structure, procedures of model construction, computational methods, and numerical experiments. A FORTRAN algorithm of time series analysis has been developed which is relatively stable numerically. Results of test cases are given to study the effect of adding noise and of different distributions for the pulse amplitudes. A preliminary analysis of the light curve of the quasar 3C 272 is considered as an example.

Processing speed and working memory training in multiple sclerosis: a double-blind randomized controlled pilot study.

PubMed

Hancock, Laura M; Bruce, Jared M; Bruce, Amanda S; Lynch, Sharon G

2015-01-01

Between 40-65% of multiple sclerosis patients experience cognitive deficits, with processing speed and working memory most commonly affected. This pilot study investigated the effect of computerized cognitive training focused on improving processing speed and working memory. Participants were randomized into either an active or a sham training group and engaged in six weeks of training. The active training group improved on a measure of processing speed and attention following cognitive training, and data trended toward significance on measures of other domains. Results provide preliminary evidence that cognitive training with multiple sclerosis patients may produce moderate improvement in select areas of cognitive functioning.

Effects of plasma nitric oxide levels on platelet activation in single donor apheresis and random donor concentrates.

PubMed

Büyükkağnici, Demet Iren; Ilhan, Osman; Kavas, Güzin Ozelçi; Arslan, Onder; Arat, Mutlu; Dalva, Klara; Ayyildiz, Erol

2007-02-01

P-selectin is an useful marker to determine platelet activation and nitric oxide inhibits platelet activation, secretion, adhesion and aggregation. The aim of this study was to investigate the relationship between nitric oxide and P-selectin values in both single donor apheresis and random donor platelet concentrates. According to the results of this study, we found that the best platelet concentrate is freshly prepared single donor apheresis concentrate and it is important to prevent activation at the beginning of the donation. Nitric oxide, which is synthesized from platelets during the storage period, is not sufficient to prevent platelet activation.

Measuring the effects of heterogeneity on distributed systems

NASA Technical Reports Server (NTRS)

El-Toweissy, Mohamed; Zeineldine, Osman; Mukkamala, Ravi

1991-01-01

Distributed computer systems in daily use are becoming more and more heterogeneous. Currently, much of the design and analysis studies of such systems assume homogeneity. This assumption of homogeneity has been mainly driven by the resulting simplicity in modeling and analysis. A simulation study is presented which investigated the effects of heterogeneity on scheduling algorithms for hard real time distributed systems. In contrast to previous results which indicate that random scheduling may be as good as a more complex scheduler, this algorithm is shown to be consistently better than a random scheduler. This conclusion is more prevalent at high workloads as well as at high levels of heterogeneity.

Photons in dense nuclear matter: Random-phase approximation

NASA Astrophysics Data System (ADS)

Stetina, Stephan; Rrapaj, Ermal; Reddy, Sanjay

2018-04-01

We present a comprehensive and pedagogic discussion of the properties of photons in cold and dense nuclear matter based on the resummed one-loop photon self-energy. Correlations among electrons, muons, protons, and neutrons in β equilibrium that arise as a result of electromagnetic and strong interactions are consistently taken into account within the random phase approximation. Screening effects, damping, and collective excitations are systematically studied in a fully relativistic setup. Our study is relevant to the linear response theory of dense nuclear matter, calculations of transport properties of cold dense matter, and investigations of the production and propagation of hypothetical vector bosons such as the dark photons.

Muscular and functional effects of partitioning exercising muscle mass in patients with chronic obstructive pulmonary disease - a study protocol for a randomized controlled trial.

PubMed

Nyberg, Andrè; Saey, Didier; Martin, Mickaël; Maltais, François

2015-04-27

Low-load, high-repetitive single-limb resistance training may increase limb muscle function and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD) while minimizing the occurrence of limiting exertional symptoms. Whether high-repetitive single-limb resistance training would perform better than high-repetitive two-limb resistance training is unknown. In addition, the mechanisms underlying possible benefits of high-repetitive resistance training has not been investigated. The aims of this study are to compare single versus two-limb high-repetitive resistance training in patients with COPD and to investigate mechanisms of action of these training modalities. This trial is a prospective, assessor-blind, randomized controlled trial. The participants are patients with stable severe to very severe COPD who are older than 40 years of age and healthy controls. The intervention is single-limb, high-repetitive, resistance training with elastic bands, three times/week for 8 weeks. The control is two-limb high-repetitive resistance training with elastic bands, three times/week for 8 weeks. The primary outcomes is change in the 6-min walking distance after 8 weeks of single-limb or two-limb high-repetitive resistance training. The secondary outcomes are changes in limb muscle strength and endurance capacity, key protein involved in quadriceps anabolic/catabolic signalization, fiber-type distribution and capillarization, subjective dyspnea and muscle fatigue, muscle oxygenation, cardiorespiratory demand and health-related quality-of-life after 8 weeks of single-limb or two-limb high-repetitive resistance training. The acute effects of single-limb versus two-limb high-repetitive resistance training on contractile fatigue, exercise stimulus (the product of number of repetition and load), subjective dyspnea and muscle fatigue, muscle oxygenation, and cardiorespiratory demand during upper and lower limb exercises will also be investigated in patients with COPD and healthy controls. Randomization will be performed using a random number generator by a person independent of the recruitment process, using 1:1 allocation to the intervention and the control group using random block sizes. All outcome assessors will be blinded to group assignment. The results of this project will provide important information to help developing and implementing customized exercise training programs for patients with COPD. ClinicalTrials.gov Identifier NCT02283580 Registration date: 4 November 2014. First participant randomized: 10 November 2014.

Robotic Surgery Readiness (RSR): A Prospective Randomized Skills Decay Recognition and Prevention Study

DTIC Science & Technology

2017-08-01

Evaluative Assessment of Robotic Skills (GEARS) scoring will be correlated by the Principal Investigator (Dr. Thomas Lendvay - UW) and Co-Investigator (Dr...be evaluated and developed through collaboration with the Intuitive Surgical Consultant (Simon DiMaio, Senior Research Manager). We will deliver...Virtual Reality Simulation Curriculum GEARS - Global Evaluative Assessment of Robotic Skills Surgical Education 6 of 41 3. ACCOMPLISHMENTS: What

Can We Make Definite Categorization of Student Attitudes? A Rough Set Approach to Investigate Students' Implicit Attitudinal Typologies toward Living Things

ERIC Educational Resources Information Center

Narli, Serkan; Yorek, Nurettin; Sahin, Mehmet; Usak, Muhammet

2010-01-01

This study investigates the possibility of analyzing educational data using the theory of rough sets which is mostly employed in the fields of data analysis and data mining. Data were collected using an open-ended conceptual understanding test of the living things administered to first-year high school students. The responses of randomly selected…

Regression Artifacts in Nonequivalent Control Group Designs: An Empirical Investigation of Bias in ANCOVA and Matching Designs.

ERIC Educational Resources Information Center

Vermillion, James E.

The presence of artifactual bias in analysis of covariance (ANCOVA) and in matching nonequivalent control group (NECG) designs was empirically investigated. The data set was obtained from a study of the effects of a television program on children from three day care centers in Mexico in which the subjects had been randomly selected within centers.…

Gender Pay Equity in Higher Education: Salary Differentials and Predictors of Base Faculty Income

ERIC Educational Resources Information Center

Meyers, Laura E.

2011-01-01

This study investigates faculty gender pay equity in higher education. Using data from the 2004 National Study of Postsecondary Faculty and drawing on human capital theory, structural theory, and the theory of comparable worth, this study uses cross-classified random effects modeling to explore what factors may be contributing to the pay…

Learning English through Actions: A Study of Mobile-Assisted Language Learning

ERIC Educational Resources Information Center

Liu, Pei-Lin; Chen, Chiu-Jung

2015-01-01

This study investigated the impact of taking photos using mobile phones on the English phrase-learning performance of English as a second-language learners. A total of 116 students enrolled in a college in Central Taiwan participated in this study. The participants were divided randomly into two groups: a control group and an experimental group…

Identifying and Overcoming Barriers to Diabetes Management in the Elderly: An Intervention Study

DTIC Science & Technology

2008-06-01

11 4 Introduction: Subject: Research regarding older adults and, in particular, those with diabetes, lags far...research: In this study, patients over age 70 with diabetes will be randomized to care by either geriatric diabetes intervention team (GDT) or attention...Diabetes Management in the Elderly : An Intervention Study PRINCIPAL INVESTIGATOR: Medha Munshi CONTRACTING

Visual Literacy and the Integration of Parametric Modeling in the Problem-Based Curriculum

ERIC Educational Resources Information Center

Assenmacher, Matthew Benedict

2013-01-01

This quasi-experimental study investigated the application of visual literacy skills in the form of parametric modeling software in relation to traditional forms of sketching. The study included two groups of high school technical design students. The control and experimental groups involved in the study consisted of two randomly selected groups…

Perceived Indices of Truancy among Selected Adolescents in Oyo Town: Implications for Behavioural Change

ERIC Educational Resources Information Center

Adika, Lawrence Olagoke

2016-01-01

The study investigated perceived indices of truancy behaviour among selected adolescents in Oyo town. The descriptive survey study had 200 randomly selected adolescents from five secondary schools in Oyo town. A self-designed instrument tagged Adolescent Truancy Scale (ATS) was employed in collecting data for the study and the data was subjected…

English as Second Language: Students' Awareness of Learning Strategies Used in Reading Comprehension

ERIC Educational Resources Information Center

Hussain, Irshad; Javed, Muhammad; Munshi, Parveen

2015-01-01

This study investigated the reading strategies used by adult learners' to read materials in English language for their studies. The population of the study consisted of students of Universiti Sains Malaysia. A sample of 80 (40 Postgraduates and 40 Undergraduates) TESOL students enrolled in the University were selected randomly. The data were…

A Study of the Relationships between Distributed Leadership, Teacher Academic Optimism and Student Achievement in Taiwanese Elementary Schools

ERIC Educational Resources Information Center

Chang, I-Hua

2011-01-01

The purpose of this study was to explore the relationships between distributed leadership, teachers' academic optimism and student achievement in learning. The study targeted public elementary schools in Taiwan and adopted stratified random sampling to investigate 1500 teachers. Teachers' perceptions were collected by a self-report scale. In…

Scaling behavior for random walks with memory of the largest distance from the origin

NASA Astrophysics Data System (ADS)

Serva, Maurizio

2013-11-01

We study a one-dimensional random walk with memory. The behavior of the walker is modified with respect to the simple symmetric random walk only when he or she is at the maximum distance ever reached from his or her starting point (home). In this case, having the choice to move farther or to move closer, the walker decides with different probabilities. If the probability of a forward step is higher then the probability of a backward step, the walker is bold, otherwise he or she is timorous. We investigate the asymptotic properties of this bold-timorous random walk, showing that the scaling behavior varies continuously from subdiffusive (timorous) to superdiffusive (bold). The scaling exponents are fully determined with a new mathematical approach based on a decomposition of the dynamics in active journeys (the walker is at the maximum distance) and lazy journeys (the walker is not at the maximum distance).

Effect of Phase-Breaking Events on Electron Transport in Mesoscopic and Nanodevices

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

Meunier, Vincent; Mintmire, John W; Thushari, Jayasekera

2008-01-01

Existing ballistic models for electron transport in mesoscopic and nanoscale systems break down as the size of the device becomes longer than the phase coherence length of electrons in the system. Krstic et al. experimentally observed that the current in single-wall carbon nanotube systems can be regarded as a combination of a coherent part and a noncoherent part. In this article, we discuss the use of Buettiker phase-breaking technique to address partially coherent electron transport, generalize that to a multichannel problem, and then study the effect of phase-breaking events on the electron transport in two-terminal graphene nanoribbon devices. We alsomore » investigate the difference between the pure-phase randomization and phase/momentum randomization boundary conditions. While momentum randomization adds an extra resistance caused by backward scattering, pure-phase randomization smooths the conductance oscillations because of interference.« less

The risk-stratified osteoporosis strategy evaluation study (ROSE): a randomized prospective population-based study. Design and baseline characteristics.

PubMed

Rubin, Katrine Hass; Holmberg, Teresa; Rothmann, Mette Juel; Høiberg, Mikkel; Barkmann, Reinhard; Gram, Jeppe; Hermann, Anne Pernille; Bech, Mickael; Rasmussen, Ole; Glüer, Claus C; Brixen, Kim

2015-02-01

The risk-stratified osteoporosis strategy evaluation study (ROSE) is a randomized prospective population-based study investigating the effectiveness of a two-step screening program for osteoporosis in women. This paper reports the study design and baseline characteristics of the study population. 35,000 women aged 65-80 years were selected at random from the population in the Region of Southern Denmark and-before inclusion-randomized to either a screening group or a control group. As first step, a self-administered questionnaire regarding risk factors for osteoporosis based on FRAX(®) was issued to both groups. As second step, subjects in the screening group with a 10-year probability of major osteoporotic fractures ≥15% were offered a DXA scan. Patients diagnosed with osteoporosis from the DXA scan were advised to see their GP and discuss pharmaceutical treatment according to Danish National guidelines. The primary outcome is incident clinical fractures as evaluated through annual follow-up using the Danish National Patient Registry. The secondary outcomes are cost-effectiveness, participation rate, and patient preferences. 20,904 (60%) women participated and included in the baseline analyses (10,411 in screening and 10,949 in control group). The mean age was 71 years. As expected by randomization, the screening and control groups had similar baseline characteristics. Screening for osteoporosis is at present not evidence based according to the WHO screening criteria. The ROSE study is expected to provide knowledge of the effectiveness of a screening strategy that may be implemented in health care systems to prevent fractures.

Pelvic floor muscle training for bowel dysfunction following colorectal cancer surgery: A systematic review.

PubMed

Lin, Kuan-Yin; Granger, Catherine L; Denehy, Linda; Frawley, Helena C

2015-11-01

To identify, evaluate and synthesize the evidence examining the effectiveness of pelvic floor muscle training (PFMT) on bowel dysfunction in patients who have undergone colorectal cancer surgery. Eight electronic databases (MEDLINE 1950-2014; CINAHL 1982-2014; EMBASE 1980-2014; Scopus 1823-2014; PsycINFO 1806-2014; Web of Science 1970-2014; Cochrane Library 2014; PEDro 1999-2014) were systematically searched in March 2014. Reference lists of identified articles were cross referenced and hand searched. Randomized controlled trials, cohort studies and case series were included if they investigated the effects of conservative treatments, including PFMT on bowel function in patients with colorectal cancer following surgery. Two reviewers independently assessed the risk of bias of studies using the Newcastle-Ottawa Scale (NOS). Six prospective non-randomized studies and two retrospective studies were included. The mean (SD) NOS risk of bias score was 4.9 (1.2) out of 9; studies were limited by a lack of non-exposed cohort, lack of independent blinded assessment, heterogeneous treatment protocols, and lack of long-term follow-up. The majority of studies reported significant improvements in stool frequency, incontinence episodes, severity of fecal incontinence, and health-related quality of life (HRQoL) after PFMT. Meta-analysis was not possible due to lack of randomized controlled trials. Pelvic floor muscle training for patients following surgery for colorectal cancer appears to be associated with improvements in bowel function and HRQoL. Results from non-randomized studies are promising but randomized controlled trials with sufficient power are needed to confirm the effectiveness of PFMT in this population. © 2014 Wiley Periodicals, Inc.

Analgesic effects of treatments for non-specific low back pain: a meta-analysis of placebo-controlled randomized trials.

PubMed

Machado, L A C; Kamper, S J; Herbert, R D; Maher, C G; McAuley, J H

2009-05-01

Estimates of treatment effects reported in placebo-controlled randomized trials are less subject to bias than those estimates provided by other study designs. The objective of this meta-analysis was to estimate the analgesic effects of treatments for non-specific low back pain reported in placebo-controlled randomized trials. Medline, Embase, Cinahl, PsychInfo and Cochrane Central Register of Controlled Trials databases were searched for eligible trials from earliest records to November 2006. Continuous pain outcomes were converted to a common 0-100 scale and pooled using a random effects model. A total of 76 trials reporting on 34 treatments were included. Fifty percent of the investigated treatments had statistically significant effects, but for most the effects were small or moderate: 47% had point estimates of effects of <10 points on the 100-point scale, 38% had point estimates from 10 to 20 points and 15% had point estimates of >20 points. Treatments reported to have large effects (>20 points) had been investigated only in a single trial. This meta-analysis revealed that the analgesic effects of many treatments for non-specific low back pain are small and that they do not differ in populations with acute or chronic symptoms.

Bone mineral density and risk of type 2 diabetes and coronary heart disease: A Mendelian randomization study.

PubMed

Gan, Wei; Clarke, Robert J; Mahajan, Anubha; Kulohoma, Benard; Kitajima, Hidetoshi; Robertson, Neil R; Rayner, N William; Walters, Robin G; Holmes, Michael V; Chen, Zhengming; McCarthy, Mark I

2017-01-01

Background: Observational studies have demonstrated that increased bone mineral density is associated with a higher risk of type 2 diabetes (T2D), but the relationship with risk of coronary heart disease (CHD) is less clear. Moreover, substantial uncertainty remains about the causal relevance of increased bone mineral density for T2D and CHD, which can be assessed by Mendelian randomisation studies.  Methods: We identified 235 independent single nucleotide polymorphisms (SNPs) associated at p <5×10 -8 with estimated heel bone mineral density (eBMD) in 116,501 individuals from the UK Biobank study, accounting for 13.9% of eBMD variance. For each eBMD-associated SNP, we extracted effect estimates from the largest available GWAS studies for T2D (DIAGRAM: n=26,676 T2D cases and 132,532 controls) and CHD (CARDIoGRAMplusC4D: n=60,801 CHD cases and 123,504 controls). A two-sample design using several Mendelian randomization approaches was used to investigate the causal relevance of eBMD for risk of T2D and CHD. In addition, we explored the relationship of eBMD, instrumented by the 235 SNPs, on 12 cardiovascular and metabolic risk factors. Finally, we conducted Mendelian randomization analysis in the reverse direction to investigate reverse causality. Results: Each one standard deviation increase in genetically instrumented eBMD (equivalent to 0.14 g/cm 2 ) was associated with an 8% higher risk of T2D (odds ratio [OR] 1.08; 95% confidence interval [CI]: 1.02 to 1.14; p =0.012) and 5% higher risk of CHD (OR 1.05; 95%CI: 1.00 to 1.10; p =0.034). Consistent results were obtained in sensitivity analyses using several different Mendelian randomization approaches. Equivalent increases in eBMD were also associated with lower plasma levels of HDL-cholesterol and increased insulin resistance. Mendelian randomization in the reverse direction using 94 T2D SNPs or 52 CHD SNPs showed no evidence of reverse causality with eBMD. Conclusions: These findings suggest a causal relationship between elevated bone mineral density with risks of both T2D and CHD.

The effects of computer-based mindfulness training on Self-control and Mindfulness within Ambulatorily assessed network Systems across Health-related domains in a healthy student population (SMASH): study protocol for a randomized controlled trial.

PubMed

Rowland, Zarah; Wenzel, Mario; Kubiak, Thomas

2016-12-01

Self-control is an important ability in everyday life, showing associations with health-related outcomes. The aim of the Self-control and Mindfulness within Ambulatorily assessed network Systems across Health-related domains (SMASH) study is twofold: first, the effectiveness of a computer-based mindfulness training will be evaluated in a randomized controlled trial. Second, the SMASH study implements a novel network approach in order to investigate complex temporal interdependencies of self-control networks across several domains. The SMASH study is a two-armed, 6-week, non-blinded randomized controlled trial that combines seven weekly laboratory meetings and 40 days of electronic diary assessments with six prompts per day in a healthy undergraduate student population at the Johannes Gutenberg University Mainz, Germany. Participants will be randomly assigned to (1) receive a computer-based mindfulness intervention or (2) to a wait-list control condition. Primary outcomes are self-reported momentary mindfulness and self-control assessed via electronic diaries. Secondary outcomes are habitual mindfulness and habitual self-control. Further measures include self-reported behaviors in specific self-control domains: emotion regulation, alcohol consumption and eating behaviors. The effects of mindfulness training on primary and secondary outcomes are explored using three-level mixed models. Furthermore, networks will be computed with vector autoregressive mixed models to investigate the dynamics at participant and group level. This study was approved by the local ethics committee (reference code 2015_JGU_psychEK_011) and follows the standards laid down in the Declaration of Helsinki (2013). This randomized controlled trial combines an intensive Ambulatory Assessment of 40 consecutive days and seven laboratory meetings. By implementing a novel network approach, underlying processes of self-control within different health domains will be identified. These results will deepen the understanding of self-control performance and will guide to just-in-time individual interventions for several health-related behaviors. ClinicalTrials.gov, NCT02647801 . Registered on 15 December 2015 (registered retrospectively). .

Some practical problems in implementing randomization.

PubMed

Downs, Matt; Tucker, Kathryn; Christ-Schmidt, Heidi; Wittes, Janet

2010-06-01

While often theoretically simple, implementing randomization to treatment in a masked, but confirmable, fashion can prove difficult in practice. At least three categories of problems occur in randomization: (1) bad judgment in the choice of method, (2) design and programming errors in implementing the method, and (3) human error during the conduct of the trial. This article focuses on these latter two types of errors, dealing operationally with what can go wrong after trial designers have selected the allocation method. We offer several case studies and corresponding recommendations for lessening the frequency of problems in allocating treatment or for mitigating the consequences of errors. Recommendations include: (1) reviewing the randomization schedule before starting a trial, (2) being especially cautious of systems that use on-demand random number generators, (3) drafting unambiguous randomization specifications, (4) performing thorough testing before entering a randomization system into production, (5) maintaining a dataset that captures the values investigators used to randomize participants, thereby allowing the process of treatment allocation to be reproduced and verified, (6) resisting the urge to correct errors that occur in individual treatment assignments, (7) preventing inadvertent unmasking to treatment assignments in kit allocations, and (8) checking a sample of study drug kits to allow detection of errors in drug packaging and labeling. Although we performed a literature search of documented randomization errors, the examples that we provide and the resultant recommendations are based largely on our own experience in industry-sponsored clinical trials. We do not know how representative our experience is or how common errors of the type we have seen occur. Our experience underscores the importance of verifying the integrity of the treatment allocation process before and during a trial. Clinical Trials 2010; 7: 235-245. http://ctj.sagepub.com.

Investigating the Relationship between Self-Handicapping Tendencies, Self-Esteem and Cognitive Distortions

ERIC Educational Resources Information Center

Yavuzer, Yasemin

2015-01-01

The purpose of this study is to examine the relationship between cognitive distortions, self-handicapping tendencies, and self-esteem in a sample of students studying in a school of education. The sample of the study was comprised of 507 volunteer students chosen through random sampling from a total of 4,720 students who were studying teaching at…

Selective Attentional Effects of Adjunct Study Questions on Achievement in Nigerian Secondary School Science

ERIC Educational Resources Information Center

Okoye, Nnamdi S.

2008-01-01

The study investigated the selective attentional effects of adjunct study questions inserted before or after the presentation of science flow diagrams. The basic design for the study was a post-test only control group design involving a total of 252 students randomly selected from six secondary schools in Ile-Ife, Oshun State Nigeria. These were…

An Empirical Study about China: Gender Equity in Science Education.

ERIC Educational Resources Information Center

Wang, Jianjun; Staver, John R.

A data base representing a random sample of more than 10,000 grade 9 students in an SISS (Second IEA Science Study) Extended Study (SES), a key project supported by the China State Commission of Education in the late 1980s, was employed in this study to investigate gender equity in student science achievement in China. This empirical data analysis…

Importance of methodology on (99m)technetium dimercapto-succinic acid scintigraphic image quality: imaging pilot study for RIVUR (Randomized Intervention for Children With Vesicoureteral Reflux) multicenter investigation.

PubMed

Ziessman, Harvey A; Majd, Massoud

2009-07-01

We reviewed our experience with (99m)technetium dimercapto-succinic acid scintigraphy obtained during an imaging pilot study for a multicenter investigation (Randomized Intervention for Children With Vesicoureteral Reflux) of the effectiveness of daily antimicrobial prophylaxis for preventing recurrent urinary tract infection and renal scarring. We analyzed imaging methodology and its relation to diagnostic image quality. (99m)Technetium dimercapto-succinic acid imaging guidelines were provided to participating sites. High-resolution planar imaging with parallel hole or pinhole collimation was required. Two core reviewers evaluated all submitted images. Analysis included appropriate views, presence or lack of patient motion, adequate magnification, sufficient counts and diagnostic image quality. Inter-reader agreement was evaluated. We evaluated 70, (99m)technetium dimercapto-succinic acid studies from 14 institutions. Variability was noted in methodology and image quality. Correlation (r value) between dose administered and patient age was 0.780. For parallel hole collimator imaging good correlation was noted between activity administered and counts (r = 0.800). For pinhole imaging the correlation was poor (r = 0.110). A total of 10 studies (17%) were rejected for quality issues of motion, kidney overlap, inadequate magnification, inadequate counts and poor quality images. The submitting institution was informed and provided with recommendations for improving quality, and resubmission of another study was required. Only 4 studies (6%) were judged differently by the 2 reviewers, and the differences were minor. Methodology and image quality for (99m)technetium dimercapto-succinic acid scintigraphy varied more than expected between institutions. The most common reason for poor image quality was inadequate count acquisition with insufficient attention to the tradeoff between administered dose, length of image acquisition, start time of imaging and resulting image quality. Inter-observer core reader agreement was high. The pilot study ensured good diagnostic quality standardized images for the Randomized Intervention for Children With Vesicoureteral Reflux investigation.

Fast Magnetic Micropropellers with Random Shapes

PubMed Central

2015-01-01

Studying propulsion mechanisms in low Reynolds number fluid has implications for many fields, ranging from the biology of motile microorganisms and the physics of active matter to micromixing in catalysis and micro- and nanorobotics. The propulsion of magnetic micropropellers can be characterized by a dimensionless speed, which solely depends on the propeller geometry for a given axis of rotation. However, this dependence has so far been only investigated for helical propeller shapes, which were assumed to be optimal. In order to explore a larger variety of shapes, we experimentally studied the propulsion properties of randomly shaped magnetic micropropellers. Surprisingly, we found that their dimensionless speeds are high on average, comparable to previously reported nanofabricated helical micropropellers. The highest dimensionless speed we observed is higher than that of any previously reported propeller moving in a low Reynolds number fluid, proving that physical random shape generation can be a viable optimization strategy. PMID:26383225

Pushing the glass transition towards random close packing using self-propelled hard spheres

NASA Astrophysics Data System (ADS)

Ni, Ran; Stuart, Martien A. Cohen; Dijkstra, Marjolein

2013-10-01

Although the concept of random close packing with an almost universal packing fraction of approximately 0.64 for hard spheres was introduced more than half a century ago, there are still ongoing debates. The main difficulty in searching the densest packing is that states with packing fractions beyond the glass transition at approximately 0.58 are inherently non-equilibrium systems, where the dynamics slows down with a structural relaxation time diverging with density; hence, the random close packing is inaccessible. Here we perform simulations of self-propelled hard spheres, and we find that with increasing activity the relaxation dynamics can be sped up by orders of magnitude. The glass transition shifts to higher packing fractions upon increasing the activity, allowing the study of sphere packings with fluid-like dynamics at packing fractions close to RCP. Our study opens new possibilities of investigating dense packings and the glass transition in systems of hard particles.

Effect of Rosa damascene aromatherapy on sleep quality in cardiac patients: a randomized controlled trial.

PubMed

Hajibagheri, Ali; Babaii, Atye; Adib-Hajbaghery, Mohsen

2014-08-01

Sleep disorders are common among patients hospitalized in coronary care unit (CCU). This study aimed to investigate the effect of Rosa damascene aromatherapy on sleep quality of patients hospitalized in CCU. In this randomized controlled trial, 60 patients who met the inclusion criteria were conveniently sampled and randomly allocated to the experimental and control groups. Patients in the control group received routine care. In the experimental group, patients received routine care and Rosa damascene aromatherapy for three subsequent nights. In the both groups the sleep quality was assessed using the Pittsburgh Sleep Quality Index. After the study, the mean scores of five domains of Pittsburg Sleep Quality Index as well as the mean of total score of the index in the experimental group were significantly lower than the control group. Rosa damascene aromatherapy can significantly improve the sleep quality of patients hospitalized in CCUs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of dynamic noise affecting geodynamics information in a tethered subsatellite

NASA Technical Reports Server (NTRS)

Gullahorn, G. E.

1985-01-01

Work performed as part of an investigation of noise affecting instrumentation in a tethered subsatellite, was studied. The following specific topics were addressed during the reporting period: a method for stabilizing the subsatellite against the rotational effects of atmospheric perturbation was developed; a variety of analytic studies of tether dynamics aimed at elucidating dynamic noise processes were performed; a novel mechanism for coupling longitudinal and latitudinal oscillations of the tether was discovered, and random vibration analysis for modeling the tethered subsatellite under atmospheric perturbation were studied.

Generation Mechanism of Nonlinear Rayleigh Surface Waves for Randomly Distributed Surface Micro-Cracks.

PubMed

Ding, Xiangyan; Li, Feilong; Zhao, Youxuan; Xu, Yongmei; Hu, Ning; Cao, Peng; Deng, Mingxi

2018-04-23

This paper investigates the propagation of Rayleigh surface waves in structures with randomly distributed surface micro-cracks using numerical simulations. The results revealed a significant ultrasonic nonlinear effect caused by the surface micro-cracks, which is mainly represented by a second harmonic with even more distinct third/quadruple harmonics. Based on statistical analysis from the numerous results of random micro-crack models, it is clearly found that the acoustic nonlinear parameter increases linearly with micro-crack density, the proportion of surface cracks, the size of micro-crack zone, and the excitation frequency. This study theoretically reveals that nonlinear Rayleigh surface waves are feasible for use in quantitatively identifying the physical characteristics of surface micro-cracks in structures.

Effect of H-wave polarization on laser radar detection of partially convex targets in random media.

PubMed

El-Ocla, Hosam

2010-07-01

A study on the performance of laser radar cross section (LRCS) of conducting targets with large sizes is investigated numerically in free space and random media. The LRCS is calculated using a boundary value method with beam wave incidence and H-wave polarization. Considered are those elements that contribute to the LRCS problem including random medium strength, target configuration, and beam width. The effect of the creeping waves, stimulated by H-polarization, on the LRCS behavior is manifested. Targets taking large sizes of up to five wavelengths are sufficiently larger than the beam width and are sufficient for considering fairly complex targets. Scatterers are assumed to have analytical partially convex contours with inflection points.

Percolation of localized attack on complex networks

NASA Astrophysics Data System (ADS)

Shao, Shuai; Huang, Xuqing; Stanley, H. Eugene; Havlin, Shlomo

2015-02-01

The robustness of complex networks against node failure and malicious attack has been of interest for decades, while most of the research has focused on random attack or hub-targeted attack. In many real-world scenarios, however, attacks are neither random nor hub-targeted, but localized, where a group of neighboring nodes in a network are attacked and fail. In this paper we develop a percolation framework to analytically and numerically study the robustness of complex networks against such localized attack. In particular, we investigate this robustness in Erdős-Rényi networks, random-regular networks, and scale-free networks. Our results provide insight into how to better protect networks, enhance cybersecurity, and facilitate the design of more robust infrastructures.

Generation Mechanism of Nonlinear Rayleigh Surface Waves for Randomly Distributed Surface Micro-Cracks

PubMed Central

Ding, Xiangyan; Li, Feilong; Xu, Yongmei; Cao, Peng; Deng, Mingxi

2018-01-01

This paper investigates the propagation of Rayleigh surface waves in structures with randomly distributed surface micro-cracks using numerical simulations. The results revealed a significant ultrasonic nonlinear effect caused by the surface micro-cracks, which is mainly represented by a second harmonic with even more distinct third/quadruple harmonics. Based on statistical analysis from the numerous results of random micro-crack models, it is clearly found that the acoustic nonlinear parameter increases linearly with micro-crack density, the proportion of surface cracks, the size of micro-crack zone, and the excitation frequency. This study theoretically reveals that nonlinear Rayleigh surface waves are feasible for use in quantitatively identifying the physical characteristics of surface micro-cracks in structures. PMID:29690580

Toward negative Poisson's ratio composites: Investigation of the auxetic behavior of fibrous networks

NASA Astrophysics Data System (ADS)

Tatlier, Mehmet Seha

Random fibrous can be found among natural and synthetic materials. Some of these random fibrous networks possess negative Poisson's ratio and they are extensively called auxetic materials. The governing mechanisms behind this counter intuitive property in random networks are yet to be understood and this kind of auxetic material remains widely under-explored. However, most of synthetic auxetic materials suffer from their low strength. This shortcoming can be rectified by developing high strength auxetic composites. The process of embedding auxetic random fibrous networks in a polymer matrix is an attractive alternate route to the manufacture of auxetic composites, however before such an approach can be developed, a methodology for designing fibrous networks with the desired negative Poisson's ratios must first be established. This requires an understanding of the factors which bring about negative Poisson's ratios in these materials. In this study, a numerical model is presented in order to investigate the auxetic behavior in compressed random fiber networks. Finite element analyses of three-dimensional stochastic fiber networks were performed to gain insight into the effects of parameters such as network anisotropy, network density, and degree of network compression on the out-of-plane Poisson's ratio and Young's modulus. The simulation results suggest that the compression is the critical parameter that gives rise to negative Poisson's ratio while anisotropy significantly promotes the auxetic behavior. This model can be utilized to design fibrous auxetic materials and to evaluate feasibility of developing auxetic composites by using auxetic fibrous networks as the reinforcing layer.

Intention-to-treat analysis and accounting for missing data in orthopaedic randomized clinical trials.

PubMed

Herman, Amir; Botser, Itamar Busheri; Tenenbaum, Shay; Chechick, Ahron

2009-09-01

The intention-to-treat principle implies that all patients who are randomized in a clinical trial should be analyzed according to their original allocation. This means that patients crossing over to another treatment group and patients lost to follow-up should be included in the analysis as a part of their original group. This principle is important for preserving the randomization scheme, which is the basis for correct inference in any randomized trial. In this study, we examined the use of the intention-to-treat principle in recently published orthopaedic clinical trials. We surveyed eight leading orthopaedic journals for randomized clinical trials published between January 2005 and August 2008. We determined whether the intention-to-treat principle was implemented and, if so, how it was used in each trial. Specifically, we ascertained which methods were used to account for missing data. Our search yielded 274 randomized clinical trials, and the intention-to-treat principle was used in ninety-six (35%) of them. There were significant differences among the journals with regard to the use of the intention-to-treat principle. The relative number of trials in which the principle was used increased each year. The authors adhered to the strict definition of the intention-to-treat principle in forty-five of the ninety-six studies in which it was claimed that this principle had been used. In forty-four randomized trials, patients who had been lost to follow-up were excluded from the final analysis; this practice was most notable in studies of surgical interventions. The most popular method of adjusting for missing data was the "last observation carried forward" technique. In most of the randomized clinical trials published in the orthopaedic literature, the investigators did not adhere to the stringent use of the intention-to-treat principle, with the most conspicuous problem being a lack of accounting for patients lost to follow-up. This omission might introduce bias to orthopaedic randomized clinical trials and their analysis.

An analysis of the effect of funding source in randomized clinical trials of second generation antipsychotics for the treatment of schizophrenia.

PubMed

Montgomery, John H; Byerly, Matthew; Carmody, Thomas; Li, Baitao; Miller, Daniel R; Varghese, Femina; Holland, Rhiannon

2004-12-01

The effect of funding source on the outcome of randomized controlled trials has been investigated in several medical disciplines; however, psychiatry has been largely excluded from such analyses. In this article, randomized controlled trials of second generation antipsychotics in schizophrenia are reviewed and analyzed with respect to funding source (industry vs. non-industry funding). A literature search was conducted for randomized, double-blind trials in which at least one of the tested treatments was a second generation antipsychotic. In each study, design quality and study outcome were assessed quantitatively according to rating scales. Mean quality and outcome scores were compared in the industry-funded studies and non-industry-funded studies. An analysis of the primary author's affiliation with industry was similarly performed. Results of industry-funded studies significantly favored second generation over first generation antipsychotics when compared to non-industry-funded studies. Non-industry-funded studies showed a trend toward higher quality than industry-funded studies; however, the difference between the two was not significant. Also, within the industry-funded studies, outcomes of trials involving first authors employed by industry sponsors demonstrated a trend toward second generation over first generation antipsychotics to a greater degree than did trials involving first authors employed outside the industry (p=0.05). While the retrospective design of the study limits the strength of the findings, the data suggest that industry bias may occur in randomized controlled trials in schizophrenia. There appears to be several sources by which bias may enter clinical research, including trial design, control of data analysis and multiplicity/redundancy of trials.

Practicing Field Hockey Skills Along the Contextual Interference Continuum: A Comparison of Five Practice Schedules

PubMed Central

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J. Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners. PMID:24149204

Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

PubMed

Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

2012-01-01

To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

Impact of Thematic Approach on Communication Skill in Preschool

ERIC Educational Resources Information Center

Ashokan, Varun; Venugopal, Kalpana

2016-01-01

The study investigated the effects of thematic approach on communication skills for preschool children. The study was a quasi experimental non-equivalent pretest-post-test control group design whereby 5-6 year old preschool children (n = 49) were randomly assigned to an experimental and a control group. The experimental group students were exposed…

The Impact of Video-Based Materials on Chinese-Speaking Learners' English Text Comprehension

ERIC Educational Resources Information Center

Lin, Lu-Fang

2016-01-01

This study investigated whether video-based materials can facilitate second language learners' text comprehension at the levels of macrostructure and microstructure. Three classes inclusive of 98 Chinese-speaking university students joined this study. The three classes were randomly assigned to three treatment groups: on-screen text (T Group),…

Teacher-Implemented Joint Attention Intervention: Pilot Randomized Controlled Study for Preschoolers with Autism

ERIC Educational Resources Information Center

Lawton, Kathy; Kasari, Connie

2012-01-01

Objective: The vast majority of children with an autism spectrum disorder (ASD) attend public preschools at some point in their childhood. Community preschool practices often are not evidence based, and almost none target the prelinguistic core deficits of ASD. This study investigated the effectiveness of public preschool teachers implementing a…

Science Teachers' Information Processing Behaviours in Nepal: A Reflective Comparative Study

ERIC Educational Resources Information Center

Acharya, Kamal Prasad

2017-01-01

This study examines the investigation of the information processing behaviours of secondary level science teachers. It is based on the data collected from 50 secondary level school science teachers working in Kathmandy valley. The simple random sampling and the Cognitive Style Inventory have been used respectively as the technique and tool to…

Parent-Infant Vocalisations at 12 Months Predict Psychopathology at 7 Years

ERIC Educational Resources Information Center

Allely, C. S.; Purves, D.; McConnachie, A.; Marwick, H.; Johnson, P.; Doolin, O.; Puckering, C.; Golding, J.; Gillberg, C.; Wilson, P.

2013-01-01

This study investigated the utility of adult and infant vocalisation in the prediction of child psychopathology. Families were sampled from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Vocalisation patterns were obtained from 180 videos (60 cases and 120 randomly selected sex-matched controls) of parent-infant…

Literacy, Information and Communication Technology as Tools for Empowerment of Inmates

ERIC Educational Resources Information Center

Joseph, Tenibiaje Dele

2012-01-01

The study investigated the present position of literacy, information and communication technology (ICT) in prisons by examining the perception of inmates. The study adopted a descriptive survey using structured questionnaire and observation guides on a randomly and purposively drawn sample of 664 inmates out of a population of 47,628 inmates…

Investigation of Relationship between Aggression and Sociometric Popularity in Adolescents

ERIC Educational Resources Information Center

Yavuzer, Yasemin

2013-01-01

In this study, it was aimed to determine the linear and curvilinear relationships between adolescent aggression and sociometric popularity. 524 adolescents randomly selected from 20 elementary schools in Nigde city center formed the study group. The participants were from 8th grade in 20 different classrooms. The research data were collected by…

Supplemental dietary L-arginine attenuates intestinal mucosal disruption during a coccidial vaccine challenge in broiler chickens

USDA-ARS?s Scientific Manuscript database

The present study investigated the effects of dietary arginine (Arg) supplementation on intestinal barrier integrity in broiler chickens undergoing coccidial challenge. The design of this study was a randomized complete block employing a 3 x 2 factorial arrangement (n = 8) with 3 level of Arg (1.11,...

Correlates of Examination Malpractice among Secondary School Students in Oyo State, Nigeria

ERIC Educational Resources Information Center

Animasahun, R. A.; Ogunniran, J. O.

2014-01-01

The purpose of this study is to investigate the correlates of examination malpractice among secondary school students in Oyo State, Nigeria. The instrument used for the study was tagged Predisposing Factors towards Examination Malpractice Questionnaire (PFTEMQ). The instrument was administered to 300 students randomly selected from 20 multi staged…

Factors Influencing Mathematic Problem-Solving Ability of Sixth Grade Students

ERIC Educational Resources Information Center

Pimta, Sakorn; Tayraukham, Sombat; Nuangchalerm, Prasart

2009-01-01

Problem statement: This study aims to investigate factors influencing mathematic problem-solving ability of sixth grade students. One thousand and twenty eight of sixth grade students, studying in the second semester of academic year 2007 were sampled by stratified random sampling technique. Approach: The research instruments used in the study…

Mobile Seamless Technology Enhanced CSL Oral Communication

ERIC Educational Resources Information Center

Lan, Yu-Ju; Lin, Yen-Ting

2016-01-01

The current study aimed at investigating how mobile seamless technology can be used to enhance the pragmatic competence of learners of Chinese as a second language (CSL). 34 overseas CSL learners participated in this study. They were randomly assigned into two groups: the classroom group, executing language tasks in fake contexts in a traditional…

Perceptions of Online Credentials for School Principals

ERIC Educational Resources Information Center

Richardson, Jayson W.; McLeod, Scott; Dikkers, Amy Garrett

2011-01-01

Purpose: The purpose of this study is to investigate the perceptions of human resource directors in the USA about online credentials earned by K-12 school principals and principal candidates. Design/methodology/approach: In this mixed methods study, a survey was sent to a random sample of 500 human resource directors in K-12 school districts…

Supplementing Literacy Instruction with a Media-Rich Intervention: Results of a Randomized Controlled Trial

ERIC Educational Resources Information Center

Penuel, William R.; Bates, Lauren; Gallagher, Lawrence P.; Pasnik, Shelley; Llorente, Carlin; Townsend, Eve; Hupert, Naomi; Dominguez, Ximena; VanderBorght, Mieke

2012-01-01

This study investigates whether a curriculum supplement organized as a sequence of teacher-led literacy activities using digital content from public educational television programs can improve early literacy outcomes of low-income preschoolers. The study sample was 436 children in 80 preschool classrooms in California and New York. Preschool…

The Impact of Education on Rural Women's Participation in Political and Economic Activities

ERIC Educational Resources Information Center

Bishaw, Alemayehu

2014-01-01

This study endeavored to investigate the impact of education on rural women's participation in political and economic activities. Six hundred rural women and 12 gender Activists were selected for this study from three Zones of Amhara Region, Ethiopia using multi-stage random sampling technique and purposeful sampling techniques respectively.…

Public-Private Partnership and Infrastructural Development in Nigerian Universities

ERIC Educational Resources Information Center

Oduwaiye, R. O.; Sofoluwe, A. O.; Bello, T. O.; Durosaro, I. A.

2014-01-01

This study investigated the degree to which Public-Private Partnership (PPP) services are related to infrastructural development in Nigerian Universities. The research design used was descriptive survey method. The population for the study encompassed all the 20 universities in South-west Nigeria. Stratified random sampling was used to select 12…

Exploring the Boundary Conditions of the Redundancy Principle

ERIC Educational Resources Information Center

McCrudden, Matthew T.; Hushman, Carolyn J.; Marley, Scott C.

2014-01-01

This experiment investigated whether study of a scientific text and a visual display that contained redundant text segments would affect memory and transfer. The authors randomly assigned 42 students from a university in the southwestern United States in equal numbers to 1 of 2 conditions: (a) a redundant condition, in which participants studied a…

Personal and Interpersonal Correlates of Bullying Behaviors among Korean Middle School Students

ERIC Educational Resources Information Center

Lee, Chang-Hun

2010-01-01

This study simultaneously investigates personal and interpersonal traits that were found to be important factors of bullying behavior using data collected from 1,238 randomly selected Korean middle school students. Using a modified and expanded definition of bullying based on a more culturally sensitive approach to bullying, this study categorizes…

Effects of Shuttlecock-Playing on Physical Fitness in College Students

ERIC Educational Resources Information Center

Zhang, Tingran; Luo, Jiong

2015-01-01

The purpose of this study was to investigate the exercise intensity and the physical fitness effect of shuttlecock playing. 18 normal body weight college students voluntarily participated in this study. They were randomly assigned to shuttlecock playing (SCP) and control groups. The SCP underwent a 15-week shuttlecock-playing program, but the…

Effective Teaching with ICT in Nigerian Higher Institutions: A Solution to Graduates' Unemployability

ERIC Educational Resources Information Center

Femi, Sunday Akinwumi; Yemisi, Etomi Edwin

2015-01-01

This study investigated effective teaching with the aid of ICT in Nigerian higher education institutions as a proposed solution to graduates' unemployability. The survey method was utilized for this study. Respondents were randomly selected from students and teachers of selected higher institutions in Nigeria. The findings reveal that, even though…

Racial/Ethnic Differences in Adults in Randomized Clinical Trials of Binge Eating Disorder

ERIC Educational Resources Information Center

Franko, Debra L.; Thompson-Brenner, Heather; Thompson, Douglas R.; Boisseau, Christina L.; Davis, Angela; Forbush, Kelsie T.; Roehrig, James P.; Bryson, Susan W.; Bulik, Cynthia M.; Crow, Scott J.; Devlin, Michael J.; Gorin, Amy A.; Grilo, Carlos M.; Kristeller, Jean L.; Masheb, Robin M.; Mitchell, James E.; Peterson, Carol B.; Safer, Debra L.; Striegel, Ruth H.; Wilfley, Denise E.; Wilson, G. Terence

2012-01-01

Objective: Recent studies suggest that binge eating disorder (BED) is as prevalent among African American and Hispanic Americans as among Caucasian Americans; however, data regarding the characteristics of treatment-seeking individuals from racial and ethnic minority groups are scarce. The purpose of this study was to investigate racial/ethnic…

Iranian University Students' Experiences of and Attitudes Towards Alternatives in Assessment

ERIC Educational Resources Information Center

Sadeghi, Karim; Abolfazli Khonbi, Zainab

2015-01-01

This study investigated the effect of assessment type (self vs. peer vs. teacher) on university students' academic achievement and students' attitudes toward them. In the main study, 82 undergraduate English-as-a-Foreign-Language students in four classes at three universities in Iran were randomly assigned into one of self-, peer- and…

Motivational Factors and Teachers Commitment in Public Secondary Schools in Mbale Municipality

ERIC Educational Resources Information Center

Olurotimi, Ogunlade Joseph; Asad, Kamonges Wahab; Abdulrauf, Abdulkadir

2015-01-01

The study investigated the influence of motivational factors on teachers' commitment in public Secondary School in Mbale Municipality. The study employed Cross-sectional survey design. The sampling technique used to select was simple random sampling technique. The instrument used to collect data was a self designed questionnaire. The data…

Effects of Activity Based Blended Learning Strategy on Prospective of Teachers' Achievement and Motivation

ERIC Educational Resources Information Center

Abdelraheem, Ahmed Yousif; Ahmed, Abdelrahman Mohammed

2015-01-01

The study investigates the effect of Activity based Blended Learning strategy and Conventional Blended Learning strategy on students' achievement and motivation. Two groups namely, experimental and control group from Sultan Qaboos University were selected randomly for the study. To assess students' achievement in the different groups, pre- and…

Examining the Relationships of Component Reading Skills to Reading Comprehension in Struggling Adult Readers

ERIC Educational Resources Information Center

Tighe, Elizabeth L.; Schatschneider, Christopher

2016-01-01

The current study employed a meta-analytic approach to investigate the relative importance of component reading skills to reading comprehension in struggling adult readers. A total of 10 component skills were consistently identified across 16 independent studies and 2,707 participants. Random effects models generated 76 predictor-reading…

The Effects on Students' Conceptual Understanding of Electric Circuits of Introducing Virtual Manipulatives within a Physical Manipulatives-Oriented Curriculum

ERIC Educational Resources Information Center

Zacharia, Zacharias C.; de Jong, Ton

2014-01-01

This study investigates whether Virtual Manipulatives (VM) within a Physical Manipulatives (PM)-oriented curriculum affect conceptual understanding of electric circuits and related experimentation processes. A pre-post comparison study randomly assigned 194 undergraduates in an introductory physics course to one of five conditions: three…

Sex Stereotypes and School Adolescents' Sexual Behaviour in Osun State, Nigeria

ERIC Educational Resources Information Center

Popoola, Bayode Isaiah

2011-01-01

This study investigated the association between sex stereotypes and the sexual behaviour of Nigerian school-going adolescents. It also ascertained the effects of age and sex on adolescents' beliefs about sex stereotypes. The study sample consisted of 658 (male = 287, female = 371) adolescents from nine randomly selected secondary schools in three…

Silent Illumination: A Study on Chan (Zen) Meditation, Anxiety, and Musical Performance Quality

ERIC Educational Resources Information Center

Lin, Peter; Chang, Joanne; Zemon, Vance; Midlarsky, Elizabeth

2008-01-01

This study investigated the effects of Chan (Zen) meditation on musical performance anxiety and musical performance quality. Nineteen participants were recruited from music conservatories and randomly assigned to either an eight-week meditation group or a wait-list control group. After the intervention, all participants performed in a public…

Male versus Female Attitudes toward Stuttering

ERIC Educational Resources Information Center

St. Louis, Kenneth O.

2012-01-01

Purpose: The study investigated the extent to which differences existed between public attitudes of males versus females. Method: One hundred adults, 50 males and 50 females, were chosen at random from each of 50 study samples comprising a total of 3371 respondents in a database archive who had completed the "Public Opinion Survey of Human…

Conflict Resolution Strategies in Non-Government Secondary Schools in Benue State, Nigeria

ERIC Educational Resources Information Center

Oboegbulem, Angie; Alfa, Idoko Alphonusu

2013-01-01

This study investigated perceived CRSs (conflict resolution strategies) for the resolution of conflicts in non-government secondary schools in Benue State, Nigeria. Three research questions and three hypotheses guided this study. Proportionate stratified random sampling technique was used in drawing 15% of the population which gave a total of 500…

Randomized controlled trial on the effects of CCTV training on quality of life, depression, and adaptation to vision loss.

PubMed

Burggraaff, Marloes C; van Nispen, Ruth M A; Knol, Dirk L; Ringens, Peter J; van Rens, Ger H M B

2012-06-14

In addition to performance-based measures, vision-related quality of life (QOL) and other subjective measures of psychosocial functioning are considered important outcomes of training in the visually impaired. In a multicenter, masked, randomized controlled trial, subjective effects of training in the use of closed-circuit televisions (CCTV) were investigated. Patients (n = 122) were randomized either to a treatment group that received usual delivery instructions from the supplier combined with concise outpatient training, or to a control group that received delivery instructions only. Subjective outcomes were the low vision quality-of-life questionnaire (LVQOL), EuroQOL 5 dimensions, adaptation to age-related vision loss (AVL), and the Center of Epidemiologic Studies Depression scales. Linear mixed models were used to investigate treatment effects. Differential effects of patient characteristics were studied by implementing higher order interactions into the models. From baseline to follow-up, all patients perceived significantly less problems on the reading and fine work dimension (-28.8 points; P < 0.001) and the adaptation dimension (-4.67 points; P = 0.04) of the LVQOL. However, no treatment effect was found based on the intention-to-treat analysis. This study demonstrated the effect of receiving and using a CCTV on two vision-related QOL dimensions; however, outpatient training in the use of CCTVs had no additional value. (trialregister.nl number, NTR1031.).

eEduHeart I: A Multicenter, Randomized, Controlled Trial Investigating the Effectiveness of a Cardiac Web-Based eLearning Platform - Rationale and Study Design.

PubMed

Frederix, Ines; Vandenberk, Thijs; Janssen, Leen; Geurden, Anne; Vandervoort, Pieter; Dendale, Paul

Cardiac telerehabilitation includes, in its most comprehensive format, telemonitoring, telecoaching, social interaction, and eLearning. The specific role of eLearning, however, was seldom assessed. The aim of eEduHeart I is to investigate the medium-term effectiveness of the addition of a cardiac web-based eLearing platform to conventional cardiac care. In this prospective, multicenter randomized, controlled trial, 1,000 patients with coronary artery disease will be randomized 1:1 to an intervention group (receiving 1-month unrestricted access to the cardiac eLearning platform in addition to conventional cardiac care) or to conventional cardiac care alone. The primary endpoint is health-related quality of life, assessed by the HeartQoL questionnaire at the 1- and 3-month follow-ups. Secondary endpoints include pathology-specific knowledge and self-reported eLearning platform user experience. Data on the eLearning platform usage will be gathered through web logging during the study period. eEduHeart I will be one of the first studies to report on the added value of eLearning. If the intervention is proven effective, current cardiac telerehabilitation programs can be augmented by including eLearning, too. The platform can then be used as a model for other chronic diseases in which patient education plays a key role. © 2016 S. Karger AG, Basel.

Treatment of asthma patients with herbal medicine TJ-96: a randomized controlled trial.

PubMed

Urata, Y; Yoshida, S; Irie, Y; Tanigawa, T; Amayasu, H; Nakabayashi, M; Akahori, K

2002-06-01

Alternative medicine use has increased at a remarkable pace all over the world in recent years. Although herbal medicine for the treatment of asthma is becoming the focus of public attention, randomized studies had not been performed, even in Eastern countries including Japan. This study was designed to investigate whether one of the Japanese government approved herbal complexes Saiboku-to (TJ-96) is effective for the treatment of atopic asthma, and to investigate whether this protective activity is associated with a reduction in eosinophilic inflammation. A double-blind, randomized, crossover design was used. Subjects received 2.5 g of TJ-96 or placebo orally 3 times daily for 4 weeks and then, after a washout period of at least 4 weeks, crossed over to receive the alternative treatment. We assessed the effects of pretreatment with TJ-96 on bronchoconstriction precipitated by inhalation of methacholine. Furthermore, eosinophil counts and measurement of eosinophilic cationic protein (ECP) were performed. After 4 weeks of treatment with TJ-96, values of PC20 -methacholine significantly improved in the treatment with TJ-96. Also, patients' symptoms, blood eosinophils, serum ECP, sputum eosinophils, and sputum ECP were significantly decreased. Our results suggest that TJ-96 has an antiinflammatory effect on bronchial eosinophilic infiltration. This study raises further interesting therapeutic possibilities and argues for further trials of new approaches to the treatment of asthma.

Random wandering of laser beams with orbital angular momentum during propagation through atmospheric turbulence.

PubMed

Aksenov, Valerii P; Kolosov, Valeriy V; Pogutsa, Cheslav E

2014-06-10

The propagation of laser beams having orbital angular momenta (OAM) in the turbulent atmosphere is studied numerically. The variance of random wandering of these beams is investigated with the use of the Monte Carlo technique. It is found that, among various types of vortex laser beams, such as the Laguerre-Gaussian (LG) beam, modified Bessel-Gaussian beam, and hypergeometric Gaussian beam, having identical initial effective radii and OAM, the LG beam occupying the largest effective volume in space is the most stable one.

Low power consumption resistance random access memory with Pt/InOx/TiN structure

NASA Astrophysics Data System (ADS)

Yang, Jyun-Bao; Chang, Ting-Chang; Huang, Jheng-Jie; Chen, Yu-Ting; Tseng, Hsueh-Chih; Chu, Ann-Kuo; Sze, Simon M.; Tsai, Ming-Jinn

2013-09-01

In this study, the resistance switching characteristics of a resistive random access memory device with Pt/InOx/TiN structure is investigated. Unstable bipolar switching behavior is observed during the initial switching cycle, which then stabilizes after several switching cycles. Analyses indicate that the current conduction mechanism in the resistance state is dominated by Ohmic conduction. The decrease in electrical conductance can be attributed to the reduction of the cross-sectional area of the conduction path. Furthermore, the device exhibits low operation voltage and power consumption.

Plasmonic modes and extinction properties of a random nanocomposite cylinder

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

Moradi, Afshin, E-mail: a.moradi@kut.ac.ir

We study the properties of surface plasmon-polariton waves of a random metal-dielectric nanocomposite cylinder, consisting of bulk metal embedded with dielectric nanoparticles. We use the Maxwell-Garnett formulation to model the effective dielectric function of the composite medium and show that there exist two surface mode bands. We investigate the extinction properties of the system, and obtain the dependence of the extinction spectrum on the nanoparticles’ shape and concentration as well as the cylinder radius and the incidence angle for both TE and TM polarization.

Investigation of the performance characteristics of Doppler radar technique for aircraft collision hazard warning, phase 3

NASA Technical Reports Server (NTRS)

1972-01-01

System studies, equipment simulation, hardware development and flight tests which were conducted during the development of aircraft collision hazard warning system are discussed. The system uses a cooperative, continuous wave Doppler radar principle with pseudo-random frequency modulation. The report presents a description of the system operation and deals at length with the use of pseudo-random coding techniques. In addition, the use of mathematical modeling and computer simulation to determine the alarm statistics and system saturation characteristics in terminal area traffic of variable density is discussed.

Transport characteristics in Au/pentacene/Au diodes

NASA Astrophysics Data System (ADS)

Hayashi, Toshiaki; Naka, Akiyoshi; Hiroki, Masanobu; Yokota, Tomoyuki; Someya, Takao; Fujiwara, Akira

2018-03-01

We have used scanning and transmission electron microscopes (SEM and TEM) to study the structure of a pentacene thin film grown on a Au layer with and shown that it consists of randomly oriented amorphous pentacene clusters. We have also investigated the transport properties of amorphous pentacene in a metal-semiconductor-metal (MSM) diode structure and shown that the current is logarithmically proportional to the square root of the applied voltage, which indicates that transport occurs as the result of hopping between localized sites randomly distributed in space and energy.

Travelling Randomly on the Poincaré Half-Plane with a Pythagorean Compass

NASA Astrophysics Data System (ADS)

Cammarota, V.; Orsingher, E.

2008-02-01

A random motion on the Poincaré half-plane is studied. A particle runs on the geodesic lines changing direction at Poisson-paced times. The hyperbolic distance is analyzed, also in the case where returns to the starting point are admitted. The main results concern the mean hyperbolic distance (and also the conditional mean distance) in all versions of the motion envisaged. Also an analogous motion on orthogonal circles of the sphere is examined and the evolution of the mean distance from the starting point is investigated.

Damage spreading in spatial and small-world random Boolean networks

NASA Astrophysics Data System (ADS)

Lu, Qiming; Teuscher, Christof

2014-02-01

The study of the response of complex dynamical social, biological, or technological networks to external perturbations has numerous applications. Random Boolean networks (RBNs) are commonly used as a simple generic model for certain dynamics of complex systems. Traditionally, RBNs are interconnected randomly and without considering any spatial extension and arrangement of the links and nodes. However, most real-world networks are spatially extended and arranged with regular, power-law, small-world, or other nonrandom connections. Here we explore the RBN network topology between extreme local connections, random small-world, and pure random networks, and study the damage spreading with small perturbations. We find that spatially local connections change the scaling of the Hamming distance at very low connectivities (K¯≪1) and that the critical connectivity of stability Ks changes compared to random networks. At higher K¯, this scaling remains unchanged. We also show that the Hamming distance of spatially local networks scales with a power law as the system size N increases, but with a different exponent for local and small-world networks. The scaling arguments for small-world networks are obtained with respect to the system sizes and strength of spatially local connections. We further investigate the wiring cost of the networks. From an engineering perspective, our new findings provide the key design trade-offs between damage spreading (robustness), the network's wiring cost, and the network's communication characteristics.

Cannabinoid-induced effects on the nociceptive system: a neurophysiological study in patients with secondary progressive multiple sclerosis.

PubMed

Conte, Antonella; Bettolo, Chiara Marini; Onesti, Emanuela; Frasca, Vittorio; Iacovelli, Elisa; Gilio, Francesca; Giacomelli, Elena; Gabriele, Maria; Aragona, Massimiliano; Tomassini, Valentina; Pantano, Patrizia; Pozzilli, Carlo; Inghilleri, Maurizio

2009-05-01

Although clinical studies show that cannabinoids improve central pain in patients with multiple sclerosis (MS) neurophysiological studies are lacking to investigate whether they also suppress these patients' electrophysiological responses to noxious stimulation. The flexion reflex (FR) in humans is a widely used technique for assessing the pain threshold and for studying spinal and supraspinal pain pathways and the neurotransmitter system involved in pain control. In a randomized, double-blind, placebo-controlled, cross-over study we investigated cannabinoid-induced changes in RIII reflex variables (threshold, latency and area) in a group of 18 patients with secondary progressive MS. To investigate whether cannabinoids act indirectly on the nociceptive reflex by modulating lower motoneuron excitability we also evaluated the H-reflex size after tibial nerve stimulation and calculated the H wave/M wave (H/M) ratio. Of the 18 patients recruited and randomized 17 completed the study. After patients used a commercial delta-9-tetrahydrocannabinol (THC) and cannabidiol mixture as an oromucosal spray the RIII reflex threshold increased and RIII reflex area decreased. The visual analogue scale score for pain also decreased, though not significantly. Conversely, the H/M ratio measured before patients received cannabinoids remained unchanged after therapy. In conclusion, the cannabinoid-induced changes in the RIII reflex threshold and area in patients with MS provide objective neurophysiological evidence that cannabinoids modulate the nociceptive system in patients with MS.

Modeling fluid diffusion in cerebral white matter with random walks in complex environments

NASA Astrophysics Data System (ADS)

Levy, Amichai; Cwilich, Gabriel; Buldyrev, Sergey V.; Weeden, Van J.

2012-02-01

Recent studies with diffusion MRI have shown new aspects of geometric order in the brain, including complex path coherence within the cerebral cortex, and organization of cerebral white matter and connectivity across multiple scales. The main assumption of these studies is that water molecules diffuse along myelin sheaths of neuron axons in the white matter and thus the anisotropy of their diffusion tensor observed by MRI can provide information about the direction of the axons connecting different parts of the brain. We model the diffusion of particles confined in the space of between the bundles of cylindrical obstacles representing fibrous structures of various orientations. We have investigated the directional properties of the diffusion, by studying the angular distribution of the end point of the random walks as a function of their length, to understand the scale over which the distribution randomizes. We will show evidence of qualitative change in the behavior of the diffusion for different volume fractions of obstacles. Comparisons with three-dimensional MRI images will be illustrated.

Nonlinear complexity of random visibility graph and Lempel-Ziv on multitype range-intensity interacting financial dynamics

NASA Astrophysics Data System (ADS)

Zhang, Yali; Wang, Jun

2017-09-01

In an attempt to investigate the nonlinear complex evolution of financial dynamics, a new financial price model - the multitype range-intensity contact (MRIC) financial model, is developed based on the multitype range-intensity interacting contact system, in which the interaction and transmission of different types of investment attitudes in a stock market are simulated by viruses spreading. Two new random visibility graph (VG) based analyses and Lempel-Ziv complexity (LZC) are applied to study the complex behaviors of return time series and the corresponding random sorted series. The VG method is the complex network theory, and the LZC is a non-parametric measure of complexity reflecting the rate of new pattern generation of a series. In this work, the real stock market indices are considered to be comparatively studied with the simulation data of the proposed model. Further, the numerical empirical study shows the similar complexity behaviors between the model and the real markets, the research confirms that the financial model is reasonable to some extent.

Peer Influence, Genetic Propensity, and Binge Drinking: A Natural Experiment and a Replication.

PubMed

Guo, Guang; Li, Yi; Wang, Hongyu; Cai, Tianji; Duncan, Greg J

2015-11-01

The authors draw data from the College Roommate Study (ROOM) and the National Longitudinal Study of Adolescent Health to investigate gene-environment interaction effects on youth binge drinking. In ROOM, the environmental influence was measured by the precollege drinking behavior of randomly assigned roommates. Random assignment safeguards against friend selection and removes the threat of gene-environment correlation that makes gene-environment interaction effects difficult to interpret. On average, being randomly assigned a drinking peer as opposed to a nondrinking peer increased college binge drinking by 0.5-1.0 episodes per month, or 20%-40% the average amount of binge drinking. However, this peer influence was found only among youths with a medium level of genetic propensity for alcohol use; those with either a low or high genetic propensity were not influenced by peer drinking. A replication of the findings is provided in data drawn from Add Health. The study shows that gene-environment interaction analysis can uncover social-contextual effects likely to be missed by traditional sociological approaches.

Change in Pulmonary Function after Incentive Spirometer Exercise in Children with Spastic Cerebral Palsy: A Randomized Controlled Study.

PubMed

Choi, Ja Young; Rha, Dong-wook; Park, Eun Sook

2016-05-01

The aim of this study was to investigate the effect of incentive spirometer exercise (ISE) on pulmonary function and maximal phonation time (MPT) in children with spastic cerebral palsy (CP). Fifty children with CP were randomly assigned to two groups: the experimental group and the control group. Both groups underwent comprehensive rehabilitation therapy. The experimental group underwent additional ISE. The forced vital capacity (FVC), forced expiratory volume at one second (FEV₁), FEV₁/FVC ratio, peak expiratory flow (PEF), and MPT were assessed as outcome measures before and after 4 weeks of training. There were significant improvements in FVC, FEV₁, PEF, and MPT in the experimental group, but not in the control group. In addition, the improvements in FVC, FEV₁, and MPT were significantly greater in the experimental group than in the control group. The results of this randomized controlled study support the use of ISE for enhancing pulmonary function and breath control for speech production in children with CP.

Effect of berberine on insulin resistance in women with polycystic ovary syndrome: study protocol for a randomized multicenter controlled trial.

PubMed

Li, Yan; Ma, Hongli; Zhang, Yuehui; Kuang, Hongying; Ng, Ernest Hung Yu; Hou, Lihui; Wu, Xiaoke

2013-07-18

Insulin resistance and hyperinsulinemia play a key role in the pathogenesis of polycystic ovary syndrome (PCOS), which is characterized by hyperandrogenism, ovulatory dysfunction, and presence of polycystic ovaries on pelvic scanning. Insulin resistance is significantly associated with the long-term risks of metabolic syndrome and cardiovascular disease. Berberine has effects on insulin resistance but its use in women with PCOS has not been fully investigated. In this paper, we present a research design evaluating the effects of berberine on insulin resistance in women with PCOS. This is a multicenter, randomized, placebo-controlled and double-blind trial. A total of 120 patients will be enrolled in this study and will be randomized into two groups. Berberine or placebo will be taken orally for 12 weeks. The primary outcome is the whole body insulin action assessed with the hyperinsulinemic-euglycemic clamp. We postulate that women with PCOS will have improved insulin resistance following berberine administration. This study is registered at ClinicalTrials.gov, NCT01138930.

[Krigle estimation and its simulated sampling of Chilo suppressalis population density].

PubMed

Yuan, Zheming; Bai, Lianyang; Wang, Kuiwu; Hu, Xiangyue

2004-07-01

In order to draw up a rational sampling plan for the larvae population of Chilo suppressalis, an original population and its two derivative populations, random population and sequence population, were sampled and compared with random sampling, gap-range-random sampling, and a new systematic sampling integrated Krigle interpolation and random original position. As for the original population whose distribution was up to aggregative and dependence range in line direction was 115 cm (6.9 units), gap-range-random sampling in line direction was more precise than random sampling. Distinguishing the population pattern correctly is the key to get a better precision. Gap-range-random sampling and random sampling are fit for aggregated population and random population, respectively, but both of them are difficult to apply in practice. Therefore, a new systematic sampling named as Krigle sample (n = 441) was developed to estimate the density of partial sample (partial estimation, n = 441) and population (overall estimation, N = 1500). As for original population, the estimated precision of Krigle sample to partial sample and population was better than that of investigation sample. With the increase of the aggregation intensity of population, Krigel sample was more effective than investigation sample in both partial estimation and overall estimation in the appropriate sampling gap according to the dependence range.

Investigation of the contextual interference effect in the manipulation of the motor parameter of over-all force.

PubMed

Goodwin, J E; Meeuwsen, H J

1996-12-01

This investigation examined the contextual interference effect when manipulating over-all force in a golf-putting task. Undergraduate women (N = 30) were randomly assigned to a Random, Blocked-Random, or Blocked practice condition and practiced golf putting from distances of 2.43 m, 3.95 m, and 5.47 m during acquisition. Subjects in the Random condition practiced trials in a quasirandom sequence and those in the Blocked-Random condition practiced trials initially in a blocked sequence with the remainder of the trials practiced in a quasirandom sequence. In the Blocked condition subjects practiced trials in a blocked sequence. A 24-hr. transfer test consisted of 30 trials with 10 trials each from 1.67 m, 3.19 m, and 6.23 m. Transfer scores supported the Magill and Hall (1990) hypothesis that, when task variations involve learning parameters of a generalized motor program, the benefit of random practice over blocked practice would not be found.

EARLYDRAIN- outcome after early lumbar CSF-drainage in aneurysmal subarachnoid hemorrhage: study protocol for a randomized controlled trial.

PubMed

Bardutzky, Jürgen; Witsch, Jens; Jüttler, Eric; Schwab, Stefan; Vajkoczy, Peter; Wolf, Stefan

2011-09-14

Aneurysmal subarachnoid hemorrhage (SAH) may be complicated by delayed cerebral ischemia, which is a major cause of unfavorable clinical outcome and death in SAH-patients. Delayed cerebral ischemia is presumably related to the development of vasospasm triggered by the presence of blood in the basal cisterns. To date, oral application of the calcium antagonist nimodipine is the only prophylactic treatment for vasospasm recognized under international guidelines.In retrospective trials lumbar drainage of cerebrospinal fluid has been shown to be a safe and feasible measure to remove the blood from the basal cisterns and decrease the incidence of delayed cerebral ischemia and vasospasm in the respective study populations. However, the efficacy of lumbar drainage has not been evaluated prospectively in a randomized controlled trial yet. This is a protocol for a 2-arm randomized controlled trial to compare an intervention group receiving early continuous lumbar CSF-drainage and standard neurointensive care to a control group receiving standard neurointensive care only. Adults suffering from a first aneurysmal subarachnoid hemorrhage whose aneurysm has been secured by means of coiling or clipping are eligible for trial participation. The effect of early CSF drainage (starting < 72 h after securing the aneurysm) will be measured in the following ways: the primary endpoint will be disability after 6 months, assessed by a blinded investigator during a personal visit or standardized telephone interview using the modified Rankin Scale. Secondary endpoints include mortality after 6 months, angiographic vasospasm, transcranial Doppler sonography (TCD) mean flow velocity in both middle cerebral arteries and rate of shunt insertion at 6 months after hospital discharge. Here, we present the study design of a multicenter prospective randomized controlled trial to investigate whether early application of a lumbar drainage improves clinical outcome after aneurysmal subarachnoid hemorrhage.

Study protocol: to investigate effects of highly specialized rehabilitation for patients with multiple sclerosis. A randomized controlled trial of a personalized, multidisciplinary intervention

PubMed Central

2012-01-01

Background Multiple sclerosis (MS) is a complex, chronic and progressive disease and rehabilitation services can provide important support to patients. Few MS rehabilitation programs have been shown to provide health improvements to patients in a cost-effective manner. The objective of this study is to assess the effects in terms of changes measured by a variety of standardized quality of life, mastery, coping, compliance and individual goal-related endpoints. This combination provides the basis for analyzing the complexity of MS and outcomes of a personalized rehabilitation. Methods/Design Patients with MS referred to hospital rehabilitation services will be randomized to either early admission (within two months) or usual admission (after an average waiting time of eight months). They will complete a battery of standardized health outcome instruments prior to randomization, and again six and twelve months after randomization, and a battery of goal-related outcome measures at admission and discharge, and again one, six and twelve months after randomization. Discussion The results of the study are expected to contribute to further development of MS rehabilitation services and to discussions about the design and content of such services. The results will also provide additional information to health authorities responsible for providing and financing rehabilitation services. Trial registration Current Controlled Trials (ISRCTN05245917) PMID:22954027

Endurance exercise beneficially affects ambulatory blood pressure: a systematic review and meta-analysis.

PubMed

Cornelissen, Véronique A; Buys, Roselien; Smart, Neil A

2013-04-01

Exercise is widely recommended as one of the key preventive lifestyle changes to reduce the risk of hypertension and to manage high blood pressure (BP), but individual studies investigating the effect of exercise on ambulatory BP have remained inconclusive. Therefore, the primary purpose of this systematic review and meta-analysis was to determine the effect of aerobic endurance training on daytime and night-time BP in healthy adults. A systematic literature search was conducted using PubMed and Cochrane Controlled Clinical trial registry from their inception to May 2012. Randomized controlled trials of at least 4 weeks investigating the effects of aerobic endurance training on ambulatory BP in healthy adults were included. Inverse weighted random effects models were used for analyses, with data reported as weighted means and 95% confidence limits. We included 15 randomized controlled trials, involving 17 study groups and 633 participants (394 exercise participants and 239 control participants). Overall, endurance training induced a significant reduction in daytime SBP [-3.2 mmHg, 95% confidence interval (CI), -5.0 to-1.3] and daytime DBP (-2.7 mmHg, 95% CI, -3.9 to -1.5). No effect was observed on night-time BP. The findings from this meta-analysis suggest that aerobic endurance exercise significantly decreases daytime, but not night-time, ambulatory BP.

Blinded interpretation of study results can feasibly and effectively diminish interpretation bias.

PubMed

Järvinen, Teppo L N; Sihvonen, Raine; Bhandari, Mohit; Sprague, Sheila; Malmivaara, Antti; Paavola, Mika; Schünemann, Holger J; Guyatt, Gordon H

2014-07-01

Controversial and misleading interpretation of data from randomized trials is common. How to avoid misleading interpretation has received little attention. Herein, we describe two applications of an approach that involves blinded interpretation of the results by study investigators. The approach involves developing two interpretations of the results on the basis of a blinded review of the primary outcome data (experimental treatment A compared with control treatment B). One interpretation assumes that A is the experimental intervention and another assumes that A is the control. After agreeing that there will be no further changes, the investigators record their decisions and sign the resulting document. The randomization code is then broken, the correct interpretation chosen, and the manuscript finalized. Review of the document by an external authority before finalization can provide another safeguard against interpretation bias. We found the blinded preparation of a summary of data interpretation described in this article practical, efficient, and useful. Blinded data interpretation may decrease the frequency of misleading data interpretation. Widespread adoption of blinded data interpretation would be greatly facilitated were it added to the minimum set of recommendations outlining proper conduct of randomized controlled trials (eg, the Consolidated Standards of Reporting Trials statement). Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Psychiatric Resident and Attending Diagnostic and Prescribing Practices

ERIC Educational Resources Information Center

Tripp, Adam C.; Schwartz, Thomas L.

2008-01-01

Objective: This study investigates whether two patient population groups, under resident or attending treatment, are equivalent or different in the distribution of patient characteristics, diagnoses, or pharmacotherapy. Methods: Demographic data, psychiatric diagnoses, and pharmacotherapy data were collected for 100 random patient charts of…

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

Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12®-supplemented yogurt in healthy children

PubMed Central

Tan, Tina P.; Ba, Zhaoyong; Sanders, Mary Ellen; D’Amico, Frank J.; Roberts, Robert F.; Smith, Keisha Herbin; Merenstein, Daniel J.

2016-01-01

Objectives Probiotics are live microorganisms that may provide health benefits to the individual when consumed in sufficient quantities. For studies conducted on health or disease endpoints on probiotics in the United States, the Food and Administration (FDA) has required those studies to be conducted as investigational new drugs. This phase I, double-blinded, randomized, controlled safety study represents the first requirement of this pathway. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12® (BB-12®)-supplemented yogurt when consumed by a generally healthy group of children. The secondary aim was to assess the effect of BB-12®-supplemented yogurt on the gut microbiota of the children. Methods Sixty children aged 1–5 years were randomly assigned to consume four ounces of either BB-12®-supplemented yogurt or non-supplemented control yogurt daily for 10 days. The primary outcome was to assess safety and tolerability, as determined by the number of reported adverse events. Results A total of 186 non-serious adverse events were reported, with no significant differences between the control and BB-12® groups. No significant changes due to probiotic treatment were observed in the gut microbiota of the study cohort. Conclusions BB-12®-supplemented yogurt is safe and well-tolerated when consumed by healthy children. This study will form the basis for future randomized clinical trials investigating the potential effects of BB-12®-supplemented yogurt in different disease states. PMID:28114246

Using Behavioral Analytics to Increase Exercise: A Randomized N-of-1 Study.

PubMed

Yoon, Sunmoo; Schwartz, Joseph E; Burg, Matthew M; Kronish, Ian M; Alcantara, Carmela; Julian, Jacob; Parsons, Faith; Davidson, Karina W; Diaz, Keith M

2018-04-01

This intervention study used mobile technologies to investigate whether those randomized to receive a personalized "activity fingerprint" (i.e., a one-time tailored message about personal predictors of exercise developed from 6 months of observational data) increased their physical activity levels relative to those not receiving the fingerprint. A 12-month randomized intervention study. From 2014 to 2015, 79 intermittent exercisers had their daily physical activity assessed by accelerometry (Fitbit Flex) and daily stress experience, a potential predictor of exercise behavior, was assessed by smartphone. Data collected during the first 6 months of observation were used to develop a person-specific "activity fingerprint" (i.e., N-of-1) that was subsequently sent via email on a single occasion to randomized participants. Pre-post changes in the percentage of days exercised were analyzed within and between control and intervention groups. The control group significantly decreased their proportion of days exercised (10.5% decrease, p<0.0001) following randomization. By contrast, the intervention group showed a nonsignificant decrease in the proportion of days exercised (4.0% decrease, p=0.14). Relative to the decrease observed in the control group, receipt of the activity fingerprint significantly increased the likelihood of exercising in the intervention group (6.5%, p=0.04). This N-of-1 intervention study demonstrates that a one-time brief message conveying personalized exercise predictors had a beneficial effect on exercise behavior among urban adults. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Using a partially randomized patient preference study design to evaluate the therapeutic effect of acupuncture and cupping therapy for fibromyalgia: study protocol for a partially randomized controlled trial.

PubMed

Cao, Hui-Juan; Liu, Jian-Ping; Hu, Hui; Wang, Nissi S

2014-07-10

Conducting randomized controlled trials on traditional Chinese non-drug therapies has been limited by factors such as patient preference to specific treatment modality. The aim of this study is to investigate the feasibility of applying a partially randomized patient preference (PRPP) trial model in evaluating the efficacy of two types of traditional Chinese medicine therapies, acupuncture and cupping, for fibromyalgia while accounting for patients' preference of either therapeutic modality. This protocol was approved by the Institutional Ethics Committee of affiliated Dongfang Hospital, Beijing University of Chinese Medicine (approval number: 2013052104-2). One hundred participants with fibromyalgia will be included in this study. Diagnosis of fibromyalgia will be based on the American College of Rheumatology criteria. Before treatment, participants will be interviewed for their preference toward acupuncture or cupping therapy. Fifty participants with no preference will be randomly assigned to one of the two groups and another 50 participants with strong preference to either acupuncture or cupping will receive what they choose. For acupuncture and cupping therapy, the main acupoints used will be tender points (Ashi). Treatment will be three times a week for 5 consecutive weeks with a follow-up period of 12 weeks. Outcome measures will be qualitative (patient expectation and satisfaction) and quantitative (pain intensity, quality of life, depression assessment). NCT01869712 (in clinicaltrials.gov, on 22nd May 2013).

Using a partially randomized patient preference study design to evaluate the therapeutic effect of acupuncture and cupping therapy for fibromyalgia: study protocol for a partially randomized controlled trial

PubMed Central

2014-01-01

Background Conducting randomized controlled trials on traditional Chinese non-drug therapies has been limited by factors such as patient preference to specific treatment modality. The aim of this study is to investigate the feasibility of applying a partially randomized patient preference (PRPP) trial model in evaluating the efficacy of two types of traditional Chinese medicine therapies, acupuncture and cupping, for fibromyalgia while accounting for patients’ preference of either therapeutic modality. Methods This protocol was approved by the Institutional Ethics Committee of affiliated Dongfang Hospital, Beijing University of Chinese Medicine (approval number: 2013052104-2). One hundred participants with fibromyalgia will be included in this study. Diagnosis of fibromyalgia will be based on the American College of Rheumatology criteria. Before treatment, participants will be interviewed for their preference toward acupuncture or cupping therapy. Fifty participants with no preference will be randomly assigned to one of the two groups and another 50 participants with strong preference to either acupuncture or cupping will receive what they choose. For acupuncture and cupping therapy, the main acupoints used will be tender points (Ashi). Treatment will be three times a week for 5 consecutive weeks with a follow-up period of 12 weeks. Outcome measures will be qualitative (patient expectation and satisfaction) and quantitative (pain intensity, quality of life, depression assessment). Trial registration number NCT01869712 (in clinicaltrials.gov, on 22nd May 2013). PMID:25012121

Meta-analysis of two studies in the presence of heterogeneity with applications in rare diseases.

PubMed

Friede, Tim; Röver, Christian; Wandel, Simon; Neuenschwander, Beat

2017-07-01

Random-effects meta-analyses are used to combine evidence of treatment effects from multiple studies. Since treatment effects may vary across trials due to differences in study characteristics, heterogeneity in treatment effects between studies must be accounted for to achieve valid inference. The standard model for random-effects meta-analysis assumes approximately normal effect estimates and a normal random-effects model. However, standard methods based on this model ignore the uncertainty in estimating the between-trial heterogeneity. In the special setting of only two studies and in the presence of heterogeneity, we investigate here alternatives such as the Hartung-Knapp-Sidik-Jonkman method (HKSJ), the modified Knapp-Hartung method (mKH, a variation of the HKSJ method) and Bayesian random-effects meta-analyses with priors covering plausible heterogeneity values; R code to reproduce the examples is presented in an appendix. The properties of these methods are assessed by applying them to five examples from various rare diseases and by a simulation study. Whereas the standard method based on normal quantiles has poor coverage, the HKSJ and mKH generally lead to very long, and therefore inconclusive, confidence intervals. The Bayesian intervals on the whole show satisfying properties and offer a reasonable compromise between these two extremes. © 2016 The Authors. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

78 FR 35645 - Certain Static Random Access Memories and Products Containing Same; Commission Determination...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-13

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-792] Certain Static Random Access Memories and Products Containing Same; Commission Determination Affirming a Final Initial Determination..., and the sale within the United States after importation of certain static random access memories and...

A Randomized, Double-Blind, Placebo-Controlled Study of the Effect of a High-Potency Topical Corticosteroid After Sclerotherapy for Reticular and Telangiectatic Veins of the Lower Extremities.

PubMed

Friedmann, Daniel P; Liolios, Ana M; Wu, Douglas C; Goldman, Mitchel P; Eimpunth, Sasima

2015-10-01

Although typically mild, transient, and expected, most adverse events (AEs) postsclerotherapy are inflammatory in nature. To evaluate the effects of a high-potency topical corticosteroid (TC) applied immediately postsclerotherapy. Subjects undergoing bilateral lower extremity sclerotherapy with polidocanol had extremities randomized to a single application of betamethasone dipropionate and placebo saline solutions immediately post-treatment in a double-blind manner. Adverse events were assessed for each extremity by subjects at t = 0 (preapplication) and t = 15 (15 minutes postapplication) and by an investigator at t = 0 and t = 15, and at Days 14 and 60. Subjects and investigator evaluated efficacy with a quartile improvement scale. Sixteen female subjects completed the study. Subjects reported no statistically significant differences in AEs between TC and placebo at either t = 0 or t = 15. Investigator scores for erythema and swelling/urtication were not significantly different between groups at the same time points. Although most subjects demonstrated 26% to 75% improvement at Day 60, results were not significantly different between extremities on subject and investigator evaluation. High-potency TC application immediately postsclerotherapy produced no statistically significant differences in subject- and investigator-assessed AEs and clearance rates compared with placebo. Foam sclerotherapy with polidocanol is safe and effective for the treatment of lower extremity reticular veins.

Investigation of the Effectiveness of Teacher-Education Curriculum in Primary School Mathematics in Tanzania Mainland. African Studies in Curriculum Development & Evaluation. No. 64.

ERIC Educational Resources Information Center

Masota, Laurent Anatoly

An investigation was made of the effectiveness of the teacher education curriculum for primary school mathematics teachers in Tanzania. Subjects were a random sample of 8 teacher trainees in each of 4 selected colleges, as well as 4 school principals, 12 tutors, and 16 serving teachers. Data were gathered by means of questionnaires and…

A Cross-Cultural Investigation of Gender-Bound Language Use in Turkish and English Plays: Implications for Foreign Language Education

ERIC Educational Resources Information Center

Genc, Zubeyde Sinem; Armagan, Kiymet Selin

2018-01-01

The aim of the study is to investigate gender-bound language use in Turkish and English languages and to identify the differences and similarities across cultures and genders in the plays with family and social themes. Four English and five Turkish plays were chosen randomly for comparison. The number of words in the plays were taken into…

Studies Of Single-Event-Upset Models

NASA Technical Reports Server (NTRS)

Zoutendyk, J. A.; Smith, L. S.; Soli, G. A.

1988-01-01

Report presents latest in series of investigations of "soft" bit errors known as single-event upsets (SEU). In this investigation, SEU response of low-power, Schottky-diode-clamped, transistor/transistor-logic (TTL) static random-access memory (RAM) observed during irradiation by Br and O ions in ranges of 100 to 240 and 20 to 100 MeV, respectively. Experimental data complete verification of computer model used to simulate SEU in this circuit.

Aquatic Physical Therapy for Children with Developmental Coordination Disorder: A Pilot Randomized Controlled Trial

ERIC Educational Resources Information Center

Hillier, Susan; McIntyre, Auburn; Plummer, Leanne

2010-01-01

Aquatic therapy is an intervention for children with Developmental Coordination Disorder (DCD) that has not been investigated formally. This was a pilot randomized controlled trial to investigate the feasibility and preliminary effectiveness of an aquatic therapy program to improve motor skills of children with DCD. Thirteen children (mean age 7…

Partial transpose of random quantum states: Exact formulas and meanders

NASA Astrophysics Data System (ADS)

Fukuda, Motohisa; Śniady, Piotr

2013-04-01

We investigate the asymptotic behavior of the empirical eigenvalues distribution of the partial transpose of a random quantum state. The limiting distribution was previously investigated via Wishart random matrices indirectly (by approximating the matrix of trace 1 by the Wishart matrix of random trace) and shown to be the semicircular distribution or the free difference of two free Poisson distributions, depending on how dimensions of the concerned spaces grow. Our use of Wishart matrices gives exact combinatorial formulas for the moments of the partial transpose of the random state. We find three natural asymptotic regimes in terms of geodesics on the permutation groups. Two of them correspond to the above two cases; the third one turns out to be a new matrix model for the meander polynomials. Moreover, we prove the convergence to the semicircular distribution together with its extreme eigenvalues under weaker assumptions, and show large deviation bound for the latter.

Practice schedule and acquisition, retention, and transfer of a throwing task in 6-yr.-old children.

PubMed

Granda Vera, Juan; Montilla, Mariano Medina

2003-06-01

Earlier studies have raised questions about the usefulness of variable and random practice in learning motor tasks so this study was designed to investigate the effects of contextual interference in young children, and specifically to evaluate the effectiveness of variable or random practice structure in 6-yr.-old boys and girls. Participants on a variable practice schedule showed better performances than those on a blocked schedule. The differences between the two groups were significant in the acquisition, retention, and transfer phases. These results support the hypothesis that contextual interference enhances skill learning. Because the study involved groups of young children in the setting of their normally scheduled physical education class, the practical applications of the results are evident.

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.

Effects of Practical Activities and Manual on Science Students' Academic Performance on Solubility in Uruan Local Education Authority of Akwa Ibom State

ERIC Educational Resources Information Center

Etiubon, Rebecca Ufonabasi; Udoh, Nsimeneabasi Michael

2017-01-01

This study investigated the effects of practical activities and manual on science students' academic performance on solubility in Uruan Local Education Authority of Akwa Ibom State. The study adopted pretest, posttest non randomized quasi experimental design. Three research questions and three hypotheses were formulated to guide the study. One…

Principals Leadership Styles and Gender Influence on Teachers Morale in Public Secondary Schools

ERIC Educational Resources Information Center

Eboka, Obiajulu Chinyelum

2016-01-01

The study investigated the perception of teachers on the influence of principals' leadership styles and gender on teacher morale. Four research questions and four research hypotheses guided the study. An ex-post facto research design was adopted in the study. Through the simple random sampling technique a total of 72 principals and 2,506 in 72…

Using Relevance Prompts: An Exploratory Study to Promote Eighth Graders' Comprehension and Retelling of Narrative Text

ERIC Educational Resources Information Center

Fogarty, Melissa S.; Davis, John L.; Anderson, Leah L.; Myint, Ahmarlay

2017-01-01

This exploratory study investigated the effects of modifying eighth grade students' purposes for reading through a prompt designed to increase engagement with the text. The current study was conducted using a randomized between-subjects design, with a relevance prompt as the between-subjects factor and reader proficiency as a covariate. A sample…

Implementation of Quality Assurance Standards and Principals' Administrative Effectiveness in Public Secondary Schools in Edo and Delta States

ERIC Educational Resources Information Center

Momoh, U.; Osagiobare, Emmanuel Osamiro

2015-01-01

The study investigated principals' implementation of quality assurance standards and administrative effectiveness in public secondary schools in Edo and Delta States. To guide the study, four research questions and hypotheses were raised. Descriptive research design was adopted for the study and the simple random sampling technique was used to…

Investigating EFL Teachers' Conceptions and Literacy of Formative Assessment: Constructing and Validating an Inventory

ERIC Educational Resources Information Center

Khodabakhshzadeh, Hossein; Kafi, Zahra; Hosseinnia, Mansooreh

2018-01-01

The present study aimed at constructing a formative assessment inventory for assessing EFL instructors' conception and literacy about the issue under study. Therefore, 302 male and female Iranian EFL teachers took part in the study in a random way to fill out the researcher made questionnaire. The first draft of the scale consisted of two main…

A Study of the Relationship between Academic Achievement Motivation and Home Environment among Standard Eight Pupils

ERIC Educational Resources Information Center

Muola, J. M.

2010-01-01

The objective of this study was to investigate the relationship between academic achievement motivation and home environment among standard eight pupils. The study was carried out on 235 standard eight Kenyan pupils from six urban and rural primary schools randomly selected from Machakos district. Their age ranged between 13 and 17 years. Two…

The Mortality Risk of Conventional Antipsychotics in Elderly Patients: A Systematic Review and Meta-analysis of Randomized Placebo-Controlled Trials.

PubMed

Hulshof, Tessa A; Zuidema, Sytse U; Ostelo, Raymond W J G; Luijendijk, Hendrika J

2015-10-01

Numerous observational studies have reported an increased risk of mortality for conventional antipsychotics in elderly patients, and for haloperidol in particular. Subsequently, health authorities have warned against use of conventional antipsychotics in dementia. Experimental evidence is lacking. To assess the mortality risk of conventional antipsychotics in elderly patients with a meta-analysis of trials. Original studies were identified in electronic databases, online trial registers, and hand-searched references of published reviews. Two investigators found 28 potentially eligible studies, and they selected 17 randomized placebo-controlled trials in elderly patients with dementia, delirium, or a high risk of delirium. Two investigators independently abstracted trial characteristics and deaths, and 3 investigators assessed the risk of bias. Deaths were pooled with RevMan to obtain risk differences and risk ratios. Data of 17 trials with a total of 2387 participants were available. Thirty-two deaths occurred. The pooled risk difference of 0.1% was not statistically significant (95% confidence interval (CI) -1.0%-1.2%). The risk ratio was 1.07 (95% CI 0.54-2.13). Eleven of 17 trials tested haloperidol (n = 1799). The risk difference was 0.4% (95% CI -0.9%-1.6%), the risk ratio was 1.25 (95% CI 0.59-2.65). This meta-analysis of placebo-controlled randomized trials does not show that conventional antipsychotics in general or haloperidol in particular increase the risk of mortality in elderly patients. It questions the observational findings and the warning based on these findings. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

CONCEPTUAL AND METHODOLOGICAL ISSUES IN DESIGNING A RANDOMIZED CONTROLLED TREATMENT TRIAL FOR GERIATRIC BIPOLAR DISORDER: GERI-BD

PubMed Central

Young, Robert C.; Schulberg, Herbert C.; Gildengers, Ariel G.; Sajatovic, Martha; Mulsant, Benoit H.; Gyulai, Laszlo; Beyer, John; Marangell, Lauren; Kunik, Mark; Have, Thomas Ten; Bruce, Martha L.; Gur, Ruben; Marino, Patricia; Evans, Jovier D.; Reynolds, Charles F.; Alexopoulos, George S.

2010-01-01

Aim This report considers the conceptual and methodological concerns confronting clinical investigators seeking to generate knowledge regarding the tolerability and benefits of pharmacotherapy in geriatric bipolar (BP) patients. Method There is continuing need for evidence-based guidelines derived from randomized controlled trials that will enhance drug treatment of geriatric BP patients. We, therefore, present the complex conceptual and methodological choices encountered in designing a multi-site clinical trial and the decisions reached by the investigators with the intention that study findings are pertinent to, and can facilitate, routine treatment decisions. Results Guided by a literature review and input from peers, the tolerability and anti-manic effect of lithium and valproate were judged to be the key mood stabilizers to investigate with regard to treating BP I manic, mixed and hypomanic states. The patient selection criteria are intended to generate a sample that experiences common treatment needs but which also represents the variety of older patients seen in university-based clinical settings. The clinical protocol guides titratation of lithium and valproate to target serum concentrations, with lower levels allowed when necessitated by limited tolerability. The protocol emphasizes initial monotherapy. However, augmentation with risperidone is permitted after three weeks when indicated by operational criteria. Conclusions A randomized controlled trial that both investigates commonly prescribed mood stabilizers and maximizes patient participation can meaningfully address high priority clinical concerns directly relevant to the routine pharmacologic treatment of geriatric BP patients. PMID:20148867

Early skin-to-skin contact after cesarean section: A randomized clinical pilot study

PubMed Central

Kollmann, Martina; Aldrian, Lisa; Scheuchenegger, Anna; Mautner, Eva; Herzog, Sereina A.; Urlesberger, Berndt; Raggam, Reinhard B.; Lang, Uwe; Obermayer-Pietsch, Barbara; Klaritsch, Philipp

2017-01-01

Objective Early bonding by skin-to-skin contact (SSC) has been demonstrated to be beneficial for mothers and newborns following vaginal delivery. The aim of this study was to investigate the impact of intraoperative bonding (early SSC) after cesarean section on neonatal adaptation, maternal pain and stress response. Study design This prospective, randomized-controlled pilot study was performed at a single academic tertiary hospital (Department of Obstetrics and Gynecology, Medical University of Graz, Austria) between September 2013 and January 2014. Women were randomly assigned to intraoperative (“early”) SCC (n = 17) versus postoperative (“late”) SCC (n = 18). Main variables investigated were neonatal transition (Apgar score, arterial oxygen saturation, heart rate and temperature), maternal pain perception and both maternal and neonatal stress response by measuring the stress biomarkers salivary free cortisol and salivary alpha amylase. Results There was no evidence for differences in parameters reflecting neonatal transition or stress response between the ‘Early SSC Group’ and the ‘Late SSC Group’. Maternal salivary cortisol and alpha-amylase levels as well as maternal wellbeing and pain did not differ between the groups. However, the rise of maternal salivary alpha-amylase directly after delivery was higher in the ‘Early SSC Group’ compared to the ‘Late SSC Group’ (p = 0.004). Conclusions This study did not reveal significant risks for the newborn in terms of neonatal transition when early SSC is applied in the operating room. Maternal condition and stress marker levels did not differ either, although the rise of maternal salivary alpha-amylase directly after delivery was higher in the ‘Early SSC Group’ compared to the ‘Late SSC Group’, which may indicate a stressor sign due to intensive activation of the sympathetic-adreno-medullary-system. This needs to be further evaluated in a larger prospective randomized trial. Trial registration ClinicalTrials.gov NCT01894880 PMID:28231274

A Study on Young Turkish Students' Living Thing Conception

ERIC Educational Resources Information Center

Özgur, Sami

2018-01-01

The aim of this study is to find out young Turkish students' opinions about living thing concept in detail and to investigate the criteria used by the students to define this concept. The study sample consisted of randomly selected 140 students studying at the 3rd, 4th and 5th grades in four different primary and middle schools located in the…

Generalized SAMPLE SIZE Determination Formulas for Investigating Contextual Effects by a Three-Level Random Intercept Model.

PubMed

Usami, Satoshi

2017-03-01

Behavioral and psychological researchers have shown strong interests in investigating contextual effects (i.e., the influences of combinations of individual- and group-level predictors on individual-level outcomes). The present research provides generalized formulas for determining the sample size needed in investigating contextual effects according to the desired level of statistical power as well as width of confidence interval. These formulas are derived within a three-level random intercept model that includes one predictor/contextual variable at each level to simultaneously cover various kinds of contextual effects that researchers can show interest. The relative influences of indices included in the formulas on the standard errors of contextual effects estimates are investigated with the aim of further simplifying sample size determination procedures. In addition, simulation studies are performed to investigate finite sample behavior of calculated statistical power, showing that estimated sample sizes based on derived formulas can be both positively and negatively biased due to complex effects of unreliability of contextual variables, multicollinearity, and violation of assumption regarding the known variances. Thus, it is advisable to compare estimated sample sizes under various specifications of indices and to evaluate its potential bias, as illustrated in the example.

Improved sampling and analysis of images in corneal confocal microscopy.

PubMed

Schaldemose, E L; Fontain, F I; Karlsson, P; Nyengaard, J R

2017-10-01

Corneal confocal microscopy (CCM) is a noninvasive clinical method to analyse and quantify corneal nerve fibres in vivo. Although the CCM technique is in constant progress, there are methodological limitations in terms of sampling of images and objectivity of the nerve quantification. The aim of this study was to present a randomized sampling method of the CCM images and to develop an adjusted area-dependent image analysis. Furthermore, a manual nerve fibre analysis method was compared to a fully automated method. 23 idiopathic small-fibre neuropathy patients were investigated using CCM. Corneal nerve fibre length density (CNFL) and corneal nerve fibre branch density (CNBD) were determined in both a manual and automatic manner. Differences in CNFL and CNBD between (1) the randomized and the most common sampling method, (2) the adjusted and the unadjusted area and (3) the manual and automated quantification method were investigated. The CNFL values were significantly lower when using the randomized sampling method compared to the most common method (p = 0.01). There was not a statistical significant difference in the CNBD values between the randomized and the most common sampling method (p = 0.85). CNFL and CNBD values were increased when using the adjusted area compared to the standard area. Additionally, the study found a significant increase in the CNFL and CNBD values when using the manual method compared to the automatic method (p ≤ 0.001). The study demonstrated a significant difference in the CNFL values between the randomized and common sampling method indicating the importance of clear guidelines for the image sampling. The increase in CNFL and CNBD values when using the adjusted cornea area is not surprising. The observed increases in both CNFL and CNBD values when using the manual method of nerve quantification compared to the automatic method are consistent with earlier findings. This study underlines the importance of improving the analysis of the CCM images in order to obtain more objective corneal nerve fibre measurements. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Effect of joint mobilization techniques for primary total knee arthroplasty: Study protocol for a randomized controlled trial.

PubMed

Xu, Jiao; Zhang, Juan; Wang, Xue-Qiang; Wang, Xuan-Lin; Wu, Ya; Chen, Chan-Cheng; Zhang, Han-Yu; Zhang, Zhi-Wan; Fan, Kai-Yi; Zhu, Qiang; Deng, Zhi-Wei

2017-12-01

Total knee arthroplasty (TKA) has become the most preferred procedure by patients for the relief of pain caused by knee osteoarthritis. TKA patients aim a speedy recovery after the surgery. Joint mobilization techniques for rehabilitation have been widely used to relieve pain and improve joint mobility. However, relevant randomized controlled trials showing the curative effect of these techniques remain lacking to date. Accordingly, this study aims to investigate whether joint mobilization techniques are valid for primary TKA. We will manage a single-blind, prospective, randomized, controlled trial of 120 patients with unilateral TKA. Patients will be randomized into an intervention group, a physical modality therapy group, and a usual care group. The intervention group will undergo joint mobilization manipulation treatment once a day and regular training twice a day for a month. The physical modality therapy group will undergo physical therapy once a day and regular training twice a day for a month. The usual care group will perform regular training twice a day for a month. Primary outcome measures will be based on the visual analog scale, the knee joint Hospital for Special Surgery score, range of motion, surrounded degree, and adverse effect. Secondary indicators will include manual muscle testing, 36-Item Short Form Health Survey, Berg Balance Scale function evaluation, Pittsburgh Sleep Quality Index, proprioception, and muscle morphology. We will direct intention-to-treat analysis if a subject withdraws from the trial. The important features of this trial for joint mobilization techniques in primary TKA are randomization procedures, single-blind, large sample size, and standardized protocol. This study aims to investigate whether joint mobilization techniques are effective for early TKA patients. The result of this study may serve as a guide for TKA patients, medical personnel, and healthcare decision makers. It has been registered at http://www.chictr.org.cn/showproj.aspx?proj=15262 (Identifier:ChiCTR-IOR-16009192), Registered 11 September 2016. We also could provide the correct URL of the online registry in the WHO Trial Registration. http://apps.who.int/trialsearch/Trial2.aspx?TrialID=ChiCTR-IOR-16009192.

Random vibration analysis of train-bridge under track irregularities and traveling seismic waves using train-slab track-bridge interaction model

NASA Astrophysics Data System (ADS)

Zeng, Zhi-Ping; Zhao, Yan-Gang; Xu, Wen-Tao; Yu, Zhi-Wu; Chen, Ling-Kun; Lou, Ping

2015-04-01

The frequent use of bridges in high-speed railway lines greatly increases the probability that trains are running on bridges when earthquakes occur. This paper investigates the random vibrations of a high-speed train traversing a slab track on a continuous girder bridge subjected to track irregularities and traveling seismic waves by the pseudo-excitation method (PEM). To derive the equations of motion of the train-slab track-bridge interaction system, the multibody dynamics and finite element method models are used for the train and the track and bridge, respectively. By assuming track irregularities to be fully coherent random excitations with time lags between different wheels and seismic accelerations to be uniformly modulated, non-stationary random excitations with time lags between different foundations, the random load vectors of the equations of motion are transformed into a series of deterministic pseudo-excitations based on PEM and the wheel-rail contact relationship. A computer code is developed to obtain the time-dependent random responses of the entire system. As a case study, the random vibration characteristics of an ICE-3 high-speed train traversing a seven-span continuous girder bridge simultaneously excited by track irregularities and traveling seismic waves are analyzed. The influence of train speed and seismic wave propagation velocity on the random vibration characteristics of the bridge and train are discussed.

Investigation of microsatellite instability in Turkish breast cancer patients.

PubMed

Demokan, Semra; Muslumanoglu, Mahmut; Yazici, H; Igci, Abdullah; Dalay, Nejat

2002-01-01

Multiple somatic and inherited genetic changes that lead to loss of growth control may contribute to the development of breast cancer. Microsatellites are tandem repeats of simple sequences that occur abundantly and at random throughout most eucaryotic genomes. Microsatellite instability (MI), characterized by the presence of random contractions or expansions in the length of simple sequence repeats or microsatellites, is observed in a variety of tumors. The aim of this study was to compare tumor DNA fingerprints with constitutional DNA fingerprints to investigate changes specific to breast cancer and evaluate its correlation with clinical characteristics. Tumor and normal tissue samples of 38 patients with breast cancer were investigated by comparing PCR-amplified microsatellite sequences D2S443 and D21S1436. Microsatellite instability at D21S1436 and D2S443 was found in 5 (13%) and 7 (18%) patients, respectively. Two patients displayed instability at both marker loci. No association was found between MI and age, family history, lymph node involvement and other clinical parameters.

Safety and Efficacy of Nanocurcumin as Add-On Therapy to Riluzole in Patients With Amyotrophic Lateral Sclerosis: A Pilot Randomized Clinical Trial.

PubMed

Ahmadi, Mona; Agah, Elmira; Nafissi, Shahriar; Jaafari, Mahmoud Reza; Harirchian, Mohammad Hossein; Sarraf, Payam; Faghihi-Kashani, Sara; Hosseini, Seyed Jalal; Ghoreishi, Abdolreza; Aghamollaii, Vajiheh; Hosseini, Mostafa; Tafakhori, Abbas

2018-04-01

The objective of present study was to assess the safety and efficacy of nanocurcumin as an anti-inflammatory and antioxidant agent in adults with amyotrophic lateral sclerosis (ALS). We conducted a 12-month, double-blind, randomized, placebo-controlled trial at a neurological referral center in Iran. Eligible patients with a definite or probable ALS diagnosis were randomly assigned to receive either nanocurcumin (80 mg daily) or placebo in a 1:1 ratio. A computerized random number generator was used to prepare the randomization list. All patients and research investigators were blinded to treatment allocation. The primary outcome was survival, and event was defined to be death or mechanical ventilation dependency. Analysis was by intention-to-treat and included all patients who received at least one dose of study drug. A total of 54 patients were randomized to receive either nanocurcumin (n = 27) or placebo (n = 27). After 12 months, events occurred in 1 patient (3.7%) in the nanocurcumin group and in 6 patients (22.2%) in the placebo group. Kaplan-Meier analysis revealed a significant difference between the study groups regarding their survival curves (p = 0.036). No significant between-group differences were observed for any other outcome measures. No serious adverse events or treatment-related deaths were detected. No patients withdrew as a result of drug adverse events. The results suggest that nanocurcumin is safe and might improve the probability of survival as an add-on treatment in patients with ALS, especially in those with existing bulbar symptoms. Future studies with larger sample sizes and of longer duration are needed to confirm these findings.

Cryopreserved human amniotic membrane injection for plantar fasciitis: a randomized, controlled, double-blind pilot study.

PubMed

Hanselman, Andrew E; Tidwell, John E; Santrock, Robert D

2015-02-01

Treatment options for plantar fasciitis have resulted in varied patient outcomes. The aim of this study was to compare a novel treatment, cryopreserved human amniotic membrane (c-hAM), to a traditional treatment, corticosteroid. Our hypothesis was that c-hAM would be safe and comparable to corticosteroids for plantar fasciitis in regard to patient outcomes. A randomized, controlled, double-blind, single-center pilot study was completed. Patients were randomized into one of 2 treatment groups: c-hAM or corticosteroid. Patients received an injection at their initial baseline visit with an option for a second injection at their first 6-week follow-up. Total follow-up was obtained for 12 weeks after the most recent injection. The primary outcome measurement was the Foot Health Status Questionnaire (FHSQ). The secondary outcome measurements were the Visual Analog Scale (VAS) and verbally reported percentage improvement. Data were analyzed between groups for the 2 different cohorts (1 injection versus 2 injections). Twenty-three patients had complete follow-up. Fourteen were randomized to receive corticosteroid and 9 were randomized to receive c-hAM. Three patients in each group received second injections. With the numbers available, the majority of outcome measurements showed no statistical difference between groups. The corticosteroid did, however, have greater FHSQ shoe fit improvement (P = .0244) at 6 weeks, FHSQ general health improvement (P = .0132) at 6 weeks, and verbally reported improvement (P = .041) at 12 weeks in the one-injection cohort. Cryopreserved hAM had greater FHSQ foot pain improvement (P = .0113) at 18 weeks in the 2-injection cohort. Cryopreserved hAM injection may be safe and comparable to corticosteroid injection for treatment of plantar fasciitis. This is a pilot study and requires further investigation. Level I, prospective randomized trial. © The Author(s) 2014.

Intention-to-Treat Analysis in Partially Nested Randomized Controlled Trials with Real-World Complexity

ERIC Educational Resources Information Center

Schweig, Jonathan David; Pane, John F.

2016-01-01

Demands for scientific knowledge of what works in educational policy and practice has driven interest in quantitative investigations of educational outcomes, and randomized controlled trials (RCTs) have proliferated under these conditions. In educational settings, even when individuals are randomized, both experimental and control students are…

Cognitive-Behavioral Treatment of Panic Disorder in Adolescence

ERIC Educational Resources Information Center

Pincus, Donna B.; May, Jill Ehrenreich; Whitton, Sarah W.; Mattis, Sara G.; Barlow, David H.

2010-01-01

This investigation represents the first randomized controlled trial to evaluate the feasibility and efficacy of Panic Control Treatment for Adolescents (PCT-A). Thirteen adolescents, ages 14 to 17, were randomized to 11 weekly sessions of PCT-A treatment, whereas 13 were randomized to a self-monitoring control group. Results indicate that…

78 FR 25767 - Certain Static Random Access Memories and Products Containing Same; Commission Determination To...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-02

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-792] Certain Static Random Access Memories and Products Containing Same; Commission Determination To Review in Part a Final Initial... States after importation of certain static random access memories and products containing the same by...

Designing and conducting a randomized trial for pandemic critical illness: the 2009 H1N1 influenza pandemic.

PubMed

Annane, Djillali; Antona, Marion; Lehmann, Blandine; Kedzia, Cecile; Chevret, Sylvie

2012-01-01

To analyze the hurdles in implementing a randomized trial of corticosteroids for severe 2009 H1N1 influenza infections. This was an investigator-led, multicenter, randomized, placebo-controlled, double-blind trial of corticosteroids in ICU patients with 2009 H1N1 influenza pneumonia requiring mechanical ventilation. The feasibility of and hurdles in designing and initiating a phase III trial in a short-lived pandemic crisis were analyzed. The regulatory agency and ethics committee approved the study's scientific, financial, and ethical aspects within 4 weeks. Hydrocortisone and placebo were prepared centrally and shipped to participating hospitals within 6 weeks. The inclusion period started on November 9, 2009. From August 1, 2009 to March 8, 2010, only 205/224 ICU patients with H1N1 infections required mechanical ventilation. The peak of the wave was missed by 2-3 weeks and only 26 patients were randomized. The two main reasons for non-inclusion were patients' admission before the beginning of the trial and ICU personnel overwhelmed by clinical duties. Parallel rather than sequential regulatory and ethics approval, and preparation and masking of study drugs by local pharmacists would have allowed the study to start 1 month earlier and before the peak of the "flu" wave. A dedicated research team in each participating center would have increased the ratio of screened to randomized patients. This report highlights the main hurdles in implementing a randomized trial for a pandemic critical illness and proposes solutions for future trials.

School Counselors and Child Abuse Reporting: A National Survey

ERIC Educational Resources Information Center

Bryant, Jill K.

2009-01-01

A study was done to investigate school counselors' child abuse reporting behaviors and perceptions regarding the child abuse reporting process. Participants were randomly selected from the American School Counselor Association membership database with 193 school counselors returning questionnaires. Overall, school counselors indicated that they…

Predicting Employment Outcomes of Consumers of State-Operated Comprehensive Rehabilitation Centers

ERIC Educational Resources Information Center

Beach, David Thomas

2009-01-01

This study used records from a state-operated comprehensive rehabilitation center to investigate possible predictive factors related to completing comprehensive rehabilitation center programs and successful vocational rehabilitation (VR) case closure. An analysis of demographic data of randomly selected comprehensive rehabilitation center…

Detecting Latent Heterogeneity

ERIC Educational Resources Information Center

Pearl, Judea

2017-01-01

We address the task of determining, from statistical averages alone, whether a population under study consists of several subpopulations, unknown to the investigator, each responding to a given treatment markedly differently. We show that such determination is feasible in three cases: (1) randomized trials with binary treatments, (2) models where…

Predictors of Cyberloafing among Preservice Information Technology Teachers

ERIC Educational Resources Information Center

Dursun, Ozcan Ozgur; Donmez, Onur; Akbulut, Yavuz

2018-01-01

The current mixed-method study investigated the extent of involvement in cyberloafing within classroom settings among preservice information technology teachers. Thirteen state universities were picked randomly from hierarchical clusters, which were determined according to the national university rankings. Then, a recent five-factor cyberloafing…

Metacognitive Listening Strategies Used by Saudi EFL Medical Students

ERIC Educational Resources Information Center

Alhaison, Eid

2017-01-01

The present study investigated the metacognitive listening strategies among Saudi EFL medical students. The participants were 104 males and females, randomly selected to fill in the Metacognitive Awareness Listening Questionnaire (MALQ), developed and validated Vandergrift Goh, Mareschal, and Tafaghodtari (2006). The results revealed that…

School Psychologists' Continuing Professional Development Preferences and Practices

ERIC Educational Resources Information Center

Armistead, Leigh D.; Castillo, Jose M.; Curtis, Michael J.; Chappel, Ashley; Cunningham, Jennifer

2013-01-01

This study investigated school psychologists' continuing professional development (CPD) activities, topics, needs, motivations, financial expenditures, and opinions, as well as relationships between select demographic characteristics and certain CPD practices and preferences. A survey was mailed to 1,000 randomly selected Regular Members of…

Identification of Teaching Behaviors Which Predict Success for Mainstreamed Students.

ERIC Educational Resources Information Center

Larrivee, Barbara; Algina, James

The final phase of a study investigating effective teaching behaviors for mainstreamed students involved 118 elementary teachers. Teachers provided information on mainstreamed students and a sample of students was randomly selected to represent classification categories (learning disabilities, behavior disorders, speech impairments, and hearing…

Asymptotic analysis of the density of states in random matrix models associated with a slowly decaying weight

NASA Astrophysics Data System (ADS)

Kuijlaars, A. B. J.

2001-08-01

The asymptotic behavior of polynomials that are orthogonal with respect to a slowly decaying weight is very different from the asymptotic behavior of polynomials that are orthogonal with respect to a Freud-type weight. While the latter has been extensively studied, much less is known about the former. Following an earlier investigation into the zero behavior, we study here the asymptotics of the density of states in a unitary ensemble of random matrices with a slowly decaying weight. This measure is also naturally connected with the orthogonal polynomials. It is shown that, after suitable rescaling, the weak limit is the same as the weak limit of the rescaled zeros.

Randomized double-blind placebo-controlled multicenter evaluation of efficacy and dose finding of midodrine hydrochloride in women with mild to moderate stress urinary incontinence: a phase II study.

PubMed

Weil, E H; Eerdmans, P H; Dijkman, G A; Tamussino, K; Feyereisl, J; Vierhout, M E; Schmidbauer, C; Egarter, C; Kölle, D; Plasman, J E; Heidler, H; Abbühl, B E; Wein, W

1998-01-01

Midodrine is a potent and selective alpha1-receptor agonist and its potential to increase urethral closure pressure could be useful in the treatment of female stress incontinence. The aim of this randomized double-blind placebo-controlled multicenter study was to evaluate the efficacy and safety of midodrine for the treatment of stress urinary incontinence. The primary criterion of efficacy was the maximum urethral closure pressure at rest. Voiding diaries, symptom and incontinence questionnaires and patient/investigator global assessment were also used to evaluate its efficacy. After 4 weeks of treatment no significant changes in MUCP were found. The global assessment by the patient and investigator did indicate that patients on active treatment had a more positive assessment than the placebo group. In conclusion, midodrine did not cause significant improvements in urodynamic parameters, but there were subjective improvements in some of the patients in the treated groups. Furthermore midodrine was well tolerated.

An Investigation of Effectiveness of Conceptual Change Text-oriented Instruction on Students' Understanding of Solution Concepts

NASA Astrophysics Data System (ADS)

Pinarbaşi; , Tacettin; Canpolat, Nurtaç; Bayrakçeken, Samih; Geban, Ömer

2006-12-01

This study investigated the effect of conceptual change text-oriented instruction over traditional instruction on students' understanding of solution concepts (e.g., dissolving, solubility, factors affecting solubility, concentrations of solutions, types of solutions, physical properties of solutions) and their attitudes towards chemistry. The sample of this study consisted of 87 undergraduate students from two classes enrolled in an introductory chemistry course. One of the classes was assigned randomly to the control group, and the other class were assigned randomly to the experimental group. During teaching the topic of solution concepts in the chemistry curriculum, a conceptual change text-oriented instruction was applied in the experimental group whereas traditional instruction was followed in the control group. The results showed that the students in the experimental group performed better with respect to solution concepts. In addition, it has been found that there was no significant difference between the attitudes of students in the experimental and control groups towards chemistry.

OSI Network-layer Abstraction: Analysis of Simulation Dynamics and Performance Indicators

NASA Astrophysics Data System (ADS)

Lawniczak, Anna T.; Gerisch, Alf; Di Stefano, Bruno

2005-06-01

The Open Systems Interconnection (OSI) reference model provides a conceptual framework for communication among computers in a data communication network. The Network Layer of this model is responsible for the routing and forwarding of packets of data. We investigate the OSI Network Layer and develop an abstraction suitable for the study of various network performance indicators, e.g. throughput, average packet delay, average packet speed, average packet path-length, etc. We investigate how the network dynamics and the network performance indicators are affected by various routing algorithms and by the addition of randomly generated links into a regular network connection topology of fixed size. We observe that the network dynamics is not simply the sum of effects resulting from adding individual links to the connection topology but rather is governed nonlinearly by the complex interactions caused by the existence of all randomly added and already existing links in the network. Data for our study was gathered using Netzwerk-1, a C++ simulation tool that we developed for our abstraction.

Can we reduce eating disorder risk factors in female college athletes? A randomized exploratory investigation of two peer-led interventions

PubMed Central

Becker, Carolyn Black; McDaniel, Leda; Bull, Stephanie; Powell, Marc; McIntyre, Kevin

2011-01-01

Female athletes are at least as at risk as other women for eating disorders (EDs) and at risk for the female athlete triad (i.e., inadequate energy availability, menstrual disorders, and osteoporosis). This study investigated whether two evidence-based programs appear promising for future study if modified to address the unique needs of female athletes. Athletes were randomly assigned to athlete-modified dissonance prevention or healthy weight intervention (AM-HWI). ED risk factors were assessed pre/post-treatment, and 6-week and 1-year follow-up. Results (analyzed sample N = 157) indicated that both interventions reduced thin-ideal internalization, dietary restraint, bulimic pathology, shape and weight concern, and negative affect at 6 weeks, and bulimic pathology, shape concern, and negative affect at 1 year. Unexpectedly we observed an increase in students spontaneously seeking medical consultation for the triad. Qualitative results suggested that AM-HWI may be more preferred by athletes. PMID:22019502

The Clinical Effects of Aromatherapy Massage on Reducing Pain for the Cancer Patients: Meta-Analysis of Randomized Controlled Trials.

PubMed

Chen, Ting-Hao; Tung, Tao-Hsin; Chen, Pei-Shih; Wang, Shu-Hui; Chao, Chuang-Min; Hsiung, Nan-Hsing; Chi, Ching-Chi

2016-01-01

Purpose. Aromatherapy massage is an alternative treatment in reducing the pain of the cancer patients. This study was to investigate whether aromatherapy massage could improve the pain of the cancer patients. Methods. We searched PubMed and Cochrane Library for relevant randomized controlled trials without language limitations between 1 January 1990 and 31 July 2015 with a priori defined inclusion and exclusion criteria. The search terms included aromatherapy, essential oil, pain, ache, cancer, tumor, and carcinoma. There were 7 studies which met the selection criteria and 3 studies were eventually included among 63 eligible publications. Results. This meta-analysis included three randomized controlled trials with a total of 278 participants (135 participants in the massage with essential oil group and 143 participants in the control (usual care) group). Compared with the control group, the massage with essential oil group had nonsignificant effect on reducing the pain (standardized mean difference = 0.01; 95% CI [-0.23,0.24]). Conclusion. Aromatherapy massage does not appear to reduce pain of the cancer patients. Further rigorous studies should be conducted with more objective measures.

Universal statistics of vortex tangles in three-dimensional random waves

NASA Astrophysics Data System (ADS)

Taylor, Alexander J.

2018-02-01

The tangled nodal lines (wave vortices) in random, three-dimensional wavefields are studied as an exemplar of a fractal loop soup. Their statistics are a three-dimensional counterpart to the characteristic random behaviour of nodal domains in quantum chaos, but in three dimensions the filaments can wind around one another to give distinctly different large scale behaviours. By tracing numerically the structure of the vortices, their conformations are shown to follow recent analytical predictions for random vortex tangles with periodic boundaries, where the local disorder of the model ‘averages out’ to produce large scale power law scaling relations whose universality classes do not depend on the local physics. These results explain previous numerical measurements in terms of an explicit effect of the periodic boundaries, where the statistics of the vortices are strongly affected by the large scale connectedness of the system even at arbitrarily high energies. The statistics are investigated primarily for static (monochromatic) wavefields, but the analytical results are further shown to directly describe the reconnection statistics of vortices evolving in certain dynamic systems, or occurring during random perturbations of the static configuration.

Bicomponent Block Copolymers Derived from One or More Random Copolymers as an Alternative Route to Controllable Phase Behavior

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

Ashraf, Arman R.; Ryan, Justin J.; Satkowski, Michael M.

Block copolymers have been extensively studied due to their ability to spontaneously self-organize into a wide variety of morphologies that are valuable in energy-, medical- and conservation-related (nano)technologies. While the phase behavior of bicomponent diblock and triblock copolymers is conventionally governed by temperature and individual block masses, we demonstrate that their phase behavior can alternatively be controlled through the use of blocks with random monomer sequencing. Block random copolymers (BRCs), i.e., diblock copolymers wherein one or both blocks is a random copolymer comprised of A and B repeat units, have been synthesized, and their phase behavior, expressed in terms ofmore » the order-disorder transition (ODT), has been investigated. Our results establish that, depending on the block composition contrast and molecular weight, BRCs can microphase-separate. We also report that the predicted ODT can be generated at relatively constant molecular weight and temperature with these new soft materials. This sequence-controlled synthetic strategy is extended to thermoplastic elastomeric triblock copolymers differing in chemistry and possessing a random-copolymer midblock.« less

Investigating Organizational Alienation Behavior in Terms of Some Variables

ERIC Educational Resources Information Center

Dagli, Abidin; Averbek, Emel

2017-01-01

The aim of this study is to detect the perceptions of public primary school teachers regarding organizational alienation behaviors in terms of some variables (gender, marital status and seniority). Survey model was used in this study. The research sample consists of randomly selected 346 teachers from 40 schools in the central district of Mardin,…

A Study of the Relationship between Demographic Factors and Elementary School Teacher Burnout: The Iranian Case

ERIC Educational Resources Information Center

Mazidi, Mohammad; Khoshbakht, Friba; Mahboobe, Alborzi

2017-01-01

The aim of the present study was to investigate the relationship between certain demographic factors and elementary school teachers' burnout. The sample consisted of 144 elementary school teachers (98 male and 76 women) selected through cluster random sampling. Data were collected by: (1) Personal Information Form developed by the researchers, and…

The Effects of Hypertext Gloss on Comprehension and Vocabulary Retention under Incidental and Intentional Learning Conditions

ERIC Educational Resources Information Center

Zandieh, Zeinab; Jafarigohar, Manoochehr

2012-01-01

The present study investigated comprehension, immediate and delayed vocabulary retention under incidental and intentional learning conditions via computer mediated hypertext gloss. One hundred and eighty four (N = 184) intermediate students of English as a foreign language at an English school participated in the study. They were randomly assigned…

Effect of Polya Problem-Solving Model on Senior Secondary School Students' Performance in Current Electricity

ERIC Educational Resources Information Center

Olaniyan, Ademola Olatide; Omosewo, Esther O.; Nwankwo, Levi I.

2015-01-01

This study was designed to investigate the Effect of Polya Problem-Solving Model on Senior School Students' Performance in Current Electricity. It was a quasi experimental study of non- randomized, non equivalent pre-test post-test control group design. Three research questions were answered and corresponding three research hypotheses were tested…

Using Advance Organizers to Enhance Pupils' Achievement in Learning Poetry in English Language

ERIC Educational Resources Information Center

Muiruri, Mary; Wambugu, Patriciah; Wamukuru, Kuria

2016-01-01

The study was a quasi-experimental that investigated the effects of Advance Organizers (AO) on achievement in poetry. Target population was class seven pupils of Nakuru North Sub-county primary schools in Kenya. 160 pupils were involved in the study. Four sampled schools were randomly assigned to control and experimental groups in Solomon Four…

Severity of Organized Item Theft in Computerized Adaptive Testing: An Empirical Study. Research Report. ETS RR-06-22

ERIC Educational Resources Information Center

Yi, Qing; Zhang, Jinming; Chang, Hua-Hua

2006-01-01

Chang and Zhang (2002, 2003) proposed several baseline criteria for assessing the severity of possible test security violations for computerized tests with high-stakes outcomes. However, these criteria were obtained from theoretical derivations that assumed uniformly randomized item selection. The current study investigated potential damage caused…

Impact of Sex Education in Kogi State, Nigeria

ERIC Educational Resources Information Center

Sule, H. A.; Akor, J. A.; Toluhi, O. J.; Suleiman, R. O.; Akpihi, L.; Ali, O. U.

2015-01-01

The focus of this study was to investigate the impact of family sex education in secondary schools on students in Kogi State, Nigeria. The descriptive survey design was used for the study. A total of 1,960 secondary school students were drawn by stratified random sampling from 40 schools within Kogi State, Nigeria. Three research questions were…

Implications of Therapist Effects for the Design and Analysis of Comparative Studies of Psychotherapies.

ERIC Educational Resources Information Center

Crits-Christoph, Paul; Mintz, Jim

1991-01-01

Presents reasons therapist should be included as random design factor in nested analysis of (co)variance (AN[C]OVA) design used in psychotherapy research. Reviews studies which indicate majority of investigators ignore issue of effects from incorrect specification of ANOVA design. Presents reanalysis of data from 10 psychotherapy outcome studies…

The Impact of Concept Mapping on EFL Learners' Critical Thinking Ability

ERIC Educational Resources Information Center

Khodadady, Ebrahim; Ghanizadeh, Afsaneh

2011-01-01

The present study investigated the influence of concept mapping as a post-reading strategy on EFL learners' critical thinking ability. The study utilized a pretest-posttest control and experimental group design. To do so, thirty six EFL learners at upper intermediate and advanced levels were randomly assigned to experimental (n=18) and control…

The Cloze Procedure: A Measure for Determining Readability Level for Vocational Junior College Students.

ERIC Educational Resources Information Center

Caffey, Musa B.

One hundred students enrolled in the welding and air-conditioning/refrigeration classes at Delgado Community College (Louisiana) were randomly selected to participate in a study to evaluate their effective reading comprehension level, to investigate the impact of a study skill "preview" method such as the SQ3R on their test-taking…

A Study of the Effects of Verbalization on Concept Formation in Mathematics.

ERIC Educational Resources Information Center

Albig, David L.

The purpose of the study was to investigate the hypothesis that requiring a student to verbalize a newly discovered mathematical concept interferes with his ability to use that concept. Five semi-programmed lessons (dealing with function machines, exponents, marker games, geometry, and One Pile Nim) were prepared and taught to a random selection…

Fit between Future Thinking and Future Orientation on Creative Imagination

ERIC Educational Resources Information Center

Chiu, Fa-Chung

2012-01-01

The purpose of the current study is to investigate the impact of future thinking, and the fit between future thinking and future orientation on creative thinking. In Study 1, 83 undergraduates were randomly assigned to three groups: 50-year future thinking, 5-year future thinking, and the present-day thinking. First, the priming tasks, in which…

The Effects of Different Pre-Writing Strategies on Iranian EFL Writing Achievement

ERIC Educational Resources Information Center

Mahnam, Lily; Nejadansari, Dariush

2012-01-01

This study aimed at investigating whether applying pre-writing strategies would affect the quality of L2 learners' compositions. Twenty three adult EFL students from Jahad-e-Daneshgahi English centre in Iran participated in this study. They were randomly assigned to control and experimental groups, including 11 and 12 participants in each. They…

Adult Adjustment of Individuals with Mild Disabilities One Year after Leaving School. Iowa State Follow-Up Study.

ERIC Educational Resources Information Center

Sitlington, Patricia L.; And Others

This study investigated the adult adjustment of a statewide random sample of 737 Iowa individuals with learning disabilities, 59 individuals labeled behaviorally disordered, and 142 individuals labeled mentally disabled, all graduates of special education resource teaching programs. Results are reported in terms of: (1) general status information,…

Social Intelligence of Principals and Its Relationship with Creative Behavior

ERIC Educational Resources Information Center

Kriemeen, Hani; Hajaia, Sulaiman

2017-01-01

The study aimed at investigating the level of the social intelligence among the male and female principals in Tafila Governorate from the teachers views and its relationship with creative behavior. The sample consisted of 190 male and female teachers chosen randomly. For achieving the goals of the study, the researchers developed two instruments,…

Intensive Quality Assurance of Therapist Adherence to Behavioral Interventions for Adolescent Substance Use Problems

ERIC Educational Resources Information Center

Holth, Per; Torsheim, Torbjorn; Sheidow, Ashli J.; Ogden, Terje; Henggeler, Scott W.

2011-01-01

This study was a cross-cultural replication of a study that investigated therapist adherence to behavioral interventions as a result of an intensive quality assurance system which was integrated into Multisystemic Therapy (MST). Thirty-three therapists and eight supervisors were block randomized to either an Intensive Quality Assurance or a…

USA Today: Accentuating the Positive: A Study of the Gannett Flagship Newspaper.

ERIC Educational Resources Information Center

Wright, William F.

To investigate whether "USA Today" emphasizes "good news" over "bad news," a study was conducted using 10 randomly selected adults in State College, Pennsylvania, over an 11-week period in 1985. Subjects were asked to rate 248 stories over 45 pages of main news columns in 10 issues on a scale ranging from 1 (very…

Effects of Multimedia Annotations on Incidental Vocabulary Learning and Reading Comprehension of Advanced Learners of English as a Foreign Language

ERIC Educational Resources Information Center

Akbulut, Yavuz

2007-01-01

The study investigates immediate and delayed effects of different hypermedia glosses on incidental vocabulary learning and reading comprehension of advanced foreign language learners. Sixty-nine freshman TEFL students studying at a Turkish university were randomly assigned to three types of annotations: (a) definitions of words, (b) definitions…

Mediating Role of Parental Influence in Children's Response to Television Commercials: An Exploratory Study.

ERIC Educational Resources Information Center

Prasad, V. Kanti; And Others

This study investigated, in a laboratory experimental framework, the relative influences of television commercials and parental counter-commercial advocacy on children's consumption choice behavior. Sixty-four 8- to 10-year-old boys were randomly assigned to one of three treatment groups: (1) no counter commercial advocacy (control group), (2)…

Effects of the Paraphrasing Strategy on Expository Reading Comprehension of Young Adults with Intellectual Disability

ERIC Educational Resources Information Center

Hua, Youjia; Woods-Groves, Suzanne; Ford, Jeremy W.; Nobles, Kelly A.

2014-01-01

The purpose of the study was to investigate the effectiveness of teaching a three-step paraphrasing strategy on expository reading comprehension of young adults with intellectual disability. Ten learners from a postsecondary education program for individuals with disability participated in the study. They were randomly assigned to the control and…

The Role of Preschool Teacher-Child Interactions in Academic Adjustment: An Intervention Study with Playing-2-Gether

ERIC Educational Resources Information Center

Van Craeyevelt, Sanne; Verschueren, Karine; Vancraeyveldt, Caroline; Wouters, Sofie; Colpin, Hilde

2017-01-01

Background: Social relationships can serve as important risk or protective factors for child development in general, and academic adjustment in particular. Aims: This study investigated the role of teacher-child interactions in academic adjustment among preschool boys at risk of externalizing behaviour, using a randomized controlled trial study…

The Evaluation of "English Textbook 2" Taught in Iranian High Schools from Teachers' Perspectives

ERIC Educational Resources Information Center

Ahour, Touran; Towhidiyan, Bayezid; Saeidi, Mahnaz

2014-01-01

The purpose of this study was to investigate the appropriateness of "English Textbook 2" for Iranian EFL second grade high school students from the teachers' perspectives. The participants of the study consisted of 25 English teachers (8 females and 17 males) randomly selected from different high schools in Boukan, Iran. The evaluation…

Mind Maps to Modify Lack of Attention among Saudi Kindergarten Children

ERIC Educational Resources Information Center

Daghistan, Bulquees Ismail Abdul Majid

2016-01-01

This research study aims at investigating the impact of Mind Maps on modifying the lack of attention in Arabic language class among Saudi Kindergarten children. To achieve the goals of this study the researcher used an experimental design with a random sample from AlRae'd Kindergarten's children in Riyadh -Saudi Arabia for the academic year…

MST with Conduct Disordered Youth in Sweden: Costs and Benefits after 2 Years

ERIC Educational Resources Information Center

Olsson, Tina M.

2010-01-01

Objectives: The purpose of this study was to investigate the costs and benefits associated with multisystemic therapy (MST) for conduct disordered youth, 2 years following intake. Methods: The study employed a secondary analysis of 156 youth enrolled in a randomized trial assessing the psychosocial and behavioral outcomes of MST. Results: MST cost…

Ethical Leadership and Teachers' Voice Behavior: The Mediating Roles of Ethical Culture and Psychological Safety

ERIC Educational Resources Information Center

Sagnak, Mesut

2017-01-01

The purpose of this study is to investigate the mediating effects of ethical culture and psychological safety on the relationship between ethical leadership and teachers' voice behavior. The sample consists of 342 teachers randomly selected from 25 primary and secondary schools. Four different instruments are used in this study. The scales have…

Evaluation of the Physical Education and Sports Curriculum in Turkish Schools

ERIC Educational Resources Information Center

Okmen, Ahmet Sadan

2017-01-01

This study assesses the vocational education courses given in schools of physical education and sport at Turkish universities and their use in the life of professionals. This study investigates 55 male and 25 female participants, aged 24 to 49, randomly selected from among the physical education and sport teachers in government and private schools…

Readers, Players, and Watchers: EFL Students' Vocabulary Acquisition through Digital Video Games

ERIC Educational Resources Information Center

Ebrahimzadeh, Mohsen

2017-01-01

The present study investigated vocabulary acquisition through a commercial digital video game compared to a traditional pencil-and-paper treatment. Chosen through cluster sampling, 241 male high school students (age 12-18) participated in the study. They were randomly assigned to one of the following groups. The first group, called Readers,…

Can Personalized Nudges Improve Learning in Hybrid Classes? Experimental Evidence from an Introductory Undergraduate Course

ERIC Educational Resources Information Center

O'Connell, Stephen D.; Lang, Guido

2018-01-01

A field experiment was conducted to investigate whether personalized e-mail reminders can improve study consistency and learning outcomes in an introductory-level undergraduate course. By randomly assigning whether nearly 300 students would receive occasional e-mail messages encouraging out-of-class study, we find that these reminders increased…

The Relationship between Emotional Intelligence and Problem Solving Skills in Prospective Teachers

ERIC Educational Resources Information Center

Deniz, Sabahattin

2013-01-01

This study aims to investigate the relationship between emotional intelligence and problem solving. The sample set of the research was taken from the Faculty of Education of Mugla University by the random sampling method. The participants were 386 students--prospective teachers--(224 females; 182 males) who took part in the study voluntarily.…

Towards Motivation-Based Adaptation of Difficulty in E-Learning Programs

ERIC Educational Resources Information Center

Endler, Anke; Rey, Gunter Daniel; Butz, Martin V.

2012-01-01

The objective of this study was to investigate if an e-learning environment may use measurements of the user's current motivation to adapt the level of task difficulty for more effective learning. In the reported study, motivation-based adaptation was applied randomly to collect a wide range of data for different adaptations in a variety of…

Stepped-Care, Community Clinic Interventions to Promote Mammography Use among Low-Income Rural African American Women

ERIC Educational Resources Information Center

West, Delia Smith; Greene, Paul; Pulley, LeaVonne; Kratt, Polly; Gore, Stacy; Weiss, Heidi; Siegfried, Nicole

2004-01-01

Few studies have investigated community clinic-based interventions to promote mammography screening among rural African American women. This study randomized older low-income rural African American women who had not participated in screening in the previous 2 years to a theory-based, personalized letter or usual care; no group differences in…

A Statistical Analysis of Education Service Quality Dimensions on Business School Students' Satisfaction

ERIC Educational Resources Information Center

Seng, Ernest Lim Kok; Ling, Tan Pei

2013-01-01

This study aims to investigate student satisfaction on quality education services provided by institutions of higher learning in Malaysia. Their level of satisfaction based primarily on the data collected through five dimensions of education service quality. A random sample of 250 students studying in an institution of higher learning was selected…

Investigating Teacher Candidates' Beliefs about Standardized Testing

ERIC Educational Resources Information Center

Kinay, Ismail; Ardiç, Tuncay

2017-01-01

The purpose of this study is to examine the beliefs of prospective teachers' about standardized testing in terms of some variables. This piece of research is in survey model. The study is carried out with 442 randomly selected prospective teachers registered in different departments at Dicle University in Turkey during the 2015-2016 academic year.…

Teaching Aptitude of Student Teachers and their Academic Achievements at Graduate Level

ERIC Educational Resources Information Center

Sajan, K. S.

2010-01-01

The present investigation aims at studying teaching aptitude of student teachers with respect to their gender and academic achievement at graduate level examination. The sample for this study is selected by stratified random sampling from the Teacher Education institutions of Malabar area of Kerala. Teaching Aptitude Test Battery (T A T B)…

Socio-Economic Background and Access to Internet as Correlates of Students' Achievement in Agricultural Science

ERIC Educational Resources Information Center

Adegoke, Sunday Paul; Osokoya, Modupe M.

2015-01-01

This study investigated access to internet and socio-economic background as correlates of students' achievement in Agricultural Science among selected Senior Secondary Schools Two Students in Ogbomoso South and North Local Government Areas. The study adopted multi-stage sampling technique. Simple random sampling was used to select 30 students from…

Estonian Science and Non-Science Students' Attitudes towards Mathematics at University Level

ERIC Educational Resources Information Center

Kaldo, Indrek; Reiska, Priit

2012-01-01

This article investigates the attitudes and beliefs towards studying mathematics by university level students. A total of 970 randomly chosen, first year, Estonian bachelor students participated in the study (of which 498 were science students). Data were collected using a Likert-type scale questionnaire and analysed with a respect to field of…

The Reasons for the Reluctance of Princess Alia University College Students' from Practicing Sports Activities

ERIC Educational Resources Information Center

Odat, Jebril

2015-01-01

This study aimed at investigating the reasons lying behind the reluctance of participation in sport activities among Alia Princess College female students, using descriptive approach. The population of the study consisted of (2000) female students, whereas the sample was of (200) students. They were randomly selected and a questionnaire of 31…

Level of Job Creativity among Learning Disabilities Teachers from Their Perspective in Kingdom of Saudi Arabia

ERIC Educational Resources Information Center

Hamadneh, Burhan M.

2016-01-01

The current study aims to identify the level of job creativity among learning disabilities teachers from their perspective in Kingdom of Saudi Arabia, and investigate the differences according to gender, scientific qualification and years of experience. The study sample consisted of (80) male and female teachers, who were randomly selected from…

Attitudes towards the Use of the Internet

ERIC Educational Resources Information Center

Al Otaibi, Khaled Nahes

2012-01-01

The main purpose of this study was to investigate the relationship between the attitude towards the use of the Internet and its cognitive, emotional and behavioral components. To achieve the objective of the study, the researcher used the scale of the attitude towards the Internet of a random sample of students (n = 216) at Teachers College at…

Young People's Perceptions of the Objective Physical Activity Monitoring Process: A Qualitative Exploration

ERIC Educational Resources Information Center

Scott, Joseph J.; Hansen, Vibeke; Morgan, Philip J.; Plotnikoff, Ronald C.; Lubans, David R.

2018-01-01

Objective: To explore young people's perceptions of pedometers and investigate behaviours exhibited while being monitored. Design: Qualitative design using six focus groups with participants (mean age 14.7 years). Setting: Study participants (n = 24) were randomly selected from a previous study of 123 young people aged 14-15 years from three…

Culture, Motivation, and Vocational Decision-Making of Australian Senior High School Students in Private Schools

ERIC Educational Resources Information Center

Jung, Jae Yup; McCormick, John; Gregory, Gary; Barnett, Kerry

2011-01-01

The purpose of this study was to investigate the roles of culture and motivation in the occupational decisions of senior high school students attending private schools. A theoretical framework guided the study. A questionnaire was administered to 492 Grade 11 students attending a stratified random sample of six independent (private) schools…

Prediction Accuracy: The Role of Feedback in 6th Graders' Recall Predictions

ERIC Educational Resources Information Center

Al-Harthy, Ibrahim S.

2016-01-01

The current study focused on the role of feedback on students' prediction accuracy (calibration). This phenomenon has been widely studied, but questions remain about how best to improve it. In the current investigation, fifty-seven students from sixth grade were randomly assigned to control and experimental groups. Thirty pictures were chosen from…

Reproduction accuracy of articulator mounting with an arbitrary face-bow vs. average values-a controlled, randomized, blinded patient simulator study.

PubMed

Ahlers, M Oliver; Edelhoff, Daniel; Jakstat, Holger A

2018-06-21

The benefit from positioning the maxillary casts with the aid of face-bows has been questioned in the past. Therefore, the aim of this study was to investigate the reliability and validity of arbitrary face-bow transfers compared to a process solely based on the orientation by means of average values. For optimized validity, the study was conducted using a controlled, randomized, anonymized, and blinded patient simulator study design. Thirty-eight undergraduate dental students were randomly divided into two groups; both groups were applied to both methods, in opposite sequences. Investigated methods were the transfer of casts using an arbitrary face-bow in comparison to the transfer using average values based on Bonwill's triangle and the Balkwill angle. The "patient" used in this study was a patient simulator. All casts were transferred to the same individual articulator, and all the transferred casts were made using type IV special hard stone plaster; for the attachment into the articulator, type II plaster was used. A blinded evaluation was performed based on three-dimensional measurements of three reference points. The results are presented three-dimensionally in scatterplots. Statistical analysis indicated a significantly smaller variance (Student's t test, p < 0.05) for the transfer using a face-bow, applicable for all three reference points. The use of an arbitrary face-bow significantly improves the transfer reliability and hence the validity. To simulate the patient situation in an individual articulator correctly, casts should be transferred at least by means of an arbitrary face-bow.

Practical issues regarding implementing a randomized clinical trial in a homeless population: strategies and lessons learned.

PubMed

Ojo-Fati, Olamide; Joseph, Anne M; Ig-Izevbekhai, Jed; Thomas, Janet L; Everson-Rose, Susan A; Pratt, Rebekah; Raymond, Nancy; Cooney, Ned L; Luo, Xianghua; Okuyemi, Kolawole S

2017-07-05

There is a critical need for objective data to guide effective health promotion and care for homeless populations. However, many investigators exclude homeless populations from clinical trials due to practical concerns about conducting research with this population. This report is based on our experience and lessons learned while conducting two large NIH-funded randomized controlled trials targeting smoking cessation among persons who are homeless. The current report also addresses challenges when conducting clinical trials among homeless populations and offers potential solutions. Homeless individuals face several challenges including the need to negotiate daily access to food, clothing, and shelter. Some of the critical issues investigators encounter include recruitment and retention obstacles; cognitive impairment, mental health and substance abuse disorders; transportation and scheduling challenges; issues pertaining to adequate study compensation; the need for safety protocols for study staff; and issues related to protecting the wellbeing of these potentially vulnerable adults. Anticipating realistic conditions in which to conduct studies with participants who are homeless will help investigators to design efficient protocols and may improve the feasibility of conducting clinical trials involving homeless populations and the quality of the data collected by the researchers. ClinicalTrials.gov, ID: NCT00786149 . Registered on 5 November 2008; ClinicalTrials.gov, ID: NCT01932996 . Registered on 20 November 2014.

Quantification of Randomly-methylated-{beta}-cyclodextrin effect on liposome: An ESR study

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

Grammenos, A., E-mail: A.Grammenos@ulg.ac.be; Bahri, M.A.; Guelluy, P.H.

2009-12-04

In the present work, the effect of Randomly-methylated-{beta}-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-{alpha} phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance (ESR) technique. The ability of Rameb to extract membrane cholesterol was demonstrated. For the first time, the percentage of cholesterol extracted by Rameb from cholesterol doped DMPC bilayer was monitored and quantified throughout a wide Rameb concentration range. The effect of cholesterol on the inner part of the membrane was also investigated using 16-doxyl stearic acid spin label (16-DSA). 16-DSA seems to explore two different membrane domains and report their respective microviscosities. ESR experiments also establishmore » that the presence of 30% of cholesterol in DMPC liposomes suppresses the jump in membrane fluidity at lipids phase-transition temperature (23.9 {sup o}C).« less

FIBER AND INTEGRAL OPTICS: Mode composition of radiation in graded-index waveguides with random microbending of the axis

NASA Astrophysics Data System (ADS)

Valyaev, A. B.; Krivoshlykov, S. G.

1989-06-01

It is shown that the problem of investigating the mode composition of a partly coherent radiation beam in a randomly inhomogeneous medium can be reduced to a study of evolution of the energy of individual modes and of the coefficients of correlations between the modes. General expressions are obtained for the coupling coefficients of modes in a parabolic waveguide with a random microbending of the axis and an analysis is made of their evolution as a function of the excitation conditions. An estimate is obtained of the distance in which a steady-state energy distribution between the modes is established. Explicit expressions are obtained for the correlation function in the case when a waveguide is excited by off-axial Gaussian beams or Gauss-Hermite modes.

Many-body delocalization with random vector potentials

NASA Astrophysics Data System (ADS)

Cheng, Chen; Mondaini, Rubem

2016-11-01

We study the ergodic properties of excited states in a model of interacting fermions in quasi-one-dimensional chains subjected to a random vector potential. In the noninteracting limit, we show that arbitrarily small values of this complex off-diagonal disorder trigger localization for the whole spectrum; the divergence of the localization length in the single-particle basis is characterized by a critical exponent ν which depends on the energy density being investigated. When short-range interactions are included, the localization is lost, and the system is ergodic regardless of the magnitude of disorder in finite chains. Our numerical results suggest a delocalization scheme for arbitrary small values of interactions. This finding indicates that the standard scenario of the many-body localization cannot be obtained in a model with random gauge fields.

A Randomized Controlled Trial to Assess the Effects of Competition on the Development of Laparoscopic Surgical Skills

PubMed Central

Hashimoto, Daniel A.; Gomez, Ernest D.; Beyer-Berjot, Laura; Khajuria, Ankur; Williams, Noel N.; Darzi, Ara; Aggarwal, Rajesh

2015-01-01

Background Serious games have demonstrated efficacy in improving participation in surgical training activities, but studies have not yet demonstrated the effect of serious gaming on performance. This study investigated whether competitive training affects laparoscopic surgical performance. Methods Twenty novices were recruited, and 18 (2 drop-outs) were randomized into control or competitive (CT) groups to perform 10 virtual reality (VR) laparoscopic cholecystectomies (LC). Competitiveness of each participant was assessed. The CT group was informed they were competing to outperform one another for a prize; performance ranking was shown prior to each session. The control group did not compete. Performance was assessed on time, movements, and instrument path length. Quality of performance was assessed with a global rating score (GRS). Results There were no significant intergroup differences in baseline skill or measured competitiveness. Time and GRS, at final LC, were not significantly different between groups; however, the CT group was significantly more dexterous than control and had significantly lower variance in number of movements and instrument path length at the final LC (p=0.019). Contentiousness was inversely related to time in the CT group. Conclusion This was the first randomized controlled trial to investigate if competitive training can enhance performance in laparoscopic surgery. Competitive training may lead to improved dexterity in laparoscopic surgery but yields otherwise similar performance to standard training in novices. Competition may have different effects on novices versus experienced surgeons, and subsequent research should investigate competitive training in experienced surgeons as well. PMID:26169566

Parenting program versus telephone support for Mexican parents of children with acquired brain injury: A blind randomized controlled trial.

PubMed

Chávez, Clara; Catroppa, Cathy; Hearps, Stephen J C; Yáñez-Téllez, Guillermina; Prieto-Corona, Belén; de León, Miguel A; García, Antonio; Sandoval-Lira, Lucero; Anderson, Vicki

2017-09-01

Acquired brain injury (ABI) during childhood typically causes behavior problems in the child and high levels of stress in the family. The aims of this study are: (1) to investigate the effectiveness and feasibility of a parenting intervention in improving behavior and self-regulation in Mexican children with ABI compared to telephone support; (2) to investigate the effectiveness and feasibility of a parenting intervention in improving parenting skills, parent self-efficacy and decreasing parental stress in parents of children with ABI compared to telephone support. Our secondary aims are (1) to explore the impact that parent characteristics have on the intervention outcomes; (2) to investigate if changes are maintained 3 months after the intervention. The research design is a blind randomized controlled trial (RCT). Eligible participants include children with a diagnosis of ABI, between 6 and 12 years of age, and their parents. Sixty-six children and their parents will be randomly allocated to either a parenting program group or telephone support group. The parenting program involves six face-to-face weekly group sessions of 2.5 h each. Participants in the control group receive an information sheet with behavioral strategies, and six weekly phone calls, in which strategies to improve academic skills are provided. Children and their parents are evaluated by blind assessors before the intervention, immediately after the intervention and 3-months post-intervention. This study will be the first to evaluate the efficacy and feasibility of a parenting program for Mexican parents of children with ABI. ACTRN12617000360314.

Feasibility and Efficacy of the Nintendo Wii Gaming System to Improve Balance Performance Post-Stroke: Protocol of a Phase II Randomized Controlled Trial in an Inpatient Rehabilitation Setting.

PubMed

Bower, Kelly J; Clark, Ross A; McGinley, Jennifer L; Martin, Clarissa L; Miller, Kimberly J

2013-04-01

Balance deficits following stroke are common and debilitating. Commercially available gaming systems, such as the Nintendo(®) (Kyoto, Japan) Wii™, have been widely adopted clinically; however, there is limited evidence supporting their feasibility and efficacy for improving balance performance following stroke. The aim of this trial is to investigate the clinical feasibility and efficacy of using the Nintendo Wii gaming system as an adjunct to standard care to improve balance performance following stroke in an inpatient rehabilitation setting. Thirty participants undergoing inpatient stroke rehabilitation will be recruited into this Phase II, single-blind, randomized controlled trial. Participants will be allocated into a Balance or Upper Limb Group, and both groups will perform activities using the Nintendo Wii in addition to their standard care. Participants will attend three 45-minute sessions per week, for a minimum of 2 and a maximum of 4 weeks. The main focus of the study is to investigate the feasibility of the intervention protocol. This will be evaluated through recruitment, retention, adherence, acceptability, and safety. The Step Test and Functional Reach Test will be the primary efficacy outcomes. Secondary outcomes will include force platform, mobility, and upper limb measures. Assessments will occur at baseline, 2 weeks, and 4 weeks after study entry. To the authors' knowledge, this will be the largest randomized clinical trial to investigate the feasibility and efficacy of the Nintendo Wii gaming system for improving balance performance in a stroke population. The results will inform the design of a Phase III multicenter trial.

A Randomized Controlled Trial to Assess the Effects of Competition on the Development of Laparoscopic Surgical Skills.

PubMed

Hashimoto, Daniel A; Gomez, Ernest D; Beyer-Berjot, Laura; Khajuria, Ankur; Williams, Noel N; Darzi, Ara; Aggarwal, Rajesh

2015-01-01

Serious games have demonstrated efficacy in improving participation in surgical training activities, but studies have not yet demonstrated the effect of serious gaming on performance. This study investigated whether competitive training (CT) affects laparoscopic surgical performance. A total of 20 novices were recruited, and 18 (2 dropouts) were randomized into control or CT groups to perform 10 virtual reality laparoscopic cholecystectomies (LCs). Competitiveness of each participant was assessed. The CT group members were informed they were competing to outperform one another for a prize; performance ranking was shown before each session. The control group did not compete. Performance was assessed on time, movements, and instrument path length. Quality of performance was assessed with a global rating scale score. There were no significant intergroup differences in baseline skill or measured competitiveness. Time and global rating scale score, at final LC, were not significantly different between groups; however, the CT group was significantly more dexterous than control and had significantly lower variance in number of movements and instrument path length at the final LC (p = 0.019). Contentiousness was inversely related to time in the CT group. This was the first randomized controlled trial to investigate if CT can enhance performance in laparoscopic surgery. CT may lead to improved dexterity in laparoscopic surgery but yields otherwise similar performance to that of standard training in novices. Competition may have different effects on novices vs experienced surgeons, and subsequent research should investigate CT in experienced surgeons as well. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Circulating Irisin Levels Are Not Affected by Coffee Intake: A Randomized Controlled Trial

PubMed Central

Peter, Patricia R.; Park, Kyung Hee; Huh, Joo Young; Wedick, Nicole M.; Mantzoros, Christos S.

2014-01-01

Irisin, secreted by skeletal muscle and possibly fat, is hypothesized to play an important role in modulating energy expenditure, obesity and metabolism. Coffee consumption also increases energy expenditure and leads to positive metabolic effects, but whether these effects are mediated by irisin remains unknown. The objective of this study was to determine the association between baseline irisin levels and the metabolic profile in humans and to investigate whether consumption of caffeinated coffee alters irisin levels. To this end, a secondary analysis was performed investigating irisin levels at baseline and after eight weeks in 32 healthy, overweight coffee drinkers who were randomized to consumption of 5 cups per day of instant caffeinated coffee, decaffeinated coffee, or water. Spearman correlation and analysis of covariance analyses were performed to identify possible associations. Irisin levels were positively correlated with waist circumference (r = 0.41, p = 0.02), fat mass (r = 0.44, p = 0.01) and CRP (r = 0.47, p = 0.007). Though there was a trend towards increased levels of irisin over time in the caffeinated coffee group (+1.8%) when compared to the placebo group (−4%) this did not reach statistical significance (p = 0.75 for the trend). This first randomized trial failed to reveal any effects of coffee consumption on irisin levels, but a larger trial, appropriately sized on the basis of data provided by this study, is needed to conclusively investigate such a relationship. Trial Registration Clinicaltrials.gov NCT00305097 PMID:24728416

Assessing the Status of Wild Felids in a Highly-Disturbed Commercial Forest Reserve in Borneo and the Implications for Camera Trap Survey Design

PubMed Central

Wearn, Oliver R.; Rowcliffe, J. Marcus; Carbone, Chris; Bernard, Henry; Ewers, Robert M.

2013-01-01

The proliferation of camera-trapping studies has led to a spate of extensions in the known distributions of many wild cat species, not least in Borneo. However, we still do not have a clear picture of the spatial patterns of felid abundance in Southeast Asia, particularly with respect to the large areas of highly-disturbed habitat. An important obstacle to increasing the usefulness of camera trap data is the widespread practice of setting cameras at non-random locations. Non-random deployment interacts with non-random space-use by animals, causing biases in our inferences about relative abundance from detection frequencies alone. This may be a particular problem if surveys do not adequately sample the full range of habitat features present in a study region. Using camera-trapping records and incidental sightings from the Kalabakan Forest Reserve, Sabah, Malaysian Borneo, we aimed to assess the relative abundance of felid species in highly-disturbed forest, as well as investigate felid space-use and the potential for biases resulting from non-random sampling. Although the area has been intensively logged over three decades, it was found to still retain the full complement of Bornean felids, including the bay cat Pardofelis badia, a poorly known Bornean endemic. Camera-trapping using strictly random locations detected four of the five Bornean felid species and revealed inter- and intra-specific differences in space-use. We compare our results with an extensive dataset of >1,200 felid records from previous camera-trapping studies and show that the relative abundance of the bay cat, in particular, may have previously been underestimated due to the use of non-random survey locations. Further surveys for this species using random locations will be crucial in determining its conservation status. We advocate the more wide-spread use of random survey locations in future camera-trapping surveys in order to increase the robustness and generality of inferences that can be made. PMID:24223717

Generalizability of causal inference in observational studies under retrospective convenience sampling.

PubMed

Hu, Zonghui; Qin, Jing

2018-05-20

Many observational studies adopt what we call retrospective convenience sampling (RCS). With the sample size in each arm prespecified, RCS randomly selects subjects from the treatment-inclined subpopulation into the treatment arm and those from the control-inclined into the control arm. Samples in each arm are representative of the respective subpopulation, but the proportion of the 2 subpopulations is usually not preserved in the sample data. We show in this work that, under RCS, existing causal effect estimators actually estimate the treatment effect over the sample population instead of the underlying study population. We investigate how to correct existing methods for consistent estimation of the treatment effect over the underlying population. Although RCS is adopted in medical studies for ethical and cost-effective purposes, it also has a big advantage for statistical inference: When the tendency to receive treatment is low in a study population, treatment effect estimators under RCS, with proper correction, are more efficient than their parallels under random sampling. These properties are investigated both theoretically and through numerical demonstration. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

The Impact of a Topical Sexual Enhancement Cream on the Female Sexual Response and Its Relationship to Clitoral Blood Flow.

PubMed

Pelekanos, Michael; Stofman, Guy M; Niren, Neil

2016-12-13

The aim of this investigation was to determine, through two Investigational Review Board (IRB)-approved studies, if a new topical vasodilating cream (NTVC; Life Science Enhancement Corporation, Pittsburgh PA) could improve female sexual response. Study I subjectively evaluated sexual female response as accessed by a modification of the Female Intervention Efficacy Index (FIEI). FIEI was developed at the University of California as an immediate outcome measure of medical intervention to treat female sexual dysfunction.1 In Study II, 10 randomly selected positive responders from Study I were subsequently analyzed objectively with clitoral plethysmography in order to determine the effect of the NTVC and placebo on blood flow.2 RESULTS: In the subjective Study I (81 patients ranging in age from 18 to 63), a positive response trend for the NTVC was demonstrated compared to the placebo. In the objective Study II, 10 randomly selected patients who responded positive in Study I were objectively evaluated for response of increased blood flow in the clitoris after application of both the NTVC and placebo. The clitoral blood flow was shown to have increased with statistical significance for the NTVC in all 10 patients compared to the placebo, with the NTVC exhibiting an average 69% increase in clitoral blood flow. The female sexual response is complex. In the subjective Study I, the NTVC demonstrated positive trends for enhanced lubrication, genital sensation, intercourse, and overall sexual experience. In the objective Study II, 10 of the positive subjective responders from Study I were randomly selected to evaluate their response to the NTVC compared to the placebo. This was done via Doppler plethysmography (DP). All 10 patients demonstrated a statistically significant response rate for increase in clitoral blood flow using the NTVC compared to the placebo, with an average blood flow increase of 69%. This portion of the investigation demonstrates a significant positive end organ response to the NTVC. The positive subjective trends combined with the significant and substantial increase in clitoral blood flow may result in enhanced female sexual satisfaction.

[Three-dimensional parallel collagen scaffold promotes tendon extracellular matrix formation].

PubMed

Zheng, Zefeng; Shen, Weiliang; Le, Huihui; Dai, Xuesong; Ouyang, Hongwei; Chen, Weishan

2016-03-01

To investigate the effects of three-dimensional parallel collagen scaffold on the cell shape, arrangement and extracellular matrix formation of tendon stem cells. Parallel collagen scaffold was fabricated by unidirectional freezing technique, while random collagen scaffold was fabricated by freeze-drying technique. The effects of two scaffolds on cell shape and extracellular matrix formation were investigated in vitro by seeding tendon stem/progenitor cells and in vivo by ectopic implantation. Parallel and random collagen scaffolds were produced successfully. Parallel collagen scaffold was more akin to tendon than random collagen scaffold. Tendon stem/progenitor cells were spindle-shaped and unified orientated in parallel collagen scaffold, while cells on random collagen scaffold had disorder orientation. Two weeks after ectopic implantation, cells had nearly the same orientation with the collagen substance. In parallel collagen scaffold, cells had parallel arrangement, and more spindly cells were observed. By contrast, cells in random collagen scaffold were disorder. Parallel collagen scaffold can induce cells to be in spindly and parallel arrangement, and promote parallel extracellular matrix formation; while random collagen scaffold can induce cells in random arrangement. The results indicate that parallel collagen scaffold is an ideal structure to promote tendon repairing.

Ferromagnetic clusters induced by a nonmagnetic random disorder in diluted magnetic semiconductors

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

Bui, Dinh-Hoi; Physics Department, Hue University’s College of Education, 34 Le Loi, Hue; Phan, Van-Nham, E-mail: phanvannham@dtu.edu.vn

In this work, we analyze the nonmagnetic random disorder leading to a formation of ferromagnetic clusters in diluted magnetic semiconductors. The nonmagnetic random disorder arises from randomness in the host lattice. Including the disorder to the Kondo lattice model with random distribution of magnetic dopants, the ferromagnetic–paramagnetic transition in the system is investigated in the framework of dynamical mean-field theory. At a certain low temperature one finds a fraction of ferromagnetic sites transiting to the paramagnetic state. Enlarging the nonmagnetic random disorder strength, the paramagnetic regimes expand resulting in the formation of the ferromagnetic clusters.

Clinical Effectiveness Research in Managed-care Systems: Lessons from the Pediatric Asthma Care PORT

PubMed Central

Finkelstein, Jonathan A; Lozano, Paula; Streiff, Kachen A; Arduino, Kelly E; Sisk, Cynthia A; Wagner, Edward H; Weiss, Kevin B; Inui, Thomas S

2002-01-01

Objective To highlight the unique challenges of evaluative research on practice behavior change in the “real world” settings of contemporary managed-care organizations, using the experience of the Pediatric Asthma Care PORT (Patient Outcomes Research Team). Study Setting The Pediatric Asthma Care PORT is a five-year initiative funded by the Agency for Healthcare Research and Quality to study strategies for asthma care improvement in three managed-care plans in Chicago, Seattle, and Boston. At its core is a randomized trial of two care improvement strategies compared with usual care: (1) a targeted physician education program using practice based Peer Leaders (PL) as change agents, (2) adding to the PL intervention a “Planned Asthma Care Intervention” incorporating joint “asthma check-ups” by nurse-physician teams. During the trial, each of the participating organizations viewed asthma care improvement as an immediate priority and had their own corporate improvement programs underway. Data Collection Investigators at each health plan described the organizational and implementation challenges in conducting the PAC PORT randomized trial. These experiences were reviewed for common themes and “lessons” that might be useful to investigators planning interventional research in similar care-delivery settings. Conclusions Randomized trials in “real world” settings represent the most robust design available to test care improvement strategies. In complex, rapidly changing managed-care organizations, blinding is not feasible, corporate initiatives may complicate implementation, and the assumption that a “usual care” arm will be static is highly likely to be mistaken. Investigators must be prepared to use innovative strategies to maintain the integrity of the study design, including: continuous improvement within the intervention arms, comanagement by researchers and health plan managers of condition-related quality improvement initiatives, procedures for avoiding respondent burden in health plan enrollees, and anticipation and minimization of risks from experimental arm contamination and major organizational change. With attention to these delivery system issues, as well as the usual design features of randomized trials, we believe managed-care organizations can serve as important laboratories to test care improvement strategies. PMID:12132605